WO2024151120A1

WO2024151120A1 - Method and apparatus of scheduling request for delay aware buffer status mac ce transmission

Info

Publication number: WO2024151120A1
Application number: PCT/KR2024/000584
Authority: WO
Inventors: Sangkyu Baek; Anil Agiwal; Weiping Sun
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2023-01-13
Filing date: 2024-01-12
Publication date: 2024-07-18

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method performed by a user equipment (UE) in a communication system includes identifying that reporting of delay information associated with buffered data is triggered; identifying whether uplink shared channel (UL-SCH) resources are available for a new transmission, and the UL-SCH resources are available to accommodate (i) a medium access control (MAC) control element (CE) for the reporting of delay information and (ii) a subheader of the MAC CE for the reporting of delay information; generating the MAC CE for the reporting of delay information, in case that the UL-SCH resources are available for the new transmission, and the UL-SCH resources are available to accommodate the MAC CE for the reporting of delay information and the subheader of the MAC CE; and transmitting, to a base station, the MAC CE for the reporting of delay information.

Description

METHOD AND APPARATUS OF SCHEDULING REQUEST FOR DELAY AWARE BUFFER STATUS MAC CE TRANSMISSION

The disclosure relates generally to wireless communication systems and, more specifically, the disclosure relates to a method and an apparatus for scheduling request for delay aware buffer status medium access control (MAC) control element (CE) transmission.

5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in "Sub 6GHz" bands such as 3.5GHz, but also in "Above 6GHz" bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

Moreover, there has been ongoing standardization in air interface architecture/protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture/service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology for implementing system optimization by utilizing satellites and AI (Artificial Intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.

The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure.

The disclosure may provide to a method and an apparatus for scheduling request for delay aware buffer status MAC CE transmission.

The technical objects to be achieved by various embodiments of the disclosure are not limited to the technical objects mentioned above, and other technical objects not mentioned may be considered by those skilled in the art from various embodiments of the disclosure to be described below.

According to an embodiment of the disclosure, a method performed by a user equipment (UE) in a communication system is provided.

According to an embodiment of the disclosure, the method includes: identifying that reporting of delay information associated with buffered data is triggered; identifying whether uplink shared channel (UL-SCH) resources are available for a new transmission, and the UL-SCH resources are available to accommodate (i) a medium access control (MAC) control element (CE) for the reporting of delay information and (ii) a subheader of the MAC CE for the reporting of delay information; generating the MAC CE for the reporting of delay information, in case that the UL-SCH resources are available for the new transmission, and the UL-SCH resources are available to accommodate the MAC CE for the reporting of delay information and the subheader of the MAC CE; and transmitting, to a base station, the MAC CE for the reporting of delay information.

According to an embodiment of the disclosure, the method further includes in case that the UL-SCH resources are unavailable for the new transmission, or the UL-SCH resources are unavailable to accommodate the MAC CE for the reporting of delay information and the subheader of the MAC CE, triggering a scheduling request (SR).

According to an embodiment of the disclosure, the method further includes in case that (i) all data associated with the reporting of delay information is transmitted or (ii) a MAC protocol data unit (PDU) is transmitted and the MAC PDU includes a MAC CE including the delay information, cancelling the SR which is pending; and stopping sr-ProhibitTimer which is running.

According to an embodiment of the disclosure, whether the UL-SCH resources are available for the new transmission and the UL-SCH resources are available to accommodate the MAC CE for the reporting of delay information and the subheader for the MAC CE is identified, in case that the triggered reporting of delay information is not cancelled.

According to an embodiment of the disclosure, whether the UL-SCH resources are available to accommodate the MAC CE for the reporting of the delay information and the subheader for the MAC CE is identified as a result of logical channel prioritization.

According to an embodiment of the disclosure, the MAC CE for the reporting of delay information includes remaining time associated with the buffered data.

According to an embodiment of the disclosure, a user equipment (UE) in a communication system is provided.

According to an embodiment of the disclosure, the UE includes a transceiver and a processor coupled with the transceiver and configured to: identify that reporting of delay information associated with buffered data is triggered; identify whether uplink shared channel (UL-SCH) resources are available for a new transmission, and the UL-SCH resources are available to accommodate (i) a medium access control (MAC) control element (CE) for the reporting of delay information and (ii) a subheader of the MAC CE for the reporting of delay information; generate the MAC CE for the reporting of delay information, in case that the UL-SCH resources are available for the new transmission, and the UL-SCH resources are available to accommodate the MAC CE for the reporting of delay information and the subheader of the MAC CE; and transmit, to a base station, the MAC CE for the reporting of delay information.

According to an embodiment of the disclosure, the processor is further configured to in case that the UL-SCH resources are unavailable for the new transmission, or the UL-SCH resources are unavailable to accommodate the MAC CE for the reporting of delay information and the subheader of the MAC CE, trigger a scheduling request (SR).

According to an embodiment of the disclosure, the processor is further configured to in case that (i) all data associated with the reporting of delay information is transmitted or (ii) a MAC protocol data unit (PDU) is transmitted and the MAC PDU includes a MAC CE including the delay information, cancel the SR which is pending; and stop sr-ProhibitTimer which is running.

According to an embodiment of the disclosure, a method performed by a base station in a communication system is provided.

According to an embodiment of the disclosure, the method includes: transmitting, to a user equipment (UE), a radio resource control (RRC) message including configuration information associated with reporting of delay information associated with buffered data; and receiving, from the UE, a medium access control (MAC) control element (CE) for the reporting of delay information based on uplink shared channel (UL-SCH) resources, in case that the UL-SCH resources are available for a new transmission of the UE and the UL-SCH resources are available to accommodate the MAC CE for the reporting of delay information and (ii) a subheader of the MAC CE for the reporting of delay information.

According to an embodiment of the disclosure, the method further includes in case that the UL-SCH resources are unavailable for the new transmission, or the UL-SCH resources are unavailable to accommodate the MAC CE for the reporting of delay information and the subheader of the MAC CE, receiving a scheduling request (SR).

According to an embodiment of the disclosure, a base station in a communication system is provided.

According to an embodiment of the disclosure, the base station includes a transceiver and a processor coupled with the transceiver and configured to: transmit, to a user equipment (UE), a radio resource control (RRC) message including configuration information associated with reporting of delay information associated with buffered data; and receive, from the UE, a medium access control (MAC) control element (CE) for the reporting of delay information based on uplink shared channel (UL-SCH) resources, in case that the UL-SCH resources are available for a new transmission of the UE and the UL-SCH resources are available to accommodate the MAC CE for the reporting of delay information and (ii) a subheader of the MAC CE for the reporting of delay information.

The above-described various embodiments of the disclosure are merely some of the preferred embodiments of the disclosure, and various embodiments reflecting the technical features of the disclosure may be derived and understood by those skilled in the art based on the following detailed description of the disclosure.

The effects that can be achieved through the disclosure are not limited to the effects mentioned in the various embodiments, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

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

Figure 1 illustrates an example method performed by a UE according to an embodiment of the disclosure;

Figure 2 illustrates an example method performed by a UE according to an embodiment of the disclosure;

Figure 3 illustrates an electronic device according to embodiments of the disclosure; and

Figure 4 illustrates a base station according to embodiments of the disclosure.

Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms "include" and "comprise," as well as derivatives thereof, mean inclusion without limitation; the term "or," is inclusive, meaning and/or; the phrases "associated with" and "associated therewith," as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term "controller" means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely.

Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms "application" and "program" refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase "computer readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer readable medium" includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A "non-transitory" computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device.

Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

Figures 1 through 6, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system or device.

