Pre-emption resource reselection

Abstract

A wireless transmit / receive unit (WTRU) may determine a set of carriers and an overlapping duration threshold. The WTRU may transmit a first physical sidelink control channel (PSCCH) and / or physical sidelink shared channel (PSSCH) transmission to reserve a PSCCH and / or PSSCH resource. The WTRU may perform a pre-emption checking of the reserved PSCCH and / or PSSCH resource.

Description

PRE-EMPTION RESOURCE RESELECTIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 531 ,120 filed on August 7, 2023, the entire contents of which are incorporated herein by reference.BACKGROUND

[0002] Long term evolution (LTE) vehicle-to-everything (V2X) may support one subcarrier spacing (SCS) of 15 KHz for all carriers. For carrier aggregation, all the aggregated carriers may have the same synchronization configuration. All the aggregated carriers may be synchronized.

[0003] Multicarrier may currently be specified for new radio (NR) sidelink (SL). Multicarrier may be expected to use LTE as a baseline, while potentially considering some differences to account for unicast transmission in NR. Many restrictions in configuration may be imposed to simplify the design. For example, the imposed restrictions in configuration may include the same configuration of SCS, physical sidelink feedback channel (PSFCH), and / or sidelink synchronization signal block (S-SSB) across all carriers.

[0004] Multicarrier operation in NR sidelink evolution (SLE) may need to consider different transmission duration of various transmission channels (e.g., physical sidelink control channel (PSCCH) and / or physical sidelink shared channel (PSSCH) and / or physical sidelink feedback channel (PSFCH)) and / or the same channel in different carriers with different SCSs. NR SLE may also aggregate multiple carriers with various synchronization configurations due to operation band and / or the desired latency of packet delivery (e.g., the network may configure a larger SCS for targeting the lower latency requirement services).SUMMARY

[0005] A first wireless transmit / receive unit may determine a set of carriers and an overlapping duration threshold. The WTRU may transmit a first physical sidelink control channel (PSCCH) or physical sidelink shared channel (PSSCH) transmission to reserve a PSCCH and / or PSSCH resource. The WTRU may perform a pre-emption checking of the reserved PSCCH or PSSCH resource. The WTRU may select one or more hybrid automatic repeat request (HARQ) disabled logical channels (LCHs) to multiplex a transport block (TB) to transmit in the PSCCH and / or PSSCH resource when the associated physical sidelink feedback channel (PSFCH) overlaps and / or has different starting and / or ending symbols than the reserved PSCCH and / or PSSCH and / or an associated PSFCH of a second WTRU. The second WTRU may use a carrier different that the carrier from the first WTRU. The WTRU may select a different PSCCH and / orPSSCH resource when the reserved PSCCH and / or PSSCH resource and / or the associated PSFCH overlaps and / or has different starting and / or ending symbols than the reserved PSCCH and / or PSSCH or an associated PSFCH from the second WTRU. The WTRU may puncture and / or rate-match during an overlap duration based on the reserved PSCCH and / or PSSCH resource or the associated PSFCH overlaps and / or has different starting and / or ending symbols than the reserved PSCCH and / or PSSCH and / or an associated PSFCH from the second WTRU.

[0006] The pre-emption checking may comprise selecting the different PSCCH and / or PSSCH resource. The pre-emption checking may comprise transmitting a second PSSCH and / or PSCCH transmission in the different PSCCH and / or PSSCH resource.

[0007] The pre-emption checking may comprise selecting the different PSCCH and / or PSSCH resource based on the overlap duration being greater than the overlapping duration threshold.

[0008] The pre-emption checking may comprise puncturing and / or rate-matching during the overlap duration based on the overlap duration being less than the overlapping duration threshold.

[0009] The WTRU may determine a resource allocation carrier from the set of carriers. The resource allocation carrier may include a subset of carriers for collaborative sensing. The WTRU may perform collaborative sensing on the subset of carriers for collaborative sensing carriers to determine sensing information. The WTRU may determine a set of available resources of the resource allocation carrier based on the determined sensing information.

[0010] The determination of a subset of carriers for collaborative sensing may be associated with one or more of the number of carriers preconfigured with a set of collaborative sensing carriers, a set of carriers associated with the services actively performed by the WTRU, a number of indications from nearby WTRUs indicating a set of carriers available for collaborative sensing, and / or a set of carriers associated with destination ID triggering resource allocation, pre-emption, and / or resource re-evaluation.

[0011] The WTRU may perform an automatic gain control (AGC) avoidance procedure based on the determination that confirms the reserved PSCCH and / or PSSCH transmission overlaps with a reserved resource from the second WTRU.

[0012] The determination of a subset of carriers may be further based on one or more of a measured reference signal received power (RSRP) of a transmission reserving a potential PSCCH or PSSCH transmission, a priority associated with the reserved PSCCH or PSSCH resource, a priority associated with the potential PSCCH or PSSCH transmission, a relative priority between the reserved PSCCH or PSSCH resource and a reserved PSCCH or PSSCH resource of the second WTRU associated with the potentialtransmission, and / or the earlier of the reserved PSCCH or PSSCH resource or the reserved PSCCH and / or PSSCH resource of the second WTRU associated with the potential transmission.

[0013] The pre-emption checking may be based on one or more of a priority associated with the reserved PSCCH and / or PSSCH resource, a priority associated with a potential transmission, and / or a relative priority between the reserved PSCCH and / or PSSCH resource and a reserved resource of the second WTRU associated with the potential transmission.

[0014] The WTRU disable HARQ feedback if the associated PSFCH transmission overlaps with a potential transmission from the second WTRU and / or has different staring symbol than a starting or ending symbol of the potential transmission from another WTRU.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented.

[0016] FIG. 1 B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A according to an embodiment.

[0017] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1 A according to an embodiment.

[0018] FIG. 1 D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1 A according to an embodiment.

[0019] FIG. 2 is a diagram illustrating an example pre-emption resource reselection due to an automatic gain control (AGC) issue.

[0020] FIG. 3 is a diagram illustrating an example of WTRU selection of control channel 3 (CC3) to receive in a newly established unicast link to avoid an AGC reception issue.

[0021] FIG. 4 is a diagram illustrating an example receive (Rx) WTRU determination of feedback PSFCH in CC1 for physical sidelink control channel (PSCCH) and / or physical sidelink shared channel (PSSCH) transmitted in CC2 based on the required physical sidelink feedback channel (PSFCH) feedback to another PSCCH and / or PSSCH in control channel 1 (CC1) at the same PSFCH occasion.

[0022] FIG. 5 is a diagram illustrating an example WTRU determination of the number of sidelink synchronization signal block (S-SSB) repetitions based on the transmission level of S-SSB.DETAILED DESCRIPTION

[0023] FIG. 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0024] As shown in FIG. 1 A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a CN 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or a “ST A”, may be configured to transmit and / or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g, remote surgery), an industrial device and applications (e.g, a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a WTRU.

[0025] The communications systems 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interfacewith at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the I nternet 110, and / or the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0026] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0027] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0028] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed UL Packet Access (HSUPA).

[0029] I n an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0030] I n an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access, which may establish the air interface 116 using New Radio (NR).

[0031] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g, a eNB and a gNB).

[0032] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e, Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0033] The base station 114b in FIG. 1 A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g, for use by drones), a roadway, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0034] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may be utilizing a NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0035] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 may include circuit- switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0036] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0037] FIG. 1 B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1 B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0038] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. 1B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0039] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g. , the base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0040] Although the transmit / receive element 122 is depicted in FIG. 1 B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0041] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0042] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0043] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0044] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable locationdetermination method while remaining consistent with an embodiment.

[0045] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, anaccelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0046] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and / or simultaneous. The full duplex radio may include an interference management unit 139 to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).

[0047] FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0048] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0049] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, and the like. As shown in FIG. 1 C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0050] The CN 106 shown in FIG. 1 C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0051] The MME 162 may be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible forauthenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0052] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter- eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0053] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0054] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0055] Although the WTRU is described in FIGS. 1 A-1 D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0056] In representative embodiments, the other network 112 may be a WLAN.

[0057] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in to and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to thedestination STA. The traffic between ST As within a BSS may be considered and / or referred to as peer-to- peer traffic. The peer-to-peer traffic may be sent between (e.g. , directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11 e DLS or an 802.11 z tunneled DLS (TDLS). A WLAN using an Independent BSS (I BSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an “ad- hoc” mode of communication.

[0058] When using the 802.11 ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g, only one station) may transmit at any given time in a given BSS.

