WO2019221436A1

WO2019221436A1 - Method and device for collecting and reporting cell measurement information in next generation mobile communication system

Info

Publication number: WO2019221436A1
Application number: PCT/KR2019/005426
Authority: WO
Inventors: 김상범; 정상엽; 김성훈
Original assignee: 삼성전자 주식회사
Priority date: 2018-05-16
Filing date: 2019-05-07
Publication date: 2019-11-21

Abstract

The present disclosure relates to a communication method and a system thereof which merge IoT technology with a 5G communication system for supporting a higher data transmission rate than 4G systems. The present disclosure can be applied to intelligent services (for example, smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail businesses, and security and safety-related services, etc.) on the basis of 5G communication technology and IoT-related technology. The present disclosure relates to a method and device for collecting and reporting cell measurement information in a next generation communication system, and relates to an integrity protection method and device for supporting vehicle communication.

Description

Method and apparatus for collecting and reporting cell measurement information in next generation mobile communication system

The present disclosure relates to a next generation mobile communication system, and relates to a method and apparatus for collecting and reporting cell measurement information by a terminal and a base station.

In addition, the present disclosure provides a sidelink radio bearer carrying V2X sidelink communication data (SLRB) terminal to support the V2X to support a variety of vehicle-to-everything (V2X) services in the next-generation mobile communication system And a method and apparatus for protecting integrity of a V2X packet in a PDCP layer.

In order to meet the increasing demand for wireless data traffic since the commercialization of 4G communication systems, efforts are being made to develop improved 5G communication systems or pre-5G communication systems. For this reason, a 5G communication system or a pre-5G communication system is called a Beyond 4G network communication system or a post LTE system.

In order to achieve high data rates, 5G communication systems are being considered for implementation in the ultra-high frequency (mmWave) band (eg, such as the 60 Gigabit (60 GHz) band). In 5G communication systems, beamforming, massive array multiple input / output (Full-Dimensional MIMO), and full dimensional multiple input / output (FD-MIMO) are used in 5G communication systems to increase path loss mitigation and propagation distance of radio waves in the ultra-high frequency band. Array antenna, analog beam-forming, and large scale antenna techniques are discussed.

In addition, in order to improve the network of the system, 5G communication systems have advanced small cells, advanced small cells, cloud radio access network (cloud RAN), ultra-dense network (ultra-dense network) , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation The development of such technology is being done.

In addition, in 5G systems, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC), Advanced Coding Modulation (ACM), and FBMC (Filter Bank Multi Carrier) and NOMA are advanced access technologies. (non orthogonal multiple access), and sparse code multiple access (SCMA), and the like are being developed.

Meanwhile, the Internet is evolving from a human-centered connection network in which humans create and consume information, and an Internet of Things (IoT) network that exchanges and processes information between distributed components such as things. The Internet of Everything (IoE) technology, which combines big data processing technology through connection with cloud servers and the like, is emerging. In order to implement the IoT, technical elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, a sensor network for connection between things, a machine to machine , M2M), Machine Type Communication (MTC), etc. are being studied. In an IoT environment, intelligent Internet technology (IT) services can be provided that collect and analyze data generated from connected objects to create new value in human life. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliances, advanced medical services, etc. through convergence and complex of existing information technology (IT) technology and various industries. It can be applied to.

Accordingly, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, machine to machine (M2M), machine type communication (MTC), and the like, are implemented by techniques such as beamforming, MIMO, and array antennas. It is. Application of cloud radio access network (cloud RAN) as the big data processing technology described above may be an example of convergence of 5G technology and IoT technology.

On the other hand, as described above, as the communication system develops, it is necessary to improve the process of collecting and reporting information on cell measurement results. In addition, there is a need for an efficient plan to support requirements and use cases for inter-vehicle communication services.

An object of the present disclosure is to enable efficient cell measurement by improving the collection and reporting process of cell measurement results in a next generation mobile communication system.

In addition, the present disclosure defines PPSe (ProSe Per Packet Integrity) to support integrity-protected V2X data in order to satisfy the requirements and use cases of the new V2X in the next-generation mobile communication system and accordingly By designing the behavior, we want to support various V2X services efficiently.

According to an embodiment of the present disclosure, a method of a terminal according to an embodiment of the present disclosure may include transmitting a first message for requesting a radio resource control (RRC) resume to a base station; Receiving a message, and transmitting a third message to complete the RRC resumption to the base station, the third message indicating that the terminal stores the measurement results performed in the RRC inactive state (RRC inactive state) Contains information.

The terminal according to another embodiment for solving the above problems, the transmission and reception unit configured to transmit and receive a signal, and transmits a first message requesting the radio resource control (RRC) resume (resume) to the base station, And a control unit configured to receive a second message indicating the resumption of RRC from the base station, and transmit a third message for completing the resumption of the RRC to the base station, wherein the third message is performed by the terminal in an RRC inactive state. Contains information indicating that the measurement results are being stored.

According to another aspect of the present invention, there is provided a method of a base station, the method comprising: receiving a first message requesting a radio resource control (RRC) resume from a terminal; And transmitting a third message, and receiving a third message for completing RRC resumption from the terminal, wherein the third message stores a measurement result performed by the terminal in an RRC inactive state. Includes informed information.

The base station according to another embodiment for solving the above problems, the transceiver unit configured to transmit and receive a signal, and receives a first message requesting the radio resource control (RRC) resume (resume) from the terminal, And a control unit configured to transmit a second message instructing the RRC resumption to the terminal and to receive a third message for completing the RRC resumption from the terminal, wherein the third message is performed by the terminal in an RRC inactive state. Contains information indicating that the measurement results are being stored.

According to another aspect of the present invention, there is provided a method of a terminal, comprising: receiving a V2X related parameter from a network entity, generating a V2X data packet, and wirelessly for a V2X data packet based on the V2X related parameter Determining a bearer, performing integrity protection for the V2X data packet, and transmitting the V2X data packet with integrity protection to the receiving device.

The terminal according to another embodiment to solve the problem, such as receiving and receiving the V2X-related parameters from the transceiver configured to transmit and receive a signal, and the network entity, generates a V2X data packet, based on the V2X-related parameters And a control unit configured to determine a radio bearer for the V2X data packet, to perform integrity protection for the V2X data packet, and to transmit the V2X data packet with the integrity protection to the receiving device.

According to an embodiment of the present disclosure, in the next generation mobile communication system, the collection and reporting procedure of cell measurement information may be improved, and thus efficient cell measurement may be performed.

According to another embodiment of the present disclosure, a PPPI may be defined to support various V2X services in a next generation mobile communication system. Accordingly, the terminal supporting the V2X based on PPPI selects the SLRB (Sidelink Radio Bearer carrying V2X sidelink communication data) and the PDCP PDU format determination method according to the V2X service and transmission method, thereby efficiently transmitting and receiving messages. Can be.

1A is a diagram illustrating the structure of a next generation mobile communication system.

FIG. 1B is a diagram for explaining a state of wireless access state transition in a next generation mobile communication system.

1C is a diagram illustrating a technique of collecting and reporting cell measurement information in the present embodiment.

1D is a diagram illustrating a method of collecting and reporting cell measurement information in this embodiment.

1E is a flowchart of an operation of collecting and reporting cell measurement information in this embodiment.

1F is a flowchart of an operation of collecting and reporting cell measurement information according to the embodiment 1-1.

1G is a flowchart of an operation of a base station for collecting and reporting cell measurement information in the embodiment 1-1.

1H is a flowchart illustrating an operation of a terminal for collecting and reporting cell measurement information according to an embodiment 1-2.

1I is a flowchart of an operation of a base station for collecting and reporting cell measurement information according to embodiments 1-2.

1J is a flowchart of an operation of collecting and reporting cell measurement information in embodiments 1-3;

1K is a block diagram showing the internal structure of a terminal to which the embodiment is applied.

1L is a block diagram showing the configuration of a base station according to the present embodiment.

2A is a diagram illustrating a structure of an LTE system to which an embodiment of the present invention can be applied.

2b is a diagram illustrating a radio protocol structure in an LTE system to which the present embodiment can be applied.

2C is a diagram illustrating the structure of a next generation mobile communication system to which the present embodiment can be applied.

2d is a diagram illustrating a radio protocol structure of a next generation mobile communication system to which the present embodiment can be applied.

2E is a diagram illustrating V2X communication in the next generation mobile communication system to which the present embodiment is applied.

FIG. 2F is a diagram illustrating a monitoring and data transmission procedure of a V2X terminal operating in mode 3 when a resource pool for each service and a resource pool irrespective of service type coexist in a next generation mobile communication system.

FIG. 2G illustrates a data transmission procedure of a V2X terminal operating in mode 4 when a resource pool for each service and a resource pool irrespective of service type coexist in a next generation mobile communication system.

2i is a block diagram of a terminal according to the present embodiment.

2J is a block diagram showing the configuration of a base station according to the present embodiment.

Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. At this time, it should be noted that the same components in the accompanying drawings are represented by the same reference numerals as possible. In addition, detailed descriptions of well-known functions and configurations that may blur the gist of the present disclosure will be omitted.

In describing the embodiments herein, descriptions of technical contents that are well known in the technical field to which the present disclosure belongs and are not directly related to the present disclosure will be omitted. This is to more clearly communicate without obscure the subject matter of the present disclosure by omitting unnecessary description.

For the same reason, in the accompanying drawings, some components are exaggerated, omitted or schematically illustrated. In addition, the size of each component does not fully reflect the actual size. The same or corresponding components in each drawing are given the same reference numerals.

Advantages and features of the present disclosure, and methods of accomplishing the same will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in various forms, and the present embodiments are merely provided to make the disclosure of the present disclosure complete and to provide general knowledge in the art to which the present disclosure belongs. It is provided to fully convey the scope of the disclosure to the person skilled in the art, and the present disclosure is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

At this point, it will be understood that each block of the flowchart illustrations and combinations of flowchart illustrations may be performed by computer program instructions. Since these computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, those instructions executed through the processor of the computer or other programmable data processing equipment may be described in flow chart block (s). It creates a means to perform the functions. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, and thus the computer usable or computer readable memory. It is also possible for the instructions stored in to produce an article of manufacture containing instruction means for performing the functions described in the flowchart block (s). Computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operating steps may be performed on the computer or other programmable data processing equipment to create a computer-implemented process to create a computer or other programmable data. Instructions for performing the processing equipment may also provide steps for performing the functions described in the flowchart block (s).

In addition, each block may represent a portion of a module, segment, or code that includes one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of order. For example, the two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the corresponding function.