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

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

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

By the term "substantially" it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

It is known to those skilled in the art that blocks of a flowchart (or sequence diagram) and a combination of flowcharts may be represented and executed by computer program instructions. These computer program instructions may be loaded on a processor of a general purpose computer, special purpose computer, or programmable data processing equipment. When the loaded program instructions are executed by the processor, they create a means for carrying out functions described in the flowchart. Because the computer program instructions may be stored in a computer readable memory that is usable in a specialized computer or a programmable data processing equipment, it is also possible to create articles of manufacture that carry out functions described in the flowchart. Because the computer program instructions may be loaded on a computer or a programmable data processing equipment, when executed as processes, they may carry out operations of functions described in the flowchart.

A block of a flowchart may correspond to a module, a segment, or a code containing one or more executable instructions implementing one or more logical functions, or may correspond to a part thereof. In some cases, functions described by blocks may be executed in an order different from the listed order. For example, two blocks listed in sequence may be executed at the same time or executed in reverse order.

In this description, the words "unit", "module" or the like may refer to a software component or hardware component, such as, for example, a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC) capable of carrying out a function or an operation. However, a "unit", or the like, is not limited to hardware or software. A unit, or the like, may be configured so as to reside in an addressable storage medium or to drive one or more processors. Units, or the like, may refer to software components, object-oriented software components, class components, task components, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays or variables. A function provided by a component and unit may be a combination of smaller components and units, and may be combined with others to compose larger components and units. Components and units may be configured to drive a device or one or more processors in a secure multimedia card.

Prior to the detailed description, terms or definitions necessary to understand the disclosure are described. However, these terms should be construed in a non-limiting way.

The "base station (BS)" is an entity communicating with a user equipment (UE) and may be referred to as BS, base transceiver station (BTS), node B (NB), evolved NB (eNB), access point (AP), 5G NB (5gNB), or gNB.

The "UE" is an entity communicating with a BS and may be referred to as UE, device, mobile station (MS), mobile equipment (ME), or terminal.

To meet the demand for wireless data traffic having increased since deployment of fourth generation (4G) communication systems, efforts have been made to develop an improved fifth generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a 'Beyond 4G Network' or a 'Post long term evolution (LTE) System'. The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems. In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like. In the 5G system, Hybrid frequency shift keying (FSK) and Quadrature Amplitude Modulation (QAM) Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.

The Internet, which is a human centered connectivity network where humans generate and consume information, is now evolving to the Internet of Things (IoT) where distributed entities, such as things, exchange and process information without human intervention. The Internet of Everything (IoE), which is a combination of the IoT technology and the Big Data processing technology through connection with a cloud server, has emerged. As technology elements, such as "sensing technology", "wired/wireless communication and network infrastructure", "service interface technology", and "Security technology" have been demanded for IoT implementation, a sensor network, a Machine-to-Machine (M2M) communication, Machine Type Communication (MTC), and so forth have been recently researched. Such an IoT environment may provide intelligent Internet technology services that create a new value to human life by collecting and analysing data generated among connected things. IoT may be applied to a variety of fields including smart home, smart building, smart city, smart car or connected cars, smart grid, health care, smart appliances and advanced medical services through convergence and combination between existing Information Technology (IT) and various industrial applications.

In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as a sensor network, Machine Type Communication (MTC), and Machine-to-Machine (M2M) communication may be implemented by beamforming, MIMO, and array antennas. Application of a cloud Radio Access Network (RAN) as the above-described Big Data processing technology may also be considered to be as an example of convergence between the 5G technology and the IoT technology.

Carrier aggregation (CA)/Multi-connectivity in fifth generation wireless communication system is described. The fifth generation wireless communication system, supports standalone mode of operation as well dual connectivity (DC). In DC a multiple reception/transmission (Rx/Tx) user equipment (UE) may be configured to utilize resources provided by two different nodes (or node-Bs (NBs)) connected via non-ideal backhaul. One node acts as the Master Node (MN) and the other as the Secondary Node (SN). The MN and SN are connected via a network interface and at least the MN is connected to the core network. NR also supports Multi-RAT Dual Connectivity (MR-DC) operation whereby a UE in RRC_CONNECTED is configured to utilize radio resources provided by two distinct schedulers, located in two different nodes connected via a non-ideal backhaul and providing either Evolved Universal Terrestrial Radio Access (E-UTRA) (i.e. if the node is an next generation evolved Node-B (ng-eNB)) or NR access (i.e. if the node is a gNB).

In NR, for a UE in RRC_CONNECTED not configured with CA/DC, there is only one serving cell comprising of the primary cell. For a UE in RRC_CONNECTED configured with CA/ DC, the term 'serving cells' is used to denote the set of cells comprising of the Special Cell(s) and all secondary cells. In NR the term Master Cell Group (MCG) refers to a group of serving cells associated with the Master Node, comprising of the primary cell (PCell) and optionally one or more secondary cells (SCells). In NR the term Secondary Cell Group (SCG) refers to a group of serving cells associated with the Secondary Node, comprising of the primary secondary cell (or primary SCG cell) (PSCell) and optionally one or more SCells. In NR PCell (primary cell) refers to a serving cell in MCG, operating on the primary frequency, in which the UE either performs the initial connection establishment procedure or initiates the connection re-establishment procedure. In NR for a UE configured with CA, SCell is a cell providing additional radio resources on top of Special Cell. PSCell refers to a serving cell in SCG in which the UE performs random access when performing the Reconfiguration with Sync procedure. For Dual Connectivity operation the term Special Cell (SpCell) refers to the PCell of the MCG or the PSCell of the SCG, otherwise the term Special Cell refers to the PCell.

Random access in fifth generation wireless communication system is described. In the 5G wireless communication system, random access (RA) is supported. Random access (RA) is used to achieve uplink (UL) time synchronization. RA is used during initial access, handover, radio resource control (RRC) connection re-establishment procedure, scheduling request (SR) transmission, secondary cell group (SCG) addition/modification, beam failure recovery and data or control information transmission in UL by a non-synchronized UE in RRC CONNECTED state. Several types of random access procedure is supported such as contention based random access, contention free random access and each of these can be one of 2 step random access or 4 step random access.

Bandwidth part (BWP) operation in fifth generation wireless communication system is described. In fifth generation wireless communication system, bandwidth adaptation (BA) is supported. With BA, the receive and transmit bandwidth of a UE need not be as large as the bandwidth of the cell and can be adjusted: the width can be ordered to change (e.g. to shrink during period of low activity to save power); the location can be moved in the frequency domain (e.g. to increase scheduling flexibility); and the subcarrier spacing can be ordered to change (e.g. to allow different services). A subset of the total cell bandwidth of a cell is referred to as a Bandwidth Part (BWP). BA is achieved by configuring a RRC connected UE with BWP(s) and telling the UE which of the configured BWPs is currently the active one. When BA is configured, the UE only has to monitor physical downlink control channel (PDCCH) on the one active BWP i.e. it does not have to monitor PDCCH on the entire downlink (DL) frequency of the serving cell.

In RRC connected state, a UE is configured with one or more DL and UL BWPs, for each configured Serving Cell (i.e. PCell or SCell). For an activated Serving Cell, there is always one active UL and DL BWP at any point in time. The BWP switching for a Serving Cell is used to activate an inactive BWP and deactivate an active BWP at a time. The BWP switching is controlled by the PDCCH indicating a downlink assignment or an uplink grant, by the bwp-InactivityTimer, by RRC signaling, or by the MAC entity itself upon initiation of Random Access procedure. Upon addition of SpCell or activation of an SCell, at least one of the DL BWP indicated by firstActiveDownlinkBWP-Id and the UL BWP indicated by firstActiveUplinkBWP-Id is active without receiving PDCCH indicating a downlink assignment or an uplink grant. The active BWP for a Serving Cell is indicated by either RRC or PDCCH. For unpaired spectrum, a DL BWP is paired with a UL BWP, and BWP switching is common for both UL and DL. Upon expiry of BWP inactivity timer, the UE switch to the active DL BWP to the default DL BWP or initial DL BWP (if default DL BWP is not configured).