[0059] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0060] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0061] Sub 1 GHz modes of operation are supported by 802.11 af and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.11 af and 802.11 ah relative to those used in 802.11 n, and802.11ac. 802.11 af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11 ah may support Meter Type Control / Machine- Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0062] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11 n, 802.11 ac, 802.11 af, and 802.11 ah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a ST A, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11 ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0063] In the United States, the available frequency bands, which may be used by 802.11 ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11 ah is 6 MHz to 26 MHz depending on the country code.

[0064] FIG. 1 D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0065] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMOtechnology. For example, gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0066] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0067] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0068] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA,routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. 1D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0069] The CN 115 shown in FIG. 1 D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0070] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and / or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0071] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating WTRU IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0072] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwardingpackets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0073] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0074] In view of Figures 1A-1 D, and the corresponding description of Figures 1A-1 D, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-ab, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0075] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or may performing testing using over-the-air wireless communications.

[0076] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / orwireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0077] A wireless transmit / receive unit (WTRU) may determine a set of carriers for collaborative sensing. The WTRU may detect a potential transmission overlapping and / or having different starting or ending symbol with its reserved resource. The WTRU may perform automatic gain control (AGC)-issue avoidance procedure. The WTRU may determine whether to trigger resource allocation or puncture and / or ratematch the overlapping duration. The WTRU may exclude the resource overlapping with the reservation from other WTRU. The WTRU may perform a logical channel prioritization (LCP) procedure to determine which logical channel (LCH) to multiplex the transport block (TB). The WTRU may determine whether to enable / disable hybrid automatic repeat request (HARQ) feedback. The WTRU may be configured with a set of restrictions for carrier selection. The WTRU may select a set of carriers for the unicast link. The WTRU may indicate which carrier to feedback physical sidelink feedback channel (PSFCH) for each physical sidelink control channel (PSCCH) and / or physical sidelink shared channel (PSSCH). The WTRU may determine which carrier to feedback PSFCH for an associated PSCCH and / or PSSCH. The WTRU may request another WTRU to send sensing information for the set of carriers. The WTRU may select a carrier based on the sensing information reported from other WTRU. The WTRU may determine the priority associated with sidelink synchronization signal block (S-SSB) transmission per carrier. The WTRU may determine the potential transmission power of S-SSB in each carrier in each S-SSB occasion. The WTRU may determine whether to transmit S-SSB in each carrier in one configured S-SSB occasion. The WTRU may determine the number of S-SSB repetition per S-SSB occasion.

[0078] Long term evolution (LTE) vehicle-to-everything (V2X) may support one subcarrier spacing (SCS) of 15 KHz for all carriers. For carrier aggregation, all the aggregated carriers may have the same synchronization configuration. All the aggregated carriers may be synchronized.

[0079] Multicarrier may currently be specified for new radio (NR) sidelink (SL). Multicarrier may be expected to use LTE as a baseline, while potentially considering some differences to account for unicast transmission in NR. Many restrictions in configuration may be imposed to simplify the design. For example, the imposed restrictions in configuration may include the same configuration of SCS, physical sidelink feedback channel (PSFCH), and / or sidelink synchronization signal block (S-SSB) across all carriers.

[0080] Multicarrier operation in NR Sidelink Evolution (SLE) may need to consider different transmission duration of various transmission channels (e.g., physical sidelink control channel (PSCCH) and / or physical sidelink shared channel (PSSCH) and / or physical sidelink feedback channel (PSFCH) and / or the samechannel in different carriers with different SCSs. NR SLE may also aggregate multiple carriers with various synchronization configurations due to operation band and the desired latency of packet delivery (e.g., the network may configure a larger SCS for targeting the lower latency requirement services).

[0081] For carrier aggregation, the receive (Rx) wireless transmit / receive unit (WTRU) may perform automatic gain control (AGC) convergence over multiple carriers. While a Rx WTRU is receiving a channel (e.g., PSCCH and / or PSSCH), and another WTRU transmitting may be in the middle of its reception. In such case, the receiving channel may be affected, and / or the WTRU may fail to decode the channel. AGC issues may severely affect the reliability of the packet reception, e.g., in the system with non-synchronized and various transmission in multiple carriers.

[0082] Moreover, due to limited reception capability and / or imbalance in transmit (Tx) and / or Rx carriers, a WTRU may not be able to transmit and / or receive in the same set of carriers. Therefore, it may be desirable to support cross carrier feedback, wherein the WTRU may feedback in a different carrier compared to the associated data. Directions on how to perform carrier selection for transmission of HARQ feedback may be needed.

[0083] Moreover, due to limited sensing capability and / or imbalance in Tx and / or Rx carriers, the WTRU may not sense a carrier before carrier selection. However, the WTRU may take advantage of the surrounding WTRUs (e.g., via inter WTRU coordination (IUC)) to decide carrier reselection properly. The design to enable such a WTRU to support another WTRU in carrier selection may be considered.

[0084] Directions on how to design a synchronization procedure may be provided for multi-carrier. These directions may ensure a proper synchronization coverage of all carriers considering different SCS and / or synchronization configuration in different carriers.

[0085] The terms “resource allocation,” “pre-emption,” and “resource re-evaluation” may be used interchangeably herein. The terms “resource allocation,” “pre-emption,” and “resource re-evaluation” may describe the procedure to identify whether a preselected resource and / or a reserved resource can identify the available resources for transmission. The preselected resource and / or a reserved resource may make this identification by performing sensing and / or extracting a sensing result.

[0086] The term “WTRU” may refer to a WTRU that receives configuration from the gNB (e.g., via dedicated radio resource control (RRC) signaling and / or a system information block (SIB)) and / or the WTRU preconfigured with information (e.g., a threshold).

[0087] For carrier aggregation, the Rx WTRU may perform AGC convergence over multiple carriers. While the WTRU is receiving a channel (e.g., PSCCH and / or PSSCH), the receiving channel may be affected andmay fail to decode the channel, e.g., if another WTRU transmitting in the middle of its reception. Carrier selection and / or resource allocation for multiple carriers consider AGC problem.

[0088] A WTRU may perform pre-emption checking to determine whether its reserved PSCCH and / or PSSCH resource and / or associated PSFCH overlaps and have different starting or ending symbols with the reserved resource from other WTRU in one carrier. The WTRU may determine whether to puncture and / or ratematch the overlapping symbols of PSCCH and / or PSSCH or reselect another resource based on the overlapping duration. The WTRU may determine whether to transmit hybrid automatic repeat request (HARQ) enabled / disabled transport block (TB) based on whether the associated PSFCH occasion overlaps and has different starting or ending symbol with a reserved physical sidelink control channel (PSCCH) and / or physical sidelink shared channel (PSSCH) or the associated PSFCH of another WTRU from a carrier.

[0089] In examples, the WTRU may transmit a PSCCH and / or PSSCH and reserve one PSCCH and / or PSCCH for further transmission. Before the reserved PSCCH and / or PSSCH resource, the WTRU may perform pre-emption checking to determine whether its reserved PSCCH and / or PSSCH resource and / or associated PSFCH overlaps and / pr has different staring symbols with a reserved resource from another WTRU in another carrier. The WTRU may then determine whether to ratematch and / or puncture the overlapping symbol of the reserved PSCCH and / or PSSCH and / or reselect another resource based on the overlapping duration. The WTRU may transmit HARQ enabled or disabled TB based on whether the associated PSFCH occasion overlaps and / or has different starting or ending symbols with a reserved PSCCH and / or PSSCH or the associated PSFCH of another WTRU from another carrier.

[0090] A WTRU (e.g., Tx WTRU) may be configured with a set of carriers for AGC avoidance resource allocation, and / or an overlapping duration threshold. The WTRU may perform a PSCCH and / or PSSCH transmission. For example, the WTRU may reserve a resource for PSCCH and / or PSSCH transmission. The WTRU may perform pre-emption checking of the reserved PSCCH and / or PSSCH. The associated PSFCH occasion may overlap and / or have different starting or ending symbols with a reserved PSCCH and / or PSSCH and / or the associated PSFCH of another WTRU from a different carrier. Under these conditions, the WTRU may select HARQ disabled LCHs to multiplex the TB to transmit in the resource. The WTRU’s reserved PSCCH and / or PSSCH resource may overlap and / or have different starting or ending symbols with the reserved resource from other WTRU in another carrier. Under these conditions, if the overlap duration exceeds a threshold, then the WTRU may reselect another resource. Otherwise, theWTRU may puncture and / or ratematch the overlapping duration. The WTRU may perform PSCCH and / or PSSCH transmission in the selected resource.

