Channel access priority class selection for sidelink operation with shared spectrum channel access

Abstract

Aspects of the present disclosure relate to sidelink (SL) operation in a cell with shared spectrum channel access. A UE (600) may be configured to generate (902) an SL transport block to be transmitted to a set of Rx UEs, the TB including data units from a plurality of SL LCHs, each SL LCH associated with a respective CAPC. The UE (600) may be configured to determine (904) a highest priority CAPC associated with the SL TB, and select (906) a CAPC value for the SL TB based at least in part on the highest priority CAPC satisfying a threshold. The UE (600) may be configured to perform (908) an LBT procedure using a parameter corresponding to the selected CAPC value, and transmit (910) the SL TB based at least in part on a success of the LBT procedure.

Description

Technical Field

[0001] The present disclosure relates to wireless communications, and more particularly, to channel access priority class (CAPC) selection for sidelink (SL) operation in a cell with shared spectrum channel access considering packet delay budget (PDB) requirements. Background Art

[0002] A wireless communication system may include one or more network communication devices, such as a base station, which may be referred to as an evolved Node B (eNB), a next generation Node B (gNB), or other suitable terms. Each network communication device (such as a base station) may support wireless communication of one or more user communication devices, which may be referred to as user equipment (UE) or other suitable terms. A wireless communication system may support wireless communication with one or more user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, time slots, subframes, frames, etc.) or frequency resources (e.g., subcarriers, carriers)). In addition, a wireless communication system may support wireless communication across various radio access technologies, including third generation (3G) radio access technology (RAT), fourth generation (4G) RAT, fifth generation (5G) RAT, and other suitable RATs other than 5G (e.g., sixth generation (6G)).

[0003] Sidelink communication refers to peer-to-peer communication directly between UEs. Thus, the UEs communicate with each other without relaying the communication via a mobile network (ie, no base station is required). Summary of the invention

[0004] The article "one" before an element is not limited and should be understood to mean "at least one" of those elements or "one or more" of those elements. The terms "one", "at least one", "one or more" and "at least one of one or more" may be interchangeable. As used herein, included in the claims, "or" (e.g., a list of items beginning with phrases such as "at least one" or "one or more" or "one or both") used in a list of items indicates an inclusive list, so that, for example, a list of at least one of A, B or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). In addition, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, without departing from the scope of the present disclosure, the example steps described as "based on condition A" may be based on both condition A and condition B. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part". In addition, as used herein, included in the claims, a "group" may include one or more elements.

[0005] Some implementations of the methods and apparatus described herein may include a UE comprising means for generating a SL transport block to be transmitted on a sidelink channel to a group of receiving UEs (Rx UEs), wherein the transport block (TB) comprises data units associated with a plurality of SL logical channels (LCHs), each LCH being associated with a respective channel access priority class (CAPC). The UE described herein may further include means for determining a highest priority CAPC associated with the SL TB, and means for selecting a CAPC value for the SL TB based at least in part on the highest priority CAPC satisfying a threshold. The UE described herein may further include means for performing a listen-before-talk (LBT) procedure using a set of LBT parameters corresponding to the selected CAPC value, and means for transmitting the SL TB based at least in part on the success of the LBT procedure. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 An example of a wireless communication system according to aspects of the present disclosure is described.

[0007] Figure 2 An example of a 3rd Generation Partnership Project (3GPP) New Radio (NR) protocol stack showing different protocol layers in a UE and a network is described according to aspects of the present disclosure.

[0008] Figure 3 An example of a radio frame during which an LBT process is performed according to aspects of the present disclosure is illustrated.

[0009] Figure 4 An example of a SL protocol stack showing different protocol layers in a pair of UEs is illustrated according to aspects of the present disclosure.

[0010] Figure 5 An example of a medium access control (MAC) protocol data unit (PDU) for SL operation in a cell with shared spectrum channel access according to aspects of the present disclosure is illustrated.

[0011] Figure 6 An example of a user equipment (UE) 600 is illustrated in accordance with aspects of the present disclosure.

[0012] Figure 7 An example of a processor 700 according to aspects of the present disclosure is illustrated.

[0013] Figure 8 An example of a network equipment (NE) 800 according to aspects of the present disclosure is illustrated.

[0014] Fig. 9A flow chart illustrating a first method of performing CAPC selection for SL operation by a UE in a cell with shared spectrum channel access according to aspects of the present disclosure.

[0015] Fig.10 A flow chart illustrating a second method of performing CAPC selection for SL operation by a UE in a cell with shared spectrum channel access according to aspects of the present disclosure.

[0016] Fig.11 A flow chart illustrating a third method of performing CAPC selection by a UE for SL operation in a cell with shared spectrum channel access according to aspects of the present disclosure.

[0017] Fig.12 A flow chart illustrating a fourth method of performing CAPC selection for SL operation by a UE in a cell with shared spectrum channel access according to aspects of the present disclosure.

[0018] Fig.13 A flow chart illustrating a fifth method of performing CAPC selection for SL operation by a UE in a cell with shared spectrum channel access according to aspects of the present disclosure. DETAILED DESCRIPTION

[0019] In general, the present disclosure describes systems, methods, and devices for CAPC selection for SL operation in a cell with shared spectrum channel access. In some embodiments, the method may be performed using a computer executable code embedded on a computer readable medium. In some embodiments, a device or system may include a computer readable medium containing computer readable code, which, when executed by a processor, causes the device or system to perform at least a portion of the solution described below.

[0020] In certain wireless communication networks, such as in NR unlicensed (NR-U) operation, channel access in both downlink (DL) and uplink (UL) relies on the LBT process to determine channel availability. In such embodiments, the radio node (e.g., base station unit (e.g., gNB) and / or UE) must first sense the channel to find that there is no ongoing communication before any transmission. When the communication channel is a wide bandwidth unlicensed carrier, the clear channel assessment (CCA) process relies on detecting energy levels on multiple subbands of the communication channel. In some embodiments, LBT in NR-U does not take beamforming into account and only omni-directional LBT is used.

[0021] In various embodiments, for example, for NR-U, LBT failure handling includes: 1) the MAC entity relies on receiving notification of UL LBT failure from the physical (PHY) layer to detect consecutive UL LBT failures; 2) if there is another BWP with configured RACH resources, the UE switches to another bandwidth part (BWP) and initiates a random access channel (RACH) when consecutive LBT failures are declared on the primary cell (PCell) or primary serving cell (PSCell); 3) if consecutive UL LBT failures are detected on the PCell and UL LBT failures are detected on "N" possible BWPs, the UE should perform radio link failure (RLF) recovery; 4) if consecutive UL LBT failures are detected on the PSCell, the UE detects consecutive UL LBT failures on "N" BWPs. After LBT failure, the mobile network (MN) is notified via the secondary cell group (SCG) failure information process; 5) "N" is the number of configured BWPs with configured physical random access channel (PRACH) resources - if N is greater than 1, then the UE implementation determines which BWP the UE selects; and / or 6) If consecutive UL LBT failures are detected on the secondary cell (SCell), a new MAC control element (CE) is used to report this to the node to which the SCell belongs.

[0022] In some embodiments, UEs with consecutive LBT failures are allowed to autonomously switch UL BWPs. Other UL BWPs of the NR-U cell may not experience a large number of LBT failures (e.g., different LBT subbands are used for different UL BWPs).

[0023] In some embodiments, such as for Long Term Evolution (LTE) enhanced License Assisted Access (eLAA), autonomous uplink (AUL) transmissions are enabled by a combination of radio resource control (RRC) signaling and an activation message conveyed by downlink control information (DCI) in a physical control channel. The RRC configuration includes the subframes in which the UE is allowed to transmit autonomously, and a hybrid automatic repeat request (HARQ) process identifier (ID) that is eligible. The activation message includes a resource block assignment (RBA) and a modulation and coding scheme (MCS), from which the UE can determine the transport block size for any AUL transmission.

[0024] In various embodiments, it is possible to autonomously retransmit data related to a transport block (TB) that has not been correctly received by the eNB. For this purpose, the UE monitors downlink feedback information (DFI) (e.g., AUL-DFI), which may be transmitted by the eNB and includes HARQ acknowledgement (HARQ-ACK) information for the AUL enabled HARQ process ID. As used herein, HARQ-ACK may collectively represent positive acknowledgement (ACK) and negative acknowledgement (NACK). In certain embodiments, HARG-ACK also represents discontinuous transmission (DTX). ACK means that the TB is received correctly, while NACK means that the TB is received in error. DTX indicates that no transmission was detected by the receiving device.

[0025] If the UE detects a NACK message, it may attempt to autonomously access the channel to retransmit the same transport block in the corresponding HARQ process. As a safety measure to prevent errors, the AUL transmission includes at least the HARQ process ID and a new data indicator (NDI) accompanying the physical uplink shared channel (PUSCH) (e.g., AUL uplink control information (AUL-UCI)).

[0026] In certain embodiments, it is possible for the eNB to transmit an UL grant via a DCI that assigns UL resources for retransmission of the same transport block using the indicated HARQ process. It is further possible for the eNB to transmit an UL grant via a DCI that assigns UL resources for transmission of a new transport block using the indicated HARQ process. In other words, even if the HARQ process ID may be eligible for AUL transmission, the eNB still has access to this process at any time via a scheduling grant (e.g., DCI). In general, if a UE detects a grant for UL transmission for a subframe that is eligible for AUL (e.g., according to the RRC configuration), it will follow the received grant and will not perform AUL transmission in that subframe. Table 1 illustrates one embodiment of the fields of the AUL-UCI.

[0027] Table 1: Fields of AUL-UCI

[0028]

[0029] In some embodiments, COT sharing is demonstrated by: 1) sharing UE-initiated channel occupancy (e.g., configured grant (CG) PUSCH (i.e., "CG-PUSCH") or scheduled UL) with supported gNBs such that the gNB is allowed to transmit control signals, broadcast signals, control channels, and / or broadcast channels for any UE as long as the transmission contains transmissions for the UE that initiated channel occupancy (CO) and / or DL ​​signals and / or channels (e.g., physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), reference signals) for the UE that initiated channel occupancy; 2) if configured by the gNB (e.g., RRC signaling), the threshold (e.g., energy detection (ED) threshold) that the UE applies when initiating channel occupancy to be shared with the gNB, a) if not configured, the threshold that the UE applies when initiating channel occupancy to be shared with the gNB, Then the gNB's transmission in the UE-initiated COT may only include control and / or broadcast signals and / or channel transmissions of up to 2, 4 and / or 8 orthogonal frequency division multiplexing (OFDM) symbols with a duration of 15, 30 and / or 60 kHz subcarrier spacing (SCS), and b) if it cannot be assumed based on regulations that a wireless local area network (WLAN) (e.g., Wireless Fidelity or "Wi-Fi") is not present, then the threshold that the gNB configures the UE to apply when starting channel occupancy is determined based on the maximum gNB transmit (TX) power; 3) Use Category 2 LBT (e.g., for gaps of 16us and 25us); 4) Use Category 1 LBT under the following conditions: a) gap duration <= 16us, b) if the gNB transmission contains only control and / or broadcast signals and / or channels, then the gNB's transmission is performed after the first handover between the UE and the gNB, and c) if the gNB transmission has a duration less than X ms (e.g., X>=0), then the gNB's transmission is performed after the first handover between the UE and the gNB.

