CN110999400B

CN110999400B - Method and apparatus for controlling access in next generation mobile communication system

Info

Publication number: CN110999400B
Application number: CN201880050623.6A
Authority: CN
Inventors: 金相范; 金东建; A.萨延科; 张宰赫; 陈胜利; 金成勋
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2017-08-03
Filing date: 2018-08-03
Publication date: 2022-12-06
Anticipated expiration: 2038-08-03
Also published as: EP3649805A1; CN110999400A; EP3649805A4

Abstract

An apparatus and method for applying a 5G communication system to an IoT network are provided. The apparatus includes technologies such as sensor networks, machine Type Communication (MTC), and machine-to-machine (M2M) communication, which may be implemented by beamforming, multiple Input Multiple Output (MIMO), and array antennas. The application of cloud Radio Access Network (RAN) as the big data processing technology described above can also be considered as an example of the convergence between 5G technology and IoT technology. The present disclosure relates to a method and apparatus for controlling network access in a next generation mobile communication system.

Description

Method and apparatus for controlling access in next generation mobile communication system

Technical Field

The present disclosure relates to a method and apparatus for controlling access in a next generation mobile communication system. More particularly, the present disclosure relates to a receiver triggered Packet Data Convergence Protocol (PDCP) status reporting method in a next generation mobile communication system.

Background

In order to meet the increasing demand for wireless data traffic since the Fourth Generation (4G) communication system deployment, efforts have been made to develop improved Fifth Generation (5G) or pre-5G communication systems. Accordingly, the 5G or pre-5G communication system is also referred to as a "super 4G network" or a "Long Term Evolution (LTE) system". The 5G communication system is considered to be implemented in a millimeter wave (mmWave) frequency band of a higher frequency (e.g., 60GHz band) in order to achieve a higher data rate. In order to reduce propagation loss of radio waves and increase transmission distance, beamforming, massive Multiple-Input Multiple-Output (MIMO), full-Dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and massive antenna techniques are discussed in the 5G communication system. Further, in the 5G communication system, development of system Network improvement based on advanced small cells, cloud Access Network (RAN), ultra-dense Network, device-to-Device (D2D) communication, wireless backhaul, mobile Network, cooperative communication, coordinated Multi-Point (CoMP), reception-side interference cancellation, and the like is underway. In the 5G system, hybrid Frequency-Shift Keying (FSK) And Quadrature Amplitude Modulation (QAM), frequency And Quadrature Amplitude Modulation (FQAM), and Sliding Window Superposition Coding (SWSC) have been developed as Advanced Coding Modulation (ACM) technologies, and filterbank multicarrier (FBMC), non-Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA) have been developed as Advanced Access technologies.

The Internet, which is a human-centric network-connected Internet in which humans generate and consume information, is now evolving into the Internet of Things (IoT), in which distributed entities, such as Things, exchange and process information without human intervention. Internet of Everything (IoE) has emerged as an IoT technology and a big data processing technology combined through a connection with a cloud server. As the IoT enforces the demand for technical elements such as "sensing technology", "wired/wireless Communication and network infrastructure", "service interface technology", and "security technology", sensor networks, machine-to-Machine (M2M) Communication, machine Type Communication (MTC), etc. have recently been studied. Such IoT environments can provide intelligent internet technology services that create new value for human life by collecting and analyzing data generated between internet things. Through the convergence and combination of existing Information Technology (IT) and various industrial applications, ioT may be applied in various fields including smart homes, smart buildings, smart cities, smart cars or networked cars, smart grids, healthcare, smart homes, and advanced medical services.

In line with this, various attempts have been made to apply the 5G communication system to the IoT network. For example, techniques such as sensor networks, MTC, and M2M communication may be implemented by beamforming, MIMO, and array antennas. The application of cloud Radio Access Network (RAN) as the big data processing technology described above can also be considered as an example of the convergence between 5G technology and IoT technology.

The above information is presented as background information only to aid in understanding the present disclosure. No determination is made, nor is an assertion as to whether any of the above can be applied as prior art to the present disclosure.

Disclosure of Invention

[ problem ] to provide a method for producing a semiconductor device

An aspect of the present disclosure is to address at least the above problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present disclosure is to provide a method and apparatus for controlling access in a next generation mobile communication system.

Another aspect of the present disclosure is to provide a method and apparatus for controlling access of a terminal.

Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments.

Further, the present disclosure specifies a portion to be modified in a packet delay tolerance report applied to a wireless communication system (LTE system), and detailed operations required to apply the packet delay tolerance report to a next generation mobile communication system. The packet delay tolerance report is used to adjust Discontinuous Reception (DRX) to improve Voice over LTE (VoLTE) performance and enhance data (Physical Uplink Shared Channel (PUSCH)) transmission to extend coverage. For example, the terminal transmits an RRC report message to request a DRX cycle and repeat retransmission period, thereby improving a delay tolerance level and extending a coverage according to the current VoLTE call quality.

In the next generation mobile communication system supporting a high data rate, if PDCP PDUs are lost or arrive with a delay in a single connection environment, if the PDCP PDUs are discarded at a transmitter due to the expiration of a PDCP expiration timer, or if one of two PDCP entities delays receiving the PDCP PDUs in a dual connection environment, all received data should be stored in a buffer until a reordering timer triggered at a receiving PDCP layer expires, thereby causing a transmission delay. Therefore, the terminal must have a large capacity memory or buffer to store all data received while the reordering timer is running. Data loss may occur if the memory or buffer capacity is insufficient. If data that has triggered the PDCP reordering timer arrives before the timer expires or if the PDCP reordering timer expires, a large amount of data received while the timer is running may be delivered to an upper layer at once, and thus the upper layer may not be able to process all data, resulting in data loss.

[ problem solution ] to provide a solution for the above problems

According to an aspect of the present disclosure, there is provided an access control method of a terminal in a wireless communication system. The method comprises the following steps: if an access is triggered, the access type of the triggered access is checked, and the access type of the triggered access is determined as a predetermined access category based on the checked access type.

Preferably, determining the access type of the triggered access as the access category comprises: determining whether the checked access type is an emergency access type (emergency access type), and if the checked access type is the emergency access type, determining the triggered access type as a first access category related to the emergency access type.

Preferably, the method further comprises, if the checked access type is not the emergency access type, determining whether the triggered access type is an operator-provided service access type (operator-provided service access type), and if the triggered access type is the operator-provided service access type, determining the triggered access type as a second access category related to the operator-provided service access type.

Preferably, the method further comprises determining the triggered access type as a third access category if the checked access type is not an operator provided service access type.

Preferably, the method further comprises receiving information from the operator server about a second access category associated with the operator provided service access type.

Preferably, the method further comprises receiving information on the list of access categories from the base station, and determining the access type of the triggered access as the predetermined access category comprises determining the access type of the triggered access based on the checked access type and the information on the list of access categories.

Preferably, the method further comprises determining whether to perform the triggered access based on the determined access category, and transmitting a connection request message to the base station if it is determined to perform the triggered access.

According to another aspect of the present disclosure, a terminal of a wireless communication system is provided. The terminal includes a transceiver and at least one processor configured to control to: if an access is triggered, the access type of the triggered access is checked, and the access type of the triggered access is determined as a predetermined access category based on the checked access type.

Preferably, the at least one processor is configured to control to: it is determined whether the checked access type is an emergency access type, and if the checked access type is the emergency access type, the triggered access type is determined as a first access category related to the emergency access type.

Preferably, the at least one processor is configured to control to: if the checked access type is not an emergency access type, determining whether the triggered access type is an operator provided service access type, and if the triggered access type is an operator provided service access type, determining the triggered access type as a second access category related to the operator provided service access type.

Preferably, the at least one processor is configured to control to: and if the detected access type is not the operator-provided service access type, determining the triggered access type as a third access category.

Preferably, the at least one processor is configured to control the transceiver to receive information from the operator server regarding a second access category associated with the operator provided service access type.

Preferably, the at least one processor is configured to control the transceiver to receive information on the list of access categories from the base station, the access type of the triggered access being determined based on the checked access type and the information on the list of access categories.

Preferably, the at least one processor is configured to control to: determining whether to perform the triggered access based on the determined access category, and controlling the transceiver to transmit a connection request message to the base station if it is determined to perform the triggered access.

Preferably, the at least one processor is configured to determine whether to perform the triggered access based on the determined access category and the triggered access type.

Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure.

[ advantageous effects of the invention ]

As described above, the present disclosure is advantageous in facilitating network access in a next generation mobile communication system.

Further, the access control method of the present disclosure is advantageous in improving system throughput by effectively controlling access of a UE.

Further, the PDCP status reporting method of the present disclosure is advantageous in solving the problems of transmission delay and data loss caused by a reordering timer running at a receiver, that is, in the following manner: when a predetermined timer operating at the receiving PDCP layer expires, when the amount of data stored in a reception buffer becomes equal to or greater than a threshold value, or when a reordering timer value reaches a predetermined time, the receiver triggers a PDCP status report and transmits the PDCP status report to the transmitter, which receives and checks the PDCP status report to discard data (PDCP PDUs or PDCP SDUs) successfully received by the receiver and rapidly retransmits the lost data.

Furthermore, the UE-assisted packet delay budget reporting method of the present disclosure is advantageous in clarifying the operation of the UE and the gNB by modifying and explicitly defining the operation for legacy LTE systems. Further, the UE-assisted packet delay budget reporting method of the present disclosure is advantageous in being applicable to next generation mobile communication systems.

Drawings

The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

fig. 1A is a diagram showing an architecture of a next generation mobile communication system according to an embodiment of the present disclosure;

fig. 1B is a diagram illustrating a method for determining whether to accept access in a legacy Long Term Evolution (LTE) system according to an embodiment of the present disclosure;

fig. 1C is a diagram illustrating a procedure of an Application Specific Congestion Control for Data Communication (ACDC) operation for performing Data Communication in a conventional LTE system according to an embodiment of the present disclosure;

fig. 1D is a diagram illustrating the structure of ACDC configuration information used in a conventional LTE system according to an embodiment of the present disclosure;

fig. 1E is a diagram illustrating a process of UE access control operation according to an embodiment of the present disclosure;

fig. 1F is a flowchart illustrating a User Equipment (UE) Non-Access Stratum (NAS) operation according to an embodiment of the present disclosure;

fig. 1G is a signal flow diagram illustrating an access control procedure according to an embodiment of the present disclosure;

fig. 1H is a flowchart illustrating a UE NAS operation according to embodiment 2 of the present disclosure;

fig. 1I is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure;

fig. 1J is a block diagram illustrating a configuration of a new radio Node B (gNB) according to an embodiment of the present disclosure;

fig. 2A is a signal flow diagram illustrating an access control procedure according to an embodiment of the present disclosure;

fig. 2B is a flowchart illustrating a UE NAS operation according to embodiment 2-1 of the present disclosure;

FIG. 2C is a flowchart illustrating UE AS operation according to embodiment 2-1 of the present disclosure;

FIG. 2D is a flowchart illustrating UE NAS operation according to embodiment 2-2 of the present disclosure;

FIG. 2E is a flowchart illustrating UE AS operation according to embodiment 2-2 of the present disclosure;

fig. 2F is a signal flow diagram for a network to provide various types of barring configuration information for access control to a UE in accordance with an embodiment of the present disclosure;

fig. 3A is a signal flow diagram illustrating a process for providing system information in a next generation mobile communication system according to an embodiment of the present disclosure;

fig. 3B is a signal flow diagram illustrating a random access procedure in a conventional LTE system according to an embodiment of the present disclosure;

fig. 3C is a flowchart illustrating a procedure for selecting one of a System Information (SI) request method based on msg1 and an SI request message based on msg3 according to an embodiment of the present disclosure;

fig. 3D is a signal flow diagram illustrating a service request processing procedure in a process of requesting system information according to embodiment 3-1 of the present disclosure;

fig. 3E is a signal flow diagram illustrating a process of processing a service request in a process of requesting system information according to embodiment 3-2 of the present disclosure;

fig. 4A is a diagram showing an architecture of a next generation mobile communication system according to an embodiment of the present disclosure;

fig. 4B is a diagram illustrating a method for determining whether to accept access in a legacy LTE system according to an embodiment of the present disclosure;

fig. 4C is a diagram illustrating a process for performing ACDC operation in a legacy LTE system, according to an embodiment of the present disclosure;

fig. 4D is a diagram illustrating a structure of ACDC configuration information used in a conventional LTE system according to an embodiment of the present disclosure;

fig. 4E is a diagram illustrating a process of UE access control operation according to an embodiment of the present disclosure;

fig. 4F is a signal flow diagram illustrating an access control procedure according to an embodiment of the present disclosure;

fig. 4G is a diagram illustrating a method for configuring access barring configuration information according to an embodiment of the present disclosure;

FIG. 4H is a flowchart illustrating the operation of the UE NAS according to an embodiment of the present disclosure;

FIG. 4I is a flow chart illustrating operation of a UE AS according to an embodiment of the present disclosure;

fig. 4J is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure;

fig. 4K is a block diagram illustrating a configuration of a gNB according to an embodiment of the present disclosure;

fig. 5A is a diagram illustrating an architecture of an LTE system according to an embodiment of the present disclosure;

fig. 5B is a diagram illustrating a protocol stack of an interface between a UE and an eNB in an LTE system according to an embodiment of the present disclosure;

fig. 5C is a diagram showing an architecture of a next generation mobile communication system according to an embodiment of the present disclosure;

fig. 5D is a diagram illustrating a protocol stack of an interface between a New Radio (NR) UE and an NR gNB in a next generation mobile communication system according to an embodiment of the present disclosure;

fig. 5E is a signal flow diagram illustrating a process by which the gNB configures a Packet Data Convergence Protocol (PDCP) status report request function via an RRC message when the UE establishes a connection with the network, according to an embodiment of the present disclosure;

fig. 5F is a diagram illustrating a transmission delay and data loss problem caused by a PDCP reordering timer of a PDCP entity according to an embodiment of the present disclosure;

fig. 5G is a diagram illustrating a format of a first type PDCP status report according to an embodiment of the present disclosure;

figure 5H depicts a flowchart illustrating the operation of a sending PDCP entity and a receiving PDCP entity for handling a proposed PDCP status report according to an embodiment of the present disclosure;

fig. 5I is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure;

fig. 5J is a block diagram illustrating a configuration of a gNB according to an embodiment of the present disclosure;

fig. 6A is a diagram illustrating an architecture of an LTE system according to an embodiment of the present disclosure;

fig. 6B is a diagram illustrating a protocol stack of an interface between a UE and an eNB in an LTE system according to an embodiment of the present disclosure;

fig. 6C is a diagram showing an architecture of a next generation mobile communication system according to an embodiment of the present disclosure;

fig. 6D is a diagram illustrating a protocol stack of an interface between an NR UE and an NR gNB in a next generation mobile communication system according to an embodiment of the present disclosure;

fig. 6E is a diagram illustrating a Discontinuous Reception (DRX) operation of a UE in an idle mode in an LTE system according to an embodiment of the present disclosure;

fig. 6F is a diagram illustrating a DRX operation of a UE in a Radio Resource Control (RRC) connected mode in an LTE system according to an embodiment of the present disclosure;

fig. 6G is a diagram illustrating a packet delay budget reporting operation for improving the quality of voice over LTE (VoLTE) in a wireless communication system according to an embodiment of the disclosure;

fig. 6H is a diagram illustrating a packet transmission delay measurement method of an item in a VoLTE system according to an embodiment of the present disclosure;

fig. 6I is a signal flow diagram illustrating a method for a UE to request a Connected Mode Discontinuous Reception (CDRX) period change and to transmit and receive data with the changed CDRX period according to an embodiment of the present disclosure;

fig. 6J is a flowchart illustrating a CDRX cycle change procedure of a UE according to an embodiment of the present disclosure;

fig. 6K is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure;

fig. 6L is a block diagram illustrating a configuration of a gNB according to an embodiment of the present disclosure;

fig. 7A is a diagram showing an architecture of a next generation mobile communication system according to an embodiment of the present disclosure;

fig. 7B is a diagram illustrating a method for determining whether to accept access in a legacy LTE system according to an embodiment of the present disclosure;

fig. 7C is a diagram illustrating a process for performing ACDC operation in an LTE system according to an embodiment of the disclosure;

fig. 7D is a diagram illustrating the structure of ACDC configuration information used in an LTE system according to an embodiment of the present disclosure;

fig. 7E is a diagram illustrating a process for controlling access of a UE in a connected mode or an inactive mode according to an embodiment of the present disclosure;

fig. 7F is a signal flow diagram illustrating an access control procedure for a UE in a connected mode or an inactive mode according to an embodiment of the present disclosure;

FIG. 7G is a flowchart illustrating the operation of the UE NAS according to an embodiment of the present disclosure;

FIG. 7H is a flowchart illustrating operation of a UE AS according to an embodiment of the present disclosure;

fig. 7I is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure; and

fig. 7J is a block diagram illustrating a configuration of a gNB according to an embodiment of the present disclosure.

Throughout the drawings, like reference numerals will be understood to refer to like parts, components and structures.

Detailed Description

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details that are helpful in understanding, but these are to be considered merely illustrative. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. Also, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the written meaning, but are used only by the inventors to enable a clear and consistent understanding of the disclosure. Therefore, it will be apparent to those skilled in the art that the following descriptions of the various embodiments of the present disclosure are provided for illustration only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

The term "substantially" means that the recited characteristic, parameter, or value need not be precisely taken, but may be offset or varied in an amount that does not preclude the effect that the characteristic is intended to provide, including for example, tolerances, measurement error, measurement accuracy limitations, and other factors known to those of skill in the art.

A detailed description of well-known functions and configurations incorporated herein may be omitted to avoid obscuring the subject matter of the present disclosure. This is intended to omit unnecessary description in order to clarify the subject matter of the present disclosure.

For the same reason, some elements are enlarged, omitted or simplified in the drawings, and in practice, the elements may have sizes and/or shapes different from those shown in the drawings. The same reference numbers will be used throughout the drawings to refer to the same or like parts.

Advantages and features of the present disclosure and methods of accomplishing the same may be understood more readily by reference to the following detailed description of the embodiments and the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art, and the present disclosure will only be defined by the appended claims. Like reference numerals refer to like elements throughout the specification.

It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a non-transitory computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the non-transitory computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational operations to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide operations for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

Further, various block diagrams may illustrate modules, segments, or portions of code comprising at least one or more executable instructions for implementing the specified logical function(s). Further, it should be noted that in some modifications, the functions of the blocks may be performed in a different order. For example, two consecutive blocks may be executed substantially concurrently, or may be executed in reverse order depending on their functions.

According to various embodiments of the present disclosure, the term "module" refers to, but is not limited to, a software or hardware component, such as a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), that performs a Specific task. A module may advantageously be configured to reside on the addressable storage medium and configured to execute on one or more processors. Thus, a module may include, by way of example, components (such as software components, object-oriented software components, class components and task components), processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functionality provided for in the components and modules may be combined into fewer components and modules or further separated into additional components and modules. Further, the components and modules may be implemented such that they execute one or more Central Processing Units (CPUs) in a device or secure multimedia card. According to various embodiments of the present disclosure, a module may include at least one processor.

Example 1

Fig. 1A is a diagram illustrating an architecture of a next generation mobile communication system according to an embodiment of the present disclosure.

Referring to fig. 1A, a Radio access Network 1A-20 of a next generation mobile communication system includes a New Radio Node B (NR NB) 1A-10 and a New Radio Core Network (NR CN) 1A-05. The new radio user equipment (hereinafter referred to as new radio user equipment (NR UE) or simply UE) 1a-15 is connected to the external network via NR NB 1a-10 and NR CN 1a-05.

In fig. 1A, NR NBs 1A-10 correspond to evolved Node bs (enbs) in a conventional LTE system. The NR UEs 1a-15 are connected to a NR NB which can provide services superior to conventional enbs. In the next generation mobile communication system in which all user traffic is served through a shared channel, an entity is required to collect UE-specific state information (such as buffer status, power headroom status, and channel status) and schedule UEs based on the collected information, and the NR NBs 1a-10 are responsible for these functions. Generally, one NRNB carries a plurality of cells. In order to meet the higher data rate requirement than the conventional LTE, it is necessary to secure a maximum bandwidth wider than ever by employing advanced techniques such as Orthogonal Frequency Division Multiplexing (OFDM) as a radio access scheme and beamforming. Adaptive Modulation And Coding (AMC) techniques may be employed to determine the Modulation scheme And channel Coding rate to adapt to the channel conditions of the UE. The NR CN1a-05 is responsible for mobility management, bearer establishment and QoS establishment. The NR CN1a-05 is responsible for other control functions as well as UE mobility management functions related to multiple NR NBs. The next generation mobile communication system can interoperate with the conventional LTE system in such a manner that the NR CN1a-05 is connected to a Mobility Management Entity (MME) 1a-25 through a network interface. The MME 1a-25 is connected to the eNBs 1a-30, which are legacy base stations.

Fig. 1B is a diagram illustrating a method for determining whether to accept access in a legacy LTE system according to an embodiment of the present disclosure.

Referring to fig. 1B, generally, the functionality of an LTE UE is divided into an Access Stratum (AS) 1B-15 and a non-Access Stratum (NAS) 1B-05. The AS is responsible for all access related functions and the NAS is responsible for non-access related functions such AS Public Land Mobile Network (PLMN) selection and service requests. The accessibility determination may be primarily determined by the UE AS. As mentioned above, a network in congestion may restrict new accesses and for this purpose it broadcasts relevant configuration information for each UE to make its own access determination, as indicated by reference numerals 1 b-35. With the introduction of new requirements in legacy LTE systems, new barring mechanisms have been proposed, as a result of which multiple access barring checks are allowed. If the UE NAS layer issues a service request, AS indicated by reference numerals 1b-10, the UE AS checks if the UE can actually access the network. If the establishment cause value of the service request is "delay tolerant Access", the UE AS first performs Extended Access Barring (EAB), AS indicated by reference numerals 1 b-20. The EAB barring mechanism is performed as an access check procedure applicable only to Machine Type Communication (MTC). If the EAB check is passed, the UE AS performs dedicated congestion control for data communication (ACDC), AS indicated by reference numerals 1 b-55. The application requesting the service is assigned an ACDC category whose value may be included in the service request transmitted to the UE AS. The network may provide prohibited configuration information per ACDC category. Thus, the access checking procedure may be performed in groups, which are classified by ACDC categories. If the barring configuration information per ACDC category is not provided by the network, the UE AS omits the ACDC access checking procedure. If the ACDC check is passed, the UE AS performs Access Class Barring (ACB), AS indicated by reference numerals 1 b-30. The ACB is an access check procedure using barring configuration information separately provided according to Mobile Originating (MO) data or MO signaling. For Multiple Telephone (MMTEL) voice/video/SMS services, the ACB procedure may be omitted using the ACB skip indicator, as shown at reference numerals 1 b-25. The UE AS may attempt to access the network if all of the above access checking procedures are passed. For example, the UE AS performs random access and transmits a Radio Resource Control (RRC) connection request message to the eNB, AS indicated by reference numerals 1 b-40. There may be another access check procedure that is not performed by the UE AS. If barring configuration information (SSAC) of MMTEL voice/video is received from the network, AS indicated by reference numerals 1b-45, the UE AS transfers this information to the IMS layer responsible for managing the services in the UE, AS indicated by reference numerals 1 b-50. After receiving the barring configuration information, the IMS layer may perform an access check procedure when the service is triggered. SSAC, when introduced, is designed to cause the UE AS to perform a corresponding function regardless of the type of application or service. Therefore, in order to control the determination as to whether to accept access to a specific service (such as MMTEL voice/video), it is necessary to directly transfer the barring configuration information to a layer managing the service so that the corresponding layer performs an access check procedure.

In the next generation mobile communication system, such a complicated procedure is unnecessary. This is because it is possible to design a single access checking procedure that contains all the requirements introduced in LTE from the beginning. The present disclosure proposes a single barring mechanism evolved from the traditional ACDC access checking procedure.

Fig. 1C is a diagram illustrating a process for performing ACDC operation in a legacy LTE system according to an embodiment of the present disclosure.

