COMMUNICATION APPARATUS AND METHOD FOR TRANSMITTER LIMITATION ON RESOURCE REPORTING IN SIDELINK COMMUNICATIONS - Patent application

Abstract

A communication apparatus and method are provided for providing radio resource selection and reporting in sidelink (SL) communication. The disclosed techniques feature a method including determining, at a transmitting user equipment (TX UE), a first set of candidate resources having a high priority from all resources for SL communication. The first set of candidate resources is determined based on at least a reference signal received power (RSRP) of the SL communication and a discontinuous reception (DRX) inactive time of a receiving UE (RX UE). The method also includes reporting a subset of all resources to a higher layer, where the subset of all resources meets a condition, and the subset of all resources includes resources of the first set of candidate resources that meet the condition.

Description

[Technical field]

[0001] The present disclosure relates generally to sidelink (SL) communications in a radio access network (RAN), and more particularly to a communications apparatus and method for transmitter-initiated restriction on resource reporting for SL communications. [Background technology]

[0002] Communications devices are prevalent in today's world in the form of phones, tablets, computers, cameras, digital audio / video players, wearables, gaming consoles, telehealth / telemedical devices, vehicles that provide communications capabilities, and various combinations thereof. Communications may include, for example, exchanging data via cellular systems, satellite systems, wireless local area network systems, and various combinations thereof.

[0003] In the development of communication systems, it was recognized that direct mode communication between User Equipment (UE) is desirable. For example, in public safety communications, direct mode communication is essential to maintain connectivity with first responders, especially when there is no network coverage. Direct mode communication was developed as Sidelink (SL) communication in the Long Term Evolution (LTE) of the Third Generation Partnership Project (3GPP). As 3GPP develops the Fifth Generation (5G) communication protocols, SL communication will be adopted from LTE.

[0004] Discontinuous reception (DRX) with active and inactive times was introduced as an enhancement to SL communication between UEs to save power. However, currently, it is only specified that the physical (PHY) layer selects and reports candidate resources to the upper layer, and at least a subset of the reported candidate resources is within the indicated DRX active time of the RX UE. There is no method and detailed procedure on how the PHY layer restricts resources to derive candidate resources, and potential issues regarding resource selection and reporting are not addressed, so there is a gap in the selection and restriction procedure in SL communication.

[0005] Therefore, what is needed is a communications apparatus and method for transmitter restriction on resource reporting for SL communications to fill the void in current resource selection and restriction procedures in SL communications and enhance the ability of a TX UE to select resources within an indicated active time of a RX UE. Additionally, other desirable features and characteristics will become apparent from the subsequent detailed description and appended claims, taken in conjunction with the accompanying drawings and the content of this Background section. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] 3GPP TS 38.300 v15.6.0 [Non-Patent Document 2] 3GPP TS 38.211 v15.6.0 [Non-Patent Document 3] ITU-R M.2083 [Non-Patent Document 4] TR 38.913 [Non-Patent Document 5] TS 23.501 v16.1.0 [Non-Patent Document 6] TS38.214 [Non-Patent Document 7] TS38.331 Summary of the Invention [Problem to be solved by the invention]

[0007] One non-limiting and exemplary embodiment facilitates providing a method and communications device for selecting and reporting resources for sidelink communications. [Means for solving the problem]

[0008] In one embodiment, the techniques disclosed herein provide a method for selecting and reporting radio resources in sidelink (SL) communication. The method includes determining, at a transmitting user equipment (TX UE), a first set of candidate resources having a high priority from all resources for SL communication. The first set of candidate resources is determined based on at least a reference signal received power (RSRP) of the SL communication and a discontinuous reception (DRX) inactive time of a receiving UE (RX UE). The method also includes reporting a subset of all resources to a higher layer, where the subset of all resources meets a condition, and the subset of all resources includes resources of the first set of candidate resources that meet the condition.

[0009] It is noted that the general or specific embodiments may be implemented as a communications device, a method, an integrated circuit, a computer program, a storage medium, or any selective combination thereof.

[0010] Further benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings, and these benefits and / or advantages may be obtained individually through the various embodiments and features of the specification and drawings, and it is not necessary for all of these features to be present in order to obtain one or more of such benefits and / or advantages. [Brief description of the drawings]

[0011] In the following, exemplary embodiments are explained in more detail with reference to the accompanying drawings. [Figure 1] 1 illustrates an example architecture of a 3GPP NR system. [Diagram 2] FIG. 1 is a schematic diagram showing the division of functions between NG-RAN and 5GC. [Diagram 3] FIG. 1 is a sequence diagram of an RRC connection setup / reconfiguration procedure. [Figure 4] FIG. 1 is a schematic diagram illustrating usage scenarios for Enhanced mobile broadband (eMBB), Massive Machine Type Communications (mMTC), and Ultra Reliable Low Latency Communications (URLLC). [Diagram 5] FIG. 1 is a block diagram illustrating an example 5G system architecture for a non-roaming scenario. [Figure 6] 1 shows a flowchart of a conventional New Radio (NR) candidate resource sensing procedure in 3GPP Release 16 (R16). [Figure 7] 1 shows a flowchart of a conventional Long Term Evolution (LTE) candidate resource sensing procedure in 3GPP Release 14 (R14). [Figure 8] 1 illustrates a block diagram of an exemplary communication device. [Figure 9] 1 shows a flowchart of radio resource selection and reporting for SL communication according to a first embodiment of the present disclosure. [Figure 10] 13 shows a flowchart of radio resource selection and reporting for SL communication according to a first variant of the first embodiment of the present disclosure. [Figure 11]13 shows a flowchart of radio resource selection and reporting for SL communication according to a second variant of the first embodiment of the present disclosure. [Figure 12] 13 shows a flowchart of radio resource selection and reporting for SL communication according to a second embodiment of the present disclosure. [Figure 13] 13 shows a flowchart of radio resource selection and reporting for SL communication according to a third embodiment of the present disclosure. [Figure 14] 13 shows a flowchart of radio resource selection and reporting for SL communication according to a fourth embodiment of the present disclosure. [Figure 15] 13 shows a flowchart of radio resource selection and reporting for SL communication according to a fifth embodiment of the present disclosure. [Figure 16] 13 shows a flowchart of radio resource selection for SL communication according to a sixth embodiment of the present disclosure. [Figure 17] 13 shows a flowchart of radio resource selection for SL communication according to a variant of the sixth embodiment of the present disclosure.

[0012] Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The following detailed description is merely exemplary in nature and is not intended to limit the example embodiments or the application and uses of the example embodiments. Moreover, there is no intention to be bound by any theory presented in the preceding background section or the following detailed description.

[0014] <5G NR system architecture and protocol stack> 3GPP is working on the next release of fifth-generation cellular technology (known simply as 5G), which includes the development of a new radio access technology (NR) that will operate in frequencies up to 100 GHz. The first version of the 5G standard will be completed at the end of 2017, which will allow smartphones compliant with the 5G NR standard to proceed to testing and commercial deployment.

[0015] In particular, the overall system architecture envisages an NG-RAN (Next Generation - Radio Access Network) with gNBs, which terminate NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols towards the UEs. The gNBs are interconnected with each other by an Xn interface. Furthermore, the gNBs are connected to an NGC (Next Generation Core) by a Next Generation (NG) interface, more specifically to an AMF (Access and Mobility Management Function) (e.g. a specific core entity running AMF) by an NG-C interface, and to a UPF (User Plane Function) (e.g. a specific core entity running UPF) by an NG-U interface. Figure 1 shows the architecture of an NG-RAN (see, for example, section 4 of Non-Patent Document 1).

[0016] The user plane protocol stack in NR (see, for example, section 4.4.1 of 3GPP) includes the PDCP (Packet Data Convergence Protocol, see section 6.4 of 3GPP), RLC (Radio Link Control, see section 6.3 of 3GPP), and MAC (Medium Access Control, see section 6.2 of 3GPP), which are terminated in the gNB on the network side. In addition, a new sublayer of the access stratum (AS), SDAP (Service Data Adaptation Protocol), is introduced on top of PDCP (see, for example, section 6.5 of 3GPP). A control plane protocol stack is also defined in NR (see, for example, section 4.4.2 of 3GPP). An overview of the functions of Layer 2 is given in section 6 of 3GPP. The functions of the PDCP sublayer, the RLC sublayer, and the MAC sublayer are respectively described in clauses 6.4, 6.3, and 6.2 of 3GPP TS 2011-010111. The functions of the RRC layer are described in clause 7 of 3GPP TS 2011-010111.

[0017] The Medium Access Control (MAC) layer handles, for example, multiplexing of logical channels, and scheduling and scheduling-related functions (including handling of various numerologies).

[0018] The physical layer (PHY) is responsible for, for example, coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. Furthermore, the physical layer (PHY) handles mapping of transport channels to physical channels. The physical layer (PHY) provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for the transmission of a particular transport channel, and each transport channel is mapped to a corresponding physical channel. For example, the physical channels are PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel) for the uplink, and PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel) for the downlink.

