Method and apparatus for configured licension type 1 for vehicle network (V2X) communication processing

Abstract

The present disclosure provides a communication method and system for converging Internet of Things (IoT) technology with a 5th-Generation (5G) communication system that supports higher data rates beyond a 4th-Generation (4G) system. The communication method and system can be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A method performed by a terminal in a wireless communication system is provided. The method includes identifying that a sidelink channel state information (SL-CSI) report is triggered; identifying whether an SL resource is allocated for a new transmission; performing logic channel priority setting on the SL resources; and determining whether to trigger a scheduling request for the SL-CSI report based on a result of the logical channel priority setting.

Description

Technical Field

[0001] The present disclosure relates to a method for configuring a license type 1 for vehicle-to-everything (V2X) communication processing. Background Art

[0002] In order to meet the demand for wireless data services that has increased since the deployment of the fourth generation (4G) communication system, efforts have been made to develop and improve the fifth generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also referred to as a "super 4G network" or a "post-long term evolution (LTE) system". The 5G wireless communication system supports not only lower frequency bands, but also higher frequency (millimeter wave) bands, such as 10 GHz to 100 GHz bands, in order to achieve higher data rates. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple input multiple output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technology are considered in the design of the 5G wireless communication system. In addition, in the 5G communication system, development of system network improvements is being carried out based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, cooperative communications, coordinated multi-point (CoMP), receiving-end interference elimination, etc. In the 5G system, frequency and quadrature amplitude modulation (FQAM) as a combination of hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM), sliding window superposition coding (SWSC) as advanced coded modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse coded multiple access (SCMA) as advanced access technologies have also been developed.

[0003] In a similar vein, the Internet, a human-centered connected network where humans generate and consume information, is now developing into the Internet of Things (IoT) where distributed entities such as things exchange and process information without human intervention. The Internet of Everything (IoE) has also emerged as a combination of IoT technology and big data processing technology through connection with a cloud server. Since IoT implementation requires technical elements such as "sensing technology", "wired / wireless communication and network infrastructure", "service interface technology, and "security technology", research on sensor networks, machine-to-machine (M2M) communication, machine-type communication (MTC), etc. has begun. This IoT environment can provide smart Internet technology services that create new value for human life by collecting and analyzing data generated between connected things. In this case, through the integration and combination between existing information technology (IT) and various industrial applications, IoT can be applied in various fields including smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, health care, smart devices, and advanced medical services.

[0004] At the same time, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, MTC, and M2M communications can be implemented through beamforming, MIMO, and array antennas. Cloud RAN as an application of the above-mentioned big data processing technology can also be considered an example of the fusion between 5G technology and IoT technology.

[0005] In recent years, several broadband wireless technologies have been developed to meet the increasing number of broadband users and to provide more and better applications and services such as the following. The second generation (2G) wireless communication system has been developed to provide voice services while ensuring the mobility of users. The third generation (3G) wireless communication system supports voice services and data services. The 4G wireless communication system has been developed to provide high-speed data services. However, the 4G wireless communication system is currently suffering from a lack of resources to meet the growing demand for high-speed data services. Therefore, the 5G wireless communication system (also known as the next generation radio or new radio (NR)) is being developed to meet the growing demand for various services with different requirements (such as high-speed data services, support for ultra-reliability and low-latency applications).

[0006] In addition, 5G wireless communication systems are expected to handle different use cases with completely different requirements in terms of data rate, latency, reliability, mobility, etc. However, it is expected that the design of the air interface of the 5G wireless communication system will be flexible enough to serve user equipment (UE) with completely different capabilities depending on the use case and the market segment that the UE provides services to the end user. Exemplary use cases that the 5G wireless communication system is expected to address include enhanced mobile broadband (eMBB), massive machine type communication (m-MTC), ultra-reliable low latency communication (URLL), etc. The eMBB requirements (e.g., data rates of tens of Gbps, low latency, high mobility, etc.) address the market segment representing wireless broadband subscribers who need to connect to the Internet anytime and anywhere. The m-MTC requirements (e.g., very high connection density, infrequent data transmission, very long battery life, low mobility address, etc.) address the market segment representing the IoT / IoE envisioned connections of billions of devices. The URLL requirements (e.g., very low latency, very high reliability, variable mobility, etc.) address the market segment representing industrial automation applications and vehicle-to-vehicle / vehicle-to-infrastructure communications that are foreseen as one of the driving factors for autonomous vehicles.

[0007] In a 5G wireless communication system operating in a higher frequency (millimeter wave) band, UE and next generation node B (gNB) communicate with each other using beamforming. Beamforming technology is used to mitigate propagation path loss and increase the propagation distance of communication on a higher frequency band. Beamforming enhances the transmission and reception performance using high-gain antennas. Beamforming can be divided into transmit (TX) beamforming performed at the transmitting end and receive (RX) beamforming performed at the receiving end. Generally, TX beamforming increases directivity by using multiple antennas to densely position in a specific direction by allowing the area reached by propagation. In this case, the set of multiple antennas can be referred to as an antenna array, and each antenna included in the array can be referred to as an array element. The antenna array can be configured in various forms, such as a linear array, a planar array, and the like. The use of TX beamforming results in an increase in the directivity of the signal, thereby increasing the propagation distance. In addition, since the signal is hardly transmitted in directions other than the directional direction, the signal interference acting on the other receiving end is significantly reduced. The receiving end can perform beamforming on the RX signal by using an RX antenna array. RX beamforming increases the strength of RX signals transmitted in a specific direction by allowing propagation to be concentrated in a specific direction, and excludes signals transmitted in directions other than the specific direction from the RX signal, thereby providing the effect of blocking interference signals. By using beamforming technology, the transmitter can generate multiple transmit (TX) beam patterns in different directions. Each of these TX beam patterns may also be referred to as a TX beam. Because each narrow TX beam provides coverage to a portion of the cell, wireless communication systems operating at high frequencies use multiple narrow TX beams to transmit signals in the cell. The narrower the TX beam, the higher the antenna gain, and therefore the greater the propagation distance of the signal transmitted using beamforming. The receiver can also generate multiple receive (RX) beam patterns in different directions. Each of these RX beam patterns may also be referred to as an RX beam.

[0008] The 5G wireless communication system supports independent operation mode and dual connection (DC) mode. In DC, multiple RX / TX UEs can be configured to utilize resources provided by two different nodes (or Node B (NB)) connected via a non-ideal backhaul. One node acts as a master node (MN) and the other node acts as a secondary node (SN). MN and SN are connected via a network interface, and at least MN is connected to the core network. NR also supports multi-radio access technology (RAT) DC (MR-DC) operation, whereby the UE in radio resource control (RRC)_CONNECTED is configured to utilize radio resources provided by two different schedulers, which are located in two different nodes connected via a non-ideal backhaul and provide evolved universal mobile telecommunications system (UMTS) terrestrial radio access (E-UTRA) (ie if the node is a next generation (ng) evolved Node B (eNB)) or NR access (ie if the node is a gNB).

[0009] In NR, for UEs in RRC_CONNECTED without carrier aggregation (CA) / DC, there is only one serving cell including the primary cell (PCell). For UEs in RRC_CONNECTED with CA / DC, the term "serving cell" is used to refer to the set of cells including the specific cell (SpCell) and all secondary cells (SCells).

[0010] In NR, the term "Master Cell Group" (MCG) refers to a set of service cells associated with a MN, including a PCell and optionally one or more SCells. In NR, the term "Secondary Cell Group (SCG)" refers to a set of service cells associated with a SN, including a primary SCG cell (PSCell) and optionally one or more SCells. In NR, PCell refers to a service cell operating on the primary frequency in an MCG, in which the UE performs an initial connection establishment procedure or initiates a connection reestablishment procedure. In NR, for UEs configured with CA, an SCell is a cell that provides additional radio resources on top of the SpCell. PSCell refers to a service cell in an SCG, in which the UE performs a random access (RA) when performing a reconfiguration with a synchronization procedure. For DC operation, the term "SpCell" refers to the PCell of an MCG or the PSCell of an SCG, otherwise, the term "SpCell" refers to the PCell.

[0011] In the 5G wireless communication system, the physical downlink control channel (PDCCH) is used to schedule downlink (DL) transmission on the physical downlink shared channel (PDSCH) and uplink (UL) transmission on the physical uplink shared channel (PUSCH), wherein the downlink control information (DCI) on the PDCCH includes: downlink allocation including at least the modulation and coding format, resource allocation and hybrid automatic repeat request (HARQ) information related to the DL-SCH; UL scheduling including at least the modulation and coding format, resource allocation and HARQ information related to the UL shared channel (SCH). In addition to scheduling, PDCCH can be used for: activation and deactivation of configured PUSCH transmissions for configured grants; activation and deactivation of PDSCH semi-persistent transmissions; notification of the time slot format to one or more user equipment UEs; notification of physical resource blocks (PRBs) and orthogonal frequency division multiplexing (OFDM) symbols to one or more UEs where the UE can assume no transmission for the UE; transmission of transmission power control (TPC) commands for PUCCH and PUSCH; transmission of one or more TPC commands for sounding reference signal (SRS) transmission for one or more UEs; switching the active bandwidth part (BWP) of the UE; initiating the RA process. The UE monitors a set of PDCCH candidates in the configured monitoring opportunities in one or more configured control resource sets (CORESETs) according to the corresponding search space configuration. A CORESET consists of a set of PRBs with a duration of 1-3 OFDM symbols. Resource unit resource element groups (REGs) and control channel elements (CCEs) are defined within a CORESET, and each CCE includes a set of REGs. The control channel is formed by CCE aggregation. Different code rates for control channels are achieved by aggregating different numbers of CCEs. Interleaved and non-interleaved CCE to REG mapping is supported in CORESET. Polarity coding is used for PDCCH. Each REG carrying PDCCH carries its own demodulation reference signal (DMRS). PDCCH uses quadrature phase shift keying (QPSK) modulation.

[0012] In a 5G wireless communication system, a list of search space configurations is sent by the gNB for each configured BWP, where each search configuration is uniquely identified by an identifier (ID). The IDs of search space configurations for specific purposes such as paging reception, system information (SI) reception, and random access response (RAR) reception are explicitly signaled by the gNB. In NR, the search space configuration includes the parameters Monitoring-periodicity-PDCCH-slot, Monitoring-offset-PDCCH-slot, Monitoring-symbols-PDCCH-within-slot, and duration. The UE uses the parameters PDCCH monitoring period (Monitoring-periodicity-PDCCH-slot), PDCCH monitoring offset (Monitoring-offset-PDCCH-slot), and PDCCH monitoring mode (Monitoring-symbols-PDCCH-in-slot) to determine the PDCCH monitoring timing within a timeslot. The PDCCH monitoring opportunity exists in slots 'x' to x+duration, where the slot with number 'x' in the radio frame with number 'y' satisfies the following equation:

[0013] (y*(number of slots in a radio frame)+x-Monitoring-offset-PDCCH-slot)mod(Monitoring-periodicity-PDCCH-slot)=0;

[0014] The starting symbol of the PDCCH monitoring opportunity in each slot with a PDCCH monitoring opportunity is given by Monitoring-symbols-PDCCH-within-slot. The length of the PDCCH monitoring opportunity (in symbols) is given in the CORESET associated with the search space. The search space configuration includes the ID of the CORESET configuration associated with it. A list of CORESET configurations for each configured BWP is signaled by the gNB, where each CORESET configuration is uniquely identified by an ID. Note that each radio frame has a duration of 10ms. A radio frame is identified by a radio frame number or a system frame number. Each radio frame includes several slots, where the number of slots in a radio frame and the slot duration depend on the subcarrier spacing (SCS). The number of slots in a radio frame and the slot duration of a radio frame for each supported SCS are predefined in NR. Each CORESET configuration is associated with a list of transmission configuration indicator (TCI) states. One DL reference signal (RS) ID (synchronization signal and physical broadcast channel (PBCH) block (SSB) or channel state information (CSI)-RS) is configured for each TCI state. The TCI state list corresponding to the CORESET configuration is sent by the gNB via RRC signaling. One TCI state in the TCI state list is activated and indicated by the gNB to the UE. The TCI state indicates the DL TX beam used by the gNB for PDCCH transmission in the PDCCH monitoring occasion of the search space (the DL TX beam is quasi co-located (QCLed) with the SSB / CSI-RS of the TCI state).