Referring to fig. 1C, in a conventional LTE system, ACDC has been proposed to make an accessibility determination for each application (service). Each application is assigned at least one ACDC category value. ACDC category values are selected in the range of 1 to 16. At operation 1c-25, the network 1c-20 provides the ACDC category information per application to the UE NAS1c-10 using NAS messages. At operation 1c-50, the network 1c-20 provides the UE AS 1c-15 with barring configuration Information to be applied to each ACDC category using the System Information Block 2 (System Information Block 2, SIB 2). The barring configuration Information includes an ac-BarringFactor Information Element (IE) and an ac-Barringtime IE. The value of the ac-BarringFactor alpha is within the range of more than or equal to 0 and less than or equal to 1. UE AS 1c-15 extracts random values of rand within the range of more than or equal to 0 and less than or equal to rand < 1; if the random value is less than ac-BarringFactor, then access is assumed not to be barred, and if not, then access is assumed to be barred. If it is determined that access is barred, UE AS 1c-15 delays the access attempt for a duration based on the following equation.

"Tbarring" (0.7 +0.6 + rand). Ac-BarringTime. Equation 1

If a service request is triggered, at operation 1c-30, the UE AS 1c-15 extracts the ACDC category value for the application corresponding to the service. At operation 1c-35, the UE NAS1c-10 sends a service request including the ACDC class value to the UE AS1 c-15. Upon receiving the service request, at operation 1c-40, the UE AS 1c-15 determines whether access is accepted according to the ACDC category value based on ACDC barring configuration information included in SIB 2. If SIB2 does not include barring configuration information corresponding to the ACDC category, then it is assumed that applications belonging to the ACDC category are allowed access during ACDC. If access is allowed by the access barring check procedure, the UE AS 1c-15 sends an RRC connection request for random access to the network at operation 1 c-45.

Fig. 1D is a diagram illustrating a structure of ACDC configuration information used in a conventional LTE system according to an embodiment of the present disclosure.

Referring to fig. 1d, ACDC configuration information (ACDC-BarringForCommon-r 13) 1d-10 may provide PLMN-specific forbidden configuration information sets (ACDC-BarringPerPLMN 1, ACDC-BarringPerPLMN 2.) -1 d-35 and 1d-40. If all PLMNs have the same barring configuration information set, one barring configuration information set (ACDC-BarringForCommon-r 13) 1d-05 may be set most widely. The PLMN-specific barring configuration information or the set of common barring configuration information comprises category-specific barring configuration information 1d-20, 1d-25 and 1d-30. As described above, the disabling configuration information 1d-45 includes the ac-BarringFactor IE and the ac-Barringtime IE. If there is no barring configuration information for a particular ACDC category, it is assumed that applications belonging to the corresponding ACDC category are not barred by the ACDC.

Fig. 1E is a diagram illustrating a procedure of a UE access control operation according to an embodiment of the present disclosure.

Referring to fig. 1E, the present disclosure proposes a category-based access control scheme similar to a conventional ACDC. However, the proposed access control scheme differs from the conventional ACDC in that the classification is made with other elements and applications, such as service access type, call type, UE class, user group, signaling type, slice type and any combination thereof. For example, access control may be performed for certain element-specific access types. In the present disclosure, access is classified into two categories. One of the two categories is the standardized access category. The category is defined at the RAN level, i.e. is explicitly classified in standard documents. In the present disclosure, the emergency related category belongs to the standard access category. Each access belongs to at least one standardized access category. The other is a non-standardized access category. This category is defined outside of the third Generation Partnership project (3 GPP) architecture and is therefore not explicitly classified in standard documentation. This is the same characteristic of the categories in a traditional ACDC. However, a particular access triggered by the UE NAS may not be mapped to a non-standardized access category. The operator's server 1e-25 provides the UE NAS1e-10 with non-standardized class information via NAS signaling or application layer data transmission. The non-standardized category information provides a mapping between the non-standardized category and a classification element (such as an application). The new radio Node B (gNB) 1e-20 uses the system information to provide the UE with a list of categories containing barring configuration information and the barring configuration information per category. UE AS 1e-15 sends the category list provided by gNB 1e-20 to UE NAS1 e-10. The UE NAS1e-10 maps the triggered access to one of the categories according to a predetermined rule. The UE NAS1e-10 sends information about the mapped categories and a service request to the UE AS1 e-15. The UE AS 1e-15 determines whether to allow the access triggered by the UE NAS1e-10 based on the barring configuration information (barring check).

Examples 1 to 1

The present disclosure proposes a method for mapping an access triggered by a UE NAS to a specific class. In embodiment 1-1, the UE NAS maps access to one category.

In embodiment 1-1, access is mapped to at least one standardized access category. Furthermore, access may not be mapped to any subcategories of non-standardized access categories provided by the network. In the present disclosure, the category provided by the network for mapping access thereto is assigned at least one predetermined priority. The triggered access is mapped to the category with the highest priority among the categories to which the access can be mapped. In the present disclosure, the category corresponding to "urgent" belongs to the set of categories having the highest priority. The category corresponding to "high priority access" may belong to the set of categories having the highest priority. High priority access means mobile communication operator-specific or public-duty specific access such as police and firefighter-specific access. It corresponds to Access Classes (AC) 11 to 15 of the conventional LTE. All classes belonging to non-standardized access classes belong to the second set of high priority classes. All classes belonging to the standardized access class belong to the third set of high priority classes except for emergency and high priority access.

For example, the UE NAS maps the triggered access to a category, as shown below.

[ operation 1] the UE NAS determines whether a triggered access can be mapped to one of the following standardized access categories. The following categories have the highest priority.

-emergency of

High priority access (AC 11-15)

If there is no category to which the access can be mapped among the standardized access categories provided by the network, the procedure proceeds to operation 2.

[ operation 2] the UE NAS determines whether a triggered access can be mapped to one of the following non-standardized access categories. All non-standardized access categories have the second highest priority.

Application of

-UE type, user group

-service access type

-call type

-type of signalling

-slice (slice) type

Combinations of the above elements

If there is no category to which the access can be mapped among the non-standardized access categories provided by the network, the procedure proceeds to operation 3.

Operation 3 the ue NAS determines whether the triggered access can be mapped to one of the standardized access categories other than those considered in operation 1. All standardized access categories except those with the highest priority have the third highest priority. All accesses belong to at least one standardized access category.

Fig. 1F is a flow diagram illustrating UE NAS operation according to an embodiment of the present disclosure.

Referring to fig. 1F, at operation 1F-02, the UE NAS receives information on non-standardized access classes supportable in the network through NAS signaling or application layer signaling. The information includes information about the mapping between categories and elements. For example, the information may include information about a mapping between categories and applications.

At operation 1f-05, the UE NAS receives an access category list from the UE AS, which provides barring configuration information in the system information sent by the gNB. At operation 1f-10, the UE NAS triggers access. At operations 1f-15, the UE NAS determines whether the access can be mapped to one of the categories with the highest priority. The category with the highest priority includes categories corresponding to "emergency" or "high priority access". If it is determined that the access can be mapped to one of the categories having the highest priority, the UE NAS maps the access to the corresponding category at operation 1 f-20. If it is determined that the access cannot be mapped to one of the categories having the highest priority, at operation 1f-25, the UE NAS determines whether the access can be mapped to one of the non-standardized access category information received from the network at operation 1f-02 and the non-standardized access category included in the list provided by the gNB at operation 1 f-05. If it is determined that the access can be mapped to one of the non-standardized access categories, the UE NAS maps the access to the corresponding category at operation 1 f-30. If it is determined that the access cannot be mapped to one of the non-standardized access categories, the UE NAS maps the access to one of the standardized access categories at operations 1 f-35. At operation 1f-40, the UE NAS sends a service request message including the mapped category to the UE AS.

Examples 1 to 2

In embodiments 1-2, the UE NAS maps an access to a standardized access category and, additionally, to a non-standardized access category to which the access may be mapped. In the present disclosure, the service request sent by the UE NAS to the UE AS comprises information indicating a standardized access class, since the triggered access should be mapped to one standardized access class. At operation 1f-05, the UE AS does not provide a list of access categories. Thus, the operation of determining whether an access can be mapped to one of the non-standardized access categories at operation 1f-25 is not performed based on the non-standardized access categories included in the list. For example, the UE NAS determines whether a non-standardized access category exists based only on information about non-standardized access categories supportable by the network provided through NAS signaling or application layer signaling.

In embodiments 1-2, the UE NAS may send both standardized and non-standardized access categories to the UE AS. In this case, the UE AS selects one of the standardized access category and the non-standardized access category to use the barring configuration information corresponding to the selected access category. If barring configuration information associated with both the mapped standardized and non-standardized access categories is broadcast by the gNB, the UE NAS performs an access barring check with the barring configuration information corresponding to the non-standardized access category. If barring configuration information associated with a non-standardized access category is not broadcast by the gNB, the UE NAS performs an access barring check with the barring configuration information corresponding to the standardized access category. If neither the barring configuration information associated with the mapped standardized access category nor the barring configuration information associated with the mapped non-standardized access category is broadcast by the gNB, the UE NAS does not perform an access barring check on the access and assumes that the access is allowed. However, there is one exception. If the mapped standardized access category corresponds to "emergency" or "high priority access" with the highest priority, if barring configuration information on the category is broadcast by the gNB, and if the barring configuration information indicates that access is allowed, the mapped non-standardized access category provided with the mapped standardized access category is not taken into account. For example, access is allowed.

Fig. 1G is a signal flow diagram illustrating an access control procedure according to an embodiment of the present disclosure.

Referring to FIG. 1G, at operation 1G-25, the network 1G-20 sends information to the UE NAS 1G-10 about the non-standardized access classes it supports, either through NAS signaling or application layer signaling. The information includes a mapping between categories and elements. For example, the information may include information about a mapping between categories and applications. At operation 1g-30, the UE NAS triggers access. At operations 1g-35, the UE maps the access to a standardized access category. The UE maps an access to one of the non-standardized access categories to which the access may be mapped if the information received from the network includes information about the non-standardized access categories to which the access may be mapped. At operation 1g-45, the UE NAS sends a service request including the mapped class to the UE AS1 g-15. For example, at operation 1g-45, the UE NAS may inform the UE AS 1g-15 of only standardized access categories or both standardized and non-standardized access categories. At operations 1g-40, the gNB uses the system information to provide per-class barring configuration information to the UE. Not all categories are forced to provide prohibited configuration information.

UE AS 1g-15 determines whether to allow access according to predetermined rules.

Referring to operations 1g-50, if the mapped standardized access category is a category corresponding to "emergency" or "high priority access", if barring configuration information for the category is provided by the gNB, and if the barring configuration information indicates access permission, then access is assumed to be allowed.

Otherwise, if the barring configuration information of the mapped non-standardized access category is provided by the gNB, the UE AS 1g-15 determines whether to allow access based on the corresponding barring information.

If the access does not correspond to either "emergency" or "high priority access" and if barring configuration information for the mapped standardized access category is provided by the gNB for accesses that are not mapped to any non-standardized access category, the UE AS 1g-15 applies the barring configuration information to determine whether to allow the access.

UE AS 1g-15 determines whether access is allowed and, if so, sends a connection request message to the gNB at operation 1 g-55.

Fig. 1H is a flowchart illustrating a UE NAS operation according to embodiment 2 of the present disclosure.

Referring to fig. 1H, at operation 1H-05, the UE NAS receives information about non-standardized access classes supportable in the network, which is provided through NAS signaling or application layer signaling. The information includes information about the mapping between categories and elements. For example, the information may include information about a mapping between categories and applications.

At operation 1h-10, the UE NAS triggers access. At operations 1h-15, the UE NAS maps the access to one of the standardized access categories. At operation 1h-20, the UE NAS maps access to non-standardized access categories, if possible. If there is no category to which the access may be mapped among the non-standardized access categories notified at operation 1h-05, the non-standardized access category may not be notified to the UE AS. At operation 1h-25, the UE NAS informs the UE of the category of AS mapping.

Fig. 1I is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure.

Referring to FIG. 1I, the UE includes Radio Frequency (RF) processors 1i-10, baseband processors 1i-20, memory units 1i-30, and controllers 1i-40.

The RF processors 1i-10 have functions of transmitting/receiving signals through radio channels, such as band conversion and amplification of the signals. For example, the RF processors 1i-10 up-convert baseband signals from the baseband processors 1i-20 into RF band signals, and transmit the RF signals via an antenna, and down-convert RF signals received via the antenna into baseband signals. For example, the RF processors 1i-10 may include transmit filters, receive filters, amplifiers, mixers, oscillators, digital-to-Analog converters (DACs), and Analog-to-Digital converters (ADCs). Although one antenna is depicted in the drawing, the UE may be equipped with multiple antennas. The RF processors 1i-10 may also include multiple RF chains. The RF processors 1i-10 may perform beamforming. For beamforming, the RF processors 1i-10 may adjust the phase and magnitude of signals to be transmitted/received in phase and magnitude through antennas or antenna elements. The RF processor 1 i-1-may be configured to support a Multiple Input Multiple Output (MIMO) scheme by which the UE can simultaneously receive a plurality of layers.

The baseband processors 1i-20 have a baseband signal-to-bit string conversion function according to the physical layer standard of the system. For example, in the data transmission mode, the baseband processors 1i-20 perform coding and modulation on a transmission bit string to generate complex symbols. In the data reception mode, the baseband processors 1i-20 perform demodulation and decoding on the baseband signals from the RF processors 1i-10 to recover the transmitted bit strings. In the case of using the OFDM scheme for data transmission, the baseband processors 1i-20 perform coding and modulation on a transmission bit string to generate complex symbols, map the complex symbols to subcarriers, perform Inverse Fast Fourier Transform (IFFT) on the symbols, and insert a Cyclic Prefix (CP) into the symbols to generate OFDM symbols. In the data reception mode, the baseband processors 1i to 20 divide the baseband signals from the RF processors 1i to 10 into OFDM symbols, perform Fast Fourier Transform (FFT) on the OFDM symbols to restore the signals mapped to the subcarriers, and perform demodulation and decoding on the signals to restore the transmitted bit strings.

The baseband processors 1i-20 and the RF processors 1i-10 process the transmission and reception signals as described above. The baseband processors 1i-20 and the RF processors 1i-10 may thus be referred to as transmitters, receivers, transceivers or communication units. At least one of the baseband processors 1i-20 and the RF processors 1i-10 may include a plurality of communication modules for supporting different radio access technologies. At least one of the baseband processors 1i-20 and the RF processors 1i-10 may further include a plurality of communication modules for processing signals in different frequency bands. For example, different radio access technologies may include Wireless Local Area Networks (WLANs) (e.g., institute of Electrical and Electronics Engineers (IEEE) 802.11) and cellular networks (e.g., LTE). The different frequency bands may include a Super High Frequency (SHF) band (e.g., 2.5GHz and 5GHz bands) and an mmWave band (e.g., 60 GHz).

The storage units 1i to 30 store data such as basic programs for operating the UE, application programs, and setting information. The storage units 1i-30 may also store information about a second access node for radio communication using a second radio access technology. The storage units 1i-30 provide stored information in response to a request from the controllers 1i-40.

The controller 1i-40 includes a multi-connection processor 1i-42 and controls the overall operation of the UE. For example, the controllers 1i-40 control the baseband processors 1i-20 and the RF processors 1i-10 to transmit and receive signals. The controllers 1i-40 write data to the memory cells 1i-30 and read data from the memory cells 1 i-30. To this end, the controllers 1i-40 may include at least one processor. For example, the controllers 1i-40 may include a Communication Processor (CP) for controlling Communication and an Application Processor (AP) for controlling higher-layer programs such as applications.

Fig. 1J is a block diagram illustrating a configuration of a new radio Node B (gNB) according to an embodiment of the present disclosure.

Referring to fig. 1j, the gnb includes RF processors 1j-10, baseband processors 1j-20, backhaul communication units 1j-30, storage units 1j-40, and controllers 1j-50.

The RF processors 1j-10 have functions of transmitting/receiving signals through radio channels, such as band conversion and amplification of the signals. For example, the RF processors 1j-10 up-convert baseband signals from the baseband processors 1j-20 into RF band signals, and transmit the RF signals via an antenna, and down-convert RF signals received via the antenna into baseband signals. For example, the RF processors 1j-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC. Although one antenna is depicted in the drawing, the gNB may be equipped with multiple antennas. The RF processors 1j-10 may also include multiple RF chains. The RF processors 1i-10 may perform beamforming. For beamforming, the RF processors 1j-10 may adjust the phase and magnitude of signals to be transmitted/received through antennas or antenna elements. The RF processors 1j-10 may be configured to transmit one or more layers of downlink MIMO operation.

The baseband processors 1j-20 have a baseband signal-bit string conversion function according to the physical layer standard of the system. For example, in the data transmission mode, the baseband processors 1j to 20 perform coding and modulation on a transmission bit string to generate complex symbols. In the data reception mode, the baseband processor 1j-20 performs demodulation and decoding on the baseband signal from the RF processor 1j-10 to recover the transmitted bit string. In the case of using the OFDM scheme for data transmission, the baseband processors 1j-20 perform coding and modulation on a transmission bit string to generate complex symbols, map the complex symbols to subcarriers, perform inverse IFFT on the symbols, and insert CPs into the symbols to generate OFDM symbols. In the data reception mode, the baseband processor 1j-20 divides the baseband signal from the RF processor 1j-10 into OFDM symbols, performs FFT on the OFDM symbols to recover the signal mapped to the subcarriers, and performs demodulation and decoding on the signal to recover the transmitted bit string. The baseband processors 1j-20 and the RF processors 1j-10 process the transmission and reception signals as described above. Thus, the baseband processors 1j-20 and the RF processors 1j-10 may be referred to as transmitters, receivers, transceivers or communication units.

The backhaul communication units 1j-30 provide interfaces for communicating with other nodes in the network. For example, the backhaul communication units 1j-30 convert a bit string to be transmitted from the gNB to another node (e.g., another gNB and a core network) into a physical signal, and convert a physical signal received from another node into a bit string.

The storage units 1j-40 store data such as basic programs, application programs, and setting information for the gNB operation. The memory unit 1j-40 may also store information about bearers established for the UE and measurement results reported by the connected UE. The memory units 1j-40 may also store information for use by the UE in determining whether to enable or disable the multi-connection. The memory units 1j-40 may provide stored data with reference to requests from the controllers 1j-50.

The controllers 1j-50 include multi-connection processors 1j-52 and control the overall operation of the gNB. For example, the controllers 1j-50 control the baseband processors 1j-20, the RF processors 1j-10, and the backhaul communication units 1j-30 for transmitting and receiving signals. The controllers 1j-50 read and write data to the memory cells 1 j-40. To this end, the controllers 1j-50 may include at least one processor.

Example 2

Fig. 2A is a signal flow diagram illustrating an access control procedure according to an embodiment of the present disclosure.

Referring to figure 2A, at operation 2A-25 the network 2A-20 sends information to the UE NAS 2A-10 about the non-standardized access categories it supports, either by NAS signaling or application layer signaling. The information includes a mapping between categories and elements. For example, the information may include information about a mapping between categories and applications. At operations 2a-30, the UE maps an establishment cause value corresponding to the access to an access category. The establishment cause value is included in an initial message sent to the gNB for the connection request and used by the gNB to make the access barring determination. At operations 2a-50, the gNB sends per-class barring configuration information to the UE via system information. Not all categories are forced to provide prohibited configuration information.

At operation 2a-35, the UE NAS informs the UE AS 2a-15 of the access category mapped to the determined establishment cause value.

At operation 2a-40, the UE AS 2a-15 determines whether to allow access according to predetermined rules.

If it is determined that access is allowed, UE AS 2a-15 sends a connection request message to the gNB at operation 2 a-45.

In the present disclosure, the establishment cause values are mapped one-to-one to standardized access categories. The standardized access class is used for access barring. The standardized access categories include at least one category corresponding to "emergency" and "high priority access", and each category is used to indicate an establishment cause value. In the present disclosure, the connection request message may include standardized access category information (index value) instead of the establishment cause value. In the conventional LTE technology, the following establishment cause values are used.

-emergency (emergency),

high priority access,

-mt-Access，

-mo-Signalling，

-mo-Data，

-delayTolerantAccess，

-mo-VoiceCall

according to an embodiment of the present disclosure, the establishment cause value has a standardized access category corresponding thereto, as follows:

-authentication (Access Category) 0),

-highPriortyAccess (Access class 1),

-mt-Access (Access class 2),

mo-Signalling (access category 3),

mo-Data (access category 4),

delayTolerantAccess (access category 5),

mo-VoiceCall (Access category 6)

Example 2-1

In embodiment 2-1, the UE NAS informs the UE AS 2a-15 of both the mapped non-standardized access class and standardized access class if there are any non-standardized access classes to which access can be mapped.

Fig. 2B is a flowchart illustrating a UE NAS operation according to embodiment 2-1 of the present disclosure.

Referring to fig. 2B, at operation 2B-05, the UE NAS receives information about non-standardized access classes supportable in the network, the information being provided through NAS signaling or application layer signaling. At operation 2b-10, the UE NAS triggers access. At operation 2b-15, the UE NAS maps the access to a standardized access class. At operation 2b-20, the UE NAS determines whether the access can be mapped to a non-standardized access category. If an access can be mapped to a non-standardized access category, the category corresponding to the access should be included in the non-standardized access category notified at operation 2 b-05. If there is a non-standardized access category to which the access can be mapped, the UE NAS sends a service request including both the mapped standardized and non-standardized access categories to the UE AS at operation 2 b-25. If there is no non-standardized access category to which the access can be mapped, the UE NAS sends a service request including only the mapped standardized access category to the UE AS at operation 2 b-30. If the standardized access categories are sent to the UE AS, this is the same meaning AS the establishment cause values are sent to the UE AS, since the standardized access categories are mapped one-to-one to the establishment cause values.

Fig. 2C is a flowchart illustrating a UE AS operation according to embodiment 2-1 of the present disclosure.

Referring to fig. 2C, at operation 2C-05, the UE AS receives a service request from the UE NAS and determines whether the service request includes a standardized access category (or an establishment cause value) or both a standardized access category and a non-standardized access category. If it is determined that the service request includes only the standardized access category, at operation 2c-10 the UE AS determines whether to allow access to the requested service based only on barring configuration information corresponding to the standardized access category. If it is determined that access is to be allowed, the UE AS sends an RRC Connection Request (Connection Request) message to the gNB. The UE AS assumes access is allowed if barring configuration information corresponding to the standardised access class is not included in the system information broadcast by the gNB. At operation 2c-15, the UE AS includes a standardized access class value (index value) or an establishment cause value corresponding to a standardized access class in the RRC connection request message sent to the gNB. If it is determined that the service request includes both a standardized access category and a non-standardized access category, at operation 2c-20 the UE AS determines whether to first allow access to the requested service based on barring configuration information corresponding to the non-standardized access category. If barring configuration information corresponding to the non-standardized access category is not included in the system information broadcast by the gNB, the UE AS determines whether access is to be allowed based on the barring configuration information corresponding to the standardized access category. The UE AS assumes access is allowed if neither barring configuration information corresponding to the non-standardized access category nor barring configuration information corresponding to the standardized access category is included in the system information broadcast by the gNB. At operation 2c-25, the UE AS includes a standardized class value (index value) or an establishment cause value corresponding to the standardized access class in the RRC connection request message sent to the gNB.

Examples 2 to 2

In embodiment 2-2, the UE NAS only informs the UE AS of any non-standardized access category to which an access can be mapped, if any.

Fig. 2D is a flowchart illustrating a UE NAS operation according to embodiment 2-2 of the present disclosure.

Referring to fig. 2D, at operation 2D-05, the UE NAS receives information on non-standardized access classes supportable in the network, the information being provided through NAS signaling or application layer signaling. At operation 2d-10, the UE NAS triggers access. At operation 2d-15, the UE NAS maps the access to the standardized access class. At operation 2d-20, the UE NAS determines whether the access can be mapped to a non-standardized access category. If an access can be mapped to a non-standardized access category, the category corresponding to the access should be included in the non-standardized access category provided at operation 2 d-05. If there is a non-standardized access category to which the access can be mapped, the UE NAS sends a service request including the mapped non-standardized access category to the UE AS at operation 2 d-25. If there is no non-standardized access category to which the access can be mapped, the UE NAS sends a service request including the mapped standardized access category to the UE AS at operation 2 d-30. If the standardized access categories are sent to the UE AS, this is the same meaning AS the establishment cause values are sent to the UE AS, since the standardized access categories are mapped one-to-one to the establishment cause values.