RRC states in fifth generation wireless communication system is described. In the fifth generation wireless communication system, RRC can be in one of the following states: RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED. A UE is either in RRC_CONNECTED state or in RRC_INACTIVE state when an RRC connection has been established. If this is not the case, i.e. no RRC connection is established, the UE is in RRC_IDLE state. The RRC states can further be characterized as follows:

In the RRC_IDLE, a UE specific discontinuous reception (DRX) may be configured by upper layers; The UE monitors Short Messages transmitted with paging radio network temporary identifier (RNTI) (P-RNTI) over downlink control information (DCI); monitors a Paging channel for core network (CN) paging using 5G-S-temoprary mobile subscriber identity (5G-S-TMSI); performs neighboring cell measurements and cell (re-)selection; acquires system information (SI) and can send SI request (if configured); performs logging of available measurements together with location and time for logged measurement configured UEs.

In RRC_INACTIVE, a UE specific DRX may be configured by upper layers or by RRC layer; UE stores a UE Inactive Access-Stratum (AS) context; a RAN-based notification area is configured by RRC layer. The UE monitors Short Messages transmitted with P-RNTI over DCI; monitors a Paging channel for CN paging using 5G-S-TMSI and RAN paging using full inactive-RNTI (I-RNTI); performs neighbouring cell measurements and cell (re-)selection; performs RAN-based notification area updates periodically and when moving outside the configured RAN-based notification area; acquires system information and can send SI request (if configured); performs logging of available measurements together with location and time for logged measurement configured UEs.

In the RRC_CONNECTED, the UE stores the AS context and transfer of unicast data to/from UE takes place; The UE monitors Short Messages transmitted with P-RNTI over DCI, if configured; monitors control channels associated with the shared data channel to determine if data is scheduled for it; provides channel quality and feedback information; performs neighbouring cell measurements and measurement reporting; acquires system information.

Physical downlink control channel (PDCCH) in fifth generation wireless communication system is described. In the fifth generation wireless communication system, PDCCH is used to schedule DL transmissions on physical downlink shared channel (PDSCH) and UL transmissions on physical uplink shared channel (PUSCH), where the Downlink Control Information (DCI) on PDCCH includes at least one of: Downlink assignments containing at least modulation and coding format, resource allocation, and hybrid-automatic repeat request (HARQ or hybrid-ARQ) information related to downlink shared channel (DL-SCH); Uplink scheduling grants containing at least modulation and coding format, resource allocation, and hybrid-ARQ information related to uplink shared channel (UL-SCH). In addition to scheduling, PDCCH can be used to for at least one of: Activation and deactivation of configured PUSCH transmission with configured grant; Activation and deactivation of PDSCH semi-persistent transmission; Notifying one or more UEs of the slot format; Notifying one or more UEs of the physical resource block(s) (PRB(s)) and orthogonal frequency division multiplexing (OFDM) symbol(s) where the UE may assume no transmission is intended for the UE; Transmission of transmit power control (TPC) commands for physical uplink control channel (PUCCH) and PUSCH; Transmission of one or more TPC commands for sounding reference signal (SRS) transmissions by one or more UEs; Switching a UE's active bandwidth part; Initiating a random access procedure.

A UE monitors a set of PDCCH candidates in the configured monitoring occasions in one or more configured COntrol REsource SETs (CORESETs) according to the corresponding search space configurations. A CORESET consists of a set of PRBs with a time duration of 1 to 3 OFDM symbols. The resource units Resource Element Groups (REGs) and Control Channel Elements (CCEs) are defined within a CORESET with each CCE consisting a set of REGs. Control channels are formed by aggregation of CCE. Different code rates for the control channels are realized by aggregating different number of CCE. Interleaved and non-interleaved CCE-to-REG mapping are supported in a CORESET. Polar coding is used for PDCCH. Each resource element group carrying PDCCH carries its own demodulation reference signal (DMRS). Quadrature Phase Shift Keying (QPSK) modulation is used for PDCCH.

In fifth generation wireless communication system, a list of search space configurations is signaled by gNB for each configured BWP of serving cell wherein each search space configuration is uniquely identified by a search space identifier. Search space identifier is unique amongst the BWPs of a serving cell. Identifier of search space configuration to be used for specific purpose such as paging reception, SI reception, random access response reception is explicitly signaled by gNB for each configured BWP. In NR search space configuration comprises of parameters Monitoring-periodicity-PDCCH-slot, Monitoring-offset-PDCCH-slot, Monitoring-symbols-PDCCH-within-slot and duration. A UE determines PDCCH monitoring occasion (s) within a slot using the parameters PDCCH monitoring periodicity (Monitoring-periodicity-PDCCH-slot), the PDCCH monitoring offset (Monitoring-offset-PDCCH-slot), and the PDCCH monitoring pattern (Monitoring-symbols-PDCCH-within-slot). PDCCH monitoring occasions are there in slots 'x' to x+duration where the slot with number 'x' in a radio frame with number 'y' satisfies the equation below:

(y*(number of slots in a radio frame) + x - Monitoring-offset-PDCCH-slot) mod (Monitoring-periodicity-PDCCH-slot) = 0;

The starting symbol of a PDCCH monitoring occasion in each slot having PDCCH monitoring occasion is given by Monitoring-symbols-PDCCH-within-slot. The length (in symbols) of a PDCCH monitoring occasion is given in the CORESET associated with the search space. Search space configuration includes the identifier of CORESET configuration associated with it. A list of CORESET configurations is signaled by gNB for each configured BWP of serving cell wherein each coreset configuration is uniquely identified by an coreset identifier. CORESET identifier is unique amongst the BWPs of a serving cell. Note that each radio frame is of 10ms duration. Radio frame is identified by a radio frame number or system frame number. Each radio frame comprises of several slots wherein the number of slots in a radio frame and duration of slots depends on sub carrier spacing (SCS). The number of slots in a radio frame and duration of slots depends on radio frame for each supported SCS is pre-defined in NR.

Each CORESET configuration is associated with a list of Transmission configuration indicator (TCI) states. One downlink reference signal (DL RS) identifier (ID) (synchronization signal block (SSB) or channel state information reference signal (CSI RS)) is configured per TCI state. The list of TCI states corresponding to a CORESET configuration is signaled by gNB via RRC signaling. One of the TCI state in TCI state list is activated and indicated to UE by gNB. TCI state indicates the DL TX beam (DL TX beam is quasi co-located (QCLed) with SSB/CSI RS of TCI state) used by gNB for transmission of PDCCH in the PDCCH monitoring occasions of a search space.

Downlink scheduling in fifth generation wireless communication system is described. In the downlink, the gNB can dynamically allocate resources to UEs via the cell-RNTI (C-RNTI) on PDCCH(s). A UE always monitors the PDCCH(s) in order to find possible assignments when its downlink reception is enabled (activity governed by DRX when configured). When CA is configured, the same C-RNTI applies to all serving cells.

The gNB may pre-empt an ongoing PDSCH transmission to one UE with a latency-critical transmission to another UE. The gNB can configure UEs to monitor interrupted transmission indications using interruption-RNTI (INT-RNTI) on a PDCCH. If a UE receives the interrupted transmission indication, the UE may assume that no useful information to that the UE was carried by the resource elements included in the indication, even if some of those resource elements were already scheduled to this UE.

In addition, with Semi-Persistent Scheduling (SPS), the gNB can allocate downlink resources for the initial HARQ transmissions to UEs: RRC defines the periodicity of the configured downlink assignments while PDCCH addressed to configured scheduling-RNTI (CS-RNTI) can either signal and activate the configured downlink assignment, or deactivate it; i.e. a PDCCH addressed to CS-RNTI indicates that the downlink assignment can be implicitly reused according to the periodicity defined by RRC, until deactivated. When required, retransmissions are explicitly scheduled on PDCCH(s).