[0019] NR use cases / deployment scenarios include enhanced Mobile Broadband (eMBB), ultra-reliable and low latency communications (URLLC), and massive machine type communications (mMTC), which have diverse requirements in terms of data rates, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps downlink (DL) and 10 Gbps uplink (UL)) and user-perceived data rates that are on the order of three times higher than those offered by IMT-Advanced. In contrast, URLLC has more stringent requirements, including extremely low latency (user plane latency of 0.5 ms for uplink and downlink, respectively) and high reliability (1-10 Gbps within 1 ms). -5) is imposed. In addition, mMTC requires high connection density (1 km 2 1,000,000 devices per second), wide coverage in harsh environments, and extremely long battery life (15 years) to lower device costs may be desirable.

[0020] Thus, an OFDM numerology (e.g., subcarrier spacing, OFDM symbol duration, cyclic prefix (CP) duration, number of symbols per scheduling interval) suitable for one use case may not work well for another use case. For example, low latency services may preferably require a shorter symbol duration (and therefore a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also referred to as TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer cyclic prefix (CP) duration than scenarios with small delay spreads. To maintain a similar cyclic prefix (CP) overhead, the subcarrier spacing should be optimized depending on the delay spread. In NR, more than one value of subcarrier spacing may be supported. Thus, currently, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, ... are considered. Symbol duration T u and the subcarrier spacing Δf is expressed by the formula Δf=1 / T u As in LTE systems, the term "resource element" can be used to denote the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0021] In the new wireless system 5G-NR, for each numerology and carrier, a resource grid of subcarriers and OFDM symbols is defined for both the uplink and the downlink respectively. Each element in the resource grid is called a resource element and is identified based on the frequency index in the frequency domain and the symbol position in the time domain (see Non-Patent Document 2).

[0022] <Split of 5G NR Functions between NG-RAN and 5GC> Figure 2 shows the split of functions between NG-RAN and 5GC. The logical nodes of NG-RAN are gNB or ng-eNB. The logical nodes of 5GC are AMF, UPF, and SMF.

[0023] gNB and ng-eNB handle the following main functions in particular. - Functions of radio resource management such as radio bearer control, radio admission control, connection mobility control, and dynamic resource allocation (scheduling) to the UE in both the uplink and the downlink - IP header compression, encryption, and data integrity protection - Selection of AMF at UE attachment when the routing to AMF cannot be determined from the information provided by the UE - Routing of user plane data to UPF - Routing of control plane information to AMF - Establishment and release of connections - Scheduling and transmission of paging messages - Scheduling and transmission of system broadcast information (sent from AMF or OAM) - Configuration of measurements and measurement reports for mobility and scheduling - Transport-level packet marking in the uplink - Session Management - Network slicing support - QoS flow management and mapping to data radio bearers - Support for UEs in RRC_INACTIVE state - NAS message delivery function - Wireless Access Network Sharing - Dual Connection - Tight interworking between NR and E-UTRA

[0024] The Access and Mobility Management Function (AMF) handles the following main functions: - Termination of Non-Access Stratum (NAS) signalling - NAS signaling security - Access Stratum (AS) security control - Core Network (CN) inter-node signaling for mobility between 3GPP access networks - Idle mode UE reachability (including control and execution of paging retransmissions) - Registration Area Management - Support for intra-system and inter-system mobility - Access Authentication - Access authentication, including roaming rights checks - Mobility management controls (subscriptions and policies) - Network slicing support - Selection of Session Management Function (SMF)

[0025] In addition, the User Plane Function (UPF) handles the following main functions: - Anchor points for RAT-internal / RAT-inter RAT mobility (when applicable) - External PDU session point of interconnection with the data network - Packet routing and forwarding - User plane part of packet inspection and policy rule enforcement - Traffic usage reporting - Uplink classifier to support routing of traffic flows to the data network - Branching point to support multi-homed PDU sessions - User plane QoS handling (e.g., packet filtering, gating, UL / DL rate enforcement) - Verification of uplink traffic (mapping from SDF to QoS flow) - Downlink packet buffering and triggering of downlink data notifications

[0026] Finally, the Session Management Function (SMF) processes the following main functions. - Session management - Allocation and management of UE IP addresses - Selection and control of the UP function - Configuration of traffic steering in the User Plane Function (UPF) to route traffic to the correct destination - Policy enforcement and QoS control part - Downlink data notification

[0027] <RRC connection setup and reconfiguration procedures> Figure 3 shows a part of the interaction between the UE, gNB, and AMF (5GC entity) in the NAS part when the UE transitions from RRC_IDLE to RRC_CONNECTED (see Non-Patent Document 1).

[0028] RRC is a higher layer signaling (protocol) used for the configuration of the UE and the gNB. In particular, in this transition, the AMF creates UE context data (including e.g. PDU session context, security keys, UE radio capabilities, UE security capabilities, etc.) and sends it to the gNB via an INITIAL CONTEXT SETUP REQUEST. The gNB then activates AS security with the UE, which is performed by the gNB sending a SecurityModeCommand message to the UE and the UE responding with a SecurityModeComplete message to the gNB. The gNB then performs a reconfiguration to set up the signaling radio bearer 2 (SRB2) and data radio bearer (DRB), which is performed by the gNB sending an RRCReconfiguration message to the UE and the gNB receiving an RRCReconfigurationComplete from the UE in response. In case of a signaling only connection, these steps related to RRCReconfiguration are skipped since SRB2 and DRB are not set up. Finally, the gNB informs the AMF that the setup procedure is complete via an INITIAL CONTEXT SETUP RESPONSE.

[0029] In the present disclosure, a fifth generation core (5GC) entity (e.g., AMF, SMF, etc.) is thus provided, comprising a control circuit that, during operation, establishes a next generation (NG) connection with a gNodeB, and a transmitter that, during operation, transmits an initial context setup message to the gNodeB via the NG connection to set up a signaling radio bearer between the gNodeB and a user equipment (UE). In particular, the gNodeB transmits radio resource control (RRC) signaling including a resource allocation configuration information element to the UE via the signaling radio bearer. The UE then performs uplink transmission or downlink reception based on the resource allocation configuration.

[0030] <IMT usage scenario after 2020> Figure 4 shows some of the use cases for 5G NR. The 3GPP (3rd Generation Partnership Project) New Radio (3GPP NR) considers three use cases envisaged to support various services and applications with early IMT-2020. The specifications for Phase 1 of Enhanced Mobile Broadband (eMBB) have been finalized. Current and upcoming work includes the standardization of Ultra-Reliable and Low-Latency Communications (URLLC) and Large-Scale Machine-Type Communications, in addition to further extending support for eMBB. Figure 4 shows some examples of usage scenarios envisaged for IMT-2000 and beyond (see, for example, Figure 2 in Non-Patent Document 3).

[0031] URLLC use cases have stringent requirements on capabilities such as throughput, latency and availability, and are envisioned as one of the enablers of future vertical applications such as wireless control of industrial manufacturing and production processes, remote medical surgery, power distribution automation in smart grids, and transportation safety. URLLC's ultra-high reliability is supported by identifying technologies to meet the requirements set by NR URLLC in Release 15. Key requirements for NR URLLC include a target user plane latency of 0.5 ms for each of the UL (uplink) and DL (downlink). The general URLLC requirement for a single transmission of a packet is a BLER (block error rate) of 1E-5 for a packet size of 32 bytes with a user plane latency of 1 ms.

[0032] From a physical layer perspective, there are several possible ways to improve reliability. Currently, there are measures to improve reliability, such as the definition of a separate CQI table for URLLC, more compact DCI formats, and PDCCH repetition. However, as NR becomes more stable and developed (a key requirement for NR URLLC), the scope for achieving ultra-high reliability may increase. Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0033] Furthermore, technology enhancements targeted by NR URLLC target latency improvement and reliability improvement. Technology enhancements for latency improvement include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition of data channel, and preemption for downlink. Preemption means that a transmission for which resources are already allocated is aborted and the already allocated resources are used for another transmission with smaller latency / higher priority requirement requested later. Thus, an already granted transmission is preempted by a later transmission. Preemption applies regardless of service type. For example, a transmission of service type A (URLLC) can be preempted by a transmission of service type B (eMBB, etc.). Technology enhancements related to reliability improvement include dedicated CQI / MCS tables for a target BLER of 1E-5.

[0034] The mMTC (Massive Machine Type Communication) use case is characterized by a very large number of connected devices transmitting relatively small amounts of data that are generally not sensitive to latency. The devices are required to be low cost and have extremely long battery life. From an NR perspective, utilizing very narrow bandwidth portions is one possible solution to achieve power saving from the UE perspective to enable long battery life.

[0035] As mentioned above, it is expected that the scope of reliability in NR will expand. One key requirement for all cases, especially for URLLC and mMTC, is high or ultra-high reliability. Several mechanisms can be considered to improve reliability from a radio perspective and from a network perspective. In general, there are several key areas that can help improve reliability. These areas include compact control channel information, data channel / control channel repetition, diversity related to frequency domain, time domain, and / or spatial domain. These areas are generally applicable to reliability, regardless of the specific communication scenario.