Fig. 2E is a flowchart illustrating UE AS operation according to embodiment 2-2 of the present disclosure.

Referring to fig. 2E, at operation 2E-05, the UE AS receives a service request from the UE NAS and determines whether the service request includes a standardized access category (or an establishment cause value) or a non-standardized access category. If it is determined that the service request includes only the standardized access category, at operation 2e-10 the UE AS determines whether to allow access to the requested service based only on barring configuration information corresponding to the standardized access category. If it is determined that access is to be allowed, the UE AS sends an RRC connection request message to the gNB. The UE AS assumes access is allowed if barring configuration information corresponding to the standardized access category is not included in the system information broadcast by the gNB. At operation 2e-15, the UE AS includes a standardized access category value (index value) or an establishment cause value corresponding to the standardized access category in the RRC connection request message sent to the gNB. If it is determined that the service request includes only a non-standardized access category, at operation 2e-20 the UE AS determines whether to allow access to the requested service based on barring configuration information corresponding to the non-standardized access category. If barring configuration information corresponding to the non-standardized access category is not included in the system information broadcast by the gNB, the UE AS determines whether to allow access based on the barring configuration information corresponding to the standardized access category. At operation 2e-25, the UE AS has to autonomously determine the appropriate standardized access category based on the non-standardized access category, since the UE NAS does not inform any standardized access category. The UE AS assumes access is allowed if neither barring configuration information corresponding to the non-standardized access category nor barring configuration information corresponding to the standardized access category is included in the system information broadcast by the gNB. At operation 2c-30, the UE AS includes a standardized class value (index value) or an establishment cause value corresponding to the standardized access class in the RRC connection request message sent to the gNB.

Fig. 2F is a signal flow diagram for a network to provide various types of barring configuration information for access control to a UE in accordance with an embodiment of the present disclosure.

Referring to fig. 2F, at operation 2F-15, the gNB 2F-10 sends barring configuration information to the UE 2F-05 using system information. The present disclosure proposes a method for efficiently configuring prohibited configuration information. As described above, the barring configuration information may be provided per access category. Here, the barring configuration information corresponding to the access category of "emergency" has a BOOLEAN (BOOLEAN) format. For example, 1-bit information is used to indicate whether access to emergency services is allowed. The barring configuration information corresponding to the access category of "high priority access" has a BOOLEAN or bitmap format. "high priority access" means mobile communication carrier-specific or public-duty-specific access. In the case where there may be multiple types of dedicated links, a bitmap format is used to indicate whether each of the dedicated links is allowed access. For example, a 5-bit map may be used, where the first bit indicates whether a mobile communication operator-specific link is allowed to be accessed, and the second bit indicates whether a police-exclusive link is allowed to be accessed. The information carried by the predetermined bits of the bitmap may only be valid in a particular country or PLMN. For example, the first and last bits of the 5-bit map may be valid in the home PLMN/equivalent PLMN (HPLMN/EPLMN), while the second, third, and fourth bits of the 5-bit map may be valid in the home country. Bitmap information may be provided indicating whether each category is allowed to access the "high priority access" service. For example, bitmap information may be included in the per-class barring configuration information to indicate whether access to the "high priority access" service is allowed per class.

The barring configuration information corresponding to standardized and non-standardized access categories comprises an ac-BarringFactor IE and an ac-Barringtime IE. The value of the ac-BarringFactor alpha is within the range of more than or equal to 0 and less than or equal to 1. UE AS 1c-15 extracts random values of rand within the range of more than or equal to 0 and less than or equal to rand < 1; if the random value is less than ac-BarringFactor, then access is assumed not to be barred, and if not, then access is assumed to be barred. If it is determined that access is barred, the UE AS delays the access attempt by a duration derived by a predetermined equation. For example, the delay duration may be calculated according to the following equation.

“Tbarring”(0.7+0.6*rand)*ac-BarringTime。

In the present disclosure, if a mobile communication operator wants to allow 100% access to a service belonging to a specific standardized access category, all that is required is not to provide barring configuration information corresponding to the category.

A mobile communications operator may want to allow 100% access to services belonging to a particular non-standardized access category. However, although the barring configuration information corresponding to the standardized access category is not provided as in the case of the standardized access category, in the present disclosure, the access barring check is first performed with the barring configuration information corresponding to the standardized access category. Thus, it is difficult to allow access 100% as expected. Therefore, an indicator is needed that indicates whether 100% of the access associated with a particular non-standardized access category is allowed. The present disclosure proposes a 1-bit indicator indicating whether to skip the prohibition check for a category in the prohibition configuration information of the corresponding category.

In LTE Rel-11 EAB technology, barring configuration information for MTC devices is applicable to a specific group of UEs. Table 1 shows the relevant asn.1 taken from 3GPP ts36.331.

[ Table 1]

In table 1, EAB-Category indicates the Category of UE to which EAB is applicable. The value a corresponds to all UEs, the value b corresponds to UEs that are neither in their HPLMN nor in a PLMN equivalent to their HPLMN, and the value c corresponds to UEs that are neither in a PLMN of the most preferred PLMN of the country where the UE is roaming nor in their HPLMN nor in a PLMN equivalent to their HPLMN in the operator defined PLMN selector list on USIM, see TS22.011[10].

The eab-Category IE is used to indicate the group of three categories to which the barring configuration information is applied. In the next generation mobile communication system, the barring configuration information may be applied to each access category in a similar manner. In the present disclosure, the access category-specific barring configuration information comprises information indicating a group of UEs to which the configuration information applies. The UEs may be divided into three groups.

1) Group 1: all UE

2) Group 2: UEs that are neither in their HPLMN nor in their equivalent PLMN

3) Group 3: UEs that are listed in neither the PLMN of the most preferred PLMN of the country where the UE is roaming nor in their HPLMN nor in the PLMN equivalent to their HPLMN in the operator defined PLMN selector list on USIM

Example 3

Fig. 3A is a signal flow diagram illustrating a procedure for providing system information in a next generation mobile communication system.

Referring to fig. 3A, in a next generation mobile communication system, system information broadcast by the gnbs 3A-10 is divided into minimum System Information (SI) and other SIs. At operations 3a-15, the gNB 3a-10 periodically broadcasts a minimum SI that includes configuration information required for initial access and SI scheduling information required for the UE3a-05 to receive other SIs that are broadcast periodically or in response to a request. Typically, the other SI includes all configuration information not included in the minimum SI. Other SIs are periodically either broadcast in response to a request from the UE3a-05 at operation 3a-20 or sent to the UE3a-05 by dedicated signaling at operation 3 a-25. In case that other SI is sent in response to a request from the UE3a-05, the UE3a-05 needs to determine whether the other SI is valid in the serving cell or is being broadcast (in response to a request from another UE). Such determination may be made based on specific information included in the minimum SI. A UE in IDLE mode (RRC IDLE) or INACTIVE mode (RRC INACTIVE) may request other SIs without RRC state transition. The UE in CONNECTED mode (RRC _ CONNECTED) may request and receive other SI through dedicated RRC signaling. Other SIs are broadcast at predetermined intervals during a time period. Public Warning System (PWS) information is provided as part of other SIs. Whether other SIs are broadcast or sent to the UE by RRC signaling depends on the network implementation.

Fig. 3B is a signal flow diagram illustrating a random access procedure in a conventional LTE system.

Referring to fig. 3B, random access is performed to achieve uplink synchronization and to transmit data to a network. Random access may be performed for mode transition from idle mode to connected mode, RRC reestablishment, handover, and uplink/downlink data transmission. If the UE 3b-05 receives the dedicated preamble from the gNB 3b-10, it performs a random access procedure by transmitting the dedicated preamble to the gNB 3 b-10. Otherwise, UE 3b-05 selects one of the two preamble groups and then randomly selects a preamble from the selected group. These two groups are called group a and lease B. If the channel quality status is greater than the threshold, and if the size of msg3 is greater than the threshold, then UE 3b-05 selects a preamble from group A; if these conditions are not met, the UE 3B-05 selects a preamble from group B. At operation 3b-15, the UE 3b-05 transmits the selected preamble in the nth subframe. If the preamble is transmitted in the nth subframe, a Random Access Response (RAR) window starts from the n +3 th subframe, so that at operation 3b-20, the UE 3b-05 monitors the RAR window to receive RARs. The RAR scheduling information may be indicated by a Random Access Radio Network Temporary Identifier (RA-RNTI) of a Physical Downlink Control Channel (PDCCH). The RA-RNTI is derived based on the radio resource location in the time-frequency domain for preamble transmission. The RAR includes a Timing Advance Command (Timing Advance Command), a UL grant, and a temporary cell RNTI (cell RNTI, C-RNTI). If the RAR is successfully received within the RAR window, at operation 3b-25, UE 3b-05 transmits msg3 based on information contained in the UL grant included in the RAR. msg3 includes different information depending on the purpose of random access. Table 2 illustrates information that may be included in msg3.

[ Table 2]

If RAR is received in the nth subframe, then UE 3b-05 sends msg3 in the (n + 6) th subframe. A Hybrid Automatic Repeat Request (HARQ) process starts from msg3. Upon transmitting msg3, the UE 3b-05 starts a predetermined timer and monitors to receive a Contention Resolution (CR) message at operation 3b-30 until the timer expires. The CR message may include an RRC connection setup or RRC connection reestablishment message, in addition to a CR Media Access Control (MAC) Control Element (CE), depending on the purpose of random Access.

Fig. 3C is a flowchart illustrating a procedure for selecting one of a System Information (SI) request method based on msg1 and a SI request message based on msg3 according to an embodiment of the present disclosure.

Referring to fig. 3C, in order to request other SIs, the UE performs a random access procedure. The UE may request the required system information from the network using msg1 (preamble) or msg3. At operation 3c-05, the UE determines whether a minimum SI periodically broadcast by the gNB includes information on Physical Random Access Channel (PRACH) resources for requesting the SI. The PRACH resource information may include a preamble ID (index) for requesting the SI and information on radio resources for transmitting the preamble. If it is determined that the minimum SI includes PRACH resource information, the UE may request other SIs using msg1 dedicated to SI request at operation 3 c-10. If it is determined that the minimum SI does not include PRACH resource information, the UE may request other SIs using msg3 at operation 3 c-15. To request SI, a new RRC message is defined.

Example 3-1

In embodiment 3-1, if a service Request is triggered before a predetermined time point during a random access procedure in which a UE requests system information from a gNB, the UE transmits an RRC Connection Request or RRC Connection Resume Request (Connection Resume Request) message indicating the system information, the RRC Connection Request or RRC Connection Resume Request message being for the service Request. In this case, it is not necessary to define a new RRC message for the system information request.

Fig. 3D is a signal flow diagram illustrating a service request processing procedure in a process of requesting system information according to embodiment 3-1 of the present disclosure.

Referring to fig. 3D, at operation 3D-15, the UE 3D-05 receives system information from the gNB 3D-10. The system information may include random access configuration information required for an SI request based on msg 1. If the system information does not include the random access configuration information required for msg1 based SI requests, then at operation 3d-20, the UE 3d-05 triggers an msg3 based SI request. At operation 3d-25, the UE 3d-05 triggers a random access procedure for SI request purposes by sending a preamble. At operation 3d-30, UE 3d-05 receives RAR from gNB 1d-10 and at operation 3d-45 sends an RRC message to gNB 3d-10 using msg3, the RRC message being newly defined for SI request. At operation 3d-35, during the random access procedure, the UE 3d-05 may trigger a service request before sending msg3. The service request may be triggered by the UE NAS in IDLE (IDLE) mode or by the UE AS in INACTIVE (INACTIVE) mode. At operation 3d-40, the UE sends msg3 carrying an RRC connection request message in idle mode or an RRC connection recovery request message in inactive mode, instead of a new RRC message defined for the system information request, which includes an indicator indicating the requested system information (i.e., SI message or SIB).

If the gNB 3d-10 receives the RRC connection request message from the UE 3d-05, it generates an msg4 including the UE CR identity MAC CE and the RRC connection setup message at operation 3 d-50.

If the gNB 3d-10 receives the RRC connection resume request message from the UE 3d-05, it generates an msg4 including the UE CR identity MAC CE and the RRC connection resume message at operation 3 d-50.

If the gNB 3d-10 receives a new RRC message from the UE 3d-05 defined for the system information request, it generates an msg4 including the UE CR identity MAC CE at operation 3 d-50.

At operation 3d-55, gNB 3d-10 sends msg4 to UE 3d-05.

If the gNB 3d-10 receives one of the new RRC messages defined for the SI request from the UE 3d-05, an RRC connection request or an RRC connection resume request message including an indicator indicating the requested system information, the gNB 3d-10 transmits the system information indicated by the indicator to the UE 3d-05 on a scheduled basis. Scheduling information is provided to the gNB 3d-10 via the minimum SI advance.

In the case of a service request triggered after msg3 carrying a system information request message is sent, the UE 3d-05 triggers a separate random access procedure for handling the access corresponding to the service request. If a random access procedure for a service request is ongoing, the UE 3d-05 can request system information by sending msg3 carrying an RRC connection request message in idle mode or an RRC connection resume request message in inactive mode, the RRC message including an indicator indicating that system information (i.e., SI message or SIB) is requested.

Examples 3 to 2

In embodiment 3-2, if a service request is triggered before a predetermined point during a random access procedure in which a UE requests system information from a gNB, the UE preferentially processes the service request. Generally, configuration information required for an access network is included in the minimum SI. Therefore, it is possible to perform a random access procedure without requesting other SI as described above. Further, in view of the user, it is preferable to preferentially process the service request rather than the system information acquisition. Although a random access procedure is performed to request system information, msg3 carries an RRC connection request or RRC connection recovery request message for service request. The UE suspends the system information request and resumes the system information request if the service request is fully processed.

Fig. 3E is a signal flow diagram illustrating a procedure of processing a service request in a procedure of requesting system information according to embodiment 3-2 of the present disclosure.

Referring to FIG. 3E, at operation 3E-15, the UE 3E-05 receives system information from the gNB 3E-10. The system information may include random access configuration information required for an SI request based on msg 1. If the system information does not include the random access configuration information required for the msg1 based SI request, then at operation 3e-20 the UE 3e-05 triggers the msg3 based SI request. At operation 3e-25, the UE 3e-05 triggers a random access procedure for SI request purposes by sending a preamble. At operation 3e-30, UE 3e-05 receives RAR from gNB 1 e-10. UE 3e-05 sends an RRC message including an indicator indicating the requested SI to gNB 3e-10 via msg3 based on the UL grant included in the RAR. During the random access procedure, the UE 3e-05 may trigger a service request before sending msg3. At operations 3e-35, the service request may be triggered by the UE NAS in idle mode or by the UE AS in inactive mode. At operation 3e-40, the UE sends msg3 carrying an RRC connection request message in idle mode or an RRC connection resume request message in inactive mode, instead of a new RRC message defined for the system information request.

If the gNB 3e-10 receives the RRC connection request message from the UE 3e-05, it generates an msg4 including the UE CR identity MAC CE and the RRC connection setup message.

If the gNB 3e-10 receives the RRC connection resume request message from the UE 3e-05, it generates an msg4 including the UE CR identity MAC CE and the RRC connection resume message.

At operation 3d-45, gNB 3e-10 sends msg4 to UE 3e-05.

In the case of a service request triggered after msg3 carrying a system information request message is sent, the UE 3e-05 triggers a separate random access procedure for handling the access corresponding to the service request. If the random access procedure of the service request is ongoing, the UE 3e-05 does not request system information.

According to another embodiment of the present disclosure, the gNB may transmit configuration information to the UE such that when a service request is triggered before a predetermined point of time during a random access procedure in which the UE requests system information from the gNB, the UE selects one of the system information request and the service request to be preferentially processed. To achieve this, the gNB may configure a 1-bit indicator indicating a request to be processed preferentially in the minimum SI.

Fourth embodiment

A detailed description of well-known functions and configurations incorporated herein may be omitted to avoid obscuring the subject matter of the present disclosure. Embodiments of the present disclosure are described with reference to the drawings.

Fig. 4A is a diagram illustrating an architecture of a next generation mobile communication system according to an embodiment of the present disclosure.

Referring to fig. 4A, the radio access network of the next generation mobile communication system includes a new radio Node B (gNB) 4A-10 and a new radio core network (AMF) 4A-05. The new radio user equipment (hereinafter NR UE or simply UE) 4a-15 is connected to the external network via the gNB 4a-10 and AMF 4a-05.

In fig. 4A, the gnbs 4A-10 correspond to evolved Node bs (enbs) in a conventional LTE system. The NR UEs 4a-15 are connected to a gNB which may provide better service than a legacy eNB. In a next generation mobile communication system in which all user traffic is served through a shared channel, an entity is required to collect UE-specific status information (such as buffer status, power headroom status, and channel status) and schedule UEs based on the collected information, and the gnbs 4a-10 are responsible for these functions. Typically, one gNB carries multiple cells. In order to satisfy the higher data rate requirement than the conventional LTE, it is necessary to secure the maximum bandwidth wider than ever by employing advanced techniques such as Orthogonal Frequency Division Multiplexing (OFDM) as a radio access scheme and beamforming. Adaptive Modulation and Coding (AMC) techniques may be employed to determine the modulation scheme and channel coding rate to adapt to the channel conditions of the UE. The AMF 4a-05 is responsible for mobility management, bearer establishment and QoS establishment. The AMFs 4a-05 are responsible for other control functions as well as UE mobility management functions related to multiple gnbs. The next generation mobile communication system may interoperate with a conventional LTE system in such a manner that the AMF 4a-05 is connected to a Mobility Management Entity (MME) 4a-25 through a network interface. The MME 4a-25 is connected to the eNBs 4a-30, which are legacy base stations. A UE supporting LTE-NR dual connectivity may establish a connection to enbs 4a-30, as indicated by reference numerals 4a-35, and to a gNB 4a-10, as indicated by reference numerals 4 a-20.

Fig. 4B is a diagram illustrating a method for determining whether to accept access in a legacy LTE system according to an embodiment of the present disclosure.

Referring to fig. 4A, generally, the functionality of an LTE UE is divided into an Access Stratum (AS) 4b-15 and a NAS 4b-05. The AS is responsible for all access related functions and the NAS 4b-05 is responsible for non-access related functions such AS Public Land Mobile Network (PLMN) selection and service requests. The accessibility determination may be primarily determined by the UE AS. As mentioned above, a network in congestion may restrict new accesses and for this purpose it broadcasts relevant configuration information for each UE to make its own access determination, as indicated by reference numerals 4 b-35. With the introduction of new requirements in legacy LTE systems, new barring mechanisms have been proposed, which as a result allow multiple access barring checks. If the UE NAS layer issues a service request, AS indicated by reference numeral 4b-10, the UE AS checks if the UE can actually access the network. If the establishment cause value of the service request is "delay tolerant access", the UE AS first performs Extended Access Barring (EAB), AS indicated by reference numerals 4 b-20. The EAB barring mechanism is performed as an access check procedure applicable only to Machine Type Communication (MTC). If the EAB check is passed, the UE AS performs dedicated congestion control for data communication (ACDC), AS indicated by reference numerals 4 b-20. The application requesting the service is assigned an ACDC category whose value may be included in the service request transmitted to the UE AS, AS indicated by reference numerals 4 b-55. The network may provide prohibited configuration information for each ACDC category. Thus, the access checking procedure may be performed per group, which groups are classified by ACDC category. If the barring configuration information for each ACDC category is not provided by the network, the UE AS omits the ACDC access checking procedure. If the ACDC check is passed, the UE AS performs Access Class Barring (ACB), AS indicated by reference numerals 4 b-30. The ACB is an access check procedure using barring configuration information separately provided according to Mobile Originating (MO) data or MO signaling. For multi-way telephony (MMTEL) voice/video/SMS services, the ACB procedure may be omitted using an ACB skip indicator, as shown at reference numerals 4 b-25. The UE AS may attempt to access the network if all of the above access checking procedures are passed. For example, the UE AS performs random access and transmits a Radio Resource Control (RRC) connection request message to the eNB, AS indicated by reference numerals 4 b-40. There may be another access check procedure that is not performed by the UE AS. If barring configuration information (SSAC) for MMTEL voice/video is received from the network, AS indicated by reference numerals 4b-45, the UE AS passes this information to the IMS layer responsible for managing the services in the UE, AS indicated by reference numerals 4 b-50. After receiving the barring configuration information, the IMS layer may perform an access check procedure when the service is triggered. SSAC, when introduced, is designed to cause the UE AS to perform a corresponding function regardless of the type of application or service. Therefore, in order to control the determination as to whether to accept access to a specific service (such as MMTEL voice/video), it is necessary to directly transfer the barring configuration information to a layer managing the service so that the corresponding layer performs an access check procedure.

Fig. 4C is a diagram illustrating a process for performing ACDC operation in a legacy LTE system, according to an embodiment of the present disclosure.

Referring to fig. 4C, in a conventional LTE system, ACDC has been proposed to make an accessibility determination for each application (service). Each application is assigned at least one ACDC category value. ACDC category values are selected in the range of 1 to 16. At operation 4c-25, the network 4c-20 provides the ACDC category information per application to the UE NAS 4c-10 using NAS messages. At operation 4c-50, network 4c-20 provides the UE AS 4c-15 with barring configuration information to be applied to each ACDC category using System information Block 2 (SIB 2). The barring configuration information includes an ac-BarringFactor Information Element (IE) and an ac-Barringtime IE. The value of the ac-BarringFactor alpha is within the range of more than or equal to 0 and less than or equal to 1. UE AS 4c-15 extracts random values of rand within the range of more than or equal to 0 and less than or equal to rand < 1; if the random value is less than ac-BarringFactor, then access is assumed not to be barred, and if not, then access is assumed to be barred. If it is determined that access is barred, the UE AS 4c-15 delays the access attempt for a duration based on the following equation.

"Tbarring" (0.7 +0.6 + rand). Ac-BarringTime. Equation 2

If a service request is triggered, at operation 4c-30, the UE AS 4c-15 extracts the ACDC category value for the application corresponding to the service. At operation 4c-35, the UE NAS 4c-10 sends a service request including the ACDC class value to the UE AS 4 c-15. Upon receiving the service request, at operation 4c-40, the UE AS 4c-15 determines whether access is accepted according to the ACDC category value based on ACDC barring configuration information included in SIB 2. If SIB2 does not include the barring configuration information corresponding to the ACDC category, then it is assumed that applications belonging to the ACDC category are allowed access during ACDC. If access is allowed by the access barring check procedure, the UE AS 4c-15 sends an RRC connection request for random access to the network at operation 4 c-45.

Fig. 4D is a diagram illustrating a structure of ACDC configuration information used in a conventional LTE system according to an embodiment of the present disclosure.

Referring to fig. 4d, ACDC configuration information (ACDC-BarringForCommon-r 13) 4d-10 may provide PLMN-specific forbidden configuration information sets (ACDC-BarringPerPLMN 1, ACDC-BarringPerPLMN 2.) -4 d-35 and 4d-40. If all PLMNs have the same barring configuration information set, one barring configuration information set (ACDC-BarringForCommon-r 13) 4d-05 may be set most widely. The PLMN-specific barring configuration information or the set of common barring configuration information comprises category-specific barring configuration information 4d-20, 4d-25 and 4d-30. As described above, the disabling configuration information 4d-45 includes the ac-BarringFactor IE and the ac-Barringtime IE. If there is no barring configuration information for a particular ACDC category, it is assumed that applications belonging to the corresponding ACDC category are not barred by the ACDC.

Fig. 4E is a diagram illustrating a procedure of a UE access control operation according to an embodiment of the present disclosure.

Referring to fig. 4E, the present disclosure proposes a method of controlling access based on access identification and access category as in a conventional ACDC. The access identity is an indication information defined in the 3GPP standard, i.e. specified explicitly in the standard document. The access identity is used to indicate one of several access types, as shown in the following table. It mainly indicates access types classified into access classes 11 to 15 and Multimedia Priority Services (MPS) and dedicated services (Mission Critical services (MCS)) having high priorities. The access classes 11 to 15 indicate operator private or public purpose access.