The dynamically allocated downlink reception overrides the configured downlink assignment in the same serving cell, if they overlap in time. Otherwise, a downlink reception according to the configured downlink assignment is assumed, if activated. The UE may be configured with up to 8 active configured downlink assignments for a given BWP of a serving cell. When more than one is configured:

- The network decides which of these configured downlink assignments are active at a time (including all of them); and

- Each configured downlink assignment is activated separately using a DCI command and deactivation of configured downlink assignments is done using a DCI command, which can either deactivate a single configured downlink assignment or multiple configured downlink assignments jointly.

Uplink scheduling in fifth generation wireless communication system is described. In the uplink, the gNB can dynamically allocate resources to UEs via the C-RNTI on PDCCH(s). A UE always monitors the PDCCH(s) in order to find possible grants for uplink transmission when its downlink reception is enabled (activity governed by DRX when configured). When CA is configured, the same C-RNTI applies to all serving cells.

The gNB may cancel a PUSCH transmission, or a repetition of a PUSCH transmission, or an SRS transmission of a UE for another UE with a latency-critical transmission. The gNB can configure UEs to monitor cancelled transmission indications using cancellation indication-RNTI (CI-RNTI) on a PDCCH. If a UE receives the cancelled transmission indication, the UE shall cancel the PUSCH transmission from the earliest symbol overlapped with the resource or the SRS transmission overlapped with the resource indicated by cancellation. In addition, with Configured Grants, the gNB can allocate uplink resources for the initial HARQ transmissions and HARQ retransmissions to UEs. Two types of configured uplink grants are defined:

- With Type 1, RRC directly provides the configured uplink grant (including the periodicity).

- With Type 2, RRC defines the periodicity of the configured uplink grant while PDCCH addressed to CS-RNTI can either signal and activate the configured uplink grant, or deactivate it; i.e. a PDCCH addressed to CS-RNTI indicates that the uplink grant can be implicitly reused according to the periodicity defined by RRC, until deactivated.

If the UE is not configured with enhanced intra-UE overlapping resources prioritization, the dynamically allocated uplink transmission overrides the configured uplink grant in the same serving cell, if they overlap in time. Otherwise, an uplink transmission according to the configured uplink grant is assumed, if activated.

If the UE is configured with enhanced intra-UE overlapping resources prioritization, in case a configured uplink grant transmission overlaps in time with dynamically allocated uplink transmission or with another configured uplink grant transmission in the same serving cell, the UE prioritizes the transmission based on the comparison between the highest priority of the logical channels that have data to be transmitted and which are multiplexed or can be multiplexed in medium access control (MAC) protocol data units (PDUs) associated with the overlapping resources. Similarly, in case a configured uplink grant transmissions or a dynamically allocated uplink transmission overlaps in time with a scheduling request transmission, the UE prioritizes the transmission based on the comparison between the priority of the logical channel which triggered the scheduling request and the highest priority of the logical channels that have data to be transmitted and which are multiplexed or can be multiplexed in MAC PDU associated with the overlapping resource. In case the MAC PDU associated with a deprioritized transmission has already been generated, the UE keeps it stored to allow the gNB to schedule a retransmission. The UE may also be configured by the gNB to transmit the stored MAC PDU as a new transmission using a subsequent resource of the same configured uplink grant configuration when an explicit retransmission grant is not provided by the gNB.

Retransmissions other than repetitions are explicitly allocated via PDCCH(s) or via configuration of a retransmission timer.

The UE may be configured with up to 12 active configured uplink grants for a given BWP of a serving cell. When more than one is configured, the network decides which of these configured uplink grants are active at a time (including all of them). Each configured uplink grant can either be of Type 1 or Type 2. For Type 2, activation and deactivation of configured uplink grants are independent among the serving cells. When more than one Type 2 configured grant is configured, each configured grant is activated separately using a DCI command and deactivation of Type 2 configured grants is done using a DCI command, which can either deactivate a single configured grant configuration or multiple configured grant configurations jointly.

When supplementary uplink (SUL) is configured, the network should ensure that an active configured uplink grant on SUL does not overlap in time with another active configured uplink grant on the other UL configuration.

For both dynamic grant and configured grant, for a transport block, two or more repetitions can be in one slot, or across slot boundary in consecutive available slots with each repetition in one slot. For both dynamic grant and configured grant Type 2, the number of repetitions can be also dynamically indicated in the layer 1(L1) signaling. The dynamically indicated number of repetitions shall override the RRC configured number of repetitions, if both are present.

Discontinuous Reception (DRX) in fifth generation wireless communication system is described. In 5G wireless communication system, the PDCCH monitoring activity of the UE in RRC connected mode is governed by DRX, BA and DCI with cyclic redundancy check (CRC) scrambled by power saving-RNTI (PS-RNTI) (DCP). When DRX is configured, the UE does not have to continuously monitor PDCCH. DRX is characterized by the following:

- on-duration: duration that the UE waits for, after waking up, to receive PDCCHs. If the UE successfully decodes a PDCCH, the UE stays awake and starts the inactivity timer;

- inactivity-timer: duration that the UE waits to successfully decode a PDCCH, from the last successful decoding of a PDCCH, failing which it can go back to sleep. The UE shall restart the inactivity timer following a single successful decoding of a PDCCH for a first transmission only (i.e. not for retransmissions);

- retransmission-timer: duration until a retransmission can be expected;

- cycle: specifies the periodic repetition of the on-duration followed by a possible period of inactivity;

- active-time: total duration that the UE monitors PDCCH. This includes the "on-duration" of the DRX cycle, the time when the UE is performing continuous reception while the inactivity timer has not expired, and the time when the UE is performing continuous reception while waiting for a retransmission opportunity.

Logical channel prioritization (LCP) in fifth generation wireless communication system is described. In NR, the UE has an uplink rate control function which manages the sharing of uplink resources between logical channels. RRC controls the uplink rate control function by giving each logical channel a priority, a prioritized bit rate (PBR), and a buffer size duration (BSD). In addition, mapping restrictions can be configured. With LCP restrictions in MAC, RRC can restrict the mapping of a logical channel to a subset of the configured cells, numerologies, PUSCH transmission durations, configured grant configurations and control whether a logical channel can utilise the resources allocated by a Type 1 Configured Grant or whether a logical channel can utilise dynamic grants indicating a certain physical priority level. With such restrictions, it then becomes possible to reserve, for instance, the numerology with the largest subcarrier spacing and/or shortest PUSCH transmission duration for Ultra-Reliable and Low Latency Communications (URLLC) services. Furthermore, RRC can associate logical channels with different SR configurations, for instance, to provide more frequent SR opportunities to URLLC services. The uplink rate control function ensures that the UE serves the logical channel(s) in the following sequence:

1. All relevant logical channels in decreasing priority order up to their PBR;

2. All relevant logical channels in decreasing priority order for the remaining resources assigned by the grant.

In case the PBRs are all set to zero, the first step is skipped and the logical channels are served in strict priority order: the UE maximizes the transmission of higher priority data.

The mapping restrictions tell the UE which logical channels are relevant for the grant received. If no mapping restrictions are configured, all logical channels are considered.

If more than one logical channel has the same priority, the UE shall serve them equally.

Buffer Status Reporting (BSR) in fifth generation wireless communication system is described. In NR, BSR procedure is used to provide the serving gNB with information about UL data volume in the MAC entity. RRC configures the following parameters to control the BSR:

- periodicBSR-Timer;

- retxBSR-Timer;

- logicalChannelSR-DelayTimerApplied;

- logicalChannelSR-DelayTimer;

- logicalChannelSR-Mask;

- logicalChannelGroup.