[0091] The WTRU may determine the set of carriers for collaborative sensing based on one or more of the following: a WTRU may perform resource allocation, pre-emption, and / or resource re-evaluation in one carrier. Herein, the carrier on which the WTRU performs resource allocation, pre-emption, and / or resource re-evaluation may be referred to as the “resource allocation carrier.” The WTRU may then determine the set of carriers for collaborative sensing; these carriers may be referred to as the “set of collaborative sensing carriers” of the resource allocation carrier. Specifically, the WTRU may perform sensing in the set of collaborative sensing carriers in a sensing window to perform resource selection, pre-emption, and / or resource re-evaluation in the resource allocation carrier. The WTRU may determine the set of available resources in the resource allocation window of the resource allocation carrier based on the sensing information detected in the set of collaborative sensing carriers.

[0092] A configured and / or preconfigured set of carriers may determine the set of collaborative sensing carriers of the resource allocation carrier. For example, for each resource allocation carrier, the WTRU may be configured with a set of collaborative sensing carriers for sensing.

[0093] The set of carriers associated with the current active services in the resource allocation carrier (e.g., the set of active destination IDs the WTRU is running) may determine the set of collaborative sensing carriers of the resource allocation carrier. For example, the WTRU may be configured with a set of carriers for each service (e.g., destination ID). The WTRU may then determine the set of services for use by the current resource allocation carrier. The WTRU may then determine the set of collaborative carriers of the current resource allocation carrier based on the set of services (e.g., destination ID) using the current resource allocation carrier.

[0094] The set of carriers the WTRU is aggregating may determine the set of collaborative sensing carriers of the resource allocation carrier. For example, the WTRU may determine the set of collaborative carriers of the current carrier as a set or a subset of carriers the WTRU is aggregating.

[0095] An indication from another WTRU (e.g., peer WTRU) may determine the set of collaborative sensing carriers of the resource allocation. For example, the WTRU may have established a connection with a peer WTRU. The WTRU may then receive an indication from the peer WTRU associated with a set of carriers for collaborative sensing if the WTRU performs resource allocation, pre-emption, and / or re- evaluation in one of the carriers in the set. The WTRU may then perform collaborative sensing in theindicated set of carriers if the WTRU performs resource allocation in one of the carriers in the indicated set of carriers.

[0096] The of carriers associated with the destination ID triggering resource allocation, pre-emption and / or resource re-evaluation may determine the set of collaborative sensing carriers of the resource allocation carrier. For example, the WTRU may trigger resource allocation, pre-emption, and / or re-evaluation for potential transmission of a TB associated with one destination ID. The WTRU may then determine the set of carriers associated with the destination ID. The WTRU may then consider the set of carriers associated with the destination ID as the set of collaborative sensing carriers for the resource allocation carrier.

[0097] The WTRU may detect a potential transmission overlapping and / or having different starting or ending symbol with its reserved resource. In examples, the WTRU may detect a reservation / indication for a potential transmission (e.g., PSCCH and / or PSSCH, and / or PSFCH) in one resource of one of the collaborative sensing carriers. This resource may overlap and / or have different starting or ending symbols in time domain with its reserved resource. The WTRU may detect the potential transmission on a carrier of the set of collaborative sensing carriers based on decoding SCI from another WTRU. This other WTRU may reserve and / or indicate the potential transmission. In one example, the WTRU may determine that the potential transmission affects its transmission. Under these circumstances, the Rx WTRU may fail to decode its transmission due to AGC problem. In another examples, the transmission of the WTRU in the reserved resource may affect the detected potential transmission. Under these circumstances, the Rx WTRU of the detected potential transmission may fail to decode the transmission due to AGC problem. The WTRU may then determine whether to trigger AGC-issue avoidance procedure.

[0098] The WTRU may trigger the AGC-issue avoidance procedure based on the measured RSRP of the transmission reserving the potential transmission. For example, the WTRU may trigger AGC-issue avoidance procedure if the measured RSRP of the reserving transmission exceeds a configured threshold. Otherwise, the WTRU may not trigger the AGC-issue avoidance procedure. Specifically, the WTRU may continue transmitting in the reserved resource.

[0099] The WTRU may trigger the AGC-issue avoidance procedure based on the priority associated with its reserved resource. In examples, the WTRU may trigger AGC-issue avoidance procedure if the priority associated with the WTRU’s reserved resource is smaller than a configured threshold. Otherwise, the WTRU may not trigger the procedure. This approach may protect the potential transmission of the other WTRU. In another example, the WTRU may trigger AGC-issue avoidance procedure if the priorityassociated with the WTRU’s reserved resource is larger than a configured threshold. Otherwise, the WTRU may not trigger the procedure. This approach may protect the WTRU’s own transmission.

[0100] The WTRU may trigger the AGC-issue avoidance procedure based on the priority associated with the detected potential transmission. For example, the WTRU may trigger AGC-issue avoidance procedure if the priority associated with the reservation of the other WTRU is larger than a configured threshold. Otherwise, the WTRU may not trigger the procedure.

[0101] The WTRU may trigger the AGC-issue avoidance procedure based on the relative priority between the reserved resource of the WTRU and / or the reserved resource of the other WTRU. For example, the WTRU may trigger AGC-issue avoidance procedure if the priority associated with the reservation of the other WTRU is larger than the priority associated with the WTRU’s reserved resource. Otherwise, the WTRU may not trigger the procedure.

[0102] The WTRU may determine whether to trigger AGC-issue avoidance procedure based on whether the reserved resource from the WTRU is earlier than the reserved source from the other WTRU. For example, the WTRU may trigger the AGC-issue avoidance procedure if the WTRU’s reservation resource is earlier than the other WTRU’s reservation resource.

[0103] The WTRU may perform AGC-issue avoidance procedure to solve the potential AGC issue between two resources. To perform the AGC-issue avoidance procedure, the WTRU may trigger resource reselection. For example, the WTRU may trigger resource reselection to reselect another resource if the priority associated with the WTRU’s reserved resource is smaller than a configured threshold. The WTRU may trigger resource reselection if the priority associated with the WTRU’s reserved resource is smaller than the priority associated with the other WTRU’s reserved resource.

[0104] To perform the AGC-issue avoidance procedure, the WTRU may send IUC information to the WTRU reserving the potential transmission. For example, the WTRU may trigger sending IUC information to the other WTRU (e.g., conflict indication) to in turn trigger the other WTRU to reselect another resource. This may also trigger the other WTRU to stop using the reserved resource if the priority associated with the other WTRU’s reserved resource is smaller than a configured threshold. The WTRU may send IUC information to the other WTRU (e.g., conflict indication) if the priority associated with the WTRU’s reserved resource is larger than the priority associated with the other WTRU’s reserved resource.

[0105] The WTRU may puncture and / or ratematch the overlapping duration. For example, the WTRU may puncture and / or ratematch the overlapping duration if the overlapping duration is smaller than a configured threshold. Otherwise, the WTRU may reselect another resource. The WTRU may then indicate (e.g., in theSCI) that the WTRU has puncture and / or ratematch an overlapping duration to support the other WTRU in decoding the TB.

[0106] To perform the AGC-issue avoidance procedure, the WTRU may transmit in the overlapping duration by using dummy data and / or repeat one or more symbols in the non-overlapping duration. The WTRU may indicate such transmission in the SCI to support a Rx WTRU in decoding the transmission.

[0107] To perform the AGC-issue avoidance procedure, the WTRU may adjust the transmission power in the reserved resource. For example, the WTRU may reduce its transmission power to reduce the AGC issue.

[0108] To perform the AGC-issue avoidance procedure, the WTRU may drop the reserved resource. For example, the WTRU may determine to drop the reserved resource if the time gap between the resource reservation detection and the WTRU’s reserved resource is smaller than a configured threshold. Otherwise, the WTRU may reselect another resource.

[0109] The WTRU may determine whether to trigger resource allocation or puncture and / or ratematch the overlapping duration. In examples, the WTRU may be configured with two possible procedures to avoid the AGC problem: the WTRU may either perform resource reselection or puncture and / or ratematch the overlapping duration.

[0110] The WTRU may determine which procedure to perform based on the overlapping duration. For example, the WTRU may puncture and / or ratematch the overlapping duration if the overlapping duration is smaller than a configured threshold. Otherwise, the WTRU may reselect another resource.

[0111] The WTRU may determine which procedure to perform based on the priority associated with the reserved resource of the WTRU. For example, the WTRU may puncture and / or ratematch the overlapping duration if the overlapping duration is smaller than a configured threshold. Otherwise, the WTRU may reselect another resource.

[0112] The WTRU may determine which procedure to perform based on the priority associated with the reserved resource of the other WTRU. For example, the WTRU may puncture and / or ratematch the overlapping duration if the overlapping duration is smaller than a configured threshold. Otherwise, the WTRU may reselect another resource.