[0036] For NR URLLC, further use cases with more stringent requirements have been identified, such as factory automation, transportation, and power distribution. The more stringent requirements include higher reliability (up to 10 times faster) depending on the use case. -6 These include: high-speed, low latency, high-speed (high-speed), higher availability, packet sizes up to 256 bytes, time synchronization on the order of a few microseconds (1 μs to a few μs depending on the frequency range), and low latency on the order of 0.5-1 ms, with a target user plane latency of 0.5 ms in particular.

[0037] Furthermore, in the case of NR URLLC, several technical enhancements have been identified from a physical layer perspective. In particular, enhancements related to PDCCH (Physical Downlink Control Channel) include compact DCI, repetition of PDCCH, and increased PDCCH monitoring. Also, enhancements related to UCI (Uplink Control Information) include enhancements of HARQ (Hybrid Automatic Repeat reQuest) and CSI feedback. In addition, enhancements of PUSCH related to mini-slot level hopping and enhancements of retransmission / repetition have also been recognized. The term "mini-slot" means a TTI (Transmission Time Interval) that includes a smaller number of symbols than a slot (a slot includes 14 symbols).

[0038] <QoS control> The 5G QoS (Quality of Service) model is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (GBR QoS flows) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Therefore, at the NAS level, a QoS flow is the finest granularity for QoS differentiation in a PDU session. A QoS flow is identified within a PDU session by a QoS flow ID (QFI) that is transmitted within a capsule header through the NG-U interface.

[0039] The 5GC establishes one or more PDU sessions for each UE. The NG-RAN establishes at least one Data Radio Bearer (DRB) for each UE together with the PDU session, and may then configure additional DRBs for the QoS flows of that PDU session (NG-RAN decides when to do so), e.g. as described above with reference to Figure 3. The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filters in the UE and 5GC associate UL and DL packets with QoS flows, and AS-level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0040] Figure 5 shows the non-roaming reference architecture of 5G NR (see section 4.23 of non-patent document 5). Application Functions (AFs) (e.g., external application servers handling 5G services exemplarily described in Figure 4) interact with the 3GPP core network to provide services. For example, they support application influence on traffic routing, access Network Exposure Functions (NEFs), and interact with a policy framework (see Policy Control Function (PCF)) for policy control (e.g., QoS control). Based on the operator's deployment, application functions (AFs) that are considered trusted by the operator can be allowed to interact directly with the relevant network functions (Network Functions). Application functions (AFs) that are not allowed by the operator to directly access network functions interact with the relevant network functions using an external exposure framework via the NEF.

[0041] Figure 5 shows further functional units of the 5G architecture: Network Slice Selection Function (NSSF), Network Repository Function (NRF), Unified Data Management (UDM), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), and Data Network (DN) (e.g. operator services, Internet access, or third-party services). All or part of the core network functions and application services may be deployed and run on a cloud computing environment.

[0042] Thus, in the present disclosure, an application server (e.g., an AF in a 5G architecture) is provided having a transmitter and a control circuit, wherein the transmitter, during operation, sends a request including QoS requirements for at least one of a URLLC service, an eMMB service, and an mMTC service to at least one of the 5GC functions (e.g., NEF, AMF, SMF, PCF, UPF, etc.) to establish a PDU session including a radio bearer between a gNodeB and a UE in accordance with the QoS requirements, and the control circuit, during operation, performs the service using the established PDU session.

[0043] <Embodiment> The intent of the present disclosure is to present exemplary embodiments of a communication apparatus and method for resource restriction in sidelink (SL) communication by classifying candidate resources with different priorities for resource reporting to a MAC layer of a transmitting user equipment (TX UE). Furthermore, the present disclosure presents exemplary embodiments of a method for resource restriction by prioritizing candidate resources within an indicated active time within discontinuous reception (DRX) of a SL communication in a receiving user equipment (RX UE), which includes, for example, stepwise increasing a threshold related to reference signal received power (RSRP) up to a maximum threshold or up to a maximum number of iterations to optimize the selection of available resources within the indicated active time of the RX UE.

[0044] Within the 3GPP Technical Specification Group Radio Access Network (TSG RAN), 3GPP TNG RAN WCL1 (RAN1) is responsible for the specifications of the air interface physical (PHY) layer in UE, Evolved UTRAN, and NG-RAN. 3GPP TNG RAN WG2 (RAN2) is responsible for the air interface architecture and protocols such as MAC, RLC, PDCP, SDAP, Radio Resource Control 1 protocol specifications, and radio resource management procedures.

[0045] In Release 17 (R17), Discontinuous Reception (DRX) with active and inactive times was introduced as an extension of SL communication between UEs. DRX was introduced in SL to save power, but currently all that is specified in RAN1 is that the PHY layer selects and reports candidate resources to higher layers, and at least a subset of the reported candidate resources is within the indicated DRX active time of the RX UE. There is no method or detailed procedure on how the PHY layer constrains resources to derive candidate resources, and potential issues with resource selection and reporting are not addressed.

[0046] In RAN2, resource selection in TX UE when communicating with RX UE in DRX was discussed. First, based on the RAN2 agreement, RAN2 knows the following about TX UE: (a) in case of unicast, for each pair of source Layer 2 ID and destination Layer 2 ID, TX UE maintains a set of timers corresponding to SL DRX timers of RX UE, (b) in case of groupcast or broadcast, for each destination Layer 2 ID, TX UE maintains a set of timers corresponding to SL DRX timers of RX UE, (c) TX UE uses the timers as part of the criteria to determine the allowed transmission time for each RX UE. For transmission to RX UE using SL DRX operation, logical channel prioritization (LCP) restrictions ensure that TX UE transmits data within the active time of RX UE.

[0047] Additionally, in RAN2#115-e, RAN2 agreed to the following:

[0048] (i) When data is available for transmission to one or more RX UEs in DRX, the TX UE selects resources taking into account the active time (present or future) of the RX UEs, which is determined by a timer maintained in the TX UE. Details and whether RAN1 or RAN2 enforces this restriction will be discussed further.

[0049] (ii) In the case of unicast, the TX UE selects the resource for the first transmission that is associated with the active time (e.g., on-duration timer or inactivity timer, or retransmission timer) in the RX UE. How to handle when a transmission may cause these timers to operate for groupcast in the RX UE and whether this affects the communication specifications will be considered further.

[0050] (iii) In the case of unicast, the TX UE may select resources for retransmission that are associated with any active time at the RX UE (e.g., based on a duration timer or an inactivity timer, or based on a retransmission timer). How to handle when a transmission may cause these timers to operate for groupcast at the RX UE and whether this affects the communication specifications will be considered further.

[0051] (iv) In case of broadcast, the TX UE may select a resource for the first transmission that is associated with an active time (ie, on-duration) supported by broadcast in the RX UE.

[0052] (v) Also, in case of broadcast, the TX UE may select resources for retransmission associated with active times (ie, on-periods) supported by broadcast in the RX UE.

[0053] RAN2 then asks RAN1 to take the above agreement into account and whether or how RAN1 intends to reflect limitations in the initial RAN2 agreement, i.e. "When data is available to transmit in DRX to one or more RX UEs, the TX UE shall select resources taking into account the active time (current or future) of the RX UE as determined by a timer maintained in the TX UE." In other words, the PHY considers the DRX active time indicated by the MAC layer to the RX UE for the candidate resources and considers whether or how to reflect the limitations of the resources.

[0054] At the RAN1#106bis-e meeting, it was concluded as a Working Assumption that the physical layer restrictions apply when the PHY layer is indicated with the active time of the RX UE. When the PHY layer is indicated with the active time of the RX UE by the MAC layer for the selection of candidate resources, restrictions are applied at the PHY layer such that at least a subset of the candidate resources reported to the MAC layer are located within the indicated active time of the RX UE.

[0055] The following options are further discussed in RAN1 to restrict resources taking into account the active time indicated by the MAC layer to select candidate resources:

[0056] Option 1: The PHY layer selects and reports candidate resources only within the indicated active time of the RX UE.

[0057] Option 2: The PHY layer selects and reports candidate resources where at least a subset of the candidate resources is within the indicated active time of the RX UE.

[0058] Option 3: The PHY layer selects and reports an additional candidate resource set of candidate resources within the indicated active time of the RX UE.

[0059] At the RAN1#107-e meeting, it was further agreed that for option 2, the PHY layer shall select and report candidate resources where at least a subset of the candidate resources is within the indicated active time of the RX UE. When the SL DRX active time of the RX UE is provided by higher layers for candidate resource selection (including resource (re)selection and re-evaluation / preemption checks), for option 2, the following working assumptions RAN1#106bis-e were confirmed as agreed:

[0060] When the PHY layer is indicated by the MAC layer the active time of the RX UE for candidate resource selection, the restriction is applied at the PHY layer such that at least a subset of the candidate resources reported to the MAC layer is located within the indicated active time of the RX UE. Option 2: The PHY layer selects and reports candidate resources where at least a subset of the candidate resources is within the indicated active time of the RX UE. Furthermore, the following options are left for further discussion to implement the candidate resource restriction considering the indicated active time from the MAC layer: (a) details when the number of subset of candidate resources is less than a threshold, (b) whether each inactive time should be considered for the subset of candidate resources outside the active time, (c) whether the UE selects the resource selection window to overlap with the indicated active time of the RX UE, and (d) whether it is dependent on the UE implementation to report the candidate resources only within the indicated active time of the RX UE.

