Methods, architectures, apparatuses, and systems for wideband operation for sidelink in unlicensed bands

Abstract

This disclosure relates to methods, architectures, apparatuses, and systems for broadband operation of sidechain communications in unlicensed frequency bands. In one embodiment, the method may be implemented in a wireless transmit / receive unit (WTRU). The method may include: receiving scheduling information from a network for one or more sidechain transmissions. The scheduling information may indicate a set of scheduled resources. The method may include: performing a listen-before-speak (LBT) operation on the set of scheduled resources to acquire a subset of resources in the set of scheduled resources. The method may include: transmitting sidechain control information indicating the acquired subset of resources. The method may include: transmitting data on the acquired subset of resources. The method may include: transmitting feedback information related to the one or more sidechain transmissions to the network based on a ratio between the number of acquired resources and the number of scheduled resources.

Description

[0001] This application is a divisional application. The parent application is entitled "Method, Architecture, Apparatus and System for Broadband Operation of Sidechains in Unlicensed Frequency Bands", filed on August 1, 2023, with application number 202380071118.0.

[0002] Cross-reference to related applications This application claims the benefit of U.S. Patent Application No. 63 / 395,627, filed August 5, 2022; U.S. Patent Application No. 63 / 445,551, filed February 14, 2023; and U.S. Patent Application No. 63 / 468,619, filed May 24, 2023, each of which is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure relates to wireless communications. For example, one or more embodiments disclosed herein relate to methods, architectures, apparatuses, and systems for broadband operation of sidechain communications in unlicensed frequency bands. Background Technology

[0004] In unlicensed frequency bands, the channel access process prior to transmission allows for the fair sharing of unlicensed spectrum among different radio access technologies. The embodiments described herein have been designed with the above in mind. Summary of the Invention

[0005] This document describes methods, architectures, apparatuses, and systems relating to broadband operation of sidechain communications in unlicensed frequency bands. In one embodiment, a method implemented in a Wireless Transmit / Receive Unit (WTRU) is described. The method may include: receiving scheduling information from a network for one or more sidechain transmissions. The scheduling information may indicate a set of scheduled resources. The method may include: performing Listen-Before-Speak (LBT) on the set of scheduled resources to acquire a subset of resources in the set of scheduled resources. The method may include: transmitting sidechain control information indicating the acquired subset of resources. The method may include: transmitting data in the acquired subset of resources. The method may include: transmitting feedback information related to the one or more sidechain transmissions to the network based on the number of acquired resources and the number of scheduled resources (e.g., a ratio between them).

[0006] In one embodiment, this document describes a WTRU including a processor and transmitters and receivers (e.g., transceivers) operatively coupled to the processor. The WTRU can be configured to: receive scheduling information from a network for one or more sidechain transmissions. The scheduling information may indicate a set of scheduled resources. The WTRU can be configured to perform LBT (Local Level Bypass) within the set of scheduled resources to acquire a subset of resources in the set of scheduled resources. The WTRU can be configured to: transmit sidechain control information indicating the acquired subset of resources. The WTRU can be configured to: transmit data within the acquired subset of resources. The WTRU can be configured to: transmit feedback information related to the one or more sidechain transmissions to the network based on a ratio between the number of acquired resources and the number of scheduled resources (e.g., between these ratios). Attached Figure Description