[0015] In 5G wireless communication systems, bandwidth adaptation (BA) is supported. With BA, the receiving and transmitting bandwidth of the UE does not have to be as large as the bandwidth of the cell and can be adjusted. The width can be commanded to change (for example, shrink during low activity to save power), the position can be moved in the frequency domain (for example, to increase scheduling flexibility), and the SCS can be commanded to change (for example, to allow different services). A subset of the total cell bandwidth of a cell is called a BWP. BA is implemented by configuring a BWP for an RRC-connected UE and telling the UE which of the currently configured BWPs is active. When BA is configured, the UE only needs to monitor the PDCCH on one active BWP, i.e. it does not have to monitor the PDCCH on the entire DL frequency of the serving cell. In the RRC connected state, for each configured serving cell (i.e. PCell or SCell), the UE is equipped with one or more DL BWPs and UL BWPs. For an activated serving cell, there is always an active UL BWP and DL BWP at any point in time. Use BWP switching of the serving cell to activate inactive BWPs and deactivate active BWPs one by one. BWP switching is controlled by the PDCCH indicating DL allocation or UL grant, by the bwp-InactivityTimer, by RRC signaling, or by the media access control (MAC) entity itself at the start of the RA process. When adding a SpCell or activating an SCell, the DL BWP and ULBWP indicated by firstActiveDownlinkBWP-Id and firstActiveUplinkBWP-Id, respectively, are active without receiving a PDCCH indicating DL allocation or UL grant. The active BWP for the serving cell is indicated by RRC or PDCCH. For unpaired spectrum, the DL BWP is paired with the UL BWP, and the BWP switching is common for both UL and DL. When the BWP inactivity timer expires, the UE switches the active DLBWP to the default DL BWP or the initial DL BWP (if the default DL BWP is not configured).

[0016] RA is supported in 5G wireless communication systems. RA is used to achieve UL time synchronization. RA is used during initial access, handover, RRC connection reestablishment process, scheduling request transmission, SCG addition / modification, beam failure recovery, and transmission of data or control information in UL by an unsynchronized UE in RRC connected state. Several types of RA procedures are supported.

[0017] Contention-based RA (CBRA): This is also known as 4-step CBRA. In this type of RA, the UE first sends a RA preamble (also known as Message 1 (Msg1)) and then waits for the RAR in the RAR window. The RAR is also known as Message 2 (Msg2). The gNB sends the RAR on the PDSCH. The PDCCH that schedules the PDSCH carrying the RAR is addressed with the RA Radio Network Temporary Identifier (RA-RNTI). The RA-RNTI identifies the time-frequency resource (also known as the physical RA channel (PRACH) opportunity, or PRACH TX opportunity, or RA channel (RACH) opportunity (RO)) of the RA preamble detected by the gNB. RA-RNTI is calculated as follows: RA-RNTI = 1 + s_id + 14 * t_id + 14 * 80 * f_id + 14 * 80 * 8 * ul_carrier_id, where s_id is the index of the first OFDM symbol of the PRACH opportunity where the UE has sent Msg1, i.e., the RA preamble; 0 ≤ s_id ≤ 14; t_id is the index of the first slot of the PRACH opportunity (0 ≤ t_id < 80); f_id is the index of the PRACH opportunity within the slot in the frequency domain (0 ≤ f_id ≤ 8), and ul_carrier_id is the UL carrier used for Msg1 transmission (0 for normal UL (NUL) carrier, 1 for secondary UL (SUL) carrier). Several RARs for various RA preambles detected by the gNB can be multiplexed by the gNB in ​​the same RAR MAC protocol data unit (PDU). If the RAR in the MAC PDU includes the RA preamble identifier (RAPID) of the RA preamble sent by the UE, then the RAR corresponds to a RA preamble transmission by that UE. If no RAR corresponding to its RA preamble transmission is received during the RAR window, and the UE has not sent a configured number of RA preambles (configured by the gNB in ​​the RACH configuration), then the UE returns to the first step, i.e. selecting a RA resource (preamble / RO) and sending a RA preamble. A fallback may be applied before returning to the first step.

[0018] If a RAR corresponding to its RA preamble transmission is received, the UE sends message 3 (Msg3) in the UL grant received in the RAR. Msg3 includes messages such as RRC connection request, RRC connection reestablishment request, RRC handover confirmation, scheduling request, SI request, etc. It may include the UE identity (i.e., the cell radio network temporary identifier (C-RNTI) or the system architecture evolution (SAE) temporary mobile user identity (S-TMSI) or a random number). After sending Msg3, the UE starts the contention resolution timer. While the contention resolution timer is running, if the UE receives a PDCCH addressed to the C-RNTI included in Msg3, the contention resolution is considered to be successful, the contention resolution timer is stopped, and the RA process is completed. While the contention resolution timer is running, if the UE receives a contention resolution MAC control element (CE) including the UE's contention resolution identity (the first X bits of the common control channel (CCCH) service data unit (SDU) sent in Msg3), the contention resolution is considered to be successful, the contention resolution timer is stopped and the RA process is completed. If the contention resolution timer expires and the UE has not sent the configured number of RA preambles, the UE returns to the first step, i.e., selecting RA resources (preamble / RO) and sending RA preambles. A backoff may be applied before returning to the first step.

[0019] Contention-free RA (CFRA): This is also known as legacy CFRA or 4-step CFRA. The CFRA procedure is used for situations such as handovers where low latency is required, timing advance establishment of Scells, etc. The eNB (or gNB) allocates a dedicated RA preamble to the UE. The UE sends a dedicated RA preamble. The eNB (or gNB) sends a RAR on the PDSCH addressed to the RA-RNTI. The RAR conveys the RA preamble identifier and timing alignment information. The RAR may also include an UL grant. The RAR is transmitted in a RAR window similar to the CBRA procedure. The CFRA is considered to have completed successfully after receiving a RAR including the RAPID of the RA preamble sent by the UE. In case of RA initiation for beam failure recovery, the CFRA is considered to have completed successfully if a PDCCH addressed to the C-RNTI is received in the search space for beam failure recovery. If the RAR window expires and the RA is not completed successfully, and the UE has not sent a configured number of RA preambles (configured by the gNB in ​​the RACH configuration), the UE retransmits the RA preamble.

[0020] For certain events such as with handover and beam failure recovery, if a dedicated preamble is allocated to the UE during the first step of RA, i.e., during RA resource selection for Msg1 transmission, the UE determines whether to send a dedicated preamble or a non-dedicated preamble. Dedicated preambles are usually provided for a subset of SSB / CSI-RS. If no SSB / CSI-RS has a DL reference signal received power (RSRP) above a threshold among the SSB / CSI-RS for which CFRA resources (i.e., dedicated preamble / RO) are provided by the gNB, the UE selects a non-dedicated preamble. Otherwise, the UE selects a dedicated preamble. Therefore, during the RA procedure, one RA attempt can be CFRA and the other RA attempt can be CBRA.

[0021] 2-Step CBRA: In the first step, the UE sends a RA preamble on the PRACH and a payload (i.e., MAC PDU) on the PUSCH. The RA preamble and payload transmission is also referred to as Message A (MSGA). In the second step, after the MSGA transmission, the UE monitors for a response from the network (i.e., gNB) within a configured window. The response is also referred to as Message B (MSGB). If a CCCH SDU is sent in the MSGA payload, the UE performs contention resolution using the contention resolution information in the MSGB. Contention resolution is successful if the contention resolution identifier received in the MSGB matches the first 48 bits of the CCCH SDU sent in the MSGA. If a C-RNTI is sent in the MSGA payload, contention resolution is successful if the UE receives a PDCCH addressed to the C-RNTI. If contention resolution is successful, the RA procedure is considered to be successfully completed. Instead of contention resolution information corresponding to the transmitted MSGA, the MSGB may include backoff information corresponding to the RA preamble sent in the MSGA. If the fallback information is received, the UE sends Msg3 and performs contention resolution using Msg4 as in the CBRA process. If the contention resolution is successful, the RA process is considered to be successfully completed. If the contention resolution fails at the fallback (i.e., when Msg3 is sent), the UE resends MSGA. If the configured window for the UE to monitor the network response after sending MSGA expires and the UE does not receive MSGB including the contention resolution information or fallback information as described above, the UE resends MSGA. If the RA process is not successfully completed even after sending the configured number of MSGAs, the UE falls back to the 4-step RA process, i.e., the UE only sends the RA preamble.

[0022] The MSGA payload may include one or more of a CCCH SDU, a dedicated control channel (DCCH) SDU, a dedicated traffic channel (DTCH) SDU, a buffer status report (BSR) MAC CE, a power headroom report (PHR) MAC CE, SSB information, a C-RNTI MAC CE, or padding. The MSGA may include a UE ID (e.g., a random ID, S-TMSI, C-RNTI, a resume ID, etc.) and the preamble in the first step. The UE ID may be included in the MAC PDU of the MSGA. A UE ID such as a C-RNTI may be carried in a MAC CE, where the MAC CE is included in the MAC PDU. Other UE IDs (e.g., a random ID, S-TMSI, C-RNTI, a resume ID, etc.) may be carried in a CCCH SDU. The UE ID may be one of a random ID, S-TMSI, C-RNTI, a resume ID, an international mobile user identity (IMSI), an idle mode ID, an inactive mode ID, etc. The UE ID may be different in different situations where the UE performs a RA procedure. When the UE performs RA after power-on (before it attaches to the network), the UE ID is a random ID. When the UE performs RA in an idle state after attaching to the network, the UE ID is an S-TMSI. If the UE has an assigned C-RNTI (e.g., in a connected state), the UE ID is a C-RNTI. In the case where the UE is in an inactive state, the UE ID is a summary ID. In addition to the UEID, some additional control information may be sent in the MSGA. The control information may be included in the MAC PDU of the MSGA. The control information may include one or more connection request indications, connection recovery request indications, SI request indications, buffer status indications, beam information (e.g., one or more DL TX beam IDs or one or more SSB IDs), beam failure recovery indication / information, data indicator, cell / base station (BS) / transmit-receive point (TRP) switching indication, connection reconstruction indication, reconfiguration completion or switching completion message, etc.

[0023] 2-step CFRA: In this case, the gNB allocates to the UE a dedicated RA preamble and PUSCH resources for MSGA transmission. The RO for preamble transmission may also be indicated. In the first step, the UE sends the RA preamble on PRACH and payload on PUSCH using the CFRA resources (i.e. dedicated preamble / PUSCH resources / RO). In the second step, after the MSGA transmission, the UE monitors the response from the network (i.e. gNB) within the configured window. If the UE receives a PDCCH addressed to the C-RNTI, the RA procedure is considered to be successfully completed. If the UE receives backoff information corresponding to the preamble it sent, the RA procedure is considered to be successfully completed.

[0024] For certain events such as with handover and beam failure recovery, if dedicated preamble and PUSCH resources are allocated to the UE, then during the first step of RA, i.e., during RA resource selection for MSGA transmission, the UE determines whether to send a dedicated preamble or a non-dedicated preamble. Dedicated preambles are typically provided for a subset of SSB / CSI-RS. If no SSB / CSI-RS has a DL RSRP above a threshold among the SSB / CSI-RS for which CFRA resources (i.e., dedicated preamble / RO / PUSCH resources) are provided by the gNB, the UE selects a non-dedicated preamble. Otherwise, the UE selects a dedicated preamble. Therefore, during the RA procedure, one RA attempt can be a 2-step CFRA, while another RA attempt can be a 2-step CBRA.