Each logical channel may be allocated to a logical channel group (LCG) using the logicalChannelGroup. The maximum number of LCGs is eight. A BSR shall be triggered if any of the following events occur:

- UL data, for a logical channel which belongs to an LCG, becomes available to the MAC entity; and either

　　- this UL data belongs to a logical channel with higher priority than the priority of any logical channel containing available UL data which belong to any LCG; or

　　- none of the logical channels which belong to an LCG contains any available UL data.

in which case the BSR is referred below to as 'Regular BSR';

- UL resources are allocated and number of padding bits is equal to or larger than the size of the Buffer Status Report MAC CE plus its subheader, in which case the BSR is referred below to as 'Padding BSR';

- retxBSR-Timer expires, and at least one of the logical channels which belong to an LCG contains UL data, in which case the BSR is referred below to as 'Regular BSR';

- periodicBSR-Timer expires, in which case the BSR is referred below to as 'Periodic BSR'.

For Regular BSR, the MAC entity shall:

1> if the BSR is triggered for a logical channel for which logicalChannelSR-DelayTimerApplied with value true is configured by upper layers:

　　2> start or restart the logicalChannelSR-DelayTimer.

1> else:

　　2> if running, stop the logicalChannelSR-DelayTimer.

For Regular and Periodic BSR, the MAC entity shall:

1> if more than one LCG has data available for transmission when the MAC PDU containing the BSR is to be built:

　　2> report Long BSR for all LCGs which have data available for transmission.

1> else:

　　2> report Short BSR.

For Padding BSR, the MAC entity shall:

1> if the number of padding bits is equal to or larger than the size of the Short BSR plus its subheader but smaller than the size of the Long BSR plus its subheader:

　　2> if more than one LCG has data available for transmission when the BSR is to be built:

　　　　3> if the number of padding bits is equal to the size of the Short BSR plus its subheader:

　　　　　　4> report Short Truncated BSR of the LCG with the highest priority logical channel with data available for transmission.

　　　　3> else:

　　　　　　4> report Long Truncated BSR of the LCG(s) with the logical channels having data available for transmission following a decreasing order of the highest priority logical channel (with or without data available for transmission) in each of these LCG(s), and in case of equal priority, in increasing order of LCG ID.

　　2> else:

　　　　3> report Short BSR.

1> else if the number of padding bits is equal to or larger than the size of the Long BSR plus its subheader:

　　2> report Long BSR for all LCGs which have data available for transmission.

For BSR triggered by retxBSR-Timer expiry, the MAC entity considers that the logical channel that triggered the BSR is the highest priority logical channel that has data available for transmission at the time the BSR is triggered.

The MAC entity shall:

1> if the Buffer Status reporting procedure determines that at least one BSR has been triggered and not cancelled:

　　2> if UL-SCH resources are available for a new transmission and the UL-SCH resources can accommodate the BSR MAC CE plus its subheader as a result of logical channel prioritization:

　　　　3> instruct the Multiplexing and Assembly procedure to generate the BSR MAC CE(s);

　　　　3> start or restart periodicBSR-Timer except when all the generated BSRs are long or short Truncated BSRs;

　　　　3> start or restart retxBSR-Timer.

　　2> if a Regular BSR has been triggered and logicalChannelSR-DelayTimer is not running:

　　　　3> if there is no UL-SCH resource available for a new transmission; or

　　　　3> if the MAC entity is configured with configured uplink grant(s) and the Regular BSR was triggered for a logical channel for which logicalChannelSR-Mask is set to false; or

　　　　3> if the UL-SCH resources available for a new transmission do not meet the LCP mapping restrictions configured for the logical channel that triggered the BSR:

　　　　　　4> trigger a Scheduling Request.

A MAC PDU shall contain at most one BSR MAC CE, even when multiple events have triggered a BSR. The Regular BSR and the Periodic BSR shall have precedence over the padding BSR.

The MAC entity shall restart retxBSR-Timer upon reception of a grant for transmission of new data on any UL-SCH.

All triggered BSRs may be cancelled when the UL grant(s) can accommodate all pending data available for transmission but is not sufficient to additionally accommodate the BSR MAC CE plus its subheader. All BSRs triggered prior to MAC PDU assembly shall be cancelled when a MAC PDU is transmitted and this PDU includes a Long or Short BSR MAC CE which contains buffer status up to (and including) the last event that triggered a BSR prior to the MAC PDU assembly.

Embodiments of the disclosure will be described in detail with reference to the accompanying drawings. A base station refers to an entity that allocates resources to a terminal, and may be at least one of a gNode B, a gNB, an eNode B, a node B, a base station (BS), a radio access unit, a base station controller, or a node on a network. A terminal may include user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. Although embodiments of the disclosure will be described with reference to a 5G system as an example, embodiments of the disclosure are also applicable to other communication systems having similar technical backgrounds or channel types. For example, mobile communication technologies developed after 5G may be included therein. Therefore, embodiments of the disclosure are also applicable to other communication systems through a partial modification without substantially deviating from the scope of the disclosure as deemed by those skilled in the art. The embodiments of the disclosure described hereinafter may be applied simultaneously or in combination.

Extended Reality (XR) is a term for different types of realities and refers to all real-and-virtual combined environments and human-machine interactions generated by computer technology and wearables. The XR includes following representative forms and the areas interpolated among them: Augmented Reality (AR); Mixed Reality (MR); Virtual Reality (VR). In order to enhance the scheduling of uplink resources for XR, the following improvements are envisioned:

- One or more additional buffer status (BS) table(s) to reduce the quantisation errors in BSR reporting (e.g. for high bit rates);

- Delay knowledge of buffered data, consisting of e.g. remaining time, and distinguishing how much data is buffered for which delay. Data volume information associated with delay information e.g. remaining time is introduced. Data volume information associated with delay information may correspond to Delay-aware buffer status discussed below. It is to be determined whether the delay information is reported as part of BSR or as a new MAC CE. Also, how the delay information can be up-to-date considering e.g. scheduling and transmission delays needs to be investigated further.

- Additional BSR triggering conditions to allow timely availability of buffer status information may be investigated further

A new buffer status MAC CE or existing MAC CE may be defined to report remaining delivery time. This MAC CE may include at least one of the followings:

ㆍlogical channel (LCH) identifier (ID), shortest remaining delivery time amongst all the frames in the buffer of this LCH

ㆍLCG ID, shortest remaining delivery time amongst all the frames in the buffer of LCHs of this LCG

ㆍamount/size of data that should be delivered within the remaining delivery time may also be added

ㆍOnly reports the amount of data that fulfills 1) upper bound and/or 2) lower bound of remaining time if configured. It means that there is data whose remaining time is lower than a threshold. In other words, if the remaining time is lower/higher than a threshold, delay-aware buffer status is triggered.

Scheduling request (SR) is needed to obtain UL grant for transmitting Delay-aware buffer status (new medium access control (MAC) control element (CE) or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay is triggered). Several aspects of SR such as SR triggering condition; Whether to use existing SR config (i.e. same as one configured for BSR) or SR config to use for this new MAC CE is signaled by gNB in RRC signaling (i.e. higher layer signaling); SR cancellation criteria for new SR needs to be defined; RA cancellation criteria for new SR needs to be defined.

According to an embodiment of the disclosure, a UE is configured/allowed to transmit delay-aware buffer status by gNB using RRCReconfiguration message (i.e. higher layer signaling). The UE may indicate its capability to support delay aware buffer status to gNB using UE capability information message.

According to an embodiment of the disclosure, a new MAC CE or the delay aware buffer status MAC CE of MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay, may be triggered by UE/MAC entity upon occurrence of certain event.