In this case, the term '~ part' used in the present embodiment refers to software or a hardware component such as an FPGA or an ASIC, and '~ part' performs certain roles. However, '~' is not meant to be limited to software or hardware. May be configured to reside in an addressable storage medium or may be configured to play one or more processors. Thus, as an example, '~' means components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, and the like. Subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and the 'parts' may be combined into a smaller number of components and the 'parts' or further separated into additional components and the 'parts'. In addition, the components and '~' may be implemented to play one or more CPUs in the device or secure multimedia card.

First Embodiment

Referring to FIG. 1A, as shown, a radio access network of a next generation mobile communication system (New Radio, NR) includes a next generation base station (New Radio Node B, gNB) 1a-10 and an AMF 1a-05, New Radio. Core Network). The user terminal (New Radio User Equipment, NR UE or terminal) 1a-15 connects to the external network via gNB 1a-10 and AMF 1a-05.

In FIG. 1A, a gNB corresponds to an eNB (Evolved Node B) of an existing LTE system. The gNB is connected to the NR UE through a radio channel and can provide superior service than the existing Node B (1a-20). In the next generation mobile communication system, since all user traffic is serviced through a shared channel, an apparatus for scheduling by collecting state information such as buffer states, available transmit power states, and channel states of UEs is required. 1a-10). One gNB typically controls multiple cells. In order to implement ultra-high speed data transmission compared to the existing LTE, it may have more than the existing maximum bandwidth, and additionally beamforming technology may be combined by using orthogonal frequency division multiplexing (hereinafter, referred to as OFDM) as a wireless access technology. . In addition, an adaptive modulation & coding (AMC) scheme that determines a modulation scheme and a channel coding rate according to the channel state of the terminal is applied. The AMF 1a-05 performs functions such as mobility support, bearer setup, and QoS setup. The AMF is a device that is in charge of various control functions as well as mobility management function for the terminal and is connected to a plurality of base stations. In addition, the next-generation mobile communication system can be linked to the existing LTE system, the AMF is connected to the MME (1a-25) through a network interface. The MME is connected to the eNB 1a-30 which is an existing base station. The terminal supporting the LTE-NR Dual Connectivity may transmit and receive data while maintaining the connection to the eNB as well as the gNB (1a-35).

The next generation mobile communication system has three RRC states. The connected mode (RRC_CONNECTED, 1b-05) is a wireless connection state in which a terminal can transmit and receive data. The standby mode (RRC_IDLE, 1b-30) is a wireless access state in which the terminal monitors whether paging is transmitted to itself. The two modes are in a wireless access state applied to the existing LTE system, and the detailed technology is the same as that of the existing LTE system. In the next generation mobile communication system, a newly inactive (RRC_INACTIVE) radio access state (1b-15) is defined. In the radio access state, the UE context is maintained in the base station and the terminal, RAN-based paging is supported. The characteristics of the new wireless connection state are listed as follows.

Cell re-selection mobility;

CN-NR RAN connection (both C / U-planes) has been established for UE;

The UE AS context is stored in at least one gNB and the UE;

Paging is initiated by NR RAN;

RAN-based notification area is managed by NR RAN;

NR RAN knows the RAN-based notification area which the UE belongs to;

The new INACTIVE wireless connection state may transition to connected mode or standby mode using a specific procedure. The connection is switched from INACTIVE mode to connection mode according to the connection activation, and from the connection mode to the INACTIVE mode using the connection inactivation procedure (1b-10). The connection activation / inactivation procedure is one or more RRC messages transmitted and received between the terminal and the base station, characterized in that composed of one or more steps. It is also possible to switch from INACTIVE mode to standby mode according to a specific procedure (1b-20). As the specific procedure mentioned above, various methods such as specific message exchange or timer-based or event-based may be considered. The transition between connected and standby mode follows existing LTE technology. That is, switching between the modes is performed through a connection establishment or release procedure (1b-25).

1C is a diagram illustrating a technique of collecting and reporting cell measurement information in the present disclosure.

When constructing or optimizing a network, a mobile communication provider usually measures signal strength in an expected service area, and then arranges or readjusts base stations in the service area based on this. The operator loads signal measuring equipment in a vehicle and collects cell measurement information in the service area, which requires a lot of time and money. The process is commonly referred to as Drive Test, utilizing a vehicle. In order to support operations such as cell reselection, handover, and adding a serving cell when moving between cells, the terminal is equipped with a function of measuring a signal to a base station. Accordingly, the terminal in the service area may be used instead of the drive test, which is called a minimization of drive test (MDT). The operator may set MDT operation to specific terminals through various components of the network, and the terminals may receive signals from serving cells and neighbor cells in a connected mode (RRC_Connected), a standby mode (RRC_Idle), or an inactive mode (RRC_Inactive). Collect and store intensity information. In addition, various information such as location information, time information, and signal quality information is also stored. The stored information may be reported to the network when the terminals are in the connected mode, and the information is transmitted to a specific server.

The MDT operation is classified into Immediate MDT and Logged MDT.

Immediate MDT is characterized by directly reporting the collected information to the network. Since it should be reported immediately, only the connected mode terminal can perform this. Typically, the RRM measurement process is recycled to support operations such as handover and adding a serving cell, and location information and time information are additionally reported.

Logged MDT stores the collected information without immediately reporting it to the network. After that, the terminal switches to the connected mode and reports the stored information. Usually, the terminal in the standby mode that cannot report directly to the network performs this. In the present disclosure, the terminal in the inactive mode introduced in the next generation mobile communication system is characterized by performing Logged MDT. When the specific terminal is in the connected mode, the network provides the terminal with configuration information for performing a Logged MDT operation, and the terminal collects and stores the configured information after switching to the standby mode or the inactive mode.

In summary, it is shown in Table 1 below.

	RRC stateRRC state
Immediate MDTImmediate MDT	RRC_ConnectedRRC_Connected
Logged MDTLogged MDT	RRC_Idle, RRC_InactiveRRC_Idle, RRC_Inactive

1D is a diagram illustrating a method of collecting and reporting cell measurement information in this disclosure.

The terminal 1d-05 switches from the standby mode or the inactive mode 1d-10 to the connected mode 1d-15. In the connected mode, MDT data is collected and reported to the base station through Immediate MDT operation. The UE that has switched to the connected mode is provided with the Logged MDT configuration information performed in the standby mode or the inactive mode from the base station (1d-20). The configuration information is stored in a predetermined RRC message is transmitted to the terminal, the terminal receiving the message drives the first timer (1d-55). The terminal performs a Logged MDT operation in a standby mode or an inactive mode interval until the first timer expires. The value of the first timer is included in the Logged MDT configuration information. When the terminal switches to the standby mode or the inactive mode, Logged MDT is performed according to the received configuration information (1d-25). The terminal stores predetermined information collected every set period and logging interval (1d-35) (1d-30, 1d-45). In addition, if valid location information (1d-40) has been collected, the information must also be stored. Whether the location information is valid is determined to be valid after a predetermined time 1d-50 after collecting the information. The predetermined time is shorter or equal to the logged interval. Even before the first timer expires, the terminal temporarily suspends the Logged MDT operation that was being performed when switching to the connected mode (1d-60). However, the first timer does not stop even in the connected mode period and continues to be driven. That is, the first timer continues to run regardless of the change in the RRC state. However, when the terminal memory for storing the MDT data is insufficient and cannot be stored anymore, or when the Logged MDT configuration information is released, the first timer is stopped. When the Logged MDT configuration information is released, other Logged MDT configuration information is provided from a serving RAT or another RAT, or the terminal is detached or powered off. The UE reports to the base station that it has collected information (MDT data) that it stores using a predetermined RRC message during an RRC Connection Establishment or RRC Connection Resume (1d). -65). The connection restart process is a process in which the terminal switches from the inactive mode to the connected mode. As follows, it is generally composed of three steps, and three types of RRC messages are used.

Step 1: UE sends an RRC Resume Request message to the base station

Step 2: the base station transmits an RRC Resume message to the terminal

Step 3: UE sends an RRC Resume Complete message to the base station

Depending on the purpose of the resume may be composed of two steps. For example, the Resume process for RNA update,

Step 1: UE sends an RRC Resume Request message to the base station

Step 2: the base station transmits an RRC Resume message to the terminal

It can be configured as above. Detailed description will be described later. Information indicating that the terminal has the collection information is reported to the target base station during the RRC connection reestablishment and handover process, in addition to the connection establishment process or the connection restart process. If the Logged MDT is set but there is no information collected and stored yet, the report is omitted. The base station receiving the report may request a report of the MDT data stored in the terminal, if necessary. The unreported MDT data should be continuously stored by the terminal for a predetermined time. If the terminal is switched to the standby mode or inactive mode again, and the first timer has not yet expired, the Logged MDT operation is restarted again (1d-70). If the first timer expires, the Logged MDT operation stops (1d-75). The terminal that has stopped the operation drives the second timer (1d-80) and maintains the stored MDT data until the timer expires. After the timer expires, it is determined by the terminal implementation whether to delete the stored MDT data. The value of the second timer is included in the Logged MDT configuration information or is not set and a predefined value is applied. When the terminal is switched to the connected mode again, it reports to the base station that it has the collected information (MDT data) that it stores (1d-85). This time, the base station requests a report of the MDT data stored by the terminal using a predetermined RRC message (1d-90). Accordingly, the terminal stores MDT data stored in a predetermined RRC message and reports the message to the base station (1d-95).

1E is a flowchart of an operation of collecting and reporting cell measurement information in this disclosure.

The terminal 1e-05 establishes a connection with the base station 1e-10 (1e-15). The terminal provides the terminal capability information to the base station (1e-20) and may indicate whether it supports the MDT operation and what frequency can be measured. The base station stores the configuration information necessary to perform the Logged MDT operation in a predetermined RRC message and transmits it to the terminal (1e-25). In one example, the setting information includes at least one of the following information.

-Trace Reference Information

-Trace Recording Session Reference information

TCE (Trace Collection Entity) ID information: The base station transmits the MDT data information reported from the terminal to the data server designated by the TCE ID.

Absolute Time: Absolute time in the current cell providing Logged MDT configuration information.

Area Configuration: Through Logged MDT operation, area information that can collect and store measurement information is indicated by cell unit. It may also include RAT information for which measurement information should be collected. The list included in the RAT information is a black list or a white list. In the black list, cell measurement information is collected for RATs not included in the list. If it is a white list, cell measurement information is not collected for RATs not included in the list.

Logging Duration: A value of the first timer, when the timer is running, performs a Logged MDT operation in a standby mode or an inactive mode.

-Logging Interval: It is a cycle to save collected information.

plmn-IdentityList: PLMN list information, which stores PLMN information for reporting whether to store the MDT data and reporting MDT data as well as performing the logged MDT operation.