[0030] In various embodiments, for a Class 2 LBT in a 16us gap, a total of at least 5us of energy measurements are made, with at least 4us of sensing falling within the 9us time slot immediately prior to the transmission. If the measured energy is below a threshold, the LBT is called successful.

[0031] In certain embodiments, the NR-U LBT process for channel access may be summarized as follows: 1) both gNB-initiated and UE-initiated COTs use Category 4 (Cat4) LBT, where the start of a new transmission burst always performs LBT with exponential backoff—except only when the duration of the demodulation reference signal (DRS) is at most 1 ms and is not multiplexed with the unicast PDSCH; and / or 2) UL transmissions within a gNB-initiated COT or subsequent DL transmissions within a UE- or gNB-initiated COT may be transmitted immediately without sensing only if the gap with the end of the previous transmission does not exceed 16 μs, otherwise Category 2 LBT must be used and the gap cannot exceed 25 μs.

[0032] In some embodiments, the UE and / or gNB in ​​the unlicensed carrier must perform LBT operation, and within Category 4 LBT, several CAPCs are defined to have differentiated channel access parameters, as shown in Table 2 (for DL ​​case) and Table 3 (for UL case).

[0033] Table 2: CAPC for DL

[0034]

[0035]

[0036] Table 3: CAPC for UL

[0037]

[0038] It should be noted that for Table 3, for p=3,4, if the higher layer parameter absenceOfAnyOtherTechnology-r14 or absenceOfAnyOtherTechnology-r16 is provided, then T ulm cot,p =10ms, otherwise T ulm cot,p =6ms. When T ulm cot,p = 6 ms, it may be increased to 8 ms by inserting one or more gaps. The minimum duration of a gap should be 100 μs. The maximum duration before the inclusion of any such gap should be 6 ms.

[0039] According to the current 3GPP specification, for the case when a TB does not contain a MAC CE or a signaling radio bearer (SRB), the UE selects the lowest priority CAPC of the LCH where the MAC service data unit (SDU) is multiplexed in the TB. For example, when the Tx UE selects a CAPC value, applying the same behavior to the sidelink transmission will potentially lead the UE to select a high CAPC index (e.g., because the TB contains lower priority data), even if the sidelink resources are selected according to the PDB of the TB determined based on the LCH with the most stringent PDB requirements. Therefore, there may be a mismatch between the CAPC value selected for the TB and the PDB of the TB.

[0040] In the prior art solution, the Tx UE will select the lowest priority CAPC value of the LCH where the MAC SDU is multiplexed in the TB. Therefore, there may be a mismatch between the CAPC value determined for the TB and the PDB of the TB. For example, the LBT process including the contention window determined according to the CAPC (e.g., as described in 3GPP Technical Specification (TS) 37.213 clauses 4.1.1, 4.1.2, 4.2.1.1, 4.2.2.2) may not meet the conditions that allow transmission before the PDB of the TB expires, for example, the required minimum total channel access sensing duration may be too large. Therefore, the prior art solution may result in the selection of incorrect channel access parameters for the SL TB.

[0041] In the first set of solutions, for the case when the highest priority CAPC of the SL LCH is higher than the preconfigured CAPC threshold, the UE selects the highest priority CAPC of the SL logical channel (e.g., Sidelink Traffic Channel (STCH)) in which the MAC SDU is multiplexed in the TB. Otherwise, that is, for the case where the highest priority CAPC value of the SL logical channel is lower than the preconfigured CAPC threshold, the UE selects the lowest priority CAPC of the SL logical channel in which the MAC SDU is multiplexed in the TB.

[0042] In another set of solutions, if there is data with the highest priority CAPC contained in the TB, that is, the highest priority CAPC=1, then the UE uses the highest priority CAPC for the SL TB. According to one implementation of the embodiment, such data may be: SL MAC CE, or Sidelink Control Channel (SCCH) MAC SDU, or Sidelink Broadcast Control Channel (SBCCH) MAC SDU, or STCH MAC SDU. According to this embodiment, it is ensured that for the case where the SL TB includes data with the highest priority CAPC, no matter what other data is multiplexed in the SL TB, the UE uses the highest priority CAPC for transmitting the SL TB.

[0043] Aspects of the disclosure are described in the context of a wireless communication system.

[0044] Figure 1 An example of a wireless communication system 100 according to aspects of the present disclosure is described. The wireless communication system 100 may include one or more NEs 102, one or more UEs 104, and a core network (CN) 106. The wireless communication system 100 may support various radio access technologies. In some implementations, the wireless communication system 100 may be a 4G network, such as an LTE network or an LTE Advanced (LTE-A) network. In some other implementations, the wireless communication system 100 may be an NR network, such as a 5G network, a 5G Advanced (5G-A) network, or a 5G Ultra Wideband (5G-UWB) network. In other implementations, the wireless communication system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technologies, including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20. The wireless communication system 100 may support radio access technologies other than 5G, such as 6G. Additionally, the wireless communication system 100 may support technologies such as time division multiple access (TDMA), frequency division multiple access (FDMA), or code division multiple access (CDMA).

[0045] One or more NEs 102 may be dispersed throughout a geographic area to form a wireless communication system 100. One or more of the NEs 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a network function, a network entity, a radio access network (RAN), a NodeB, an eNodeB (eNB), a next generation NodeB (gNB), or other suitable terms. The NE 102 and the UE 104 may communicate via a communication link, which may be a wireless or wired connection. For example, the NE 102 and the UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) via a Uu interface.

[0046] NE 102 may provide a geographic coverage area within which NE 102 may support services for one or more UE 104. For example, NE 102 and UE 104 may support wireless communications of signals associated with services (e.g., voice, video, packet data, messaging, broadcast, etc.) according to one or more radio access technologies. In some implementations, NE 102 may be mobile, such as a satellite associated with a non-terrestrial network (NTN). In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but different geographic coverage areas may be associated with different NE 102.

[0047] One or more UEs 104 may be dispersed throughout a geographic area of ​​the wireless communication system 100. UE 104 may include or may be referred to as a remote unit, a mobile device, a wireless device, a remote device, a subscriber device, a transmitter device, a receiver device, or some other suitable terminology. In some implementations, UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally or alternatively, UE 104 may be referred to as an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a Machine Type Communication (MTC) device, among other examples.

[0048] The UE 104 may be capable of supporting wireless communications directly with other UEs 104 via a communication link. For example, the UE 104 may support wireless communications directly with another UE 104 via a device-to-device (D2D) communication link. In some embodiments, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a side link. For example, the UE 104 may support wireless communications directly with another UE 104 via a PC5 interface.

[0049] NE 102 may support communication with CN 106 or with another NE 102 or both. For example, NE 102 may interface with other NE 102 or CN 106 via one or more backhaul links (e.g., S1, N2, N2 or network interface). In some embodiments, NE 102 may communicate directly with each other. In some other embodiments, NE 102 may communicate with each other or indirectly (e.g., via CN 106). In some embodiments, one or more NE 102 may include subcomponents, such as access network entities, which may be instances of access node controllers (ANCs). ANC may communicate with one or more UE 104 via one or more other access network transmission entities (which may be referred to as radio heads, smart radio heads, or transmit-receive points (TRPs)).

[0050] The CN 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The CN 106 may be an evolved packet core (EPC) or a 5G core (5GC), which may include control plane entities that manage access and mobility (e.g., mobility management entity (MME), access and mobility management function (AMF)) and user plane entities that route or interconnect packets to external networks (e.g., serving gateway (S-GW), packet data network (PDN) gateway (P-GW), or user plane function (UPF)). In some implementations, the control plane entities may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearer, signal bearer, etc.) of one or more UEs 104 served by one or more NEs 102 associated with the CN 106.

[0051] The CN 106 may communicate with a packet data network via one or more backhaul links (e.g., via S1, N2, N2 or another network interface). The packet data network may include an application server. In some implementations, one or more UEs 104 may communicate with the application server. The UE 104 may establish a session (e.g., a protocol data unit (PDU) session, etc.) with the CN 106 via the NE 102. The CN 106 may use the established session (e.g., an established PDU session) to route traffic (e.g., control information, data, etc.) between the UE 104 and the application server. A PDU session may be an example of a logical connection between the UE 104 and the CN 106 (e.g., one or more network functions of the CN 106).

[0052] In the wireless communication system 100, the NE 102 and the UE 104 may use the resources of the wireless communication system 100 (e.g., time resources (e.g., symbols, time slots, subframes, frames, etc.) or frequency resources (e.g., subcarriers, carriers)) to perform various operations (e.g., wireless communication). In some implementations, the NE 102 and the UE 104 may support different resource structures. For example, the NE 102 and the UE 104 may support different frame structures. In some implementations, such as in 4G, the NE 102 and the UE 104 may support a single frame structure. In some other implementations, such as in 5G and other suitable radio access technologies, the NE 102 and the UE 104 may support various frame structures (i.e., multiple frame structures). The NE 102 and the UE 104 may support various frame structures based on one or more parameter sets.

[0053] One or more parameter sets may be supported in the wireless communication system 100, and the parameter sets may include subcarrier spacing and cyclic prefixes. A first parameter set (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, a first parameter set (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second parameter set (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third parameter set (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth parameter set (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth parameter set (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

[0054] The time intervals of resources (e.g., communication resources) may be organized according to frames (also referred to as radio frames). Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some embodiments, each frame may include a plurality of subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some embodiments, each frame may have the same duration. In some embodiments, each subframe of a frame may have the same duration.

[0055] In addition or alternatively, the time intervals of resources (e.g., communication resources) may be organized according to time slots. For example, a subframe may include a number of time slots (e.g., quantity). The number of time slots in each subframe may also depend on one or more parameter sets supported in the wireless communication system 100. For example, the first, second, third, fourth, and fifth parameter sets (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings of 15kHz, 30kHz, 60kHz, 120kHz, and 240kHz may utilize a single time slot per subframe, two time slots per subframe, four time slots per subframe, eight time slots per subframe, and 16 time slots per subframe, respectively. Each time slot may include a number of symbols (e.g., OFDM symbols) (e.g., quantity). In some implementations, the number of time slots of a subframe (e.g., quantity) may depend on the parameter set. For a conventional cyclic prefix, a time slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable to a 60kHz subcarrier spacing), a time slot may include 12 symbols. The relationship between the number of symbols per time slot, the number of time slots per subframe, and the number of time slots per frame for normal cyclic prefix and extended cyclic prefix may depend on the parameter set. It should be understood that references to a first parameter set (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15kHz) may be used interchangeably between subframes and time slots.

[0056] In the wireless communication system 100, the electromagnetic (EM) spectrum may be divided into various categories, frequency bands, channels, etc. based on frequency or wavelength. By way of example, the wireless communication system 100 may support one or more operating frequency bands, such as the frequency range designations FR1 (410 MHz to 7.125 GHz), FR2 (24.25 GHz to 52.6 GHz), FR3 (7.125 GHz to 24.25 GHz), FR4 (52.6 GHz to 114.25 GHz), FR4a or FR4-1 (52.6 GHz to 71 GHz), and FR5 (114.25 GHz to 300 GHz). In some implementations, the NE 102 and the UE 104 may perform wireless communications on one or more of the operating frequency bands. In some implementations, FR1 may be used by the NE 102 and the UE 104 as well as other equipment or devices for cellular communication traffic (e.g., control information, data). In some implementations, FR2 may be used by the NE 102 and UE 104 and other equipment or devices for short range, high data rate capabilities.