[0007] A more detailed understanding can be obtained from the following detailed embodiments, given by way of example in conjunction with the accompanying drawings. Like the detailed embodiments, the figures in these drawings are exemplary. Therefore, the figures and detailed embodiments should not be considered limiting, and other equivalently effective examples are possible and desirable. Furthermore, similar reference numerals (“references”) in the figures (“Figures”) indicate similar elements, and wherein: Figure 1A This is a system diagram illustrating an example communication system; Figure 1B It is illustrated in the diagram. Figure 1A The diagram shows a system diagram of an example wireless transmit / receive unit (WTRU) used in a communication system. Figure 1C It is illustrated in the diagram. Figure 1A The diagram shows a system diagram of an example radio access network (RAN) and an example core network (CN) used in a communication system. Figure 1D It is illustrated in the diagram. Figure 1A The diagram shows a further example RAN and a further example CN used in the communication system. Figure 2 This is a diagram illustrating a sample resource pool for SL U; Figure 3 It is a diagram illustrating several LBTs or transmission schemes for a SLU for a Transport Block (TB); Figure 4 This diagram illustrates several LBT or transmission schemes for a SL U with multiple TBs. Figure 5 This is a resource diagram illustrating the selection of resources for LBT or transmission schemes; Figure 6This is a resource graph illustrating the selection of resources used to perform adjacency LBT; Figure 7 This is a resource diagram illustrating the selection of resources for performing LBT using puncturing / rate matching with channel occupancy time (COT) of another WTRU; Figure 8 This is a resource map illustrating how a WTRU stops transmitting in a time slot before another WTRU's reserved COT to help that other WTRU acquire the channel; Figure 9 This is a resource map illustrating how WTRU postpones transmission to a future time slot after LBT is successfully implemented; Figure 10 This is a diagram illustrating the selection of the set of time slots available for LBT and transmission; Figure 11 It is a diagram illustrating whether the reserved resources are available or unavailable for LBT and transmission. Figure 12 This is a diagram illustrating the WTRU process after LBT and transmission fail to be performed in a time slot; Figure 13 It is a diagram illustrating the determination of available time slots for broadband transmission; Figure 14 This is a diagram illustrating the determination of the Access Priority Class (CAPC) of the channel to be used based on the maximum (e.g., pre) configuration amount data of the access channel; Figure 15 It is a resource map illustrating different transmission schemes and guard band utilization for broadband operations; Figure 16 This is a diagram illustrating an example method for reselecting LBT subbands for wideband sidechain transmission in unlicensed spectrum; Figure 17 This is a diagram illustrating an example method for broadband sidechain transmission in unlicensed spectrum; Figure 18 This is a diagram illustrating an example method for selecting resources to perform LBT for wideband sidechain transmission in unlicensed spectrum; Figure 19 This is a diagram illustrating an example method for reporting feedback information related to SL transmissions to the network; Figure 20 This is a diagram illustrating an example method for determining whether to retain the current LBT subband or select another LBT subband; Figure 21 This is a diagram illustrating an example method for determining the main LBT subband; Figure 22 This is a diagram illustrating an example method for selecting a time slot in a resource selection window; and Figure 23 This is a diagram illustrating an example method for transmission in the first start symbol of a time slot with multiple start symbols. Detailed Implementation

[0008] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, processes, components, and circuits have not been described in detail so as not to obscure the following description. Furthermore, embodiments and examples not specifically described herein may be practiced in place of or in combination with the embodiments and other examples described, disclosed, or otherwise explicitly, implicitly, and / or inherently provided herein (collectively, the “Provided”).

[0009] Although this document describes and / or claims various embodiments in which apparatuses, systems, devices, etc. and / or any elements thereof implement operations, processes, algorithms, functions, etc. and / or any part thereof, it should be understood that any embodiment described and / or claimed herein may configure any apparatus, system, device, etc. and / or any element thereof to implement any operation, process, algorithm, function, etc. and / or any part thereof.

[0010] Example Communication System The methods, apparatus, and systems provided herein are well-suited for communications involving both wired and wireless networks. Wired networks are well-known. Regarding... Figure 1A-1D This provides an overview of various types of wireless devices and infrastructures, in which various elements of the network can utilize the methods, apparatuses and systems provided herein, perform the methods, apparatuses and systems provided herein, are arranged according to the methods, apparatuses and systems provided herein, and / or are adapted and / or configured for the methods, apparatuses and systems provided herein.

[0011] Figure 1AThis diagram illustrates an example communication system 100 in which one or more of the disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content (such as voice, data, video, messaging, broadcasting, etc.) to multiple wireless users. The communication system 100 enables multiple wireless users to access such content by sharing system resources (including wireless bandwidth). For example, the communication system 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 Extended OFDM (ZT UW DTS-s OFDM), Unique Word OFDM (UW-OFDM), Resource Block Filtered OFDM, Filter Bank Multicarrier (FBMC), etc.

[0012] like Figure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, Public Switched Telephone Network (PSTN) 108, Internet 110, and other networks 112. Although it will be appreciated, the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, and 102d can be any type of device configured to operate and / or communicate in a wireless environment. As an example, WTRUs 102a, 102b, 102c, and 102d (any of which may be referred to as a “station” and / or “STA”) may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain scenarios), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. Any of WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0013] The communication system 100 may also include base station 114a and / or base station 114b. Each of base stations 114a and 114b may be any type of device configured to wirelessly interface with at least one of WTRUs 102a, 102b, 102c, and 102d to facilitate access to one or more communication networks, such as CN 106 / 115, the Internet 110, and / or other networks 112. As an example, base stations 114a and 114b may be any of a base transceiver station (BTS), Node-B, eNode B, home node B, home eNode B, gNB, NR NodeB, site controller, access point (AP), wireless router, etc. Although base stations 114a and 114b are depicted as single elements, it will be understood that base stations 114a and 114b may include any number of interconnected base stations and / or network elements.