[0025] When initiating the RA procedure, the UE first selects a carrier (SUL or NUL). If the carrier used for the RA procedure is explicitly signaled by the gNB, the UE selects the signaled carrier to perform the RA procedure. If the gNB does not explicitly signal the carrier used for the RA procedure; and if the serving cell used for the RA procedure is configured with SUL, and if the RSRP referenced by the DL path loss is less than rsrp-ThresholdSSB-SUL: the UE selects the SUL carrier to perform the RA procedure. Otherwise, the UE selects the NUL carrier to perform the RA procedure. When selecting the UL carrier, the UE determines the UL BWP and DL BWP for the RA procedure (as specified in Section 5.15 of Technical Specification (TS) 38.321). The UE then determines whether to perform a 2-step RA or a 4-step RA for the RA procedure.

[0026] If the RA procedure is initiated by a PDCCH order and if the ra-PreambleIndex explicitly provided by the PDCCH is not 0b000000, the UE selects 4-step RA.

[0027] Otherwise, if 2-step CFRA resources are signaled by the gNB for this RA procedure, the UE selects 2-step RA.

[0028] Otherwise, if 4-step CFRA resources are signaled by the gNB for this RA procedure, the UE selects 4-step RA.

[0029] Otherwise, if the UL BWP selected for this RA procedure is configured with only 2-step RA resources, the UE selects 2-step RA.

[0030] Otherwise, if the UL BWP selected for this RA procedure is configured with only 4-step RA resources, the UE selects 4-step RA.

[0031] Otherwise, if the UL BWP selected for this RA procedure is configured with 2-step and 4-step RA resources and the RSRP referenced by the DL path loss is below the configured threshold, the UE selects 4-step RA. Otherwise, the UE selects 2-step RA.

[0032] In a 5G wireless communication system, a Node B (gNB) or base station in a cell broadcasts an SSB that includes primary and secondary synchronization signals (PSS, SSS) and SI. SI includes common parameters required for communication in a cell. In a 5G wireless communication system (also known as Next Generation Radio or NR), SI is divided into a primary information block (MIB) and multiple secondary information blocks (SIBs), where:

[0033] The MIB is always sent on a broadcast channel (BCH) with a period of 80 milliseconds (ms) and repeated within 80 ms, and it includes parameters required to obtain SIB1 from a cell.

[0034] SIB1 is transmitted on DL-SCH with a periodicity of 160ms and variable transmission repetition. The default transmission repetition period of SIB1 is 20ms, but the actual transmission repetition period depends on the network implementation. The scheduling information in SIB1 includes the mapping between SIBs and SI messages, the periodicity of each SI message, and the SI window length. The scheduling information in SIB1 includes an indicator for each SI message that indicates whether the relevant SI message is being broadcast. If at least one SI message is not broadcast, SIB1 may include RA random access resources (PRACH preamble and PRACH resources) for requesting the gNB to broadcast one or more SI messages.

[0035] SIBs other than SIB1 are carried in system information (SI) messages, which are transmitted on DL-SCH. Only SIBs with the same periodicity can be mapped to the same SI message. Each SI message is transmitted within a periodically occurring time domain window (referred to as an SI window with the same length for all SI messages). Each SI message is associated with an SI window, and the SI windows of different SI messages do not overlap. That is, within an SI window, only the corresponding SI message is sent. Using the indication in SIB1, any SIB except SIB1 can be configured as cell-specific or area-specific. A cell-specific SIB is applicable only to the cell that provides the SIB, while an area-specific SIB is applicable to an area called an SI area, which consists of one or several cells and is identified by systemInformationAreaID.

[0036] The UE obtains SIB1 from the resident cell or serving cell. The UE checks the BroadcastStatus bit in SIB1 to obtain the SI messages that the UE needs to acquire. The gNB signals the SI request configuration for SUL using the si-RequestConfigSUL IE in SIB1. If the si-RequestConfigSUL IE does not exist in SIB1, the UE considers that the SI request configuration for SUL has not been signaled by the gNB. The gNB signals the SI request configuration for NUL using the si-RequestConfig IE in SIB1. If the IE si-RequestConfig does not exist in SIB1, the UE considers that the SI request configuration for NUL has not been signaled by the gNB. If the SI messages that the UE needs to acquire are not broadcast (i.e., the BroadcastStatus bit is set to zero), the UE initiates the transmission of an SI request. The process of this SI request transmission is as follows:

[0037] If the SI request configuration for SUL is signaled by the gNB and the criteria for selecting SUL are met (i.e., RSRP measured from the SSB of the resident cell or serving cell < rsrp-ThresholdSSB-SUL, where rsrp-ThresholdSSB-SUL is signaled by the gNB (e.g., in broadcast signaling such as SIB1)): The UE initiates the transmission of an SI request based on the Msg1-based SI request on SUL. In other words, the UE uses the PRACH preamble and PRACH resources in the SI request configuration for SUL to initiate the RA procedure. The UE sends Msg1 (i.e., the RA preamble) and waits for an acknowledgment of the SI request. Msg1 uses the RA resources (PRACH preamble and PRACH occasion) indicated in the SI request configuration for SUL. Msg1 is transmitted on SUL. If an acknowledgment of the SI request is received, the UE monitors the SI window of the requested SI message during one or more SI cycles of this SI message.

[0038] Otherwise, if the SI request configuration is signaled by the gNB for NUL and the criteria for selecting NUL are met (i.e., NUL is selected if SUL is supported in the resident cell or serving cell and the RSRP measured from the SSB of the resident cell or serving cell is ≥ rsrp-ThresholdSSB-SUL; or NUL is selected if SUL is not supported in the serving cell): The UE initiates the transmission of the SI request based on the Msg1-based SI request. In other words, the UE uses the PRACH preamble and PRACH resources in the SI request configuration of NUL to initiate the RA procedure. The UE sends Msg1 (i.e., the RA preamble) and waits for the confirmation of the SI request. Msg1 uses the RA resources (PRACH preamble and PRACH occasion) indicated in the SI request configuration of NUL. Msg1 is transmitted on NUL. If the confirmation of the SI request is received, the UE monitors the SI window of the requested SI message in one or more SI cycles of this SI message.

[0039] Otherwise, the UE initiates the transmission of the SI request based on the Msg3-based SI request. In other words, the UE initiates the transmission of the RRCSystemInfoRequest message. The UE sends Msg1 (i.e., the RA preamble) and waits for the RAR. Msg1 uses the common RA resources (PRACH preamble and PRACH occasion). The UE sends the RRCSystemInfoRequest message in the UL grant received from the RAR and waits for the confirmation of the SI request (i.e., the RRCSystemInfoRequest message). If the confirmation of the SI request (i.e., the RRCSystemInfoRequest message) is received, the UE monitors the SI window of the requested SI message in one or more SI cycles of this SI message. Note that if SUL is configured, the UL carrier used for Msg1 transmission will be selected by the UE in a similar manner as the UL carrier selected for the Msg1-based SI request. If the RSRP measured from the SSB of the resident cell or serving cell is < rsrp-ThresholdSSB-SUL, where rsrp-ThresholdSSB-SUL is signaled by the gNB (e.g., in broadcast signaling such as SIB1), then SUL is the selected UL carrier. If the RSRP measured from the SSB of the resident cell or serving cell is ≥ rsrp-ThresholdSSB-SUL, where rsrp-ThresholdSSB-SUL is signaled by the gNB (e.g., in broadcast signaling such as SIB1), then NUL is the selected UL carrier.

[0040] 4G and 5G wireless communication systems support vehicle communication services. Vehicle communication services represented by vehicle-to-everything (V2X) services can include vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). In 5G systems, V2X communications are enhanced to support enhanced V2X use cases, which are broadly divided into four use case groups:

[0041] 1) Vehicle platooning enables vehicles to dynamically form a formation to travel together. All vehicles in the formation receive information from the lead vehicle to manage the formation. This information allows vehicles to drive closer than normal in a coordinated manner and travel together in the same direction.

[0042] 2) Extended sensors enable the exchange of raw or processed data collected by local sensors or live video images between vehicles, roadside units, pedestrian devices, and V2X application servers. Vehicles can increase their perception of the environment beyond what their own sensors can detect and have a broader and more holistic view of the local situation. High data rate is one of the key features.

[0043] 3) Advanced driving is capable of semi-autonomous or fully autonomous driving. Each vehicle and / or roadside unit (RSU) shares its own perception data obtained from its local sensors with nearby vehicles, allowing vehicles to synchronize and coordinate their trajectories or maneuvers. Each vehicle also shares its driving intentions with nearby vehicles.

[0044] 4) Remote driving enables remote drivers or V2X applications to operate remote vehicles for passengers who cannot drive themselves or remote vehicles located in hazardous environments. For situations where changes are limited and routes are predictable, such as public transportation, cloud-based driving can be used. High reliability and low latency are the main requirements.

[0045] V2X services may be provided by the PC5 interface and / or the Uu interface. Support for V2X services via the PC5 interface is provided by NR side link (SL) communication or V2X SL communication, which is a communication mode in which UEs can communicate directly with each other through the PC5 interface using NR technology or EUTRA technology, respectively, without passing through any network node, and supports the case where the UE is served by the RAN and the case where the UE is outside the coverage of the RAN. Only UEs licensed for V2X services can perform NR SL or V2X SL communication.

[0046] Figure 1 The NG-RAN architecture supporting the PC5 interface is shown.

[0047] refer to Figure 1, regardless of the RRC state the UE is in, when the UE is within NG-RAN coverage, and when the UE is outside NG-RAN coverage, SL transmission and reception over the PC5 interface are supported. Support for V2X services via the PC5 interface may be provided by NR SL communications and / or V2X SL communications. NR SL communications may be used to support services other than V2X services.

[0048] NR or V2X SL communication can support three types of transmission modes. Unicast transmission is characterized by: supporting at least one PC5-RRC connection between UE pairs; sending and receiving control information and user traffic between UE pairs in SL; supporting SL HARQ feedback; supporting radio link control (RLC) acknowledgement mode (AM); and supporting SL RLM of UE pairs to detect radio link failure (RLF). Multicast transmission is characterized by: sending and receiving user traffic between UEs belonging to a group in SL; supporting SL HARQ feedback. Broadcast transmission is characterized by: sending and receiving user traffic between UEs in SL.

[0049] The access stratum (AS) protocol stack for the control plane in the PC5 interface consists of RRC, Packet Data Convergence Protocol (PDCP), RLC and MAC sublayers, and the physical layer. The AS protocol stack for the user plane in the PC5 interface consists of the Service Data Adaptation Protocol (SDAP), PDCP, RLC and MAC sublayers, and the physical layer. SL Radio Bearers (SLRBs) are divided into two groups: SL Data Radio Bearers (DRBs) for user plane data and SL Signaling Radio Bearers (SRBs) for control plane data. Separate SL SRBs using different SL Control Channels (SCCHs) are configured for PC5-RRC and PC5-S signaling, respectively.