[0057] FR1 may be associated with one or more parameter sets (e.g., at least three parameter sets). For example, FR1 may be associated with a first parameter set (e.g., μ=0) including a 15 kHz subcarrier spacing; a second parameter set (e.g., μ=1) including a 30 kHz subcarrier spacing; and a third parameter set (e.g., μ=2) including a 60 kHz subcarrier spacing. FR2 may be associated with one or more parameter sets (e.g., at least 2 parameter sets). For example, FR2 may be associated with a third parameter set (e.g., μ=2) including a 60 kHz subcarrier spacing; and a fourth parameter set system (e.g., μ=3) including a 120 kHz subcarrier spacing.

[0058] Wireless communications in unlicensed spectrum (also known as "shared spectrum") offer some significant cost advantages over licensed spectrum, allowing communications to avoid overlapping an operator's licensed spectrum and instead use unlicensed spectrum in accordance with local regulations in a particular geographic area. From a 3rd Generation Partnership Project (3GPP) technology perspective, unlicensed operations can be performed over the Uu interface (referred to as NR-U) or can also be performed over a sidelink interface (e.g., SL-U).

[0059] For initial access, the UE 104 detects candidate cells and performs DL synchronization. For example, a gNB (e.g., an embodiment of the NE 102) may transmit a synchronization signal and a broadcast channel (SS / PBCH) transmission (referred to as a synchronization signal block (SSB)). The synchronization signal is a predefined data sequence known to the UE 104 (or may be derived using information already stored at the UE 104) and is located at a predefined time position relative to a frame / subframe boundary, etc. The UE 104 searches for the SSB and uses the SSB to obtain DL timing information (e.g., symbol timing) for DL ​​synchronization. The UE 104 may also decode system information (SI) based on the SSB. It should be noted that with beam-based communication, each DL beam may be associated with a corresponding SSB.

[0060] After performing DL synchronization and acquiring basic system information (e.g., Master Information Block (MIB) and System Information Block Type 1 (SIB1)), the UE 104 performs uplink (UL) synchronization and resource request by performing a random access procedure (referred to as a "RACH procedure") by selecting a preamble and transmitting the preamble on a physical random access channel (PRACH). The PRACH preamble is transmitted during a RACH opportunity (i.e., a set of predetermined time-frequency resources that can be used to receive the PRACH preamble). It should be noted that with beam-based communication, the UE 104 can select a certain DL beam and transmit the PRACH preamble on the corresponding UL beam. In such embodiments, there may be a mapping between SSBs and RACH opportunities, allowing the network to determine which beam the UE 104 has selected.

[0061] To complete the RACH process, after transmitting the PRACH preamble (also referred to as "Msg1"), the UE 104 monitors for a random access response (RAR) message (also referred to as "Msg2"). The gNB transmits UL timing adjustment information in the RAR and may also schedule UL resources (referred to as an initial uplink grant).

[0062] Figure 2 An example of an NR protocol stack 200 according to aspects of the present disclosure is illustrated. Figure 2UE 206, RAN node 208, and 5G core network (5GC) 210 (e.g., including at least one AMF) are shown, but these represent a set of UEs 104 interacting with NE 102 (e.g., base station) and CN 106. As depicted, NR protocol stack 200 includes user plane protocol stack 202 and control plane protocol stack 204. User plane protocol stack 202 includes PHY layer 212, MAC sublayer 214, radio link control (RLC) sublayer 216, packet data convergence protocol (PDCP) sublayer 218, and service data adaptation protocol (SDAP) layer 220. Control plane protocol stack 204 includes PHY layer 212, MAC sublayer 214, RLC sublayer 216, and PDCP sublayer 218. Control plane protocol stack 204 also includes radio resource control (RRC) layer 222 and non-access stratum (NAS) layer 224.

[0063] The AS layer 226 (also referred to as the "AS protocol stack") of the user plane protocol stack 202 is composed of at least SDAP, PDCP, RLC and MAC sublayers and a physical layer. The AS layer 228 of the control plane protocol stack 204 is composed of at least RRC, PDCP, RLC and MAC sublayers and a physical layer. Layer 1 (L1) includes the PHY layer 212. Layer 2 (L2) is divided into the SDAP sublayer 220, the PDCP sublayer 218, the RLC sublayer 216 and the MAC sublayer 214. Layer 3 (L3) includes the RRC layer 222 and the NAS layer 224 of the control plane, and includes, for example, an Internet Protocol (IP) layer and / or a PDU layer (not depicted) of the user plane. L1 and L2 are referred to as "lower layers", while L3 and above (e.g., transport layer, application layer) are referred to as "higher layers" or "upper layers".

[0064] The PHY layer 212 provides a transport channel to the MAC sublayer 214. The PHY layer 212 may perform a beam failure detection process using an energy detection threshold, as described herein. In certain embodiments, the PHY layer 212 may send an indication of a beam failure to a MAC entity at the MAC sublayer 214. The MAC sublayer 214 provides a logical channel to the RLC sublayer 216. The RLC sublayer 216 provides an RLC channel to the PDCP sublayer 218. The PDCP sublayer 218 provides a radio bearer to the SDAP sublayer 220 and / or the RRC layer 222. The SDAP sublayer 220 provides QoS flows to the core network (e.g., 5GC). The RRC layer 222 provides carrier aggregation and / or dual connectivity addition, modification, and release. The RRC layer 222 also manages the establishment, configuration, maintenance, and release of SRBs and data radio bearers (DRBs).

[0065] The NAS layer 224 is located between the UE 206 and the AMF in the 5GC 210. NAS messages are passed transparently through the RAN. The NAS layer 224 is used to manage the establishment of communication sessions and to maintain continuous communication with the UE 206 when the UE 206 moves between different cells of the RAN. In contrast, the AS layers 226 and 228 are located between the UE 206 and the RAN (i.e., the RAN node 208) and carry information through the wireless part of the network. Although Figure 2 Not depicted in FIG, but an IP layer exists above the NAS layer 224, a transport layer exists above the IP layer, and an application layer exists above the transport layer.

[0066] The MAC sublayer 214 is the lowest sublayer in the L2 architecture of the NR protocol stack. Its connection to the PHY layer 212 below is through transport channels, and its connection to the RLC sublayer 216 above is through logical channels. Therefore, the MAC sublayer 214 performs multiplexing and demultiplexing between logical channels and transport channels: the MAC sublayer 214 in the transmitting side constructs a MAC PDU (also called a transport block (TB)) from a MAC service data unit (SDU) received through a logical channel, and the MAC sublayer 214 in the receiving side recovers a MAC SDU from a MAC PDU received through a transport channel.

[0067] The MAC sublayer 214 provides data transfer services to the RLC sublayer 216 through a logical channel, which is a control logical channel carrying control data (e.g., RRC signaling) or a service logical channel carrying user plane data. On the other hand, data from the MAC sublayer 214 is exchanged with the PHY layer 212 through a transport channel, which is classified as UL or DL. Data is multiplexed into a transport channel depending on how it is transmitted over the air.

[0068] The PHY layer 212 is responsible for actually transmitting data and control information over the air interface, i.e., the PHY layer 212 carries all information from the MAC transport channel over the air interface on the transmit side. Some of the important functions performed by the PHY layer 212 include coding and modulation, link adaptation (e.g., adaptive modulation and coding (AMC)), power control, cell search and random access (for initial synchronization and handover purposes), and other measurements of the RRC layer 222 (within a 3GPP system (i.e., NR and / or LTE system) and between systems). The PHY layer 212 performs transmission based on transmission parameters (e.g., modulation scheme, coding rate (i.e., modulation and coding scheme (MCS)), number of physical resource blocks (PRBs), etc.).

[0069] It should be noted that the LTE protocol stack includes a similar structure to the NR protocol stack 200, except that the LTE protocol stack lacks the SDAP sublayer 220 in the AS layer 226, the EPC replaces the 5GC 510, and the NAS layer 224 is located between the UE 206 and the MME in the EPC. It should also be noted that the present disclosure distinguishes between protocol layers (e.g., the aforementioned PHY layer 212, MAC sublayer 214, RLC sublayer 216, PDCP sublayer 218, SDAP sublayer 220, RRC layer 222, and NAS layer 224) and the transmission layer (also referred to as "MIMO layer" or "data stream") in multiple-input multiple-output (MIMO) communications.

[0070] Figure 3 Depicts an LBT process 300 for a radio frame 302 for communications on an unlicensed spectrum in accordance with an embodiment of the present disclosure. When the communication channel is a wide bandwidth unlicensed carrier 304 (e.g., several hundred MHz), the CCA / LBT process relies on detecting energy levels on multiple subbands 306 of the communication channel, such as Figure 3 . LBT parameters (e.g., type / duration, clear channel assessment parameters, etc.) may be configured in UE 206 by RAN node 208. In one embodiment, the LBT process is performed at PHY layer 212.

[0071] Figure 3 Also depicted is the frame structure of a radio frame 302 for communication between a UE 206 and a RAN node 208 on an unlicensed spectrum. The radio frame 302 may be divided into subframes (indicated by subframe boundaries 308) and may be further divided into slots (indicated by slot boundaries 310). The radio frame 302 uses a flexible arrangement where UL and DL operations are on the same frequency channel but separated in time. However, a subframe is not configured as a DL subframe or a UL subframe, and a specific subframe may be used by a UE 206 or a RAN node 208. As previously discussed, LBT is performed prior to transmission. In the event that LBT does not coincide with a slot boundary 310, a reservation signal 312 may be transmitted to reserve (i.e., occupy) the channel until a slot boundary is reached and data transmission begins.

[0072] Regarding LBT failure handling, the MAC sublayer 214 relies on receiving notification of LBT failure from the PHY layer 212 to detect / declare consecutive UL LBT failures. If there is another BWP with configured random access channel (RACH) resources, the UE 206 switches to the other BWP and initiates a random access procedure (i.e., RACH procedure) when consecutive UL LBT failures on the PCell or PSCell are declared.

[0073] If continuous UL LBT failure is detected on PCell and UL LBT failure is detected on 'N' possible BWPs, then UE 206 performs RLF recovery. When continuous UL LBT failure is detected on PSCell, UE 206 notifies RAN via SCG Failure Information procedure after detecting continuous UL LBT failure on 'N' BWPs, where 'N' is the number of configured BWPs with configured PRACH resources. If 'N' is greater than one, it is determined by UE implementation which BWP the UE selects.

[0074] When continuous UL LBT failure is detected on the SCell, the UE 206 transmits a new MAC CE to report the continuous UL LBT failure to the node to which the SCell belongs. In some embodiments, the MAC CE can be used to report the failure on the PCell.

[0075] In other words, in case of continuous LBT failures, the UE 206 is allowed to switch UL BWP autonomously. The motivation is that other UL BWPs of the NR-U cell may not suffer from a large number of LBT failures, i.e., different LBT subbands 306 are used for different UL BWPs.

[0076] Figure 4 400 according to aspects of the present disclosure. Figure 4 A transmitting SL UE (denoted as "TxUE") 402 and a receiving SL UE (denoted as "RxUE") 404 are shown, but these represent a group of UEs that communicate using SL through the PC5 interface; other embodiments may involve different SL UEs. In various embodiments, each of Tx UE 402 and Rx UE 404 may be an embodiment of UE 104 and / or UE 206.