The access categories are divided into two categories. One of these two categories is the standardized access category. The category is defined at the RAN level, i.e. is explicitly classified in standard documents. Thus, the same standardized access category is applicable to different operators. In the present disclosure, the emergency related category belongs to the standard access category. Each access belongs to at least one standardized access category. The other is a non-standardized access category. This category is defined outside of the third generation partnership project (3 GPP) architecture and is therefore not explicitly classified in standard documents. Thus, operators have their own operator-specific access categories that have different meanings. This is the same characteristic of the categories in a traditional ACDC. However, a particular access triggered by the UE NAS may not be mapped to a non-standardized access category. The proposed access control scheme differs from conventional ACDC in that the classification is made with other elements and applications, such as service access type, call type, UE class, user group, signaling type, slice type and any combination thereof. For example, access control may be performed for certain element-specific access types. The above access categories are used to indicate specific accesses, as shown in the following table. Access classes 0 to 7 are used to indicate standardized access classes and access classes 32 to 63 are used to indicate operator specific access classes.

The operator's server 4e-25 provides operator specific access category information MO to the UE NAS1e-10 via NAS signaling or application layer data transmission. The above information indicates a certain element, such as an application, corresponding thereto. For example, the above information may explicitly indicate that the access category 32 corresponds to Facebook (Facebook) application access. The gNB 4e-20 uses the system information to provide the UE with a list of categories containing barring configuration information and per-category barring configuration information. The UE 4e-05 includes the logical blocks of NAS 4e-10 and AS 4 e-15. The UE NAS maps the triggered access to one or more access identities and one access category according to predetermined rules. Alternatively, the access may be mapped to a standardized access category and, additionally, to an operator specific access category. The UE NAS 4e-10 sends the mapped access identity and access category and the service request to the UE AS 4 e-10. The UE AS 4e-15 determines whether to allow the access triggered by the UE NAS 4e-10 based on the barring configuration information (barring check).

Providing the access identity and the access category may be considered to be associated with an establishment cause. In LTE, the UE NAS provides the establishment cause information to the UE AS, and the UE sends an RRC connection request message including the establishment cause information to the network. The network determines whether to accept or reject the RRC connection request based on the establishment cause information. The conventional setup cause information configuration is shown in table 3.

[ Table 3]

The cause value may be replaced by an access identity and a standardized access category. For example, in the establishment cause information, highloadyacess may be replaced by Access identity, emergency may be replaced by Standardized Access Category (Standardized Access Category) 2, mt-Access may be replaced by Standardized Access Category 0, mo-Signalling may be replaced by Standardized Access Category 3, mo-Data may be replaced by Standardized Access Category 7, delayTolerantAccess may be replaced by Standardized Access Category 1, and mo-icevocall may be replaced by Standardized Access Category 4. If the access attempt is mapped to an access identity and a standardized access category, there is no need to provide establishment cause information and a service request. However, if the access attempt is mapped to an operator specific access category instead of a standardized access category, there is still a need to provide establishment cause information. In the present disclosure, three options are presented.

In option 1, the access attempt is always mapped to a standard access category and, if available, to an operator specific access category. In this case, the UE NAS does not provide the establishment cause information to the UE AS. The UE AS includes an establishment cause value corresponding to the access identity or standardized access category information in the (alternative) RRC connection request message. It is also possible to include the access identity or the standardized access class value in the RRC connection request message without replacement.

In option 2, the access attempt is mapped to an access category, regardless of whether the access category is a standardized access category or an operator specific access category. The UE NAS may selectively provide establishment cause information to the UE AS depending on whether the access attempt is mapped to a standardized access category. For example, if the access attempt is mapped to a standardized access category, the UE NAS does not provide the establishment cause value to the UE AS; the UE NAS provides the establishment cause value to the UE AS if the access attempt is mapped to an operator specific access class instead of a standardized access class.

In option 3, the access attempt is mapped to an access category, regardless of whether the access category is a standardized access category or an operator specific access category. If the access attempt is mapped to an operator specific access category and not to any other access identity, the UE AS derives an establishment cause value from the operator specific access category according to a predetermined rule and includes the establishment cause value in the RRC connection request message. The predetermined rule is for example mo-Data corresponding to establishment cause information on all operator specific access categories.

If the access attempt is mapped to a standardized access category, the UE AS includes an establishment cause value corresponding to the access identity or standardized access category information in the (alternative) RRC connection request message. It is also possible to include the access identity or the standardized access class value in the RRC connection request message without replacement.

If the UE NAS provides the access identity in any of the options, the highprioritylaccess corresponding to the access identity is included as an establishment cause value in the RRC connection request message. It is also possible to include the access identity value in the RRC connection request message without replacement.

The operator may wish to allow access to a predetermined type of service corresponding to at least one of the access classes 11 to 15. The present disclosure is characterized by determining whether to allow access belonging to access classes 11, 12, 13, 14 and 15 depending on the identified attributes of the access class. To achieve this, the present disclosure provides a method for configuring barring configuration information of an access identity or access category. In the present disclosure, it is assumed that the access category-specific barring configuration information is configured with ac-barringFactor and ac-barringtime, as is the barring configuration information of the related art ACB or ACDC.

Fig. 4F is a signal flow diagram illustrating an access control procedure according to an embodiment of the present disclosure.

Referring to FIG. 4F, UE 4f-05 includes NAS 4f-10 and AS 4f-15. The NAS is responsible for operations not directly related to radio access, such AS authentication service requests and session management, while the AS 4f-15 is responsible for operations related to radio access. At operation 4f-25, the network 4f-20 provides the MOI to the NAS 4f-10 via OAM (application layer data message) or NAS message. The MOI indicates elements, such as applications, corresponding to each operator-specific access category. To identify the operator specific category to which the triggered access is mapped, the NAS 4f-10 uses MOI. If the service is triggered, the NAS maps an access identity corresponding to the attributes of the service to an access category at operation 4 f-30. Services may be mapped to no (none) or at least one access identity. Services may be mapped to access categories. Under the assumption that a service can be mapped to one access class, the NAS 4f-10 determines whether the service is mapped to an operator-specific access class provided in the MO. If the service is not mapped to any operator specific access category, the NAS 4f-10 maps the service to one of the available standardized access categories. The NAS 4f-10 maps services to operator specific access classes and standardized access classes under the assumption that services can be mapped to multiple access classes. However, the service is not mapped to any operator specific access category, and the NAS 4f-10 maps the service to one of the available standardized access categories. The mapping rule may be applied in addition to emergency services. At operation 4f-40, the NAS 4f-10 sends a service request including the mapped access identities and access categories to the AS 4f-15. At operation 4f-35, the AS 4f-15 receives barring configuration information included in the system information broadcast by the network 4 f-20. The prohibition configuration information is described below. At operation 4f-45, the AS determines whether the service request is accepted based on the access identity and access category information that the NAS has mapped to the service and corresponding mapping configuration information received from the network 4 f-20. If the service request is accepted according to the predetermined rules, the AS 4f-15 requests RRC connection establishment from the network 4f-20 at operation 4 f-50.

Fig. 4G is a diagram illustrating a method for configuring access barring configuration information according to an embodiment of the present disclosure.

Referring to fig. 4G, the present disclosure proposes a method for allowing a specific type of access among accesses corresponding to at least one of the access classes 11 to 15. For example, access belonging to access class 11 and attempting to make text and voice call services may be allowed.

In the first embodiment of the present disclosure, the network provides individual configuration information corresponding to each access identity in the form of a bitmap whose bits are mapped to predetermined services, as shown in part (a) of fig. 4G. The service may be classified as one of a text service, a voice call service, a video call service, and the like. In this embodiment of the disclosure, the bits are mapped to the service indicated by the access category. Here, the access category may be limited to a standardized access category. In this case, a bitmap including 8 bits is generated as the barring configuration information per access identity, since the number of the aforementioned standardized access categories is 8. Certain services corresponding to standardized access categories may be excluded when configuring the bitmap. For example, it may be assumed that a standardized access class number 0 corresponding to a Mobile Terminated (MT) service is always allowed to be accessed. Under this assumption, no bits in the bitmap are needed that map to such a service. If one of the bits constituting the bitmap is set to "0", this means that a service corresponding to the access category mapped to the corresponding bit is allowed to be accessed. If the corresponding bit is set to "1", this means that the corresponding service access is not allowed or an additional barring check is required to make the final decision on whether to allow access. The access attempt may be mapped to one or more access identities and in this case, if at least one of the bits corresponding to the multiple access identities is set to "0", it is assumed that the access attempt is allowed.

In a second embodiment of the present disclosure, the network may include information in the form of a bitmap including bits mapped to respective access identities in the barring configuration information for each access category, as shown in part (b) of fig. 4G. Assume that the barring configuration information per access category includes ac-barringFactor and ac-barringTime, as is the barring configuration information of a conventional ACB or ACDC. Since there are 7 active access identities in the table above, the bitmap consists of 7 bits. For example, in part (b) of fig. 4G, bit b0 corresponds to identification number 1, bit b1 corresponds to identification number 2, bit b2 corresponds to identification number 11, bit b3 corresponds to identification number 12, bit b4 corresponds to identification number 13, bit b5 corresponds to identification number 14, and bit b6 corresponds to identification number 15.

In a third embodiment of the present disclosure, the network provides separate configuration information corresponding to the first and second access identities in the form of a bitmap including bits mapped to predetermined services, as shown in part (c) of fig. 4G. This configuration information is used by the UE AS when the access attempt corresponds to the first or second access identity. The first and second access identities indicate a multimedia service (multimedia priority service (MPS)) and a dedicated service (task critical service (MCS)) having a priority, respectively. Whether to allow access to the service corresponding to the above-described access identity is determined depending on one of the following three types of the UE.

a) A UE configured for MPS (or MCS);

b) UEs configured for MPS (or MCS) and listed in an operator defined PLMN selector list as the most preferred PLMN for the country where the UE is roaming or in their HPLMN or equivalent PLMN to their HPLMN;

c) UEs configured for MPS (or MCS) and in their HPLMN or equivalent PLMN to their HPLMN.

Accordingly, the individual barring configuration information of the access identity is generated in the form of a bitmap including 3 bits corresponding to three types of UEs. Each bit indicates whether access of the corresponding UE is allowed. For example, in part (c) of fig. 4G, bit b0 corresponds to a UE configured for MPS (or MCS), bit b1 corresponds to a UE configured for MPS (or MCS) and listed in an operator-defined PLMN selector list as being in the PLMN of the most preferred PLMN of the country where the UE is roaming or in their HPLMN or in a PLMN equivalent to their HPLMN, and bit b2 corresponds to a UE configured for MPS (or MCS) and in their HPLMN or in a PLMN equivalent to their HPLMN. The UE knows which of the above types it belongs to.

The UE indicated by the bitmap information is allowed to access. However, the UE not indicated by the bitmap information is barred from access, or is tested whether it is finally allowed to access by a barring check with barring configuration information corresponding to the access category.

It may be assumed that UEs not indicated by the bitmap information are allowed to access. Meanwhile, the UE indicated by the bitmap information may be barred from access or tested whether it is finally allowed to access by a barring check with barring configuration information corresponding to an access category.

The separate barring configuration information corresponding to the access identity may comprise the configuration information proposed in the first and second embodiments. The configuration information proposed in the third embodiment is included in the configuration information of the first or second identifier. It is also possible that the barring configuration information corresponding to the access category in the second embodiment comprises the configuration information proposed in the third embodiment. Even in this case, the configuration information proposed in the third embodiment is applied only to the first or second access identities. In the case where the barring configuration information corresponding to the access category includes the configuration information proposed as the best solution in the third embodiment, the first and second identifiers have 3 bits corresponding thereto. Each bit is used to indicate the type of UE, as described in the third embodiment. Further, the access identity has 1 bit corresponding thereto.

Fig. 4H is a flowchart illustrating an operation of the UE NAS according to an embodiment of the present disclosure.

Referring to fig. 4H, at operation 4H-05, the UE NAS receives the MOI from the network through OAM or RRC signaling. The MOI indicates an element, such as "application" corresponding to each operator-specific access category.

At operation 4h-10, the UE NAS detects the access attempt.

At operation 4h-15, the UE NAS maps the access attempt to at least one access identity and access category. There may not be any corresponding access identities.

At operation 4h-20, the UE NAS sends a service request including the mapped access identities and access category information to the UE AS.

Fig. 4I is a flowchart illustrating operation of a UE AS according to an embodiment of the present disclosure.

Referring to fig. 4I, at operation 4I-05, the UE AS receives barring configuration information from the network via system information. The barring configuration information is provided per access identity and access category.

At operation 4i-10, the UE AS receives a service request including an access identity and access category information from the UE NAS.

At operation 4i-15, the UE AS determines whether to first allow access based on barring configuration information corresponding to the access identity. Two cases are considered. In one of the two cases, separate barring configuration information corresponding to the access identity is provided and the configuration information comprises the bitmap information proposed in the first or third embodiment. The UE AS determines whether at least one of the bits corresponding to the access category provided by the UE NAS is set to "0" in a bitmap of barring configuration information corresponding to the identity of the one or more mappings provided by the UE NAS, and if so, assumes that access is always allowed. For the barring configuration information of the first or second access identity, even the bitmap information proposed in the third embodiment is considered. The UE NAS simultaneously determines whether the bit corresponding to the access category is set to "0" and whether the UE belongs to the UE type indicated by the bitmap proposed in the third embodiment of the present disclosure. When the UE belongs to the UE type indicated by the bitmap and when the bit corresponding to the access category is set to "0", the access of the UE is allowed.

If access is not allowed using the separate barring configuration information corresponding to the access identity, the UE AS performs a barring check using the configuration information corresponding to the access category to determine whether access is eventually allowed.

In another case, the barring configuration information corresponding to the access category includes the bitmap information proposed in the second or third embodiment. Before performing a barring check using barring configuration information (i.e., ac-barring factors and ac-barring imes) of an access category provided by the UE NAS, the UE AS determines whether at least one bit corresponding to at least one access identity provided by the UE NAS in bitmap information proposed in the second embodiment is set to "0". If at least one bit is set to "0", access is allowed, omitting the barring check. For the case of the first or second identity, the UE type proposed in the third embodiment is further considered.

At operation 4i-20, the UE AS performs RRC connection establishment with the network and enters connected mode.

Fig. 4J is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure.

Referring to FIG. 4J, the UE includes Radio Frequency (RF) processors 4j-10, baseband processors 4j-20, memory units 4j-30, and controllers 4j-40.

The RF processors 4j-10 have functions of transmitting/receiving signals through radio channels, such as band conversion and amplification of the signals. For example, the RF processor 4j-10 up-converts a baseband signal from the baseband processor 4j-20 into an RF band signal, and transmits the RF signal via an antenna, and down-converts an RF signal received via the antenna into a baseband signal. For example, the RF processors 4j-10 may include transmit filters, receive filters, amplifiers, mixers, oscillators, DACs, and ADCs. Although one antenna is depicted in the drawing, the UE may be equipped with multiple antennas. The RF processors 4j-10 may also include multiple RF chains. The RF processors 4j-10 may perform beamforming. For beamforming, the RF processors 4j-10 may adjust the phase and magnitude of signals to be transmitted/received in phase and magnitude through an antenna or antenna element. The RF processor 4 j-1-may be configured to support a MIMO scheme by which the UE can receive multiple layers simultaneously.

The baseband processors 4j-20 have a baseband signal-to-bit string conversion function according to the physical layer standard of the system. For example, in the data transmission mode, the baseband processors 4j-20 perform coding and modulation on the transmission bit string to generate complex symbols. In the data reception mode, the baseband processor 4j-20 performs demodulation and decoding on the baseband signal from the RF processor 4j-10 to recover the transmitted bit string. In the case of using the OFDM scheme for data transmission, the baseband processors 4j-20 perform coding and modulation on a transmission bit string to generate complex symbols, map the complex symbols to subcarriers, perform inverse IFFT on the symbols, and insert CPs into the symbols to generate OFDM symbols. In the data reception mode, the baseband processors 4j-20 divide the baseband signals from the RF processors 1i-10 into OFDM symbols, perform FFT on the OFDM symbols to recover the signals mapped to the subcarriers, and perform demodulation and decoding on the signals to recover the transmitted bit strings.

The baseband processor 4j-20 and the RF processor 4j-10 process the transmission and reception signals as described above. Thus, the baseband processor 4j-20 and the RF processor 4j-10 may be referred to as a transmitter, a receiver, a transceiver or a communication unit. At least one of the baseband processor 4j-20 and the RF processor 4j-10 may include a plurality of communication modules for supporting different radio access technologies. At least one of the baseband processors 4j-20 and the RF processors 4j-10 may further include a plurality of communication modules for processing signals in different frequency bands. For example, different radio access technologies may include Wireless Local Area Networks (WLANs) (e.g., institute of Electrical and Electronics Engineers (IEEE) 802.11) and cellular networks (e.g., LTE). The different frequency bands may include the ultra high frequency (SHF) band (e.g., 2.5GHz and 5GHz bands) and the mmWave band (e.g., 60 GHz).

The storage units 4j-30 store data such as basic programs for operating the UE, application programs, and setting information. The memory units 4j-30 may also store information about a second access node that is wirelessly communicating using a second radio access technology. The storage unit 4j-30 provides the stored information in response to a request from the controller 4j-40.

The controllers 4j-40 control the overall operation of the UE. For example, the controller 4j-40 controls the baseband processor 4j-20 and the RF processor 4j-10 to transmit and receive signals. The controller 4j-40 writes data to the memory cell 4j-30 and reads data from the memory cell 4 j-30. To this end, the controllers 4j-40 may include at least one processor. For example, the controllers 4j-40 may include a CP for controlling communications and an AP for controlling higher layer programs (such as applications). The controllers 4j-40 may include multiple connection processors 4j-42 for processing operations in multiple connection mode.

According to an embodiment of the present disclosure, the UE may include some components depicted in the drawings, and the components of the UE are controlled by the controllers 4j-40.

Fig. 4K is a block diagram illustrating a configuration of a gNB according to an embodiment of the present disclosure.

Referring to fig. 4k, the gnb includes RF processors 4k-10, baseband processors 4k-20, backhaul communication units 4k-30, memory units 4k-40, and controllers 4k-50.

The RF processor 4k-10 has a function of transmitting/receiving signals through a radio channel, such as band conversion and amplification of the signals. For example, the RF processor 4k-10 up-converts a baseband signal from the baseband processor 4k-20 into an RF band signal, and transmits the RF signal via an antenna, and down-converts the RF signal received via the antenna into a baseband signal. For example, the RF processors 4k-10 may include transmit filters, receive filters, amplifiers, mixers, oscillators, DACs, and ADCs. Although one antenna is depicted in the drawing, the gNB may be equipped with multiple antennas. The RF processors 4k-10 may also include a plurality of RF chains. The RF processors 4k-10 may perform beamforming. For beamforming, the RF processors 4k-10 may adjust the phase and magnitude of signals to be transmitted/received through the antennas or antenna elements. The RF processors 4k-10 may be configured to transmit one or more layers of downlink MIMO operation.

The baseband processor 4k-20 has a baseband signal-to-bit string conversion function according to the physical layer standard of the system. For example, in the data transmission mode, the baseband processor 4k-20 performs coding and modulation on the transmission bit string to generate complex symbols. In the data reception mode, the baseband processor 4k-20 performs demodulation and decoding on the baseband signal from the RF processor 4k-10 to recover the transmitted bit string. In the case of using the OFDM scheme for data transmission, the baseband processors 4k-20 perform coding and modulation on a transmission bit string to generate complex symbols, map the complex symbols to subcarriers, perform IFFT on the symbols, and insert CPs into the symbols to generate OFDM symbols. In the data reception mode, the baseband processor 4k-20 divides the baseband signal from the RF processor 4k-10 into OFDM symbols, performs FFT on the OFDM symbols to recover the signal mapped to the subcarriers, and performs demodulation and decoding on the signal to recover the transmitted bit string. The baseband processor 4k-20 and the RF processor 4k-10 process the transmission and reception signals as described above. The baseband processor 4k-20 and the RF processor 4k-10 may thus be referred to as a transmitter, a receiver, a transceiver or a communication unit.

The backhaul communication units 4k-30 provide an interface for communicating with other nodes in the network. For example, the backhaul communication units 4k-30 convert a bit string to be transmitted from the gNB to another node (e.g., another gNB and a core network) into a physical signal, and convert a physical signal received from another node into a bit string.

The storage units 4k-40 store data such as basic programs, application programs, and setting information for the operation of the gNB. The memory units 4k-40 may also store information about bearers established for the UE and measurement results reported by the connected UE. The memory units 4k-40 may also store information for use by the UE in determining whether to enable or disable multi-connectivity. The memory unit 4k-40 may provide the stored data with reference to a request from the controller 4k-50.

The controllers 4k-50 control the overall operation of the gNB. For example, the controller 4k-50 controls the baseband processor 4k-20, the RF processor 4k-10, and the backhaul communication unit 4k-30 for transmitting and receiving signals. The controller 4k-50 reads and writes data to the memory unit 4 k-40. To this end, the controllers 4k-50 may comprise at least one processor. The controller 4k-50 may also include a multi-connection processor 4k-52 for processing operations in a multi-connection mode.

According to an embodiment of the present disclosure, the gNB may also include some of the components depicted in the figures, and the components of the gNB are controlled by controllers 4k-50.

Fifth embodiment

Embodiments of the present disclosure are described with reference to the drawings. A detailed description of well-known functions and configurations incorporated herein may be omitted to avoid obscuring the subject matter of the present disclosure. Further, the following terms are defined based on functions in the present disclosure and may vary according to the intention, use, and the like of a user or operator. Therefore, the definitions should be made based on the overall contents of the present specification.

In the following description, for convenience of explanation, terms indicating an access node, a network entity, a message, an interface between network entities, and different identification information are provided. Therefore, terms used in the following description are not limited to specific meanings, but may be replaced by other terms equivalent in technical meaning.

Fig. 5A is a diagram illustrating an architecture of an LTE system according to an embodiment of the present disclosure.

Referring to fig. 5a, the radio access network of the lte system includes evolved Node bs (hereinafter, interchangeably referred to as enbs, node bs, and base stations) 5a-05, 5a-10, 5a-15, and 5a-20; a Mobility Management Entity (MME) 5a-25; and a Serving Gateway (S-GW) 5a-30. The user terminals (hereinafter, interchangeably referred to as User Equipment (UE) and terminal) 5a-35 are connected to an external network via enbs 5a-05, 5a-10, 5a-15 and 5a-20 and S-GW 5a-30.

The eNBs 5a-05, 5a-10, 5a-15 and 5a-20 correspond to a legacy Node B of a Universal Mobile communications System (UMTS). The UEs 5a-35 are connected to one of the enbs via a radio channel, and the eNB has more complex functionality than a conventional Node B. In an LTE system in which all user traffic including real-time services such as Voice over IP (VoIP) is served through a shared channel, an entity is required to collect UE-specific state information such as a buffer state, a power headroom state, and a channel state and schedule UEs based on the collected information, and an eNB is responsible for these functions. Typically, one eNB carries multiple cells. For example, the LTE system employs Orthogonal Frequency Division Multiplexing (OFDM) as a radio access technology to secure a data rate of up to 100Mbps within a bandwidth of 20 MHz. The LTE system also employs Adaptive Modulation and Coding (AMC) to determine a modulation scheme and a channel coding rate to adapt to the channel conditions of the UE. The S-GW 5a-30 handles the data bearer functions to set up and release data bearers under the control of the MMEs 5 a-25. The MME 5a-25 handles various control functions for the UE as well as mobility management functions and interfaces with the eNBs 5a-05, 5a-10, 5a-15 and 5 a-20.

Fig. 5B is a diagram illustrating a protocol stack of an interface between a UE and an eNB in an LTE system according to an embodiment of the present disclosure.