[0050] The MAC sublayer provides the following services and functions on the PC5 interface: radio resource selection; packet filtering; priority handling between UL and SL transmissions for a given UE; SL CSI reporting. Subject to the Logical Channel Prioritization (LCP) restrictions in the MAC, for each unicast, multicast, and broadcast transmission associated with a target, only SL Logical Channels (LCHs) belonging to the same target can be multiplexed into the MAC PDU. The NG-RAN can also control whether the SL LCH can utilize resources allocated to the configured SL grant type 1. For packet filtering, a SL Shared Channel (SL-SCH) MAC header including a source Layer-2 ID part and a target Layer-2 ID part is added to each MAC PDU as specified in subsection 8.x. The LCH Identifier (LCID) included in the MAC subheader uniquely identifies a LCH within the range of the source Layer-2 ID and target Layer-2 ID combination. The following LCHs are used in SL:

[0051] SCCH: SL channel used to send control information from one UE to other UEs;

[0052] SL Traffic Channel (STCH): a SL channel used to send user information from one UE to other UEs; and

[0053] SL Broadcast Control Channel (SBCCH): A SL channel used to broadcast SL SI from one UE to other UEs.

[0054] The following connections exist between LCH and transport channels:

[0055] SCCH can be mapped to SL-SCH;

[0056] STCH may be mapped to SL-SCH; and

[0057] SBCCH can be mapped to SL-BCH.

[0058] The RRC sublayer provides the following services and functions on the PC5 interface:

[0059] Transmitting PC5-RRC messages between UE pairs;

[0060] Maintaining and releasing the PC5-RRC connection between two UEs; and

[0061] PC5-Detection of SL RLF of RRC connection.

[0062] A PC5-RRC connection is a logical connection between two UEs of a pair of source layer-2 ID and target layer-2 ID, which is considered to be established after the corresponding PC5 unicast link is established as specified in TS23.287. There is a one-to-one correspondence between PC5-RRC connections and PC5 unicast links. A UE may have multiple PC5-RRC connections with one or more UEs with different source layer-2 ID and target layer-2 ID pairs. The UE uses separate PC5-RRC procedures and messages to transmit UE capabilities and SL configuration including SLRB configuration to peer UEs. UE pairs may exchange their own UE capabilities and SL configuration using separate bidirectional procedures in both SL directions. If there is no interest in SL transmission, if a SL RLF on the PC5-RRC connection is declared, or if the layer-2 link release procedure is completed as specified in TS23.287, the UE releases the PC5-RRC connection.

[0063] For resource allocation in SL, UE can operate in two modes:

[0064] The characteristics of scheduling resource allocation are: UE needs to be in RRC_CONNECTED to transmit data; NG-RAN schedules transmission resources.

[0065] The characteristics of UE autonomous resource selection are: no matter which RRC state the UE is in, the UE can transmit data within the NG-RAN coverage area, as well as transmit data outside the NG-RAN coverage area; the UE automatically selects transmission resources from the resource pool.

[0066] For NR SL communication, the UE performs SL transmission on a single carrier only.

[0067] Scheduling resource allocation: For NR SL communication, NG-RAN can dynamically allocate resources to UEs via SL-RNTI on PDCCH. In addition, NG-RAN can allocate SL resources to UEs using two types of configured SL grants:

[0068] For Type 1, RRC directly provides the configured SL grant for NR SL communication, and

[0069] For Type 2, RRC provides the periodicity of the configured SL grants, while PDCCH can signal and activate the configured SL grant, or deactivate it. PDCCH provides the actual grant (i.e. resources) to be used. For NR SL communication, PDCCH is addressed to SL-Configuration Scheduling (CS)-RNTI and for V2X SL communication, SL Semi-Persistent Scheduling V2X (V)-RNTI.

[0070] For UEs performing NR SL communications, more than one configured SL grant may be activated at a time on a carrier configured for SL transmission. When beam failure or physical layer issues occur on NR Uu, the UE may continue to use the configured SL grant type 1. During handover, any type of configured SL grant may be provided to the UE via the handover command. If provided, the UE activates the configured SL grant type 1 upon receipt of the handover command. The UE may send a SL BSR to support scheduler operations in NG-RAN. SL BSR refers to the data buffered per target for a group of LCHs (LCG) in the UE. SL BSR is reported using 8 LCGs. Two formats, SL BSR and truncated SL BSR, are used.

[0071] UE autonomous resource allocation: When the UE is within the NG-RAN coverage, the UE automatically selects the SL grant from the resource pool provided by broadcast SI or dedicated signaling, or when the UE is outside the NG-RAN coverage, the SL grant is automatically selected through pre-configuration.

[0072] For NR SL communications, a resource pool may be provided for a given validity area, at least when the resource pool is provided by SIB (e.g., reusing the validity area of ​​NR SIB), so that the UE does not need to acquire a new resource pool when moving within the validity area. Reuse the NR SIB validity mechanism so that the validity area of ​​the SL resource pool is configured via the broadcasted SI. Allow UEs to temporarily use UE autonomous resource selection for SL transmission using random selection based on the configuration of a special transmission resource pool.

[0073] For V2X SL transmission, during handover, a transmission resource pool configuration including a special transmission resource pool of the target cell may be signaled in the handover command to reduce transmission interruption. In this way, the UE may use the V2X SL transmission resource pool of the target cell before handover is completed, as long as synchronization is performed with the target cell if the eNB is configured as a synchronization source, or synchronization is performed with the Global Navigation Satellite System (GNSS) if the GNSS is configured as a synchronization source. If the special transmission resource pool is included in the handover command, the UE uses resources randomly selected from the special transmission resource pool starting from receipt of the handover command. If the UE is configured with scheduled resource allocation in the handover command, the UE continues to use the special transmission resource pool while the timer associated with the handover is running. If the UE is configured with autonomous resource selection in the target cell, the UE continues to use the special transmission resource pool until sensing results on the transmission resource pool are available for autonomous resource selection. For special cases (e.g., during RLF, during transition from RRC_IDLE to RRC_CONNECTED, or during change of dedicated V2X SL resource pool within a cell), the UE may select resources in a special resource pool provided in SIB21 of the serving cell or in dedicated signaling based on random selection and use them temporarily. During cell reselection, an RRC_IDLE UE may use resources randomly selected from a special transmission resource pool of the reselected cell until sensing results on the transmission resource pool are available for autonomous resource selection.

[0074] Issue: For NR V2X communications, Configured Grant (CG) Type 1 grants are supported. Its use is limited to SL LCHs indicated by the gNB. The CG Type 1 grant is activated immediately upon receipt of a handover command. In case the handover command includes a CG Type 1 grant for the target cell, interruption will be avoided for SL LCHs for which the use of CG Type 1 is allowed. For other LCHs, interruption will still occur because those SL LCHs may be scheduled in a dynamic grant and the dynamic grant is received only after the handover is completed. This interruption can be avoided by configuring a special TX resource pool for the other LCHs. However, this is not possible because simultaneous configuration of scheduled resource allocation and autonomous resource allocation is not supported.

[0075] The above information is presented as background information only and is provided to assist in understanding 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 respect to the present disclosure. Summary of the invention

[0076] Technical issues

[0077] In case the handover command includes a CG type 1 grant for the target cell, the interruption will be avoided for the SLLCHs that are allowed to use CG type 1. For other LCHs, the interruption will still occur because those SL LCHs may be scheduled in a dynamic grant and the dynamic grant is received only after the handover is completed.

[0078] Due to logical channel prioritization, SL CQI / RI reports may not send MACCE in available SL resources. It is also possible that SL transmissions in available SL resources may overlap with uplink (UL) and may be dropped due to priority rules.

[0079] From RA, the gNB cannot identify that the UE requires SL resources.

[0080] Since the SL MAC CE is not considered for target selection, the target is incorrectly selected and the transmission of the SL MAC CE may be delayed.

[0081] Technical Solution

[0082] An aspect of the present disclosure is to solve at least the above problems and / or disadvantages and to provide at least the advantages described below. Therefore, one aspect of the present disclosure is to provide a communication method and system for aggregating a fifth generation (5G) communication system to support a higher data rate than a fourth generation (4G) system.

[0083] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments.

[0084] According to one aspect of the present disclosure, a method performed by a terminal in a wireless communication system is provided. The method includes identifying that a side link channel state information (SL-CSI) report is triggered; identifying whether SL resources are allocated for new transmission; performing logical channel priority setting on the SL resources; and determining whether to trigger a scheduling request for the SL-CSI report based on the result of the logical channel priority setting.

[0085] According to another aspect of the present disclosure, a terminal in a wireless communication system is provided. The terminal includes a transceiver and a controller connected to the transceiver. The controller is configured to identify that an SL-CSI report is triggered, identify whether an SL resource is allocated for a new transmission, perform logical channel priority setting on the SL resource, and determine whether to trigger a scheduling request for an SL-CSI report based on a result of the logical channel priority setting.

[0086] Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure.

[0087] Before proceeding to the following detailed description, it may be helpful to set forth definitions of certain words and phrases used in this patent document: the terms "include" and "comprising" and their derivatives mean including but not limited to; the term "or" is inclusive, referring to and / or; the phrases "associated with" and "associated with" and their derivatives may mean including, included, interconnected with, containing, contained within, connected to or connected with, connected to or connected with, communicable with, cooperating with, interleaved, juxtaposed, adjacent, bound to or bound with, having, having the property of, etc.; and the term "controller" means any device, system, or part thereof that controls at least one operation, such device may be implemented in hardware, firmware, or software, or a combination of at least two of the foregoing. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether local or remote.

[0088] In addition, the various functions described below can be implemented or supported by one or more computer programs, each of which is formed by a computer-readable program code and is contained in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, instances, related data, or parts thereof suitable for implementation in appropriate computer-readable program codes. 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 that can be accessed by a computer, such as a read-only memory (ROM), a random access memory (RAM), a hard drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. "Non-transitory" computer-readable media excludes wired, wireless, optical, or other communication links that transmit temporary electrical or other signals. A non-transitory computer-readable medium includes a medium that can permanently store data, and a medium that can store data and then rewrite data, such as a rewritable optical disc or an erasable storage device.

[0089] 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.

[0090] Beneficial Effects

[0091] The conditions for triggering SR for SL CQI / RI reporting are enhanced.

[0092] In case SR configuration is not configured for SL CQI / RI reporting, some mechanism is provided to request SL resources for SL CQI / RI reporting. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0094] Figure 1 It shows that the next generation radio access network (NG-RAN) architecture supports the PC5 interface;

[0095] Figure 2 The operation of a user equipment (UE) for handling a configured grant (CG) type 1 grant during handover according to an embodiment of method 1 of the present disclosure is shown;

[0096] Figure 3 The operation of a UE for processing a CG type 1 grant during handover according to another embodiment of method 1 of the present disclosure is shown;

[0097] Figure 4 The operation of a UE for handling a CG type 1 grant during handover according to an embodiment of method 2 of the present disclosure is shown;

[0098] Figure 5 The operation of a UE for handling a CG type 1 grant during handover according to an embodiment of method 3 of the present disclosure is shown;

[0099] Figure 6 The operation of a UE for processing a CG type 1 grant during handover according to another embodiment of method 3 of the present disclosure is shown;

[0100] Figure 7 The operation of a UE for sidelink (SL) channel quality indicator (CQI) / rank indicator (RI) reporting for New Radio (NR) SL communication according to an embodiment of method 1 based on the present disclosure is shown;

[0101] Figure 8The operation of a UE for SL CQI / RI reporting for NR SL communication according to an embodiment of Method 2 based on the present disclosure is shown;

[0102] Fig. 9 The operation of a UE for SL CQI / RI reporting for NR SL communication according to an embodiment of method 3 based on the present disclosure is shown;

[0103] Fig.10 The operation of a UE for SL CQI / RI reporting for NR SL communication according to an embodiment of method 4 based on the present disclosure is shown;

[0104] Fig.11 A medium access control (MAC) control element (CE) format of a SL buffer status report (BSR) according to an embodiment of the present disclosure is shown;

[0105] Fig.12 is a block diagram of a terminal according to an embodiment of the present disclosure; and

[0106] Fig.13 is a block diagram of a base station according to an embodiment of the present disclosure.