[0014] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as base station controllers (BSCs), radio network controllers (RNCs), relay nodes, etc. Base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as cells (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a specific geographic area for a radio service, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Therefore, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology, and multiple transceivers may be used for each sector of the cell. For example, beamforming can be used to transmit and / or receive signals in a desired spatial direction.

[0015] Base stations 114a and 114b can communicate with one or more of WTRUs 102a, 102b, 102c, and 102d via air interface 116, which can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, millimeter wave, infrared (IR), ultraviolet (UV), visible light, etc.). Air interface 116 can be established using any suitable radio access technology (RAT).

[0016] More specifically, as noted above, the communication system 100 can be a multiple access system and can employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, base station 114a in RAN 104 / 113, and WTRUs 102a, 102b, and 102c can implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can use Wideband CDMA (WCDMA) to establish the air interface 116. WCDMA may include communication protocols such as High-Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed ​​Downlink Packet Access (HSDPA) and / or High-Speed ​​Uplink Packet Access (HSUPA).

[0017] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which can use Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro) to establish air interface 116.

[0018] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as NR radio access, which can use a new radio (NR) to establish an air interface 116.

[0019] In one embodiment, base station 114a and WTRUs 102a, 102b, and 102c can implement multiple radio access technologies. For example, base station 114a and WTRUs 102a, 102b, and 102c can jointly implement LTE radio access and NR radio access, for example, using the dual connectivity (DC) principle. Therefore, the air interface utilized by WTRUs 102a, 102b, and 102c can be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., eNBs and gNBs).

[0020] In other embodiments, base station 114a and WTRUs 102a, 102b, 102c can implement the following radio technologies, such as IEEE 802.11 (i.e., WiFi), IEEE 802.16 (i.e., WiMAX), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Provisional Standard 2000 (IS-2000), Provisional Standard 95 (IS-95), Provisional Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data Rate GSM Evolution (EDGE), GSMEDGE (GERAN), etc.

[0021] Figure 1A Base station 114b can be, for example, a wireless router, a home node B, a home eNode B, or an access point, and can utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a commercial area, home, vehicle, campus, industrial facility, air corridor (e.g., for drone use), road, etc. In one embodiment, base station 114b and WTRUs 102c, 102d can implement radio technologies such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, base station 114b and WTRUs 102c, 102d can implement radio technologies such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, base station 114b and WTRUs 102c, 102d can utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or femtocell. Figure 1A As shown, base station 114b may have a direct connection to Internet 110. Therefore, base station 114b may not be required to access Internet 110 via CN 106 / 115.

[0022] RAN 104 / 113 can communicate with CN 106 / 115, which can be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of WTRUs 102a, 102b, 102c, and 102d. Data may have different Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. CN 106 / 115 can provide call control, billing services, location-based services, prepaid calling, internet connectivity, video distribution, and / or perform advanced security functions, such as user authentication. Although... Figure 1AAlthough not shown, it will be understood that RAN104 / 113 and / or CN106 / 115 can communicate directly or indirectly with other RANs that use the same RAT as or a different RAT than RAN 104 / 113. For example, in addition to being connected to RAN 104 / 113, which can utilize NR radio technology, CN106 / 115 can also communicate with another RAN (not shown) that uses GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

[0023] CN 106 / 115 may also act as a gateway for WTRU 102a, 102b, 102c, 102d to access PSTN 108, the Internet 110, and / or other networks 112. PSTN 108 may include a circuit-switched telephone network providing Common Old-Style Telephone Service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices using common communication protocols such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) from the TCP / IP Internet Protocol suite. Network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, network 112 may include another CN connected to one or more RANs, which may use the same RAT as RAN 104 / 113 or a different RAT.

[0024] Some or all of the WTRUs 102a, 102b, 102c, and 102d in communication system 100 may include multi-mode capabilities (e.g., WTRUs 102a, 102b, 102c, and 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). For example, Figure 1A The WTRU 102c shown can be configured to communicate with a base station 114a that can use cellular-based radio technology and a base station 114b that can use IEEE 802 radio technology.

[0025] Figure 1B This is a system diagram illustrating example WTRU 102. (Example:) Figure 1B As shown, 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 supply 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138, etc. It will be appreciated that WTRU 102 may include any sub-combination of the above-described elements while remaining consistent with the embodiments.