[0113] The WTRU may determine which procedure to perform based on the relative priority between the reserved resource of the WTRU and / or the reserved resource of the other WTRU. For example, the WTRU may puncture and / or ratematch the overlapping duration if the overlapping duration is smaller than a configured threshold. Otherwise, the WTRU may reselect another resource.

[0114] The WTRU may exclude the resource(s) overlapping with the reservation from another WTRU. In examples, the WTRU may perform resource allocation in the resource allocation carrier. The WTRU may exclude the resources in the slot overlapping and / or having different starting or ending symbols with the reserved resource from other WTRU in the set of collaborative sensing carriers. This approach may reduce the AGC issue during the resource allocation procedure.

[0115] The WTRU may perform a procedure to determine which LCH to multiplex the TB. In examples, the WTRU may perform LCP procedure to multiplex in a TB to transmit in a reserved resource. If the associated PSFCH transmission overlaps and has different starting or ending symbols with a potential transmission from another WTRU, the WTRU may perform an adjusted LCP procedure. In this adjusted LCP procedure, the WTRU may select a LCH with HARQ disabled to be multiplexed in the TB.

[0116] The WTRU may determine whether to enable or disable HARQ feedback. In examples, if the associated PSFCH transmission overlaps and has different staring symbols with a potential transmission from another WTRU, the WTRU may disable HARQ feedback. The WTRU may set the HARQ feedback bitfield in a sidelink control information (SCI) to be disabled, which may explicitly indicate that the WTRU does not require the Rx WTRU to feedback HARQ status associated with the transmission. In another example, the WTRU may indicate the Rx WTRU to feedback PSFCH on another occasion.

[0117] FIG. 2 depicts an example pre-emption resource reselection 200 due to AGC issue. As shown in FIG. 2, the WTRU may perform pre-emption in resource allocation CC1 202a. The WTRU may be configured with a set of collaborative sensing carriers CC1 , CC2, and CC3 202a-c to perform sensing. The WTRU may perform sensing in the sensing window 204. The WTRU may detect another WTRU reserving a transmission in CC2 202b overlapping and / or having different starting or ending symbols with its reserved resource. The WTRU may transmit in the reserved resource. The WTRU may detect its associated PSFCH 206 overlaps and / or has different staring symbol with a reserved resource in CC3 202c. The WTRU may perform LCP procedure to multiplex LCHs with HARQ disabled in the TB transmitting in the reserved resource.

[0118] A WTRU may determine the set of carriers to receive and / or transmit for a unicast link based on the SCS and / or the PSFCH configuration associated with the carrier. The WTRU may indicate the determined set of carriers to the peer WTRU.

[0119] The WTRU (e.g., Rx WTRU) may be configured to perform the following. The WTRU may be configured with a restriction to select a carrier for carrier aggregation (CA). The restriction to select a carrier for CA may include one or more of a maximum number of carriers (e.g., a number N) for CA, frequencyband, SCS and / or PSFCH configuration, and / or configured resource selection type (e.g., full sensing, partial sensing, random). The WTRU may have established and / or selected a set of carriers for sidelink CA. The WTRU may receive a PC5 establishment message from a peer WTRU to establish a unicast link. This PC5 establishment message may indicate the set of potential carriers and / or associated configurations for the unicast link.

[0120] The WTRU may determine the set of carriers to receive and / or transmit for the unicast link based on the configured carrier selection restriction and / or prioritization. For example, the WTRU may first restrict the carrier in the same band with one of the established and / or selected carriers. Then the WTRU may restrict the carrier with the same SCS and / or PSFCH configuration with one of the established and / or selected carriers. Then the WTRU may restrict the full sensing carrier RA until the maximum number of carriers (e.g., a number N) for CA is reached. The WTRU may send the set of carriers for the unicast communication to the peer WTRU if the set has at least one carrier. Otherwise, the WTRU may reject the link connection with the peer WTRU.

[0121] The WTRU may be configured with a set of restrictions for carrier selection. In examples, the WTRU may be configured with one or any combination of the following restrictions to select one or more carriers for carrier aggregation: for example, he WTRU may be configured with the maximum number of carriers (e.g., a number N) for carrier aggregation.

[0122] The WTRU may be configured with the frequency band. For example, the WTRU may select an additional carrier in the same frequency band with one carrier in the set of already established / selected carriers.

[0123] The WTRU may be configured with SCS and / or PSFCH configuration, to select an additional carrier having the same SCS as one of the established and / or selected carriers. The WTRU may select an additional carrier having the same SCS and / or PSFCH configuration (e.g., the offset and periodicity of PSFCH occasion) with one of the already established and / or selected carriers. This approach may assist the WTRU in avoiding the AGC issue in the set of receiver carriers.

[0124] The WTRU may be configured with configured resource selection types (e.g., full sensing, partial sensing, and / or random) in the carrier for carrier prioritization. For example, the WTRU may be restricted to select carriers having a resource pool configured with full sensing. The WTRU may select carriers having a resource pool configured with full sensing and / or partial sensing. The WTRU be restricted to select a carrier having a resource pool configured with random resource allocation.

[0125] The WTRU may be configured with a prioritization order for carrier selection. In examples, the WTRU may be configured with one or more prioritizations to select another carrier for carrier aggregation. For example, the prioritization to select another carrier for carrier aggregation may include the frequency band of the already established and / or selected carrier, SCS and / or PSFCH configuration, the adjacent carrier with the already established and / or selected carrier, and / or configured resource selection type (e.g., full sensing, partial sensing, and / or random) in the carrier for carrier prioritization.

[0126] In examples, if the number of indicated carriers exceeds the maximum number of carriers for carrier aggregation, the WTRU may first prioritize the carrier in the same frequency band with one or more of the established carriers. The WTRU may further prioritize the carriers having the same SCS and / or PSFCH configuration with one or more of the established and / or selected carriers. If the number of remaining carriers is still greater than the maximum number of carriers for carrier aggregation, the WTRU may prioritize the carrier adjacent to one or more of the already established and / or selected carriers. The WTRU may prioritize the carrier configured with full sensing following by prioritizing the carrier configured with partial sensing.

[0127] The WTRU may establish a set of carriers for CA. In examples, the WTRU may sequentially establish one or more carriers to initialize one or more services. Specifically, the WTRU may first establish one or more carriers for broadcast services. Therein, the set of carriers used for the broadcast service may initiate one or more unicast and / or group cast service.

[0128] The WTRU may receive a request connection establishment from the peer WTRU. In examples, the WTRU may receive a request for unicast connection establishment. The request may indicate the set of potential carriers and associated configuration (e.g., SCS, PSFCH configuration, and / or resource selection type) for the unicast communication.

[0129] The WTRU may select a set of carriers for the unicast link. The WTRU may then select the set of carriers from the set of indicated carriers for unicast communication. The WTRU may then send the set of selected carriers to the connection requesting WTRU if the connection requesting WTRU has at least one carrier in the set of selected carriers. The WTRU may then select the set of carriers from the set of indicated carriers based on the set of established and / or selected carriers. Specifically, the WTRU may prioritize the already established and / or selected carrier in the set of indicated carriers. In case there is no established and / or selected carrier in the set of indicated carriers, the WTRU may select additional carriers to establish for unicast communication.

[0130] In examples, the WTRU may select the set of additional carriers for unicast communication based on the configured carrier selection restriction and / or prioritization. For example, the WTRU may first restrict the carrier in the same band with one of the established / selected carriers. The WTRU may then restrict the carriers with the same SCS and / or PSFCH configuration with one of the established and / or selected carriers. The WTRU may then restrict the full sensing carrier RA until the maximum number of carriers (e.g., a number N) for CA is reached. This approach may assist the WTRU avoid the AGC issue if the WTRU selects multiple carriers with different SCS and / or PSFCH configurations.

[0131] In examples, the WTRU may not have a carrier for unicast communication. Under such circumstances, the WTRU may perform one or any combination of the following procedures. For example, he WTRU may send a unicast link connection reject to the peer WTRU. The peer WTRU may stop the connection establishment procedure between two WTRUs.

[0132] The WTRU may release one or more of the established and / or selected carriers. For example, the WTRU may release one or more of the established and / or selected carriers to select another carrier for the new unicast link. For example, the WTRU may have established and / or selected multiple carriers for one unicast link. In one approach the WTRU may release a subset of carriers in the set of established and / or selected carriers for the unicast link. The WTRU may send a message to the peer WTRU (e.g., PC5 RRC unicast re-establishment message). In the message, the WTRU may indicate the set of released carriers. Alternatively, the WTRU may indicate the new set of carriers for the unicast link communication. In another example, the WTRU may release the established unicast link.