According to an embodiment of the disclosure, upon triggering of delay-aware buffer status reporting, SR for delay-aware buffer status reporting may be triggered (as explained later). For triggered SR for delay-aware buffer status reporting, SR is transmitted on PUCCH resource using the SR configuration for delay-aware buffer status reporting or random access channel (RACH) (i.e. RACH procedure) is initiated. For example, the RACH is initiated if SR configuration for delay-aware buffer status reporting is not signalled or valid PUCCH resources are not available for SR transmission. Upon triggering of delay-aware buffer status reporting, UE generates and transmits the delay-aware buffer status (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay) to gNB. Triggered SR or RACH procedure for delay-aware buffer status reporting may be cancelled based on certain condition(s) as explained later.

SR Trigger for delay-aware buffer status reporting

Option 1:

Figure 1 illustrates an example method performed by a UE according to an embodiment of the disclosure. Figure 1 illustrates a method according to option 1 for the SR trigger for delay-aware buffer status reporting according to an embodiment of the disclosure. Various modifications may be made to the method illustrated in the flowcharts of Figure 1. For example, although shown as a series of operations, various operations in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, operations may be omitted or replaced with other operations.

Referring Figure 1, the UE is configured/allowed to transmit delay-aware buffer status by gNB via RRCReconfiguration message (i.e. higher layer signaling) (101). The UE determines/identifies that delay aware buffer status is triggered (103). The UE determines/identifies whether UL-SCH resources are available for a new transmission and if the UL-SCH resources can accommodate the delay-aware buffer status MAC CE plus its subheader as a result of LCP (105). If the UL-SCH resources are available for a new transmission and if the UL-SCH resources can accommodate the delay-aware buffer status MAC CE plus its subheader as a result of LCP, the UE generates the delay-aware buffer status MAC CE (107). Else, the UE triggers the SR for delay-aware buffer status reporting (109). The SR may be transmitted on PUCCH resource using the SR configuration for (delay-aware) buffer status reporting or if valid PUCCH resources for SR transmission are not available RACH may be initiated (111).

In one method of the disclosure, MAC entity in the UE determines whether to trigger SR or not according to the following operation:

1> if the delay-aware buffer status (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay) has been triggered and not cancelled (103):

　　2> if UL-SCH resources are available for a new transmission and if the UL-SCH resources can accommodate the delay-aware buffer status MAC CE (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay) plus its subheader as a result of LCP (105):

　　　　3> instruct the Multiplexing and Assembly procedure to generate the delay-aware buffer status MAC CE (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay) (107).

　　2> else:

　　　　3> trigger the SR for delay-aware buffer status reporting (109).

Option 2:

Figure 2 illustrates an example method performed by a UE according to an embodiment of the disclosure. Figure 2 illustrates a method according to option 2 for the SR trigger for delay-aware buffer status reporting according to an embodiment of the disclosure. Various modifications may be made to the method illustrated in the flowcharts of Figure 2. For example, although shown as a series of operations, various operations in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, operations may be omitted or replaced with other operations.

Referring Figure 2, the UE is configured/allowed to transmit delay-aware buffer status by gNB via RRCReconfiguration message (i.e. higher layer signaling) (201). The UE determines/identifies that delay aware buffer status is triggered (203). The UE determines/identifies whether UL-SCH resources are available for a new transmission within a timer interval (i.e. not later than a threshold since the trigger) and if the UL-SCH resources can accommodate the delay-aware buffer status MAC CE and its subheader as a result of LCP (205). If the UL-SCH resources can accommodate the delay-aware buffer status MAC CE and its subheader as a result of LCP, the UE generates the delay-aware buffer status MAC CE (207). Else the UE triggers the SR for delay-aware buffer status reporting (209). The SR may transmitted on PUCCH resource using the SR configuration for (delay-aware) buffer status reporting or if valid PUCCH resources for SR transmission are not available RACH may be initiated (211).

In another method of the disclosure, MAC entity in the UE determines whether to trigger SR or not according to the following operation:

1> if the delay-aware buffer status (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay) has been triggered and not cancelled (203):

　　2> if UL-SCH resources are available for a new transmission within a timer interval (i.e. not later than a threshold since the trigger) and if the UL-SCH resources can accommodate the delay-aware buffer status MAC CE (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay) plus its subheader as a result of LCP (205):

　　　　3> instruct the Multiplexing and Assembly procedure to generate the delay-aware buffer status (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay) (207).

　　2> else:

　　　　3> trigger the SR for delay-aware buffer status reporting.

In this method the threshold may be signalled by gNB in RRC message (e.g. system information (SI) or RRCReconfiguration message) or may be pre-defined.

SR Configuration for delay-aware buffer status reporting

Option 1: In one method of the disclosure, SR configuration for delay-aware buffer status reporting is signalled by network in RRCReconfiguration. MAC-CellGroupConfig information element (IE) in RRCReconfiguration message may include scheduling request ID which identifies the Scheduling Request configuration from a list of Scheduling Request configurations and the Scheduling Request Resource configuration from a list of Scheduling Request Resource configurations to be used for transmitting SR for delay-aware buffer status reporting:

ㆍschedulingRequestID-DelayAwareBSR-r18 SchedulingRequestId

A list of Scheduling Request configurations is signalled in RRCReconfiguration where each configuration is identified by SchedulingRequestId. Scheduling Request configuration includes at least one of sr-ProhibitTimer (i.e. a timer for SR transmission on PUCCH) or sr-TransMax (i.e. the maximum number of SR transmissions)

A list of Scheduling Request Resource configurations is signalled in RRCReconfiguration where each configuration is identified by SchedulingRequestId. Scheduling Request Resource configuration includes PUCCH resources.

In this method when SR for delay-aware buffer status reporting is triggered, SR is transmitted in PUCCH resource signaled in Scheduling Request Resource configuration identified by schedulingRequestID-DelayAwareBSR-r18. sr-ProhibitTimer and sr-TransMax signaled in Scheduling Request configuration identified by schedulingRequestID-DelayAwareBSR-r18 is applied to SR procedure triggered for delay-aware buffer status reporting.

Option 2: In another method of the disclosure, SR configuration for delay-aware buffer status reporting is signalled by network in RRCReconfiguration. LogicalChannelConfig IE in RRCReconfiguration message may include scheduling request ID which identifies the Scheduling Request configuration from a list of Scheduling Request configurations and the Scheduling Request Resource configuration from a list of Scheduling Request Resource configurations to be used for transmitting SR for delay-aware buffer status reporting:

ㆍschedulingRequestID-DelayAwareBSR-r18 SchedulingRequestId

A list of Scheduling Request configurations is signalled in RRCReconfiguration where each configuration is identified by SchedulingRequestId. Scheduling Request configuration includes at least one of sr-ProhibitTimer or sr-TransMax

In this method when SR for delay-aware buffer status reporting is triggered, SR is transmitted in PUCCH resource signaled in Scheduling Request Resource configuration identified by schedulingRequestID-DelayAwareBSR-r18 in logical channel configuration of LCH which triggered the SR. sr-ProhibitTimer and sr-TransMax signalled in Scheduling Request configuration identified by schedulingRequestID-DelayAwareBSR-r18 in logical channel configuration of LCH which triggered the SR is applied to SR procedure triggered for delay-aware buffer status reporting.

Option 3: In another method of the disclosure, SR configuration for delay-aware buffer status reporting is same as the one signalled by network (i.e. gNB) in RRCReconfiguration for BSR.

Option 4: In another method of the disclosure, if SR configuration for delay-aware buffer status reporting is not signalled, UE applies the SR configuration signalled for BSR as the SR configuration for delay-aware buffer status reporting.

Option 5: In another method of the disclosure, if SR configuration for delay-aware buffer status reporting is not signalled, upon triggering SR for delay-aware buffer status reporting, UE initiates RACH.