[0107] Throughout the drawings, like reference numerals will be understood to refer to like parts, components, and structures. DETAILED DESCRIPTION

[0108] Discussed below Figure 1-11 The various embodiments used to describe the principles of the present disclosure in this patent document are exemplary only and should not be interpreted in any way as limiting the scope of the present disclosure. Those skilled in the art will appreciate that the principles of the present disclosure can be implemented in any suitably arranged system or device.

[0109] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in understanding, but these are considered to be exemplary only. Therefore, it will be appreciated by those of ordinary skill in the art that various changes and modifications may be made to the various embodiments described herein without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and structures may be omitted for clarity and brevity.

[0110] The terms and words used in the following description and claims are not limited to the bibliographic meanings, but are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Therefore, it should be clear to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustrative purposes only and not for limiting the disclosure defined by the attached claims and their equivalents.

[0111] 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.

[0112] The term "substantially" means that the features, parameters or values ​​described need not be achieved precisely, but deviations or changes including such factors as tolerances, measurement errors, measurement precision limitations and other factors known to those skilled in the art may occur in an amount that does not eliminate the effect that the feature is intended to provide.

[0113] Those skilled in the art know that the blocks of the flowchart (or sequence diagram) and the combination of the flowchart can be represented and executed by computer program instructions. These computer program instructions can be loaded onto a processor of a general-purpose computer, a special-purpose computer, or a programmable data processing device. When the loaded program instructions are executed by the processor, they create a device for performing the functions described in the flowchart. Because the computer program instructions can be stored in a computer-readable memory that can be used for a special-purpose computer or a programmable data processing device, it is also possible to create an article that performs the functions described in the flowchart. Because the computer program instructions can be loaded onto a computer or a programmable data processing device, when executed as a process, they can perform the operations of the functions described in the flowchart.

[0114] The block of flow chart may correspond to a module, segment or code containing one or more executable instructions that realize one or more logical functions, or may correspond to a part thereof. In some cases, the functions described by the block may be performed sequentially in a sequence different from the listed order. For example, two blocks listed in sequence may be performed simultaneously or in reverse order.

[0115] In this specification, the words "unit", "module", etc. may refer to software components or hardware components, such as field programmable gate arrays (FPGAs) or application specific integrated circuits (ASICs) that can perform functions or operations. However, "units", etc. are not limited to hardware or software. Units, etc. may be configured to be stored in addressable storage media or drive one or more processors. Units, etc. may also refer to software components, object-oriented software components, class components, task components, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, or variables. The functions provided by components and units may be combinations of smaller components and units, and may be combined with other components and units to form larger components and units. Components and units may be configured to drive one or more processors in a device or a secure multimedia card.

[0116] Prior to the detailed description, terms or definitions necessary for understanding the present disclosure are described However, these terms should be interpreted in a non-limiting manner.

[0117] A base station (BS) is an entity that communicates with a user equipment (UE) and may be referred to as a BS, a base transceiver station (BTS), a node B (NB), an evolved NB (eNB), an access point (AP), a fifth generation (5G) NB (5GNB), or a next generation NB (gNB).

[0118] The UE is an entity communicating with the BS and may be referred to as a UE, a device, a mobile station (MS), a mobile equipment (ME), or a terminal.

[0119] Handling of Configured Grant (CG) Type 1 Grants during Switchover

[0120] Method 1:

[0121] Figure 2 The operation of a UE for handling a CG type 1 license during handover according to an embodiment of method 1 based on the present disclosure is shown.

[0122] The UE is in a radio resource control (RRC) connected state and performs NR side link (SL) communication using resource configuration (scheduled resource allocation or autonomous resource allocation) provided by a serving cell (in one embodiment, the serving cell can be a primary cell (PCell), or in another embodiment, the serving cell can be a specific cell (SpCell)).

[0123] Reference Figure 2 , in the RRC connected state, at operation 210, the UE receives a handover or RRC reconfiguration message (e.g., a handover command) including reconfigurationWithSync from the network (i.e., the BS or the source PCell or the source SpCell). The reconfiguration message configures the resource allocation (also referred to as mode 1) for scheduling in the target cell (in one embodiment, the target cell may be a PCell, or in another embodiment, the target cell may be a SpCell). Specifically, the reconfiguration message includes a CG type 1 SL license configuration in the target cell for new radio (NR) SL communications. The reconfiguration message does not include a special resource pool for transmission. The reconfiguration message also indicates one or more SL logical channels (LCHs) that are allowed to use the CG type 1 SL license.

[0124] In one method of the present disclosure, upon receiving a handover command or RRC reconfiguration message including reconfigurationWithSync: at operation 220, the UE starts a timer T 304, and at operation 230, if included in the RRC reconfiguration message, activates a CG type 1 SL grant for NR SL communication. Once synchronization is performed with a gNB when the gNB is configured as a synchronization source, or synchronization is performed with a global navigation satellite system (GNSS) when the GNSS is configured as a synchronization source, or synchronization is performed with a UE sending a synchronization signal when the UE is configured as a synchronization source, the UE starts using a CG type 1 SL grant for NR SL communication. At operation 240, if necessary, the UE synchronizes with the downlink (DL) of the target SpCell and acquires the MIB of the target SpCell. At operation 250, the UE initiates a random access (RA) procedure to the target SpCell. At operation 260, once the RA procedure is completed, the UE stops the timer T 304. At operation 270, the UE applies a CG type 1 SL grant to a SL LCH that allows the use of CG type 1.

[0125] In this method, before the handover is completed (i.e. when timer T 304 is running), the UE uses CG type 1 SL grant for all SL LCHs. This means that before the handover is completed, the UE does not follow the LCH restrictions indicated by the gNB regarding CG type 1.

[0126] After handover is completed, the CG Type 1 SL grant is only used for the SL LCHs indicated by the gNB. This means that after handover is completed, the UE follows the LCH restrictions indicated by the gNB regarding CG Type 1. The reconfiguration message indicates one or more SL LCHs that are allowed to use the CG Type 1 SL grant.

[0127] For example, assume that the UE has 4 SL LCHs (e.g., LCH 1, LCH 2, LCH 3, and LCH 4) established for NR SL communication. The network configures a CG type 1 SL license in the handover command. As per the configuration received from the network, the CG type 1 SL license is allowed to be used for LCH 1 and LCH 2. Upon receiving the handover command, the UE activates the CG type 1 SL license. Before the handover is completed, the UE uses the CG type 1 SL license for SL LCH 1-4. Upon completion of the handover, the UE uses the CG type 1 SL license for SL LCH 1-2.

[0128] Figure 3 The operation of a UE for processing a CG type 1 license during switching according to another embodiment of method 1 based on the present disclosure is shown.

[0129] Reference Figure 3At operation 310, the UE receives a handover command. The handover command includes a CG type 1 SL license for NR SL communication. At operation 320, the UE starts a timer T 304. At operation 330, the UE activates the CG type 1 SL license for NR SL communication.

[0130] In another embodiment of the disclosed method, the network may indicate whether the UE is allowed to use CG type 1 for all SLLCHs or only for the indicated SL LCHs during handover. The presence of a new parameter (UseCGType1forAllSLLCHs) in the RRC reconfiguration message may indicate that the UE is able to use CG type 1 for all SL LCHs during handover. The new parameter (UseCGType1forAllSLLCHs) in the RRC reconfiguration message may be set to TRUE to indicate that the UE is able to use CG type 1 for all SL LCHs during handover.

[0131] At operation 340, the UE identifies whether an indication to use CG type 1 for all SL LCHs is received. At operation 350, if the indication is received, the UE applies a CG type 1 SL license to all SL LCHs. Otherwise, at operation 360, the UE applies a CG type 1 SL license to SL LCHs that are allowed to use CG type 1. At operation 370, if necessary, the UE synchronizes to the DL of the target SpCell and obtains the MIB of the target SpCell. At operation 380, the UE initiates a RA procedure to the target SpCell. At operation 390, once the RA procedure is completed, the UE stops timer T 304. At operation 400, the UE applies a CG type 1 SL license to SL LCHs that are allowed to use CG type 1.

[0132] Method 2:

[0133] Figure 4 The operation of a UE for processing a CG type 1 license during switching according to an embodiment of method 2 based on the present disclosure is shown.

[0134] The UE is in an RRC connected state and performs NR SL communication using resource configuration (scheduled resource allocation or autonomous resource allocation) provided by a serving cell (in one embodiment, the serving cell may be a PCell, or in another embodiment, the serving cell may be a SpCell).

[0135] Reference Figure 4, in the RRC connected state, at operation 410, the UE receives an RRC reconfiguration message (e.g., a handover command) including reconfigurationWithSync from the network (i.e., the BS or the source PCell or the source SpCell). The reconfiguration message configures the resource allocation (also referred to as mode 1) for scheduling in the target cell (in one embodiment, the target cell may be a PCell, or in another embodiment, the target cell may be a SpCell). Specifically, the reconfiguration message includes a CG type 1 SL grant configuration in the target cell for NR SL communication. The reconfiguration message may or may not configure a special resource pool for transmission. The reconfiguration message also indicates one or more SL LCHs that are allowed to use the CG type 1 SL grant.

[0136] In one method of the present disclosure, upon receiving a handover command or an RRC reconfiguration message including reconfigurationWithSync: at operation 420, the UE starts a timer T304, and at operation 430, identifies whether a special resource pool for transmission is configured.

[0137] If a special resource pool for transmission is configured: Activate the CG Type 1 SL grant after handover is completed. The UE uses the CG Type 1 SL grant after handover is completed. Before handover is completed, the UE uses the special resource pool for NR SL transmission.

[0138] The UE starts using the special resource pool 440 for NR SL transmission. At operation 442, the UE synchronizes to the DL of the target SpCell and obtains the MIB of the target SpCell if necessary. At operation 444, the UE initiates a RA procedure to the target SpCell. At operation 446, upon completion of the RA procedure, the UE stops timer T 304. At operation 448, the UE stops using the special resource pool for NR SL transmission. At operation 450, the UE activates the CG type 1 SL license and applies the CG type 1 SL license for the SL LCHs that are allowed to use the CG type 1 SL license.

[0139] If the special resource pool for transmission is not configured: If the CG Type 1 SL grant is included in the RRC reconfiguration message, the UE activates the CG Type 1 SL grant. The UE starts using the CG Type 1 SL grant for NR SL communication upon synchronization with the gNB if the gNB is configured as a synchronization source, with the GNSS if the GNSS is configured as a synchronization source, or with the UE sending a synchronization signal if the UE is configured as a synchronization source.

[0140] The UE uses the CG Type 1 SL grant only for SL LCHs for which the use of the CG Type 1 SL grant is allowed. The CG Type 1 SL grant is only used for SL LCHs indicated by the gNB. The reconfiguration message indicates one or more SLLCHs for which the use of the CG Type 1 SL grant is allowed.

[0141] At operation 460, the UE activates the CG type 1 SL license and applies the CG type 1 SL license for the SL LCHs that are allowed to use the CG type 1 SL license. At operation 462, if necessary, the UE synchronizes to the DL of the target SpCell and obtains the MIB of the target SpCell. At operation 464, the UE initiates the RA procedure to the target SpCell. At operation 466, once the RA procedure is completed, the UE stops the timer T 304. At operation 468, the UE continues to use the CG type 1 SL license for the SL LCHs that are allowed to use the CG type 1 SL license.

[0142] Method 3:

[0143] Figure 5 The operation of a UE for processing a CG Type 1 license during handover according to an embodiment of Method 3 based on the present disclosure is shown.

[0144] Reference Figure 5 At operation 510, the UE receives a handover command. The handover command includes a CG type 1 SL grant for NR SL communication. At operation 520, the UE starts a timer T 304.

[0145] In one method of the present disclosure, upon receiving a handover command or an RRC reconfiguration message including reconfigurationWithSync: at operation 530, the UE identifies whether a special resource pool for transmission is configured.