Indicator indicating whether to perform Logged MDT operation in standby mode or inactive mode, or both. The indicator may indicate an RRC state for performing a Logged MDT operation or may be defined to always perform a Logged MDT operation in a standby mode and an inactive mode without the indicator. The UE performs the Logged MDT operation only in the RRC state indicated by the indicator.

An indicator indicating whether to collect and store beam level measurement information. In the next generation mobile communication system, a beam antenna may be applied. Without the indicator, it can be defined to always collect and store beam level measurement measurements for frequencies that perform beam based operations.

Information on the maximum number of beams to be collected or stored, and information on the minimum signal strength of beams to be stored. The terminal omits the storage of beam information weaker than the minimum signal strength. If all beams are weaker than the set minimum signal value, the terminal may store one beam information having the strongest signal strength among them, or may include an indicator that all beams are weaker than the set minimum signal value.

Indicator indicating whether the MDT retrieval action can be triggered during a two-step restart process (RRC Resume)

The terminal receiving the Logged MDT configuration information drives the first timer (1e-30). The value of the first timer is set equal to the value of the logging duration. The base station switches the terminal to a standby mode or an inactive mode using an RRC Release message (1e-35). According to which RRC state to switch to, the RRC Release message contains configuration information for operation in the RRC state. If the first timer is running, the terminal performs Logged MDT in a standby mode or an inactive mode (1e-40). The signal strength of the serving cell and neighboring cells is measured, and location information is obtained. When the beam level measurement is set, the signal strength value for the beam larger than the set minimum value is collected and stored in the serving cell and the adjacent cell. The maximum number of beams that can be stored is also set or predefined. The signal strength means RSRP or RSRQ or SINR. The collected information is stored every Logged Interval period. Each log information stored in each cycle includes an indicator indicating whether the stored information is collected in a standby mode or in an inactive mode. Alternatively, the indicator may be included for each initial log of mode switching. This can minimize signaling overhead due to the indicator. When the first timer expires (1e-45), the Logged MDT operation is stopped (1e-50).

If the UE is in an inactive mode by the RRC Release message, and receives RAN or CN paging from the base station or if MO data transmission is activated, the UE performs a resume process for switching from the inactive mode to the connected mode. Initialize According to the present disclosure, the terminal may store a first indicator indicating whether there is MDT data stored in the RRC Resume Request or RRC Resume Complete message. For example, when the Resume process is triggered for the purpose of RNA update and is in the second step, the first indicator is stored in an RRC Resume Request message. Otherwise, if the resume process is to change the connection mode for data transmission, the process consists of three steps, and the first indicator is stored in the RRC Resume Complete message. In response to the RRC Resume Request message, the base station transmits an RRC Resume message to the terminal. If the RRC Resume Request message accommodates the first indicator (1e-55), and the base station wants to receive a report on the MDT data, the base station transmits the MDT data to the RRC Resume message (1e-60). It includes an indicator requesting a report for, or if the second stage Resume, the terminal includes an indicator to switch to the connected mode. Also, setting information necessary for switching to the connected mode is stored in the RRC Resume message. The terminal, having received the indicator, switches to the three-stage Resume process even if the RRC Resume Request message is triggered by the two-stage Resume process. If it is a three-step resume process, the first indicator is stored in the RRC Resume Complete message (1e-65). After receiving the RRC Resume Complete message, the base station requests a report of MDT data to the terminal using a predetermined RRC message (1e-70). Accordingly, the terminal reports the stored MDT data to the base station using a predetermined RRC message (1e-75).

If the terminal is in the standby mode by the RRC Release message and receives CN paging from the base station or if the MO data transmission is activated, the terminal initiates the establishment process for switching from the standby mode to the connected mode. . The establishment process,

Step 1: UE sends an RRC Connection Request message to the base station

Step 2: the base station transmits an RRC setup message to the terminal

Step 3: UE sends an RRC Setup Complete message to the base station

It is configured as above. The terminal includes an indicator indicating that there is MDT data stored in the RRC Setup Complete message. Upon receipt of the RRC Setup Complete message, the base station requests a report of the MDT data using a predetermined RRC message when necessary. The terminal receiving the request reports the MDT data using a predetermined RRC message.

In the first embodiment of the present disclosure, the first indicator may be included in a two or three step resume process. If the first indicator is stored in the Resume Request message in the two-stage resume process, it is switched to the three-stage resume process for MDT retrieval according to the determination of the base station. In the first and second embodiments, the first indicator is included only in the three-step resume process. That is, in the first and second embodiments, the first indicator may be included only in the RRC Resume Complete message without including the first indicator in the RRC Resume Request message during the two-step resume process. Therefore, for the RNA update, if the two-step Resume process is triggered, the terminal cannot perform the MDT retrieval. In the first to third embodiments, a method of subsequently reporting a failure of the resume process is proposed.

In step 1f-01, the terminal receives Logged MDT configuration information from the base station. The configuration information includes information necessary for performing a logged MDT operation in a standby mode or an inactive mode.

In step 1f-03, the UE receives an RRC Release message from the base station and switches to an inactive mode.

In step 1f-05, the terminal collects and stores cell measurement information and other additional information according to the Logged MDT configuration information.

In step 1f-10, the UE triggers a step 2 or step 3 resume process. The two stage Resume process is triggered mainly during RNA updates. In this case, the terminal normally receives a Resume message from the base station, and then switches back to inactive mode. The three-step resume process is triggered when the device switches to connected mode, primarily for data transfer.

In step 1f-15, if the step 2 is a resume process, the UE stores an indicator indicating that it has MDT data in the RRC Resume Request message. Then, the message is transmitted to the base station.

In step 1f-20, the UE receives an RRC Resume message including an indicator requesting report of MDT data or an indicator to switch to a connected mode from the base station. In the present disclosure, even if the two-step Resume process is triggered for the RNA update, when the base station requests, it is characterized in that the conversion to the three-step Resume process. If the indicator is not included in the message, the two-step resume process ends.

In step 1f-23, the terminal receives a predetermined RRC message requesting the report of MDT data from the base station.

In step 1f-25, the terminal reports a predetermined RRC message including MDT data to the base station.

In step 1f-30, if the step 3 is a resume process, the UE stores an indicator indicating that it has MDT data in the RRC Resume Complete message. Then, the message is transmitted to the base station.

In step 1f-35, if the terminal receives a predetermined RRC message requesting the report of the MDT data from the base station, in response, the terminal reports the predetermined RRC message including the MDT data to the base station.

Alternatively, if the terminal receives an RRC Resume message including an indicator requesting the report of the MDT data from the base station in step 1f-20, the terminal stores the MDT data stored in the RRC Resume Complete message, Report to the base station.

In step 1g-05, the base station determines which RRC message including the first indicator received from the specific terminal.

In step 1g-10, if the RRC message including the first indicator is an RRC Resume Request message, the base station determines whether to request MDT data from the terminal.

In step 1g-15, the base station stores an indicator for requesting the MDT report or an indicator for switching to the connected mode in the RRC Resume message, and then transmits the message to the terminal.

In step 1g-20, the base station receives an RRC Resume Request message from the terminal.

In step 1g-25, the base station transmits a predetermined RRC message requesting the report of MDT data to the terminal.

In step 1g-30, the base station receives a predetermined RRC message including MDT data from the terminal.

In step 1g-35, if the RRC message including the first indicator is an RRC Resume Request message, the base station determines whether to request MDT data from the terminal.

In step 1g-40, the base station transmits a predetermined RRC message requesting the report of MDT data to the terminal.

In step 1g-45, the base station receives a predetermined RRC message including MDT data from the terminal.

In step 1h-01, the terminal receives Logged MDT configuration information from the base station. The configuration information includes information necessary for performing a logged MDT operation in a standby mode or an inactive mode.

In step 1h-03, the terminal receives the RRC Release message from the base station, and switches to the inactive mode.

In step 1h-05, the terminal collects and stores cell measurement information and other additional information according to the Logged MDT configuration information.

In step 1h-10, the UE triggers a step 2 or step 3 resume process.

If the 2-step Resume process is triggered in step 1h-15, the UE generates an RRC Resume Request message without the first indicator, and transmits it to the serving base station. That is, MDT retrieval is excluded in the two-step resume process.

If the step 3 Resume process is triggered in steps 1h-20, the UE stores an indicator indicating that it has MDT data in the RRC Resume Complete message. Then, the message is transmitted to the base station.

If the terminal receives a predetermined RRC message requesting the report of the MDT data from the base station in steps 1h-25, in response, the terminal reports the predetermined RRC message including the MDT data to the base station.

In step 1i-05, the base station receives an RRC Resume Complete message including a first indicator from a specific terminal.

In step 1i-10, the base station determines whether to request MDT data from the terminal.

In step 1i-15, the base station transmits a predetermined RRC message requesting reporting of MDT data to the terminal.

In step 1i-20, the base station receives a predetermined RRC message including MDT data from the terminal.

The terminal reports the capability information of whether the terminal supports resume failure logging and reporting to the base station using a predetermined RRC message.

The base station instructs the connected mode terminal to resume failure logging by using a predetermined RRC message. The configuration information may be included in an RRCRelease message containing a suspend configuration. Or it may be included in a predetermined RRC message such as RRConfiguration. If the Resume failure logging is configured, the terminal stores information useful for coverage optimization, such as cell measurement information at that time, when the resume process is not successfully completed.

As another option, the terminal supporting the operation may always perform the operation when the resume process fails.

The terminal 1j-05 in the inactive mode may switch to the connected mode or trigger a resume process to perform an RNA update. The terminal starts the Resume process while transmitting an RRC Resume Request message to the base station 1j-10. While transmitting the RRC Resume Request message (1j-15), the terminal drives the second timer (1j-20). The second timer stops when receiving an RRC Resume message from the base station or when cell reselection is performed. If the RRC Resume message is not received from the BS until the second timer expires (1j-25), the UE considers that the triggered Resume process has failed. At this time, the terminal stores the collected cell measurement information and other additional information (1j-30). At least one of the information listed below is included.

An indicator indicating whether the expired second timer has begun to be driven by the establishment process or has started to run during the resume process;

A cause value value of the resume process in which the resume failure is detected. For example, RNA update, MO-signalling, MO-data, mt-Access, emergency, highPriorityAccess, delayTolerantAcess, mo-VoiceCall, etc.

