Procedure for adjusting the contention window size for sidelink groupcasts

Abstract

An apparatus, method, and system for a contention window size adjustment procedure for a sidelink groupcast is disclosed. The apparatus (500) includes a processor (505) and a memory (510). The processor (505) is configured to transmit a physical shared control channel ("PSCCH") and a physical shared sidelink channel ("PSSCH") corresponding to a groupcast data transmission. The processor (505) is configured to receive a physical shared feedback channel ("PSFCH") including hybrid automatic repeat request ("HARQ") feedback after a predetermined number of slots of the corresponding groupcast transmission. The processor (505) is configured to determine a contention window size adjustment for the groupcast PSSCH based on the transmitted groupcast HARQ feedback associated with the PSSCH within a reference duration.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 249,758, filed September 29, 2021, by Karthikeyan Ganesan et al., entitled “Contention window size adjustment procedure for sidelink groupcast,” which is incorporated herein by reference.

[0002] The subject matter disclosed herein generally relates to wireless communications, and more specifically to a procedure for adjusting the contention window size for sidelink groupcasts. [Background technology]

[0003] In wireless networks, devices may connect directly to each other using a technology called sidelink communication. Sidelink is a communication paradigm that allows cellular devices to communicate their data without relaying it through the network. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP(registered trademark) TS 37.213 [Overview of the project] [Means for solving the problem]

[0005] Apparatus, methods, and systems for contention window resizing procedures for sidelink group casting are disclosed.

[0006] In one embodiment, the first device includes a processor and memory coupled to the processor. In one embodiment, the processor is configured to cause the device to transmit a physical shared control channel ("PSCCH") and a physical shared sidelink channel ("PSSCH") corresponding to group cast data transmissions. In one embodiment, the processor is configured to cause the device to receive a physical shared feedback channel ("PSFCH") containing hybrid automatic retransmission request ("HARQ") feedback after a predetermined number of slots of corresponding group cast transmissions. In one embodiment, the processor is configured to cause the device to determine contention window size adjustments for group cast PSSCHs based on transmitted group cast HARQ feedback related to PSSCHs within a reference duration.

[0007] In one embodiment, the first method transmits PSCCH and PSSCH corresponding to group cast data transmission. In one embodiment, the first method receives a PSFCH including HARQ feedback after a predetermined number of slots of the corresponding group cast transmission. In one embodiment, the first method determines contention window size adjustment for group cast PSSCH based on transmitted group cast HARQ feedback related to PSSCH within a reference duration.

[0008] In one embodiment, the second device includes a processor and memory coupled to the processor. In one embodiment, the processor is configured to cause the device to receive PSCCH and PSSCH corresponding to group cast data transmissions. In one embodiment, the processor is configured to cause the device to transmit a PSFCH including HARQ feedback after a predetermined number of slots of the corresponding group cast transmission in order to determine contention window size adjustment for the group cast PSSCH based on transmitted group cast HARQ feedback related to the PSSCH within a reference duration.

[0009] In one embodiment, the second method receives PSCCH and PSSCH corresponding to group cast data transmissions. In one embodiment, the second method transmits a PSFCH containing HARQ feedback after a predetermined number of slots of the corresponding group cast transmission to determine contention window size adjustment for the group cast PSSCH based on transmitted group cast HARQ feedback related to the PSSCH within a reference duration.

[0010] A more detailed description of the embodiments briefly described above is made by reference to specific embodiments shown in the accompanying drawings. Understanding that these drawings illustrate only a few embodiments and should therefore not be considered limitations of scope, the embodiments are described and explained more specifically and in detail using the accompanying drawings. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic block diagram illustrating one embodiment of a wireless communication system for a contention window resizing procedure for sidelink groupcasting. [Figure 2] This figure shows an example of channel access in the new wireless ("NR")-U. [Figure 3]This diagram shows the relay between user equipment ("UE") and the UE. [Figure 4] This figure shows one embodiment of the NR protocol stack. [Figure 5] This is a block diagram showing one embodiment of a user device that may be used for a contention window resizing procedure for sidelink groupcasting. [Figure 6] This is a schematic block diagram showing one embodiment of a network device that may be used for a contention window resizing procedure for sidelink groupcasting. [Figure 7] This flowchart illustrates one embodiment of a method for adjusting the contention window size for sidelink group casting. [Figure 8] This flowchart illustrates one embodiment of a method for adjusting the contention window size for sidelink group casting. [Modes for carrying out the invention]

[0012] As those skilled in the art will understand, embodiments of the models may be embodied as systems, apparatus, methods, or program products. Accordingly, embodiments may take the form of all hardware embodiments, all software embodiments (including firmware, resident software, microcode, etc.), or embodiments that combine software and hardware embodiments.

[0013] For example, the disclosed embodiments may be implemented as hardware circuits including custom very large-scale integrated circuits ("VLSI") or off-the-shelf semiconductors, transistors, or other discrete components such as gate arrays, logic chips, etc. The disclosed embodiments may also be implemented in programmable hardware devices such as field-programmable gate arrays, programmable array logic, or programmable logic devices. As another example, the disclosed embodiments may include one or more physical or logical blocks of executable code, which may be organized as objects, procedures, or functions, for example.

[0014] Furthermore, embodiments may take the form of a program product embodied in one or more computer-readable storage devices that store machine-readable code, computer-readable code, and / or program code, hereafter referred to as code. The storage device may be tangible, non-transient, and / or non-transmitting. The storage device may not embody signals. In certain embodiments, the storage device employs only signals for accessing the code.

[0015] Any combination of one or more computer-readable media may be used. The computer-readable media may be computer-readable storage media. The computer-readable storage media may be a storage device that stores code. The storage device may be, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination thereof.

[0016] More specific examples of storage devices (a non-exclusive list) include, namely, electrical connections having one or more wires, portable computer diskettes, hard disks, random access memory ("RAM"), read-only memory ("ROM"), erasable programmable read-only memory ("EPROM") or flash memory, portable compact disk read-only memory ("CD-ROM"), optical storage devices, magnetic storage devices, or any suitable combination thereof. In the context of this specification, computer-readable storage media may be any tangible medium that can contain or store programs for use by or in connection with an instruction execution system, apparatus, or device.

[0017] The code for performing the operation of the embodiments may consist of any number of lines and may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Python, Ruby, Java, Smalltalk, and C++, conventional procedural programming languages ​​such as the C programming language, and / or machine language such as assembly language. The code may run entirely on the user's computer, partially on the user's computer as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer via any type of network, including a local area network ("LAN"), a wireless LAN ("WLAN"), or a wide area network ("WAN"), or the connection to the external computer may be (for example, via the Internet using an Internet Service Provider ("ISP")).

[0018] Furthermore, the features, structures, or characteristics described in the embodiments may be combined in any suitable manner. In the following description, numerous specific details, such as examples of programming, software modules, user selection, network transactions, database queries, database structures, hardware modules, hardware circuits, and hardware chips, are provided to allow for a full understanding of the embodiments. However, those skilled in the art will recognize that embodiments may be carried out without one or more of the specific details, or using other methods, components, materials, etc. In other cases, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring the aspects of the embodiments.

[0019] Throughout this specification, any reference to “one embodiment,” “an embodiment,” or similar wording means that a particular feature, structure, or characteristic described in relation to an embodiment is included in at least one embodiment. Thus, throughout this specification, any occurrence of the phrases “in one embodiment,” “in an embodiment,” and similar wording may, but not necessarily, refer to the same embodiment and may mean “one or more, but not all, embodiments” unless otherwise specified. The terms “including,” “comprising,” “having,” and their variations mean “including, but not limited to,” unless otherwise specified. Lists of items do not imply that any or all of the items are mutually exclusive unless otherwise specified. Also, the terms “a,” “an,” and “the” mean “one or more” unless otherwise specified.

[0020] As used herein, lists using the conjunction "and / or" include any single item in the list or any combination of items in the list. For example, the list A, B, and / or C includes A only, B only, C only, a combination of A and B, a combination of B and C, a combination of A and C, or a combination of A, B, and C. As used herein, lists using the term "one or more of" include any single item in the list or any combination of items in the list. For example, one or more of A, B, and C includes A only, B only, C only, a combination of A and B, a combination of B and C, a combination of A and C, or a combination of A, B, and C. As used herein, lists using the term "one of" include exactly one of any single items in the list. For example, "one of A, B, and C" includes A only, B only, or C only, and excludes the combination of A, B, and C. As used herein, “a member selected from the group consisting of A, B, and C” includes only one of A, B, or C, and excludes combinations of A, B, and C. As used herein, “a member selected from the group consisting of A, B, and C and combinations thereof” includes A alone, B alone, C alone, a combination of A and B, a combination of B and C, a combination of A and C, or a combination of A, B, and C.

[0021] Aspects of the embodiments are described below with reference to schematic flowcharts and / or schematic block diagrams of methods, apparatus, systems, and program products according to the embodiments. It will be understood that each block in the schematic flowcharts and / or schematic block diagrams, as well as combinations of blocks in the schematic flowcharts and / or schematic block diagrams, can be implemented by code. This code may be provided to a multipurpose computer, a dedicated computer, or a processor of another programmable data processing device to generate a machine, such that instructions executed by the processor of the computer or other programmable data processing device create means for performing the functions / operations defined in the flowcharts and / or block diagrams.

[0022] The code may be stored in a storage device that can instruct a computer, other programmable data processing device, or other device to function in a particular way so that the instructions stored in the storage device produce a product containing instructions that perform functions / operations defined in flowcharts and / or block diagrams.

[0023] The code may be loaded onto a computer, another programmable device, or another device to perform a series of operational steps on the computer, another programmable device, or another device, so as to provide a process for the code to be executed by the computer to perform the functions / operations defined in the flowchart and / or block diagram.

[0024] Flowcharts and / or block diagrams in drawings illustrate the architecture, function, and operation of possible implementations of devices, systems, methods, and program products in various embodiments. In this regard, each block in a flowchart and / or block diagram may represent a module, segment, or portion of code containing one or more executable instructions of code for implementing a defined logical function.

[0025] It should also be noted that in some alternative implementations, the functions shown in the blocks may be performed in a different order than that shown in the diagram. For example, two blocks shown consecutively may actually be executed substantially simultaneously, or blocks may be executed in reverse order depending on the functions they relate to. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more blocks or parts of the diagram shown.

[0026] Various types of arrows and lines may be used in flowcharts and / or block diagrams, but they are understood not to limit the scope of the corresponding embodiment. In fact, some arrows or other connecting lines may be used only to indicate the logical flow of the shown embodiment. For example, an arrow may indicate an unspecified duration of waiting or monitoring period between enumerated steps of the shown embodiment. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, may be implemented by a system based on dedicated hardware that performs a specified function or operation, or by a combination of dedicated hardware and code.

[0027] The descriptions of elements in each figure may refer to elements in the procedure diagrams. Similar numbers refer to the same elements (including alternative embodiments of similar elements) in all figures.

[0028] In general, this disclosure describes systems, methods, and apparatus for contention window resizing procedures for sidelink groupcasts. In certain embodiments, the method may be performed using computer code embedded in a computer-readable medium. In certain embodiments, the apparatus or system may include a computer-readable medium containing computer-readable code that, when executed by a processor, causes the apparatus or system to perform at least a portion of the solutions described below.