[0133] The WTRU may reselect one or more carriers in the set of established / selected carriers. For example, the WTRU may select one or more carriers from the set of indicated carrier to replace one or more carriers in the set of established and / or selected carriers. The WTRU may indicate the new set of carriers to the peer WTRU in the already established unicast link for future unicast communication. The WTRU may send the indication using PC5 radio resource control (RRC) unicast message.

[0134] FIG. 3 depicts an example WTRU selection 300 to receive and / or transmit in a newly established unicast link to avoid AGC reception issue. As shown in FIG. 3, the WTRU may be indicated from the peer WTRU with four potential carriers for unicast communication with the peer WTRU, featured as CC2, CC3, CC4, and CC5 302b-e. CC2 and CC3 302b-c may be in one frequency band, e.g., Bandl 304a. CC4 and CC5 302d-e may be in another frequency band, e.g., Band2 304b. The WTRU may have CC1 302a as the already established carrier in Bandl 304a. The WTRU may apply the first restriction to select the component carrier in the same band with the already established component carrier. Therefore, the WTRUmay select potential CC2 and / or CC3 302b-c for potential unicast communication. Finally, the WTRU may apply the SCS and / or PSFCH configuration restriction to select the component carrier having the same configuration with the already established CC1 302a and select CC3 302c as a potential component carrier for unicast communication. The WTRU may then indicate the selected CC3 302c to the peer WTRU to begin the unicast communication.

[0135] Due to limited transmission capability, a WTRU may not be able to transmit in all the Rx carriers. Therefore, it may be beneficial to configure cross-carrier feedback. In cross-carrier feedback, the WTRU may feedback PSFCH in different carrier compared to PSCCH and / or PSSCH. Assuming that a Rx WTRU may have multiple carriers to feedback PSFCH, the WTRU may select the carrier to feedback PSFCH as described herein.

[0136] A WTRU (e.g, Rx WTRU) may determine which carrier to transmit PSFCH based on a configured or preconfigured criteria (e.g., the carrier of PSFCH associated with another PSCCH and / or PSSCH with higher priority).

[0137] The WTRU (e.g., source WTRU) may be configured with a mapping of one PSCCH and / or PSSCH resource to multiple PSFCH resources in multiple carriers. The WTRU may receive one HARQ enabled PSCCH and / or / PSSCH in one carrier. The WTRU may determine which carrier to feedback PSFCH based on one or more of the carriers having the earliest PSFCH occasion, carrier of a PSFCH associated with another PSCCH and / or PSSCH, channel busy ratio (CBR) of the resource pool, transmission power of PSFCH in the carrier, carrier having reserved PSCCH and / or PSSCH resource, and / or carrier of the dropped PSFCH (e.g., if the WTRU select a carrier for a second PSFCH). The WTRU may transmit PSFCH feedback in an associated PSFCH resource of the selected carrier.

[0138] The WTRU may request PSFCH configuration in one carrier for PSCCH and / or PSSCH in another carrier. In examples, a WTRU (e.g, Rx WTRU) may determine to perform multicarrier transmission and / or reception. The WTRU may be configured (e.g, pre-configured) with one-to-one mapping between PSCCH and / or PSSCH and / or associated PSFCH in the same resource pool. In examples, the WTRU may then request the network to configure one-to-one mapping between PSCCH and / or PSSCH and / o PSFCH in a different carrier. Under these conditions, the WTRU may transmit PSCCH and / or PSSCH in one carrier and / or feedback the associated PSFCH in another carrier. The WTRU may indicate the preferred carrier for PSCCH and / or PSSCH and / or the carrier for the associated PSFCH.

[0139] The WTRU may request the network to configure one-to-many mapping between PSCCH and / or PSSCH and the associated PSFCH. Under these conditions, the WTRU may have multiple associatedPSFCH resources in different carriers. The WTRLI may indicate the preferred carrier for PSCCH and / or PSSCH and / or the preferred carrier(s) for the associated PSFCH. The WTRU may send the request using an RRC message (e.g., sidelink WTRU information (SUI) and / or WTRU assistant information (UAI)).

[0140] The WTRU may request the additional PSFCH configuration based on one or any combination of the following:The WTRU may indicate which carrier to feedback PSFCH. In examples, the WTRU may establish a unicast link with a peer WTRU. One or both WTRUs of the unicast link may indicate which carrier to feedback the PSFCH. The indication may be transmitted using PC5 RRC message. In examples, the Tx WTRU may indicate its preferred carrier to receive PSFCH feedback of the associated PSCCH and / or PSSCH. In another example, the Rx WTRU may indicate its preferred carrier to transmit PSFCH.

[0141] The WTRU may indicate which carrier to feedback PSFCH for each PSCCH and / or PSSCH. In examples, a WTRU (e.g., Tx WTRU) may indicate which carrier to feedback PSFCH for each PSCCH and / or PSSCH. For example, the WTRU may indicate in the SCI which PSFCH resource and / or carrier to feedback PSFCH the associated PSCCH and / or PSSCH. The WTRU may be configured with two carriers to feedback PSFCH. The WTRU may be configured with a bitfield. In the bitfield, one codepoint may be associated with the first carrier (e.g., the same carrier as the PSCCH and / or PSSCH) and another codepoint may be associated with the second carrier. The size of bitfield may depend on the number of PSFCH resources and / or carriers associated with the PSCCH and / or PSSCH.

[0142] The WTRU may determine which carrier to receive PSFCH feedback based on one or any combination of the following, including whether the WTRU is required to transmit PSFCH on one occasion. For example, the WTRU (e.g., Tx WTRU) may be one of the receivers from other WTRU requiring the WTRU to feedback in one of the PSFCH occasions. The WTRU may then indicate the Rx to feedback PSFCH on another occasion.

[0143] The WTRU may determine which carrier to feedback PSFCH for an associated PSCCH and / or PSSCH. In examples, the WTRU may be configured with a mapping of one PSCCH and / or PSSCH resource to multiple PSFCH resources in multiple carriers. The WTRU may receive one HARQ enabled PSCCH and / or PSSCH in one carrier. The WTRU may then determine which PSFCH resource and / or which carrier to feedback PSFCH to the associated PSCCH and / or PSSCH.

[0144] The WTRU may determine to feedback PSFCH based on the priority associated with the PSFCH resource and / or carrier to transmit PSFCH. For example, the WTRU may be configured with multiple carriers to transmit PSFCH for PSCCH and / or PSSCH transmitted in one carrier. Therein, each PSFCH ineach carrier may be associated with one configured priority. The WTRU may then determine which PSFCH in which carrier to transmit based on the priority associated with each PSFCH in each carrier. For example, the WTRU may first select the PSFCH resource having the highest priority to transmit HARQ feedback. If the WTRU is not able to transmit PSFCH associated with the first priority (e.g., the highest priority), the WTRU may then select the PSFCH resource associated with the second priority (e.g., the second highest priority).

[0145] The WTRU may determine one or more (e.g., all) associated PSFCH resources based on the feedback PSFCH in one or more (e.g., all) associated PSFCH resources. The WTRU may feedback PSFCH in the earliest PSFCH occasion. If the WTRU fails to transmit PSFCH on one occasion (e.g., due to the PSFCH prioritization procedure), the WTRU may transmit PSFCH in the subsequent occasion.

[0146] The WTRU may determine indication from the Tx WTRU. For example, the WTRU may receive an indication from the Tx WTRU (e.g., in SCI) which carrier to feedback PSFCH. The WTRU may then feedback PSFCH in the indicated carrier.

[0147] The WTRU may determine the carrier of the associated PSCCH and / or PSSCH. For example, the WTRU may prioritize transmitting PSFCH in the carrier of the associated PSCCH and / or PSSCH. The WTRU may transmit PSFCH in another carrier if the carrier associated with the PSCCH and / or PSSCH is deprioritized (e.g., due to the PSFCH prioritization procedure).

[0148] The WTRU may determine the periodicity of PSFCH. For example, the WTRU may prioritize selecting the carrier having PSFCH with smallest PSFCH periodicity to transmit PSFCH.

[0149] The WTRU may then determine the SCS of the carrier. In examples, the WTRU may prioritize selecting the carrier having PSFCH with the highest SCS. In another example, the WTRU may prioritize selecting the carrier having PSFCH with the lowest SCS.

[0150] The WTRU may determine the timing of each associated PSFCH. For example, the WTRU may feedback PSFCH in the carrier with the earlier PSFCH occasion.