CGI information (global cell ID) or PCI information (Physical cell ID) of the cell where the failure failure is detected

Signal strength, RSRP, RSRQ and SINR information of the cell where the failure is detected and its neighbors;

If the cells support beam operation, beam level signal strength, RSRP and RSRQ and SINR information of the cell where the failure has been detected and its neighbors;

-Location information of a valid terminal;

-Valid terminal speed information

-Information on the number of preambles transmitted by the MAC layer in a random access triggered for the resume process

An indicator indicating whether an unsuccessful contention resolution has occurred for a preamble transmitted at least once in a random access triggered for the resume process

An indicator indicating whether the terminal transmit power used in the last transmission preamble reaches the maximum terminal power in the random access triggered for the resume process

An indicator indicating whether the random access triggered for the resume process is performed in a normal uplink (NUL) or an additional uplink (SUL) (the indicator is also included in the establishment failure report)

After a predetermined time has elapsed, the terminal retries the resume process for switching from the inactive mode to the connected mode. The UE stores a third indicator indicating whether there is Establishment / Resume failure information stored in the RRC Resume Request or RRC Resume Complete message. The third indicator is indicated separately from the first indicator. In order to indicate whether there is establishment failure and resume failure information, a separate indicator may be defined. When the resume process is triggered for the purpose of RNA update and is in the second step, the third indicator is stored in an RRC Resume Request message. Otherwise, if the resume process is to switch the connection mode for data transmission, the process consists of three steps, and the third indicator is stored in the RRC Resume Complete message. In response to the RRC Resume Request message, the base station transmits an RRC Resume message to the terminal. If the RRC Resume Request message accommodates the third indicator (1j-35), and the base station wants to be reported about the establishment failure and Resume failure information, the base station in the RRC Resume message (1j-40) Include the indicator requesting the report on the establishment failure and Resume failure information, or if the second stage Resume, includes an indicator to switch to the connected mode. Also, setting information necessary for switching to the connected mode is stored in the RRC Resume message. The terminal, having received the indicator, switches to the three-stage Resume process even if the RRC Resume Request message is triggered by the two-stage Resume process. If the three-step resume process, the third indicator is stored in the RRC Resume Complete message (1j-45). After receiving the RRC Resume Complete message, the base station requests the terminal to report establishment failure and resume failure information using a predetermined RRC message (1j-50). Accordingly, the terminal reports the establishment failure and resume failure information to the base station using a predetermined RRC message (1j-55).

Alternatively, as in the first and second embodiments, retrieval for establishment failure and resume failure information may not be allowed in the two-step resume process.

Retrieval of establishment failure and resume failure information is also possible during the establishment process. The terminal includes an indicator indicating that there is Establishment failure and Resume failure information stored in the RRC Setup Complete message. Upon receipt of the RRC Setup Complete message, the base station requests a report of the establishment failure and resume failure information using a predetermined RRC message when necessary. The terminal receiving the request reports the establishment failure and resume failure information by using a predetermined RRC message.

The connected mode terminal reports capability information indicating whether to support the RRC resume failure reporting described in the first embodiment to the base station.

The RRC Inactive state is optional. Therefore, the terminal supporting the RRC Inactive state should always report the capability information. Or, the terminal supporting the RRC Inactive state always supports the RRC resume failure reporting.

The base station sets the RRC resume failure reporting to the connected mode terminal based on the capability information.

The base station transmits an RRCRelease message including a suspend configuration to the terminal, and the terminal switches to an inactive mode (RRC_Inactive).

The terminal triggers a resume process for the purpose of switching to the standby connection mode. When the terminal RRC triggers the transmission of the RRCResumeRequest message to the physical layer, the RRC starts a predetermined timer.

The timer is stopped when the RRCResume, RRCSetup, RRCRelease, or RRCReject message is received from the base station, a cell reselection operation is triggered, or the connection establishment is abandoned by a higher layer.

When the timer expires, the terminal considers resume failure and records valid measurement information collected at that time.

Thereafter, the terminal performs the resume process again, and if it fails again, deletes the previously recorded measurement information and records valid measurement information collected at the latest resume failure.

Thereafter, the terminal performs the resume process again. If the RRCResume or RRCSetup message is successfully received from the base station after transmitting the RRCResumeRequest message, the indicator indicating that the RRCResumeComplete or RRCSetupComplete message corresponding to the message records valid measurement information collected at the latest resume failure is stored. .

The terminal transmits the RRCResumeComplete or RRCSetupComplete message to the base station.

The terminal may simultaneously perform establishment failure reporting and resume failure reporting. At this time, the measurement information recorded at the establishment failure and the measurement information recorded at the resume failure are managed independently of each other.

This embodiment is characterized by integrating reporting at establishment failure or resume failure.

In order to save the memory usage of the terminal, only the measurement information recorded at the most recent establishment failure or resume failure may be maintained. For example, when a establishment failure occurs when a terminal having measurement information recorded at a previous resume failure occurs, the measurement information is deleted and the measurement information collected at a recent establishment failure is recorded. The availability indicator included in the RRCSetupComplete or the RRCResumeComplete indicates that there is measurement information recorded due to the failures without discriminating establishment failure or resume failure. The base station receiving the indicator may request the recorded measurement information. In response to the request, the terminal reports the recorded measurement information to the base station. The measurement information includes an indicator indicating whether the measurement information was collected at establishment failure or resume failure.

In the present embodiment, when the terminal performs the logged MDT, predetermined information is additionally collected according to an RRC state (standby mode or inactive mode).

The connected mode terminal receives configuration information required when performing logged MDT in the standby mode, the inactive mode, or both modes from the base station. The configuration information includes an indicator indicating whether to collect information that can be collected only in a specific RRC state. The terminal receiving the RRC message including the configuration information drives one timer by applying a timer duration (logging duration) included in the configuration information.

The connected mode terminal receives an RRCRelease message from the base station. If the suspend configuration information is included in the RRCRelease message, the terminal switches to inactive mode (RRC_Inactive), otherwise, switches to standby mode (RRC_Idle). The suspend configuration information includes at least I-RNTI, paging cycle, RAN Notification Area information, T380 timer information, and security information. The terminal that performs the logged MDT in the standby mode, the inactive mode, or the two modes stores the valid collection information at a set logging interval (logging time). The information stored at each logging point is stored in different entries and is distinguished from each other by including relative time information.

If the terminal is configured to perform logged MDT in the deactivation mode, additionally collects information that can be collected only in the deactivation mode. For example, the collection information is a list of RAN Notification Areas visited by the terminal and the number of times of RNA change. This information helps the operator determine the appropriate RNA. Another gathering information is an indicator of whether the RRC connection failed due to the expiration of the T319 timer. Normally logged MDT can be run in both inactive and standby mode. If the UE in the inactive mode performs a resume operation for switching the connected mode, but the resume process is considered to have failed due to the expiration of the T319 timer, the terminal is switched from the inactive mode to the standby mode. The resume process may be configured to store collected information of the logged MDT when the transition from the inactive mode to the standby mode fails. At the earliest logging time after the failure time of the resume process, an indicator indicating that the resume process has changed from an inactive mode to a standby mode due to a failure is stored. In addition, the number of preamble transmissions transmitted during the resume process, whether contention occurs, and indicator information on whether the maximum terminal transmission power has been reached may be added.

On the other hand, if the terminal is configured to perform logged MDT in the standby mode, additionally collects information that can be collected only in the standby mode. For example, the collection information is a list of the tracking areas visited by the terminal, the number of changes of the Tracking Area Update (TAU). This information assists the operator in determining the appropriate TAU.

The logged MDT operation is performed in standby mode or inactive mode or in both modes until the logging duration timer expires.

When the terminal is switched to the connected mode, the RRCSetupComplete or RRCResumeComplete includes an indicator indicating that the stored MDT information.

At this time, the base station may request the terminal to report the MDT information through a predetermined RRC message. In response to the request, the terminal reports the MDT information collected and stored using a predetermined RRC message.

The structure of the terminal is shown in Figure 1k.

Referring to the drawings, the terminal includes a radio frequency (RF) processor 1k-10, a baseband processor 1k-20, a storage unit 1k-30, and a controller 1k-40. .

The RF processor 1k-10 performs a function for transmitting and receiving a signal through a wireless channel such as band conversion and amplification of a signal. That is, the RF processor 1k-10 up-converts the baseband signal provided from the baseband processor 1k-20 into an RF band signal and transmits the same through an antenna, and receives the RF band signal received through the antenna. Downconverts to a baseband signal. For example, the RF processor 1k-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), and the like. Can be. In the figure, only one antenna is shown, but the terminal may include a plurality of antennas. In addition, the RF processor 1k-10 may include a plurality of RF chains. In addition, the RF processor 1k-10 may perform beamforming. For the beamforming, the RF processor 1k-10 may adjust phase and magnitude of each of signals transmitted and received through a plurality of antennas or antenna elements. In addition, the RF processor may perform MIMO, and may receive multiple layers when performing the MIMO operation.

The baseband processor 1k-20 performs a conversion function between the baseband signal and the bit string according to the physical layer standard of the system. For example, during data transmission, the baseband processor 1k-20 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processor 1k-20 restores the received bit string by demodulating and decoding the baseband signal provided from the RF processor 1k-10. For example, in accordance with an orthogonal frequency division multiplexing (OFDM) scheme, during data transmission, the baseband processor 1k-20 generates complex symbols by encoding and modulating a transmission bit stream, and the complex symbols are subcarriers. After mapping to, OFDM symbols are configured through inverse fast Fourier transform (IFFT) operation and cyclic prefix (CP) insertion. In addition, when receiving the data, the baseband processor 1k-20 divides the baseband signal provided from the RF processor 1k-10 into OFDM symbol units and subcarriers through fast Fourier transform (FFT) operations. After recovering the mapped signals, the received bit stream is recovered through demodulation and decoding.

The baseband processor 1k-20 and the RF processor 1k-10 transmit and receive signals as described above. Accordingly, the baseband processor 1k-20 and the RF processor 1k-10 may be referred to as a transmitter, a receiver, a transceiver, or a communicator. Furthermore, at least one of the baseband processor 1k-20 and the RF processor 1k-10 may include a plurality of communication modules to support a plurality of different radio access technologies. In addition, at least one of the baseband processor 1k-20 and the RF processor 1k-10 may include different communication modules to process signals of different frequency bands. For example, the different wireless access technologies may include a wireless LAN (eg, IEEE 802.11), a cellular network (eg, LTE), and the like. In addition, the different frequency bands may include a super high frequency (SHF) (eg 2.NRHz, NRhz) band and a millimeter wave (eg 60 GHz) band.

The storage unit 1k-30 stores data such as a basic program, an application program, and setting information for the operation of the terminal. In particular, the storage unit 1k-30 may store information related to a second access node that performs wireless communication using a second wireless access technology. The storage unit 1k-30 provides stored data at the request of the controller 1k-40.