[0077] As depicted, the SL protocol stack 400 (i.e., the PC5 protocol stack) includes a PHY layer 406, a MAC sublayer 408, an RLC sublayer 410, a PDCP sublayer 412, an SDAP sublayer (e.g., for a user plane), and an RRC sublayer (e.g., for a control plane). Figure 4 In FIG. 4 , the SDAP sublayer and the RRC sublayer are depicted as a combined entity “RRC / SDAP layer” 414. Above the RRC / SDAP layer 414, there may be additional layers, such as a proximity service (ProSe) and / or V2X application layer 416.

[0078] The AS layer (also referred to as the “AS protocol stack”) for the control plane in the PC5 interface is composed of at least the RRC sublayer, the PDCP sublayer 412, the RLC sublayer 410, the MAC sublayer 408, and the PHY layer 406. The AS layer (also referred to as the “AS protocol stack”) for the user plane in the PC5 interface is composed of at least the SDAP sublayer, the PDCP sublayer 412, the RLC sublayer 410, the MAC sublayer 408, and the PHY layer 406.

[0079] Similar to the NR protocol stack 200, L1 refers to the PHY layer 406. L2 is divided into an SDAP sublayer, a PDCP sublayer 412, an RLC sublayer 410, and a MAC sublayer 408. L3 includes an RRC sublayer for the control plane, and includes, for example, an IP layer or a PDU layer for the user plane (not depicted). L1 and L2 are generally referred to as "lower layers", while L3 and above (e.g., transport layer, V2X layer, application layer) are referred to as "higher layers" or "upper layers". The PHY layer 406, MAC sublayer 408, RLC sublayer 410, and PDCP sublayer 412 perform the same operations as described above with reference to Figure 2 The PHY layer 212, MAC sublayer 214, RLC sublayer 216, and PDCP sublayer 218 may function similarly.

[0080] In various embodiments, SL communication involves one or more services that require SL connectivity, such as V2X services and ProSe services. The Tx UE 402 may establish one or more SL connections with nearby Rx UEs 404. For example, a V2X application running on the Tx UE 402 may generate data related to the V2X service and transmit the V2X data to one or more nearby Rx UEs 404 using the SL connection.

[0081] In NR-U, channel access in both DL and UL relies on the LBT procedure. The gNB and / or UE must first sense the channel to ascertain that there is no ongoing communication before any transmission. When the communication channel is a wide bandwidth unlicensed carrier, the LBT / CCA procedure relies on detecting the energy levels on multiple subbands of the communication channel, such as Figure 3 It should be noted that in Rel-16, LBT in NR-U does not consider beamforming and only omnidirectional LBT is assumed.

[0082] In LBT, a transmitter is expected to "sense" the medium based on a clear channel assessment (CCA) protocol and detect transmissions from other nodes before transmitting. The simplest CCA method is energy detection, for example, to measure the received energy level of signals transmitted from other devices and determine whether the channel is idle or busy.

[0083] Regarding SL operation in unlicensed spectrum, in Rel-16, sidelink communications were developed in the RAN, primarily to support advanced V2X applications. In Release 17 (Rel-17), proximity-based services including public safety and commercial related services were standardized. As part of Rel-17, energy-saving solutions (e.g., partial sensing, discontinuous reception (DRX)) and inter-UE coordination were developed to improve power consumption of battery-constrained terminals and reliability of sidelink transmissions.

[0084] Although NR sidelink was initially developed for V2X applications, there is growing interest in extending the applicability of NR sidelink to commercial use cases. For commercial sidelink applications, two key requirements have been identified: 1) increased sidelink data rates, and 2) new carrier frequencies to support the sidelink.

[0085] The increased sidelink data rates are motivated by applications such as sharing of sensor information (video) between vehicles with a high degree of driving automation. Commercial use cases may require data rates beyond what is possible in Rel-17. With support for sidelink carrier aggregation and sidelinks on unlicensed spectrum, increased data rates can be achieved. In addition, by enhancing FR2 sidelink operation, increased data rates can be supported more efficiently on FR2. While support for new carrier frequencies and larger bandwidths will also allow improvements to data rates, the main benefit will come from making the sidelink more suitable for a wider range of applications. More specifically, with support for unlicensed spectrum and enhancements to FR2, the sidelink will be in a better position to be implemented in commercial devices because utilization of the ITS band is limited to ITS safety-related applications.

[0086] Various systems may support sidelink communications on unlicensed spectrum for both Mode 1 and Mode 2, where Uu operation for Mode 1 is limited to licensed spectrum. In some embodiments, the channel access mechanism from NR-U (see above) Figure 3 Discussion) can be reused for SL-U operation, and the existing NR sidelink and NR-U channel structure can also be reused as a baseline for SL-U operation. In other words, the SL device performs LBT / CCA before occupying a channel on the unlicensed spectrum.

[0087] In NR-U, when UE 206 detects consecutive UL LBT failures, it takes actions specified in 3GPP TS 38.321 and as described above. Detection is per bandwidth part (BWP) and based on all UL transmissions within this BWP. For the case when the sidelink operates on a configured cell, corresponding UE actions need to be defined when consecutive LBT failures of sidelink transmissions are detected on a resource block (RB) set and / or resource pool (RP).

[0088] For unlicensed SL, once consecutive LBT failures have been declared, it particularly leads to a situation in which the SL receiver device (i.e., Rx UE 404) may not be able to transmit HARQ feedback on successful or failed reception to the corresponding SL transmitter device (i.e., Tx UE 402). In the absence of multiple such HARQ feedbacks, i.e., when sl-MaxNumConsecutiveDTX is reached, Tx UE 402 may infer that the link between it and Rx UE 404 has satisfied the RLF for NR sidelink communication transmissions, and the corresponding PC5-RRC connection is released.

[0089] Figure 5 5 is a schematic block diagram illustrating one embodiment of a MAC protocol data unit (PDU) 500 according to aspects of the present disclosure. The MAC PDU 500 includes a first MAC SDU (denoted as "MAC SDU 1") 502, a second MAC SDU (denoted as "MAC SDU 2") 504, and a third MAC SDU (denoted as "MAC SDU 3") 506. Here, the first MAC SDU 502 is formed by data associated with a first logical channel (denoted as "LCH X") and a specific CAPC value (here "CAPC 2"), the second MAC SDU 504 is formed by data associated with a second logical channel (denoted as "LCH Y") and a specific CAPC value (here "CAPC 3"), and the third MAC SDU 506 is formed by data associated with a third logical channel (denoted as "LCH Z") and a specific CAPC value (here "CAPC 4"). In various embodiments, the MAC PDU 500 forms a TB to be transmitted via SL communication.

[0090] In various embodiments, for dynamically scheduled UL resources (e.g., UL DCI), the gNB indicates the CAPC to be used by the UE for the corresponding UL transmission. For UL configured grants, the network cannot signal the CAPC index for each opportunity, and therefore the UE itself must select which CAPC to use for each opportunity. In certain embodiments, for a data radio bearer (DRB), the UE selects the highest CAPC index / value (e.g., corresponding to the lowest priority level) of the logical channels (LCHs) multiplexed in the TB. According to this mode, in Figure 5 In the example, the UE will select CAPC4 (eg, lowest priority) from Table 2.

[0091] In some embodiments, a very small amount of data belongs to the highest CAPC index, but the UE still has to apply the highest CAPC index to the high priority data, which causes some delay in the transmission. Therefore, for the UL CG, if the SRB (e.g., downlink control channel (DCCH)) SDU is included in the MAC PDU, the UE selects the CAPC index of the SRB (e.g., DCCH). Otherwise, the UE selects the highest CAPC index (e.g., lowest priority) of the LCH multiplexed in the MAC PDU. As used herein, "configured grant" (i.e., CG) refers to a semi-static allocation of resources, i.e., a grant for semi-persistent scheduling. Therefore, the gNB can use the CG to schedule PUSCH resources without using DCI for each transmission.

[0092] In some embodiments, the CAPC for radio bearers and MAC CEs is fixed or configurable as: 1) fixed as lowest priority for filling buffer status report (BSR) and recommended bit rate MAC CE; 2) fixed as highest priority for SRB0, SRB1, SRB3 and other MAC CEs; and / or 3) configured by the gNB for SRB2 and DRB.

[0093] In various embodiments, if a CAPC for a DRB is chosen, the gNB considers the fifth generation (5G) quality of service (QoS) ID (5QI) of all QoS flows multiplexed in the DRB, while considering fairness between different service types and transmissions. Table 4 shows which CAPC should be used for which standardized 5QIs (e.g., which CAPC is to be used for a given QoS flow). It should be noted that QoS flows corresponding to non-standardized 5QIs (e.g., operator-specific 5QIs) should use the CAPC of the standardized 5QI that best matches the QoS characteristics of the non-standardized 5QI. In Table 4, it should be noted that lower CAPC values ​​may mean higher priority.

[0094] Table 4: Mapping between CAPC and 5QI

[0095] CAPC 5Q 1 1,3,5,65,66,67,69,70,79,80,82,83,84,85 2 2,7,71 3 4,6,8,9,72,73,74,76 4 -

[0096] In certain embodiments, if Cat4 LBT (e.g., Type 1 LBT) is performed for the transmission of a UL TB, and if CAPC is not indicated in the DCI, the UE selects a CAPC as follows: 1) if only MAC CEs are included in the TB, then the highest priority CAPC for those MACCEs is used; 2) if common control channel (CCCH) SDUs are included in the TB, then the highest priority CAPC for the DCCH is used; 3) if dedicated control channel (DCCH) SDUs are included in the TB, then the highest priority CAPC for the DCCH is used; and / or 4) otherwise, the lowest priority CAPC for the logical channel in which the MAC SDUs are multiplexed in the TB is used.

[0097] According to the NR-U specified behavior for UL transmissions where CAPC is not indicated in the DCI, e.g., CG PUSCH transmissions, the UE selects the lowest priority CAPC of the LCH where MAC SDUs are multiplexed in the TB for the case when the TB does not contain a MAC CE or SRB.

[0098] Applying the same behavior for sidelink transmissions on the shared spectrum, e.g. allowing the Tx UE to follow the existing rules (as above) to determine the CAPC value will potentially lead to some situations where the UE has to select a high CAPC index for transmission of a TB, i.e. because the TB contains low priority data, but e.g. for Mode 2 resource selection, the sidelink resources are selected based on the PDB of the TB determined based on the LCH with the most stringent PDB requirements (high priority data is also multiplexed in the TB). Therefore, there may be a mismatch between the CAPC value determined for the TB and the PDB of the TB. For example, the LBT process - including the contention window determined based on the CAPC - may not be able to achieve the conditions that allow transmission before the PDB of the TB expires, e.g. the required minimum total channel access sensing duration may be too large.

[0099] Described below is a solution that allows efficient CAPC handling of sidelink transmissions, taking into account the PDB requirements of LCHs multiplexed in a TB on a cell configured with shared spectrum and fairness to other users (e.g., Wi-Fi users). If the highest priority CAPC is above a preconfigured threshold, the UE selects the highest priority CAPC of the SL logical channel (e.g., STCH) in which the MAC SDU is multiplexed in the TB to ensure that the PDB of the TB can be met.