Referring to fig. 5B, in the LTE system, a protocol stack of an interface between a UE and an eNB includes a plurality of protocol layers stacked from bottom to top: a physical layer denoted by reference numerals 5b-20 and 5b-25, a Medium Access Control (MAC) layer denoted by reference numerals 5b-15 and 5b-30, a Radio Link Control (RLC) layer denoted by reference numerals 5b-10 and 5b-35, and a packet data convergence Control (PDCP) layer denoted by reference numerals 5b-05 and 5 b-40. The PDCP layer denoted by reference numerals 5b-05 and 5b-40 is responsible for compressing/decompressing IP headers. The major functions of the PDCP layer are summarized as follows:

header compression and decompression: ROHC only

-user data transfer

Sequential delivery of upper layer PDUs during PDCP re-establishment procedure of RLC AM

For split bearers in DC (RLC AM only supported): PDCP PDU routing for transmission and PDCP PDU reordering for reception

Duplicate detection of lower SDUs during PDCP re-establishment procedure of RLC AM

-retransmitting PDCP SDUs at handover and PDCP PDUs at PDCP data recovery procedure of RLC AM for separate bearers in DC

-encryption and decryption

Timer-based SDU discard in uplink

The RLC layer designated by reference numerals 5b-10 and 5b-35 is responsible for reformatting the PDCP PDUs so that they fit into the size of the ARQ operation. The main functions of the RLC protocol are summarized as follows:

-transmission of upper layer PDU

Error correction by ARQ (for AM data transfer only)

Concatenation, segmentation and reassembly of RLC SDUs (for UM and AM data transfer only)

Re-segmentation of RLC data PDUs (for AM data transfer only)

Reordering of RLC data PDUs (for UM and AM data transfer only)

Duplicate detection (for UM and AM data transfer only)

Protocol error detection (for AM data transfer only)

RLC SDU discard (for UM and AM data transfer only)

RLC re-establishment

The MAC layer, denoted by reference numerals 5b-15 and 5b-30, allows establishing a connection of a plurality of RLC entities for one UE and is responsible for multiplexing RLC PDUs from the RLC layer into MAC PDUs and demultiplexing the MAC PDUs into RLC PDUs. The main functions of the MAC protocol are summarized as follows:

mapping between logical channels and transport channels

-multiplexing/demultiplexing MAC SDUs belonging to one or different logical channels into/from Transport Blocks (TBs) delivered from the physical layer on Transport channels

-scheduling information reporting

HARQ function (error correction by HARQ)

-priority handling between logical channels of one UE

-prioritization among UEs by dynamic scheduling

-MBMS service identification

-transport format selection

-filling

The PHY layer, denoted by reference numerals 5b-20 and 5b-25, is responsible for channel coding and modulating the higher layer data to generate and transmit OFDM symbols on a radio channel, and demodulating and channel decoding OFDM symbols received on the radio channel to deliver the decoded data to the higher layer.

Fig. 5C is a diagram illustrating an architecture of a next generation mobile communication system according to an embodiment of the present disclosure.

Referring to fig. 5C, the radio access network 5C-20 of the next generation mobile communication system includes a new radio Node B (RN NB) 5C-10 and a new radio core network (NR CN) 5C-05. The new radio user equipment (hereinafter referred to as NR UE or simply UE) 5c-15 is connected to the external network via NR NB 5c-10 and NR CN 5c-05.

In fig. 5C, the NR NB 5C-10 corresponds to an evolved Node B (eNB) in the conventional LTE system. The NR UEs 5c-15 are connected to a NR NB which can provide services better than legacy enbs. In the next generation mobile communication system in which all user traffic is served through a shared channel, an entity is required to collect UE-specific state information (such as buffer status, power headroom status, and channel status) and schedule UEs based on the collected information, and the NR NB 5c-10 is responsible for these functions. Typically, one NR NB carries multiple cells. In order to satisfy the higher data rate requirement than the conventional LTE, it is necessary to secure the maximum bandwidth wider than ever by employing advanced techniques such as Orthogonal Frequency Division Multiplexing (OFDM) as a radio access scheme and beamforming. An Adaptive Modulation and Coding (AMC) technique may be employed to determine a modulation scheme and a channel coding rate to adapt to the channel condition of the UE. The NR CN5c-05 is responsible for mobility management, bearer establishment and QoS establishment. The NR CN5c-05 is responsible for other control functions as well as UE mobility management functions related to multiple NR NBs. The next generation mobile communication system can interoperate with a conventional LTE system in such a manner that the NR CN5c-05 is connected to a Mobility Management Entity (MME) 5c-25 through a network interface. The MME 5c-25 is connected to the eNB 5c-30 which is a legacy base station.

Fig. 5D is a diagram illustrating a protocol stack of an interface between NR UE and NR gbb in a next generation mobile communication system according to an embodiment of the present disclosure.

Referring to fig. 5D, in the next generation mobile communication system, a protocol stack of an interface between the NR UE and the NR gbb includes a plurality of protocol layers stacked from bottom to top: the NR PHY layers denoted by reference numerals 5d-20 and 5d-25, the NR MAC layers denoted by reference numerals 5d-15 and 5d-30, the NR RLC layers denoted by reference numerals 5d-10 and 5d-35, and the NR PDCP layers denoted by reference numerals 5d-05 and 5 d-40. The main functions of the NR PDCP layer, denoted by reference numerals 5d-05 and 5d-40, may include some of the following functions:

header compression and decompression: ROHC only

-user data transfer

-sequential delivery of upper layer PDUs

Out-of-order delivery of upper layer PDUs

-PDCP PDU reordering for reception

Duplicate detection of lower layer SDUs

-retransmission of PDCP SDU

-encryption and decryption

Timer-based SDU discard in uplink

The PDCP PDU reordering function of the NR PDCP entity is to reorder PDCP PDUs delivered from a lower layer based on PDCP sequence number (PDCP SN), and may include delivering reordered data to an upper layer, recording a missing PDCP PDU among the reordered PDCP PDUs, transmitting a status report indicating the missing PDCP PDU to a transmitting side, and requesting retransmission of the missing PDCP PDU.

The main functions of the NR RLC layer, denoted by reference numerals 5d-10 and 5d-35, may include some of the following functions.

-transmission of upper layer PDU

-sequential delivery of upper layer PDUs

Out-of-order delivery of upper layer PDUs

Error correction by ARQ

Concatenation, segmentation and reassembly of RLC SDUs

-re-segmentation of RLC data PDUs

Reordering of RLC data PDUs

-duplicate detection

-protocol error detection

RLC SDU discard

RLC re-establishment

The sequential delivery function of the NR RLC entity is to deliver RLC SDUs received from a lower layer to an upper layer, and may include: when a plurality of segmented RLC SDUs constituting an original RLC SDU are received, recombining the RLC SDUs and transferring the recombined RLC SDUs to an upper layer; reordering the received RLC PDUs based on an RLC Sequence Number (SN) or a PDCP SN; recording the RLC PDU lost in the reordered RLC PDUs; sending a status report indicating the missing RLC PDUs to the sender; requesting retransmission of the missing RLC PDU; and sequentially delivering RLC PDUs prior to the missing RLC PDU to an upper layer when there is the missing RLC PDU, sequentially delivering all RLC PDUs received before the timer is started to the upper layer if the predetermined timer expires even though there is any missing RLC SDU, or sequentially delivering all RLC PDUs received until then to the upper layer if the predetermined timer expires even though there is any missing RLC SDU. It is also possible to process RLC PDUs in the order of reception (in order of arrival without considering sequence numbers) and deliver the RLC PDUs out of order to the PDCP entity (out of order delivery) and, if the RLC PDUs are sent in segments (segment), store the received segments or wait until all the segments constituting the RLC PDUs are received and reassemble the segments into the original RLC PDU delivered to the PDCP entity. The NR RLC layer may have no concatenation function, and in this case, the concatenation function may be performed in the NR MAC layer or replaced by a multiplexing function of the NR MAC layer.

The out-of-order delivery function of the NR RLC entity is to deliver RLC SDUs received from a lower layer to an upper layer out of order, and may include: when a plurality of segmented RLC SDUs constituting an original RLC SDU are received, the segmented RLC SDUs are reassembled, the reassembled RLC SDUs are delivered to an upper layer, the received RLC PDUs are aligned based on RLC SNs or PDCP SNs, and SNs of the missing RLC PDUs are recorded.

In the NR MAC layer denoted by reference numerals 5d-15 and 5d-30, a NR MAC entity may be connected to a plurality of NR RLC entities, and the main functions of the NR MAC entity may include some of the following functions:

mapping between logical channels and transport channels

-multiplexing/demultiplexing MAC SDU

-scheduling information reporting

Error correction by HARQ

-priority handling between logical channels of one UE

-prioritization among UEs by dynamic scheduling

-MBMS service identification

-transport format selection

-filling

The NR PHY layer, denoted by reference numerals 5d-20 and 5d-25, is responsible for channel coding and modulation of upper layer data to generate and transmit OFDM symbols on a radio channel, and demodulates and channel decodes OFDM symbols received on the radio channel to deliver the decoded data to the upper layer.

In the next generation mobile communication system supporting a high data rate, if PDCP PDUs are lost or arrive with a delay in a single connection environment, if the PDCP PDUs are discarded at a transmitter due to the expiration of a PDCP expiration timer, or if one of two PDCP entities delays receiving the PDCP PDUs in a dual connection environment, all received data should be stored in a buffer until a reordering timer triggered at a receiving PDCP layer expires, thereby causing a transmission delay. Therefore, the terminal must have a mass memory or buffer to store all data received while the reordering timer is running. If the memory or buffer capacity is insufficient, data loss may occur. If data that has triggered the PDCP reordering timer arrives before the timer expires or if the PDCP reordering timer expires, a large amount of data received while the timer is running may be delivered to an upper layer at once, and thus the upper layer may not be able to process all data, resulting in data loss.

The present disclosure proposes a novel PDCP status reporting method characterized in that, when a predetermined timer operating at a receiving PDCP layer expires, when the amount of data stored in a reception buffer becomes equal to or greater than a threshold value, or when a reordering timer value reaches a predetermined time, a receiver triggers a PDCP status report and transmits the PDCP status report to a transmitter, and the transmitter receives and checks the PDCP status report to discard data (PDCP PDUs or PDCP SDUs) successfully received by the receiver and rapidly retransmit the missing data, thereby solving the transmission delay and data loss problems caused by the reordering timer operating at the receiver.

The novel PDCP status reporting method can enable a transmitter to discard data successfully received by a receiver when receiving a PDCP status report from the receiver, and immediately retransmit the lost data based on the PDCP status report.

Fig. 5E is a signal flow diagram illustrating a procedure for the gNB to configure a Packet Data Convergence Protocol (PDCP) status report request function via an RRC message when the UE establishes a connection with the network, according to an embodiment of the present disclosure.

Fig. 5E depicts a process in which the UE transitions from an RRC idle mode or an RRC inactive mode (or light-connected mode) to an RRC connected mode to establish a connection with the network and configure whether to enable the PDCP status report request function.

Referring to fig. 5E, if data is not transmitted to or received from the UE in the RRC connected mode in a predetermined procedure or within a predetermined period of time, the gNB may transmit an RRCConnectionRelease message to the UE at operation 5E-01, so that the UE enters an idle mode. Thereafter, any data to be transmitted occurs, and the UE in idle mode (hereinafter, interchangeably referred to as idle mode UE) performs an RRC connection establishment procedure with the gNB. If the UE is in RRC inactive mode, it may send an rrcconnectionresumerrequest message to perform an RRC connection recovery procedure. At operation 5e-05, the UE achieves uplink synchronization with the gNB through a random access procedure and sends an RRCConnectionRequest message to the gNB. The RRCConnectionRequest message includes a UE identifier and an establishment cause (estabilishmenticause). At operation 5e-10, the gNB sends an RRCConnectionSetup message to the UE for establishing a connection with the UE. The message may include information indicating whether the new PDCP status report is enabled per logical channel (logical channel), per bearer, or per PDCP entity (PDCP-config). In more detail, an IP flow or QoS flow for which new PDCP status report is enabled may be indicated on each logical channel, each bearer, or each PDCP (or SDAP) entity. The new PDCP status report may be enabled by configuring a buffer threshold or a newly introduced timer or a threshold of a reordering timer as a condition for triggering the new PDCP status report. This may trigger a new PDCP status report if the amount of data in the buffer of the PDCP or RLC entity reaches a threshold, or if a newly introduced timer or reordering timer reaches a threshold. The RRCConnectionSetup message also includes RRC connection configuration information. The RRC connection is called a Signaling Radio Bearer (SRB) and is established for exchanging RRC messages as control messages between the UE and the gNB. After establishing the RRC connection, the UE sends an RRCConnectionSetupComplete message to the gNB at operation 5 e-15. If the gNB does not know and wants to know the capabilities of the UE connected to it, it may send a message asking for the capabilities of the UE. The message may include an indicator indicating whether the UE has new PDCP status reporting capability or supports new PDCP status reporting. The RRCConnectionSetupComplete message includes a control message called SERVICE REQUEST for the UE to use when requesting access to the MME and a Mobility Management Function (AMF), a User Plane Function (UPF), or a Session Management Function (SMF) for bearer establishment for a specific SERVICE. At operation 5E-20, the gNB sends a SERVICE REQUEST message to the MME/AMF/UPF/SMF, and the MME/AMF/UPF/SMF determines whether to provide the UE's SERVICE REQUEST. If it is determined to provide the service requested by the UE, the MME/AMF/UPF/SMF sends an INITIAL CONTEXT SETUP REQUEST message to the gNB at operation 5 e-25. The message includes Quality of Service (QoS) information for configuring a Data Radio Bearer (DRB) and security information (e.g., a security key and a security algorithm) to be applied to the DRB. The gNB sends a SecurityModeCommand message to the UE at operation 5e-30 and receives a SecurityModecomplete message from the UE for security configuration at operation 5 e-35. After the security configuration is completed, the gNB sends an RRCConnectionReconfiguration message to the UE at operation 5 e-40. The message includes information indicating whether a new PDCP status report is enabled per logical channel (logical channel), per bearer, or per PDCP entity (PDCP-config). In more detail, an IP flow or QoS flow for which new PDCP status report is enabled may be indicated on each logical channel, each bearer, or each PDCP (or SDAP) entity. The new PDCP status report may be enabled by configuring a buffer threshold or a newly introduced timer or a threshold of a reordering timer as a condition for triggering the new PDCP status report. In this case, if the amount of data in the buffer of the PDCP or RLC entity reaches a threshold, or if a newly introduced timer or a reordering timer reaches a threshold, this may trigger a new PDCP status report. The RRCConnectionReconfiguration message further includes information for configuring a DRB for user data transmission, and the UE configures the DRB based on the DRB configuration information and transmits the RRCConnectionReconfiguration complete message to the gNB at operation 5 e-45. After establishing the DRB with the UE, the gNB transmits an INI CONTEXT RESPONSE message to the MME at operation 5e-50, the MME transmits an S1 BEARER SETUP message to the S-GW upon receiving the INI CONTEXT RESPONSE message for establishing the S1 BEARER with the S-GW at operation 5e-55, and receives the S1 BEARER SETUP RESPONSE message from the S-GW at operation 5 e-60. The S1 bearer is a connection for data transfer established between the S-GW and the gNB, and corresponds one-to-one to the DRB. Once the above procedure is successfully completed, the UE transmits and receives data via the gNB and S-GW at operations 5e-65 and 5 e-70. The data transmission process can be divided into three stages: RRC connection configuration, security configuration, and DRB configuration. At operations 5e-75, the gNB may also send an RRCConnectionReconfiguration message to the UE to update, supplement, or modify the configuration to the UE. The message includes information indicating whether a new PDCP status report is enabled per logical channel (logical channel), per bearer, or per PDCP entity (PDCP-config). In more detail, an IP flow or QoS flow for which new PDCP status report is enabled may be indicated on each logical channel, each bearer, or each PDCP (or SDAP) entity. The new PDCP status report may be enabled by configuring a buffer threshold or a newly introduced timer or a threshold of a reordering timer as a condition for triggering the new PDCP status report. In this case, if the amount of data in a buffer for the PDCP or RLC entity reaches a threshold, or if a newly introduced timer or a reordering timer reaches a threshold, this may trigger a new PDCP status report.

Fig. 5F is a diagram illustrating a transmission delay and data loss problem caused by a PDCP reordering timer of a PDCP entity according to an embodiment of the present disclosure.

Referring to fig. 5F, the transmitting PDCP entity may transmit data (PDCP PDU or PDCP SDU) having 12 PDCP sequence numbers (0,1,2,3.., 2^ (12-1)), and the receiving PDCP entity may receive the data out of order rather than in ascending order of the PDCP sequence numbers due to HARQ retransmission of the MAC entity or ARQ retransmission of the RLC entity according to the condition of the radio link. In case that a PDCP discard timer of a transmitting PDCP entity expires or data loss occurs on a radio link, the PDCP entity may fail to receive data (PDCP PDU or PDCP SDU) having a specific PDCP sequence number or receive the data too late.

In fig. 5F, in case that data (PDCP PDU or PDCP SDU) having a PDCP sequence number 2 does not arrive, the data (PDCP PDU or PDCP SDU) having a PDCP sequence number 3 may arrive at the receiving PDCP entity denoted by reference numeral 5F-05. In this case, the receiving PDCP entity triggers a PDCP reordering timer to receive data (PDCP PDUs or PDCP SDUs) having a PDCP sequence number for sequentially delivering the data to an upper layer, as shown by reference numerals 5 f-10. The PDCP reordering timer indicates a time when the PDCP entity waits for the arrival of the lost data, and if the PDCP reordering timer expires, the receiving PDCP entity determines that data not yet arrived among data having a PDCP sequence number smaller than the PDCP sequence number whose PDCP reordering timer has been triggered is lost, and delivers the data having the PDCP sequence number smaller than the PDCP sequence number whose PDCP reordering timer has been triggered to an upper layer in an ascending order of the PDCP sequence number.

However, for a service requiring a high data rate, if the PDCP reordering timer is set to a long period as before, it is necessary to buffer a large amount of received data because data cannot be delivered to an upper layer until the PDCP reordering timer expires or lost data arrives, as shown by reference numerals 5 f-15; increasing the size of the buffer or memory is expensive and therefore increases the overall manufacturing cost of the UE. In a state where a large amount of data is stored in the buffer due to an arrival delay of some data, if a reordering timer expires or missing data arrives, all data stored in the buffer is delivered to an upper layer at once. In this case, the upper layer may not be able to correctly process a large amount of data, and thus discard the data at a predetermined level or a predetermined rate, resulting in data loss.

To solve the problem described with reference to fig. 5F, the present disclosure proposes a new PDCP status report, a method for triggering the new PDCP status report, and operations of a transmitting PDCP entity and a receiving PDCP entity.

Fig. 5G is a diagram illustrating a format of a first type PDCP status report according to an embodiment of the present disclosure.

Referring to fig. 5G, according to an embodiment of the present disclosure, the first type PDCP status report may be configured in formats 2G-05 for the case of using 12-bit PDCP sequence numbers, 2G-10 for the case of using 18-bit PDCP sequence numbers, and 2G-15 for the case of using 32-bit PDCP count values. In formats 5g-05, 5g-10 and 5g-15, the D/C field indicates whether buffered data is PDCP user data (PDCP data PDU) or PDCP control data (PDCP control PDU), and the PDU type field indicates the type of PDCP control PDU. A First Missing Sequence number (FMS) field indicates a Sequence number of a First Missing PDU, and a First Missing Count value (FMC) field indicates a PDCP Count value of the First Missing PDU within a received reordering window. The bitmap field following the FMC or FMS field is composed of a plurality of bits mapped to PDCP PDUs having consecutive PDCP sequence numbers or PDCP count values in an ascending order, each bit being set to 0 or 1 to indicate whether corresponding PDCP data is successfully received.

To indicate the use of the first type PDCP status report proposed in this disclosure, the PDU type field is set to 011 as shown in table 4. One of the other reserved values (e.g., 100 to 111) may also be used.

[ Table 4]

To solve the problem caused by the transmission delay of the PDCP reordering timer described with reference to fig. 5F, the receiver may trigger the first type PDCP status report proposed in the present disclosure in the following case. For example, if the UE predicts the occurrence of the above problem, it triggers a first type PDCP status report by transmitting the first type PDCP status report to the transmitter to request rapid retransmission of lost data (PDCP PDU or PDCP SDU).

The receiver may trigger the first type PDCP status report when at least one of the following conditions is satisfied.

1. The amount of data stored in the receive buffer or memory is equal to or greater than a predetermined amount,

2. the amount of data stored in the receive buffer or memory is equal to or greater than a threshold configured via RRC messages,

3. a new timer configured via an RRC message expires,

pdcp reordering timer reaches a value configured via RRC message,

5. according to an embodiment, a first type PDCP status report request is required,

6. receiving an RRC message indicating a request for a first type PDCP status report,

7. data having a PDCP header including a 1-bit polling indicator is received,

8. a PDCP control PDU indicating a request for a first type PDCP status report request, and

the MAC entity receives a MAC CE indicating a request for a first status report.

The RRC message may be one of the RRC messages sent in operations 5E-10, 5E-40, 5E-75 in fig. 5E.

In an embodiment of the present disclosure, the transmitter may transmit an RRC message or request for a first type PDCP status report to the receiver via the MAC CE, the PDCP header, or the PDCP control PDU when one of the following conditions is satisfied.

1. The transmitter may periodically request the first type PDCP status report from the receiver via an indicator included in an RRC message, a MAC CE, or a PDCP control PDU whenever the newly defined timer expires.

2. The transmitter may periodically request a first type PDCP status report from the receiver via a 1-bit indicator (e.g., PDCP poll bit) defined in the PDCP header whenever the newly defined timer expires.

3. According to an embodiment of the transmitter, the transmitter may request the first type PDCP status report to the receiver via an indication in an RRC message, MAC CE or PDCP control PDU.

4. The transmitter may request the first type PDCP status report from the receiver by configuring a 1-bit indicator (e.g., PDCP poll bit) defined in the PDCP header, according to an implementation or determination of the transmitter.

The newly defined timer may be a timer for a first type PDCP status report, e.g., t-StatusReportType3.

In the present disclosure, when the first type PDCP status report is triggered, the receiver or the receiving PDCP entity operates as follows.

If the first type PDCP status report is triggered at the receiver according to the above first type PDCP status report triggering condition, the receiver can distinguish between successfully received data and lost data associated with a PDCP sequence number or a PDCP COUNT value (a PDCP sequence number or a PDCP COUNT value belonging to a PDCP reception window) which is less than an RX-REORD variable indicating a PDCP sequence number or a PDCP COUNT value at which the PDCP reordering status report is triggered among PDCP reception window variables; configuring a D/C field, a PDU type field, an FMC or FMS field, and a bitmap field of the data format depicted in fig. 5G to generate a first type PDCP status report; and transmits the first type PDCP status report to the receiver.

Alternatively, if the first type PDCP status report is triggered at the receiver according to the above first type PDCP status report triggering condition, the receiver may distinguish between successfully received data and lost data associated with a PDCP sequence number or a PDCP COUNT value (a PDCP sequence number or a PDCP COUNT value belonging to a PDCP reception window) which is less than an RX-REORD variable indicating a PDCP sequence number or a PDCP COUNT value predicted to be received next among PDCP reception window variables; configuring the D/C field, the PDU type field, the FMC or FMS field, and the bitmap field of the data format depicted in fig. 5G to generate a first type PDCP status report; and transmits the first type PDCP status report to the receiver.

Alternatively, if the first type PDCP status report is triggered at the receiver according to the above first type PDCP status report triggering condition, the receiver may distinguish between successfully received data and lost data associated with a PDCP sequence number or a PDCP COUNT value (a PDCP sequence number or a PDCP COUNT value belonging to a PDCP reception window) which is less than an RX-REORD variable indicating a first PDCP sequence number or a PDCP COUNT value of which data of an upper layer has not been transferred among PDCP reception window variables; configuring the D/C field, the PDU type field, the FMC or FMS field, and the bitmap field of the data format depicted in fig. 5G to generate a first type PDCP status report; and transmits the first type PDCP status report to the receiver.

In the present disclosure, when receiving the first type PDCP status report, the transmitter or the transmitting PDCP entity operates as follows.

If the first type PDCP status report is received, the transmitting PDCP entity can check successfully transmitted data (PDCP PDU or PDCP SDU) and missing data, discard the successfully transmitted data from the transmission buffer, and retransmit the missing data stored in the buffer. For example, the transmitting PDCP entity may retrieve the lost data from the transmit buffer and transmit the retrieved data to a lower layer for retransmission. In order to enable the lower layer to preferentially transmit retransmission target data of the PDCP entity, the PDCP entity may transmit a fast delivery or accelerated delivery indicator to the lower layer. If the indicator is received, the lower layer (RLC entity) assumes data from the upper layer as retransmission target data (PDCP PDU) and preferentially transmits the corresponding data.