[0061] However, the problem is that currently, all that is specified in RAN1 is that the PHY layer selects and reports candidate resources for which at least a subset of the candidate resources is within the indicated DRX active time of the RX UE. No detailed procedure or guidance is provided on how the PHY layer should restrict such candidate resources. Furthermore, some potential issues with resource selection and reporting are not addressed.

[0062] One possible solution by those skilled in the art is a pure MAC layer operation (i.e., without physical layer restrictions) where the PHY layer performs legacy procedures such as in Non-Patent Document 6. After receiving the candidate resources reported from the PHY layer, the MAC layer can only select among the reported candidate resources within the indicated active time of the RX UE, and the selected resource is used for the designated SL transmission. This pure MAC layer solution is less flexible compared to the PHY layer solution, since it only has the option of selecting or not selecting from a certain set of candidate resources. Separating resources with different qualities through measurements such as Reference Signal Received Power (RSRP) measurements for SL communication cannot be achieved at the MAC layer.

[0063] Another possible solution is to select purely randomly from the candidate resources within the indicated RX UE active time. Random selection does not require complex procedures. However, a purely random selection solution cannot exclude unsuitable and noisy resources.

[0064] 6 and 7, conventional fifth generation (5G) and fourth generation (4G) candidate resource sensing procedures are shown. FIG. 6 shows a flow chart 600 of a conventional New Radio (NR) candidate resource sensing procedure for 5G in 3GPP Release 16 (R16). In an initialization step 602, the term S A All M total In step 604, if some candidate resources satisfy a certain condition, the candidate resources are set as S A Next, in step 606, the remaining number of candidate resources is subtracted from the total number of candidate resources (M total ) is less than the proportion X of the remaining candidate resources. total If it is less than 1, then in step 608, the reference signal received power (RSRP) threshold Th(p i ,p j) by 3 decibels and repeat the step 604 of removing candidate resources. total If not, then in step 610, a set of non-excluded candidate resources S B Report to higher levels.

[0065] 7 shows a flow chart 700 of a conventional Long Term Evolution (LTE) candidate resource sensing procedure in 3GPP Release 14 (R14). In an initialization step 702, the term S A All M total Set the term S to be equal to the set of candidate resources B In step 704, if some candidate resources satisfy a certain condition, they are set as S A Next, in step 706, the set S A The remaining number of candidate resources in total In step 706, it is determined whether the set S A The remaining number of candidate resources in total If it is less than 20 percent of the set S, then in step 708 the threshold Th(a,b) is increased by 3 decibels and the exclusion step 704 is repeated. A The remaining number of candidate resources in total , then in a sorting step 710, the set S with the lowest RSRP is selected. A Set candidate resources in S A From Set S B In step 712, the set S B The number of candidates in total Determine whether the set S is less than 20% of the set S. B The number of candidates in total The sorting step 710 is repeated until the set S is not less than 20 percent of B The remaining number of candidates in totalIf not, then in step 714, the set of candidate resources S B Report to higher levels.

[0066] Referring to FIG. 8, a simplified block diagram 800 illustrates an exemplary communication apparatus 810, such as a user equipment (UE) operating in a wireless communication system that transmits and receives communications between the user equipment and a communication network. In accordance with the present disclosure, the communication apparatus 810 may also directly communicate with other UEs via sidelink (SL) communications. The communication apparatus 810 may include a device, such as a processor 812 coupled to a wireless communication device (e.g., a transceiver 814) connected to an antenna 816, for performing functions of SL communications described in the present disclosure. For example, the communication apparatus 810 may include a processor 812 that generates control signals and / or data signals used by the transceiver 814 to perform communication functions on selected resources of the communication apparatus 810. The communication apparatus 810 may also include a memory 818 coupled to the processor 812 for storing instructions and / or data for generating the control signals and / or data signals by the processor 812. Communications device 810 may also include input / output (I / O) circuitry 820 coupled to processor 812 for receiving input of data and / or instructions for storing in memory 818 and / or for generating control and / or data signals, and for providing output of data in the form of audio, video, text, or other media. At least processor 812 and memory 818 may be collectively referred to as circuitry of communications device 810.

[0067] According to the present disclosure, a method for restricting candidate resources for reporting to higher layers is provided. For a TX UE in SL communication considering the DRX information of the RX UE, when the TX UE selects and reports the candidate resources, the restriction is applied to the resources of the TX UE according to different priorities of the candidate resources. Set S A contains all TX UE resources, and the set S Rincludes candidate resources within the indicated DRX active time of the RX UE of the resource selection window of the TX UE. According to the method of the present disclosure, a first set of candidate resources with the "best quality" (i.e., highest priority) is considered first, such as candidate resources that are within the indicated active time of the RX UE and are below a threshold associated with the RSRP. Thus, the method of radio resource selection and reporting for sidelink (SL) communication according to the present disclosure includes, at the TX UE, determining a first set of candidate resources with high priority from all resources for the TX UE SL communication. The first set of candidate resources is determined based on at least the RSRP of the SL communication and the DRX inactive time of the RX UE. The method also includes reporting a subset of all resources to the upper layer, where the subset of all resources meets the condition, including the resources of the first set of candidate resources that meet the condition.

[0068] If the highest quality / highest priority candidate resource is less than a pre-configured percentage of the number of all candidate resources, then the "second best quality" candidate resource, the "third best quality" candidate resource, etc. that meets the criteria will be included in the subset of resources reported to higher layers.

[0069] In the TX UE, when the PHY layer is informed of the active time of the RX UE for SL communication, R Candidate resources that are within and below a threshold associated with the RSRP determined by sensing are considered the "best quality" candidate resources (i.e., the first set of candidate resources). The "best quality" candidate resources are prioritized for inclusion in the set of candidate resources reported to the MAC layer (i.e., the subset of all resources reported to higher layers). If there are not enough "best quality" resources, S R Also included are "second-best" candidate resources that are within the SRP but above the threshold associated with RSRP. These "second-best" candidate resources are RThe more resources in , the less transmission failures due to DRX for RX UEs will occur, but the more in-air interference may occur.

[0070] 9, a flowchart 900 illustrates a first embodiment of a method for radio resource selection and reporting for SL communication according to the present disclosure, in which a TX UE of the SL communication triggers a resource report that takes into account DRX information of one or more RX UEs (902). R is a candidate resource S A If the initial set (all candidate resources) of R Let all candidate resources in S A Included in (906), S R S containing all candidate resources A , perform an exclusion procedure (908) for inapplicable resources (e.g., preempted resources) in , and exclude additional resources (i.e., initial A From S R 9. If the number of resources in the non-excluded resources (i.e., the remaining resources after the exclusion step 908 and the legacy exclusion step 910) is less than S, then the legacy exclusion procedure is performed (910) on the non-excluded resources (i.e., the remaining resources after the exclusion step 908 and the legacy exclusion step 910). A If it is less than a preset X% of RSRP (912), then increase the threshold by 3 dB (or other preset increment value) (914) and iteratively perform legacy exclusion step 910 to exclude additional resources based on the increased threshold relative to the RSRP. Note that different increment values ​​(i.e., preset increment values) may be applied in different iterations and / or in different steps and / or for resources of different quality.

[0071] The number of resources in the non-excluded resource group is S. A If the set S contains non-excluded resources, then the set S contains non-excluded resources. A 9 to the MAC layer, and optionally, A Rank the first X% of by RSRP.

[0072] S R is the initial S A If it is greater than or equal to X% of (904), then S R Let all candidate resources in S A Then, the step of excluding non-applicable resources is performed (920), and the non-excluded resources are included in the initial S A It is determined whether the number of non-excluded resources is less than X% of the initial S (922). A If the remaining S is not less than X%, report the non-excluded resource (916). A If the number of non-excluded resources in is less than X%, then the legacy exclusion step 910 is iteratively performed to exclude additional resources based on an increased threshold associated with the RSRP, in this case increasing the threshold by 3 dB (or other pre-configured value) (914). Thus, the flowchart 900 illustrates a method for radio resource selection and reporting for SL communications according to the present disclosure, and includes steps for selecting and reporting radio resources for SL communications according to the present disclosure, in accordance with the present disclosure. A When less than X% of the resources are included in the subset of resources to be reported, a threshold associated with the RSRP is iteratively increased until the subset of resources includes more than X% of the resources.

[0073] Referring to FIG. 10, a flowchart 1000 for selecting and reporting radio resources for SL communication according to a first variant of the first embodiment of the present disclosure is shown. R To include the “best quality” candidate resources in the remaining set S, we select only the candidate resources below the threshold associated with RSRP. A (1002). The remaining set S A Perform the exclusion step 1004 for the inapplicable resources in S AIf the candidate resources in are still less than X% of all resources (1006), then R Determine (1008) whether any candidate resource in S exceeds a threshold value; R All resources in (1008) or the remaining S A Include the “second-best quality” resources by iteratively increasing the threshold (1010) until the candidate resources in are at least X% of all resources (1006). A If the candidate resources in are greater than or equal to X% of all resources (1006), the remaining S A report (1012) candidate resources in the remaining S A Rank the first X% of candidate resources in by RSRP.