[0100] Although presented as different solutions, one or more of the solutions described herein may be combined with one another to implement efficient CAPC handling for sidelink transmissions.

[0101] According to an embodiment of the first solution, for the case when the highest priority CAPC of the SL LCH is higher than the preconfigured CAPC threshold, the UE selects the highest priority CAPC of the SL logical channel (e.g., STCH) in which the MAC SDU is multiplexed in the TB. It should be noted that a lower CAPC value corresponds to a higher CAPC priority, i.e., CAPC=1 corresponds to the highest CAPC priority.

[0102] According to one implementation of the first solution, for the case where the SL TB does not contain a SL MAC CE and / or SCCH SDU and / or SBCCH SDU, when the highest priority CAPC of the SL LCH is higher than the preconfigured CAPC threshold, the UE selects the highest priority CAPC of the SL logical channel (i.e., STCH) in which the MAC SDU is multiplexed in the TB. Otherwise, that is, for the case where the highest priority CAPC value of the SL logical channel is lower than the preconfigured CAPC threshold, the UE selects the lowest priority CAPC of the SL logical channel in which the MAC SDU is multiplexed in the TB.

[0103] According to one implementation of the first solution, for the case where the CAPC is not indicated in the control information (e.g., DCI or sidelink control information (SCI)) (e.g., for mode 2 resource allocation), when (or before) performing LBT for transmission of sidelink TBs, the UE selects the CAPC according to some predefined rules. Such rules may be, for example, one of the following or a combination thereof, where the combination may be a logical OR combination:

[0104] Use the highest priority SL CAPC: A) if only SL MAC CE is contained in the SL TB; B) if SCCH SDU is contained in the SL TB, then use the highest priority SL CAPC; or C) if SBCCH SDU is contained in the SL TB, then use the highest priority SL CAPC.

[0105] In this embodiment, for the case when the highest priority SL CAPC is above the predefined CAPC threshold, the highest priority SL CAPC of the SL logical channel (e.g., STCH) in which the MAC SDU is multiplexed in the SL TB is additionally used. For the case when the highest priority SL CAPC is equal to or lower than the predefined CAPC threshold, the lowest priority SL CAPC of the SL logical channel (e.g., STCH) in which the MAC SDU is multiplexed in the SLTB is additionally used.

[0106] According to another implementation of the first solution, for the case where the CAPC is not indicated in the control information (e.g., DCI or SCI), when (or before) performing LBT for transmission of the sidelink TB, the UE selects the CAPC according to some predefined rules. Such rules may be, for example, one of the following or a combination thereof, where the combination may be a logical OR combination:

[0107] Use the highest priority SL CAPC: A) if only SL MAC CE is contained in the SL TB; B) if SCCH SDU is contained in the SL TB, then use the highest priority SL CAPC; or C) if SBCCH SDU is contained in the SL TB, then use the highest priority SL CAPC.

[0108] In this embodiment, for the case when the highest priority SL CAPC is equal to or higher than the predefined CAPC threshold, the highest priority SLCAPC of the SL logical channel (e.g., STCH) in which the MAC SDU is multiplexed in the SL TB is additionally used. For the case when the highest priority SL CAPC is lower than the predefined CAPC threshold, the lowest priority SL CAPC of the SL logical channel (e.g., STCH) in which the MAC SDU is multiplexed in the SL TB is used.

[0109] It should be noted that SBCCH is a channel used to broadcast SL system information from one UE to other UEs. Sidelink Control Channel (SCCH) is a channel used to transmit control information (i.e., PC5-RRC and PC5-S messages) from one UE to other UEs. As used herein, Sidelink Traffic Channel (STCH) refers to a logical channel used to transmit user data from one UE to other UEs.

[0110] It should be noted that Tx UE 402 and / or Rx UE 404 may be provided with different SL communication resources according to different allocation modes. Allocation mode-1 corresponds to an SL communication mode based on NR network scheduling, in which the gNB within the coverage area indicates the resources for SL operation, including resources of one or more resource pools. Allocation mode-2 corresponds to an SL communication mode based on NR UE scheduling (i.e., UE autonomous selection), in which Tx UE 402 and / or Rx UE 404 selects a resource pool and the resources therein from a set of candidate pools. Allocation mode-3 corresponds to an SL communication mode based on LTE network scheduling. Allocation mode-4 corresponds to an SL communication mode based on LTE UE scheduling (i.e., UE autonomous selection).

[0111] As used herein, a "resource pool" refers to a set of resources assigned for sidelink operation. A resource pool consists of a set of resource blocks (i.e., physical resource blocks (PRBs)) within one or more time units (e.g., orthogonal frequency division multiplexing (OFDM) symbols, subframes, time slots, subslots, etc.). In some embodiments, the set of resource blocks includes consecutive PRBs in the frequency domain. As used herein, a PRB consists of twelve consecutive subcarriers in the frequency domain. In certain embodiments, a UE may be configured with a separate transmit resource pool (Tx RP) and receive resource pool (Rx RP), where the Tx RP of one UE is associated with the Rx RP of another UE to enable SL communication.

[0112] According to an embodiment of the second solution, for the case when a TB contains at least a predefined data amount / ratio of a SL logical channel with the highest priority CAPC, the UE uses the highest priority SL CAPC of the SL logical channel in which the MAC SDU is multiplexed in the TB as the CAPC priority of the TB.

[0113] According to one embodiment of the second solution, if the TB does not contain any SL MAC CE or SCCH SDU or SBCCH SDU, then for the case that the TB contains at least a predefined amount / ratio of data of the SL logical channel with the highest priority CAPC, the UE selects the highest priority SL CAPC of the SL logical channel in which the MAC SDU is multiplexed in the TB as the CAPC of the TB. If more than 'x'% of the SL TB is filled with data of the SL logical channel with the highest priority CAPC, then the UE selects the CAPC of the SL TB as the highest priority SL CAPC of the SL logical channel with the MAC SDU.

[0114] The predefined data amount / ratio (i.e., corresponding to 'x' %) may be part of the resource pool configuration parameters. In some embodiments, the predefined data amount may be expressed as an absolute number of bits, bytes, octets, etc. In some embodiments, the predefined data ratio may be expressed as a relative value (e.g., a percentage) relative to the total size of the TB in question at a particular moment in time.

[0115] For example, for transmission, the total size of the TB is 1500 bytes, and the predefined data ratio is 75%. Then, according to the second solution, for the TB / transmission, if the TB contains at least 75% (i.e., 1125 bytes) of data of the SL logical channel with the highest priority CAPC, the UE selects the highest priority CAPC of the SL logical channel in which the MAC SDU is multiplexed in the TB; otherwise, the UE selects the lowest priority CAPC of the SL logical channel in which the MAC SDU is multiplexed in the TB.

[0116] refer to Figure 5 , assuming that the first MAC SDU 502 occupies 65% of the TB, the second MAC SDU 504 occupies 20% of the TB, and the third MAC SDU 506 occupies 15% of the TB. For the above example where the predefined data ratio is 75%, the Tx UE 402 will handle the TB as follows. The highest priority SL CAPC (i.e., the lowest CAPC index / value) of the SL logical channels in which the MAC SDUs are multiplexed in the TB corresponds to CAPC 2 and the first MAC SDU 502. However, since the first MAC SDU 502 occupies less than the predefined ratio / percentage, the Tx UE 402 does not select a CAPC for the TB, and instead selects the lowest priority SL CAPC (i.e., CAPC4 associated with the third MAC SDU 506).

[0117] According to an embodiment of the third solution, the UE determines a data amount / ratio corresponding to a priority equal to or higher than the SL CAPC priority. The UE uses the SL CAPC priority whose data amount / ratio corresponding to a priority equal to or higher than the SL CAPC priority exceeds a predefined amount / ratio as the highest CAPC priority of the TB.

[0118] For example, assume that the first CAPC priority is higher than the second CAPC priority, and the second CAPC priority is higher than the third CAPC priority. Further assume that data corresponding to the first SL CAPC priority occupies 20% of the TB, and data corresponding to the second SL CAPC priority occupies 65% of the TB, and data corresponding to the third SL CAPC priority occupies 15% of the TB. Therefore, data corresponding to the first CAPC priority (i.e., the highest priority, because there is no higher priority data in this example) occupies 20% of the TB, data corresponding to the second CAPC priority (i.e., the next highest priority) occupies 20%+65%=85% of the TB, and data corresponding to the third CAPC priority (i.e., the next higher priority) occupies 20%+65%+15%=100% of the TB.

[0119] Consistent with the above example, if the predefined ratio is 75%, the UE uses the second CAPC priority of the TB because the corresponding 85% exceeds the ratio. However, if the predefined amount is 90%, the UE uses the third CAPC priority in this example (i.e., because the 85% corresponding to the second CAPC priority does not exceed the predefined ratio).

[0120] Apply the third solution to Figure 5, assuming that the first MAC SDU 502 occupies 65% of the TB, the second MAC SDU 504 occupies 20% of the TB, and the third MAC SDU 506 occupies 15% of the TB. For the above example where the predefined data ratio is 75%, the Tx UE 402 will handle the TB as follows. The highest priority SL CAPC (i.e., the lowest CAPC index / value) of the SL logical channel in which the MAC SDUs are multiplexed in the TB corresponds to CAPC 2 and the first MAC SDU 502. However, since the first MAC SDU 502 occupies less than the predefined ratio / percentage, the Tx UE 402 does not select a CAPC for the TB and instead evaluates the next highest priority SL CAPC (i.e., CAPC 3 associated with the second MAC SDU 504). Here, the aggregate data with an SL CAPC index / value of '3' or lower (i.e., having a priority level greater than or equal to CAPC 3) occupies 20%+65%=85% of the TB. Since 85% exceeds the 75% threshold, Tx UE 402 selects SL CAPC 3 for TB.

[0121] According to an embodiment of the fourth solution, the UE is preconfigured with a first set of one or more SL CAPC priorities and an associated first SL CAPC priority. If a TB contains data only from SL logical channels with MAC SDUs corresponding to any SL CAPC priority in the first set, the UE uses the associated first SL CAPC priority of the TB.

[0122] For example, assume that the first group contains the first CAPC priority and the second CAPC priority. According to the fourth solution, if the data with the TB consists only of data from SL logical channels corresponding to the first or second CAPC priority, the UE uses the first associated CAPC priority of the TB.

[0123] According to an embodiment of the fifth solution, the UE uses the SL CAPC priority of the SL logical channel in which the MAC SDU is multiplexed in the TB occupying the highest ratio of the total TB size as the CAPC priority of the TB.

[0124] For example, if data corresponding to a first SL CAPC priority level occupies 20% of a TB, and data corresponding to a second SL CAPC priority level occupies 65% of a TB, and data corresponding to a third SL CAPC priority level occupies 15% of a TB, then the UE uses the second SL CAPC priority level as the priority level for the TB. For situations where the amount / ratio of data is the same for more than one SL CAPC priority level, it may be up to the UE implementation to select which SL CAPC priority level to use for the TB.