Option 6: In another method of the disclosure, if SR configuration for delay-aware buffer status reporting is not signalled, UE does not trigger SR for delay-aware buffer status reporting. Triggering procedure may be as follows:

1> if the delay-aware buffer status (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay) has been triggered and not cancelled:

　　2> if UL-SCH resources are available for a new transmission and if the UL-SCH resources can accommodate the delay-aware buffer status MAC CE (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay) plus its subheader as a result of LCP:

　　　　3> instruct the Multiplexing and Assembly procedure to generate the delay-aware buffer status MAC CE (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay).

　　2> else if SR configuration for delay-aware buffer status reporting is signalled/configured:

　　　　3> trigger the SR for delay-aware buffer status reporting.

Alternate:

　　2> if UL-SCH resources are available for a new transmission within a timer interval (i.e. not later than a threshold since the trigger) and if the UL-SCH resources can accommodate the delay-aware buffer status MAC CE (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay) plus its subheader as a result of LCP:

　　　　3> instruct the Multiplexing and Assembly procedure to generate the delay-aware buffer status (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay).

　　　　3> trigger the SR for delay-aware buffer status reporting.

SR Cancellation for delay-aware buffer status reporting

If the SR was triggered for delay-aware buffer status reporting and a MAC PDU is transmitted and the MAC PDU includes delay-aware buffer status reporting MAC CE (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay):

ㆍcancel the pending SR and stop the corresponding sr-ProhibitTimer, if running.

All pending SR(s) for delay-aware buffer status reporting shall be cancelled and each respective sr-ProhibitTimer shall be stopped when the UL grant(s) can accommodate all pending data available for transmission.

All pending SR(s) for delay-aware buffer status reporting shall be cancelled and each respective sr-ProhibitTimer shall be stopped when the UL grant(s) can accommodate all pending data to be reported by the triggered delay-aware buffer status report MAC CE (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay).

All pending SR(s) for delay-aware buffer status reporting shall be cancelled and each respective sr-ProhibitTimer shall be stopped when there is no data to be reported by delay-aware buffer status report MAC CE (new MAC CE or the delay aware buffer status MAC CE or MAC CE including the delay knowledge of buffered data e.g. remaining time and distinguishing how much data is buffered for which delay).

Random access (RA) Cancellation for delay-aware buffer status reporting

The MAC entity stops, if any, ongoing Random Access procedure due to a pending SR for delay-aware buffer status reporting, which has no valid PUCCH resources configured, if:

- a MAC PDU is transmitted using a UL grant other than a UL grant provided by Random Access Response or a UL grant determined for the transmission of the message A (MSGA) payload, and this PDU includes a delay-aware buffer status reporting MAC CE which contains delay aware buffer status up to (and including) the last event that triggered a delay-aware buffer status reporting prior to the MAC PDU assembly; or

- the UL grant(s) can accommodate all pending data available for transmission.

Handling overlapping of PUCCH resources

There are several types of PUCCH resource, for example:

ㆍPUCCH resources for BSR

ㆍPUCCH resources for Delay aware buffer status reporting

ㆍPUCCH resources for SCell BFR (beam failure reporting)

ㆍPUCCH resources for beam failure detection reference signal (BFD-RS) set of serving cell

ㆍPUCCH resources for listen before talk (LBT) failure

In case PUCCH resources for Delay aware buffer status reporting overlaps (e.g. in time domain, frequency resource may still be separate) with PUCCH resources for any other pending SR:

ㆍPUCCH resources for Delay aware buffer status reporting is prioritized and UE transmits SR for Delay aware buffer status reporting

(Alt) In case PUCCH resources for Delay aware buffer status reporting overlaps with PUCCH resources for any other pending SR other than those triggered for BSR

(Alt) In case PUCCH resources for Delay aware buffer status reporting overlaps with PUCCH resources for BFD-RS set of serving cell

ㆍPUCCH resources for BFD-RS set of serving cell is prioritized and UE transmits SR for BFR of BFD-RS set of serving cell

(Alt) In case PUCCH resources for Delay aware buffer status reporting overlaps with PUCCH resources for BFD-RS set of SpCell

ㆍPUCCH resources for BFD-RS set of serving cell is prioritized and UE transmits SR for BFR of BFD-RS set of SpCell

(Alt) In case PUCCH resources for Delay aware buffer status reporting overlaps with PUCCH resources for LBT failure

ㆍPUCCH resources for LBT failure of serving cell is prioritized and UE transmits SR for LBT failure

(Alt) In case PUCCH resources for Delay aware buffer status reporting overlaps with PUCCH resources for LBT failure of SpCell

ㆍPUCCH resources for LBT failure of serving cell is prioritized and UE transmits SR for LBT failure of SpCell

Figure 3 illustrates an electronic device according to embodiments of the present disclosure.

Referring to the Figure 3, the electronic device 300 may include a processor 310, a transceiver 320 and a memory 330. However, all of the illustrated components are not essential. The electronic device 300 may be implemented by more or less components than those illustrated in Figure 3. In addition, the processor 310 and the transceiver 320 and the memory 330 may be implemented as a single chip according to another embodiment.

The electronic device 300 may correspond to the UE described above.

The aforementioned components will now be described in detail.

The processor 310 may include one or more processors or other processing devices that control the proposed function, process, and/or method. Operation of the electronic device 300 may be implemented by the processor 310.

The transceiver 320 may include a RF transmitter for up-converting and amplifying a transmitted signal, and a RF receiver for down-converting a frequency of a received signal. However, according to another embodiment, the transceiver 320 may be implemented by more or less components than those illustrated in components.

The transceiver 320 may be connected to the processor 310 and transmit and/or receive a signal. The signal may include control information and data. In addition, the transceiver 320 may receive the signal through a wireless channel and output the signal to the processor 310. The transceiver 320 may transmit a signal output from the processor 310 through the wireless channel.

The memory 330 may store the control information or the data included in a signal obtained by the electronic device 300. The memory 330 may be connected to the processor 310 and store at least one instruction or a protocol or a parameter for the proposed function, process, and/or method. The memory 330 may include read-only memory (ROM) and/or random access memory (RAM) and/or hard disk and/or CD-ROM and/or DVD and/or other storage devices.

Figure 4 illustrates a base station according to embodiments of the present disclosure.

Referring to the Figure 4, the base station 400 may include a processor 410, a transceiver 420 and a memory 430. However, all of the illustrated components are not essential. The base station 400 may be implemented by more or less components than those illustrated in Figure 4. In addition, the processor 410 and the transceiver 420 and the memory 430 may be implemented as a single chip according to another embodiment.

The base station 400 may correspond to the gNB described above.

The aforementioned components will now be described in detail.

The processor 410 may include one or more processors or other processing devices that control the proposed function, process, and/or method. Operation of the base station 400 may be implemented by the processor 410.

The transceiver 420 may include a RF transmitter for up-converting and amplifying a transmitted signal, and a RF receiver for down-converting a frequency of a received signal. However, according to another embodiment, the transceiver 420 may be implemented by more or less components than those illustrated in components.

The transceiver 420 may be connected to the processor 410 and transmit and/or receive a signal. The signal may include control information and data. In addition, the transceiver 420 may receive the signal through a wireless channel and output the signal to the processor 410. The transceiver 420 may transmit a signal output from the processor 410 through the wireless channel.

The memory 430 may store the control information or the data included in a signal obtained by the base station 400. The memory 430 may be connected to the processor 410 and store at least one instruction or a protocol or a parameter for the proposed function, process, and/or method. The memory 430 may include read-only memory (ROM) and/or random access memory (RAM) and/or hard disk and/or CD-ROM and/or DVD and/or other storage devices.

The methods according to various embodiments described in the claims or the specification of the disclosure may be implemented by hardware, software, or a combination of hardware and software.