[0151] The WTRU may determine the required number of carrier, PSFCH resources, and / or transmission occasions to transmit PSFCH. In examples, the WTRU may prioritize transmitting PSFCH in the resource requiring the WTRU to transmit in the lowest number of carriers. For example, the WTRU may first prioritize the PSFCH occasion requiring the WTRU to transmit in one carrier. The WTRU may then prioritize the PSFCH occasion requiring the WTRU to transmit in two carriers, and so on. For PSFCH transmission in multiple carriers, the WTRU may prioritize the PSFCH occasion requiring the WTRU to transmit in consecutive carriers.,

[0152] The WTRU may prioritize transmitting PSFCH in the occasion requiring the WTRU to transmit the smallest number of PSFCHs. For example, the WTRU may first prioritize the PSFCH occasion requiring the WTRU to transmit one PSFCH. The WTRU may then prioritize the PSFCH occasion requiring the WTRU to transmit two PSFCHs, and so on. The WTRU may transmit feedback for multiple PSCCH and / or PSSCH. The WTRU may select the PSFCH resource requiring the WTRU to transmit in the smallest number of occasions.

[0153] The WTRU may determine whether to transmit PSFCH for another PSCCH and / or PSSCH in the same occasion with one or more PSCH resources of the associated PSCCH and / or PSSCH. For example, the WTRU may transmit PSFCH for another PSCCH and / or PSSCH in one carrier. The WTRU may then prioritize to transmit PSFCH for the current PSCCH and / or PSSCH in the PSFCH resource of the same carrier with the other PSFCH.

[0154] The WTRU may determine CBR of the resource pool. For example, the WTRU may feedback PSFCH in the carrier having the associated resource pool with the lowest CBR.

[0155] The WTRU may determine transmission power of PSFCH in the carrier. The WTRU may be configured with open loop power control (OLPC) parameters for PSFCH in one resource pool of each carrier. In examples, the WTRU may transmit PSFCH in the carrier with highest transmission power. The WTRU may transmit PSFCH in the carrier without DL pathloss being configured for OLPC. This approach may increase the reliability of PSFCH transmission. In another example, the WTRU may transmit PSFCH in the carrier with the lowest required transmission power.

[0156] The WTRU may prioritize which PSFCH to transmit and / or receive. In examples, the WTRU may have multiple PSFCHs to transmit in one occasion in multiple carriers. The WTRU may have limited PSFCH transmission capability. For example, the WTRU may transmit PSFCH in one carrier (e.g., one carrier only). The WTRU may then prioritize to transmit PSFCH in the carrier with the highest associated priority of the PSFCH. The priority of the PSFCH may be based on the priority of the associated PSCCH and / or PSSCH. The WTRU may then include other PSFCH resources in the determined carriers. The order of the selected PSFH resource may be based on the priority of the associated PSCCH and / or PSSCH.

[0157] FIG. 4 depicts an example Rx WTRU determination 400 to feedback PSFCH in CC1 402a for PSCCH and / or PSSCH transmitted in CC2 402b, for example, based on the required PSFCH feedback to another PSCCH and / or PSSCH in CC1 402a at the same PSFCH occasion. As shown in FIG. 4, each PSCCH and / or PSSCH transmission in CC2 402b may have two associated PSFCH resources in CC1 and CC2 402a-b to feedback PSFCH. In the same PSFCH occasion, the WTRU may feedback PSFCH foranother PSCCH and / or PSSCH in CC1 402a. The WTRU may then determine to feedback PSFCH in CC1 402a for PSCCH and / or PSSCH transmitted in CC2 402b. The WTRU may then feedback two PSFCHs in the same CC1 402a for two PSCCH and / or PSSCH in CC1 and CC2 402a-b.

[0158] The Rx WTRU may have limited Rx capability. The Rx WTRU may not be able to measure one or more (e.g., all) carriers. IUC may assist one WTRU aware of a non-monitored carrier by requesting another WTRU to report the channel condition in the carrier. The WTRU may use IUC for carrier selection and / or reselection as described herein.

[0159] A WTRU (e.g., Tx WTRU) may request another WTRU (e.g., peer WTRU) to transmit IUC for carrier reselection. Upon reception of IUC from the peer WTRU, the WTRU may determine which carrier to select based on one of the parameters (e.g., RSRP threshold to obtain X% resources) indicated in the IUC message. The WTRU may transmit an indicated resource in the selected carrier.

[0160] A WTRU (e.g., Tx WTRU) may perform transmission in one carrier. The WTRU may trigger carrier reselection. The WTRU may send a request for another WTRU (e.g., peer WTRU in unicast) to report IUC for carrier reselection. The request may include one or more of indication of IUC type (e.g., for carrier reselection), the set of potential carriers, and / or the carrier evaluation parameters (e.g., percentage of available resources, RSRP threshold to have X% of resources, CBR). The WTRU may receive IUC message from the peer WTRU. The IUC message may include one or more of the percentage and / or number of the available resources in each indicated carrier, the RSRP threshold to have X% resource, CBR of one resource pool in each carrier, and / or a set of preferred resources in each carrier.

[0161] The WTRU may select a carrier based on one of the carrier evaluation parameters IUC report from the peer WTRU. For example, the WTRU may select the carrier with the lowest CBR reported from the peer WTRU. Alternatively, the WTRU may select the carrier with the highest percentage / number of available resources reported from the peer WTRU. The WTRU may select the carrier with the lowest RSRP threshold to have X% of resource. Moreover, the WTRU may select and transmit data on one of the indicated resources in the selected carrier.

[0162] The WTRU may request another WTRU to send sensing information for the set of carriers. In examples, a WTRU may perform transmission in one carrier. The WTRU may then trigger carrier reselection to select another carrier. The WTRU may then request another WTRU to indicate sensing information in the set of potential carriers for carrier selection. Specifically, the WTRU may request another WTRU to transmit an IUC message. SCI, media access control element (MAC CE), and / or PC5 RRC maytransmit the IUC message. The IUC request message may include one or more of IUC request type, the set of potential carriers for carrier reselection, and / or one or more evaluated parameters for carrier resection.

[0163] The WTRU may indicate the IUC request type in the IUC request message. A WTRU may be configured with multiple IUC request types. The WTRU may then indicate which IUC request type it is transmitting. The one or more IUC request types may include IUC request for carrier reselection, and / or IUC request for resource allocation.

[0164] The WTRU may indicate set of evaluated parameters for carrier reselection. The WTRU may be configured with one or more carrier evaluated parameters for carrier resection. The WTRU may then indicate which parameter(s) to request the peer WTRU to report. For example, the WTRU may be configured with one or more evaluated parameters. The one or more evaluated parameters may include the CBR of the resource pool associated with the carrier, the percentage and / or number of available resources in a resource selection window, RSRP threshold to have X% available resources in a resource selection window, and / or the channel condition between the WTRU and the peer WTRU in each carrier. This channel condition may include the CBR associated with each carrier, sidelink measurement in one or more transmissions between the WTRU and the peer WTRU in the carrier such as sidelink-reference signal received power (SL-RSRP), sidelink pathloss (SL-PL), and / or sidelink- received signal strength indicator (SL-RSSI).

[0165] The WTRU may indicate the set of carrier(s) to request the sensing information. The WTRU may determine which carrier(s) to request the sensing information. The WTRU may determine which carrier(s) to request the sensing information based on one or more of the set of carriers configured for a service (e.g., destination ID) which triggers carrier reselection, and / or the set of already established / selected carriers. For example, the WTRU may indicate the carriers to the peer WTRU such that it can aggregate one or more indicated carriers with the already established and / or selected carriers.

[0166] The WTRU may determine the parameters used to support the peer WTRU in the peer WTRU’s carrier selection. The WTRU may be configured with one or more parameters to indicate to the peer WTRU in determining the carrier evaluated parameters. The WTRU may then indicate one or more parameters which may include the RSRP threshold to determine the availability of a resource, the resource selection window and / or duration (e.g., the resource selection window and / or duration which may include the starting slot, the ending slot, and / or the duration of the window), the sensing window and / or duration, the priority associated with the resource selection (used to replace the priority of the TB during the resource allocation procedure), the received signal strength indicator (RSSI) threshold to determine the availability of aresource for CBR measurement, and / or the channel condition between the WTRU and the peer WTRU in each carrier.

[0167] The WTRU may transmit the IUC message to the IUC request WTRU. In examples, the peer WTRU may perform resource selection using one or more parameters indicated by the IUC request WTRU to determine the carrier evaluated parameters and / or potentially a set of preferred resources. The WTRU may then transmit the IUC to the requested WTRU.