[0029] The Type 1 channel access describing the contention window size adjustment procedure described in 3GPP® TS 37.213 (incorporated herein by reference) is for Uu interfaces and is designed, more specifically, for unicast physical downlink shared channels ("PDSCH"), physical uplink shared channels ("PUSCH"), and transmissions based on transport blocks ("TB") and code block groups ("CBG"). However, such contention window size ("CWS") adjustment procedures may require further consideration of groupcast or multicast traffic, given the different HARQ feedback types for groupcast support, e.g., groupcast HARQ feedback option 1 (common NACK) and groupcast HARQ feedback option 2 (dedicated ACK / NACK) as defined in NR Rel16 Sidelink.

[0030] Figure 1 shows a wireless communication system 100 that supports CSI enhancement for higher frequencies according to embodiments of the present disclosure. In one embodiment, the wireless communication system 100 includes at least one remote unit 105, a radio access network ("RAN") 120, and a mobile core network 130. The RAN 120 and the mobile core network 130 form a mobile communication network. The RAN 120 may consist of a base unit 121 with which the remote unit 105 communicates using a wireless communication link 115. While a specific number of remote units 105, base unit 121, wireless communication link 115, RAN 120, and mobile core network 130 are shown in Figure 1, those skilled in the art should be aware that any number of remote units 105, base unit 121, wireless communication link 115, RAN 120, and mobile core network 130 may be included in the wireless communication system 100.

[0031] In one implementation, RAN 120 conforms to a 5G system as defined in the Third Generation Partnership Project ("3GPP®") specifications. For example, RAN 120 may be a Next Generation Radio Access Network ("NG-RAN") implementing an NR RAT and / or a 3GPP® Long-Term Evolution ("LTE") RAT. In another example, RAN 120 may include a non-3GPP® RAT (e.g., Wi-Fi® or a WLAN compliant with the IEEE 802.11 family). In yet another implementation, RAN 120 conforms to an LTE system as defined in the 3GPP® specifications. However, more broadly, the wireless communication system 100 may implement any other open or proprietary communication network, among other things, such as Worldwide Interoperability for Microwave Access ("WiMAX") or standards of the IEEE 802.16 family. This disclosure is not intended to be limited to any specific wireless communication system architecture or protocol implementation.

[0032] In one embodiment, the remote unit 105 may include computing devices such as desktop computers, laptop computers, personal digital assistants ("PDAs"), tablet computers, smartphones, smart televisions (e.g., Internet-connected televisions), smart home appliances (e.g., Internet-connected home appliances), set-top boxes, game consoles, security systems (including security cameras), in-vehicle computers, and network devices (e.g., routers, switches, modems). In some embodiments, the remote unit 105 includes wearable devices such as smartwatches, fitness bands, and optical head-mounted displays. Furthermore, the remote unit 105 may be referred to as a UE, subscriber unit, mobile phone, mobile station, user, terminal, mobile terminal, fixed terminal, subscriber station, user terminal, wireless transmit / receive unit ("WTRU"), device, or by other terms used in the art. In various embodiments, the remote unit 105 includes a subscriber identity and / or identification module ("SIM") and a mobile device ("ME") that provides mobile terminal functions (e.g., radio transmission, handover, voice coding and decoding, error detection and correction, signaling, and access to the SIM). In certain embodiments, the remote unit 105 may include a terminal device ("TE") and / or be incorporated into a consumer electronics or device (e.g., the computing device described above).

[0033] The remote unit 105 may communicate directly with one or more base units 121 in the RAN 120 via uplink ("UL") and downlink ("DL") communication signals. Furthermore, the UL and DL communication signals may be transmitted over a wireless communication link 123, where the RAN 120 is an intermediate network that provides the remote unit 105 with access to the mobile core network 130.

[0034] In some embodiments, the remote unit 105 communicates with the application server via a network connection to the mobile core network 130. For example, an application 107 within the remote unit 105 (e.g., a web browser, media client, telephone, and / or Voice over Internet Protocol ("VoIP") application) may trigger the remote unit 105 to establish a protocol data unit ("PDU") session (or other data connection) with the mobile core network 130 via the RAN 120. The mobile core network 130 then uses the PDU session to relay traffic between the remote unit 105 and the application server (e.g., a content server 151 in the packet data network 150). The PDU session represents a logical connection between the remote unit 105 and the user plane function ("UPF") 131.

[0035] To establish a PDU session (or PDN connection), the remote unit 105 needs to register with the mobile core network 130 (also referred to as "attaching to the mobile core network" in the context of a fourth-generation ("4G") system). Note that the remote unit 105 may establish one or more PDU sessions (or other data connections) with the mobile core network 130. Thus, the remote unit 105 may have at least one PDU session for communicating with, for example, the packet data network 150 representing the internet. The remote unit 105 may establish additional PDU sessions for communicating with other data networks and / or other communication peers.

[0036] In the context of a 5G system ("5GS"), the term "PDU session" refers to a data connection that provides end-to-end ("E2E") user plane ("UP") connectivity between a remote unit 105 and a specific data network ("DN") via UPF 131. A PDU session supports one or more quality of service ("QoS") flows. In certain embodiments, a one-to-one mapping may exist between QoS flows and QoS profiles such that all packets belonging to a particular QoS flow have the same 5G QoS identifier ("5QI").

[0037] In the context of 4G / LTE systems such as Evolved Packet Systems ("EPS"), a Packet Data Network ("PDN") connection (also called an EPS session) provides an end-to-end (E2E) UP connection between a remote unit and the PDN. The PDN connection procedure establishes a tunnel between the EPS bearer, i.e., the remote unit 105, and a packet gateway ("PGW", not shown) in the mobile core network 130. In certain embodiments, a one-to-one mapping exists between an EPS bearer and a QoS profile such that all packets belonging to a particular EPS bearer have the same QoS class identifier ("QCI").

[0038] The base units 121 may be geographically distributed. In certain embodiments, the base units 121 may be referred to as access terminals, access points, bases, base stations, node B ("NB"), evolved node B (abbreviated as eNodeB or "eNB," also known as Evolved Universal Terrestrial Radio Access Network ("E-UTRAN") node B), 5G / NR node B ("gNB"), home node B, relay node, RAN node, or by any other terminology used in the art. The base units 121 are generally part of a RAN, such as RAN 120, which may include one or more controllers coupled to one or more corresponding base units 121 for communication. These and other elements of a radio access network are not shown but are generally well known to those skilled in the art. The base units 121 connect to the mobile core network 130 via RAN 120.

[0039] The base unit 121 may serve a number of remote units 105 within a serving area, for example, a cell or a sector of a cell, via a wireless communication link 123. The base unit 121 may communicate directly with one or more of the remote units 105 by communication signals. Generally, the base unit 121 transmits DL communication signals to serve the remote units 105 in the time, frequency, and / or spatial domains. Furthermore, the DL communication signals may be transmitted over the wireless communication link 123. The wireless communication link 123 may be any suitable carrier of the licensed or unlicensed radio spectrum. The wireless communication link 123 facilitates communication between one or more of the remote units 105 and / or one or more of the base units 121. Note that during NR-U operation, the base unit 121 and the remote units 105 communicate over the unlicensed radio spectrum.

[0040] In one embodiment, the sidelink 125 connection enables direct communication between two devices in which the base station does not participate in the transmission and reception of data traffic.

[0041] In one embodiment, the mobile core network 130 is a 5GC or evolved packet core ("EPC") which may be coupled to a packet data network 150, such as the Internet and a private data network, among other data networks. The remote unit 105 may be subscribed to the mobile core network 130 or have other accounts. Each mobile core network 130 belongs to a single public land mobile network ("PLMN"). This disclosure is not intended to be limited to any particular wireless communication system architecture or protocol implementation.

[0042] The mobile core network 130 includes several network functions ("NF"). As shown, the mobile core network 130 includes at least one UPF 131. The mobile core network 130 also includes several control plane ("CP") functions, including but not limited to, an Access and Mobility Management Function ("AMF") 133, a Session Management Function ("SMF") 135, a Network Exposure Function ("NEF"), a Policy Control Function ("PCF") 137, a Unified Data Management Function ("UDM"), and a User Data Repository ("UDR"), which serve the RAN 120.

[0043] UPF 131 is responsible for routing and forwarding packets for interconnecting data networks ("DNs") in a 5G architecture, packet inspection, QoS processing, and external PDU sessions. AMF 133 is responsible for terminating NAS signaling, NAS encryption and integrity protection, registration management, connectivity management, mobility management, access authentication and authorization, and security context management. SMF 135 is responsible for session management (i.e., session establishment, modification, and release), IP address allocation and management for remote units (i.e., UEs), DL data notification, and UPF traffic steering configuration for proper traffic routing.

[0044] The Network Efficiency Function (NEF) is responsible for making network data and resources easily accessible to customers and network partners. Service providers may activate new capabilities and expose them through APIs. These APIs allow authorized third-party applications to monitor and configure network behavior for a large number of different subscribers (i.e., connected devices with different applications). PCF 137 is responsible for a unified policy framework, providing policy rules to CP functions, and access / subscribe information for policy decisions in UDRs.

[0045] The UDM is responsible for generating Authentication and Key Agreement ("AKA") credentials, user identification processing, access authorization, and subscriber management. The UDR is a repository of subscriber information and may be used to serve several network functions. For example, the UDR may store subscriber data, policy-related data, and subscriber-related data that is permitted to be exposed to third-party applications. In some embodiments, the UDM resides in the same location as the UDR and is shown as a combined entity "UDM / UDR"139.

[0046] In various embodiments, the mobile core network 130 may also include an authentication server function ("AUSF") (acting as an authentication server), a network repository function ("NRF") (providing registration and discovery of NF services, enabling NFs to identify appropriate services from one another and communicate with each other via an application programming interface ("API")), or other NFs defined for 5GC. In certain embodiments, the mobile core network 130 may also include an authentication, authorization, and accounting ("AAA") server.

[0047] In various embodiments, the mobile core network 130 supports different types of mobile data connections and different types of network slices, with each mobile data connection utilizing a specific network slice. Here, “network slice” refers to a portion of the mobile core network 130 optimized for a particular type of traffic or communication service. Network instances are identified by single-network slice selection assistance information ("S-NSSAI"), while the set of network slices authorized for use by the remote unit 105 is identified by network slice selection assistance information ("NSSAI").

[0048] Here, “NSSAI” refers to a vector value containing one or more S-NSSAI values. In certain embodiments, different network slices may contain separate instances of network functions such as SMF 135 and UPF 131. In some embodiments, different network slices may share some common network functions such as AMF 133. For simplicity of illustration, different network slices are not shown in Figure 1, but their support is assumed. When different network slices are deployed, the mobile core network 130 may include a network slice selection function ("NSSF") responsible for selecting network slice instances to serve the remote unit 105, determining which NSSAIs are allowed, and determining which AMF set is used to serve the remote unit 105.