[0074] S A If the candidate resources in are still less than X% of all resources (1006) and exceed the threshold, R If the resource does not exist (1008), the remaining S A If candidate resources have all resources S A By repeatedly incrementing RSRP (1010) until it reaches X% of the initial S A -S R ) by performing a legacy elimination procedure (1014) on the remaining S A Include the "third highest quality" resource in the candidate resources in the remaining S A Candidate resources in all resources S A If it is greater than X% (1016), the remaining S A report (1012) candidate resources in the remaining S AThe first X% of candidate resources in the resource list are ranked by RSRP. In this way, the "best quality" resource, the "second best quality" resource, and the "third best quality" resource are included in the subset of resources to be reported, thereby prioritizing the resources in the subset. The initial value of the threshold related to the RSRP may be different between the "second best quality" resource and the "third best quality" resource, or between the resource with the DRX active time of the RX UE and the resource with the DRX inactive time of the RX UE. The initial value of the threshold related to the RSRP for the "second best quality" resource or the resource with the DRX active time of the RX UE may be smaller or larger than the threshold for the "third best quality" resource or the resource with the DRX inactive time of the RX UE.

[0075] As a variation of the method of flowchart 1000, S R Instead of performing step 1010 until the resource does not exceed the iteratively increasing threshold, S R Step 1018 can be performed until the resources no longer exceed the iteratively increasing threshold or until step 1010 has been performed a maximum number of iterations (e.g., N iterations); this second variation is not shown in flowchart 1000 but is described below with respect to FIG. 12.

[0076] 11 shows a flowchart 1100 of a second variant of the first embodiment of the present disclosure. In this second variant, the “second best quality” candidate resource is one that is below the threshold associated with RSRP but has S R This definition of the "second best quality" candidate resource has the advantage that radio interference is reduced due to limited RSRP, but more transmission failures may occur due to transmissions that may be outside the DRX active time of the RX UE.

[0077] S RTo include the “best quality” candidate resources in,we select only the candidate resources that are below the,RSRP-related threshold from the remaining set,S,. A (1102). The remaining set S A Perform the exclusion step 1104 for the inapplicable resources in S A If the candidate resources in are still less than X% of all resources (1106), then a set of additional resources (i.e., the initial S A -S R ) and execute the legacy exclusion procedure (1108). A If the candidate resources in are still less than X% of all resources (1110), the remaining S A The candidate resources of are all resources S A The threshold associated with the RSRP is increased by iterations of RSRP increment 1112 to obtain the "third highest quality" candidate resource, until it reaches X% of the remaining S A Candidate resources in are all resources S A If it is greater than X% of (1106,1110), the remaining S A report (1114) candidate resources in A Rank the first X% of candidate resources in by RSRP. Thus, the "second best" candidate resource is one that falls below the threshold associated with RSRP. R DRX UEs may include resources that are not within the DRX active time, which may increase transmission failures due to transmissions that may be outside the DRX active time of the RX UE, but reduces radio interference due to the restricted RSRP.

[0078] 12, a flowchart 1200 illustrates a second embodiment of the present disclosure. In this second embodiment, a maximum number of iterations of the increasing threshold is included, which reduces S R Advantageously, the less noisy resources contained in are restricted.

[0079] S RTo include the “best quality” candidate resources in,we select only the candidate resources that are below the,RSRP-related threshold from the remaining set,S,. A (1202). The remaining set S A Execute the exclusion step 1204 for the inapplicable resources in S A If the candidate resources in are still less than X% of all resources (1206), then we add an additional set of resources (i.e., the initial S) to obtain the “second highest quality” candidate resource. A -S R ) and perform the legacy exclusion procedure (1208). A If the candidate resources in are still less than X% of all resources (1210), then the threshold associated with the RSRP is increased by iterations of RSRP increment 1212 up to a maximum number of iterations N (1214) to obtain a "third best quality" candidate resource. If the number of iterations is less than N (1214), then the process returns to step 1202. If the number of iterations is greater than or equal to N (1214), then an additional set of resources (i.e., the initial S) is selected to obtain a "fourth best quality" candidate resource. A -S R ) and perform the legacy exclusion procedure (1208). A Candidate resources in all resources S A If it is greater than X% of (1206, 1210), the remaining S A report (1216) candidate resources in the A Rank the first X% of candidate resources in by RSRP.

[0080] 13 shows a flowchart 1300 of a third embodiment of the present disclosure. This third embodiment is similar to the second embodiment of FIG. 12, except that instead of a maximum number of iterations of increasing the threshold, a maximum threshold level of the threshold associated with the RSRP is included, which reduces the S R This provides the advantage of limiting the amount of noisy resources included in

[0081] S RTo include the “best quality” candidate resources in,we select only the candidate resources that are below the,RSRP-related threshold from the remaining set,S,. A (1302). The remaining set S A Execute the exclusion step 1304 for the inapplicable resources in S A If the candidate resources in are still less than X% of all resources (1306), then a set of additional resources (i.e., the initial S A -S R ) and perform the legacy exclusion procedure (1308). A If the candidate resources in are still less than X% of all resources (1310), the RSRP-related threshold is increased by iterations of RSRP increments 1312 until a maximum RSRP-related threshold MaxTh is reached (1314) to obtain a "third best quality" candidate resource. If the RSRP-related threshold is less than MaxTh (1314), the process returns to step 1302. However, if the RSRP-related threshold is greater than or equal to MaxTh (1314), an additional set of resources (i.e., the initial S) is increased to obtain a "fourth best quality" candidate resource. A -S R ) and perform the legacy exclusion procedure (1308). A Candidate resources in all resources S A If it is greater than X% of (1306, 1310), the remaining S A report (1316) candidate resources in the A Rank the first X% of candidate resources in by RSRP.

[0082] In this way, by including the maximum number of iterations to increase the threshold, we can obtain a less noisy resource, S RThe inclusion of MaxTh in the candidate resource with DRX active time of RX UE is restricted. MaxTh may be configured for the candidate resource with DRX inactive time of RX UE and the candidate resource with DRX inactive time of RX UE, and the value of MaxTh may be different between them. The value of MaxTh for the candidate resource with DRX active time of RX UE may be smaller or larger than the value for the candidate resource with DRX inactive time of RX UE.

[0083] 14, a flow chart 1400 illustrates a fourth embodiment of the present disclosure. In this fourth embodiment, the "best quality" candidate resources are considered without infinite iterations. The process also limits the reporting of less noisy resources by limiting the maximum iterations.

[0084] S R To include the “best quality” candidate resources in,we select only the candidate resources that are below the,RSRP-related threshold from the remaining set,S,. A (1402). The remaining set S A Execute the exclusion step for the inapplicable resources in S (1404) A If the candidate resources in are still less than X% of all resources (1406), then a set of additional resources (i.e., the initial S A -S R ) and perform the legacy exclusion procedure (1408). A If the candidate resource in is still less than X% of all resources (1410), then for a first iteration number N (1414), the threshold associated with the RSRP is increased by an iteration of RSRP increments (1412) to obtain the "third highest quality" candidate resource. If the iteration number is less than N (1414), the process returns to step 1402.

[0085] If the number of iterations is greater than or equal to N (1414) but less than the second number of iterations M (1416), where M is greater than N, then a set of additional resources (i.e., the initial SA -S R ) and perform the legacy exclusion procedure (1408). A Candidate resources in all resources S A If it is greater than X% of (1406, 1410), the remaining S A report (1418) candidate resources in the A Rank the first X% of the candidate resources in by RSRP. If the number of iterations is equal to or greater than the second number of iterations M (1416), rank the remaining S A report (1420) candidate resources in A Rank the first X% of candidate resources in by RSRP. By using multiple maximum iterations, further levels of quality priority can be obtained. Furthermore, by setting the maximum iterations, the "best quality" candidate resources can be considered without infinite iterations, limiting the reporting of less noisy resources. The number of iterations can be set for candidate resources with DRX active time of RX UE and candidate resources with DRX inactive time of RX UE, and the number of iterations between them may be different. The number of iterations for candidate resources with DRX active time of RX UE may be less or more than the number of iterations for candidate resources with DRX inactive time of RX UE.

[0086] 15 shows a flowchart 1500 of a fifth embodiment of the present disclosure. In this fifth embodiment, instead of including a resource in the empty set, S R The resources that are not in the initial set of resources S A The "second highest quality" candidate resource is S R within the range, but above the threshold associated with RSRP.

[0087] In an initialization step 1502, S A All M total To include the "best quality" resources, set S RWe define candidate resources that are not in the initial set S A Exclude from (1504). S A For non-applicable resources (e.g., preempted resources) in the set S, an exclusion step 1506 is performed. A If the candidate resources in are less than X% of the total number of candidate resources (1508), then the threshold associated with the RSRP is iteratively incremented (1510), for example by 3 dB, and the process returns to step 1502 to obtain the “second best quality” candidate resource.