The controller 1k-40 controls overall operations of the terminal. For example, the controller 1k-40 transmits and receives a signal through the baseband processor 1k-20 and the RF processor 1k-10. Also, the controller 1k-40 records and reads data in the storage unit 1k-40. To this end, the controller 1k-40 may include at least one processor. For example, the controller 1k-40 may include a communication processor (CP) for performing control for communication and an application processor (AP) for controlling a higher layer such as an application program.

1H is a block diagram of a base station in a wireless communication system according to a first embodiment of the present disclosure.

As shown in the figure, the base station includes an RF processor 1l-10, a baseband processor 1l-20, a backhaul communication unit 1l-30, a storage unit 1l-40, and a controller 1l-50. It is configured to include.

The RF processor 1l-10 performs a function for transmitting and receiving a signal through a wireless channel such as band conversion and amplification of the signal. That is, the RF processor 1l-10 up-converts the baseband signal provided from the baseband processor 1l-20 into an RF band signal and transmits the same through an antenna, and receives the RF band signal received through the antenna. Downconverts to a baseband signal. For example, the RF processor 1l-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like. In the figure, only one antenna is shown, but the first access node may have a plurality of antennas. In addition, the RF processor 1l-10 may include a plurality of RF chains. In addition, the RF processor 11-10 may perform beamforming. For the beamforming, the RF processor 1l-10 may adjust the phase and magnitude of each of the signals transmitted and received through a plurality of antennas or antenna elements. The RF processor may perform a downlink MIMO operation by transmitting one or more layers.

The baseband processor 1-20 performs a conversion function between the baseband signal and the bit string according to the physical layer standard of the first wireless access technology. For example, during data transmission, the baseband processor 1-20 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processor 1l-20 restores the received bit string by demodulating and decoding the baseband signal provided from the RF processor 1l-10. For example, according to the OFDM scheme, during data transmission, the baseband processor 1-20 generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then IFFT. OFDM symbols are constructed by operation and CP insertion. In addition, when receiving data, the baseband processor 1l-20 divides the baseband signal provided from the RF processor 1l-10 into OFDM symbol units and restores signals mapped to subcarriers through an FFT operation. After that, the received bit stream is recovered by demodulation and decoding. The baseband processor 1l-20 and the RF processor 1l-10 transmit and receive signals as described above. Accordingly, the baseband processor 1l-20 and the RF processor 1l-10 may be referred to as a transmitter, a receiver, a transceiver, a communication unit, or a wireless communication unit.

The backhaul communication unit 1l-30 provides an interface for communicating with other nodes in the network. That is, the backhaul communication unit 1l-30 converts a bit string transmitted from the main base station to another node, for example, an auxiliary base station, a core network, etc. into a physical signal, and converts the physical signal received from the other node Convert to heat

The storage unit 1-40 stores data such as a basic program, an application program, and setting information for the operation of the main station. In particular, the storage unit 1-40 may store information on a bearer allocated to the connected terminal, a measurement result reported from the connected terminal, and the like. In addition, the storage unit 1-40 may store information that is a criterion for determining whether to provide or terminate multiple connections to the terminal. The storage unit 1-40 provides the stored data at the request of the control unit 1l-50.

The controllers 1l-50 control the overall operations of the main station. For example, the controller 1l-50 transmits and receives a signal through the baseband processor 1l-20 and the RF processor 1l-10 or through the backhaul communication unit 1l-30. In addition, the control unit 1l-50 records and reads data in the storage unit 1l-40. To this end, the controller 1-50 may include at least one processor.

Second Embodiment

Terms used to identify connection nodes, terms referring to network objects, terms referring to messages, terms referring to interfaces between network objects, terms referring to various identification information, used in the following description. Etc. are illustrated for convenience of description. Thus, the present disclosure is not limited to the terms described below, and other terms may be used to refer to objects having equivalent technical meanings.

For convenience of description below, the present disclosure uses terms and names defined in the 3GPP LTE (3rd Generation Partnership Project Long Term Evolution) standard. However, the present disclosure is not limited to the above terms and names, and may be equally applied to systems conforming to other standards. In the present disclosure, the eNB may be used interchangeably with gNB for convenience of description. That is, the base station described as an eNB may represent a gNB.

2A is a diagram illustrating a structure of an LTE system to which the present disclosure may be applied.

Referring to FIG. 2A, a radio access network of an LTE system is shown in FIG. 2A with a next-generation base station (Evolved Node B, ENB, Node B or base station) 2a-05, 2a-10, 2a-15, and 2a-20. It consists of MME (2a-25, Mobility Management Entity) and S-GW (2a-30, Serving-Gateway). The user equipment (UE or UE) 2a-35 connects to the external network through the ENBs 2a-05 to 2a-20 and the S-GW 2a-30.

In FIG. 2A, the ENBs 2a-05 to 2a-20 correspond to existing Node Bs of the UMTS system. The ENB is connected to the UEs 2a-35 by radio channel and performs a more complicated role than the existing Node B. In LTE system, all user traffic, including real-time services such as Voice over IP (VoIP) over the Internet protocol, is serviced through a shared channel, so information on the status of buffers, available transmit power, and channel status of UEs is available. It is necessary to have a device that collects the scheduling, and ENB (2a-05 ~ 2a-20) is in charge. One ENB typically controls multiple cells. For example, in order to realize a transmission rate of 100 Mbps, the LTE system uses orthogonal frequency division multiplexing (hereinafter, referred to as OFDM) in a 20 MHz bandwidth as a radio access technology. In addition, an adaptive modulation & coding (AMC) scheme that determines a modulation scheme and a channel coding rate according to the channel state of the terminal is applied. The S-GW 2a-30 is a device for providing a data bearer, and generates or removes a data bearer under the control of the MME 2a-25. The MME is a device that is in charge of various control functions as well as mobility management function for the terminal and is connected to a plurality of base stations.

2B is a diagram illustrating a radio protocol architecture in an LTE system to which the present disclosure may be applied.

Referring to FIG. 2B, the wireless protocol of the LTE system is PDCP (Packet Data Convergence Protocol 2b-05, 2b-40), RLC (Radio Link Control 2b-10, 2b-35), MAC (Medium Access) at the UE and ENB, respectively. Control 2b-15, 2b-30). PDCP (Packet Data Convergence Protocol) (2b-05, 2b-40) is responsible for operations such as IP header compression / restoration. The main functions of PDCP are summarized as follows.

Header compression and decompression (ROHC only)

Transfer of user data

In-sequence delivery of upper layer PDUs at PDCP re-establishment procedure for RLC AM

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

Duplicate detection of lower layer SDUs at PDCP re-establishment procedure for RLC AM

Retransmission of PDCP SDUs at handover and, for split bearers in DC, of PDCP PDUs at PDCP data-recovery procedure, for RLC AM

Ciphering and deciphering

Timer-based SDU discard in uplink

Radio link control (hereinafter referred to as RLC) 2b-10 and 2b-35 may reconfigure PDCP PDUs (Packet Data Units) to appropriate sizes to perform ARQ operations. The main functions of RLC are summarized as follows.

Transfer of upper layer PDUs

Error Correction through ARQ (only for AM data transfer)

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

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

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

Duplicate detection (only for UM and AM data transfer)

Protocol error detection (only for AM data transfer)

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

RLC re-establishment

The MACs 2b-15 and 2b-30 are connected to several RLC layer devices configured in one terminal, and multiplex RLC PDUs to MAC PDUs and demultiplex RLC PDUs from MAC PDUs. The main functions of the MAC are summarized as follows.

Mapping between logical channels and transport channels

Multiplexing / demultiplexing of MAC SDUs belonging to one or different logical channels into / from transport blocks (TB) delivered to / from the physical layer on transport channels

Scheduling information reporting

HARQ function (Error correction through HARQ)

Priority handling between logical channels of one UE

Priority handling between UEs by means of dynamic scheduling

-MBMS service identification

Transport format selection

Padding function

The physical layer (2b-20, 2b-25) channel-coded and modulated the upper layer data, and made into OFDM symbols transmitted to the radio channel, or demodulated, channel decoded and transmitted to the upper layer by OFDM symbols received through the wireless channel Do the operation.

2C is a diagram illustrating a structure of a next generation mobile communication system to which the present disclosure may be applied.

Referring to FIG. 2C, the radio access network of the next generation mobile communication system (hereinafter referred to as NR or 5G) is shown as a next generation base station (New Radio Node B, NR gNB or NR base station) 2c-10 and NR CN (2c). -05, New Radio Core Network). The user terminal (New Radio User Equipment, NR UE or terminal) 2c-15 connects to the external network via NR gNB 2c-10 and NR CN 2c-05.

In FIG. 2C, the NR gNB 2c-10 corresponds to an eNB (Evolved Node B) of the existing LTE system. The NR gNB is connected to the NR UE 2c-15 in a wireless channel and may provide superior service than the existing Node B. In the next generation mobile communication system, since all user traffic is serviced through a shared channel, a device that collects and schedules state information such as buffer states, available transmit power states, and channel states of UEs is required. (2c-10) is in charge. One NR gNB typically controls multiple cells. In order to implement ultra-fast data transmission compared to the current LTE, it may have more than the existing maximum bandwidth, and additionally beamforming technology may be combined using an orthogonal frequency division multiplexing (OFDM) as a wireless access technology. . In addition, an adaptive modulation & coding (AMC) scheme that determines a modulation scheme and a channel coding rate according to the channel state of the terminal is applied. The NR CN 2c-05 performs mobility support, bearer setup, QoS setup, and the like. The NR CN is a device that is in charge of various control functions as well as mobility management function for a terminal and is connected to a plurality of base stations. In addition, the next generation mobile communication system can be interworked with the existing LTE system, and the NR CN is connected to the MME (2c-25) through a network interface. MME is connected to the eNB (2c-30) which is an existing base station.

2d is a diagram illustrating a radio protocol structure of a next generation mobile communication system to which the present disclosure can be applied.

Referring to FIG. 2D, the radio protocol of the next generation mobile communication system is NR PDCP (2d-05, 2d-40), NR RLC (2d-10, 2d-35), and NR MAC (2d-15) at the terminal and the NR base station, respectively. , 2d-30). The main functions of the NR PDCP (2d-05, 2d-40) may include some of the following functions.

Header compression and decompression (ROHC only)

Transfer of user data

In-sequence delivery of upper layer PDUs

Out-of-sequence delivery of upper layer PDUs

PDCP PDU reordering for reception

Duplicate detection of lower layer SDUs

Retransmission of PDCP SDUs

Ciphering and deciphering

Timer-based SDU discard in uplink

The order reordering function of the NR PDCP device refers to a function of reordering PDCP PDUs received from a lower layer based on a PDCP sequence number, and delivering data to an upper layer in a reordered order. It may include, or may include the ability to deliver immediately without considering the order, and may include the ability to rearrange the order to record the missing PDCP PDUs, status reporting for the missing PDCP PDUs May include a function for transmitting to the transmitting side, and may include a function for requesting retransmission for lost PDCP PDUs.