[0049] While a specific number and type of network functions are depicted in Figure 1, those skilled in the art should recognize that any number and type of network functions may be included in the mobile core network 130. Furthermore, in an LTE variant in which the mobile core network 130 includes an EPC, the shown network functions may be replaced by appropriate EPC entities such as a Mobility Management Entity ("MME"), a Serving Gateway ("SGW"), a PGW, and a Home Subscriber Server ("HSS"). For example, the AMF 133 may be mapped to the MME, the SMF 135 to the control plane portion of the PGW and / or the MME, the UPF 131 to the user plane portions of the SGW and PGW, and the UDM / UDR 139 to the HSS.

[0050] Figure 1 shows the components of the 5G RAN and 5G core network, but the embodiments described apply to other types of communication networks and RATs, including variants of IEEE 802.11, the Global System for Mobile Communications ("GSM," i.e., 2G digital cellular networks), General Purpose Packet Radio Service ("GPRS"), UMTS, variants of LTE, CDMA 2000, Bluetooth, ZigBee, Sigfox, and others.

[0051] In the following description, the term "gNB" is used for base stations, but it can be replaced by any other radio access node, such as a RAN node, eNB, base station ("BS"), access point ("AP"), NR, etc. Furthermore, the operation is described primarily in the context of 5G NR. However, the proposed solutions / methods are equally applicable to other mobile communication systems that support CSI enhancement for higher frequencies.

[0052] As background, in NR-U, channel access for both DL and UL relies on listen before talk ("LBT"). The gNB and / or UE first sense the channel to determine if there is any ongoing communication before any transmission. When the communication channel is a broadband unlicensed carrier, the clear channel assessment ("CCA") procedure relies on detecting the energy levels in multiple subbands of the communication channel, as shown in Figure 2. For LBT in NR-U of Rel. 16, beamforming is not considered, and only omnidirectional LBT is assumed.

[0053] [Table 1]

[0054] In Rel.16 NR-U, regarding CW adjustments for transmission, including PDSCH and PUSCH, • If new HARQ feedback is available for a previous CW update, the feedback from the most recent COT (Community Occupation) to which the new feedback was received will be used. • If the HARQ feedback is ACK, CW is set to CWmin. If the HARQ feedback is NACK (or if the gNB or UE retransmits the TB when there is no feedback within the window defined below), CW is set to min(CW×2 + 1, CWmax). The window starts from the end of the reference duration and has a duration of max(Xms, duration of the send burst from the beginning of the reference duration + 1ms). • If it cannot be guaranteed that there are no other technologies (same conditions as existing specifications for other cases), then X = 5. Otherwise, X = 10. • If no new HARQ feedback is available, CW remains the same. • Note: HARQ feedback includes any implicit methods for determining HARQ feedback.

[0055] With respect to HARQ feedback based on TB within a single LBT subband, CW is reset if at least one "ACK" is received or at least one NDI is toggled for a TB transmitted within the reference duration. Note: HARQ feedback includes any implicit method of determining HARQ feedback.

[0056] Regarding HARQ feedback based on CBGs within a single LBT subband, CW is reset if "ACK" is received for at least 10% of the CBGs within the reference duration, provided all CBGs remain within the LBT subband. CBG TI set to 0 for CWS adjustment purposes is considered an ACK. Note: HARQ feedback includes any implicit methods for determining HARQ feedback.

[0057] Channels without explicit feedback will use the last updated CWS by any channel that has explicit feedback and uses the same CAPC; otherwise, they will use the smallest CWS corresponding to the CAPC.

[0058] For CWS adjustments for LBT subbands when a single contention window is maintained for each LBT subband, CBGs (if any) and TBs that partially or completely overlap with that LBT subband are taken into consideration. If an "ACK" is received for at least 10% of the CBGs or at least one TB within the reference duration, CW is reset. Note: Other procedures for contention window adjustments within LBT subbands are also applicable. The UE may choose to apply only TB-based feedback for CW adjustments.

[0059] Regarding CWS adjustment for DL, when a single contention window is maintained for multiple LBT subbands, CBGs (if any) and TBs that partially or completely overlap with those multiple LBT subbands are taken into consideration. CW is reset if an "ACK" is received for at least 10% of the CBGs or at least one TB within the reference duration. Note: Other procedures for contention window adjustment within LBT subbands are also applicable.

[0060] According to 3GPP® TS 37.213, Contention Window Adjustment Procedure (as incorporated herein by reference), when an eNB / gNB transmits on a channel a transmission including a PDSCH associated with channel access priority class p, the eNB / gNB adjusts the contention window value CW p Maintain CW before step 1 of the procedure described in this section for those transmissions, as described in section 4.1.1. p Adjust.

[0061] When an eNB sends a transmission on a channel that includes a PDSCH associated with channel access priority class p, the eNB sets the contention window value CW p Maintain and use the following steps to transmit CW before step 1 of the procedure described in section 4.1.1. p Adjust. • For any priority class p ∈ {1, 2, 3, 4}, CW p = CW min,p Set it as follows If at least Z = 80% of the HARQ-ACK values ​​corresponding to PDSCH transmissions in reference subframe k are determined to be NACK, then CW transmissions of any priority class p ∈ {1, 2, 3, 4} will be affected. p Increase it to the next highest allowed value and stay in step 2; otherwise, proceed to step 1.

[0062] Reference subframe k is the start subframe of the most recent transmission on the channel made by the eNB, where at least some HARQ-ACK feedback is expected to be available.

[0063] eNB is a CW for any priority class p ∈ {1, 2, 3, 4} based on a given reference subframe k. p Adjust the value only once.

[0064] Regarding the determination of Z, If the transmission of an eNB for which HARQ-ACK feedback is available begins in the second slot of subframe k, the HARQ-ACK value corresponding to the PDSCH transmission in subframe k + 1 is used in addition to the HARQ-ACK value corresponding to the PDSCH transmission in subframe k + 1. • If the HARQ-ACK value corresponds to a PDSCH transmission on an LAA SCell that is assigned by a (E)PDCCH transmitted on the same LAA SCell, If the eNB does not detect HARQ-ACK feedback for a PDSCH transmission, or if the eNB detects a "DTX", "NACK / DTX", or "any" state, it is counted as a NACK. • If the HARQ-ACK value corresponds to a PDSCH transmission on an LAA SCell that is assigned by a (E)PDCCH transmitted on another serving cell, If a HARQ-ACK feedback for a PDSCH transmission is detected by the eNB, the "NACK / DTX" or "any" state is counted as NACK, and the "DTX" state is ignored. If the eNB does not detect HARQ-ACK feedback regarding PDSCH transmission, If the UE is expected to use PUCCH format 1b with channel selection, the "NACK / DTX" state corresponding to "no transmission" as described in sections 10.1.2.2.1, 10.1.3.1, and 10.1.3.2.1 will be counted as NACK, and the "DTX" state corresponding to "no transmission" will be ignored. Otherwise, HARQ-ACKs related to PDSCH transmissions are ignored. • If a PDSCH transmission has two codewords, the HARQ-ACK values ​​for each codeword are considered separately. A bundled HARQ-ACK spanning M subframes is considered as M HARQ-ACK responses.

[0065] If the eNB starts transmitting on a channel a transmission that includes PDCCH / EPDCCH using DCI format 0A / 0B / 4A / 4B and does not include PDSCH associated with channel access priority class p starting from time t0, the eNB shall maintain the contention window value CW p and, prior to step 1 of the procedure described in section 4.1.1 for those transmissions, adjust CW p using the following steps. · For any priority class p ∈ {1, 2, 3, 4}, set CW p = CW min,p · If less than 10% of the UL transport blocks scheduled by the eNB using type 2 channel access procedure (described in section 4.2.1.2) in the time interval from t0 to t0 + T CO are successfully received, increase CW p for any priority class p ∈ {1, 2, 3, 4} to the next higher permitted value, stay at step 2, otherwise proceed to step 1.

[0066] T CO is calculated as described in section 4.2.1.0.3.

[0067] If the gNB transmits on a channel a transmission that includes PDSCH associated with channel access priority class p, the gNB shall maintain the contention window value CW p and, prior to step 1 of the procedure described in section 4.1.1 for those transmissions, adjust CW p using the following steps. · 1) For any priority class p ∈ {1, 2, 3, 4}, set CW p = CW min,p · 2) If HARQ-ACK feedback is available after the last update of CW p , proceed to step 3. Otherwise, if the gNB's transmission after the procedure described in section 4.1.1 does not include retransmissions or CW p ​​From the end of the reference duration corresponding to the earliest DL channel occupation after the last update, to duration T. w If it is sent internally, proceed to step 5; otherwise, proceed to step 4. 3) HARQ-ACK feedback corresponding to the PDSCH within the reference duration of the most recent DL channel occupation for which HARQ-ACK feedback is available is used as follows: a. If at least one HARQ-ACK feedback is an "ACK" for a PDSCH with feedback based on a transport block, or if at least 10% of the HARQ-ACK feedback is an "ACK" for a PDSCH CBG that was at least partially transmitted on a channel with feedback based on a code block group, proceed to step 1; otherwise, proceed to step 4. 4) CW for all priority classes p∈{1,2,3,4} p Increase it to the next highest allowed value. 5) For any priority class p ∈ {1, 2, 3, 4}, CW p Keep it as is and proceed to step 2.

[0068] The reference duration and duration T in the above procedure. w It is defined as follows: The reference duration for a channel occupation initiated by a gNB that includes the transmission of a PDSCH is defined in this section as the duration from the start of the channel occupation to the end of the first slot in which at least one unicast PDSCH is transmitted on all resources allocated for the PDSCH, or to the end of the first transmit burst by the gNB that includes a unicast PDSCH transmitted on all resources allocated for the PDSCH, whichever comes first. If the channel occupation includes a unicast PDSCH but does not include any unicast PDSCH transmitted on all resources allocated for that PDSCH, the duration of the first transmit burst by the gNB within the channel occupation that includes the unicast PDSCH is the reference duration for CWS coordination. T w = max(T A , T B T is + 1ms), and here, B This is the duration of the transmit burst from the beginning of the reference duration, expressed in ms, and if it cannot be guaranteed in the long term (for example, by the level of regulation) that there are no other technologies sharing the channel, then T A = 5ms, otherwise T A = 10ms.

[0069] If a gNB sends a transmit on a channel using a Type 1 channel access procedure associated with channel access priority class p, and the transmit is not associated with an explicit HARQ-ACK feedback by the corresponding UE, then the gNB has used the most recent CW used for any DL transmit on a channel using a Type 1 channel access procedure associated with channel access priority class p prior to step 1 of the procedure described in subsection 4.1.1. p Using CW p Adjust the following: If the corresponding channel access priority class p is not used for any DL transmission on the channel, CW p = CW min,p This is used.