[0088] The remaining S A If the number of candidate resources in is greater than X% of the total number of candidate resources (1508), the remaining S A (1512) and, optionally, the remaining S A Rank the first X% of S by RSRP. R It should be noted that step 1504 of excluding resources that are not within the range can be applied to the PHY approaches of the first to fourth embodiments described herein above. R The candidate resources not in the initial set S A By excluding from S, the subset of resources reported is R become.

[0089] According to the present disclosure, the DRX active time of a RX UE is determined based on the legacy report set S A S R After comparing the candidate resources, they can be prioritized by a two-step or three-step selection performed at the MAC layer. This selection process can be performed in addition to any of the previous embodiments described herein above. Referring to Figure 16, a flowchart 1600 for selecting radio resources for SL communication according to a sixth embodiment of the present disclosure is shown, which includes a two-step selection process performed at the MAC layer.

[0090] In step 1602, S A and S. RSelect a resource at the intersection of . If no resource is selected (1604), R A resource is selected from the non-intersecting resources in (1606). If no resource is selected (1608), A A resource is selected (1610) from among the non-intersecting resources in . When a resource is selected (1604, 1608, 1610), the SL communication transmission is performed (1612) using the selected resource.

[0091] FIG. 17 shows a flowchart 1700 for radio resource selection in SL communication according to a variation of the sixth embodiment of the present disclosure, which includes a three-step selection process performed at the MAC layer.

[0092] In step 1702, S A and S. R If no resource is selected (1704), the resource is selected within an extended timer or by a wake-up signal (WUS). R A resource is selected from the non-intersecting resources in (1706). If no resource is selected (1708), R Select a resource from the remaining non-intersecting resources in (1710). If no resource is selected (1712), A A resource is selected from the remaining non-intersecting resources in (1714). If a resource is selected (1704, 1708, 1712, 1714), the selected resource is used to perform the transmission of the SL communication (1716).

[0093] In the above-mentioned embodiments, the basic reporting and / or selection of candidate resources in SL communication according to the present disclosure is described. However, the present disclosure is not limited to these embodiments. For example, the condition of the maximum number of repetitions in the fourth embodiment of FIG. 14 can be replaced with the maximum RSRP threshold level, or other possible conditions (e.g., CBR, CR). Furthermore, in the second embodiment of FIG. 12, the condition of the maximum number of repetitions can be replaced with the maximum RSRP threshold level, or other possible conditions (e.g., CBR, CR, etc.), and the UE can skip the PHY layer restriction when the maximum number of RSRP increments (or other thresholds) is reached and perform legacy candidate resource selection / reporting.

[0094] In all embodiments, a maximum processing time can be designed (in seconds, symbols, or slots) to allow the UE to skip the PHY layer restrictions and perform legacy selection / reporting of candidate resources. A If the candidate resources in are more than or equal to X% of all resources, the UE skips ranking and selects the remaining S A In addition, for UEs with SL DRX configured, the initial RSRP threshold can be different from the default value when DRX is not configured, or the RSRP increment can be different from the default value when DRX is not configured. For UEs that are aware of the indicated DRX active time of RX UEs, the initial RSRP threshold can be different from the default value when DRX is not configured, or the RSRP increment can be different from the default value when DRX is not configured.

[0095] Also, it should be noted that, although the term "candidate resource" is used throughout the description in this specification, the term "candidate resource" has the same meaning as "resource candidate", "candidate single slot resource", "single slot candidate resource", "single slot resource candidate", "candidate single subframe resource", "single subframe candidate resource", or "single subframe resource candidate".

[0096] Furthermore, in relation to the Release 18 discussion on the coexistence of LTE and NR sidelink on the same carrier, the DRX concept can be reused, where the active time of an RX UE corresponds to slots used exclusively by the NR sidelink, and the inactive time of an RX UE corresponds to slots shared with LTE or slots used only for LTE (or vice versa).

[0097] Furthermore, for NR / LTE slots that are mapped to the active / inactive time of a RX UE, the above-mentioned embodiments can be applied only to NR slots or LTE slots, or as a joint embodiment, for NR / LTE slots that are mapped to the active / inactive time of a RX UE, some embodiments can be applied to NR slots and some (other) embodiments can be applied to LTE slots.

[0098] It can thus be seen that the exemplary embodiments according to the present disclosure provide a communication apparatus and a communication method for reporting and selecting candidate resources in sidelink communication. According to the present disclosure, an optimal solution to resource limitation is provided by categorizing candidate resources with different priorities (e.g., "highest quality", "second highest quality", etc.) for resource reporting to the MAC layer. In determining the priority for including candidate resources, the RSRP threshold increment, the maximum RSRP threshold, and the maximum number of iterations are used to indicate the active time from the RX UE. By applying the solutions and procedures described by the present disclosure, the UE can advantageously select (or have a higher chance of selecting) resources within the indicated active time of the RX UE (and also meet the X% required for reporting to the higher layer).

[0099] The present disclosure can be implemented by software, by hardware, or by software cooperating with hardware. Each functional block used in the description of each embodiment above can be implemented in part or in whole by an LSI such as an integrated circuit, and each process described in each embodiment can be controlled in part or in whole by the same LSI or a combination of LSIs. The LSI can be formed as an integrated circuit chip separately, or a single chip can be formed to include some or all of the functional blocks. The LSI can include a data input / output unit coupled to it. Depending on the degree of integration, the LSI can also be called an integrated circuit (IC), a system LSI, a super LSI, or an ultra LSI. However, the technology for implementing the integrated circuit is not limited to the LSI, and can be implemented by using a dedicated circuit, a general-purpose processor, or a dedicated processor. Furthermore, a field programmable gate array (FPGA) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connections and settings of the circuit cells arranged inside the LSI can also be used. The present disclosure can be implemented as digital processing or analog processing. If, as a result of advances in semiconductor technology or other derivative technologies, LSI is replaced by a future integrated circuit technology, the future integrated circuit technology can be used to integrate the functional blocks. Biotechnology can also be applied.

[0100] The present disclosure may be implemented by any kind of apparatus, device or system having a communication capability (referred to as a communication apparatus).

[0101] A communication device may include a transceiver and processing / control circuitry. The transceiver may include a receiver and a transmitter and / or function as a receiver and a transmitter. The transceiver as a transmitter and a receiver may include a radio frequency (RF) module including an amplifier, an RF modulator / demodulator, etc., and one or more antennas.

[0102] Some non-limiting examples of such communications devices include phones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices), game consoles, e-book readers, telehealth / telemedicine equipment, vehicles providing communications capabilities (e.g., cars, airplanes, ships), and various combinations thereof.

[0103] A communication apparatus is not limited to portable or mobile, but can also include any type of apparatus, device, or system that is non-portable or stationary, such as smart home devices (e.g., appliances, lights, smart meters, control panels), vending machines, and any other "things" in the network of the "Internet of Things" (IoT). Communication includes exchanging data, for example, through cellular systems, wireless LAN systems, satellite systems, and the like, and various combinations thereof.

[0104] A communications device may include devices such as a controller or a sensor coupled to the communications device to perform the communications functions described in this disclosure. For example, a communications device may include a controller or a sensor that generates control or data signals used by the communications device to perform the communications functions of the communications device.

[0105] The communications apparatus may further include infrastructure facilities, such as base stations, access points, and any other apparatus, devices, or systems that communicate with or control apparatuses such as the apparatuses in the non-limiting examples above.

[0106] In this disclosure, the downlink control signal (information) related to this disclosure may be a signal (information) transmitted via a PDCCH of a physical layer, or may be a signal (information) transmitted via a MAC control element (CE) or RRC of a higher layer. The downlink control signal may be a predefined signal (information).

[0107] The uplink control signal (information) related to the present disclosure may be a signal (information) transmitted via a PUCCH of the physical layer, or may be a signal (information) transmitted via a MAC CE or RRC of a higher layer. Furthermore, the uplink control signal may be a predefined signal (information). The uplink control signal may be replaced by uplink control information (UCI), 1st stage sidelink control information (SCI), or 2nd stage SCI.

[0108] In the present disclosure, the base station may be, for example, a Transmission Reception Point (TRP), a cluster head, an access point, a Remote Radio Head (RRH), an eNodeB (eNB), a gNodeB (gNB), a base station (BS), a base transceiver station (BTS), a base unit, or a gateway. Furthermore, in sidelink communication, a terminal may be employed instead of the base station. The base station may be a relay device that relays communication between an upper node and a terminal. The base station may be a roadside unit.

[0109] The present disclosure can be applied to any of the uplink, downlink, and sidelink.

[0110] The present disclosure may be applied to uplink channels, such as, for example, PUSCH, PUCCH, and PRACH, downlink channels, such as PDSCH, PDCCH, and PBCH, and sidelink channels, such as the physical sidelink shared channel (PSSCH), physical sidelink control channel (PSCCH), and physical sidelink broadcast channel (PSBCH).