[0146] If a special resource pool for transmission is configured: Activate the CG Type 1 SL grant after handover is completed. The UE uses the CG Type 1 SL grant after handover is completed. Before handover is completed, the UE uses the special resource pool for NR SL transmission.

[0147] The UE starts using the special resource pool for NR SL transmission 540. If necessary, at operation 542, the UE synchronizes to the DL of the target SpCell and obtains the MIB of the target SpCell. At operation 544, the UE initiates a RA procedure to the target SpCell. At operation 546, upon completion of the RA procedure, the UE stops timer T 304. At operation 548, the UE stops using the special resource pool for NR SL transmission. At operation 550, the UE activates the CG type 1 SL license and applies the CG type 1 SL license for the SL LCHs that are allowed to use the CG type 1 SL license.

[0148] If the special resource pool for transmission is not configured: If the CG Type 1 SL grant is included in the RRC reconfiguration message, the UE activates the CG Type 1 SL grant. Upon synchronization with the gNB if the gNB is configured as a synchronization source, or with the GNSS if the GNSS is configured as a synchronization source, or with the UE sending the synchronization signal if the UE is configured as a synchronization source, the UE starts NR SL communication using the CG Type 1 SL grant.

[0149] Before the handover is completed (i.e. when timer T 304 is running), the UE uses CG type 1 SL license for all SL LCHs. This means that before the handover is completed, the UE does not follow the LCH restrictions on CG type 1 indicated by the gNB. When the handover is completed, the CG type 1 SL license is only used for the SL LCH indicated by the gNB. This means that after the handover is completed, the UE follows the LCH restrictions on CG type 1 indicated by the gNB. The reconfiguration message indicates one or more SL LCHs that are allowed to use the CG type 1 SL license. For example, assume that the UE has 4 SL LCHs (e.g., LCH 1, LCH 2, LCH 3, and LCH 4) established for NR SL communication. The network configures the CG type 1 SL license in the handover command. According to the configuration received from the network, the CG type 1 SL license is allowed to be used for LCH 1 and LCH 2. Upon receiving the handover command, the UE activates the CG type 1 SL license. Before the handover is completed, the UE uses the CG type 1 SL license for SL LCH 1-4. When the handover is completed, the UE uses the CG type 1 SL license for SL LCH 1-2.

[0150] At operation 560, the UE activates the CG type 1 SL license and applies the CG type 1 SL license to all SL LCHs. At operation 562, the UE synchronizes to the DL of the target SpCell if necessary and acquires the MIB of the target SpCell. At operation 564, the UE initiates an RA procedure to the target SpCell. At operation 566, upon completion of the RA procedure, the UE stops the timer T 304. At operation 568, the UE applies the CG type 1 SL license to the SL LCHs that are allowed to use the CG type 1 SL license.

[0151] Figure 6 The operation of a UE for processing a CG type 1 license during switching according to another embodiment of method 3 based on the present disclosure is shown.

[0152] Reference Figure 6, at operation 610, the UE receives a handover command. The handover command includes a CG type 1 SL grant for NR SL communication. At operation 620, the UE starts timer T 304. Upon receiving an RRC reconfiguration message or a handover command including reconfigurationWithSync: At operation 630, the UE identifies whether a special resource pool for transmission is configured.

[0153] If a special resource pool for transmission is configured, the UE starts using the special resource pool 640 for NR SL transmission. At operation 642, if necessary, the UE synchronizes to the DL of the target SpCell and obtains the MIB of the target SpCell. At operation 644, the UE initiates a RA procedure to the target SpCell. At operation 646, once the RA procedure is completed, the UE stops timer T 304. At operation 648, the UE stops using the special resource pool for NR SL transmission. At operation 650, the UE activates the CG type 1 SL license and applies the CG type 1 SL license for the SL LCHs that are allowed to use the CG type 1 SL license.

[0154] If a special resource pool for transmission is not configured, then at operation 660, the UE activates a CG type 1SL license for NRSL communication.

[0155] In another embodiment of the disclosed method, the network may indicate whether the UE is allowed to use CG type 1 for all SLLCHs or only for the indicated SL LCHs during handover. The presence of a new parameter (UseCGType1forAllSLLCHs) in the RRC reconfiguration message may indicate that the UE is able to use CG type 1 for all SL LCHs during handover. The new parameter (UseCGType1forAllSLLCHs) in the RRC reconfiguration message may be set to TRUE to indicate that the UE may use CG type 1 for all SL LCHs during handover.

[0156] At operation 662, the UE identifies whether an indication to use CG type 1 for all SL LCHs is received. If the indication is received, at operation 664, the UE applies a CG type 1 SL license to all SL LCHs. Otherwise, at operation 666, the UE applies a CG type 1 SL license to SL LCHs that are allowed to use CG type 1. At operation 668, if necessary, the UE synchronizes to the DL of the target SpCell and obtains the MIB of the target SpCell. At operation 670, the UE initiates a RA procedure to the target SpCell. At operation 390, once the RA procedure is completed, the UE stops timer T 304. At operation 400, the UE applies a CG type 1 SL license to SL LCHs that are allowed to use CG type 1.

[0157] SL Channel Quality Indicator (CQI) / Rank Indicator (RI) reporting for NR SL communications

[0158] In case of NR SL unicast communication, for SL CQI / RI reporting, a SL CQI / RI reporting medium access control (MAC) control element (CE) is sent from the receiving (RX) UE to the transmitting (TX) UE. The physical layer (L1) in the RX UE instructs the MAC layer to send the SL CQI / RI report. The MAC layer in the RX UE initiates the transmission of the SL CQI / RI reporting MAC CE. If the RX UE is configured with scheduled resource allocation (i.e., Mode 1) and there are no available configured SL resources: The MAC layer in the RX UE triggers a scheduling request (SR), where the SR configuration for the SL CQI / RI reporting MAC CE is configured by the network via RRC signaling. Since this SR is dedicated to the SL MAC CE, upon receiving the SR, the network (i.e., gNB) schedules the SL grant to the RX UE. The RX UE sends the SL CQI / RI reporting MAC CE in the SL grant. If the RX UE is configured with scheduled resource allocation (i.e., Mode 1) and if there are available configured SL resources, the UE does not trigger the SR.

[0159] Question 1: If the UE is configured with available SL resources, the UE does not trigger an SR. It is assumed that the SL CQI / RI report MAC CE can be sent to the TX UE using the configured SL resources. However, due to the logical channel priority setting (LCP), the SL CQI / RI report MAC CE may not be sent in the available SL resources. Therefore, the conditions for triggering the SR for SL CQI / RI reporting need to be enhanced. It is also possible that the SL transmission in the available SL resources may overlap with the uplink (UL), and the SL transmission may be abandoned due to the priority rules defined in the Technical Specification (TS) 38.321 for SL and UL priorities.

[0160] Method 1:

[0161] Figure 7 The operation of a UE for SL CQI / RI reporting for NR SL communication according to an embodiment of method 1 based on the present disclosure is shown.

[0162] In one method of the present disclosure, it is proposed that if scheduled resource allocation is configured for NR SL communication, and SL CQI / RI reporting is triggered, and SR configuration for SL CQI / RI reporting is configured by the network via RRC signaling, the UE determines whether to trigger SR for SL CQI / RI reporting as follows.

[0163] refer to Figure 7 , triggering a SL CQI / RI report MAC CE at operation 710. At operation 720, the UE identifies whether SL shared channel (SL-SCH) resources are available for new transmission. If SL-SCH resources are available for new transmission, at operation 730, the UE identifies whether the SL-SCH resources can accommodate a SL CQI / RI report MAC CE plus a sub-header (as a result of LCP) (LCP is defined in TS 38.321 for NR SL communication). If the SL-SCH resources can accommodate the SL CQI / RI report MAC CE plus its sub-header: at operation 740, the UE does not trigger an SR for SL CQI / RI reporting. Otherwise, at operation 750, the UE triggers an SR for SL CQI / RI reporting.

[0164] (Optional) If SL-SCH resources are available for new transmission within the timer interval T and this SL-SCH resource can accommodate the SL CQI / RI reporting MAC CE plus subheader (as a result of LCP) (LCP is defined in TS 38.321 for NRSL communications): UE does not trigger SR for SL CQI / RI reporting. Otherwise, UE triggers SR for SL CQI / RI reporting.

[0165] The time interval T is configurable via RRC signaling and starts when SL CQI / RI reporting is triggered.

[0166] Method 2:

[0167] Figure 8 The operation of a UE for SL CQI / RI reporting for NR SL communication according to an embodiment of Method 2 based on the present disclosure is shown.

[0168] In another method of the present disclosure, it is proposed that if scheduled resource allocation is configured for NR SL communication, and SL CQI / RI reporting is triggered, and SR configuration for SL CQI / RI reporting is configured by the network via RRC signaling, the UE determines whether to trigger SR for SL CQI / RI reporting as follows.

[0169] refer to Figure 8, triggering a SL CQI / RI report MAC CE at operation 810. At operation 820, the UE identifies whether SL-SCH resources are available for new transmission. If SL-SCH resources are available for new transmission, at operation 830, the UE identifies whether the SL-SCH resources can accommodate the SL CQI / RI report MAC CE plus a sub-header (as a result of LCP) (LCP is defined in TS 38.321 for NR SL communication). If the SL-SCH resources can accommodate the SL CQI / RI report MAC CE plus its sub-header, at operation 840, the UE identifies whether the available SL SCH resources overlap with UL SCH resources. If the available SL SCH resources overlap with UL SCH resources, at operation 850, the UE identifies whether SL transmission takes precedence over UL. If the available SL-SCH resource does not overlap with the UL SCH resource, or the SL transmission takes precedence over the UL, i.e. due to the priority between SL and UL (the priority between SL and UL is defined in TS 38.321 for NR SL communication), the SL transmission in the available SL-SCH resource is not abandoned: at operation 860, the UE does not trigger the SR for SL CQI / RI reporting. Otherwise, at operation 870, the UE triggers the SR for SL CQI / RI reporting.

[0170] (Optional) If SL-SCH resources are available for new transmission within timer interval T and SL-SCH resources can accommodate SL CQI / RI reporting MAC CE plus sub-header (as a result of LCP) (LCP is defined in TS 38.321 for NR SL communication) and SL transmission in this available SL-SCH resource is not dropped due to priority between SL and UL (Priority between SL and UL is defined in TS 38.321 for NR SL communication): UE does not trigger SR for SL CQI / RI reporting. Otherwise, UE triggers SR for SL CQI / RI reporting.

[0171] The time interval T is configurable via RRC signaling and starts when SL CQI / RI reporting is triggered.

[0172] Method 3:

[0173] Fig. 9 The operation of a UE for SL CQI / RI reporting for NR SL communication according to an embodiment of Method 3 based on the present disclosure is shown.

[0174] In another method of the present disclosure, it is proposed that if scheduled resource allocation is configured for NR SL communication, and SL CQI / RI reporting is triggered, and SR configuration for SL CQI / RI reporting is configured by the network via RRC signaling, the UE determines whether to trigger SR for SL CQI / RI reporting as follows.

[0175] refer to Fig. 9 , at operation 910, a SL CQI / RI report MAC CE is triggered. At operation 920, the UE identifies whether SL-SCH resources are available for new transmission. If SL-SCH resources are available for new transmission, at operation 930, the UE identifies whether the SL-SCH resources can accommodate the SL CQI / RI report MAC CE plus a sub-header (as a result of LCP) (LCP is defined in TS 38.321 for NR SL communication). If the SL-SCH resources can accommodate the SL CQI / RI report MAC CE plus its sub-header, at operation 940, the UE identifies whether the available SL-SCH resources overlap in time with the UL SCH resources. If the available SL-SCH resources do not overlap with the UL-SCH resources: at operation 950, the UE does not trigger an SR for SL CQI / RI reporting. Otherwise, at operation 960, the UE triggers an SR for SL CQI / RI reporting.