[0070] When a UE sends a transmission using a Type 1 channel access procedure associated with channel access priority class p on a channel, the UE sets the contention window value CW p Maintain and use the following procedure for CW transmissions before step 1 of the procedure described in subsection 4.2.1.1. p Adjust. When a UE receives an UL grant or AUL-DFI, the contention window size for all priority classes is adjusted as follows: · If the NDI value of at least one HARQ process associated with HARQ_ID_ref is toggled, or n ref If at least one HARQ-ACK value among the HARQ processes associated with HARQ_ID_ref received in the earliest AUL-DFI after +3 indicates an ACK, • For any priority class p ∈ {1, 2, 3, 4}, CW p = CW min,p Set it as follows. Otherwise, CW for any priority class p∈{1,2,3,4} p Increase it to the next highest allowed value. • One or more previous transmissions using a Type 1 channel access procedure {T0, ..., T n} exists, N or more subframes have elapsed since the start subframe of the previous transmission, and neither UL grant nor AUL-DFI has been received, and here each transmission T i Regarding this, if contentionWindowSizeTimer > 0, then N = max(contentionWindowSizeTimer, T i If the burst length is (+ 1), and if not, then CW p It will be adjusted as follows: • CW for all priority classes p∈{1,2,3,4} p Increase it to the next highest allowed value. CW pIt will be adjusted once. • If the UE sends a transmit using the Type 1 channel access procedure before N subframes have elapsed from the start of the UL transmit burst before using the Type 1 channel access procedure, and neither a UL grant nor an AUL-DFI is received, CW p It remains unchanged. · UE receives UL grant or AUL-DFI uses one or more previous transmissions {T0, ...,T} before using Type 1 channel access procedure {T0, ...,T} n The feedback indicates that N or more subframes have elapsed since the start subframe of the previous transmission, and neither a UL grant nor an AUL-DFI has been received, and if contentionWindowSizeTimer > 0, then N = max(contentionWindowSizeTimer, T i If the burst length is (+ 1), and if not, then UE is CW p You may recalculate it as follows. UE is CW p Using the Type 1 channel access procedure, n T0 Revert to the value used to send it. UE is CW p Send {T0, ... ,T n The items will be updated sequentially in the order of}. · If the NDI value of at least one HARQ process associated with 'HARQ_ID_ref' is toggled, or n Ti If at least one HARQ-ACK value among the HARQ processes associated with HARQ_ID_ref' received in the earliest AUL-DFI after +3 indicates an ACK, • For any priority class p ∈ {1, 2, 3, 4}, CW p = CW min,p Set it as follows. Otherwise, CW for any priority class p∈{1,2,3,4} p Increase it to the next highest allowed value. If a UE sends a transmit using the Type 1 channel access procedure before N subframes have elapsed from the start of a UL transmit burst before using the Type 1 channel access procedure, and neither a UL grant nor an AUL-DFI is received, CW p It remains unchanged.

[0071] HARQ_ID_ref is the reference subframe n ref This is the HARQ process ID for UL-SCH in [location]. Reference subframe n ref This is determined as follows: • UE is subframe n g When receiving a UL grant or AUL-DFI, subframe n w This is subframe n, where the UE sent UL-SCH using the Type 1 channel access procedure. g - This is the latest subframe, preceding version 3. • The UE starts with subframe n0, then subframes n0, n1, ..., n w If a transmission containing UL-SCH without any gaps is sent in subframe n0, and the UL-SCH in subframe n0 is not PUSCH mode 1 which starts in the second slot of the subframe, then reference subframe n ref This is subframe n0. • UE starts in the second slot of subframe n0, then subframes n0, n1, ..., n w When transmitting a transmission that includes PUSCH mode 1 without any gaps, reference frame n ref These are subframes n0 and n1. • Otherwise, reference subframe n ref is subframe n w That is the case.

[0072] 'HARQ_ID_ref' is the reference subframe n Ti This is the HARQ process ID for UL-SCH in [location]. Reference subframe n TiThis refers to a transmission T using a Type 1 channel access procedure, where N subframes have elapsed and neither a UL grant nor an AUL-DFI has been received. i It is determined as the starting subframe.

[0073] If an AUL-DFI using DCI format 0A is shown to a UE activated for AUL transmission, and transmission mode 2 is configured with respect to the UE for grant-based uplink transmission, then spatial HARQ-ACK bundling is performed by a logical OR operation across multiple codewords relating to HARQ processes not configured for autonomous UL transmission.

[0074] During the ongoing channel access procedure, CW p If the counter N changes, the UE will init Extract the result and apply it to the ongoing channel access procedure.

[0075] The UE uses a Type 1 channel access procedure to access subframes n0, n1, ..., n w-1 If a set of frames is scheduled to send transmissions containing PUSCH without any gaps, and if no transmissions containing PUSCH can be sent in a set of subframes, then CW is available for all priority classes p∈{1,2,3,4}. p You may leave the value as it was originally.

[0076] The UE's reference subframe for the last scheduled transmission is n ref However, if any priority class p ∈ {1, 2, 3, 4} CW p The value of may remain the same as the value for the last scheduled transmission, which included a PUSCH using a Type 1 channel access procedure.

[0077] When a UE sends a transmission using a Type 1 channel access procedure associated with channel access priority class p on a channel, the UE sets the contention window value CWp Maintain them and use the following steps to adjust CW for their transmission before step 1 of the procedure described in subclause 4.2.1.1. p Adjust CW. · 1) For every priority class p ∈ {1, 2, 3, 4}, set CW p = CW min,p . · 2) If HARQ-ACK feedback is available after the last update of CW p , proceed to step 3. Otherwise, if the UE's transmission after the procedure described in subclause 4.2.1.1 does not include retransmission or corresponds to the end of the reference duration of the earliest UL transmission burst after the last update of CW p and is transmitted within the duration T w , proceed to step 5; otherwise, proceed to step 4. · 3) The HARQ-ACK feedback corresponding to the PUSCH within the reference duration of the latest UL transmission burst for which HARQ-ACK feedback is available is used as follows. · a. If at least one HARQ-ACK feedback is "ACK" for a PUSCH using transmission based on a transport block (TB), or at least 10% of the HARQ-ACK feedback is "ACK" for a PUSCH using transmission based on a code block group (CBG), proceed to step 1; otherwise, proceed to step 4. · 4) Increase CW p for every priority class p ∈ {1, 2, 3, 4} to the next higher permitted value. · 5) For every priority class p ∈ {1, 2, 3, 4}, maintain CW p as it is and proceed to step 2.

[0078] The HARQ-ACK feedback, reference duration, and duration T w in the above procedure are defined as follows. HARQ-ACK feedback for PUSCH transmissions is expected to be provided to the UE, either explicitly or implicitly, and implicit HARQ-ACK feedback for contention window adjustment in this subsection is determined as follows, based on the indication of a new transmission or retransmission in the DCI scheduling the PUSCH: • When a new transmission is indicated, an "ACK" is assumed for the corresponding transport block or code block group within PUSCH for TB-based transmissions and CBG-based transmissions, respectively. • If retransmission is indicated for a TB-based transmission, a "NACK" is expected for the corresponding transport block in PUSCH. • When a retransmission is indicated for a transmission based on a CBG, if the bit value of the Code Block Group Transmission Information (CBGTI) field is "0" or "1", then "ACK" or "NACK" is expected for the corresponding CBG in the corresponding PUSCH, respectively. The reference duration for a channel occupation initiated by a UE, including the transmission of a PUSCH, is defined in this subterm as the duration from the start of the channel occupation to the end of the first slot in which at least one unicast PUSCH is transmitted on all resources allocated for the PUSCH, or to the end of the first transmit burst by the gNB, whichever occurs earlier, including a unicast PUSCH transmitted on all resources allocated for the PDSCH. If the channel occupation includes a unicast PDSCH but does not include any unicast PDSCH transmitted on all resources allocated for that PUSCH, the duration of the first transmit burst by the UE in the channel occupation including the PUSCH is the reference duration for CWS adjustment. T w = max(T A , T B T is + 1ms), and here, Bis the duration of the transmission burst from the start of the reference duration expressed in ms, and T A = 5 ms if there is no other technology sharing the channel that can be guaranteed in the long term (e.g., by the level of regulation), and T A = 10 ms otherwise.

[0079] If the UE transmits on the channel using the type 1 channel access procedure related to the channel access priority class p and the transmission is not associated with the explicit or implicit HARQ-ACK feedback described above in this subclause, the UE shall, before step 1 of the procedure described in subclause 4.2.1.1, use the latest CW p used for any UL transmission on the channel using the type 1 channel access procedure related to the channel access priority class p to adjust CW p . If the corresponding channel access priority class p is not for any UL transmission on the channel, CW p = CW min,p [[ID=十六]]is used.

[0080] Generally, the subject matter described herein is directed to sidelink channel access procedures for CWS adjustment of groupcast data transmissions including different SL groupcast HARQ feedback options. · The CWS adjustment for groupcast HARQ feedback option 1 includes that the NACK feedback received from the UEs of the group members within the reference duration is taken into account for the CWS adjustment procedure. · The CWS adjustment for groupcast HARQ feedback option 2 includes that the number of NACK feedbacks received from the UEs of the group members within the reference duration is taken into account for the CWS adjustment procedure. · Various definitions of the reference duration of the PSSCH considering groupcast are proposed.

[0081] In a first embodiment relating to CWS adjustments for Group Cast HARQ Feedback Option 2 (Dedicated ACK / NACK), the decision for CWS adjustments for PSSCH transmissions based on sidelink group casts may be based on a configured / signaled sidelink group cast HARQ Feedback Option 2, and the transmitting ("Tx") UE may be transmitting a PSSCH using sidelink group cast HARQ Feedback Option 2 by transmitting SCI format 2A such that the cast type indicator is set to "01".

[0082] The CWS adjustment procedure for Groupcast HARQ Feedback Option 2 includes several ACK or NACK feedbacks received from UEs of one or more group members within a reference duration, where the reference duration corresponds to the duration of channel occupation initiated by a Tx UE, including the transmission of a Groupcast PSSCH (associated with Groupcast HARQ Feedback Option 2), starting from the start of channel occupation and ending with the end of the first slot in which at least one Groupcast PSSCH (associated with Groupcast HARQ Feedback Option 2) is transmitted over all resources allocated for the Groupcast PSSCH, or ending with the end of the first transmission burst by a Tx UE including a Groupcast PSSCH (associated with Groupcast HARQ Feedback Option 2) transmitted over all resources allocated for the Groupcast PSSCH, whichever occurs earlier. If a channel occupation includes a groupcast PSSCH (related to groupcast HARQ feedback option 2) but does not include any groupcast PSSCH (related to groupcast HARQ feedback option 2) transmitted on the resources allocated for that groupcast PSSCH, the duration of the first transmit burst by the UE in the channel occupation containing the groupcast PSSCH (related to groupcast HARQ feedback option 2) is the reference duration for CWS adjustment.

[0083] Another example of reference duration corresponds to the duration from the start of channel occupation, starting from the start of channel occupation, until at least one PSFCH receive opportunity is expected or received from at least one of several PSFCH receive opportunities on a PSFCH resource (related to groupcast PSSCH) from UEs of one or more group members belonging to the same L2 destination ID, until at least one HARQ-ACK feedback is expected or received.

[0084] In one embodiment, for any channel access priority class p∈{1,2,3,4}, CWp = CWmin,p is set. If a UE receives a PSFCH associated with groupcast HARQ feedback option 2, and at least Z=X% of the HARQ-ACK feedback value is determined to be a "NACK" corresponding to a groupcast PSSCH transmission within the reference duration from at least one PSFCH reception opportunity from several PSFCH reception opportunities in a PSFCH resource corresponding to any identity M_"ID" of the UE that the UE expects to receive a corresponding PSSCH, then the CWS for any priority class is increased to the next highest allowed value or min(CWp×2 + 1, CWmax,p).