[0111] The PDCCH, PDSCH, PUSCH, and PUCCH are examples of a downlink control channel, a downlink data channel, an uplink data channel, and an uplink control channel, respectively. The PSCCH and PSSCH are examples of a sidelink control channel and a sidelink data channel, respectively. The PBCH and PSBCH are examples of a broadcast channel, and the PRACH is an example of a random access channel.

[0112] The present disclosure can be applied to both data channels and control channels. The channels in the present disclosure can be replaced with data channels including PDSCH, PUSCH, and PSSCH, and / or control channels including PDCCH, PUCCH, PBCH, PSCCH, and PSBCH.

[0113] In this disclosure, a reference signal is a signal known to both a base station and a mobile station, and each reference signal may be referred to as a Reference Signal (RS) or sometimes a pilot signal. A reference signal may be any of a DMRS, a Channel State Information - Reference Signal (CSI-RS), a Tracking Reference Signal (TRS), a Phase Tracking Reference Signal (PTRS), a Cell-specific Reference Signal (CRS), and a Sounding Reference Signal (SRS).

[0114] In the present disclosure, the time resource unit is not limited to one or a combination of a slot and a symbol, and may be a time resource unit such as a frame, a superframe, a subframe, a slot, a time slot, a subslot, a minislot, or a time resource unit such as a symbol, an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier-Frequency Division Multiplexing Access (SC-FDMA) symbol, or another time resource unit. The number of symbols included in one slot is not limited to the number exemplified in the above embodiment, and may be another number of symbols.

[0115] The present disclosure may be applied to both licensed and unlicensed bands.

[0116] The present disclosure can be applied to any of communication between a base station and a terminal (Uu link communication), communication between terminals (sidelink communication), and communication between a vehicle and some entity (V2X: Vehicle to Everything). The channels in the present disclosure can be replaced with PSCCH, PSSCH, Physical Sidelink Feedback Channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, and PBCH.

[0117] Furthermore, the present disclosure can be applied to any of terrestrial networks and networks other than terrestrial networks (NTN: Non-Terrestrial Network) that use satellites or High Altitude Pseudo Satellites (HAPS). Furthermore, the present disclosure may be applied to networks with large cell sizes and terrestrial networks with large delays compared to the symbol length or slot length, such as ultra-wideband transmission networks.

[0118] An antenna port refers to a logical antenna (antenna group) formed by one or more physical antennas. In other words, an antenna port does not necessarily refer to one physical antenna, but may refer to an array antenna formed by multiple antennas. For example, the number of physical antennas forming an antenna port is not defined, and instead, the smallest unit by which a terminal can transmit a reference signal is defined as an antenna port. An antenna port may also be defined as the smallest unit for multiplication of a precoding vector weighting.

[0119] Although exemplary embodiments have been described in the above detailed description of the present disclosure, it should be understood that a vast number of variations exist. Furthermore, it should be understood that the exemplary embodiments are merely illustrative and are not intended to limit the scope, applicability, operation, or configuration of the present disclosure in any way. Rather, the above detailed description provides those skilled in the art with a convenient road map for implementing the exemplary embodiments, and it should be understood that various changes can be made in the function and arrangement of the STA communication device and / or AP communication device described in the exemplary embodiments without departing from the scope of the present disclosure as defined in the appended claims.

[0120] 1. A method for radio resource selection and reporting for sidelink (SL) communication, comprising: determining, in a transmitting user equipment (UE), a first set of candidate resources from all resources for SL communication, the first set of candidate resources being determined based on at least a reference signal received power (RSRP) of the SL communication and a discontinuous reception (DRX) active time of the receiving UE; reporting a subset of all resources to an upper layer, where the subset of all resources satisfies a condition, and where the subset of all resources includes at least a portion of the first set of candidate resources; A method comprising:

[0121] 2. The method of claim 1, wherein determining the first set of candidate resources includes determining the first set of candidate resources by including resources having an RSRP lower than a threshold associated with the RSRP and having a DRX active time of the receiving UE.

[0122] 3. The method according to claim 2, wherein if the first set of candidate resources does not satisfy the condition, a threshold associated with the RSRP is increased, and a first set of candidate resources is determined by including in the first set of candidate resources resources that have an RSRP lower than the increased threshold and have a DRX active time of the receiving UE corresponding to the timing of the SL communication.

[0123] 4. The method according to 2. or 3., wherein if the first set of candidate resources does not satisfy the condition, the first set of candidate resources is determined by including resources having a DRX active time of the receiving UE.

[0124] 5. Determining a first set of candidate resources Determining whether a DRX active time of the receiving UE is indicated to a physical (PHY) layer of the transmitting UE; determining a selected receiving UE active time resource in response to resource sensing based on the receiving UE's indicated active time when the receiving UE's DRX active time is indicated to a PHY layer of the transmitting UE; determining a first set of candidate resources in response to the selected receiving UE active time resources; Including, 1. The method according to claim 1.

[0125] 6. The method of claim 5, wherein determining the selected receiving UE active time resource includes determining the selected receiving UE active time resource in response to candidate resources within the indicated active time of the receiving UE and within a resource selection window of the transmitting UE.

[0126] 7. Excluding non-applicable resources in the resources including the first set of candidate resources and the additional resources, the non-applicable resources including resources that are not applicable to sidelink communication; and iteratively performing legacy exclusion to exclude further resources in the additional resources based on an increased threshold associated with the RSRP to derive a second set of candidate resources, where the second set of candidate resources includes non-excluded additional resources; By determining a second set of candidate resources from resources including the first set of candidate resources and additional resources when a number of resources in the first set of candidate resources is less than a preset percentage of all resources, where the additional resources include all resources except the selected receiving UE active time resource; Further comprising: the subset of all resources reported in the reporting step includes resources of the first set of candidate resources and the second set of candidate resources that satisfy the condition; 1. The method according to claim 1.

[0127] 8. Determining a first set of candidate resources When a number of radio resources in the first set of candidate resources is equal to or greater than a preset percentage of all resources, excluding inapplicable resources from all resources to obtain a set of non-excluded resources; when the set of non-excluded resources is less than a preset percentage of all resources, iteratively performing legacy exclusion to exclude resources of the additional resources based on an increased threshold related to the RSRP as long as the number of candidate resources in the set of remaining candidate resources is less than a preset percentage of all candidate resources, to derive a second set of candidate resources including the non-excluded additional resources, where the additional resources include all resources except the selected receiving UE active time resource, and the set of remaining candidate resources includes the non-excluded resources from the first set of candidate resources and the second set of candidate resources; Further comprising: When the set of remaining candidate resources is equal to or greater than a preset percentage of all resources, the subset of all resources reported in the reporting step includes resources in the first set of candidate resources and the second set of candidate resources that satisfy the condition; 1. The method according to claim 1.

[0128] 9. The method according to claim 7 or 8, wherein determining the first set of candidate resources further includes determining, from among candidate resources within an indicated active time of the receiving UE and within a resource selection window of the transmitting UE, a first set of candidate resources that are less than the RSRP and less than an increased threshold associated with the RSRP.

[0129] 10. A method according to any one of claims 7 to 9, wherein iteratively performing legacy exclusion includes iteratively performing legacy exclusion to exclude resources in the additional resources based on an increased threshold associated with the RSRP to derive a second set of candidate resources, as long as the number of candidate resources in the set of remaining candidate resources is less than a preset percentage of all candidate resources and the number of iterations is less than a maximum number of iterations.

[0130] 11. The method of claim 10, wherein the maximum number of iterations comprises a preset number of iterations.

[0131] 12. A method according to any one of claims 7 to 9, wherein iteratively performing legacy exclusion includes iteratively performing legacy exclusion to exclude resources in the additional resources based on an increased threshold associated with RSRP to derive a second set of candidate resources including non-excluded additional resources, as long as the number of candidate resources in the set of remaining candidate resources is less than a preset percentage of all candidate resources and the increased threshold is less than a preset maximum RSRP threshold level.

[0132] 14. A method according to any one of claims 7 to 9, wherein iteratively performing legacy exclusion includes iteratively performing legacy exclusion to exclude resources in the additional resources based on an increased threshold associated with the RSRP to derive a second set of candidate resources including non-excluded additional resources, as long as the number of candidate resources in the set of remaining candidate resources is less than a preset percentage of the total candidate resources and the processing time for determining the first set of candidate resources is less than a preset maximum processing time.

[0133] 15. The method of claim 14, wherein the maximum processing time comprises a maximum number selected from the set consisting of a maximum number of seconds, a maximum number of symbols, and a maximum number of slots.

[0134] 16. The method of any one of 1. to 15., wherein reporting a subset of all resources to a higher layer includes reporting the subset of all resources including a ranking corresponding to at least some resources of the subset.

[0135] 17. The method of claim 16, wherein at least some of the resources in the subset consist of a pre-configured percentage of the resources in the reported subset of all resources.

[0136] 18. The method of any one of 1. to 17., wherein reporting the subset of all resources to a higher layer includes reporting the subset of all resources to a medium access control (MAC) layer of the transmitting UE.