Alternatively, if the first type PDCP status report is received, the transmitting PDCP entity may check successfully transmitted data (PDCP PDUs or PDCP SDUs) and missing data, discard the successfully transmitted data from the transmission buffer, and retrieve the missing data that has been transmitted to a lower layer for retransmission. For example, the transmitting PDCP entity may retrieve the lost data from the transmit buffer and transmit the retrieved data to a lower layer for retransmission. In order to enable the lower layer to preferentially transmit retransmission target data of the PDCP entity, the PDCP entity may transmit a fast delivery or accelerated delivery indicator to the lower layer. If the indicator is received, the lower layer (RLC entity) assumes data from the upper layer as retransmission target data (PDCP PDU) and preferentially transmits the corresponding data.

According to an embodiment of the present disclosure, a second type PDCP status report may be defined and used in addition to the first type PDCP status report. As described above, the first type PDCP status report is characterized in that if the transmitter receives the first type PDCP status report, it discards successfully transmitted data and rapidly retransmits the lost data. However, in case of the second type PDCP status report, although the transmitter immediately discards successfully transmitted data after receiving the second type PDCP status report, it retransmits the lost data only when performing a PDCP re-establishment procedure or a PDCP data recovery procedure, instead of immediately after receiving the second type PDCP status report.

Both the first and second type PDCP status reports may use the format depicted in fig. 5G except for the difference in PDU type field values. The above-described first type PDCP status report triggering condition may be applied to the second type PDCP status report in the same manner. The first and second type PDCP status reports may be configured in the same manner. Therefore, it is apparent that the second type PDCP status report can be used on behalf of the first type PDCP status report in the present disclosure.

Figure 5H depicts a flowchart illustrating the operation of the sending PDCP entity and the receiving PDCP entity for handling the proposed PDCP status report according to an embodiment of the present disclosure.

Referring to fig. 5H, if one of the above-described trigger conditions is satisfied to trigger the PDCP status report at operation 5H-05, the receiving PDCP entity configures the PDCP status report at operation 5H-10 and transmits the PDCP status report in the format described with reference to fig. 5G at operation 5H-15. If the transmitting PDCP entity receives the PDCP status report at operation 5h-20, it may discard the successfully transmitted data and perform retransmission of the lost data at operation 5 h-25. The transmitting PDCP entity may also transmit an indicator indicating a priority of transmission of retransmission target data to a lower layer.

According to another embodiment of the present disclosure, for the case where a new PDCP status report request function is configured for a PDCP entity or bearer using one of the RRC messages transmitted at operations 5E-10, 5E-40, 5E-75 in fig. 5E, if the transmitter requests a new PDCP status report to the receiver via a 1-bit polling indicator of a PDCP header, a PDCP control PDU, a MAC CE, or an RRC message, or if the above-described PDCP status report triggering condition of the receiver is satisfied, the receiver triggers a first type PDCP status report proposed in the present disclosure, and the transmitter checks the first type PDCP status report to discard successfully transmitted data and immediately perform retransmission of lost data. However, for the case where the PDCP entity or bearer does not configure the new PDCP status report request function using one of the RRC messages transmitted at operations 5E-10, 5E-40, 5E-75 in fig. 5E, if the transmitter requests the new PDCP status report to the receiver via a 1 bit polling indicator of the PDCP header, a PDCP control PDU, a MAC CE, or an RRC message, or if the above-described PDCP status report triggering condition of the receiver is satisfied, the receiver triggers a second type PDCP status report proposed in the present disclosure, and the transmitter checks the second type PDCP status report to discard successfully transmitted data, and performs retransmission of lost data only when performing a PDCP re-establishment procedure or a PDCP data recovery procedure, rather than immediately when receiving the second type PDCP status report.

Fig. 5I is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure.

Referring to FIG. 5I, the UE includes a Radio Frequency (RF) processor 5i-10, a baseband processor 5i-20, a storage unit 5i-30, and a controller 5i-40.

The RF processors 5i-10 have functions of transmitting/receiving signals through radio channels, such as band conversion and amplification of the signals. For example, the RF processors 5i-10 up-convert baseband signals from the baseband processors 5i-20 into RF band signals, and transmit the RF signals via an antenna, and down-convert RF signals received via the antenna into baseband signals. For example, the RF processors 5i-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC. Although one antenna is depicted in the drawing, the UE may be equipped with multiple antennas. The RF processors 5i-10 may also comprise a plurality of RF chains. The RF processors 5i-10 may perform beamforming. For beamforming, the RF processors 5i-10 may adjust the phase and magnitude of signals to be transmitted/received in phase and magnitude through an antenna or antenna element. The RF processor 5 i-1-may be configured to support a MIMO scheme by which the UE can simultaneously receive a plurality of layers. The RF processors 5I-10 may suitably configure a plurality of antennas or antenna elements under the control of the controllers 5I-40 to perform beam scanning and adjust beam direction and beam width to achieve alignment of the receive and transmit beams.

The baseband processor 5i-20 has a baseband signal-to-bit string conversion function according to the system physical layer standard. For example, in the data transmission mode, the baseband processors 5i-20 perform coding and modulation on the transmission bit string to generate complex symbols. In the data reception mode, the baseband processor 5i-20 performs demodulation and decoding on the baseband signal from the RF processor 5i-10 to recover the transmitted bit string. In the case of using the OFDM scheme for data transmission, the baseband processors 5i-20 perform coding and modulation on a transmission bit string to generate complex symbols, map the complex symbols to subcarriers, perform IFFT on the symbols, and insert a Cyclic Prefix (CP) into the symbols to generate OFDM symbols. In the data reception mode, the baseband processor 5i-20 divides the baseband signal from the RF processor 5i-10 into OFDM symbols, performs FFT on the OFDM symbols to recover the signal mapped to the subcarriers, and performs demodulation and decoding on the signal to recover the transmitted bit string.

The baseband processor 5i-20 and the RF processor 5i-10 process the transmission and reception signals as described above. Thus, the baseband processor 5i-20 and the RF processor 5i-10 may be referred to as a transmitter, a receiver, a transceiver or a communication unit. At least one of the baseband processor 5i-20 and the RF processor 5i-10 may comprise a plurality of communication modules for supporting different radio access technologies. At least one of the baseband processors 5i-20 and the RF processors 5i-10 may further include a plurality of communication modules for processing signals in different frequency bands. For example, different radio access technologies may include Wireless Local Area Networks (WLANs) (e.g., institute of Electrical and Electronics Engineers (IEEE) 802.11) and cellular networks (e.g., LTE). The different frequency bands may include the ultra high frequency (SHF) band (e.g., 2.5GHz and 5GHz bands) and the mmWave band (e.g., 60 GHz).

The storage units 5i-30 store data such as basic programs, application programs, and setting information for the operation of the UE. The storage unit 5i-30 provides the stored information in response to a request from the controller 5i-40.

The controllers 5i-40 control the overall operation of the UE. For example, the controller 5i-40 controls the baseband processor 5i-20 and the RF processor 5i-10 to transmit and receive signals. The controllers 5i-40 write data to the memory cells 5i-30 and read data from the memory cells 5 i-30. To this end, the controllers 5i-40 may comprise at least one processor. For example, the controllers 5i-40 may include a CP for controlling communication and an AP for controlling higher layer programs (such as applications). The controllers 5i-40 may include multiple connection processors 5i-42 for processing operations in multiple connection mode.

According to an embodiment of the present disclosure, the UE may include some components depicted in the drawings, and the components of the UE are controlled by the controllers 5i-40.

Fig. 5J is a block diagram illustrating a configuration of a gNB according to an embodiment of the present disclosure.

Referring to fig. 5j, the gnb includes RF processors 5j-10, baseband processors 5j-20, backhaul communication units 5j-30, storage units 5j-40, and controllers 5j-50.

The RF processors 5j-10 have functions of transmitting/receiving signals through radio channels, such as band conversion and amplification of the signals. For example, the RF processor 5j-10 up-converts a baseband signal from the baseband processor 5j-20 into an RF band signal, and transmits the RF signal via an antenna, and down-converts the RF signal received via the antenna into a baseband signal. For example, the RF processors 5j-10 may include transmit filters, receive filters, amplifiers, mixers, oscillators, DACs, and ADCs. Although one antenna is depicted in the drawing, the gbb may be equipped with multiple antennas. The RF processors 5j-10 may also include a plurality of RF chains. The RF processors 5j-10 may perform beamforming. For beamforming, the RF processors 5j-10 may adjust the phase and magnitude of signals to be transmitted/received through the antennas or antenna elements. The RF processors 5j-10 may be configured to transmit one or more layers of downlink MIMO operation.

The baseband processor 5j-20 has a baseband signal-to-bit string conversion function according to the physical layer standard of the system. For example, in the data transmission mode, the baseband processors 5j-20 perform coding and modulation on the transmission bit string to generate complex symbols. In the data reception mode, the baseband processor 5j-20 performs demodulation and decoding on the baseband signal from the RF processor 5j-10 to recover the transmitted bit string. In the case of using the OFDM scheme for data transmission, the baseband processors 5j-20 perform coding and modulation on a transmission bit string to generate complex symbols, map the complex symbols to subcarriers, perform IFFT on the symbols, and insert CPs into the symbols to generate OFDM symbols. In the data reception mode, the baseband processor 5j-20 divides the baseband signal from the RF processor 5j-10 into OFDM symbols, performs Fast Fourier Transform (FFT) on the OFDM symbols to recover the signals mapped to the subcarriers, and performs demodulation and decoding on the signals to recover the transmitted bit string. The baseband processor 5j-20 and the RF processor 5j-10 process the transmission and reception signals as described above. Thus, the baseband processor 5j-20 and the RF processor 5j-10 may be referred to as a transmitter, a receiver, a transceiver or a communication unit.

The backhaul communication units 5j-30 provide interfaces for communicating with other nodes in the network.

The storage units 5j-40 store data such as basic programs, application programs, and setting information for the operation of the gNB. The memory units 5j-40 may also store information about bearers established for the UE and measurement results reported by the connected UE. The memory units 5j-40 may also store information for the UE to use in determining whether to enable or disable the multi-connection. The memory units 5j-40 may provide stored data with reference to a request from the controller 5j-50.

Controllers 5j-50 control the overall operation of the gNB. For example, the controller 5j-50 controls the baseband processor 5j-20, the RF processor 5j-10, and the backhaul communication unit 5j-30 for transmitting and receiving signals. The controllers 5j-50 write data to the memory cells 5j-40 and read data from the memory cells 5 j-40. To this end, the controllers 5j-50 may comprise at least one processor. The controllers 5j-50 may also include multiple connection processors 5j-52 for processing operations in multiple connection mode.

According to an embodiment of the present disclosure, the gNB may also include some of the components depicted in the figures, and the components of the gNB are controlled by controllers 5j-50.

Sixth embodiment

Embodiments of the present disclosure are described with reference to the drawings. A detailed description of known functions and configurations incorporated herein may be omitted to avoid obscuring the subject matter of the present disclosure. Further, the following terms are defined based on functions in the present disclosure and may vary according to the intention, use, and the like of a user or operator. Therefore, the definitions should be made based on the overall contents of the present specification. In the following description, for convenience of explanation, terms indicating an access node, a network entity, a message, an interface between network entities, and different identification information are provided. Therefore, terms used in the following description are not limited to specific meanings, but may be replaced by other terms equivalent in technical meaning.

Fig. 6A is a diagram illustrating an architecture of an LTE system according to an embodiment of the present disclosure.

Referring to fig. 6a, the radio access network of the lte system includes evolved Node bs (hereinafter, interchangeably referred to as enbs, node bs, and base stations) 6a-05, 6a-10, 6a-15, and 6a-20; a Mobility Management Entity (MME) 6a-25; and a serving gateway (S-GW) 6a-30. The user terminals (hereinafter, interchangeably referred to as User Equipment (UE) and terminal) 6a-35 are connected to the external network via the enbs 6a-05, 6a-10, 6a-15 and 6a-20 and the S-GW 6a-30.

The eNBs 6a-05, 6a-10, 6a-15 and 6a-20 correspond to legacy Node Bs of the Universal Mobile Telecommunications System (UMTS). The UEs 6a-35 are connected to one of the enbs via a radio channel, and the eNB has more complex functionality than a conventional Node B. In an LTE system in which all user traffic including real-time services such as voice over IP (VoIP) is served through a shared channel, an entity is required to collect UE-specific status information such as buffer status, power headroom status, and channel status and schedule UEs based on the collected information, and an eNB is responsible for these functions. Typically, one eNB carries multiple cells. For example, the LTE system employs Orthogonal Frequency Division Multiplexing (OFDM) as a radio access technology to secure a data rate of up to 100Mbps within a bandwidth of 20 MHz. The LTE system also employs Adaptive Modulation and Coding (AMC) to determine a modulation scheme and a channel coding rate to adapt to the channel conditions of the UE. The S-GW 6a-30 handles the data bearer functions to set up and release data bearers under control of the MME 6 a-25. The MME 6a-25 handles various control functions for the UE as well as mobility management functions and interfaces with the eNBs 6a-05, 6a-10, 6a-15 and 6 a-20.

Fig. 6B is a diagram illustrating a protocol stack of an interface between a UE and an eNB in an LTE system according to an embodiment of the present disclosure.

Referring to fig. 6B, in the LTE system, a protocol stack of an interface between a UE and an eNB includes a plurality of protocol layers stacked from bottom to top: a physical layer denoted by reference numerals 6b-20 and 6b-25, a Medium Access Control (MAC) layer denoted by reference numerals 6b-15 and 6b-30, a Radio Link Control (RLC) layer denoted by reference numerals 6b-10 and 6b-35, and a packet data convergence control (PDCP) layer denoted by reference numerals 6b-05 and 6 b-40. The PDCP layer, denoted by reference numerals 6b-05 and 6b-40, is responsible for compressing/decompressing IP headers. The main functions of the PDCP layer are summarized as follows:

header compression and decompression: ROHC only

-user data transfer

-encryption and decryption

Timer-based SDU discard in uplink

The RLC layer designated by reference numerals 6b-10 and 6b-35 is responsible for reformatting the PDCP PDUs so that they fit into the size of the ARQ operation. The main functions of the RLC protocol are summarized as follows:

-transmission of upper layer PDU

Error correction by ARQ (for AM data transfer only)

Re-segmentation of RLC data PDUs (for AM data transfer only)

Reordering of RLC data PDUs (for UM and AM data transfer only)

Duplicate detection (for UM and AM data transfer only)

Protocol error detection (for AM data transfer only)

RLC SDU discard (for UM and AM data transfer only)

RLC re-establishment

The MAC layer, denoted by reference numerals 6b-15 and 6b-30, allows establishing a connection of a plurality of RLC entities for one UE and is responsible for multiplexing RLC PDUs from the RLC layer into MAC PDUs and demultiplexing the MAC PDUs into RLC PDUs. The main functions of the MAC protocol are summarized as follows:

mapping between logical channels and transport channels

-multiplexing/demultiplexing MAC SDUs belonging to one or different logical channels into/from Transport Blocks (TBs) delivered from the physical layer on the transport channel

-scheduling information reporting

Error correction by HARQ

-priority handling between logical channels of one UE

-prioritization among UEs by dynamic scheduling

-MBMS service identification

-transport format selection

-filling

The PHY layers, denoted by reference numerals 6b-20 and 6b-25, are responsible for channel coding and modulating the higher layer data to generate and transmit OFDM symbols on a radio channel, and demodulating and channel decoding OFDM symbols received on the radio channel to deliver the decoded data to the higher layers.

Fig. 6C is a diagram illustrating an architecture of a next generation mobile communication system according to an embodiment of the present disclosure.

Referring to fig. 6C, the radio access network 6C-20 of the next generation mobile communication system includes a new radio Node B (RN NB) 6C-10 and a new radio core network (NR CN) 6C-05. The new radio user equipment (hereinafter referred to as NR UE or simply UE) 6c-15 is connected to the external network via NR NB 6c-10 and NR CN 6c-05.

In fig. 6C, the NR NB 6C-10 corresponds to an evolved Node B (eNB) in the conventional LTE system. The NR UEs 6c-15 are connected to a NR NB which can provide services better than legacy enbs. In the next generation mobile communication system in which all user traffic is served through a shared channel, an entity is required to collect UE-specific state information (such as buffer status, power headroom status, and channel status) and schedule UEs based on the collected information, and the NR NB 6c-10 is responsible for these functions. Typically, one NR NB carries multiple cells. In order to satisfy the higher data rate requirement than the conventional LTE, it is necessary to secure the maximum bandwidth wider than ever by employing advanced techniques such as Orthogonal Frequency Division Multiplexing (OFDM) as a radio access scheme and beamforming. Adaptive Modulation and Coding (AMC) techniques may be employed to determine the modulation scheme and channel coding rate to adapt to the channel conditions of the UE. The NR CN6c-05 is responsible for mobility management, bearer establishment and QoS establishment. The NR CN6c-05 is responsible for other control functions as well as UE mobility management functions related to multiple NR NBs. The next generation mobile communication system can interoperate with a conventional LTE system in such a manner that the NR CN6c-05 is connected to a Mobility Management Entity (MME) 6c-25 through a network interface. The MME 6c-25 is connected to the eNB 6c-30 which is a legacy base station.

Fig. 6D is a diagram illustrating a protocol stack of an interface between NR UE and NR gbb in a next generation mobile communication system according to an embodiment of the present disclosure.

Referring to fig. 6D, in the next generation mobile communication system, a protocol stack of an interface between the NR UE and the NR gNB includes a plurality of protocol layers stacked from bottom to top: the NR PHY layers denoted by reference numerals 6d-20 and 6d-25, the NR MAC layers denoted by reference numerals 6d-15 and 6d-30, the NR RLC layers denoted by reference numerals 6d-10 and 6d-35, and the NR PDCP layers denoted by reference numerals 6d-05 and 6 d-40. The main functions of the NR PDCP layer, denoted by reference numerals 6d-05 and 6d-40, may include some of the following functions:

header compression and decompression: ROHC only

-user data transfer

-sequential delivery of upper layer PDUs

-PDCP PDU reordering for reception

Duplicate detection of lower layer SDU

-retransmission of PDCP SDU

-encryption and decryption

Timer-based SDU discard in uplink

The PDCP PDU reordering function of the NR PDCP entity is to reorder PDCP PDUs delivered from a lower layer based on PDCP sequence numbers (PDCP SNs), and may include delivering reordered data to an upper layer, recording missing PDCP PDUs among the reordered PDCP PDUs, transmitting a status report indicating the missing PDCP PDUs to a transmitting side, and requesting retransmission of the missing PDCP PDUs.

The main functions of the NR RLC layer, denoted by reference numerals 6d-10 and 6d-35, may include some of the following functions.

-transmission of upper layer PDU

-sequential delivery of upper layer PDUs

Out-of-order delivery of upper layer PDUs

Error correction by ARQ

Concatenation, segmentation and reassembly of RLC SDUs

-re-segmentation of RLC data PDUs

Reordering of RLC data PDUs

-duplicate detection

-protocol error detection

RLC SDU discard

RLC re-establishment

The sequential delivery function of the NR RLC entity is to deliver RLC SDUs received from a lower layer to an upper layer, and may include: when receiving a plurality of segmented RLC SDUs constituting an original RLC SDU, reassembling the RLC SDUs and transferring the reassembling RLC SDUs to an upper layer; reordering the received RLC PDUs based on an RLC Sequence Number (SN) or a PDCP SN; recording the RLC PDU lost in the reordered RLC PDUs; sending a status report indicating the missing RLC PDUs to the sender; requesting retransmission of the missing RLC PDU; and sequentially delivering RLC PDUs prior to the missing RLC PDU to an upper layer when there is the missing RLC PDU, sequentially delivering all RLC PDUs received before the timer is started to the upper layer if the predetermined timer expires even though there is any missing RLC SDU, or sequentially delivering all RLC PDUs received until then to the upper layer if the predetermined timer expires even though there is any missing RLC SDU. RLC PDUs may also be processed in the order of reception (in order of arrival without regard to sequence numbers) and delivered out of order to the PDCP entity (out of order delivery) and, if the RLC PDUs are sent in segments, the received segments are stored or waiting until all segments constituting the RLC PDU are received and the segments are reassembled into the original RLC PDU, which is delivered to the PDCP entity. The NR RLC layer may have no concatenation function, and in this case, the concatenation function may be performed in the NR MAC layer or replaced by a multiplexing function of the NR MAC layer.

In the NR MAC layer denoted by reference numerals 6d-15 and 6d-30, a NR MAC entity may be connected to a plurality of NR RLC entities, and the main functions of the NR MAC entity may include some of the following functions:

mapping between logical channels and transport channels

-multiplexing/demultiplexing MAC SDU

-scheduling information reporting

Error correction by HARQ

-priority handling between logical channels of one UE

-prioritization among UEs by dynamic scheduling

-MBMS service identification

-transport format selection

-filling

The NR PHY layer, denoted by reference numerals 6d-20 and 6d-25, is responsible for channel coding and modulation of upper layer data to generate and transmit OFDM symbols on a radio channel, and demodulates and channel decodes OFDM symbols received on the radio channel to deliver the decoded data to the upper layer.

Fig. 6E is a diagram illustrating a Discontinuous Reception (DRX) operation of a UE in an idle mode in an LTE system according to an embodiment of the present disclosure.

Referring to FIG. 6E, each of the UEs 6E-10 and 6E-15 in idle mode monitors the PDCCH to receive a paging message from the eNB 6E-05. DRX, adopted as an efficient UE power saving technique in LTE, is characterized by: the DRX cycle is configured such that the receiver remains in a sleep mode during the "off" time and wakes up at predetermined intervals during the "on" time. For example, the paging cycle is configured so that the UE receives messages from the network 6e-05, as indicated by reference numerals 6e-25 and 6 e-30. If the UE (one of the UEs 6e-10 and 6 e-15) detects a paging RNTI (P-RNTI), it processes the corresponding downlink paging message. The paging message includes the UE ID so that other UEs having different UE IDs discard the received information and enter a sleep mode according to the DRX cycle. Since the UE does not know the DRX cycle, HARQ is not applied during the DRX cycle.

The network 6e-05 configures the subframe 6e-20 for paging the UE. The configuration is made based on the smallest one of the period Tue and the cell-specific period Tc requested by the UE. The paging cycle is set to one of 32, 64, 128 and 256 frames. Paging subframes 6e-20 within a frame may be identified based on an International Mobile Subscriber Identity (IMSI) of the UE. Since the UEs have different IMSIs, each UE operates according to the paging instance belonging to that UE among all paging occasions 63-35.

The paging message may be transmitted in a predetermined number of subframes 6e-20, which may be configured as shown in table 5.

[ Table 5]

Fig. 6F is a diagram illustrating a DRX operation of a UE in a Radio Resource Control (RRC) connected mode in an LTE system according to an embodiment of the present disclosure.

Referring to fig. 6F, DRX is also supported in the RRC connected mode, and the RRC connected mode operation is different from the RRC idle mode operation. Connected mode DRX is referred to as connected mode DRX (CDRX). As described above, if the UE continuously monitors the PDCCH for scheduling information, this will result in large power consumption. CDRX is configured with a DRX cycle 6f-00 having an on duration period 6f-05 in which the UE wakes up to perform PDCCH monitoring. CDRX may be configured with two DRX cycles, i.e., a long DRX cycle and a short DRX cycle. A long DRX cycle is typically configured and the eNB may trigger a short DRX cycle using MAC CE if needed. After a predetermined period of time, the UE switches from the short DRX cycle to the long DRX cycle. Initial scheduling information for a specific UE is provided in a predetermined PDCCH. Therefore, the UE monitors only the corresponding PDCCH candidate to minimize power consumption. If scheduling information of a new packet is received during the on duration period 6f-05, as shown by reference numeral 6f-10, the UE turns on a DRX inactivity timer, as shown by reference numeral 6 f-15. The UE remains in the active state while the DRX inactivity timer is running. For example, the UE continuously monitors the PDCCH. Further, the HARQ RTT timer is started, as indicated by reference numerals 6 f-20. The HARQ RTT timer is used to prevent the UE from unnecessarily performing PDCCH monitoring during a HARQ Round Trip Time (RTT), i.e., the UE does not have to perform PDCCH monitoring while the timer is running. However, when both the DRX inactivity timer and the HARQ RTT timer are running, the UE continuously monitors the PDCCH according to the DRX inactivity timer. If the HARQ RTT timer expires, the DRX retransmission timer is turned on, as shown at reference numerals 6 f-25. When the DRX retransmission timer is running, the UE must continuously monitor the PDCCH. Generally, when the DRX retransmission timer is running, scheduling information for HARQ retransmission is received, as shown by reference numerals 6 f-30. If the UE receives the scheduling information, it immediately stops the DRX retransmission timer and starts the HARQ RTT timer again. This operation is repeated until the packet is successfully received, as indicated by reference numerals 6 f-35.