[0085] Instead, if at least Z=Y% of the HARQ-ACK feedback value is determined to be an "ACK" corresponding to a groupcast PSSCH transmission within the reference duration corresponding to any identity M_"ID" of the UE that the UE expects to receive the corresponding PSSCH, then CWS is set to CWmin,p (proceed to step 1 as described in the first bulleted item (for example, step 1 as described in TS 37.213)).

[0086] If no HARQ-ACK feedback is detected for a groupcast PSSCH transmission corresponding to any identity M_"ID" of a UE that the UE expects to receive a corresponding PSSCH belonging to the same L2 destination ID, or if the Tx UE detects a "DTX", it is counted as a NACK corresponding to the receiving ("Rx") UE's identity M_"ID". If at least Z=X% of the HARQ-ACK values ​​are determined to be "NACKs" from UEs that are members of one or more groups belonging to the same L2 destination ID, proceed to the steps above.

[0087] The Z=X% and / or Z=Y% values ​​for NACK and / or ACK, respectively, may be configured per resource pool, per UE, per destination group, or per carrier, or they may be fixed values ​​specified in the standard. These values ​​may depend on the number of UEs sending PSFCH feedback corresponding to group cast PSSCH transmissions.

[0088] In a second embodiment relating to CWS adjustments for Group Cast HARQ Feedback Option 1 (Common NACK Feedback Resource), the determination of Contention Window Size (CWS) adjustments for PSSCH transmissions based on Sidelink Group Casts may be based on a configured / signaled Sidelink Group Cast HARQ Feedback Option 1, and if the UE is configured to transmit SCI Format 2B or SCI Format 2A such that the Cast Type Indicator is set to "11", then Sidelink Group Cast HARQ Feedback Option 1 may be configured using one of the following methods:

[0089] In the first implementation form, the CWS coordination procedure for Groupcast HARQ Feedback Option 1 (Common NACK) includes NACK feedback received from group member UEs on a common NACK feedback resource within a reference duration, the reference duration corresponding to the duration of channel occupation initiated by a Tx UE including the transmission of a Groupcast PSSCH (related to Groupcast HARQ Feedback Option 1), starting from the start of channel occupation and ending with the end of the first slot in which at least one Groupcast PSSCH (related to Groupcast HARQ Feedback Option 1) is transmitted on a resource allocated for the Groupcast PSSCH, or ending with the end of the first transmission burst by a Tx UE including a Groupcast PSSCH (related to Groupcast HARQ Feedback Option 1) transmitted on all resources allocated for the Groupcast PSSCH, whichever comes first. If a channel occupation includes a groupcast PSSCH (related to groupcast HARQ feedback option 1) but does not include any groupcast PSSCH (related to groupcast HARQ feedback option 1) transmitted on all resources allocated for that groupcast PSSCH, then the duration of the first transmit burst by the UE within the channel occupation containing the groupcast PSSCH (related to groupcast HARQ feedback option 1) is the reference duration for CWS adjustment.

[0090] In one embodiment, for any channel access priority class p∈{1,2,3,4}, CWp = CWmin,p is set, and when the UE receives a PSFCH associated with groupcast HARQ feedback option 1, and the HARQ-ACK feedback value corresponding to a groupcast PSSCH transmission within the reference duration is determined to be "NACK", the CWS for any priority class is increased to the next highest allowed value or min(CWp×2 + 1, CWmax,p).

[0091] Instead, if the UE receives a PSFCH associated with groupcast HARQ feedback option 1, and the HARQ-ACK feedback value corresponding to the groupcast PSSCH transmission within the reference duration is determined to be "ACK", proceed to the first step above.

[0092] Instead, if no PSFCH is received on a PSFCH reception opportunity related to a PSSCH transmission within the reference duration, it is considered an "ACK" response, and CWS is set to CWmin,p.

[0093] In the second implementation, the measurement of reference signal received power (RSRP) from a PSFCH reception may be used as another metric to determine the CWS adjustment procedure, which may be thresholded based on at least one of the following: the maximum number of Tx UEs that transmit the PSFCH to the Tx UE that initiated channel occupancy within the reference duration (meeting the minimum communication range (MCR) requirements), the target received power parameter Po, and the fractional path-loss compensation parameter α. When the measured RSRP of the received PSFCH exceeds the threshold, the CWS of any priority class is increased to the next permitted value or min(CWp×2 + 1, CWmax,p). When the measured RSRP of the received PSFCH is below the threshold, the CWS is set to CWmin,p.

[0094] In the third implementation form, the CWS coordination procedure for Groupcast HARQ Feedback Option 1 (Common NACK) includes the number of NACK feedbacks received from the group member UEs within the reference duration, where the reference duration corresponds to the duration from the start of channel occupation initiated by a Tx UE, including the transmission of a PSSCH, until at least HARQ-ACK feedback is expected from PSFCH receptions in several slots where at least one Groupcast PSSCH (related to Groupcast HARQ Feedback Option 1) is transmitted on all resources allocated for the Groupcast PSSCH. Another example of the reference duration corresponds to the duration from the start of channel occupation initiated by a Tx UE, including the transmission of a Groupcast PSSCH (related to Groupcast HARQ Feedback Option 1), until at least HARQ-ACK feedback is expected from at least one PSFCH reception opportunity among several PSFCH reception opportunities in the PSFCH resources related to the Groupcast PSSCH.

[0095] In one embodiment, for any channel access priority class p∈{1,2,3,4}, CWp = CWmin,p is set, and when the UE receives a PSFCH associated with groupcast HARQ feedback option 1, and at least Z = X% of the HARQ-ACK feedback values ​​(for example, the count includes one HARQ-ACK feedback value for each PSFCH reception opportunity) are determined to be a "NACK" corresponding to a groupcast PSFCH transmission within the reference duration, or the RSRP threshold for the received PSFCH exceeds a predefined value for X% of the PSFCH reception opportunities, the CWS for any priority class is increased to the next highest permitted value or min(CWp×2 + 1, CWmax,p).

[0096] Instead, if no PSFCH is received on a PSFCH reception opportunity related to a PSSCH transmission within the reference duration, it is considered an "ACK" response, and CWS is set to CWmin,p if at least Z = Y% of the HARQ-ACK feedback value is determined to be an "ACK" corresponding to a groupcast PSSCH transmission within the reference duration, or if the RSRP threshold for the received PSFCH is less than a predefined value with respect to Y% of the PSFCH reception opportunities. (Proceed to step 1 as described in the first bulleted item (e.g., step 1 as described in TS 37.213)). The values ​​of Z=X% and / or Z=Y% may be configured per resource pool, per UE, per destination group, per carrier, or may be fixed values ​​specified in the standard.

[0097] In a third embodiment relating to blind retransmission and / or mixed retransmission including both HARQ-based retransmission and blind retransmission, if the channel occupation includes PSSCH transmissions based on unicast or groupcast but does not include any HARQ-feedback enabled PSSCHs transmitted on all resources allocated for PSSCHs (for example, the HARQ enable bit in the sidelink control information ("SCI") is not set to "enable"), the duration of the first transmit burst by the UE in the channel occupation transmitted with HARQ-feedback PSSCH enabled is the reference duration for CWS adjustment.

[0098] For example, when a Tx UE decides to transmit a transport block ("TB") using blind retransmission within an occupied channel, the CWS adjustment remains the same. In another example, when a Tx UE decides to transmit a TB using a mixture of blind retransmission and HARQ feedback-enabled transmits, the reference duration (and therefore the CWS) is set according to the first HARQ feedback-enabled PSSCH transmit within the reference duration.

[0099] In one embodiment, when only broadcast-based PSSCHs are transmitted during the reference duration, the CWS adjustment for broadcasts is always set to the same duration. However, the duration of the first transmit burst by a UE within the channel occupancy that is enabled and transmitted with HARQ feedback PSSCH is the reference duration for all cast-type CWS adjustments.

[0100] In the fourth embodiment, which deals with UE-UE relay, the terms eNB / gNB are used for base stations but are replaceable by any other radio access nodes, such as BS, eNB, gNB, AP, NR, etc. Furthermore, the proposed method is described primarily in the context of 5G NR. However, the proposed solution / method is equally applicable to other mobile communication systems that support serving cells / carriers configured for sidelink communication via the PC5 interface.

[0101] In this specification, the following terms are used:

[0102] UE-Network relay: N relay

[0103] UE-UE relay: UE relay

[0104] Relay = Either of the above relays

[0105] Tx Remote UE (UE1) 302 is a UE that has some application data to be sent via Repeater (UE2) 304 to another remote UE, shown as Rx Remote UE (UE3) 306 in Figure 3. At different points in time, UE3 306 may have data to send to UE1 302 via UE2 304, in which case UE3 306 acts as the transmitting UE. The terms and roles shown in Figure 3 are relevant only to specific data packets.

[0106] In a fourth embodiment, the relay UE 304 may have multiple unicast connections using a first interface with one or more UE1 302 (Tx remote UEs) and a second interface with one or more Rx remote UEs. The determination of the contention window sizing procedure for the relay UE (UE2 304 in Figure 3) may depend on HARQ feedback received from one or more Rx remote UEs at the second interface by reusing the procedures described in the first and second embodiments, but those same procedures may also be equally applicable to unicast PSSCH transmissions occurring at the second interface with one or more Rx remote UEs. These Rx remote UEs are not necessarily part of the same destination ID, as described in the first and second embodiments. The transport block may have multiplexed data for multiple Rx remote UEs, and in one example, the determination of the contention window sizing depends on HARQ feedback received from one or more Rx remote UEs belonging within the reference duration.

[0107] In another embodiment, a Tx remote UE may have connections with multiple relay UEs to transmit the same or different TBs belonging to the same destination ID. In such cases, determining the contention window size depends on HARQ feedback received from one or more relay UEs configured to transmit data toward the same destination, as described in the first and second embodiments, for all cast types.

[0108] Figure 4 shows an NR protocol stack 400 according to an embodiment of the present disclosure. Figure 4 shows a remote unit 105, a base unit 121, and a mobile core network 130, which represent the interaction of a set of UEs with RAN nodes and NFs (e.g., AMFs) within the core network. As shown, the protocol stack 400 includes a user plane protocol stack 405 and a control plane protocol stack 410. The user plane protocol stack 405 includes a physical ("PHY") layer 415, a medium access control ("MAC") sublayer 420, a radio link control ("RLC") sublayer 425, a packet data convergence protocol ("PDCP") sublayer 430, and a service data adaptation protocol ("SDAP") layer 435. The control plane protocol stack 410 also includes a physical layer 415, a MAC sublayer 420, an RLC sublayer 425, and a PDCP sublayer 430. The control plane protocol stack 410 also includes the Radio Resource Control ("RRC") sublayer 440 and the Non-Access Layer ("NAS") layer 445.