[0168] The WTRU may select a carrier based on the sensing information reported from the other WTRU. The WTRU may determine which set of carriers to select based on the sensing information indicated from the peer WTRU. In examples, the WTRU may receive CBR information from the peer WTRU; the WTRU may select the carrier with the lowest CBR. Alternatively, the WTRU may select a certain configured number of carriers in the ascending order of CBR value; the WTRU may select one or more (e.g., all) carriers having CBR being smaller than a configured threshold. The WTRU may receive the percentage and / or number of available resources from the peer WTRU. The WTRU may select the carrier with the highest value of the percentage and / or number of available resources, or the WTRU may select a certain configured number of carriers in the ascending order of the percentage and / or number of available resources. In another approach, the WTRU may select one or more (e.g., all) carriers having the percentage and / or number of available resources being greater than a configured threshold. The WTRU may receive RSRP threshold reported from the peer WTRU. The WTRU may select the carrier with the lowest RSRP threshold and / or select a certain configured number of carriers in the ascending order of RSRP threshold value. The WTRU may select one or more (e.g., all) carriers having RSRP threshold being smaller than a configured threshold. The WTRU may not reselect another carrier if the value of one or more (e.g., all) reported carrier evaluated parameters does not meet a configured threshold. AA The WTRU may reselect the carrier having the highest or lowest channel condition parameters such as SL- RSRP, SL-PL, and / or SL-RSSI. The peer WTRU may indicate these parameters in a IUC message.

[0169] The WTRU may perform transmission in the indicated resource in the selected carriers. Upon reselecting one of the carriers selected indicated by the peer WTRU, the WTRU may transmit in the carrier using one or more of the indicated resources by the peer WTRU. The WTRU may restrict to use the resources for data transmission to the peer WTRU (e.g., the peer WTRU only).

[0170] When the WTRU is required to transmit S-SSB in multiple carriers, power sharing may affect the coverage of S-SSB in each carrier. Designing the S-SSB transmission procedure to maintain the coverage of S-SSB in each carrier is described herein.

[0171] A WTRU may determine whether to transmit a S-SSB on one occasion of a carrier based on the set of carriers having S-SSB resource in the occasion and / or the associated S-SSB priority. The WTRU may then determine the number of repetitions to transmit S-SSB on one occasion based on the determined transmission power and the configured number of S-SSB repetitions per power level.

[0172] A WTRU may be configured with the set of carriers for S-SSB transmission carrier aggregations. The WTRU may be configured with coverage requirements of S-SSB per carrier (e.g., the number of S- SSB repetitions per transmission power level). The WTRU may be configured with the minimum transmission power for S-SSB per carrier. The WTRU may determine the priority of S-SSB based on the SCS associated with the carrier.

[0173] For each synchronization occasions, the WTRU may determine which set of carriers to transmit based on the minimum transmission power of S-SSB in each carrier and the priority of S-SSB in each carrier. For example, the WTRU may sequentially allocate power for S-SSB in the descending order of priority. The WTRU may determine the number of S-SSB repetitions in each carrier based on the determined transmission power and / or the minimum required transmission power. For example, if the transmission power is smaller than a first threshold, the WTRU may transmit two S-SSBs. If the transmission power is smaller than a second threshold, the WTRU may transmit 4 S-SSBs. The WTRU may perform synchronization transmission in the set of determined S-SSB resources in the set of selected carriers for synchronization transmission.

[0174] The WTRU may be configured with S-SSB transmission in multiple carriers. The parameters for S- SSB transmission in one or multiple carriers may include the set of carriers for S-SSB transmission carrier aggregations. For example, the WTRU may transmit S-SSB in the set of configured carriers for S-SSB transmission.

[0175] The parameters for S-SSB transmission in one or multiple carriers may include the minimum number of S-SSB occasions transmission per synchronization period. For example, the WTRU may transmit in a minimum number of S-SSB occasions per synchronization period. This approach may guarantee the availability of synchronization transmission per synchronization period.

[0176] The parameters for S-SSB transmission in one or multiple carriers may include the maximum number of S-SSB occasions transmission per S-SSB period. This approach may minimize power consumption of the WTRU in synchronization transmission.

[0177] The parameters for S-SSB transmission in one or multiple carriers may include the set of S-SSB resources in each S-SSB occasion in each carrier.The parameters for S-SSB transmission in one or multiple carriers may include the coverage requirement of S-SSB per carrier e.g., the number of S-SSB repetitions per transmission power level). For example, the WTRU may repeat more S-SSB if the power level of the S-SSB is low. Alternatively, the WTRU may transmit fewer S-SSB if the power level of S-SSB is larger. This configuration may ensure the coverage of S-SSB per carrier.

[0178] The parameters for S-SSB transmission in one or multiple carriers may include the minimum transmission power per S-SSB resource per carrier. This configuration may ensure the coverage per S- SSB transmission.

[0179] The parameters for S-SSB transmission in one or multiple carriers may include a primary carrier for S-SSB transmission. For example, the WTRU may be configured with a primary carrier for S-SSB transmission. The WTRU may prioritize transmitting S-SSB in the primary carrier. The WTRU may ensure the synchronization coverage in the primary carrier.

[0180] The WTRU may determine the priority associated with S-SSB transmission by first determining the priority associated with S-SSB transmission per carrier. The priority associated with S-SSB transmission per carrier may be used for prioritization among S-SSB in different carrier. The priority of S-SSB per carrier may be based on configurations from the network, and / or the SCS of the carrier. The WTRU may prioritize the carrier with lower SCS. The WTRU may prioritize the carrier with higher SCS.

[0181] The WTRU may determine the potential transmission power of S-SSB in each carrier in each S- SSB occasion. For each S-SSB occasion, the WTRU may first determine the transmission power of S-SSB per carrier based on the priority associated with the S-SSB. If the WTRU is configured with S-SSB resource in multiple carriers in the S-SSB occasion, the WTRU may sequentially allocate power for S-SSB in each carrier in the descending order of priority. The WTRU may confirm that the transmission level of high priority is satisfied before allocating power for a lower priority carrier. The WTRU may allocate equal power for each S-SSB with the same priority.

[0182] The WTRU may determine whether to transmit S-SSB in each carrier in one configured S-SSB occasion. The WTRU may then determine whether to transmit S-SSB in one carrier in one S-SSB occasion based on one or more of the allocated power for the S-SSB and / or the number of transmitted S-SSB occasions in the current synchronization period. The WTRU may determine to transmit S-SSB in one carrier if the allocated power for the S-SSB is larger than a configured threshold. Otherwise, the WTRU may not transmit S-SSB in this S-SSB occasion.

[0183] The WTRU may transmit S-SSB in the occasion if the number of transmitted S-SSB occasion in one synchronization period is smaller than a configured threshold (e.g., minimum number of S-SSB transmission occasion). Otherwise, if the number of transmitted S-SSB occasions in the synchronization period is larger than another configured threshold (e.g., maximum number of S-SSB transmission occasions), the WTRU may determine not to transmit S-SSB in the current and / or subsequent occasions in the synchronization period.

[0184] The WTRU may determine the number of S-SSB repetition per S-SSB occasion. The WTRU may then determine the number of S-SSB repetitions on one occasion based on the determined transmission power level and / or the configured number of S-SSB repetitions per power level. The WTRU may be configured with the number of S-SSB repetitions per transmission level of the S-SSB. The WTRU may then determine the transmission level of S-SSB based on the S-SSB prioritization procedure. The WTRU may then determine the number of S-SSB repetitions based the determined transmission level and / or the configured number of S-SSB repetitions associated with the power level. The WTRU may then indicate the number of S-SB repetitions in one of one or more S-SSB transmissions in one of the high priority carriers (e.g., in PBCH of S-SSB transmitted in the primary synchronization carrier). This approach may help other WTRUs aware of the number of repetitions in each carrier upon decoding synchronization transmission in the primary carrier.

[0185] The WTRU may perform S-SSB repetition. In S-SSB repetition, the WTRU may transmit multiple S-SSBs in one S-SSB occasions. This may help to increase the coverage of the S-SSB. The WTRU may determine whether to transmit multiple S-SSBs on one occasion based on the transmit power associated with each S-SSB. If the transmission power of the S-SSB is smaller than a configured threshold, the WTRU may transmit multiple S-SSB. Otherwise, if the transmit power of S-SSB is larger than the configured threshold, the WTRU may only transmit one S-SSB in the S-SSB occasion.