[0125] According to an embodiment of the sixth solution, when a MAC PDU contains a MAC SDU and / or MAC CE of a SL logical channel (e.g., STCH or SCCH or SBCCH) with the highest CAPC - even if there is data of such SL logical channel available for transmission in the UE buffer, the UE is allowed not to multiplex the MAC SDU of a SL logical channel (e.g., STCH) with a lower CAPC into the MAC PDU. According to this solution, in order to avoid the UE having to select / use a low CAPC to transmit a SL MAC PDU carrying high priority data (e.g., SCCH / SBCCH MAC SDU or MAC CE) (because the data of the SL logical channel with a low CAPC is also multiplexed within this MAC PDU), the UE is allowed to multiplex a padding PDU instead of the data of the SL LCH with a low CAPC into the MAC PDU.

[0126] According to a specific implementation of the sixth solution, the UE will only be allowed to multiplex fill into the MAC PDU when the amount of data with the highest CAPC within the MAC PDU exceeds a certain configured size threshold (e.g., value or percentage). Such size threshold can be configured by higher layer signaling.

[0127] According to another implementation of the sixth solution, in case the MAC PDU contains data (e.g. SL MAC CE or STCH / SCCH / SBCCH) of the SL LCH with the highest CAPC (i.e. lowest signaled value = 1), the UE shall not multiplex the MAC SDU of the SL LCH with a CAPC lower than the configured CAPC threshold. The UE is configured with this CAPC threshold, for example, through RRC signaling.

[0128] During the Logical Channel Priority (LCP) procedure or the Resource Allocation procedure (Mode 2), i.e., when generating the SL MAC PDU, the UE checks whether the SL LCH is allowed to multiplex data within the MAC PDU depending on the CAPC configured / specified for the SL LCH. For the case when the data of the LCH with the highest CAPC or SL MAC CE is multiplexed in the MAC PDU, the UE shall not multiplex the data of other SL LCHs with a CAPC priority lower than the configured CAPC priority threshold in the MAC PDU.

[0129] According to an embodiment of the seventh solution, if there is data with the highest priority CAPC contained in the TB, that is, the highest priority CAPC=1, then the UE uses the highest priority CAPC for the SL TB. According to an implementation of the seventh solution, such data may be SL MAC CE or SCCH MAC SDU or SBCCH MAC SDU or STCH MAC SDU. According to the seventh solution, in order to ensure that for the case where the SL TB includes data with the highest priority CAPC, no matter what other data is multiplexed in the SL TB, the UE uses the highest priority CAPC for the transmission of the SL TB.

[0130] According to an embodiment of the eighth solution, for situations where the CAPC determined for the SL TB cannot satisfy the PDB requirements of the TB, the UE may remove or exclude one or more MAC SDUs from the SL TB. For example, the LBT process—including the contention window determined based on the CAPC—may not be able to meet the conditions that allow transmission before the PDB expires. If the required minimum total channel access sensing duration extends beyond the PDB of the TB, this may be known at the initialization step of the channel access process.

[0131] Therefore, in order to be able to meet the PDB requirement, the UE may remove data from the SL LCH with the lowest priority CAPC so as to increase the CAPC priority associated with the SL TB. For example, the UE may add padding to fill the TB size after removing the low CAPC priority data.

[0132] According to an alternative implementation of the eighth solution, the UE does not include the highest priority CAPC data in the TB and instead triggers a scheduling request (SR) on Uu to request SL resources for high priority CAPC data from the gNB. In such an embodiment, the gNB may signal the CAPC value in the SL DCI, which the UE needs to apply for the corresponding SL transmission.

[0133] According to an embodiment of the ninth solution, there may be a weighted average calculation to derive the final CAPC based on the weight coefficient of each data type (e.g., very high weights for certain MAC CE / SCCH SDUs and / or SBCCH SDUs, and lower weights for other MAC CE / SCCH SDUs and / or SBCCH SDUs and data LCHs).

[0134] Assume that there are N multiplexed into one TB d data type, the calculation can be completed according to the following equation:

[0135]

[0136] where w t is the weight coefficient of data type t, and p t is the CAPC priority level associated with data type t. The result of this formula may be rounded (eg, up or down) to an integer CAPC priority level.

[0137] According to the implementation scheme of the ninth solution, the weight coefficient w t It can be configured as a parameter for each data type, for example, very high weight for some MAC CE / SCCH SDU and / or SBCCH SDU, and lower weight for other MAC CE / SCCH SDU and / or SBCCH SDU and data LCH. This configuration can be part of the resource pool configuration.

[0138] According to an embodiment of the tenth solution, there may be a weighted average calculation to derive the final CAPC. Assuming four CAPC priority levels, the calculation may be done according to the following equation:

[0139]

[0140] where w p is the weight coefficient p of the CAPC priority level. The result of this formula may be rounded (e.g., up or down) to reach an integer CAPC priority level. According to an embodiment of the tenth solution, the weight coefficient w p Can be configured as a parameter for each CAPC priority class. This configuration can be part of the resource pool configuration.

[0141] Figure 6 An example of a UE 600 according to aspects of the present disclosure is illustrated. The UE 600 may include a processor 602, a memory 604, a controller 606, and a transceiver 608. The processor 602, the memory 604, the controller 606, or the transceiver 608, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled via one or more interfaces (e.g., operatively, communicatively, functionally, electronically, electrically).

[0142] The processor 602, memory 604, controller 606, or transceiver 608, or various combinations or components thereof may be implemented in hardware (e.g., circuitry). The hardware may include a processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), or other programmable logic device, or any combination thereof that is configured or otherwise supports means for performing the functions described in the present disclosure.

[0143] The processor 602 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a CPU, an ASIC, a field programmable gate array (FPGA), or any combination thereof). In some implementations, the processor 602 may be configured to operate the memory 604. In some other implementations, the memory 604 may be integrated into the processor 602. The processor 602 may be configured to execute computer-readable instructions stored in the memory 604 to enable the UE 600 to perform various functions of the present disclosure.

[0144] Memory 604 may include volatile or non-volatile memory. Memory 604 may store computer-readable, computer-executable code, which includes instructions that, when executed by processor 602, cause UE 600 to perform various functions described herein. Code may be stored in a non-transitory computer-readable medium, such as memory 604 or another type of memory. Computer-readable media include both non-transitory computer storage media and communication media, including any media that facilitates the transfer of computer programs from one place to another. Non-transitory storage media may be any available media that can be accessed by a general or special purpose computer.

[0145] In some implementations, the processor 602 and the memory 604 coupled to the processor 602 may be configured to cause the UE 600 to perform one or more of the UE functions described herein (e.g., the processor 602 executes instructions stored in the memory 604). For example, the processor 602 may support wireless communications at the UE 600 according to the examples disclosed herein. The UE 600 may be configured to support means for generating a SL TB to be transmitted to a group of Rx UEs through a SL channel, wherein the SL TB includes data units associated with a plurality of SL LCHs, each SL LCH being associated with a corresponding CAPC.

[0146] In some embodiments, the respective CAPC is based at least in part on a delay requirement (eg, PDB) of the corresponding SL LCH. In some embodiments, the plurality of SL LCHs comprises at least one STCH. In some embodiments, the data unit comprises a MAC SDU.

[0147] UE 600 may be configured to support means for determining a highest priority CAPC associated with a SL TB.UE 600 may be configured to support means for selecting a CAPC value for a SL TB based at least in part on the highest priority CAPC satisfying a threshold.

[0148] In some embodiments, to select a CAPC value, the UE 600 may be configured to select a highest priority CAPC in response to the highest priority CAPC satisfying a threshold. In certain embodiments, to select a CAPC value, the UE 600 may be configured to select a lowest priority CAPC in response to the highest priority CAPC not satisfying a threshold, wherein the lowest priority CAPC is associated with a longer contention window (CW) than the highest priority CAPC.

[0149] In some embodiments, to select a CAPC value, the UE is further configured to select a CAPC value based at least in part on an amount of data associated with a highest priority CAPC satisfying a predetermined amount. In some embodiments, to select a CAPC value, the UE is further configured to select a CAPC value based at least in part on a ratio of data associated with a highest priority CAPC satisfying a predetermined ratio.

[0150] The UE 600 may be configured to support means for performing an LBT process using a set of LBT parameters corresponding to the selected CAPC value. In some implementations, the UE 600 may be further configured to remove one or more data units from the SL TB in response to the selected CAPC not satisfying a packet delay budget associated with one of the multiple SL LCHs.

[0151] The UE 600 may be configured to support means for transmitting SLTB over a SL channel based at least in part on the success of the LBT process. In some implementations, the UE 600 may be configured to initiate SL communications with the set of Rx UEs on an unlicensed band (i.e., in a shared spectrum), wherein the SL communications correspond to one or more SL LCHs.

[0152] In some embodiments, to initiate SL communication, UE 600 may be configured to select a SL grant, wherein the SL grant fails to indicate a CAPC value for the corresponding SL transmission. In some embodiments, UE 600 may be further configured to: A) perform a sensing process associated with an unlicensed band; and B) determine available SL resources for SL communication based at least in part on the results of the sensing process.

[0153] The controller 606 may manage input and output signals of the UE 600. The controller 606 may also manage peripheral devices that are not integrated into the UE 600. In some embodiments, the controller 606 may utilize an operating system (OS), such as Or other operating system (OS). In some implementations, controller 606 may be implemented as part of processor 602.

[0154] In some implementations, the UE 600 may include at least one transceiver 608. In some other implementations, the UE 600 may have more than one transceiver 608. The transceiver 608 may represent a wireless transceiver. The transceiver 608 may include one or more receiver chains 610, one or more transmitter chains 612, or a combination thereof.

[0155] The receiver chain 610 may be configured to receive a signal (e.g., control information, data, packet) over a wireless medium. For example, the receiver chain 610 may include one or more antennas for receiving signals over the air or wireless medium. The receiver chain 610 may include at least one amplifier (e.g., a low noise amplifier (LNA)) configured to amplify the received signal. The receiver chain 610 may include at least one demodulator configured to demodulate the received signal and obtain the transmitted data by inverting the modulation technique applied during the transmission of the signal. The receiver chain 610 may include at least one decoder for decoding and processing the demodulated signal to receive the transmitted data.

[0156] The transmitter chain 612 may be configured to generate and transmit signals (e.g., control information, data, packets). The transmitter chain 612 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques, such as amplitude modulation (AM), frequency modulation (FM), or a digital modulation scheme such as phase shift keying (PSK) or quadrature amplitude modulation (QAM). The transmitter chain 612 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over a wireless medium. The transmitter chain 612 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

[0157] Figure 7 An example of a processor 700 according to aspects of the present disclosure is illustrated. The processor 700 may be an example of a processor configured to perform various operations according to examples as described herein. The processor 700 may include a controller 702 configured to perform various operations according to examples as described herein. The processor 700 may optionally include at least one memory 704, which may be, for example, an L1 / L2 / L3 cache. Additionally or alternatively, the processor 700 may optionally include one or more arithmetic logic units (ALUs) 706. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., a bus).

[0158] The processor 700 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receive, obtain, retrieve, transmit, output, forward, store, determine, identify, access, write, read) according to the examples described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., processor 700) or other memory (e.g., random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), static RAM (SRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, phase change memory (PCM), etc.)).

[0159] The controller 702 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 700 so that the processor 700 supports various operations according to examples as described herein. For example, the controller 702 may operate as a control unit for the processor 700, generating control signals that manage the operation of various components of the processor 700. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating the timing of operations.