The main functions of the NR RLCs 2d-10 and 2d-35 may include some of the following functions.

Transfer of upper layer PDUs

In-sequence delivery of upper layer PDUs

Out-of-sequence delivery of upper layer PDUs

Error Correction through 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 function

RLC re-establishment

In-sequence delivery of the NR RLC device refers to a function of sequentially delivering the RLC SDUs received from the lower layer to the upper layer, and the original RLC SDU is divided into several RLC SDUs and received. If so, it may include a function of reassembling and delivering the same, and may include a function of rearranging the received RLC PDUs based on the RLC sequence number (PD) SN or PDCP sequence number (SN), May include a function of recording lost RLC PDUs, may include a function of reporting status of lost RLC PDUs to the sender, and may include a function of requesting retransmission of lost RLC PDUs. If there is a lost RLC SDU, it may include a function to deliver only the RLC SDUs up to the upper layer in order before the lost RLC SDU, or even if there is a missing RLC SDU If the timer has expired, it may include a function to deliver all the RLC SDUs received in order to the upper layer in order before the timer starts, or if the timer expires even if there is a missing RLC SDU, all the RLC SDUs received so far It may include a function to deliver them to the upper layer in order. In addition, the RLC PDUs may be processed in the order of receiving the RLC PDUs (regardless of the sequence number and sequence number), and delivered to the PDCP device in an out-of sequence delivery. Received segments stored in the buffer or to be received later may be reconfigured into an intact RLC PDU, and then processed and delivered to the PDCP device. The NR RLC layer may not include a concatenation function and may perform the function in the NR MAC layer or replace it with a multiplexing function of the NR MAC layer.

Out-of-sequence delivery of the NR RLC device refers to a function of directly delivering the RLC SDUs received from the lower layer to the upper layer regardless of the order, and the original one RLC SDU has several RLCs. When received divided into SDUs, it may include a function of reassembling and forwarding, and storing the lost RLC PDUs by storing and ordering the RLC SN or PDCP SN of the received RLC PDUs Can be.

The NR MACs 2d-15 and 2d-30 may be connected to several NR RLC layer devices configured in one terminal, and a main function of the NR MAC may include some of the following functions.

Mapping between logical channels and transport channels

Multiplexing / demultiplexing of MAC SDUs

Scheduling information reporting

HARQ function (Error correction through HARQ)

Priority handling between logical channels of one UE

Priority handling between UEs by means of dynamic scheduling

-MBMS service identification

Transport format selection

Padding function

The NR PHY layer (2d-20, 2d-25) channel-codes and modulates the higher layer data, transforms it into OFDM symbols and transmits it to the wireless channel, or demodulates and channel decodes the OFDM symbols received through the wireless channel to the higher layer. The transfer operation can be performed.

In the present disclosure, ProSe Per Packet Integrity (PPPI) is defined to support various V2X services in a next generation mobile communication system. In addition, the present invention proposes a method for selecting a SLRB (Sidelink Radio Bearer carrying V2X sidelink communication data) according to a V2X packet or a transmission method based on the PPPI-based UE. We also propose a method for determining the PDCP PDU format according to the PPPI value. Accordingly, the terminal can efficiently transmit and receive V2X messages.

Table 2 shows the types, ranges, and data rates for each V2X service in the next generation mobile communication system to which the present disclosure is applied.

Referring to Table 2, in the existing LTE system (Releases 14/15 V2X), low data rate, wide communication, such as Basic Safety Message (BSM), Cooperative Awareness Message (CAM), Decentralized Environmental Notification Message (DENM), and unidirectional P2X service, etc. In contrast to the support of uniform V2X services such as communication or transmission range and public service, next-generation mobile communication systems have introduced various services such as Advanced Driving, Extended Sensor, Platooning, etc. It is expected to support public, private or private services. Accordingly, the present disclosure proposes a method of classifying V2X services based on requirements and use cases for each service, as shown in Table 2 below. Refer to the 3GPP specification TR 22.886 “Study on enhancement of 3GPP Support for 5G V2X services” for the proposed table as follows.

	TypeType	RangeRange	Data RateData rate	UsageUsage
Rel-14/-15 V2XRel-14 / -15 V2X	PublicPublic	HighHigh	LowLow	BSM, CAM, DENM, P2XBSM, CAM, DENM, P2X
Advanced DrivingAdvanced driving	PublicPublic	MediumMedium	MediumMedium	Information sharing for automated driving,Intersection safety information,Cooperative lane change, etcInformation sharing for automated driving, Intersection safety information, Cooperative lane change, etc
Extended SensorExtended sensor	PublicPublic	Low (adjacent cars)Low (adjacent cars)	HighHigh
PlatooningPlaooning	Private/PublicPrivate / Public	Medium: Leader -> follower, follower -> leaderLow: follower <-> followerMedium: Leader-> follower, follower-> leaderLow: follower <-> follower	MediumMedium

2E is a diagram illustrating V2X communication in a next generation mobile communication system to which the present disclosure is applied.

V2X collectively refers to the communication technology through the vehicle and all interfaces, and depending on the form and the components that make up the communication, V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), and V2P (vehicle-to-pedestrian) And vehicle-to-network (V2N). V2P and V2V basically follow the structure and operation principle of Rel-13 device-to-device (D2D). For example, based on sidelink (PC5) operation, an actual data packet is transmitted / received through a sidelink, which is a transmission channel between terminals, not a base station and a terminal. This basic concept can be applied not only to the V2X defined in LTE, but also to the newly defined V2X in NR, and to the newly introduced scenario.

The base station 2e-01 includes at least one vehicle terminal 2e-05, 2e-10 and a pedestrian portable terminal 2e-15 located in the cell 2e-02 that supports V2X. For example, the vehicle terminal 2e-05 performs cellular communication using the link between the base station 2e-01 and the vehicle terminal-base station (Uu, 2e-30, 2e-35), and the other vehicle terminal 2e. -10) or communication with the pedestrian portable terminal (2e-15) by using side links (PC5, 2e-20, 2e-25). The base station may be an upgraded eNB supporting gNB or NR. The vehicle terminal 2e-05 and another vehicle 2e-10 or the vehicle terminals 2e-05 and 2e-10 and the pedestrian portable terminal 5c-15 may use the side links 2e-20 and 2e-25. In order to send and receive information directly, the base station should allocate a resource pool that can be used for sidelink communication. The following is a detailed description of how the base station allocates resources to UEs in V2X of the LTE system, and a similar approach to LTE can be applied to V2X introduced in the NR system. However, since NR uses various numerologies, the sidelink resource pool may be designed somewhat differently accordingly.

Depending on how the base station allocates resources to the terminal, it may be divided into two types: scheduled resource allocation (mode 3) and UE autonomous resource allocation (mode 4). In the case of the scheduled resource allocation, the base station allocates resources used for sidelink transmission to the RRC-connected terminals in a dedicated scheduling manner. The above method is effective for interference management and resource pool management (dynamic allocation, semi-persistence transmission) because the base station can manage the resources of the sidelink. In addition, in the case of a scheduled resource allocation (mode 3) in which the base station allocates and manages resources for V2X, when the terminal connected to the RRC has data to transmit to other terminals, the base station allocates an RRC message or MAC control element (Control). Element, hereinafter, CE). In this case, SidelinkUEInformation and UEAssistanceInformation messages may be used as the RRC message. Meanwhile, the MAC CE may be, for example, a buffer status report MAC CE in a new format (including at least an indicator indicating that the buffer status is reported for V2P communication and information on the size of data buffered for D2D communication). Refer to 3GPP Specification TS36.321 “E-UTRA MAC Protocol Specification” for the detailed format and contents of the buffer status report used by 3GPP. On the other hand, UE autonomous resource allocation allows a base station to provide a sidelink transmit / receive resource pool for V2X as system information, and the terminal selects a resource pool according to a predetermined rule. The resource selection method may include zone mapping, sensing-based resource selection, random selection, and the like, regardless of service or service type. The structure of the resource pool for V2X is adjacent to resources (2e-40, 2e-50, 2e-60) for scheduling allocation (SA) and resources (2e-45, 2e-55, 2e-65) for data transmission. One subchannel, and resources for SA (2e-70, 2e-75, 2e-80) and data (2e-85, 2e-90, 2e-95) may be used in a non-contiguous manner. It may be. Whichever of the above two structures is used, the SA consists of two consecutive PRBs and contains the content indicating the location of the resource for the data. The number of terminals receiving V2X service in one cell may be large, and the relationship between the base station 2e-01 and the terminals 2e-05, 2e-10, and 2e-15 described above may be extended. .

2F is a diagram illustrating a data transmission procedure of a V2X terminal operating in mode 3 in a next generation mobile communication system.

Referring to FIG. 2F, the V2X Application Server 2f-05 initially provides parameter provisioning so that the terminals 2f-01 and 2f-02 can perform V2X communication (2f-10). In addition, the V2X Control Function (2f-04) may receive the parameter information from the V2X Application Server (2f-05) and initially provide the parameter information so that the terminal (2f-01, 2f-02) can perform V2X communication ( 2f-10). The provisioned parameter includes mapping information of V2X services and Destination Layer-2 ID (s). For example, the next-generation mobile communication system needs to support new V2X services such as platooning, advanced driving, and extended sensors. Therefore, like the existing V2X service, the new V2X service is a PSID (Provider Service Identifier) or ITS-AIDs (Intelligent Transport System-) of the V2X application. Application Identifiers) or new Identifiers are used to map to Destination Layer-2 ID (s). The provisioned parameters may also include V2X frequencies and V2X services or V2X frequencies and V2X service types (e.g., PSID or ITS-AIDs or new Identifiers, etc.) or V2X frequencies and Radio Access Technology (RAT) as specified above. Contains mapping information. Here, V2X frequencies may represent the V2X LTE frequency or the V2X NR frequency, or both frequencies. Accordingly, the radio access technology may also represent E-UTRA or NR or both technologies. The mapping information specified above may additionally include information about a geographical area (s). For example, the V2X frequencies may not be available due to local regulations in certain geographic areas or the list of available V2X services or V2X service types may be different in a geographical area where privacy is sensitive. Information may also be included. In addition, the provisioned parameter includes mapping information of a V2X service and a communication range or a transmission range. In addition, the provisioned parameter includes mapping information on ProSe Per-Packet Priority (PPPP) and packet delay budget or V2X service and PPPP mapping information or V2X service and PPPR (ProSe Per-Packet Reliability) for V2X communication. ) Or mapping information of V2X services and ProSe Per-Packet Integrity (PPPI). The provisioned parameter also includes mapping information of a V2X service and a data transmission type. Here, the data transmission method means broadcast, multicast, groupcast, and unicast. The provisioned parameter also includes a transmission resource pool and a reception resource pool composed of PPPP or PPPR or a combination of PPPP and PPPR. The terminals 2f-01 and 2f-02 pre-configur the parameters initially provided from the V2X Application Server 2f-05 or the V2X Control Function 2f-04.