[0176] (Optional) If SL-SCH resources are available for new transmission within timer interval T and SL-SCH resources can accommodate SL CQI / RI reporting MAC CE plus subheader (as a result of LCP) (LCP is defined in TS 38.321 for NR SL communication) and available SL-SCH resources do not overlap in time with UL-SCH resources: UE does not trigger SR for SL CQI / RI reporting. Otherwise, UE triggers SR for SL CQI / RI reporting.

[0177] The time interval T is configurable via RRC signaling and starts when SL CQI / RI reporting is triggered.

[0178] Method 4:

[0179] Fig.10 The operation of a UE for SL CQI / RI reporting for NR SL communication according to an embodiment of method 4 based on the present disclosure is shown.

[0180] In another method of the present disclosure, it is proposed that if scheduled resource allocation is configured for NR SL communication, and SL CQI / RI reporting is triggered, and SR configuration for SL CQI / RI reporting is configured by the network via RRC signaling, the UE determines whether to trigger SR for SL CQI / RI reporting as follows.

[0181] refer to Fig.10 , triggering SL CQI / RI reporting MAC CE at operation 1010. At operation 1020, the UE identifies whether SL-SCH resources are available for new transmission. If SL-SCH resources are available for new transmission, at operation 1030, the UE identifies whether the available SL-SCH resources overlap with UL SCH resources in time. If the available SL-SCH resources do not overlap with UL-SCH resources: at operation 1040, the UE does not trigger SR for SL CQI / RI reporting. Otherwise, at operation 1050, the UE triggers SR for SL CQI / RI reporting.

[0182] (Optional) If SL-SCH resources are available for new transmissions within time interval T, and the available SL-SCH resources do not overlap with UL-SCH resources in time: the UE does not trigger SR for SL CQI / RI reporting. Otherwise, the UE triggers SR for SL CQI / RI reporting.

[0183] The time interval T is configurable via RRC signaling and starts when SL CQI / RI reporting is triggered.

[0184] In the above method (1-4), when the SL CQI / RI report is triggered for a unicast connection, the MAC layer starts a timer. The value of the timer is configured by the network (e.g., gNB) via RRC signaling, that is, the RRC configures the value of the timer to control the SL-CSI reporting process, where the value of the timer is maintained for each PC5-RRC connection. This timer is used for the SL-CSI reporting UE to follow the delay requirement signaled from the CSI triggering UE. The value of the timer is the same as the delay requirement for the SL-CSI report configured by the RRC. The timer stops when the SL CQI / RI report MAC CE is sent. If the timer expires, the MAC layer in the RX UE cancels the triggered SL CQI / RI report and cancels the corresponding pending SR. Note that if there are multiple unicast connections, the RX UE maintains a separate timer for each of them, that is, a timer is maintained for each pair of source layer-2ID and target layer-2ID corresponding to the PC5-RRC connection.

[0185] In the above method (1-4), when triggering SR for SL CQI / RI reporting, if the UE fails to receive SL grant and declares SR failure (after sending a configured number of SRs), the UE can trigger the RA process and send a SL buffer status report (BSR) for SL CQI / RI reporting during the RA process.

[0186] In the above method (1-4), when triggering the SR for SL CQI / RI reporting, if the UE fails to receive the SL grant and declares the SR failed (after sending the configured number of SRs), the UE can trigger the RA process and trigger the SL BSR for SLCQI / RI reporting. The SL BSR for SL CQI / RI reporting can be sent during the RA process (for example, in message A (MSGA) of the 2-step RA process or message 3 (Msg3) of the 4-step RA process), and the network can allocate the SL grant when receiving the SL BSR for SLCQI / RI reporting.

[0187] Issue 2: The SR configuration for SL CQI / RI reporting may not be configured to the RX UE by the gNB. In this case, when triggering the SR for SL CQI / RI reporting MAC CE, the MAC entity triggers a RA because SR resources are not available. However, the gNB cannot identify from the RA that the UE needs SL resources. If the SR configuration is not configured for SL CQI / RI reporting, some mechanism is needed to request SL resources for SL CQI / RI reporting.

[0188] In one embodiment of the present disclosure, if SR configuration is not configured for SL CQI / RI reporting, SL BSR for SL CQI / RI reporting may be triggered.

[0189] In another embodiment of the present disclosure: If SR configuration is configured for SL CQI / RI reporting, or if SL-SCH resources are available for new transmission and SL-SCH resources can accommodate SL CQI / RI reporting MAC CE plus subheader (as a result of LCP): then the UE does not trigger SL BSR for SL CQI / RI reporting. Otherwise, the UE triggers SL BSR for SL CQI / RI reporting.

[0190] In another embodiment of the present disclosure: if SR configuration is configured for SL CQI / RI reporting, or if SL-SCH resources are available for new transmission, and SL-SCH resources can accommodate SL CQI / RI reporting MAC CE plus subheader (as a result of LCP), and SL transmission in this available SL-SCH resource is not abandoned due to priority between SL and UL (priority between SL and UL is defined in TS 38.321 for NR SL communication): then UE does not trigger SL BSR for SLCQI / RI reporting. Otherwise, UE triggers SL BSR for SL CQI / RI reporting.

[0191] In another embodiment of the present disclosure: if the SR configuration is configured for SL CQI / RI reporting, or if SL-SCH resources are available for new transmission, and the SL-SCH resources can accommodate the SL CQI / RI reporting MAC CE plus its subheader (as a result of LCP), and the SL transmission in the available SL-SCH resources does not overlap with the UL SCH resources in time: then the UE does not trigger the SL BSR for SL CQI / RI reporting. Otherwise, the UE triggers the SL BSR for SL CQI / RI reporting.

[0192] In another embodiment of the present disclosure: if SR configuration is configured for SL CQI / RI reporting, or if SL-SCH resources are available for new transmission, and the SL transmission in the available SL-SCH resources does not overlap in time with the UL SCH resources: then the UE does not trigger the SL BSR for SL CQI / RI reporting. Otherwise, the UE triggers the SLBSR for SL CQI / RI reporting.

[0193] The SL BSR MAC CE used to request resources for SL LCH is used to indicate the buffer size in the SL Group (LCG) of one or more targeted LCHs. Some enhancements are required to enable the gNB to identify the resources used by the SL BSR MAC CE to request SL CQI / RI reports.

[0194] Option 1: The LCH identifier (LCID) in the MAC subheader of the SL BSR for SL CQI / RI reporting is different from the LCID in the MAC subheader of the normal SLBSR. Therefore, based on the LCID, the gNB can identify whether the SL BSR is for SL CQI / RI reporting.

[0195] Fig.11 The MAC CE format of the SL BSR according to an embodiment of the present disclosure is shown.

[0196] The MAC CE format of the SL BSR for SL CQI / RI reporting is the same as the SL BSR MAC CE. It includes the target index, LCG ID and buffer size. The target index in the SL BSR for SL CQI / RI reporting is set to the target index for SL CQI / RI reporting. The LCG field in the SL BSR for SL CQI / RI reporting is ignored by the gNB. The UE can set it to zero or a predetermined value. The buffer size in the SL BSR for SL CQI / RI reporting is ignored by the gNB because the size of the SL CQI / RI report is fixed. In another embodiment, the buffer size field can be removed.

[0197] Option 2: The LCID in the MAC subheader of the normal SL BSR and the LCID in the MAC subheader of the SL BSR for SL CQI / RI reporting are the same. The BSR MAC CE format for SL CQI / RI reporting is the same as the SL BSR MAC CE. It includes the target index, LCG ID and buffer size. The target index in the SL BSR for SL CQI / RI reporting is set to the target index for SL CQI / RI reporting. The LCG field in the SL BSR for SL CQI / RI reporting is set to the predefined LCG ID. The buffer size in the SL BSR for SL CQI / RI reporting is ignored by the gNB because the size of the SL CQI / RI report is fixed. In another embodiment, the buffer size field can be removed.

[0198] In an optional embodiment of Option 1 / 2, the target index field in the SL BSR for SL CQI / RI reporting may be ignored by the gNB. The UE may set it to zero or a predetermined value. In an optional embodiment, the target index field may not be included in the SL BSR for SL CQI / RI reporting. In an optional embodiment, the target index field and buffer size may not be included in the SL BSR for SL CQI / RI reporting.

[0199] Problem 3: According to the current procedure, for SL transmission in a SL grant, the UE selects a target as follows: Among the LCHs with data available for transmission, the UE selects a target corresponding to the LCH with the highest priority.

[0200] Alternatively, the UE selects the target L2 ID with the highest priority LCH with Bj>0 among the LCHs with data available for transmission. If there is no LCH with Bj>0, the UE selects the target L2 ID with the LCH with the highest priority among the LCHs with data available for transmission. The parameter Bj is maintained for each SL LCH as specified in TS 38.321.

[0201] The problem in the above process is that the SL MAC CE is not considered for target selection. In the existing process, only the SL SCH service data unit (SDU) is included in the MAC protocol data unit (PDU). The SL MAC CE may have a higher priority than the highest priority LCH with Bj>0 among the LCHs with data available for transmission, or if there is no LCH with Bj>0, the SL MAC CE may have a higher priority than the highest priority LCH with data available for transmission, or there may not be any LCH with data available for transmission. In all the cases listed above, the target is incorrectly selected and the transmission of the SL MAC CE may be delayed.

[0202] Proposed LCP procedure considering SL MAC CE:

[0203] Method 1:

[0204] 1. Target selection

[0205] The UE identifies whether the SL MAC CE is available for transmission.

[0206] If SL MAC CE is available for transmission: The UE identifies whether there is a SL LCH with Bj>0 among the SL LCHs with data available for transmission, or there is no SL LCH with data available for transmission.

[0207] If there is a SL LCH with Bj>0 among the SL LCHs with data available for transmission: The UE identifies whether the SL MAC CE has a higher priority than the highest priority SL LCH with Bj>0 among the SL LCHs with data available for transmission. If the SL MAC CE has a higher priority than the highest priority SL LCH with Bj>0 among the SL LCHs with data available for transmission, the UE selects the target (or target L2 ID) of the SL MAC CE. Otherwise, the UE selects the target (or target L2 ID) of the highest priority SL LCH with Bj>0.

[0208] If there is no SL LCH with Bj>0 among the SL LCHs with data available for transmission: The UE identifies whether the SL MAC CE has a higher priority than the highest priority SL LCH among the SL LCHs with data available for transmission. If the SL MAC CE has a higher priority than the highest priority SL LCH among the SL LCHs with data available for transmission, the UE selects the target (or target L2 ID) of the SL MAC CE. Otherwise, the UE selects the target (or target L2 ID) with the highest priority LCH.

[0209] If there is no SL LCH with data available for transmission, the UE selects a target (or target L2 ID) for the SL MAC CE.

[0210] Otherwise (ie if the SL MAC CE is not available for transmission): the UE identifies whether there is a SL LCH with Bj>0 in the SLLCH with data available for transmission.

[0211] If there is a SL LCH with Bj>0 among the SL LCHs with data available for transmission: the UE selects a target (or target L2 ID) with the highest priority SL LCH with Bj>0 among the SL LCHs with data available for transmission.

[0212] If there is no SL LCH with Bj>0 among the SL LCHs with data available for transmission: the UE selects a target (or target L2 ID) having a SL LCH with the highest priority among the SL LCHs with data available for transmission.

[0213] 2. The UE allocates resources to the SL MAC CE of the selected target and 'SL LCHs with Bj>0 among the SL LCHs of the selected target having data available for transmission' in decreasing priority, where the SL LCHs are allocated resources depending on Bj.