The UE receives CDRX operation-related configuration information via an RRCConnectionReconfiguration message. Each of an on-duration (on-duration) timer, a DRX inactivity timer, and a DRX retransmission timer specifies the number of PDCCH subframes. The timer will expire if the number of PDCCH subframes for the timer passes. In FDD, all downlink subframes may transmit PDCCH; in TDD, downlink subframes and special subframes may convey PDCCH. In TDD, there are downlink, uplink, and special subframes in the same frequency band. Wherein the downlink subframe and the special subframe are considered as PDCCH subframes.

The eNB may configure two states, longDRX and shortDRX. In general, the eNB may remain in one of two states based on power preference indication information transmitted by the UE, UE mobility history information, and characteristics of the configured DRBs. The transition between these two states is triggered by the expiration of a predetermined timer or the receipt of a predetermined MAC CE.

Fig. 6G is a diagram illustrating a packet delay budget reporting operation for improving voice over LTE (VoLTE) quality in a wireless communication system according to an embodiment of the present disclosure.

In LTE, the recommended value of End-to-End (E2E) one-way delay time to meet current VoLTE QoS requirements is 150ms, with a tolerance of 40ms.

Referring to fig. 6G, when two UEs 6G-05 and 6G-10 use VoLTE service via the enbs 6G-15 and 6G-20 serving them, respectively, voLTE service quality may vary depending on the channel quality established with the eNB. It is likely that UE 1 3g-15 has good VoLTE quality, while UE2 3g-20 has poor VoLTE quality. The eNB may adjust the CDRX period of the UE according to the aforementioned one-way packet delay time, and may adjust the repetition transmission period of the UE, particularly for MTC UEs. In general, when channel conditions between an eNB and a UE are good, the eNB configures CDRX for the corresponding UE to reduce unnecessary power consumption. However, if the channel condition between the eNB and the UE is poor, the eNB does not configure CDRX for the corresponding UE. The embodiment of figure 6G is for CDRX reconfiguration request operations where UE 1 6G-05 and UE 2G-10 are experiencing poor VoLTE quality of service (see table 6).

[ Table 6]

As summarized in table 6, if the channel conditions between UE 1 6g-05 and eNB 2 6g-15 are good and the channel conditions between UE2 6g-10 and eNB 2 6g-20 are poor, while the VoLTE quality is poor at both UE 1 6g-05 and UE2 6g-10, it is likely that CDRX is configured for UE 1 6g-05 instead of UE2 6g-10. However, CDRX operations associated with UE 1 6g-05 may result in further degradation of VoLTE communication performance with UE2 6g-10, which affects packet reception failures at UE2 6g-20 during sleep of its CDRX. If UE 1 6g-05 knows the E2E one-way delay time with eNB 2 6g-20, it can calculate its allowable delay value and the requested CDRX period value based on the corresponding delay time and the serving eNB configured CDRX period. For example, the allowable E2E delay may be calculated by the following equation.

Allowed E2E delay = E2E delay margin (400 ms) — measured E2E delay

For example, assuming an E2E delay requirement (delay margin) of 400ms and a UE measured E2E delay of 200ms, the UE allows an additional delay of 200 ms. If UE 1 6g-05 is currently configured with a CDRX period of 160ms, it may adjust the configured CDRX period value to improve VoLTE performance or increase the CDRX period to save power. The measured E2E delay time may be considered as the sum of the configured CDRX period value and the packet transmission delay on the wireless and wired channels, and the maximum value of CDRX period change may be 100ms (allowable E2E delay value/2). This is the case when the channels of both UE 1 6g-05 and UE2 6g-10 are considered by paying attention to the operation of other UEs, the values can be changed accurately. For example, if the CDRX period value decreases, the UE may receive packets more frequently, thereby improving VoLTE performance. The CDRX cycle change value that the UE may request may be configured according to an embodiment of the UE based on the allowable E2E delay value. Since the eNB and the network know the exact value of the E2E transmission delay value measured by the UE, the corresponding operation may be triggered by the UE. For example, for delay budget reporting, the UE may request a CDRX period value of Y ms as the change target value according to the UE measured E2E transmission delay value instead of the previously configured CDRX period value. Upon receiving the request message, the eNB reconfigures the previously configured CDRX cycle.

Fig. 6H is a diagram illustrating a packet transmission delay measurement method of an item in the VoLTE system according to an embodiment of the present disclosure.

Referring to fig. 6H, as briefly described with reference to fig. 6G, since the eNB and the network cannot measure the one-way packet delay time between UEs, the one-way packet delay time between UEs cannot be known unless the UEs report accurate packet delay measurements. During VoLTE service, the UE may transmit data in Real Time Protocol (RTP) packets and measure E2E delay Time by transmitting and receiving Real Time Control Protocol (RTCP) packets. Part (a) of fig. 6H depicts a sender report format of an RTCP packet; the Last Sender Report (LSR) and the Delay since the LSR (Delay sequence LSR) in the Sender Report format may be used to measure E2E packet Delay time. For example, the one-way E2E delay time depicted in part (B) of fig. 6H may be calculated using the following equation.

Unidirectional E2E delay = ((time a-time LSR) -DLSR)/2

This method is only an example, and the packet transmission delay time between UEs can be calculated in various methods. The reason for dividing the numerator by 2 is that the sender can measure the E2E delay time based on the round trip time, i.e. E2E is half the round trip time.

Fig. 6I is a signal flow diagram illustrating a method for a UE to request a CDRX cycle change and to transmit and receive data with the changed CDRX cycle, according to an embodiment of the present disclosure.

Referring to fig. 6I, the procedure described with reference to fig. 6I is applicable to both LTE and next generation mobile communication systems.

UE 1 and UE2 in RRC connected mode are connected to gNB 1 and gNB 2, respectively, to transmit and receive voice data through the VoLTE service. This embodiment is directed to VoLTE service related procedures in which the UE measures the E2E delay time and requests a change of CDRX cycle to reconfigure the DRX cycle to improve VoLTE service quality. However, the present disclosure is not limited to VoLTE services (i.e., voice data services), but may be applied to other types of services in the same manner.

At operation 6i-05, UE 1 connected to eNB 1 and UE2 connected to eNB 2 are performing a voice call over VoLTE service. VoLTE data communication may be performed with RTP packets, and in this case, at operation 6i-10, the UE may send and receive RTCP packets and measure the round trip time of the packets by decoding corresponding field values in the RTCP packets (as described with reference to fig. 6H). At operations 6i-15 and 6i-20, UE 1 and UE2 may measure a one-way transmission delay time for E2E delay measurement based on the signal transmitted at operation 6 i-10. For example, the one-way E2E delay time may be obtained by dividing the packet round trip time measured at operations 6i-10 by 2. Although this embodiment includes all operations of UE 1 and UE2, each UE operates independently. For example, the same operations may be performed by one or both of UE 1 and UE 2. Further, the same operation may be performed by UE 1 and UE2 at different timings.

At operations 6i-25 and 6i-30, UE 1 and UE2 may request a change in CDRX cycle or repeat transmission cycle of the eMTC UE based on the measured one-way transmission delay time and a predetermined required E2E delay requirement time margin value to improve VoLTE quality. In this embodiment of the present disclosure, the DRX cycle change is performed in such a way that the UE sends a DRX cycle change request to the corresponding gNB via a delayed budget request. At operations 6i-35 and 6i-40, the delayed budget request may be transmitted in an RRC message (i.e., UEAssistant information). The UEAssistanceInformation is generated in the format shown in table 7. Here, the DRX cycle change request corresponds to a type 1 field value of delaybidgetreport-14 IE, and the UE sets the type 1 field to a change target DRX cycle value.

[ Table 7]

UEAssistanceInformation message

In this operation, there may be various options to select the DRX cycle as a reference.

1. Option 1: long DRX cycle of MCG (Master Cell Group)

Applying the long DRX period value set for MCG

2. Option 2: short DRX cycle of MCG

Applying the short DRX period value set for MCG

3. Option 3: actual DRX cycle of MCG (Long DRX cycle or short DRX cycle currently applied)

-applying the currently set DRX cycle value (long DRX or short DRX) for the MCG.

4. Option 4: if the short DRX cycle is configured for the MCG, the short DRX cycle of the MCG. Otherwise, long DRX cycle of MCG

-applying a short DRX cycle value of MCG if the short DRX cycle is set for MCG

5. Option 5: delayBudgetreport indicates which DRX cycle should be adjusted

-DelayBudgetReport indicating the DRX value to apply

At operations 6i-45 and 6i-50, eNB 1 and eNB 2 reconfigure the DRX cycle based on the DRX cycle change request signal received from the UEs (UE 1 and UE 2). The eNB may reconfigure the DRX cycle as requested via a DRX cycle change request included in an RRC report message from the UE, or according to its own determination or eNB implementation. At operations 6i-55 and 6i-60, the eNB sends an RRC message to the UE including the reconfigured DRX cycle value. Thereafter, the UE 1 and the UE2 continue to perform service (VoLTE or another data communication) according to the reconfigured DRX cycle, and perform the E2E delay time measurement operation at operation 6i-65, as at operation 6i-65, if the currently required DRX change value calculated based on the one-way packet delay time measured by the UE is different from the previously requested DRX cycle, the DRX change request operation of operations 6i-25 to 6i-60 is triggered.

Fig. 6J is a flowchart illustrating a CDRX period change procedure of a UE according to an embodiment of the present disclosure.

Referring to fig. 6J, at operation 6J-05, a UE in connected mode measures a one-way E2E delay. The one-way E2E delay can be measured in various ways, e.g., sending/receiving RTP packets, in particular RTCP packets; in case of using the RTCP packet, the UE decodes a specific field configured for E2E delay measurement in the RTCP packet, measures a round trip time of a packet transmitted by a sender, and measures a one-way D2D delay based on the measurement result. At operation 6j-10, the UE determines to change the CDRX period based on the measured unidirectional E2E delay and a predetermined E2E delay requirement (which may be predetermined according to time margin and QoS). For example, if the currently configured DRX cycle is too long or too short to match the E2E delay requirement, data transmission/reception performance may be achieved by adjusting the DRX cycle. For example, in the case where VoLTE quality is poor for a UE using VoLTE services and if the measured E2E value is greater than the E22 delay requirement, the UE may request that the CDRX period value be decreased to achieve an improvement in VoLTE quality and meet the E2E delay requirement. For reference, CDRX cycle values and E2E delays are correlated, so if the DRX cycle is reduced, the E2E delay is also reduced. This is because the E2E delay should be longer than the CDRX period because there is no data transmission/reception during the CDRX period. Otherwise, if the VoLTE quality of the UE is good and if the measured E2E delay value is less than the E2E delay requirement, the UE may request an increase of the CDRX period value to achieve the power saving gain of the UE.

At operation 6j-15, the UE triggers a delay budget report and generates a delay budget report message including the changed UE expected CDRX period values determined in the previous operation. Here, the DRX cycle change request may correspond to a type 1 field value of delaybidgetreport-14 IE in a UEAssistanceInformation message as RRC signaling, the type 1 field being configured with a DRX cycle value that the UE requests to change. The corresponding information may be transmitted via other RRC messages or MAC CEs.

At operation 6j-20, the UE receives an RRC message (RRCConnectionReconfiguration) from the gNB and reconfigures the DRX cycle. At operation 6j-25, the UE compares the currently reconfigured preferred DRX cycle value with the previously reported DRX cycle value to perform the first operation if the two values are identical to each other and to perform the second operation if the two values are different from each other. In the first operation of operations 6j-30, the UE maintains the current configuration and transmits/receives data; in a second operation of operations 6j-35, the UE triggers a delay budget report to re-request the UE's desired CDRX period value through RRC signaling. This means that operations 6j-10 to 6j-20 are repeated.

Fig. 6K is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure.

Referring to FIG. 6K, the UE includes a Radio Frequency (RF) processor 6k-10, a baseband processor 6k-20, a memory unit 6k-30, and a controller 6k-40.

The RF processors 6k-10 have functions of transmitting/receiving signals through radio channels, such as band conversion and amplification of the signals. For example, the RF processors 6k-10 up-convert baseband signals from the baseband processors 6k-20 to RF band signals and transmit the RF signals via the antennas and down-convert RF signals received via the antennas to baseband signals. For example, the RF processors 6k-10 may include transmit filters, receive filters, amplifiers, mixers, oscillators, DACs, and ADCs. Although one antenna is depicted in the drawing, the UE may be equipped with multiple antennas. The RF processor 6k-10 may also comprise a plurality of RF chains. The RF processors 6k-10 may perform beamforming. For beamforming, the RF processors 6k-10 may adjust the phase and magnitude of the signals to be transmitted/received in phase and magnitude through the antennas or antenna elements. The RF processors 5i-10 may be configured to support a MIMO scheme by which the UE can receive multiple layers simultaneously.

The baseband processor 6k-20 has a baseband signal-to-bit string conversion function according to the system physical layer standard. For example, in the data transmission mode, the baseband processor 6k-20 performs coding and modulation on the transmission bit string to generate complex symbols. In the data reception mode, the baseband processor 6k-20 performs demodulation and decoding on the baseband signal from the RF processor 6k-10 to recover the transmitted bit string. In the case of using the OFDM scheme for data transmission, the baseband processors 6k-20 perform coding and modulation on a transmission bit string to generate complex symbols, map the complex symbols to subcarriers, perform IFFT on the symbols, and insert CPs into the symbols to generate OFDM symbols. In the data reception mode, the baseband processor 6k-20 divides the baseband signal from the RF processor 6k-10 into OFDM symbols, performs FFT on the OFDM symbols to recover the signal mapped to the subcarriers, and performs demodulation and decoding on the signal to recover the transmitted bit string.

The baseband processor 6k-20 and the RF processor 6k-10 process the transmission and reception signals as described above. The baseband processor 6k-20 and the RF processor 6k-10 may thus be referred to as transmitters, receivers, transceivers or communication units. At least one of the baseband processor 6k-20 and the RF processor 6k-10 may comprise a plurality of communication modules for supporting different radio access technologies. At least one of the baseband processor 6k-20 and the RF processor 6k-10 may further comprise a plurality of communication modules for processing signals in different frequency bands. For example, different radio access technologies may include Wireless Local Area Networks (WLANs) (e.g., institute of Electrical and Electronics Engineers (IEEE) 802.11) and cellular networks (e.g., LTE). The different frequency bands may include the ultra high frequency (SHF) band (e.g., 2.5GHz and 5GHz bands) and the mmWave band (e.g., 60 GHz).

The memory units 6k-30 store data such as basic programs for operating the UE, application programs, and setting information. The memory units 6k-30 may also store information about a second access node utilizing a second radio access technology for radio communication. The storage unit 6k-30 provides the stored information in response to a request from the controller 6k-40.

The controller 6k-40 controls the overall operation of the UE. For example, the controller 6k-40 controls the baseband processor 6k-20 and the RF processor 6k-10 to transmit and receive signals. The controller 6k-40 writes data to the memory unit 6k-30 and reads data from the memory unit 6 k-30. To this end, the controller 6k-40 may include at least one processor. For example, the controllers 6k-40 may include a CP for controlling communications and an AP for controlling higher layer programs (such as applications). The controller 6k-40 may include a multi-connection processor 6k-42 for processing operations in a multi-connection mode.

Fig. 6L is a block diagram illustrating a configuration of a gNB according to an embodiment of the present disclosure.

Referring to FIG. 6L, the gNB includes RF processors 6l-10, baseband processors 6l-20, backhaul communication units 6l-30, memory units 6l-40, and controllers 6l-50.

The RF processors 6l-10 have functions of transmitting/receiving signals through radio channels, such as band conversion and amplification of the signals. For example, the RF processors 6l-10 up-convert baseband signals from the baseband processors 6l-20 into RF band signals, and transmit the RF signals via an antenna, and down-convert RF signals received via the antenna into baseband signals. For example, the RF processors 6l-10 may include transmit filters, receive filters, amplifiers, mixers, oscillators, DACs, and ADCs. Although one antenna is depicted in the drawing, the gbb may be equipped with multiple antennas. The RF processors 6l-10 may also comprise a plurality of RF chains. The RF processors 6l-10 may perform beamforming. For beamforming, the RF processors 6l-10 may adjust the phase and magnitude of signals to be transmitted/received through the antenna or antenna elements. The RF processors 6l-10 may be configured to transmit one or more layers of downlink MIMO operation.

The baseband processors 6l-20 have a baseband signal-to-bit string conversion function according to the system physical layer standard. For example, in the data transmission mode, the baseband processors 6l to 20 perform coding and modulation on the transmission bit string to generate complex symbols. In the data reception mode, the baseband processors 6l-20 perform demodulation and decoding on the baseband signals from the RF processors 6l-10 to recover the transmitted bit strings. In the case of using the OFDM scheme for data transmission, the baseband processors 6l to 20 perform coding and modulation on a transmission bit string to generate complex symbols, map the complex symbols to subcarriers, perform IFFT on the symbols, and insert CPs into the symbols to generate OFDM symbols. In the data reception mode, the baseband processors 6l-20 divide the baseband signal from the RF processors 6l-10 into OFDM symbols, perform Fast Fourier Transform (FFT) on the OFDM symbols to recover the signals mapped to the subcarriers, and perform demodulation and decoding on the signals to recover the transmitted bit string. The baseband processor 6l-20 and the RF processor 6l-10 process the transmission and reception signals as described above. The baseband processors 6l-20 and the RF processors 6l-10 may thus be referred to as transmitters, receivers, transceivers or communication units.

The backhaul communication units 6l-30 provide interfaces for communicating with other nodes in the network. For example, the backhaul communication units 6l-30 convert a bit string to be transmitted from the gNB to another node (e.g., another gNB and a core network) into a physical signal, and convert a physical signal received from another node into a bit string.

The storage units 6l-40 store data such as basic programs, application programs, and setting information for the operation of the gNB. The memory units 6l-40 may also store information about bearers established for the UE and measurement results reported by the connected UE. The memory units 6l-40 may also store information for use by the UE in determining whether to enable or disable the multi-connection. The storage units 6l-40 may provide the stored data with reference to a request from the controllers 6l-50.

Controllers 6l-50 control the overall operation of the gNB. For example, the controllers 6l-50 control the baseband processors 6l-20, the RF processors 6l-10, and the backhaul communication units 6l-30 for transmitting and receiving signals. The controllers 6l-50 read and write data to the memory units 6 l-40. To this end, the controllers 6l-50 may comprise at least one processor. The controllers 6l-50 may also include a multi-connection processor 6l-52 for processing operations in a multi-connection mode.

The sixth embodiment of the present disclosure can be summarized as follows.

Problem 1: which DRX cycle?

delayBudgetAdjustment

The parameter indicates a preferred increment/decrement relative to the current configuration. The parameter has a millisecond value. For example, ms40 corresponds to 40 milliseconds, msMinus40 corresponds to-40 milliseconds, and so on.

As described above, the UE reports a preferred DRX cycle relative to the current DRX cycle. The question is which DRX cycle is the current DRX cycle. Whether it is an MCG DRX cycle or an SCG DRX cycle, or whether it is a short DRX cycle or a long DRX cycle.

Possible options

Option 1: long DRX cycle for MCG

Option 2: short DRX cycle of MCG

Option 3: actual DRX cycle of MCG (Long DRX cycle or short DRX cycle currently applied)

Option 4: and if the short DRX period is configured for the MCG, the short DRX period of the MCG.

Otherwise, long DRX cycle of MCG

Option 5: delayBudgetRoport indicates which DRX cycle should be adjusted

(option 1

Option 2: short DRX cycle of MCG

Option 4: if the short DRX cycle is configured for the MCG, the short DRX cycle of the MCG.

Otherwise, long DRX cycle of MCG

Option 5: delayBudgetreport indicates which DRX cycle should be adjusted)

Problem 2: unnecessary reporting due to a change of a current DRX period

This embodiment addresses the case where the UE retransmits the delay budget report if the current delaybidgetadjustment is different from what was reported. However, the delaybudtagedjustment may vary due to a change in the reference value (current DRX cycle), rather than a change in the UE preference.

The comparison should be made between the current preference and the reported preference.

(problem 2: unnecessary reporting due to current DRX cycle change

In the current specification, the UE retransmits the delay budget report if the current delaybudgetadjustine is different from that reported.

But the delayBudgetAdjustment may become different not because the user preference changes but because the reference value (i.e., the current DRX cycle) changes

The comparison should be between the current preference and the reported preference. The text can be updated as follows)

Seventh embodiment

Fig. 7A is a diagram illustrating an architecture of a next generation mobile communication system according to an embodiment of the present disclosure.

Referring to fig. 7A, the radio access network of the next generation mobile communication system includes a new radio Node B (gNB) 7A-10 and a new radio core network (AMF) 7A-05. The new radio user equipment (hereinafter NR UE or simply UE) 7a-15 is connected to the external network via the gNB 7a-10 and AMF 7a-05.

In fig. 7A, the gnbs 7A-10 correspond to evolved Node bs (enbs) in a conventional LTE system. The NR UEs 7a-15 are connected to a gNB which can provide services better than legacy enbs. In a next generation mobile communication system in which all user traffic is served through a shared channel, an entity is required to collect UE-specific status information (such as buffer status, power headroom status, and channel status) and schedule UEs based on the collected information, and the gnbs 7a-10 are responsible for these functions. Typically, one gNB carries multiple cells. In order to satisfy the higher data rate requirement than the conventional LTE, it is necessary to secure the maximum bandwidth wider than ever by employing advanced techniques such as Orthogonal Frequency Division Multiplexing (OFDM) as a radio access scheme and beamforming. Adaptive Modulation and Coding (AMC) techniques may be employed to determine the modulation scheme and channel coding rate to adapt to the channel conditions of the UE. The AMFs 7a-05 are responsible for mobility management, bearer establishment and QoS establishment. The AMFs 7a-05 are responsible for other control functions as well as UE mobility management functions related to multiple gnbs. The next generation mobile communication system may interoperate with a conventional LTE system in such a manner that the AMF 7a-05 is connected to a Mobility Management Entity (MME) 7a-25 through a network interface. The MME 7a-25 is connected to the eNBs 7a-30 as legacy base stations. A UE supporting LTE-NR dual connectivity may establish a connection to enbs 7a-30, as indicated by reference numerals 7a-35, and to gnbs 7a-10, as indicated by reference numerals 7 a-20.

Fig. 7B is a diagram illustrating a method for determining whether to accept access in a legacy LTE system according to an embodiment of the present disclosure.

Referring to fig. 7b, the functionality of an lte UE is divided into an Access Stratum (AS) 7b-15 and a non-access stratum (NAS) 7b-20. The AS is responsible for all access related functions and the NAS 7b-05 is responsible for non-access related functions such AS Public Land Mobile Network (PLMN) selection and service requests. The accessibility determination may be primarily determined by the UE AS. As mentioned above, a network in congestion may restrict new accesses and for this purpose it broadcasts relevant configuration information for each UE to make its own access determination, as indicated by reference numerals 7 b-35. With the introduction of new requirements in legacy LTE systems, new barring mechanisms have been proposed, as a result of which multiple access barring checks are allowed. If the UE NAS layer issues a service request, AS indicated by reference numeral 7b-10, the UE AS checks if the UE can actually access the network. If the establishment cause value of the service request is "delay tolerant access", the UE AS first performs Extended Access Barring (EAB), AS indicated by reference numerals 7b-20. The EAB barring mechanism is performed as an access check procedure applicable only to Machine Type Communication (MTC). If the EAB check is passed, the UE AS performs dedicated congestion control for data communication (ACDC) 7b-55, AS indicated by reference numerals 7b-20. The application requesting the service is assigned an ACDC category, the value of which may be included in the service request transmitted to the UE AS. The network may provide barring configuration information for each ACDC category. Thus, the access checking procedure may be performed per group, which groups are classified by ACDC categories. If the barring configuration information for each ACDC category is not provided by the network, the UE AS omits the ACDC access checking procedure. If the ACDC check is passed, the UE AS performs Access Class Barring (ACB), AS indicated by reference numerals 7 b-30. The ACB is an access check procedure using barring configuration information separately provided according to Mobile Originating (MO) data or MO signaling. For multi-way telephony (MMTEL) voice/video/SMS services, the ACB procedure may be omitted using an ACB skip indicator, as shown at reference numerals 7 b-25. The UE AS may attempt to access the network if all of the above access checking procedures are passed. For example, the UE AS performs random access and sends a Radio Resource Control (RRC) connection request message to the eNB, AS indicated by reference numerals 7 b-40. There may be another access check procedure that is not performed by the UE AS. If barring configuration information (SSAC) of MMTEL voice/video is received from the network, AS indicated by reference numerals 7b-45, the UE AS transfers this information to the IMS layer responsible for managing the services in the UE, AS indicated by reference numerals 7 b-50. After receiving the barring configuration information, the IMS layer may perform an access check procedure when the service is triggered. SSAC, when introduced, is designed to cause the UE AS to perform the corresponding functions, regardless of the type of application or service. Therefore, in order to control the determination as to whether to accept access to a specific service (such as MMTEL voice/video), it is necessary to directly transfer the barring configuration information to a layer managing the service so that the corresponding layer performs an access check procedure.