If the terminal 1 (2f-01) preset parameters are interested in a specific V2X service x, it performs a cell selection or cell selection procedure to find a suitable cell and find a cell to camp on (2f). -15). In this case, the terminal means finding a cell to camp on at a V2X frequency supported by a Home Public Land Mobile Network (HPLMN) mapped to a specific V2X service x. Camping-on terminal 1 (2f-01) receives the SIB21 from the base station (2f-03) (2f-20).

The system information 2f-20 includes a transmission resource pool and a reception resource pool composed of PPPP or PPPR or a combination of PPPP and PPPR. Specifically, the information may include information of a transmission resource pool and a reception resource pool of a serving cell and information of a reception resource pool of a neighbor cell of inter-frequency. In addition, the system information includes information for establishing synchronization with the resource pool information of the inter-RAT, zone setting information for the terminal to autonomously select resources and transmit data, sidelink (PC5) and LTE / NR uplink ( Uu) priority setting information, resource pool setting information (e.g., time domain resources in the bitmap format, frequency domain resources, subcarrier spacing information or cyclic prefix length if NR is supported), maximum allowable transmission power (maximum) transmission power configuration information including allowed transmission power) and configuration information for sensing operation are included.

When the terminal 1 (2f-01) read the system information is generated V2X packet (2f-25) for transmission, the terminal is PPPP applicable to the packet based on the V2X service provided by the packet, PPPR and PPPI values are determined. The terminal determines the transmission resource pool by a combination of PPPP and PPPR corresponding to the packet and then performs RRC connection with the base station (2f-30). In the RRC connection process, the UE may add information on a specific V2X service x (for example, PPPP, PPPR, or PPPI) to the base station or transmit information on the determined transmission resource pool as an RRC message. The transmission resource pool determination may be performed after the RRC connection. The RRC connection process may be performed before generating data traffic for a specific V2X service x (2f-30).

The terminal 1 2f-01 requests the base station 2f-03 to transmit resources capable of V2X communication with other terminals 2f-02 or the base station 2f-03 (2f-35). At this time, a transmission resource may be requested from a transmission resource pool determined by a combination of PPPP and PPPR corresponding to the V2X packet. The terminal 1 2f-01 may request the base station using an RRC message or a MAC CE (Control Element). In this case, SidelinkUEInformation and UEAssistanceInformation messages may be used as the RRC message. Meanwhile, the MAC CE may be, for example, a buffer status report MAC CE in a new format (including at least an indicator indicating that the buffer status report is for V2X communication and information on the size of data buffered for D2D communication). The base station 2f-03 allocates a V2X transmission resource to the terminal 1 2f-01 through a dedicated RRC message (2f-40). This message may be included in the RRCConnectionReconfiguration message. The resource allocation may be a V2X resource through Uu or a resource for PC5 depending on the type of transmission resource or traffic requested by the terminal, whether a corresponding link is congested, or a V2X service. For the determination, the UE adds PPPP or PPPR or PPPI or LCID information of V2X traffic through UEAssistance Information or MAC CE. Since the base station also knows information on resources used by other terminals, the base station schedules the resources requested by the terminal among the remaining resources. In addition, when the RRC message includes the SPS configuration information through Uu, the SPS may be activated by DCI transmission through the PDCCH (2f-45). Terminal 1 (5d-01) selects the transmission link and the transmission resource in accordance with the resources and transmission method allocated from the base station (5d-03) (2f-50).

The terminal 1 (2f-01) that has selected the transmission link and the transmission resource determines the sidelink radio bearer (SLRB) (2f-55). SLRB consists of a PDCP entity and an RLC entity. In the present disclosure, it is proposed that one SLRB is classified into a combination of an SRC / DST pair and a PPPP / PPPR / PPPI / LCID. For example, the SLRB may be classified as SRC / DST / PPPI or may also be classified as SRC / DST / PPPI / PPPR. UE 1 (2f-01) selects the SLRB when the V2X packet generated for transmission has an SLRB classified into SRC / DST / PPPI. If there is no SLRB divided into SRC / DST / PPPI, a new SLRB is created / created. The above-described SLRB selection or generation method can be applied by extending or contracting the relationship with any combination of SRC / DST / PPPI / PPPR / PPPP / LCID (2f-55).

The terminal 1 (2f-01) that selects / generates the SLRB processes the integrity protection of the V2X packet in the PDCP layer (2f-60). If PPPI is 1, the MAC-I is calculated and the PDCP Data PDU is formed by adding the MAC-I to the end of the V2X packet. In addition, after calculating the MAC-I according to the values of PPPP and PPPR, the PDCP Data PDU may be formed by adding MAC-I at the end of the V2X packet. In the present disclosure, it is proposed to introduce an indication value in which a calculated value of MAC-I exists by adding a 1 bit indicator to the PDCP header. For example, when the value of 1 bit indicator is 1, it may indicate that a calculated value of MAC-I exists. On the other hand, 0 may indicate that the calculated value of MAC-I does not exist. The terminal, which forms the PDCP Data PDU, transmits data to the terminals 2f-02 or the base station 2f-03 using the transmission resource pool selected based on the PPPP / PPPR (2f-65).

2g is a diagram illustrating a data transmission procedure of a V2X terminal operating in mode 4 in a next generation mobile communication system.

Referring to FIG. 2G, the V2X Application Server 2g-05 initially provides parameter information so that the terminals 2g-01 and 2g-02 can perform V2X communication (2g-10). In addition, the V2X Control Function (2g-04) may receive the parameter information from the V2X Application Server (2g-05) and initially provide the parameter information so that the terminal (2g-01, 2g-02) can perform V2X communication ( 2g-10). The provisioned parameter includes mapping information of V2X services and Destination Layer-2 ID (s). For example, the next-generation mobile communication system needs to support new V2X services such as platooning, advanced driving, and extended sensors. Therefore, like the existing V2X service, the new V2X service is a PSID (Provider Service Identifier) or ITS-AIDs (Intelligent Transport System-) of the V2X application. Application Identifiers) or new Identifiers are used to map to Destination Layer-2 ID (s). The provisioned parameters may also include V2X frequencies and V2X services or V2X frequencies and V2X service types (e.g., PSID or ITS-AIDs or new Identifiers, etc.) or V2X frequencies and Radio Access Technology (RAT) as specified above. Contains mapping information. Here, V2X frequencies may represent the V2X LTE frequency or the V2X NR frequency, or both frequencies. Accordingly, the radio access technology may also represent E-UTRA or NR or both technologies. The mapping information specified above may additionally include information about a geographical area (s). For example, the V2X frequencies may not be available due to local regulations in certain geographic areas or the list of available V2X services or V2X service types may be different in a geographical area where privacy is sensitive. Information may also be included. In addition, the provisioned parameter includes mapping information of a V2X service and a communication range or a transmission range. In addition, the provisioned parameters include mapping information on PPPP (Prose Per-Packet Priority) and packet delay budget or V2X service and PPPP mapping information or V2X service and PPPR (Prose Per-Packet Reliability) for V2X communication. ) Or mapping information of V2X services and ProSe Per-Packet Integrity (PPPI). The provisioned parameter also includes mapping information of a V2X service and a data transmission type. Here, the data transmission method means broadcast, multicast, groupcast, and unicast. It includes a transmission resource pool and a reception resource pool composed of PPPP or PPPR or a combination of PPPP and PPPR. The terminals 2g-01 and 2g-02 pre-configur the parameters initially provided from the V2X Application Server 2g-05 or the V2X Control Function 2f-04.

Unlike mode 3 in which the base station 2g-03 is directly involved in resource allocation, mode 4 operation autonomously selects a resource and transmits data based on a resource pool previously received by the terminal 1 (2g-01) through system information. There is a difference in that. In the present disclosure, in the V2X communication, the base station 2g-03 proposes to allocate a sidelink resource pool (V2V resource pool, V2P resource pool) for the terminal 1 (2g-01) based on a combination of PPPP and PPPR. The resource pool is composed of a resource pool that allows the terminal to autonomously select an available resource pool after sensing a resource used by other terminals, and a resource pool in which the terminal randomly selects a resource from a preset resource pool.

If the terminal 2g-01 preset parameters are interested in a specific V2X service x, the terminal 2g-01 performs a cell selection or a cell selection procedure to find a suitable cell and find a cell to camp on (2g-). 15). In this case, the terminal means finding a cell to camp on at a V2X frequency supported by a Home Public Land Mobile Network (HPLMN) mapped to a specific V2X service x. The camping-on terminal 2g-01 receives SIB21 from the base station 2g-03 (2g-20).

The system information 2f-20 includes a transmission resource pool and a reception resource pool composed of PPPP or PPPR or a combination of PPPP and PPPR. Specifically, the information may include information of a transmission resource pool and a reception resource pool of a serving cell and information of a reception resource pool of a neighbor cell of inter-frequency. In addition, the system information includes resource pool information for each service of the inter-RAT, information for setting synchronization, zone setting information for the terminal to autonomously select resources, and transmit data, and sidelink (PC5) and up / down LTE / NR Priority setting information of link (Uu), resource pool setting information (e.g., time domain resources, frequency domain resources in bitmap format, subcarrier spacing information or cyclic prefix length when NR is supported), and maximum allowable transmission power transmission power setting information including (maximum allowed transmission power) and setting information for sensing operation are included.

When data traffic for V2X is generated (2g-15) in the terminal 1 (2g-01), the terminal 1 (2g-01) is a transmission operation (set from the resource pool received through the system information from the base station 2g-03) Transmission resources in the time / frequency domain are selected (2g-30) according to dynamic allocation once transmission, dynamic allocation multiple transmission, sensing based one transmission, sensing based multiple transmission, random transmission) or PPPP / PPPR. Terminal 1 (2g-01) that selects a transmission resource determines the sidelink radio bearer (SLRB) (2g-35). SLRB consists of a PDCP entity and an RLC entity. In the present disclosure, it is proposed that one SLRB is classified into a combination of an SRC / DST pair and a PPPP / PPPR / PPPI / LCID. For example, the SLRB may be classified as SRC / DST / PPPI or may also be classified as SRC / DST / PPPI / PPPR. UE 1 (2g-01) selects the SLRB when the V2X packet generated for transmission has an SLRB classified into SRC / DST / PPPI. If there is no SLRB divided into SRC / DST / PPPI, a new SLRB is created / created. The above-described SLRB selection or generation method can be applied by extending or contracting the relationship with any combination of SRC / DST / PPPI / PPPR / PPPP / LCID (2g-35).