[0160] The controller 702 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 704 and determine subsequent instructions to be executed to enable the processor 700 to support various operations according to the examples as described herein. The controller 702 may be configured to track the memory addresses of instructions associated with the memory 704. The controller 702 may be configured to decode the instructions to determine the operations to be performed and the operands involved. For example, the controller 702 may be configured to interpret the instructions and determine control signals to be output to other components of the processor 700 to enable the processor 700 to support various operations according to the examples as described herein. In addition or alternatively, the controller 702 may be configured to manage the data flow within the processor 700. The controller 702 may be configured to control the transfer of data between registers, arithmetic logic units (ALUs), and other functional units of the processor 700.

[0161] The memory 704 may include one or more caches (e.g., memory local to or included in the processor 700 or other memory such as RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc.). In some implementations, the memory 704 may reside within or on a processor chipset (e.g., local to the processor 700). In some other implementations, the memory 704 may reside external to the processor chipset (e.g., remote from the processor 700).

[0162] The memory 704 may store computer-readable, computer-executable code, which includes instructions that, when executed by the processor 700, cause the processor 700 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium, such as a system memory or another type of memory. The controller 702 and / or the processor 700 may be configured to execute computer-readable instructions stored in the memory 704 to cause the processor 700 to perform various functions. For example, the processor 700 and / or the controller 702 may be coupled to or coupled to the memory 704, and the processor 700, the controller 702, and the memory 704 may be configured to perform various functions described herein. In some examples, the processor 700 may include multiple processors, and the memory 704 may include multiple memories. One or more of the multiple processors may be coupled to one or more of the multiple memories, and the multiple memories may be individually or collectively configured to perform various functions described herein.

[0163] The one or more ALUs 706 may be configured to support various operations according to the examples as described herein. In some embodiments, the one or more ALUs 706 may reside within or on a processor chipset (e.g., processor 700). In some other embodiments, the one or more ALUs 706 may reside outside a processor chipset (e.g., processor 700). The one or more ALUs 706 may perform one or more calculations on data, such as addition, subtraction, multiplication, and division. For example, the one or more ALUs 706 may receive input operands and an operation code that determines the operation to be performed. The one or more ALUs 706 may be configured with various logic and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate data according to the operation. Additionally or alternatively, the one or more ALUs 706 may support logical operations such as AND, OR, XOR, NOR, and NAND, enabling the one or more ALUs 706 to handle conditional operations, comparisons, and bitwise operations.

[0164] The processor 700 may support wireless communications according to examples as disclosed herein. For example, the processor 700 may perform one or more of the UE functions described herein. The processor 700 may be configured or operable to support a component for generating a SL TB to be transmitted to a group of Rx UEs on a SL channel, wherein the SL TB includes data units associated with multiple SL LCHs, each SL LCH being associated with a corresponding CAPC.

[0165] In some embodiments, the respective CAPC is based at least in part on a delay requirement (eg, PDB) of the corresponding SL LCH. In some embodiments, the plurality of SL LCHs comprises at least one STCH. In some embodiments, the data unit comprises a MAC SDU.

[0166] Processor 700 may be configured to support means for determining a highest priority CAPC associated with a SL TB. Processor 700 may be configured to support means for selecting a CAPC value for the SL TB based at least in part on the highest priority CAPC satisfying a threshold.

[0167] In some embodiments, to select a CAPC value, the processor 700 may be configured to select a highest priority CAPC in response to the highest priority CAPC satisfying a threshold. In certain embodiments, to select a CAPC value, the processor 700 may be configured to select a lowest priority CAPC in response to the highest priority CAPC not satisfying a threshold, wherein the lowest priority CAPC is associated with a longer contention window (CW) than the highest priority CAPC.

[0168] In some embodiments, to select a CAPC value, the UE is further configured to select a CAPC value based at least in part on an amount of data associated with a highest priority CAPC satisfying a predetermined amount. In some embodiments, to select a CAPC value, the UE is further configured to select a CAPC value based at least in part on a ratio of data associated with a highest priority CAPC satisfying a predetermined ratio.

[0169] The processor 700 may be configured to support means for performing an LBT process using a set of LBT parameters corresponding to the selected CAPC value. In some implementations, the processor 700 may be further configured to remove one or more data units from the SL TB in response to the selected CAPC not satisfying a packet delay budget associated with one of the plurality of SL LCHs.

[0170] The processor 700 may be configured to support means for transmitting a SL TB over a SL channel based at least in part on the success of the LBT process. In some implementations, the processor 700 may be configured to initiate SL communications with the set of Rx UEs on an unlicensed band (i.e., in a shared spectrum), wherein the SL communications correspond to one or more SL LCHs.

[0171] In some embodiments, to initiate SL communication, the processor 700 may be configured to select a SL grant, wherein the SL grant fails to indicate a CAPC value for the corresponding SL transmission. In some embodiments, the processor 700 may be further configured to: A) perform a sensing process associated with the unlicensed band; and B) determine available SL resources for SL communication based at least in part on a result of the sensing process.

[0172] Figure 8 An example of a NE 800 according to aspects of the present disclosure is illustrated. The NE 800 may include a processor 802, a memory 804, a controller 806, and a transceiver 808. The processor 802, the memory 804, the controller 806, or the transceiver 808, or various combinations thereof, or various components thereof, may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled via one or more interfaces (e.g., operatively, communicatively, functionally, electronically, electrically).

[0173] The processor 802, memory 804, controller 806, or transceiver 808, or various combinations or components thereof, may be implemented in hardware (e.g., circuitry). The hardware may include a processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), or other programmable logic device, or any combination thereof that is configured or otherwise supports means for performing the functions described in the present disclosure.

[0174] The processor 802 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof). In some embodiments, the processor 802 may be configured to operate the memory 804. In some other embodiments, the memory 804 may be integrated into the processor 802. The processor 802 may be configured to execute computer-readable instructions stored in the memory 804 to enable the NE 800 to perform various functions of the present disclosure.

[0175] Memory 804 may include volatile or non-volatile memory. Memory 804 may store computer-readable, computer-executable code, which includes instructions that, when executed by processor 802, cause NE 800 to perform various functions described herein. Code may be stored in a non-transitory computer-readable medium, such as memory 804 or another type of memory. Computer-readable media include both non-transitory computer storage media and communication media, including any media that facilitates the transfer of computer programs from one place to another. Non-transitory storage media may be any available media that can be accessed by a general or special purpose computer.

[0176] In some embodiments, the processor 802 and the memory 804 coupled to the processor 802 may be configured to cause the NE 800 to perform one or more of the functions described herein (e.g., the processor 802 executes instructions stored in the memory 804). For example, the processor 802 may support wireless communications at the NE 800 according to the examples disclosed herein. The NE 800 may be configured to support means for configuring a CAPC threshold for SL operation for one or more UEs.

[0177] In some embodiments, the NE 800 may be configured to support means for configuring a resource pool configuration parameter for a UE indicating the amount and / or ratio of data for CAPC selection during SL operation. In some embodiments, the NE 800 may be configured to support means for configuring a first set (one or more) of SL CAPC priorities and an associated first SL CAPC priority for a UE.

[0178] In some embodiments, NE 800 may be configured to support means for configuring MAC PDU size thresholds for CAPC selection during SL operation for UE. In some embodiments, NE 800 may be configured to support means for configuring weight coefficients for one or more data types for CAPC selection during SL operation for UE.

[0179] Controller 806 can manage input and output signals of NE 800. Controller 806 can also manage peripheral devices that are not integrated into NE 800. In some embodiments, controller 806 can utilize OS, such as Or other OS. In some implementations, controller 806 may be implemented as part of processor 802.

[0180] In some implementations, NE 800 may include at least one transceiver 808. In some other implementations, NE 800 may have more than one transceiver 808. Transceiver 808 may represent a wireless transceiver. Transceiver 808 may include one or more receiver chains 810, one or more transmitter chains 812, or a combination thereof.

[0181] The receiver chain 810 may be configured to receive a signal (e.g., control information, data, packet) over a wireless medium. For example, the receiver chain 810 may include one or more antennas for receiving signals over the air or wireless medium. The receiver chain 810 may include at least one amplifier (e.g., a low noise amplifier (LNA)) configured to amplify the received signal. The receiver chain 810 may include at least one demodulator configured to demodulate the received signal and obtain the transmitted data by inverting the modulation technique applied during the transmission of the signal. The receiver chain 810 may include at least one decoder for decoding and processing the demodulated signal to receive the transmitted data.

[0182] The transmitter chain 812 may be configured to generate and transmit signals (e.g., control information, data, packets). The transmitter chain 812 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques, such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes such as phase shift keying (PSK) or quadrature amplitude modulation (QAM). The transmitter chain 812 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over a wireless medium. The transmitter chain 812 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

[0183] Fig. 9 Flowchart illustrating a method 900 according to aspects of the present disclosure. The operations of the method 900 may be performed by a UE as described herein. In some embodiments, the UE may execute a set of instructions to control functional elements of the UE to perform the described functions.

[0184] At step 902, method 900 may include generating a SL TB to be transmitted to a group of Rx UEs. Here, the SL TB includes data units associated with multiple SL LCHs. The operations of step 902 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 902 may be performed by a UE, as described in reference to Figure 6 described.

[0185] At step 904, method 900 may include determining a highest priority CAPC associated with the SL TB, wherein each SLLCH is associated with a corresponding CAPC. The operations of step 904 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 904 may be performed by a UE, as described in reference to Figure 6 described.

[0186] At step 906, method 900 may include selecting a CAPC value for the SLTB based at least in part on the highest priority CAPC satisfying a threshold. The operations of step 906 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 906 may be performed by a UE, as described in reference to Figure 6 described.

[0187] At step 908, method 900 may include performing an LBT process using a set of LBT parameters corresponding to the selected CAPC value. The operations of step 908 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 908 may be performed by a UE, as described in reference to Figure 6 described.

[0188] At step 910, method 900 may include transmitting a SL TB based at least in part on the success of the LBT process. The operations of step 910 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 910 may be performed by a UE, as described in reference to Figure 6 described.

[0189] It should be noted that the method 900 described herein describes one possible implementation, and that the operations and steps may be rearranged or otherwise modified, and other implementations are possible.

[0190] Fig.10 Flowchart illustrating a method 1000 according to aspects of the present disclosure. The operations of the method 1000 may be performed by a UE as described herein. In some embodiments, the UE may execute a set of instructions to control functional elements of the UE to perform the described functions.

[0191] At step 1002, method 1000 may include generating a SL TB to be transmitted to a group of Rx UEs, wherein the SL TB includes data units associated with multiple SL LCHs. The operations of step 1002 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1002 may be performed by a UE, as described in reference to Figure 6 described.

[0192] At step 1004, method 1000 may include determining a highest priority CAPC associated with a SL TB, wherein each SL LCH is associated with a corresponding CAPC. The operations of step 1004 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1004 may be performed by a UE, as described in reference to Figure 6 described.

[0193] At step 1006, method 1000 may include determining whether the highest priority CAPC satisfies a priority threshold. The operations of step 1006 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1006 may be performed by a UE, as described in reference to Figure 6 described.

[0194] At step 1008, method 1000 may include selecting a CAPC value corresponding to the highest priority CAPC when the highest priority CAPC satisfies the priority threshold. The operations of step 1008 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1008 may be performed by a UE, as described in reference to Figure 6 described.

[0195] At step 1010, method 1000 may include selecting a CAPC value corresponding to a lowest priority CAPC when the highest CAPC does not satisfy the priority threshold. The operations of step 1010 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1010 may be performed by a UE, as described in reference to Figure 6 described.