[0109] The AS protocol stack of the control plane protocol stack 410 consists of at least the RRC, PDCP, RLC, and MAC sublayers, as well as the physical layer. The AS protocol stack of the user plane protocol stack 405 consists of at least the SDAP, PDCP, RLC, and MAC sublayers, as well as the physical layer. Layer 2 ("L2") is divided into the SDAP, PDCP, RLC, and MAC sublayers. Layer 3 ("L3") includes the RRC sublayer 440 and NAS layer 445 of the control plane, and, for example, the Internet Protocol ("IP") layer or PDU layer (not shown) of the user plane. L1 and L2 are referred to as "lower layers," such as PUCCH / PUSCH or MAC CE, while L3 and above (e.g., transport layer, application layer) are referred to as "higher layers" or "upper layers," such as RRC.

[0110] The physical layer 415 provides a transport channel to the MAC sublayer 420. The MAC sublayer 420 provides a logical channel to the RLC sublayer 425. The RLC sublayer 425 provides an RLC channel to the PDCP sublayer 430. The PDCP sublayer 430 provides radio bearers to the SDAP sublayer 435 and / or the RRC layer 440. The SDAP sublayer 435 provides QoS flows to the mobile core network 130 (e.g., 5GC). The RRC layer 440 provides carrier aggregation and / or dual connectivity addition, modification, and release. The RRC layer 440 also manages the establishment, configuration, maintenance, and release of signaling radio bearers ("SRBs") and data radio bearers ("DRBs"). In certain embodiments, RRC entities function for radio link failure detection and recovery from radio link failures.

[0111] Figure 5 shows a user device 500 that may be used for a contention window resizing procedure for sidelink group casting according to embodiments of the present disclosure. In various embodiments, the user device 500 is used to implement one or more of the solutions described above. The user device 500 may be an embodiment of the UE, such as the remote unit 105 and / or UE 205 described above. Furthermore, the user device 500 may include a processor 505, memory 510, input device 515, output device 520, and transceiver 525. In some embodiments, the input device 515 and output device 520 are combined into a single device, such as a touchscreen. In certain embodiments, the user device 500 may not include any input device 515 and / or output device 520. In various embodiments, the user device 500 may include one or more of the processor 505, memory 510, and transceiver 525, and may not include the input device 515 and / or output device 520.

[0112] As shown, the transceiver 525 includes at least one transmitter 530 and at least one receiver 535, where the transceiver 525 communicates with one or more base units 121. In addition, the transceiver 525 may support at least one network interface 540 and / or application interface 545. The application interface 545 may support one or more APIs. The network interface 540 may support 3GPP® reference points such as Uu and PC5. Other network interfaces 540 may be supported, as will be understood by those skilled in the art.

[0113] In one embodiment, the processor 505 may include any known controller capable of executing computer-readable instructions and / or logical operations. For example, the processor 505 may be a microcontroller, microprocessor, central processing unit ("CPU"), graphics processing unit ("GPU"), auxiliary processing unit, field-programmable gate array ("FPGA"), digital signal processor ("DSP"), coprocessor, application-specific processor, or similar programmable controller. In some embodiments, the processor 505 executes instructions stored in memory 510 to perform the methods and routines described herein. The processor 505 is coupled to memory 510, input device 515, output device 520, and transceiver 525 for communication. In certain embodiments, the processor 505 may include an application processor (also known as the "main processor") that manages application domain and operating system ("OS") functions, and a baseband processor (also known as the "baseband radio processor") that manages radio functions.

[0114] In one embodiment, memory 510 is a computer-readable storage medium. In some embodiments, memory 510 includes a volatile computer storage medium. For example, memory 510 may include RAM including dynamic RAM ("DRAM"), synchronous dynamic RAM ("SDRAM"), and / or static RAM ("SRAM"). In some embodiments, memory 510 includes a non-volatile computer storage medium. For example, memory 510 may include a hard disk drive, flash memory, or any other suitable non-volatile computer storage device. In some embodiments, memory 510 includes both a volatile computer storage medium and a non-volatile computer storage medium.

[0115] In some embodiments, memory 510 stores data related to CSI enhancements for higher frequencies. For example, memory 510 may store the parameters, configurations, resource allocations, policies, etc. In certain embodiments, memory 510 also stores program code and related data, such as an operating system or other controller algorithms running on the user equipment device 500, and one or more software applications.

[0116] In one embodiment, the input device 515 may include any known computer input device, such as a touch panel, buttons, a keyboard, a stylus, or a microphone. In some embodiments, the input device 515 may be integrated with the output device 520, for example, as a touchscreen or similar touch display. In some embodiments, the input device 515 includes a touchscreen so that text may be entered using a virtual keyboard displayed on the touchscreen and / or by handwriting on the touchscreen. In some embodiments, the input device 515 includes two or more different devices, such as a keyboard and a touch panel.

[0117] In one embodiment, the output device 520 is designed to output visual, auditory, and / or tactile signals. In some embodiments, the output device 520 includes an electronically controllable display or display device that can output visual data to the user. For example, the output device 520 may include, but is not limited to, an LCD display, LED display, OLED display, projector, or similar display device that can output images, text, etc., to the user. In another non-limiting example, the output device 520 may include a wearable display that is separate from the rest of the user equipment device 500 but coupled to communicate with them, such as a smartwatch, smart glasses, or head-up display. Furthermore, the output device 520 may be a component of a smartphone, personal digital assistant, television, table computer, notebook (laptop) computer, personal computer, or vehicle dashboard.

[0118] In certain embodiments, the output device 520 includes one or more speakers for generating sound. For example, the output device 520 may generate an audible alert or notification (e.g., a beep or chime). In some embodiments, the output device 520 includes one or more haptic devices for generating vibration, motion, or other tactile feedback. In some embodiments, all or part of the output device 520 may be integrated with the input device 515. For example, the input device 515 and the output device 520 may form a touchscreen or similar touch display. In other embodiments, the output device 520 may be located near the input device 515.

[0119] The transceiver 525 includes at least one transmitter 530 and at least one receiver 535. The transceiver 525 may be used to provide UL communication signals to the base unit 121 and to receive DL communication signals from the base unit 121, as described herein. Similarly, the transceiver 525 may be used to send and receive SL signals (e.g., V2X communication), as described herein. Although only one transmitter 530 and one receiver 535 are shown, the user equipment 500 may have any suitable number of transmitters 530 and receivers 535. Furthermore, the transmitters 530 and receivers 535 may be any suitable type of transmitter and receiver. In one embodiment, the transceiver 525 includes a first transmitter / receiver pair used to communicate with a mobile communication network over a licensed radio spectrum and a second transmitter / receiver pair used to communicate with a mobile communication network over an unlicensed radio spectrum.

[0120] In certain embodiments, a first transmitter / receiver pair used to communicate with a mobile communications network over a licensed radio spectrum, and a second transmitter / receiver pair used to communicate with a mobile communications network over an unlicensed radio spectrum, may be combined into a single transceiver unit, for example, a single chip that performs functions for use in both licensed and unlicensed radio spectra. In some embodiments, the first transmitter / receiver pair and the second transmitter / receiver pair may share one or more hardware components. For example, a particular transceiver 525, transmitter 530, and receiver 535 may be implemented as physically separate components that access shared hardware and / or software resources, such as a network interface 540.

[0121] In various embodiments, one or more transmitters 530 and / or one or more receivers 535 may be implemented and / or integrated into a single hardware component such as a multi-transceiver chip, system-on-chip, ASIC, or other type of hardware component. In certain embodiments, one or more transmitters 530 and / or one or more receivers 535 may be implemented and / or integrated into a multi-chip module. In some embodiments, other components such as a network interface 540 or other hardware components / circuits may be integrated into a single chip together with any number of transmitters 530 and / or receivers 535. In such embodiments, the transmitters 530 and receivers 535 may be logically configured as transceivers 525 using one or more common control signals, or as modular transmitters 530 and receivers 535 implemented within the same hardware chip or multi-chip module.

[0122] In one embodiment, the processor 505 transmits PSCCH and PSSCH corresponding to group cast data transmission. In one embodiment, the processor 505 receives a PSFCH including HARQ feedback after a predetermined number of slots of the corresponding group cast transmission. In one embodiment, the processor 505 determines contention window size adjustment for group cast PSSCH based on the transmitted group cast HARQ feedback related to the PSSCH within the reference duration.

[0123] In one embodiment, the processor 505 determines the contention window size adjustment for a device transmitting a group cast PSSCH using the HARQ feedback option 2, based on the percentage of ACK / NACK HARQ feedback received from UEs that are members of one or more groups belonging to the same L2 destination ID.

[0124] In one embodiment, the processor 505 determines the contention window size of the priority class based on at least Z=X% of HARQ-ACK values ​​determined to be "NACK" from UEs of one or more group members belonging to the same destination ID within the reference duration, by the next highest allowed value or a calculated value min(CW×2 + 1, CW max Set it to ), where CW is the contention window size.

[0125] In one embodiment, the processor 505 sets the contention window size of the priority class to a minimum based on at least Z=Y% of HARQ-ACK values ​​determined to be "ACK" from UEs of one or more groups belonging to the same destination ID within the reference duration.

[0126] In one embodiment, failing to detect a PSFCH reception opportunity related to a PSSCH transmission within the reference duration indicates a "NACK" response.

[0127] In one embodiment, the processor 505 detects that there is no PSFCH reception opportunity for a PSSCH transmission within the reference duration and sets the contention window size to CW min,p Set to this.

[0128] In one embodiment, the Z=X% and / or Z=Y% values ​​for NACK and / or ACK, respectively, can be configured per resource pool, per UE, per destination group or carrier, or in any combination thereof, or they are fixed values.

[0129] In one embodiment, the processor 505 determines the contention window size adjustment for a transmitting UE that sends a group cast PSSCH using HARQ feedback option 1, based on a count of the number of NACKs received, or based on the absence of PSFCH feedback from multiple PSFCH opportunities corresponding to a group cast PSSCH.

[0130] In one embodiment, the reference duration corresponds to the duration of channel occupation initiated by the transmitting UE, starting from the start of channel occupation and ending at the end of the first slot in which at least one groupcast PSSCH is transmitted on the resource allocated for the groupcast PSSCH, or ending at the end of the first transmit burst by the transmitting UE containing the groupcast PSSCH transmitted on the resource allocated for the groupcast PSSCH.

[0131] In one embodiment, the processor 505 sets the contention window size of the priority class to the next highest allowed value or a calculated value min(CW × 2 + 1, CW) based on the number of NACKs received from multiple PSFCH opportunities corresponding to group cast PSFCHs that exceed a predetermined value with respect to X% of PSFCH reception opportunities. max Set it to ), where CW is the contention window size.

[0132] In one embodiment, the processor 505 detects that there is no PSFCH reception for multiple PSFCH reception opportunities related to PSSCH transmission within the reference duration, and sets the contention window size to CW min,p Set to this.

[0133] In one embodiment, the reference duration corresponds to the duration of channel occupation initiated by the transmitting UE, starting from the start of channel occupation and continuing until at least one PSFCH receive opportunity is expected from at least one of several PSFCH receive opportunities in a PSFCH resource from a UE belonging to one or more groups of members of the same L2 destination ID.