When the methods are implemented by software, a computer-readable storage medium for storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium may be configured for execution by one or more processors within the electronic device. The at least one program may include instructions that cause the electronic device to perform the methods according to various embodiments of the disclosure as defined by the appended claims and/or disclosed herein.

The programs (software modules or software) may be stored in non-volatile memories including a random access memory and a flash memory, a read only memory (ROM), an electrically erasable programmable read only memory (EEPROM), a magnetic disc storage device, a compact disc-ROM (CD-ROM), digital versatile discs (DVDs), or other type optical storage devices, or a magnetic cassette. Alternatively, any combination of some or all of them may form a memory in which the program is stored. Further, a plurality of such memories may be included in the electronic device.

In addition, the programs may be stored in an attachable storage device which may access the electronic device through communication networks such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), and Storage Area Network (SAN) or a combination thereof. Such a storage device may access the electronic device via an external port. Further, a separate storage device on the communication network may access a portable electronic device.

In the above-described detailed embodiments of the disclosure, an element included in the disclosure is expressed in the singular or the plural according to presented detailed embodiments. However, the singular form or plural form is selected appropriately to the presented situation for the convenience of description, and the disclosure is not limited by elements expressed in the singular or the plural. Therefore, either an element expressed in the plural may also include a single element or an element expressed in the singular may also include multiple elements.

The embodiments of the disclosure described and shown in the specification and the drawings are merely specific examples that have been presented to easily explain the technical contents of the disclosure and help understanding of the disclosure, and are not intended to limit the scope of the disclosure. That is, it will be apparent to those skilled in the art that other variants based on the technical idea of the disclosure may be implemented. Furthermore, the above respective embodiments may be employed in combination, as necessary. For example, a part of one embodiment of the disclosure may be combined with a part of another embodiment to operate a base station and a terminal. As an example, a part of embodiment 1 of the disclosure may be combined with a part of embodiment 2 to operate a base station and a terminal.

In the drawings in which methods of the disclosure are described, the order of the description does not always correspond to the order in which steps of each method are performed, and the order relationship between the steps may be changed or the steps may be performed in parallel.

Alternatively, in the drawings in which methods of the disclosure are described, some elements may be omitted and only some elements may be included therein without departing from the essential spirit and scope of the disclosure.

Any of the above variation embodiments can be utilized independently or in combination with at least one other variation embodiment. The above flowchart(s) illustrate example methods that can be implemented in accordance with the principles of the present disclosure and various changes could be made to the methods illustrated in the flowcharts herein. For example, while shown as a series of steps, various steps in each figure could overlap, occur in parallel, occur in a different order, or occur multiple times. In another example, steps may be omitted or replaced by other steps.

Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims. None of the descriptions in this application should be read as implying that any particular element, step, or function is an essential element that must be included in the claims scope. The scope of patented subject matter is defined by the claims.

Claims

A method performed by a user equipment (UE) in a communication system, the method comprising:

identifying that reporting of delay information associated with buffered data is triggered;

identifying whether uplink shared channel (UL-SCH) resources are available for a new transmission, and the UL-SCH resources are available to accommodate (i) a medium access control (MAC) control element (CE) for the reporting of delay information and (ii) a subheader of the MAC CE for the reporting of delay information;

generating the MAC CE for the reporting of delay information, in case that the UL-SCH resources are available for the new transmission, and the UL-SCH resources are available to accommodate the MAC CE for the reporting of delay information and the subheader of the MAC CE; and

transmitting, to a base station, the MAC CE for the reporting of delay information.
The method of claim 1, further comprising:

in case that the UL-SCH resources are unavailable for the new transmission, or the UL-SCH resources are unavailable to accommodate the MAC CE for the reporting of delay information and the subheader of the MAC CE, triggering a scheduling request (SR).
The method of claim 2, further comprising:

in case that (i) all data associated with the reporting of delay information is transmitted or (ii) a MAC protocol data unit (PDU) is transmitted and the MAC PDU includes a MAC CE including the delay information,

cancelling the SR which is pending; and

stopping sr-ProhibitTimer which is running.
The method of claim 1, wherein whether the UL-SCH resources are available for the new transmission and the UL-SCH resources are available to accommodate the MAC CE for the reporting of delay information and the subheader for the MAC CE is identified, in case that the triggered reporting of delay information is not cancelled.
The method of claim 1, wherein whether the UL-SCH resources are available to accommodate the MAC CE for the reporting of the delay information and the subheader for the MAC CE is identified as a result of logical channel prioritization.
The method of claim 1, wherein the MAC CE for the reporting of delay information includes remaining time associated with the buffered data.
A user equipment (UE) in a communication system, the UE comprising:

a transceiver; and

a processor coupled with the transceiver and configured to:

identify that reporting of delay information associated with buffered data is triggered;

identify whether uplink shared channel (UL-SCH) resources are available for a new transmission, and the UL-SCH resources are available to accommodate (i) a medium access control (MAC) control element (CE) for the reporting of delay information and (ii) a subheader of the MAC CE for the reporting of delay information;

generate the MAC CE for the reporting of delay information, in case that the UL-SCH resources are available for the new transmission, and the UL-SCH resources are available to accommodate the MAC CE for the reporting of delay information and the subheader of the MAC CE; and

transmit, to a base station, the MAC CE for the reporting of delay information.
The UE of claim 7, wherein the processor is further configured to:

in case that the UL-SCH resources are unavailable for the new transmission, or the UL-SCH resources are unavailable to accommodate the MAC CE for the reporting of delay information and the subheader of the MAC CE, trigger a scheduling request (SR).
The UE of claim 8, wherein the processor is further configured to:

in case that (i) all data associated with the reporting of delay information is transmitted or (ii) a MAC protocol data unit (PDU) is transmitted and the MAC PDU includes a MAC CE including the delay information,

cancel the SR which is pending; and

stop sr-ProhibitTimer which is running.
The UE of claim 7, wherein whether the UL-SCH resources are available for the new transmission and the UL-SCH resources are available to accommodate the MAC CE for the reporting of delay information and the subheader for the MAC CE is identified, in case that the triggered reporting of delay information is not cancelled.
The UE of claim 7, wherein whether the UL-SCH resources are available to accommodate the MAC CE for the reporting of the delay information and the subheader for the MAC CE is identified as a result of logical channel prioritization.
The UE of claim 7, wherein the MAC CE for the reporting of delay information includes remaining time associated with the buffered data.
A method performed by a base station in a communication system, the method comprising:

transmitting, to a user equipment (UE), a radio resource control (RRC) message including configuration information on reporting of delay information associated with buffered data; and

receiving, from the UE, a medium access control (MAC) control element (CE) for the reporting of delay information based on uplink shared channel (UL-SCH) resources, in case that the UL-SCH resources are available for a new transmission of the UE and the UL-SCH resources are available to accommodate the MAC CE for the reporting of delay information and (ii) a subheader of the MAC CE for the reporting of delay information.
The method of claim 13, further comprising:

in case that the UL-SCH resources are unavailable for the new transmission, or the UL-SCH resources are unavailable to accommodate the MAC CE for the reporting of delay information and the subheader of the MAC CE, receiving a scheduling request (SR).
A base station in a communication system, the base station comprising:

a transceiver; and

a processor coupled with the transceiver and configured to:

transmit, to a user equipment (UE), a radio resource control (RRC) message including configuration information on reporting of delay information associated with buffered data; and

receive, from the UE, a medium access control (MAC) control element (CE) for the reporting of delay information based on uplink shared channel (UL-SCH) resources, in case that the UL-SCH resources are available for a new transmission of the UE and the UL-SCH resources are available to accommodate the MAC CE for the reporting of delay information and (ii) a subheader of the MAC CE for the reporting of delay information.