[0214] 3. If any resources remain, all SL MAC CEs available for transmission of the selected target, and all LCHs of the selected target with data available for transmission, are served in strictly decreasing priority order (regardless of the value of Bj) until the data for that LCH is exhausted or a SL grant is granted (whichever comes first). LCHs configured with the same priority should be served equally (or so depends on the UE implementation).

[0215] Method 2:

[0216] 1. Target selection

[0217] The UE identifies whether the SL MAC CE is available for transmission.

[0218] If SL MAC CE is available for transmission: The UE identifies whether there is a SL LCH with Bj>0 among the SL LCHs having data available for transmission, or there is no SL LCH having data available for transmission.

[0219] If there is a SL LCH with Bj>0 among the SL LCHs with data available for transmission: The UE identifies whether the highest priority SL MAC CE available for transmission has a higher priority than the highest priority SL LCH with Bj>0 among the SL LCHs with data available for transmission. If the highest priority SL MAC CE available for transmission has a higher priority than the highest priority SL LCH with Bj>0 among the SL LCHs with data available for transmission, the UE selects the target (or target L2 ID) of the highest priority SL MAC CE available for transmission. If the highest priority SL MAC CE is available for transmission of multiple targets, the selection of the target depends on the UE implementation, or the UE selects the target corresponding to the previously triggered SL MAC CE. Otherwise, the UE selects the target (or target L2 ID) with the highest priority SL LCH with Bj>0.

[0220] If there is no SL LCH with Bj>0 in the SL LCH with data available for transmission: The UE identifies whether the highest priority SL MAC CE available for transmission has a higher priority than the highest priority SLLCH in the SL LCH with data available for transmission. If the highest priority SL MAC CE available for transmission has a higher priority than the highest priority SL LCH in the SL LCH with data available for transmission, the UE selects the target (or target L2 ID) of the highest priority SL MAC CE available for transmission. If the highest priority SL MAC CE is available for transmission of multiple targets, the selection of the target depends on the UE implementation, or the UE selects the target corresponding to the previously triggered SL MAC CE. Otherwise, the UE selects the target (or target L2 ID) with the highest priority LCH.

[0221] If there is no SL LCH with data available for transmission, the UE selects a target (or target L2 ID) for the SL MAC CE.

[0222] Otherwise (ie if the SL MAC CE is not available for transmission): the UE identifies whether there is a SL LCH with Bj>0 in the SLLCH with data available for transmission.

[0223] If there is a SL LCH with Bj>0 among the SL LCHs with data available for transmission: the UE selects a target (or target L2 ID) with the highest priority SL LCH with Bj>0 among the SL LCHs with data available for transmission.

[0224] If there is no SL LCH with Bj>0 among the SL LCHs with data available for transmission: the UE selects a target (or target L2 ID) having a SL LCH with the highest priority among the SL LCHs with data available for transmission.

[0225] 2. The UE allocates resources to the SL MAC CE of the selected target in descending priority and 'SL LCHs with Bj>0 among the SL LCHs of the selected target having data available for transmission', where the SL LCHs are allocated resources depending on Bj.

[0226] 3. If any resources remain, all SL MAC CEs available for transmission of the selected target and all LCHs of the selected target with data available for transmission are served in strictly decreasing priority order (regardless of the value of Bj) until the data for that LCH is exhausted or a SL grant is granted (whichever comes first). LCHs configured with the same priority should be served equally (or so depends on the UE implementation).

[0227] Method 3:

[0228] 1. Target selection

[0229] The UE identifies whether the SL MAC CE is available for transmission.

[0230] If SL MAC CE is available for transmission: The UE selects the target (or target L2 ID) of the highest priority SL MAC CE available for transmission.

[0231] Otherwise, the UE identifies that there is a SL LCH with Bj>0 among the SL LCHs with data available for transmission. If there is a SL LCH with Bj>0 among the SL LCHs with data available for transmission: the UE selects a target (or target L2 ID) with the highest priority SL LCH with Bj>0 among the SL LCHs with data available for transmission. If there is no SL LCH with Bj>0 among the SL LCHs with data available for transmission: the UE selects a target (or target L2 ID) with the SL LCH with the highest priority among the SL LCHs with data available for transmission.

[0232] 2. The UE allocates resources to the SL MAC CEs of the selected targets in descending priority order.

[0233] 3. If any resources remain, then depending on Bj, the SL_LCHs with Bj>0 among the SL LCHs of the selected target having data available for transmission are served in descending priority.

[0234] 4. If any resources remain, all LCHs of the selected target that have data available for transmission are served in strictly descending priority order (regardless of the value of Bj) until the data for that LCH is exhausted or a SL is granted (whichever comes first). LCHs configured with the same priority should be served equally (or so depends on the UE implementation).

[0235] Method 4:

[0236] 1. Target selection

[0237] The UE identifies whether the SL MAC CE is available for transmission.

[0238] If SL MAC CE is available for transmission: The UE selects the target (or target L2 ID) of the highest priority SL MAC CE available for transmission. Otherwise, the UE identifies whether there is an SLLCH with Bj>0 among the SL LCHs with data available for transmission. If there is an SL LCH with Bj>0 among the SL LCHs with data available for transmission: The UE selects the target (or target L2 ID) of the highest priority SL LCH with Bj>0 among the SL LCHs with data available for transmission.

[0239] If there is no SL LCH with Bj>0 among the SL LCHs having data available for transmission: the UE selects a target (or target L2 ID) having a SL LCH with the highest priority among the SL LCHs having data available for transmission.

[0240] 2. The UE allocates resources to the SL MAC CE of the selected target in descending priority and to 'SL LCH with Bj>0 among the SL LCHs of the selected target having data available for transmission', where the SL LCH is the allocated resource depending on Bj.

[0241] 3. If any resources remain, all SL MAC CEs available for transmission of the selected target, and all LCHs of the selected target with data available for transmission, are served in strictly decreasing priority order (regardless of the value of Bj) until the data for that LCH is exhausted or a SL grant is granted (whichever comes first). LCHs configured with the same priority should be served equally (or so depends on the UE implementation).

[0242] In the above method, the SL MAC CE used for target selection may be any SL MAC CE. In one embodiment, in the above method, the SL MAC CE used for target selection may be predefined. In the above method, the SL MAC CE used for target selection may be a SL MAC CE used for CQI / RI reporting.

[0243] 4. The UE allocates resources to the SL MAC CE of the selected target in decreasing priority, and 'SL LCHs with Bj>0 among the SL LCHs of the selected target having data available for transmission', where the SL LCHs are allocated resources depending on Bj.

[0244] 5. If any resources remain, all SL MAC CEs available for transmission of the selected target, and all LCHs of the selected target with data available for transmission, are served in strictly descending priority order (regardless of the value of Bj) until the data for that LCH is exhausted or a SL grant is granted (whichever comes first). LCHs configured with the same priority should be served equally (or so depends on the UE implementation).

[0245] Fig.12 is a block diagram of a terminal according to an embodiment of the present disclosure.

[0246] Reference Fig.12 The terminal includes a transceiver 1210, a controller 1220, and a memory 1230. The controller 1220 may refer to a circuit, an ASIC, an FPGA, or at least one processor. The transceiver 1210, the controller 1220, and the memory 1230 are configured to perform the following steps: Figure 1-10 Operation of the UE as shown or described above. Although the transceiver 1210, the controller 1220, and the memory 1230 are shown as separate entities, they may be integrated into a single chip. The transceiver 1210, the controller 1220, and the memory 1230 may also be electrically connected or coupled to each other.

[0247] The transceiver 1210 may transmit and receive signals to and from other network entities (eg, base stations).

[0248] According to the above embodiment, the controller 1220 can control the UE to perform a function. For example, the controller 1220 identifies that the SL-CSI report has been triggered. If the timer for the SL-CSI report for the triggered SL-CSI report is not running, the controller 1220 starts the timer. If the timer for the triggered SL-CSI report expires, the controller 1220 cancels the triggered SL-CSI report. If the MAC entity has SL resources allocated for new transmission and the SL resources can accommodate the SL-CSI report MAC CE as well as the subheader (as a result of the logical channel priority setting), the controller 1220 stops the timer for the triggered SL-CSI report and cancels the triggered SL-CSI report. Otherwise, if the MAC entity has configured SL resource allocation mode 1, the controller 1220 triggers SR. In another embodiment, the controller 1220 selects a target that has at least one of the MAC CE and LCH with the highest priority in the MAC CE and LCH.

[0249] In one embodiment, the operation of the terminal can be implemented using a memory 1230 storing corresponding program codes. Specifically, the terminal can be equipped with a memory 1230 to store program codes that implement the desired operation. In order to perform the desired operation, the controller 1220 can read and execute the program code stored in the memory 1230 by using a processor or a central processing unit (CPU).

[0250] Fig.13 is a block diagram of a base station according to an embodiment of the present disclosure.

[0251] refer to Fig.13 , the base station includes a transceiver 1310, a controller 1320, and a memory 1330. The controller 1320 may refer to a circuit, an ASIC, an FPGA, or at least one processor. The transceiver 1310, the controller 1320, and the memory 1330 are configured to perform the operations of the gNB (or network) shown in the figure or as described above. Although the transceiver 1310, the controller 1320, and the memory 1330 are shown as separate entities, they may be integrated into a single chip. The transceiver 1310, the controller 1320, and the memory 1330 may also be electrically connected or coupled to each other.

[0252] The transceiver 1310 may transmit and receive signals to and from other network entities (eg, terminals).

[0253] According to an embodiment of the present disclosure, the controller 1320 may control the gNB to perform functions. In one embodiment, the operation of the base station may be implemented using a memory 1330 storing corresponding program codes. Specifically, the base station may be equipped with a memory 1330 to store program codes for implementing desired operations. In order to perform the desired operation, the controller 1320 may read and execute the program code stored in the memory 1330 by using a processor or a CPU.

[0254] While the present disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

[0255] Although the present disclosure has been described with various embodiments, various changes and modifications may be suggested to one skilled in the art. The present disclosure is intended to encompass such changes and modifications as fall within the scope of the appended claims.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: selecting a destination having at least one of: a medium access control MAC control element CE, and a logical channel having the highest priority among logical channels having sidelink SL data available for transmission and at least one MAC CE for SL, the logical channel having Bj>0, wherein Bj represents a parameter associated with logical channel prioritization; and allocating resources in descending order of priority to at least one logical channel selected among the logical channels of the selected destination that has data available for transmission, Therein, in case of any resource remaining, all logical channels with SL data available for transmission are served in strictly decreasing priority order until the SL data or SL grant for the logical channel is exhausted.

2. The method according to claim 1, wherein: The MAC CE is used for side link channel state information SL-CSI reporting.

3. The method according to claim 1, wherein: The MAC CE has a higher priority than the logical channel used for SL data transmission.

4. The method according to claim 1, wherein: Logical channels configured with equal priority are served equally.

5. A terminal in a wireless communication system, the terminal comprising: Transceiver; as well as A controller connected to the transceiver and configured to: selecting a destination having at least one of: a medium access control MAC control element CE, and a logical channel having the highest priority among logical channels having sidelink SL data available for transmission and at least one MAC CE for SL, the logical channel having Bj>0, wherein Bj represents a parameter associated with logical channel prioritization; and allocating resources in descending order of priority to at least one logical channel selected among the logical channels of the selected destination that has data available for transmission, Therein, in case of any resource remaining, all logical channels with SL data available for transmission are served in strictly decreasing priority order until the SL data or SL grant for the logical channel is exhausted. The terminal according to claim 5, wherein: The MAC CE is used for side link channel state information SL-CSI reporting.

7. The terminal according to claim 5, wherein: The MAC CE has a higher priority than the logical channel used for SL data transmission.

8. The terminal according to claim 5, wherein: Logical channels configured with equal priority are served equally.

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