The terminal 1 (2g-01) that selects / generates the SLRB processes the integrity protection of the V2X packet in the PDCP layer (2g-40). If PPPI is 1, the MAC-I is calculated and the PDCP Data PDU is formed by adding the MAC-I to the end of the V2X packet. In addition, after calculating the MAC-I according to the values of PPPP and PPPR, the PDCP Data PDU may be formed by adding MAC-I at the end of the V2X packet. In the present disclosure, it is proposed to introduce an indication value in which a calculated value of MAC-I exists by adding a 1 bit indicator to the PDCP header. For example, when the value of 1 bit indicator is 1, it may indicate that a calculated value of MAC-I exists. On the other hand, 0 may indicate that the calculated value of MAC-I does not exist. The terminal that forms the PDCP Data PDU transmits data to the terminals 2g-02 or the base station 2g-03 using the transmission resource pool selected based on the PPPP / PPPR (2g-45).

FIG. 2H illustrates a PDCP PDU format applied to broadcast / multicast / groupcast / unicast in the NR V2X system proposed in the present disclosure. In the present disclosure, it is proposed to introduce a 1 bit indication in the PDCP header to indicate whether the MAC-I exists in the PDCP PDU format. For example, the R field 2h-05 may be used as a 1 bit indicator indicating whether MAC-I is present in the R field because the bit is reserved for an additional function which may be used later. In addition, in the present disclosure, the current SDU types (2h-10, 2h-15) are reserved for additional functions that can be used later from 100 to 111. One of these values indicates whether MAC-I exists. Suggest to indicate.

2i is a block diagram of a terminal according to the present disclosure.

As shown in FIG. 2i, the terminal according to the second embodiment of the present disclosure includes a transceiver 2i-05, a controller 2i-10, a multiplexing and demultiplexing unit 2i-15, and various higher layer processing units. 2i-20 and 2i-25, and a control message processing unit 2i-30.

The transceiver 2i-05 receives data and a predetermined control signal through a forward channel of a serving cell and transmits data and a predetermined control signal through a reverse channel. When a plurality of serving cells are set, the transceiver 2i-05 performs data transmission and reception and control signal transmission and reception through the plurality of serving cells. The multiplexing and demultiplexing unit 2i-15 multiplexes data generated by the upper layer processing units 2i-20 and 2i-25 or the control message processing unit 2i-30, or multiplexes the data received by the transceiver unit 2i-05. It demultiplexes and delivers to the appropriate upper layer processing units 2i-20 and 2i-25 or control message processing units 2i-30. The control message processing unit 2i-30 transmits and receives a control message from the base station and performs a necessary operation. It includes the ability to process RRC messages and control messages such as MAC CE, and includes reporting of CBR measurements and receiving RRC messages for resource pools and terminal operations. The upper layer processing units 2i-20 and 2i-25 mean DRB devices and may be configured for each service. Data generated from user services such as FTP (File Transfer Protocol) or Voice over Internet Protocol (VoIP) can be processed and transferred to the multiplexing and demultiplexing unit 2i-15, or from the multiplexing and demultiplexing unit 2i-15. Process the delivered data and deliver it to the higher level service application. The controller 2i-10 multiplexes the transceiver 2i-05 with the transceiver 2i-05 so as to check scheduling commands received through the transceiver 2i-05, for example, reverse grants, and perform reverse transmission on the appropriate transmission resource at an appropriate time. And the demultiplexer 2i-15. Meanwhile, in the above description, the terminal is composed of a plurality of blocks and each block performs a different function. However, this is only an example and is not necessarily limited thereto. For example, the controller 2i-10 may perform a function performed by the demultiplexer 2i-15.

2J is a block diagram of a base station according to the present disclosure.

The base station apparatus of FIG. 2J includes a transceiver 2j-05, a controller 2j-10, a multiplexing and demultiplexing unit 2j-20, a control message processing unit 2j-35, and various upper layer processing units 2j-25. , 2j-30), and a scheduler 2j-15.

The transceiver 2j-05 transmits data and a predetermined control signal through a forward carrier and receives data and a predetermined control signal through a reverse carrier. When a plurality of carriers are set, the transceiver 2j-05 performs data transmission and control signal transmission and reception to the plurality of carriers. The multiplexing and demultiplexing unit 2j-20 multiplexes data generated by the upper layer processing units 2j-25 and 2j-30 or the control message processing unit 2j-35, or multiplexes the data received by the transceiver unit 2j-05. It demultiplexes and delivers to the appropriate upper layer processing units 2j-25 and 2j-30, control message processing units 2j-35, and control unit 2j-10. The control message processing unit 2j-35 generates a message to be delivered to the terminal under the instruction of the control unit, and delivers the message to the lower layer. The upper layer processing units 2j-25 and 2j-30 may be configured for each terminal service, and may process data generated from user services such as FTP or VoIP, and transmit the data to the multiplexing and demultiplexing unit 2j-20. And process the data transmitted from the demultiplexer 2j-20 to the service application of the upper layer. The scheduler 2j-15 allocates transmission resources to the terminal at an appropriate time in consideration of the buffer state, channel state, and active time of the terminal, processes the signal transmitted by the terminal to the transceiver, or transmits the signal to the terminal. Do it.

The above-described second embodiment may be summarized as the following points.

Main point

1.Support Integrity Protection for V2X traffic

2.PPPI (Per Packet Integrity) to indicate whether certain packet shall be integrity protected.

3.1 bit indication in PDCP header to indicate MAC-I presence

4.PPPP / PPPR for Resource pool selection & PPPI for SLRB selection

Overall flow

1: UE <-V2X server: Parameter provisioning

The mapping of Destination Layer-2 ID (s) and the V2X services, e.g. PSID, ITS-AIDs, ES, platooning ...

-The mapping of services to V2X frequencies / RATs (LTE or NR or both)

The mapping of services to range (high, medium, low)

The mapping of services to PPPP, PPPR, PPPI (0 = no IP, 1 = IP)

The mapping of services to transmission type (broadcast, groupcast, unicast)

2: UE interested in V2X service x: Camping on a V2X frequency of HPLMN mapped to service x

3: UE: Receiving V2X system information

RX pools for serving cell and inter-frequency neighbor cell per PPPP / PPPR

TX pool for serving cell per PPPP / PPPR

4: V2X packet occurs for transmission

5: UE determines PPPP, PPPR and PPPI to be applicable for the V2X packet based on which service the packet is for

6: UE selects Tx Pool based on PPPP / PPPR of the packet

7: UE selects SLRB based on SRC / DST / PPPR / PPPI / PPPP

-SLRB is mapped with combination of SRC / DST / PPPI

-If no SLRB matches with SRC / DST / PPPI of the V2X packet, create new SLRB.

8: UE process V2X packet in the PDCP layer

-If PPPI is 1, calculate MAC-I, append it at the end of V2X packet. 1 bit indicator in PDCP header is set to 1 to indicate the presence of MAC-I

9: UE transmits V2X packet using the Tx Pool selected based on PPPP / PPPR

In specific embodiments of the present disclosure described above, the components included in the disclosure are expressed in the singular or plural number according to the specific embodiments presented. However, the singular or plural expressions are selected to suit the circumstances presented for convenience of description, and the present disclosure is not limited to the singular or plural elements, and the singular or plural elements may be used in the singular or the singular. Even expressed components may be composed of a plurality.

Meanwhile, in the detailed description of the present disclosure, specific embodiments have been described. However, various modifications may be possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

Claims

In a method of transmitting a signal from a terminal in a wireless communication system,

Transmitting a first message requesting resume of radio resource control (RRC) to the base station;

Receiving a second message from the base station instructing to resume RRC; And

Sending a third message to complete the RRC resumption to the base station,

The third message includes the information indicating that the UE stores the measurement result performed in the RRC inactive state.
The method of claim 1,

The method,

Receiving a fourth message requesting to report the measurement result from the base station; And

Sending a fifth message reporting the measurement result to the base station.
The method of claim 1,

The measurement results include data collected by performing a logged minimization of drive test (MDT).
The method of claim 1,

If the RRC resume procedure with the base station fails, the first message or the third message further comprises information indicating the failure of the RRC resume procedure.
In the terminal for transmitting a signal in a wireless communication system,

A transceiver configured to transmit and receive a signal; And

Sends a first message requesting a radio resource control (RRC) resume to the base station, receives a second message indicating the RRC resume from the base station, and transmits a third message to complete the RRC resume to the base station And a control unit configured to be

The third message is a terminal that includes information indicating that the terminal stores the measurement results performed in the RRC inactive state (RRC inactive state).
The method of claim 5,

The control unit,

Receiving a fourth message requesting to report the measurement result from the base station, and transmitting the fifth message reporting the measurement result to the base station.
The method of claim 5,

The measurement results include the data collected by performing a logged minimization of drive test (MDT).
The method of claim 5,

If the RRC resumption procedure with the base station fails, the first message or the third message further comprises information indicating the failure of the RRC resumption procedure.
A method for receiving a signal by a base station in a wireless communication system,

Receiving a first message for requesting to resume radio resource control (RRC) from the terminal;

Transmitting a second message instructing to resume RRC to the terminal; And

Receiving a third message to complete the RRC resume from the terminal,

The third message includes the information indicating that the UE stores the measurement result performed in the RRC inactive state.
The method of claim 9,

The method,

Transmitting a fourth message requesting to report the measurement result to the terminal; And

And receiving a fifth message reporting the measurement result from the terminal.
The method of claim 9,

The measurement results include data collected by performing a logged minimization of drive test (MDT),

If the RRC resume procedure with the base station fails, the first message or the third message further comprises information indicating the failure of the RRC resume procedure.
A base station for receiving a signal in a wireless communication system,

A transceiver configured to transmit and receive a signal; And

Receives a first message requesting a radio resource control (RRC) resume from the terminal, transmits a second message instructing the resumption of RRC to the terminal, and receives a third message to complete the RRC resume from the terminal And a control unit configured to be

The third message is a base station, which includes information indicating that the terminal stores the measurement result performed in the RRC inactive state (RRC inactive state).
The method of claim 12,

The control unit,

And a fourth message requesting to report the measurement result to the terminal, and further configured to receive a fifth message reporting the measurement result from the terminal.
The method of claim 12,

And the measurement result includes data collected by performing a logged minimization of drive test (MDT).
The method of claim 12,

If the RRC resume procedure with the base station fails, the first message or the third message further comprises information indicating the failure of the RRC resume procedure.