[0186] FIG. 5 depicts an example WTRU determination 500 of the number of S-SSB repetitions based on the transmission power level of S-SSB. As shown in FIG. 5, the WTRU may transmit S-SSB 504a-d in two carriers CC1 and CC2 502a-b, with CC1 502a acting as the primary carrier. For each S-SSB 504a-d occasion, the WTRU may determine transmission power of each S-SSB 504a-d in each carrier. In the S- SSB 504d occasion in CC2 502b without overlapping (e.g., non-overlapping) with S-SSB 504a-b in CC1 502a, the WTRU may transmit S-SSB 504d with full power. However, in the S-SSB 504c occasion in CC2 502b overlapping with S-SSB 504a-b in CC1 502a, the WTRU may reduce its transmission power since the WTRU shares power with S-SSB 504a transmission in CC1 502a. The WTRU may then determine thenumber of S-SSB 504c repetitions in CC2 502b based on the determined power level transmitted in each S-SSB 504c-d resource of CC2 502b. For example, in the S-SSB occasion having S-SSB overlapping with S-SSB on CC1 502a, the WTRU may transmit two S-SSBs 504a-b. However, in the S-SSB occasion without S-SSB overlapping on CC1 502a, the WTRU may transmit one S-SSB 504d once without repetition. This approach may help the WTRU in providing equal S-SSB coverage in the second carrier in all S-SSB occasions.

Claims

CLAIMS:What is claimed is:1 . A method performed by a first wireless transmit / receive unit (WTRU), the method comprising: determining a set of carriers and an overlapping duration threshold; transmitting a first physical sidelink control channel (PSCCH) or physical sidelink shared channel (PSSCH) transmission to reserve a PSCCH or PSSCH resource; and performing a pre-emption checking of the reserved PSCCH or PSSCH resource, wherein the preemption checking comprises: selecting one or more hybrid automatic repeat request (HARQ) disabled logical channels (LCHs) to multiplex a transport block (TB) to transmit in the PSCCH or PSSCH resource when the associated physical sidelink feedback channel (PSFCH) , overlaps and has different starting or ending symbols than the reserved PSCCH or PSSCH or an associated PSFCH of a second WTRU, wherein the second WTRU uses a carrier different that the carrier from the first WTRU; or selecting a different PSCCH or PSSCH resource when the reserved PSCCH or PSSCH resource or the associated PSFCH overlaps and has different starting or ending symbols than the reserved PSCCH or PSSCH or an associated PSFCH from the second WTRU; or puncturing or rate-matching during an overlap duration based on the reserved PSCCH or PSSCH resource or the associated PSFCH overlaps and has different starting or ending symbols than the reserved PSCCH or PSSCH or an associated PSFCH from the second WTRU.

2. The method of claim 1 , wherein the pre-emption checking comprises selecting the different PSCCH or PSSCH resource and transmitting a second PSSCH or PSCCH transmission in the different PSCCH or PSSCH resource.

3. The method of claim 1, wherein the pre-emption checking comprises selecting the different PSCCH or PSSCH resource based on the overlap duration being greater than the overlapping duration threshold.

4. The method of claim 1 , wherein the pre-emption checking comprises puncturing or ratematching during the overlap duration based on the overlap duration being less than the overlapping duration threshold.

5. The method of claim 1 , further comprising: determining a resource allocation carrier from the set of carriers, the resource allocation carrier comprising a subset of carriers for collaborative sensing; performing collaborative sensing on the subset of carriers for collaborative sensing carriers to determine sensing information; and determining a set of available resources of the resource allocation carrier based on the determined sensing information.

6. The method of claim 5, wherein determining a subset of carriers for collaborative sensing is associated with one or more of the number of carriers preconfigured with a set of collaborative sensing carriers, a set of carriers associated with the services actively performed by the WTRU, a number of indications from nearby WTRUs indicating a set of carriers available for collaborative sensing, and a set of carriers associated with destination ID triggering resource allocation, pre-emption, or resource re- evaluation.

7. The method of claim 1 , further comprising: performing an automatic gain control (AGC) avoidance procedure based on the determination confirming the reserved PSCCH or PSSCH transmission overlaps with a reserved resource from the second WTRU.

8. The method of claim 7, wherein the determination is further based on one or more of a measured reference signal received power (RSRP) of a transmission reserving a potential PSCCH or PSSCH transmission, a priority associated with the reserved PSCCH or PSSCH resource, a priority associated with the potential PSCCH or PSSCH transmission, a relative priority between the reserved PSCCH or PSSCH resource and a reserved PSCCH or PSSCH resource of the second WTRU associated with the potential transmission, or the earlier of the reserved PSCCH or PSSCH resource or the reserved PSCCH or PSSCH resource of the second WTRU associated with the potential transmission.

9. The method of claim 1 , wherein the pre-emption checking is based on one or more of a priority associated with the reserved PSCCH or PSSCH resource, a priority associated with a potential transmission, or a relative priority between the reserved PSCCH or PSSCH resource and a reserved resource of the second WTRU associated with the potential transmission.

10. The method of claim 1 , further comprising: disabling HARQ feedback if the associated PSFCH transmission overlaps with a potential transmission from the second WTRU and has different staring or ending symbol than a starting or ending symbol of the potential transmission from the second WTRU.

11. A first wireless transmit / receive unit (WTRU) comprising a processor and a memory, the processor and memory configured to: determine a set of carriers and an overlapping duration threshold; transmit a first physical sidelink control channel (PSCCH) or physical sidelink shared channel (PSSCH) transmission to reserve a PSCCH or PSSCH resource; and perform a pre-emption checking of the reserved PSCCH or PSSCH resource, wherein the preemption check comprises: select one or more hybrid automatic repeat request (HARQ) disabled logical channels (LCHs) to multiplex a transport block (TB) to transmit in the PSCCH or PSSCH resource when the associated physical sidelink feedback channel (PSFCH) overlaps and has different starting or ending symbols than the reserved PSCCH or PSSCH or an associated PSFCH of a second WTRU, wherein the second WTRU uses a carrier different that the carrier from the first WTRU; or select a different PSCCH or PSSCH resource when the reserved PSCCH or PSSCH resource or the associated PSFCH overlaps and has different starting or ending symbols than the reserved PSCCH or PSSCH or an associated PSFCH from the second WTRU; or puncture or rate-match during an overlap duration based on the reserved PSCCH or PSSCH resource or the associated PSFCH overlaps and has different starting or ending symbols than the reserved PSCCH or PSSCH or an associated PSFCH from the second WTRU.

12. The WTRU of claim 11 , wherein the pre-emption checking comprises selecting the different PSCCH or PSSCH resource and transmitting a second PSSCH or PSCCH transmission in the different PSCCH or PSSCH resource.

13. The WTRU of claim 11 , wherein the pre-emption checking comprises selecting the different PSCCH or PSSCH resource based on the overlap duration being greater than the overlapping duration threshold.

14. The WTRU of claim 11 , wherein the pre-emption checking comprises puncturing or ratematching during the overlap duration based on the overlap duration being less than the overlapping duration threshold.

15. The WTRU of claim 11 , the processor and memory further configured to: determine a resource allocation carrier from the set of carriers, the resource allocation carrier comprising a subset of carriers for collaborative sensing; perform collaborative sensing on the subset of carriers for collaborative sensing carriers to determine sensing information; and determine a set of available resources of the resource allocation carrier based on the determined sensing information.

16. The WTRU of claim 15, wherein the determination of a subset of carriers for collaborative sensing is associated with one or more of the number of carriers preconfigured with a set of collaborative sensing carriers, a set of carriers associated with the services actively performed by the WTRU, a number of indications from nearby WTRUs indicating a set of carriers available for collaborative sensing, and a set of carriers associated with destination ID triggering resource allocation, pre-emption, or resource re- evaluation.

17. The WTRU of claim 11 , the processor and memory further configured to: perform an automatic gain control (AGC) avoidance procedure based on the determination that confirms the reserved PSCCH or PSSCH transmission overlaps with a reserved resource from the second WTRU.

18. The WTRU of claim 17, wherein the determination is further based on one or more of a measured reference signal received power (RSRP) of a transmission reserving a potential PSCCH or PSSCH transmission, a priority associated with the reserved PSCCH or PSSCH resource, a priority associated with the potential PSCCH or PSSCH transmission, a relative priority between the reserved PSCCH or PSSCH resource and a reserved PSCCH or PSSCH resource of the second WTRU associated with the potential transmission, or the earlier of the reserved PSCCH or PSSCH resource or the reserved PSCCH or PSSCH resource of the second WTRU associated with the potential transmission.

19. The WTRU of claim 11 , wherein the pre-emption checking is based on one or more of a priority associated with the reserved PSCCH or PSSCH resource, a priority associated with a potential transmission, or a relative priority between the reserved PSCCH or PSSCH resource and a reserved resource of the second WTRU associated with the potential transmission.

20. The WTRU of claim 11 , the processor and memory further configured to: disable HARQ feedback if the associated PSFCH transmission overlaps with a potential transmission from the second WTRU and has different staring symbol than a starting or ending symbol of the potential transmission from another WTRU.

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