Fig. 7C is a diagram illustrating a process for performing ACDC operation in an LTE system according to an embodiment of the disclosure.

Referring to fig. 7C, in an LTE system, ACDC has been proposed to make accessibility determination for each application (service). Each application is assigned at least one ACDC category value. ACDC category values are selected in the range of 1 to 16. At operation 7c-25, the network 7c-20 provides the ACDC category information per application to the UE NAS 7c-10 using NAS messages. At operation 7c-50, network 7c-20 provides the UE AS 7c-15 with barring configuration information to be applied to each ACDC category using System information Block 2 (SIB 2). The barring configuration information includes an ac-BarringFactor Information Element (IE) and an ac-Barringtime IE. The value of the ac-BarringFactor alpha is within the range of more than or equal to 0 and less than or equal to 1. UE AS 7c-15 extracts random values of rand within the range of more than or equal to 0 and less than or equal to rand < 1; if the random value is less than ac-BarringFactor, then access is assumed not to be barred, and if not, then access is assumed to be barred. If it is determined that access is barred, the UE AS 7c-15 delays the access attempt for a duration based on the following equation.

Equation of

"Tbarring" (0.7 +0.6 + rand). Ac-BarringTime. If a service request is triggered, at operation 7c-30 the UE AS 7c-15 extracts the ACDC category value for the application corresponding to the service. At operation 7c-35, the UE NAS 7c-10 sends a service request including the ACDC category value to the UE AS7 c-15. Upon receiving the service request, at operation 7c-40, the UE AS 7c-15 determines whether access is accepted according to the ACDC category value based on ACDC barring configuration information included in SIB 2. If SIB2 does not include the barring configuration information corresponding to the ACDC category, then it is assumed that applications belonging to the ACDC category are allowed access during ACDC. If access is allowed by the access barring check procedure, the UE AS 7c-15 sends an RRC connection request for random access to the network at operation 7 c-45.

Fig. 7D is a diagram illustrating a structure of ACDC configuration information used in a conventional LTE system according to an embodiment of the present disclosure.

Referring to fig. 7d, ACDC configuration information (ACDC-BarringForCommon-r 13) 7d-10 may provide PLMN-specific forbidden configuration information sets (ACDC-BarringPerPLMN 1, ACDC-BarringPerPLMN 2.) -7 d-35 and 7d-40. If all PLMNs have the same barring configuration information set, one barring configuration information set (ACDC-BarringForCommon-r 13) 7d-05 may be set most widely. The PLMN-specific barring configuration information or the set of common barring configuration information comprises category-specific barring configuration information 7d-20, 7d-25 and 7d-30. As described above, the disabling configuration information 7d-45 includes the ac-BarringFactor IE and the ac-Barringtime IE. If there is no barring configuration information for a particular ACDC category, then it is assumed that applications belonging to the respective ACDC category are not barred by ACDC.

Fig. 7E is a diagram illustrating a process for controlling access of a UE in a connected mode or an inactive mode according to an embodiment of the present disclosure.

Referring to fig. 7E, the present disclosure proposes a method of controlling access based on access identity and access category as in conventional ACDC. The access identity is an indication information defined in the 3GPP standard, i.e. specified explicitly in the standard document. The access identity is used to indicate one of several access types, as shown in table 8. It mainly indicates access types classified into access classes 11 to 15 and Multimedia Priority Service (MPS) and dedicated service (task-critical service (MCS)) with high priority. The access classes 11 to 15 indicate operator private or public purpose access.

[ Table 8]

The access categories are divided into two categories. One of these two categories is the standardized access category. The category is defined at the RAN level, i.e. is explicitly classified in standard documents. Thus, the same standardized access category is applicable for different operators. In the present disclosure, the emergency related category belongs to the standard access category. Each access belongs to at least one standardized access category. The other is a non-standardized access category. This category is defined outside of the third generation partnership project (3 GPP) architecture and is therefore not explicitly classified in standard documents. Thus, operators have their own operator-specific access categories that have different meanings. This is the same characteristic of the categories in a traditional ACDC. However, a particular access triggered by the UE NAS may not be mapped to a non-standardized access category. The proposed access control scheme differs from conventional ACDC in that the classification is made using other elements and applications, such as service access type, call type, UE class, user group, signaling type, slice type, and any combination thereof. For example, access control may be performed for certain element-specific access types. The above access categories are used to indicate specific accesses, as shown in table 9. The access categories 0 to 7 are used to indicate standardized access categories and the access categories 32 to 63 are used to indicate operator specific access categories.

[ Table 9]

The operator's server 7e-25 provides operator specific access category information MO to the UE NAS1e-10 via NAS signaling or application layer data transmission. The above information indicates a certain element, such as an application, corresponding thereto. For example, the above information may explicitly indicate that the access category 32 corresponds to Facebook (Facebook) application access. The gNB 7e-20 uses the system information to provide the UE with a list of categories containing barring configuration information and the barring configuration information per category. The UE 7e-05 includes logical blocks of the NAS7e-10 and the AS7 e-15.

The UE NAS7e-10 maps the triggered accesses to one or more access identities and one access class according to predetermined rules. The mapping operation is performed in all RRC states, i.e. connected mode (RRC _ connected), IDLE mode (RRC _ IDLE) and INACTIVE mode (RRC _ INACTIVE). The features of the RRC state are as follows.

RRC_IDLE：

UE-specific DRX may be configured by upper layers;

-UE controlled mobility based on network configuration;

-UE：

-monitoring a paging channel;

-performing neighbor cell measurements and cell (re) selection;

-obtaining system information.

RRC_INACTIVE：

UE-specific DRX may be configured by upper layers or RRC layers;

-UE controlled mobility based on network configuration;

-the UE storing the AS context;

-UE：

-monitoring a paging channel;

-performing neighbor cell measurements and cell (re) selection;

-performing a RAN-based notification area update when moving out of the RAN-based notification area;

-obtaining system information.

RRC_CONNECTED：

-the UE storing the AS context.

-transmitting unicast data to/from the UE.

On the lower layer, the UE may be configured with UE-specific DRX;

-for CA-capable UEs, increasing bandwidth using one or more scells aggregated with the SpCell;

-for a UE supporting DC, increasing bandwidth using one SCG aggregated with MCGs;

network controlled mobility, i.e. handover within NR and to/from E-UTRAN.

-UE：

-monitoring a paging channel;

-monitoring a control channel associated with the shared data channel to determine whether data is scheduled for it;

-providing channel quality and feedback information;

-performing neighbor cell measurements and measurement reporting;

-obtaining system information.

Alternatively, the access may be mapped to a standardized access category and, additionally, to an operator specific access category. The UE NAS7e-10 sends the mapped access identity and access category and the service request to the UE AS7 e-15.

In this embodiment of the present disclosure, if in any of all RRS states, the UE AS 7e-15 receives a message from the UE NAS7e-10 including an access identity or access category information, it performs a barring check operation to determine whether the corresponding access is allowed before attempting the radio access triggered by the corresponding message. If it is determined by the barring check operation that radio access is allowed, the UE AS 7e-15 requests RRC connection establishment from the network. For example, in connected mode or inactive mode, at operation 7e-30 the UE NAS7e-10 sends an access identity and access category to the UE AS 7e-15 for the following reasons. In the present disclosure, the following reasons are collectively referred to as "new session request".

New MMTEL voice or video session

Sending SMS (SMS over IP or SMS over NAS)

-new PDU session establishment

-existing PDU session modification

-service request to re-establish user plane for existing PDU session

However, in idle mode, the UE NAS7e-10 sends the access identity and access category to the UE AS 7e-15 via a service request.

The UE AS 7e-15 determines whether to allow the access triggered by the UE NAS7e-10 based on the barring configuration information (barring check).

Fig. 7F is a signal flow diagram illustrating an access control procedure for a UE in a connected mode or an inactive mode according to an embodiment of the present disclosure.

Reference to FIG. 7F, UE 7f-05 includes NAS7f-10 and AS 7f-15. The NAS is responsible for operations not directly related to radio access, such AS authentication service requests and session management, while the AS 7f-15 is responsible for radio access related operations. At operation 7f-25, the network 7f-20 provides the MOI to the NAS7f-10 via OAM (application layer data message) or NAS message. The MOI indicates elements, such as applications, corresponding to each operator-specific access category. In order to identify the operator specific category to which the triggered access is mapped, the NAS7f-10 uses an MOI. The triggered access corresponds to a new MMTEL service (voice communication and video communication), SMS transmission, new PDU session establishment, previous PDU session change, etc. If the service is triggered, the NAS7f-10 maps the access identities corresponding to the attributes of the service to access categories at operation 7 f-30. Services may be mapped to no (none) or at least one access identity. Services may be mapped to access categories. Under the assumption that a service can be mapped to one access class, the NAS7f-10 determines whether the service is mapped to an operator-specific access class provided in the MO. If the service is not mapped to any operator specific access category, the NAS7f-10 maps the service to one of the available standardized access categories. The NAS7f-10 maps services to operator specific access classes and standardized access classes under the assumption that services can be mapped to multiple access classes. However, the service is not mapped to any operator specific access category, and the NAS7f-10 maps the service to one of the available standardized access categories. The mapping rule may be applied in addition to emergency services. At operation 7f-40, the NAS7f-10 sends a new session request or service request message to the AS 7f-15 including the mapped access identities and access categories. The NAS7f-10 transmits new session requests in connected mode or inactive mode and service requests in idle mode. At operation 7f-35, the AS 7f-15 receives barring configuration information included in the system information broadcast by the network 7 f-20. The prohibition configuration information is described below. At operation 7f-45, the AS determines whether the service request is accepted based on the access identity and access category information that the NAS has mapped to the service and corresponding mapping configuration information received from the network 7 f-20. If the service request is accepted according to the predetermined rule, the AS 7f-15 requests RRC connection establishment (RRC connection establishment or RRC connection restoration) from the network 7f-20 or sends data related to the new session to the network 7f-20 at operation 7 f-50.

Fig. 7G is a flowchart illustrating an operation of the UE NAS according to an embodiment of the present disclosure.

Referring to fig. 7G, at operation 7G-05, the UE NAS receives the MOI from the network through OAM or RRC signaling. The MOI indicates an element, such as "application" corresponding to each operator-specific access category.

At operation 7g-10, the UE NAS detects one of the following reasons.

-access attempt

New MMTEL voice or video session

Sending SMS (SMS over IP or SMS over NAS)

-new PDU session establishment

-existing PDU session modification

-service request to re-establish user plane for existing PDU session

At operation 7g-15, the UE NAS maps the access attempt to at least one access identity and access category. There may not be any corresponding access identities.

At operation 7g-20, the UE NAS sends a new session request/session modification (session management) or service request including mapped access identity and access category information to the UE AS.

FIG. 7H is a flowchart illustrating the operation of a UE AS according to an embodiment of the present invention.

Referring to fig. 7H, at operation 7H-05, the UE AS receives barring configuration information from the network via system information. The barring configuration information is provided per access identity and access category.

At operation 7h-10, the UE AS determines whether an access identity or access category is received from the UE NAS via a new session request/session modification (session management) or service request. A new session request/session modification (session management) or service request triggers the data transfer for RRC connection establishment or RRC connection recovery or a new session.

If an access identity and access category are received from the UE NAS via a new session request/session modification (session management) or service request, the UE AS performs a barring check based on the configuration information corresponding to the access identity and access category in the barring configuration information at operation 7 h-15. Here, the barring check is performed regardless of the current RRC state of the UE.

If neither an access identity nor an access category is received from the UE NAS via a new session request/session modification (session management) or service request, the UE AS does not perform a barring check on any data transmission at operation 7 h-20. For example, the UE AS does not perform any barring checks on initial data transmission and RRC connection recovery not involved by the NAS.

In this operation, the UE AS performs a barring check only on accesses for which the UE NAS provides an access identity and an access category. At the same time, there may be accesses triggered by the AS (without involvement of the NAS). No barring check is performed for this access. This may lead to network congestion if the AS triggered access is dominant. Therefore, additional barring checks may need to be made for AS triggered accesses. One approach is for the AS to perform a separate barring check on AS triggered accesses. AS triggered accesses may be classified by attribute. For example, AS-triggered access may fall into one of two types: MO signaling or MO data. The network provides forbidden configuration information per category applied in connected mode or inactive mode. The barring configuration corresponding to each type of access identity or access category may be reused. According to an embodiment of the present disclosure, if a RAN area update is triggered while the UE is in an inactive state, the RAN area update falls into MO signaling. The UE AS performs barring checks using barring configuration information corresponding to MO signaling. Here, the barring configuration information corresponding to access category 3 may be reused for barring checking.

The present disclosure relates to a barring check procedure performed based on an access identity and an access category. The barring check procedure is applicable to UEs in idle mode as well as in connected mode.

The UE NAS maps the access to one or more access identities and one access class and sends the mapping to the UE AS. If the access identity is set to 0, then no other mapped access identities may be assumed.

The UE AS determines if there is one received access identity and if so, the access identity is set to 0.

If at least one access identity is set to a non-zero value, the UE AS performs a barring check based on the non-zero access identity. The UE AS performs barring checks based on barring configuration information broadcast by the network. The configuration information is used to determine whether to allow access corresponding to the access identity. For example, the network may provide information for determining whether to allow access in the form of a bitmap (each bit of the bitmap is set to on or off) or probability information (such as a barring factor having a value ranging from 0 to 1) to indicate whether the corresponding access is allowed. If at least one of the non-zero access identities is allowed, the UE AS may not perform a barring check on the corresponding access based on the access category, and may eventually determine to allow access and perform an RRC connection setup. If the barring check for the corresponding access identity is not allowed, the UE NAS may bar the access and perform an additional barring check for the access category and barring configuration information corresponding to the access category to finally determine whether to perform the access.

If one access identity is received and the access identity is set to 0, the UE AS performs a barring check with the barring configuration information corresponding to the received access category. If it is determined that the barring check for the access category is allowed, the UE considers that access is allowed and it performs RRC connection establishment.

Fig. 7I is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure.

Referring to fig. 7i, the ue includes a Radio Frequency (RF) processor 7i-10, a baseband processor 7i-20, a storage unit 7i-30, and a controller 7i-40.

The RF processors 7i-10 have functions of transmitting/receiving signals through radio channels, such as band conversion and amplification of the signals. For example, the RF processors 7i-10 up-convert baseband signals from the baseband processors 7i-20 into RF band signals, and transmit the RF signals via an antenna, and down-convert RF signals received via the antenna into baseband signals. For example, the RF processors 7i-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC. Although one antenna is depicted in the drawing, the UE may be equipped with multiple antennas. The RF processors 7i-10 may also comprise a plurality of RF chains. The RF processors 7i-10 may perform beamforming. For beamforming, the RF processors 7i-10 may adjust the phase and magnitude of signals to be transmitted/received in phase and magnitude through an antenna or an antenna element. The RF processors 5i-10 may be configured to support a MIMO scheme by which the UE can receive multiple layers simultaneously.

The baseband processor 7i-20 has a baseband signal-to-bit string conversion function according to the system physical layer standard. For example, in the data transmission mode, the baseband processors 7i-20 perform coding and modulation on the transmission bit string to generate complex symbols. In the data reception mode, the baseband processor 7i-20 performs demodulation and decoding on the baseband signal from the RF processor 7i-10 to recover the transmitted bit string. In the case of using the OFDM scheme for data transmission, the baseband processors 7i-20 perform coding and modulation on a transmission bit string to generate complex symbols, map the complex symbols to subcarriers, perform IFFT on the symbols, and insert CPs into the symbols to generate OFDM symbols. In the data reception mode, the baseband processors 7i-20 divide the baseband signals from the RF processors 7i-10 into OFDM symbols, perform FFT on the OFDM symbols to recover the signals mapped to the subcarriers, and perform demodulation and decoding on the signals to recover the transmitted bit string.

The baseband processor 7i-20 and the RF processor 7i-10 process the transmission and reception signals as described above. The baseband processors 7i-20 and the RF processors 7i-10 may thus be referred to as transmitters, receivers, transceivers or communication units. At least one of the baseband processor 7i-20 and the RF processor 7i-10 may comprise a plurality of communication modules for supporting different radio access technologies. At least one of the baseband processor 7i-20 and the RF processor 7i-10 may further include a plurality of communication modules for processing signals in different frequency bands. For example, different radio access technologies may include Wireless Local Area Networks (WLANs) (e.g., institute of Electrical and Electronics Engineers (IEEE) 802.11) and cellular networks (e.g., LTE). The different frequency bands may include the ultra high frequency (SHF) band (e.g., 2.5GHz and 5GHz bands) and the mmWave band (e.g., 60 GHz).

The storage units 7i-30 store data such as basic programs for operating the UE, application programs, and setting information. The storage unit 7i-30 provides the stored information in response to a request from the controller 7i-40.

The controllers 7i-40 control the overall operation of the UE. For example, the controllers 7i-40 control the baseband processors 7i-20 and the RF processors 7i-10 to transmit and receive signals. The controllers 7i-40 write data to the memory cells 7i-30 and read data from the memory cells 7 i-30. To this end, the controllers 7i-40 may comprise at least one processor. For example, the controllers 7i-40 may include a CP for controlling communication and an AP for controlling higher layer programs (such as applications). The controllers 7i-40 may comprise multi-connection processors 7i-42 for processing operations in a multi-connection mode.

Referring to fig. 7j, the gnb includes RF processors 7j-10, baseband processors 7j-20, backhaul communication units 7j-30, memory units 7j-40, and controllers 7j-50.

The RF processors 7j-10 have functions of transmitting/receiving signals through radio channels, such as band conversion and amplification of the signals. For example, the RF processors 7j-10 up-convert the baseband signals from the baseband processors 7j-20 into RF band signals, and transmit the RF signals via the antennas, and down-convert the RF signals received via the antennas into baseband signals. For example, the RF processors 7j-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC. Although one antenna is depicted in the drawing, the gbb may be equipped with multiple antennas. The RF processors 7j-10 may also comprise a plurality of RF chains. The RF processors 7j-10 may perform beamforming. For beamforming, the RF processors 7j-10 may adjust the phase and magnitude of signals to be transmitted/received through the antennas or antenna elements. The RF processors 7j-10 may be configured to transmit one or more layers of downlink MIMO operation.

The baseband processors 7j-20 have a baseband signal-to-bit string conversion function according to the system physical layer standard. For example, in the data transmission mode, the baseband processors 7j to 20 perform coding and modulation on the transmission bit string to generate complex symbols. In the data reception mode, the baseband processor 7j-20 performs demodulation and decoding on the baseband signal from the RF processor 7j-10 to recover the transmitted bit string. In the case of using the OFDM scheme for data transmission, the baseband processors 7j-20 perform coding and modulation on a transmission bit string to generate complex symbols, map the complex symbols to subcarriers, perform IFFT on the symbols, and insert CPs into the symbols to generate OFDM symbols. In the data reception mode, the baseband processor 7j-20 divides the baseband signal from the RF processor 7j-10 into OFDM symbols, performs FFT on the OFDM symbols to recover the signal mapped to the subcarriers, and performs demodulation and decoding on the signal to recover the transmitted bit string. The baseband processors 7j-20 and the RF processors 7j-10 process the transmission and reception signals as described above. The baseband processor 7j-20 and the RF processor 7j-10 may thus be referred to as a transmitter, a receiver, a transceiver or a communication unit.

The backhaul communication units 7j-30 provide interfaces for communicating with other nodes in the network. For example, the backhaul communication units 7j-30 convert a bit string to be transmitted from the gNB to another node (e.g., another gNB and a core network) into a physical signal, and convert a physical signal received from another node into a bit string.

The storage units 7j-40 store data such as basic programs, application programs, and setting information for the gNB operation. The memory units 7j-40 may also store information about bearers established for the UE and measurement results reported by the connected UE. The memory units 7j-40 may also store information for the UE to use in determining whether to enable or disable multi-connectivity. The memory units 7j-40 may provide the stored data with reference to a request from the controller 7j-50.

Controllers 7j-50 control the overall operation of the gNB. For example, the controller 7j-50 controls the baseband processor 7j-20, the RF processor 7j-10, and the backhaul communication unit 7j-30 for transmitting and receiving signals. The controller 7j-50 reads and writes data to the memory cell 7 j-40. To this end, the controllers 7j-50 may comprise at least one processor. The controllers 7j-50 may also comprise multi-connection processors 7j-52 for processing operations in a multi-connection mode.

While the preferred embodiments of the disclosure have been described using specific terms, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense, in order to assist understanding of the disclosure. It will be evident to those skilled in the art that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. These embodiments may be combined in whole or in part, if desired. For example, some of the methods presented in this disclosure may be used in conjunction with the operation of the base station and the terminal. Although the embodiments are directed to LTE/LTE-a systems, it will be apparent that they may be applied to other systems (such as 5G systems or NR systems) to form other alternative embodiments without departing from the spirit and scope of the present disclosure.

While the disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.

Claims

1. A terminal in a communication system, the terminal comprising:

a transceiver; and

at least one processor configured to:

recognizing that access to the communication system is triggered,

identifying whether the access is classified into a predetermined access category of standardized access categories, the predetermined access category comprising an emergency access category,

applying a predetermined one of the standardized access categories to the access in case it is identified that the access is classified as a predetermined one of the standardized access categories, and

in case it is identified that the access is not classified into a predetermined one of the standardized access classes:

applying an operator classification based non-standardized access class to the access in case the access is classified into an access class of standardized access classes which are not predetermined access classes of standardized access classes, and the access is classified into an operator classification based non-standardized access class, and

in case the access is not classified as an operator classification based non-standardized access class, then applying an access class of a standardized access class, which is not a predetermined access class of standardized access classes, to the access

Wherein the non-standardized access classes based on operator classification are defined based on network slices.

2. The terminal of claim 1, wherein operator classification based non-standardized access categories are defined based on network slices and applications.

3. The terminal of claim 1, wherein the at least one processor is further configured to:

receiving via the transceiver from a base station barring information associated with the standardized access category, an

Determining whether to allow the access based on the barring information.

4. A terminal according to claim 3, wherein the barring information comprises a barring factor and a barring time, and

wherein the at least one processor is further configured to allow access if the random value is below a barring factor.

5. The terminal according to claim 1, wherein the terminal is capable of receiving the request,

wherein the access is classified into at least one standardized access category.

6. An access control method performed by a terminal in a communication system, the method comprising:

identifying that access to a communication system is triggered;

identifying whether the access is classified into a predetermined access category of standardized access categories, the predetermined access category comprising an emergency access category;

applying a predetermined one of the standardized access categories to the access if it is identified that the access is classified as the predetermined one of the standardized access categories; and

applying an operator classification based non-standardized access category to the access if the access is classified into an access category in a standardized access category that is not a predetermined access category in a standardized access category and the access is classified as the operator classification based non-standardized access category; and

in case the access is not classified as a non-standardized access category based on an operator classification, then an access category in a standardized access category, which is not a predetermined access category in the standardized access category, is applied to the access

7. The method of claim 6, wherein operator classification based non-standardized access categories are defined based on network slices and applications.

8. The method of claim 6, further comprising:

receiving barring information associated with the standardized access category from a base station; and

determining whether to allow the access based on the barring information.

9. The method of claim 8, wherein the barring information comprises a barring factor and a barring time, and

wherein access is allowed in case the random value is lower than the barring factor.

10. The method of claim 6, wherein the first and second light sources are selected from the group consisting of,