[0196] At step 1012, method 1000 may include performing an LBT process using a set of LBT parameters corresponding to the selected CAPC value. The operations of step 1012 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1012 may be performed by a UE, as described in reference to Figure 6 described.

[0197] At step 1014, method 1000 may include transmitting a SL TB based at least in part on the success of the LBT process. The operations of step 1014 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1014 may be performed by a UE, as described in reference to Figure 6 described.

[0198] It should be noted that the method 1000 described herein describes one possible implementation, and that the operations and steps may be rearranged or otherwise modified, and other implementations are possible.

[0199] Fig.11Flowchart illustrating a method 1100 according to aspects of the present disclosure. The operations of the method 1100 may be performed by a UE as described herein. In some embodiments, the UE may execute a set of instructions to control functional elements of the UE to perform the described functions.

[0200] At step 1102, method 1100 may include generating a SL TB to be transmitted to a group of Rx UEs, wherein the SL TB includes data units associated with multiple SL LCHs. The operations of step 1102 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1102 may be performed by a UE, as described in reference to Figure 6 described.

[0201] At step 1104, method 1100 may include determining a highest priority CAPC associated with the SL TB, wherein each SL LCH is associated with a corresponding CAPC. The operations of step 1104 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1104 may be performed by a UE, as described in reference to Figure 6 described.

[0202] At step 1106, method 1100 may include determining whether the data ratio or amount in the SL TB associated with the highest priority CAPC satisfies the priority threshold. The operations of step 1106 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1106 may be performed by a UE, as described in reference to Figure 6 described.

[0203] At step 1108, method 1100 may include determining whether the data ratio or amount associated with the highest priority CAPC satisfies the priority threshold. The operations of step 1108 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1108 may be performed by a UE, as described in reference to Figure 6 described.

[0204] At step 1110, method 1100 may include selecting a CAPC value corresponding to a highest priority CAPC when the data ratio or amount satisfies a priority threshold. The operations of step 1110 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1110 may be performed by a UE, as described in reference to Figure 6 described.

[0205] At step 1112, method 1100 may include selecting a CAPC value corresponding to a lowest priority CAPC when the data ratio or amount does not satisfy the priority threshold. The operations of step 1112 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1112 may be performed by a UE, as described in reference to Figure 6 described.

[0206] At step 1114, method 1100 may include performing an LBT process using a set of LBT parameters corresponding to the selected CAPC value. The operations of step 1114 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1114 may be performed by a UE, as described in reference to Figure 6 described.

[0207] At step 1116, method 1100 may include transmitting a SL TB based at least in part on the success of the LBT process. The operations of step 1116 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1116 may be performed by a UE, as described in reference to Figure 6 described.

[0208] It should be noted that the method 1100 described herein describes one possible implementation, and that the operations and steps may be rearranged or otherwise modified, and other implementations are possible.

[0209] Fig.12 Flowchart illustrating a method 1200 according to aspects of the present disclosure. The operations of the method 1200 may be performed by a UE as described herein. In some embodiments, the UE may execute a set of instructions to control functional elements of the UE to perform the described functions.

[0210] At step 1202, method 1200 may include performing a sensing process associated with an unlicensed band (i.e., a radio band in a shared spectrum). The operations of step 1202 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1202 may be performed by a UE, as described in reference to Figure 6 described.

[0211] At step 1204, method 1200 may include determining available SL resources for SL communication based at least in part on the results of the sensing process. The operations of step 1204 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1204 may be performed by a UE, as described in reference to Figure 6 described.

[0212] At step 1206, method 1200 may include selecting a SL grant, wherein the SL grant fails to indicate a CAPC value for the corresponding SL transmission. The operations of step 1206 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1206 may be performed by a UE, as described in reference to Figure 6 described.

[0213] At step 1208, method 1200 may include initiating SL communications with a set of Rx UEs, wherein the SL communications correspond to one or more SL LCHs, wherein each SL LCH is associated with a corresponding CAPC. The operations of step 1208 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1208 may be performed by a UE, as described in reference to Figure 6 described.

[0214] At step 1210, method 1200 may include selecting a CAPC value for the SL TB, i.e., according to one or more of the aspects described above. The operations of step 1210 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1210 may be performed by a UE, as described in reference to Figure 6 described.

[0215] At step 1212, method 1200 may include performing an LBT process using a set of LBT parameters corresponding to the selected CAPC value. The operations of step 1212 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1212 may be performed by a UE, as described in reference to Figure 6 described.

[0216] It should be noted that the method 1200 described herein describes one possible implementation, and that the operations and steps may be rearranged or otherwise modified, and other implementations are possible.

[0217] Fig.13 Flowchart illustrating a method 1300 according to aspects of the present disclosure. The operations of the method 1300 may be performed by a UE as described herein. In some embodiments, the UE may execute a set of instructions to control functional elements of the UE to perform the described functions.

[0218] At step 1302, method 1300 may include generating a SL TB to be transmitted to a group of Rx UEs, wherein the SL TB includes data units associated with multiple SL LCHs. The operations of step 1302 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1302 may be performed by a UE, as described in reference to Figure 6 described.

[0219] At step 1304, method 1300 may include selecting a CAPC value for the SL TB, i.e., according to one or more of the aspects described above. The operations of step 1304 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1304 may be performed by a UE, as described in reference to Figure 6 described.

[0220] At step 1306, method 1300 may include determining whether the selected CAPC value satisfies one or more PDBs associated with the SL TB. The operations of step 1306 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1306 may be performed by a UE, as described in reference to Figure 6 described.

[0221] At step 1308, method 1300 may include removing one or more lower priority data units from the SL TB when the selected CAPC value does not satisfy the PDB associated with the SL TB. The operations of step 1308 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1308 may be performed by a UE, as described in reference to Figure 6 described.

[0222] At step 1310, method 1000 may include performing an LBT process using a set of LBT parameters corresponding to the selected CAPC value. The operations of step 1310 may be performed according to examples as described herein. In some embodiments, aspects of the operations of step 1310 may be performed by a UE, as described in reference to Figure 6 described.

[0223] At step 1312, method 1000 may include transmitting a SL TB based at least in part on the success of the LBT process. The operations of step 1312 may be performed according to examples as described herein. In some implementations, aspects of the operations of step 1312 may be performed by a UE, as described in reference to Figure 6 described.

[0224] It should be noted that the method 1300 described herein describes one possible implementation, and that the operations and steps may be rearranged or otherwise modified, and other implementations are possible.

[0225] The description herein is provided to enable one of ordinary skill in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to one of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A user equipment UE for wireless communication, comprising: at least one memory; and at least one processor coupled to the at least one memory and configured to cause the UE to: generating a sidelink SL transport block TB to be transmitted to a group of receiving UEs Rx UE, wherein the SL TB comprises data units associated with a plurality of SL logical channels LCH, each SL LCH being associated with a respective channel access priority class CAPC; determining a highest priority CAPC associated with the SL TB; selecting a CAPC value for the SL TB based at least in part on the highest priority CAPC satisfying a threshold; performing a listen-before-talk (LBT) process using a set of LBT parameters corresponding to the selected CAPC value; and The SL TB is transmitted based at least in part on the success of the LBT process.

2. The UE of claim 1, wherein to select the CAPC value, the at least one processor is configured to cause the UE to select the highest priority CAPC in response to the highest priority CAPC satisfying the threshold.

3. The UE of claim 2, wherein to select the CAPC value, the at least one processor is configured to cause the UE to select a lowest priority CAPC in response to the highest priority CAPC not satisfying the threshold, wherein the lowest priority CAPC is associated with a longer contention window (CW) than the highest priority CAPC.

4. The UE of claim 1 , wherein to select the CAPC value, the at least one processor is configured to cause the UE to further select the CAPC value based at least in part on an amount or ratio of data associated with the highest priority CAPC satisfying a predetermined amount or a predetermined ratio.

5. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to initiate SL communication with the set of Rx UEs on an unlicensed band, and wherein the SL communication corresponds to the one or more SLLCHs.

6. The UE of claim 5, wherein to initiate the SL communication, the at least one processor is configured to cause the UE to select a SL grant, wherein the SL grant fails to indicate a CAPC value for a corresponding SL transmission.

7. The UE of claim 5, wherein to initiate the SL communication, the at least one processor is configured to cause the UE to: performing a sensing process associated with the unauthorized band; and Available SL resources for the SL communication are determined based at least in part on results of the sensing process.

8. The UE according to claim 1, wherein the plurality of SL LCHs include at least one SL service channel (STCH).

9. The UE of claim 1, wherein the corresponding CAPC is based at least in part on a delay requirement of a corresponding SL LCH.

10. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to remove one or more data units from the SL TB in response to the selected CAPC not satisfying a packet delay budget associated with one of the plurality of SL LCHs, wherein the data units comprise medium access control MAC service data units (SDUs).

11. A processor for wireless communication, comprising: at least one controller coupled to at least one memory and configured to cause the processor to: generating a sidelink SL transport block TB to be transmitted to a group of receiving UEs Rx UE, wherein the SL TB comprises data units associated with a plurality of SL logical channels LCH, each SL LCH being associated with a respective channel access priority class CAPC; determining a highest priority CAPC associated with the SL TB; selecting a CAPC value for the SL TB based at least in part on the highest priority CAPC satisfying a threshold; performing a listen-before-talk (LBT) process using a set of LBT parameters corresponding to the selected CAPC value; and The SL TB is transmitted based at least in part on the success of the LBT process.

12. The processor of claim 11, wherein to select the CAPC value, the at least one controller is configured to cause the processor to select the highest priority CAPC in response to the highest priority CAPC satisfying the threshold.

13. The processor of claim 12, wherein to select the CAPC value, the at least one controller is configured to cause the processor to select a lowest priority CAPC in response to the highest priority CAPC not satisfying the threshold, wherein the lowest priority CAPC is associated with a longer contention window (CW) than the highest priority CAPC.

14. The processor of claim 11, wherein to select the CAPC value, the at least one controller is configured to cause the processor to further select the CAPC value based at least in part on an amount or ratio of data associated with the highest priority CAPC satisfying a predetermined amount or a predetermined ratio.

15. The processor of claim 11, wherein the at least one controller is configured to cause the processor to initiate SL communication with the set of Rx UEs on an unlicensed band, and wherein the SL communication corresponds to the one or more SL LCHs.

16. The processor of claim 15, wherein to initiate the SL communication, the at least one controller is configured to cause the processor to select a SL grant, wherein the SL grant fails to indicate a CAPC value for a corresponding SL transmission.

17. The processor of claim 15, wherein to initiate the SL communication, the at least one controller is configured to cause the processor to: performing a sensing process associated with the unauthorized band; and Available SL resources for the SL communication are determined based at least in part on results of the sensing process.

18. The processor of claim 11, wherein the plurality of SL LCHs include at least one SL traffic channel (STCH).

19. The processor of claim 11, wherein the respective CAPC is based at least in part on a delay requirement of a corresponding SLLCH.

20. The processor of claim 11, wherein the at least one controller is further configured to cause the processor to remove one or more data units from the SL TB in response to the selected CAPC not satisfying a packet delay budget associated with one of the plurality of SL LCHs, wherein the data units comprise medium access control (MAC) service data units (SDUs).

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