[0134] In one embodiment, the processor 505 maintains a constant contention window size adjustment in response to transmissions of transport blocks by a transmitting UE using blind retransmissions, broadcasts, HARQ-disabled transmissions, or any combination thereof within an occupied channel.

[0135] In one embodiment, the processor 505 sets the reference duration according to the first HARQ feedback-enabled PSSCH transmit within the reference duration, in response to a transmit UE transmitting a transport block using a mixture of blind retransmission and HARQ feedback-enabled transmit.

[0136] Figure 6 shows one embodiment of a network device 600 that may be used for a contention window resizing procedure for sidelink groupcast according to embodiments of the present disclosure. In some embodiments, the network device 600 may be one embodiment of a RAN node such as the base unit 121 and / or gNB and its supporting hardware described above. Furthermore, the network device 600 may include a processor 605, memory 610, input device 615, output device 620, and transceiver 625. In certain embodiments, the network device 600 does not include any input device 615 and / or output device 620.

[0137] As shown, the transceiver 625 includes at least one transmitter 630 and at least one receiver 635, where the transceiver 625 communicates with one or more remote units 105. In addition, the transceiver 625 may support at least one network interface 640 and / or application interface 645. The application interface 645 may support one or more APIs. The network interface 640 may support 3GPP® reference points such as Uu, N1, N2, N3, N5, N6, and / or N7 interfaces. Other network interfaces 640 may be supported, as will be understood by those skilled in the art.

[0138] When implementing NEF, the network interface 640 may include an interface for communicating with application functions (i.e., N5) and for communicating with at least one network function (e.g., UDR, SFC function, UPF) within a mobile communication network such as the mobile core network 130.

[0139] In one embodiment, the processor 605 may include any known controller capable of executing computer-readable instructions and / or logical operations. For example, the processor 605 may be a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, DSP, coprocessor, application-specific processor, or similar programmable controller. In some embodiments, the processor 605 executes instructions stored in memory 610 to perform the methods and routines described herein. The processor 605 is coupled to the memory 610, input device 615, output device 620, and transceiver 625 for communication. In certain embodiments, the processor 605 may include an application processor (also known as the “main processor”) that manages application domain and OS functions, and a baseband processor (also known as the “baseband radio processor”) that manages radio functions. In various embodiments, the processor 605 controls the network device 600 to perform the behavior of the network entities described above (e.g., gNB) for contention window resizing procedures for sidelink groupcasts.

[0140] In one embodiment, memory 610 is a computer-readable storage medium. In some embodiments, memory 610 includes a volatile computer storage medium. For example, memory 610 may include RAM, including DRAM, SDRAM, and / or SRAM. In some embodiments, memory 610 includes a non-volatile computer storage medium. For example, memory 610 may include a hard disk drive, flash memory, or any other suitable non-volatile computer storage device. In some embodiments, memory 610 includes both a volatile computer storage medium and a non-volatile computer storage medium.

[0141] In some embodiments, memory 610 stores data related to CSI enhancements for higher frequencies. For example, memory 610 may store the parameters, configurations, resource allocations, policies, etc. In certain embodiments, memory 610 also stores program code and related data, such as an OS or other controller algorithm running on the network device 600, and one or more software applications.

[0142] In one embodiment, the input device 615 may include any known computer input device, such as a touch panel, buttons, a keyboard, a stylus, or a microphone. In some embodiments, the input device 615 may be integrated with the output device 620, for example, as a touchscreen or similar touch display. In some embodiments, the input device 615 includes a touchscreen so that text may be entered using a virtual keyboard displayed on the touchscreen and / or by handwriting on the touchscreen. In some embodiments, the input device 615 includes two or more different devices, such as a keyboard and a touch panel.

[0143] In one embodiment, the output device 620 may include any known electronically controllable display or display device. The output device 620 may be designed to output visual, auditory, and / or tactile signals. In some embodiments, the output device 620 includes an electronic display that can output visual data to a user. Furthermore, the output device 620 may be a component of a smartphone, personal digital assistant, television, table computer, notebook (laptop) computer, personal computer, or vehicle dashboard.

[0144] In certain embodiments, the output device 620 includes one or more speakers for generating sound. For example, the output device 620 may generate an audible alert or notification (e.g., a beep or chime). In some embodiments, the output device 620 includes one or more haptic devices for generating vibration, motion, or other tactile feedback. In some embodiments, all or part of the output device 620 may be integrated with the input device 615. For example, the input device 615 and the output device 620 may form a touchscreen or similar touch display. In other embodiments, all or part of the output device 620 may be located near the input device 615.

[0145] As described above, transceiver 625 may communicate with one or more remote units and / or one or more interconnection functions that provide access to one or more PLMNs. Transceiver 625 may also communicate with one or more network functions (for example, within the mobile core network 130). Transceiver 625 operates under the control of processor 605 to transmit and receive messages, data, and other signals. For example, processor 605 may selectively activate transceivers (or parts thereof) at specific times to send and receive messages.

[0146] The transceiver 625 may include one or more transmitters 630 and one or more receivers 635. In certain embodiments, one or more transmitters 630 and / or one or more receivers 635 may share transceiver hardware and / or circuitry. For example, one or more transmitters 630 and / or one or more receivers 635 may share antennas, antenna tuners, amplifiers, filters, oscillators, mixers, modulators / demodulators, power supplies, etc. In one embodiment, the transceiver 625 implements multiple logical transceivers using different communication protocols or protocol stacks while using common physical hardware.

[0147] In one embodiment, the processor 605 transmits PSCCH and PSSCH corresponding to group cast data transmissions. In one embodiment, the processor 605 transmits a PSFCH including HARQ feedback after a predetermined number of slots of the corresponding group cast transmission to determine contention window size adjustment for the group cast PSSCH based on transmitted group cast HARQ feedback related to the PSSCH within the reference duration.

[0148] Figure 7 is a flowchart of Method 700 for a contention window resizing procedure for sidelink group casting. Method 700 may be performed by a UE as described herein, for example, a remote unit 105 and / or user equipment device 500. In some embodiments, Method 700 may be performed by a processor that executes program code, for example, a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0149] In one embodiment, method 700 starts and transmits PSCCH and PSSCH corresponding to group cast data transmission (705). In one embodiment, method 700 receives a PSFCH containing HARQ feedback after a predetermined number of slots of corresponding group cast transmissions (710). In one embodiment, method 700 determines a contention window size adjustment for group cast PSSCH based on transmitted group cast HARQ feedback related to PSSCH within a reference duration (715), and method 700 terminates.

[0150] Figure 8 is a flowchart of Method 800 for a contention window resizing procedure for sidelink groupcast. Method 800 may be performed by network devices described herein, such as the base unit 121, gNB, and / or network equipment device 600. In some embodiments, Method 800 may be performed by a processor that executes program code, such as a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0151] In one embodiment, method 800 starts and receives PSCCH and PSSCH corresponding to group cast data transmissions (805). In one embodiment, method 800 transmits a PSFCH containing HARQ feedback after a predetermined number of slots of corresponding group cast transmissions to determine contention window size adjustment for group cast PSSCH based on transmitted group cast HARQ feedback related to PSSCH within a reference duration (810), and method 800 terminates.

[0152] A first apparatus for a contention window resizing procedure for sidelink group casting is disclosed. The first apparatus may include UEs described herein, such as remote unit 105 and / or user equipment apparatus 500. In some embodiments, the first apparatus includes a processor that executes program code, such as a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0153] In one embodiment, the first device includes a processor and memory coupled to the processor. In one embodiment, the processor is configured to cause the device to transmit PSCCH and PSSCH corresponding to group cast data transmissions. In one embodiment, the processor is configured to cause the device to receive a PSFCH including HARQ feedback after a predetermined number of slots of corresponding group cast transmissions. In one embodiment, the processor is configured to cause the device to determine contention window size adjustment for group cast PSSCH based on transmitted group cast HARQ feedback related to PSSCH within a reference duration.

[0154] In one embodiment, the processor is configured to determine the contention window size adjustment for a device transmitting a group cast PSSCH using HARQ feedback option 2, based on the percentage of ACK / NACK HARQ feedback received from UEs that are members of one or more groups belonging to the same L2 destination ID.

[0155] In one embodiment, the processor determines the contention window size of the priority class based on at least Z=X% of HARQ-ACK values ​​determined to be "NACK" from UEs of one or more groups belonging to the same destination ID within the reference duration, by the next highest allowed value or a calculated value min(CW×2 + 1, CW maxIt is configured to be set to ), where CW is the contention window size.

[0156] In one embodiment, the processor is configured to set the contention window size of the priority class to a minimum depending on at least Z=Y% of HARQ-ACK values ​​that have been determined to be "ACKs" from UEs of one or more groups belonging to the same destination ID within the reference duration.

[0157] In one embodiment, failing to detect a PSFCH reception opportunity related to a PSSCH transmission within the reference duration indicates a "NACK" response.

[0158] In one embodiment, the processor, upon detecting that there is no PSFCH reception opportunity for a PSSCH transmission within the reference duration, sets the contention window size to CW min,p It is configured to be set to [this value].

[0159] In one embodiment, the Z=X% and / or Z=Y% values ​​for NACK and / or ACK, respectively, can be configured per resource pool, per UE, per destination group or carrier, or in any combination thereof, or they are fixed values.

[0160] In one embodiment, the processor is configured to determine the contention window size adjustment for a transmitting UE that sends a group cast PSSCH using HARQ feedback option 1, based on a count of the number of NACKs received, or based on the absence of PSFCH feedback from multiple PSFCH opportunities corresponding to a group cast PSSCH.

[0161] In one embodiment, the reference duration corresponds to the duration of channel occupation initiated by the transmitting UE, starting from the start of channel occupation and ending at the end of the first slot in which at least one groupcast PSSCH is transmitted on the resource allocated for the groupcast PSSCH, or ending at the end of the first transmit burst by the transmitting UE containing the groupcast PSSCH transmitted on the resource allocated for the groupcast PSSCH.

[0162] In one embodiment, the processor sets the contention window size of the priority class to the next highest allowed value or a calculated value min(CW × 2 + 1, CW) based on the number of NACKs received from multiple PSFCH opportunities corresponding to group cast PSFCHs that exceed a predefined value with respect to X% of PSFCH reception opportunities. max It is configured to be set to ), where CW is the contention window size.

[0163] In one embodiment, the processor, in response to detection that no PSFCH has been received for multiple PSFCH reception opportunities related to PSSCH transmission within a reference duration, sets the contention window size to CW min,p It is configured to be set to [this value].

[0164] In one embodiment, the reference duration corresponds to the duration of channel occupation initiated by the transmitting UE, starting from the start of channel occupation and continuing until at least one PSFCH receive opportunity is expected from at least one of several PSFCH receive opportunities in a PSFCH resource from a UE belonging to one or more groups of members of the same L2 destination ID.

[0165] In one embodiment, the processor is configured to maintain a constant contention window size adjustment in response to transmissions of transport blocks by a transmitting UE using blind retransmissions, broadcasts, HARQ-disabled transmissions, or any combination thereof within an occupied channel.