[0137] 19. The method of claim 18, further comprising: selecting one or more resources in a subset of all resources to be reported to the MAC layer based on the resources that are in the selected set of recipient UE active time resources.

[0138] 20. The method of claim 19, further comprising: if the subset of all resources reported to the MAC layer does not include a resource that is within the set of selected recipient UE active time resources, selecting one or more resources within the subset of all resources reported to the MAC layer that are not within the set of selected recipient UE active time resources.

[0139] 21. A communications device configured for sidelink (SL) communications, the device comprising: A transceiver; A circuit, the transceiver operating in conjunction with the circuit to perform one or more steps according to any one of claims 1 to 20; An apparatus comprising:

Claims

1. 1. A communication device, the communication device being a transmitting user equipment (UE), the communication device comprising: a transceiver configured, during operation, to perform side link (SL) communications; and a circuit for determining, during operation, a first set of candidate resources from all resources for the SL communication, the first set of candidate resources being determined based on at least a reference signal received power (RSRP) of the SL communication and a discontinuous reception (DRX) active time of a receiving UE; a circuit for reporting a subset of all of the resources to a higher layer, the subset of all of the resources satisfying a condition, the subset of all of the resources including at least a portion of the first set of candidate resources; A communication device comprising:

2. determining the first set of candidate resources includes determining the first set of candidate resources by including resources having an RSRP lower than a threshold associated with an RSRP and having a DRX active time of the receiving UE. The communication device according to claim 1 .

3. if the first set of candidate resources does not satisfy the condition, increasing the threshold related to RSRP and determining the first set of candidate resources by including in the first set of candidate resources resources those resources that have an RSRP lower than the increased threshold and have a DRX active time of the receiving UE that corresponds to a timing of the SL communication. The communication device according to claim 2 .

4. if the first set of candidate resources does not satisfy the condition, the first set of candidate resources is determined by including resources having a DRX active time of the receiving UE; The communication device according to claim 2 or 3.

5. determining the first set of candidate resources Determining whether a DRX active time of the receiving UE is indicated to a physical (PHY) layer of the transmitting UE; determining a selected receiving UE active time resource in response to resource sensing based on the indicated active time of the receiving UE when the DRX active time of the receiving UE is indicated to the PHY layer of the transmitting UE; determining the first set of candidate resources in response to the selected receiving UE active time resources; Including, The communication device according to claim 1 .

6. determining the selected receiving UE active time resource includes determining the selected receiving UE active time resource in response to candidate resources within the indicated active time of the receiving UE and within a resource selection window of the transmitting UE. The communication device according to claim 5.

7. excluding non-applicable resources among resources including the first set of candidate resources and the additional resources, the non-applicable resources including resources that are not applicable to the sidelink communication; and iteratively performing legacy exclusion to exclude further resources in the additional resources based on an increased threshold associated with the RSRP to derive the second set of candidate resources, wherein the second set of candidate resources includes non-excluded additional resources; By determining a second set of candidate resources from resources including the first set of candidate resources and additional resources when a number of resources in the first set of candidate resources is less than a preset percentage of all resources, wherein the additional resources include all resources except a selected receiving UE active time resource; Further comprising: the subset of all resources reported in the reporting step includes resources of the first set of candidate resources and the second set of candidate resources that satisfy the condition. The communication device according to claim 1 .

8. determining the first set of candidate resources When the number of radio resources in the first set of candidate resources is equal to or greater than a preset percentage of all resources, excluding non-applicable resources from all resources to obtain a set of non-excluded resources; when the set of non-excluded resources is less than a preset percentage of all resources, iteratively performing legacy exclusion to exclude resources of additional resources based on an increased threshold related to the RSRP as long as a number of candidate resources in a set of remaining candidate resources is less than a preset percentage of all candidate resources, to derive a second set of candidate resources including non-excluded additional resources, wherein the additional resources include all resources except a selected receiving UE active time resource, and the set of remaining candidate resources includes non-excluded resources from the first set of candidate resources and the second set of candidate resources; Further comprising: When the set of remaining candidate resources is equal to or greater than the preset percentage of all resources, the subset of all resources reported in the reporting step includes resources of the first set of candidate resources and the second set of candidate resources that satisfy the condition. The communication device according to claim 1 .

9. 9. The communications device of claim 7 or 8, wherein determining the first set of candidate resources further comprises determining, from among candidate resources within the indicated active time of the receiving UE and within a resource selection window of the transmitting UE, the first set of candidate resources that are less than the RSRP and less than the increased threshold associated with the RSRP.

10. and iteratively performing legacy exclusion includes iteratively performing legacy exclusion to exclude resources in the additional resources based on an increased threshold associated with the RSRP to derive the second set of candidate resources, as long as a number of candidate resources in the set of remaining candidate resources is less than the preset percentage of total candidate resources and a number of iterations is less than a maximum number of iterations. A communication device according to any one of claims 7 to 9.

11. The communications device of claim 10 , wherein the maximum number of iterations comprises a preset number of iterations.

12. 10. The communication device of claim 7, wherein iteratively performing legacy exclusion comprises iteratively performing legacy exclusion to exclude resources in the set of remaining candidate resources based on an increased threshold associated with the RSRP to derive the second set of candidate resources including non-excluded additional resources, as long as a number of candidate resources in the set of remaining candidate resources is less than the preset percentage of total candidate resources and the increased threshold is less than a preset maximum RSRP threshold level.

13. iteratively performing legacy exclusion includes iteratively performing legacy exclusion to exclude resources in the set of remaining candidate resources based on an increased threshold associated with the RSRP to derive the second set of candidate resources including non-excluded additional resources, as long as a number of candidate resources in the set of remaining candidate resources is less than the preset percentage of total candidate resources and a processing time for determining the first set of candidate resources is less than a preset maximum processing time. A communication device according to any one of claims 7 to 9.

14. 14. The communication device of claim 13, wherein the maximum processing time comprises a maximum number selected from the set consisting of a maximum number of seconds, a maximum number of symbols, and a maximum number of slots.

15. reporting the subset of all the resources to a higher layer includes reporting the subset of all the resources including a ranking corresponding to at least some of the resources of the subset. A communication device according to any one of claims 1 to 14.

16. the at least some resources of the subset consisting of the pre-configured percentage of the resources in the reported subset of all the resources.

16. The communication device of claim 15.

17. reporting the subset of all the resources to a higher layer includes reporting the subset of all the resources to a Medium Access Control (MAC) layer of the transmitting UE. A communication device according to any one of claims 1 to 16.

18. 20. The communications apparatus of claim 17, further comprising: selecting one or more resources in the subset of all resources to be reported to the MAC layer based on resources that are in a selected set of receiving UE active time resources.

19. and if the subset of all resources reported to the MAC layer does not include a resource that is within the set of selected receiving UE active time resources, selecting one or more resources within the subset of all resources reported to the MAC layer that are not within the set of selected receiving UE active time resources.

20. The communication device of claim 18.

20. 1. A method performed by a transmitting user equipment (UE), comprising: performing sidelink (SL) communication; determining a first set of candidate resources from all resources for the SL communication, the first set of candidate resources being determined based on at least a Reference Signal Received Power (RSRP) of the SL communication and a Discontinuous Reception (DRX) active time of a receiving UE; reporting a subset of all the resources to a higher layer, the subset of all the resources satisfying a condition, the subset of all the resources including at least a portion of the first set of candidate resources; A method comprising:

21. 1. An integrated circuit for controlling a process of a transmitting user equipment (UE), said process comprising: performing sidelink (SL) communication; determining a first set of candidate resources from all resources for the SL communication, the first set of candidate resources being determined based on at least a Reference Signal Received Power (RSRP) of the SL communication and a Discontinuous Reception (DRX) active time of a receiving UE; reporting a subset of all the resources to a higher layer, the subset of all the resources satisfying a condition, the subset of all the resources including at least a portion of the first set of candidate resources; Including, Integrated circuits.

22. A communication device, the communication device being a receiving user equipment (UE), the communication device comprising: a transceiver configured, during operation, to perform side link (SL) communications; a receiver for receiving data from a transmitting UE based on a set of candidate resources from all resources for the SL communication during operation, the set of candidate resources being determined based on at least a Reference Signal Received Power (RSRP) of the SL communication and a Discontinuous Reception (DRX) active time of the receiving UE; A communication device comprising:

23. 1. A method performed by a receiving user equipment (UE), comprising: performing sidelink (SL) communication; receiving data from a transmitting UE based on a set of candidate resources from all resources for the SL communication, the set of candidate resources being determined based on at least a reference signal received power (RSRP) of the SL communication and a discontinuous reception (DRX) active time of the receiving UE; A method comprising:

24. 1. An integrated circuit for controlling a process of a receiving user equipment (UE), said process comprising: performing sidelink (SL) communication; receiving data from a transmitting UE based on a set of candidate resources from all resources for the SL communication, the set of candidate resources being determined based on at least a reference signal received power (RSRP) of the SL communication and a discontinuous reception (DRX) active time of the receiving UE; Including, Integrated circuits.

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