[0166] In one embodiment, the processor is configured to set the reference duration according to the first HARQ feedback-enabled PSSCH transmit within the reference duration, in response to a transmit UE transmitting a transport block using a mixture of blind retransmission and HARQ feedback-enabled transmit.

[0167] A first method for adjusting the contention window size for sidelink group casting is disclosed. The first method may be performed by a UE as described herein, for example, a remote unit 105 and / or a user equipment device 500. In some embodiments, the first method may be performed by a processor that executes program code, for example, a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0168] In one embodiment, the first method transmits PSCCH and PSSCH corresponding to group cast data transmission. In one embodiment, the first method receives a PSFCH including HARQ feedback after a predetermined number of slots of the corresponding group cast transmission. In one embodiment, the first method determines contention window size adjustment for group cast PSSCH based on transmitted group cast HARQ feedback related to PSSCH within a reference duration.

[0169] In one embodiment, the first method determines the contention window size adjustment for a device transmitting a groupcast PSSCH using HARQ feedback option 2, based on the percentage of ACK / NACK HARQ feedback received from UEs of one or more group members belonging to the same L2 destination ID.

[0170] In one embodiment, the first method determines the contention window size of the priority class based on at least Z=X% of HARQ-ACK values ​​determined to be "NACK" from UEs of one or more groups belonging to the same destination ID within the reference duration, by the next highest allowed value or a calculated value min(CW×2 + 1, CW max Set it to ), where CW is the contention window size.

[0171] In one embodiment, the first method sets the contention window size of the priority class to a minimum depending on at least Z=Y% of the HARQ-ACK values ​​that have been determined to be "ACKs" from UEs of one or more groups belonging to the same destination ID within the reference duration.

[0172] In one embodiment, failing to detect a PSFCH reception opportunity related to a PSSCH transmission within the reference duration indicates a "NACK" response.

[0173] In one embodiment, the first method detects that there is no PSFCH reception opportunity for a PSSCH transmission within the reference duration, and sets the contention window size to CW min,p Set to this.

[0174] In one embodiment, the Z=X% and / or Z=Y% values ​​for NACK and / or ACK, respectively, can be configured per resource pool, per UE, per destination group or carrier, or in any combination thereof, or they are fixed values.

[0175] In one embodiment, the first method determines the contention window size adjustment for a transmitting UE that sends a groupcast PSSCH using HARQ feedback option 1, based on a count of the number of NACKs received, or based on the absence of PSFCH feedback from multiple PSFCH opportunities corresponding to a groupcast PSSCH.

[0176] In one embodiment, the reference duration corresponds to the duration of channel occupation initiated by the transmitting UE, starting from the start of channel occupation and ending at the end of the first slot in which at least one groupcast PSSCH is transmitted on the resource allocated for the groupcast PSSCH, or ending at the end of the first transmit burst by the transmitting UE containing the groupcast PSSCH transmitted on the resource allocated for the groupcast PSSCH.

[0177] In one embodiment, the first method determines the contention window size of the priority class based on the number of NACKs received from multiple PSFCH opportunities corresponding to groupcast PSFCHs that exceed a predetermined value with respect to X% of PSFCH reception opportunities, by the next highest allowed value or a calculated value min(CW × 2 + 1, CW max Set it to ), where CW is the contention window size.

[0178] In one embodiment, the first method detects that there is no PSFCH reception for multiple PSFCH reception opportunities related to PSSCH transmission within a reference duration, and sets the contention window size CW min,p Set to this.

[0179] In one embodiment, the reference duration corresponds to the duration of channel occupation initiated by the transmitting UE, starting from the start of channel occupation and continuing until at least one PSFCH receive opportunity is expected from at least one of several PSFCH receive opportunities in a PSFCH resource from a UE belonging to one or more groups of members of the same L2 destination ID.

[0180] In one embodiment, the first method maintains a constant contention window size adjustment in response to a transport block transmission by a transmitting UE using blind retransmission, broadcast, HARQ-disabled transmission, or any combination thereof within an occupied channel.

[0181] In one embodiment, the first method sets the reference duration according to the first HARQ feedback-enabled PSSCH transmission within the reference duration, in response to a transport block transmission by a transmitting UE using a mixture of blind retransmission and HARQ feedback-enabled transmission.

[0182] A second apparatus for a contention window resizing procedure for sidelink groupcasting is disclosed. The second apparatus may include network devices described herein, for example, base unit 121, gNB, and / or network equipment apparatus 600. In some embodiments, the second apparatus may include a processor that executes program code, for example, a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0183] In one embodiment, the second device includes a processor and memory coupled to the processor. In one embodiment, the processor is configured to cause the device to receive PSCCH and PSSCH corresponding to group cast data transmissions. In one embodiment, the processor is configured to cause the device to transmit a PSFCH including HARQ feedback after a predetermined number of slots of the corresponding group cast transmission in order to determine contention window size adjustment for the group cast PSSCH based on transmitted group cast HARQ feedback related to the PSSCH within a reference duration.

[0184] A second method for adjusting the contention window size for sidelink groupcasts is disclosed. The second method may be performed by network devices described herein, for example, base unit 121, gNB, and / or network equipment device 600. In some embodiments, the second method may be performed by a processor executing program code, for example, a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0185] In one embodiment, the second method receives PSCCH and PSSCH corresponding to group cast data transmissions. In one embodiment, the second method transmits a PSFCH containing HARQ feedback after a predetermined number of slots of the corresponding group cast transmission to determine contention window size adjustment for the group cast PSSCH based on transmitted group cast HARQ feedback related to the PSSCH within a reference duration.

[0186] The embodiments described may be carried out in other specific forms. The embodiments described should be considered illustrative in all respects only and not restrictive. Accordingly, the scope of the invention is indicated not by the above description but by the appended claims. All modifications that fall within the meaning and scope equivalent to the claims should be incorporated within the scope of the claims. [Explanation of symbols]

[0187] 100 Wireless Communication Systems 105 Remote Unit 107 applications 115 Wireless communication link 120 RAN 121 Base Unit 123 Wireless communication link 125 Side Link 130 Mobile Core Network 131 UPF 133 AMF 135 SMF 137 PCF 139 UDM / UDR 150 packet data network 151 Content Server 205 UE 302 Tx Remote UE (UE1) 304 Repeater (UE2) 306 Rx Remote UE (UE3) 400 NR protocol stack 405 User Plane Protocol Stack 410 Control Plane Protocol Stack 415 Physical Layer 420 MAC sublayer 425 RLC sublayer 430 PDCP sublayer 435 SDAP Layer 440 RRC sublayer 445 NAS Layers 500 User Equipment 505 Processor 510 memory 515 Input Devices 520 Output Devices 525 Transceiver 530 Transmitter 535 Receiver 540 Network Interfaces 545 Application Interfaces 600 Network Devices 605 Processor 610 memory 615 Input Devices 620 Output Devices 625 Transceiver 630 Transmitter 635 Receiver 640 network interfaces 645 Application Interfaces 700 methods 800 ways

Claims

1. User equipment ("UE") Processor and The memory coupled to the aforementioned processor and The processor includes, and the UE, Send a physical shared sidelink channel ("PSSCH") for transmitting groupcast data. After several slots of groupcast data transmission, a physical shared feedback channel ("PSFCH") is received, including groupcast hybrid auto retransmission request ("HARQ") feedback. Based on the groupcast HARQ feedback related to the PSSCH within the reference duration, the contention window size adjustment for groupcast data transmission is determined. It is configured in such a way, The processor is further configured to cause the UE to determine the contention window size adjustment based on the proportion of HARQ feedback, including ACKs or NACKs, received for the PSSCH within the reference duration from one or more UEs belonging to the same Layer 2 (L2) destination identifier (ID). The aforementioned reference duration corresponds to the channel occupation starting from the start of channel occupation and ending at the end of the first slot allocated for at least one groupcast PSSCH transmission, or ending at the end of the first transmission burst containing a groupcast PSSCH.

2. The processor provides the UE with a priority class value based on the proportion of NACKs in the HARQ feedback, which includes the ACK or NACK received from one or more UEs belonging to the same L2 destination ID for the PSSCH within the reference duration, or min(CW × 2 + 1, CW max The UE according to claim 1, configured to set the contention window size based on CW, where CW is the contention window size.

3. The UE according to claim 2, wherein the processor is configured to cause the UE to set the contention window size of the priority class to a minimum in proportion to the percentage of HARQ feedback, including the ACK or NACK, received for the PSSCH within the reference duration from one or more UEs belonging to the same L2 destination ID.

4. The UE according to claim 3, wherein the absence of a PSFCH during a PSFCH opportunity within the aforementioned reference duration indicates a NACK response.

5. The UE according to claim 3, wherein the percentage value of the HARQ feedback is comprised of a resource pool, a UE, a destination group or carrier, or a combination thereof.

6. The UE according to claim 2, wherein the processor is configured to cause the UE to determine contention window resizing for a groupcast PSSCH transmitting UE based on counting several received NACKs or based on the absence of PSFCH feedback in multiple PSFCH opportunities.

7. The processor provides the UE with respect to multiple PSFCH opportunities that are NACKs and exceed a predefined value with respect to the proportion of PSFCH opportunities, based on the priority class value or calculated value min(CW × 2 + 1, CW) for the proportion of HARQ feedback to the PSFCH within the reference duration, which includes the ACK or NACK received from one or more UEs belonging to the same L2 destination ID, according to the proportion of HARQ feedback to the PSFCH within the reference duration that is NACK with respect to multiple PSFCH opportunities and exceeds a predefined value with respect to the proportion of PSFCH opportunities, min(CW × 2 + 1, CW) max The UE according to claim 1, configured to set the contention window size based on CW, where CW is the contention window size.

8. The processor, in response to the detection by the UE that there is no PSFCH in multiple PSFCH opportunities within the reference duration, sets the contention window size to CW min,p The UE according to claim 1, configured to set CW min,p to the minimum contention window size for any priority class.

9. The UE according to claim 1, wherein the processor is configured to cause the UE to maintain a constant contention window size adjustment in response to a transmission of a transport block by a transmitting UE using blind retransmission, broadcast, HARQ-disabled transmission, or any combination thereof within an occupied channel.

10. The UE according to claim 1, wherein the processor is configured to cause the UE to set the reference duration in accordance with the first HARQ feedback-enabled PSSCH transmission within the reference duration.

11. A method performed by a user device ("UE"), The steps include sending a physical shared sidelink channel ("PSSCH") for transmitting groupcast data, The steps include receiving a Physical Shared Feedback Channel (PSFCH) containing Groupcast Hybrid Auto-Retransmission Request ("HARQ") feedback after several slots of Groupcast data transmission, A step of determining the contention window size adjustment for group cast data transmission based on the group cast HARQ feedback related to the PSSCH within the reference duration. Includes, The step further includes determining the contention window size adjustment based on the proportion of HARQ feedback, including ACKs or NACKs, received for the PSSCH within the reference duration from one or more UEs belonging to the same Layer 2 (L2) destination identifier (ID), A method in which the reference duration corresponds to the channel occupation starting from the start of channel occupation and ending with the end of the first slot allocated for at least one groupcast PSSCH transmission, or ending with the end of the first transmission burst containing a groupcast PSSCH.

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