[0026] Processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. Processor 118 may perform signal encoding, data processing, power control, input / output processing, and / or any other functions that enable WTRU 102 to operate in a wireless environment. Processor 118 may be coupled to transceiver 120, which may be coupled to transmitting / receiving element 122. Although... Figure 1B The processor 118 and transceiver 120 are depicted as separate components, but it will be understood that the processor 118 and transceiver 120 can be integrated together in an electronic package or chip.

[0027] Transmitting / receiving element 122 can be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via air interface 116. For example, in one embodiment, transmitting / receiving element 122 can be an antenna configured to transmit and / or receive RF signals. In one embodiment, transmitting / receiving element 122 can be a transmitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In yet another embodiment, transmitting / receiving element 122 can be configured to transmit and / or receive both RF and optical signals. It will be appreciated that transmitting / receiving element 122 can be configured to transmit and / or receive any combination of wireless signals.

[0028] Although the transmitting / receiving element 122 is in Figure 1B While depicted as a single element, WTRU 102 may include any number of transmitting / receiving elements 122. More specifically, WTRU 102 may employ MIMO technology. Thus, in one embodiment, WTRU 102 may include two or more transmitting / receiving elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via air interface 116.

[0029] Transceiver 120 can be configured to modulate signals to be transmitted by transmitting / receiving element 122 and demodulate signals received by transmitting / receiving element 122. As noted above, WTRU 102 can have multi-mode capability. Thus, for example, transceiver 120 may include multiple transceivers for enabling WTRU 102 to communicate via multiple RATs (such as NR and IEEE 802.11).

[0030] The processor 118 of WTRU 102 can be coupled to the speaker / microphone 124, keypad 126, and / or display / touchpad 128 (e.g., a liquid crystal display (LCD) unit or an organic light-emitting diode (OLED) display unit), and can receive user input data from them. The processor 118 can also output user data to the speaker / microphone 124, keypad 126, and / or display / touchpad 128. Additionally, the processor 118 can access information from any type of suitable memory (such as non-removable memory 130 and / or removable memory 132), and store data in that memory. Non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), hard disk, or any other type of memory storage device. Removable memory 132 may include a subscriber identity module (SIM) card, memory stick, secure digital storage (SD) card, etc. In other embodiments, processor 118 may access information from memory that is not physically located on WTRU 102 (such as on a server or home computer (not shown)) and store data in that memory.

[0031] The processor 118 can receive power from the power supply 134 and can be configured to distribute and / or control the power going to other components in the WTRU 102. The power supply 134 can be any suitable device for powering the WTRU 102. For example, the power supply 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, etc.

[0032] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) about the current location of the WTRU 102. In addition to, or instead of, information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) via air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be understood that the WTRU 102 may acquire location information using any suitable location determination method, while remaining consistent with the embodiments.

[0033] The processor 118 may be further coupled to other peripherals 138, which may include one or more software and / or hardware modules providing additional features, functions, and / or wired or wireless connectivity. For example, components 138 may include accelerometers, electronic compasses, satellite transceivers, digital cameras (for photos and / or videos), Universal Serial Bus (USB) ports, vibration devices, television transceivers, hands-free headsets, Bluetooth® modules, FM radio units, digital music players, media players, video game player modules, internet browsers, virtual reality and / or augmented reality (VR / AR) devices, activity trackers, etc. Peripherals 138 may include one or more sensors, which may be one or more of the following: gyroscopes, accelerometers, Hall effect sensors, magnetometers, orientation sensors, proximity sensors, temperature sensors, time sensors, geolocation sensors, altimeters, light sensors, touch sensors, magnetometers, barometers, gesture sensors, biometric sensors, and / or humidity sensors.

[0034] WTRU 102 may include a full-duplex radio, for which the transmission and reception of some or all signals (e.g., associated with specific subframes for both uplink (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 to reduce and / or substantially eliminate self-interference via hardware (e.g., a choke) or via signal processing (e.g., a separate processor (not shown) or via processor 118). In one embodiment, WTRU 102 may include a half-duplex radio, for which the transmission and reception of some or all signals (e.g., associated with specific subframes for either uplink (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0035] Figure 1C The diagram illustrates a system diagram of RAN 104 and CN 106 according to an embodiment. As noted above, RAN 104 can employ E-UTRA radio technology to communicate with WTRUs 102a, 102b, and 102c via air interface 116. RAN 104 can also communicate with CN 106.

[0036] RAN 104 may include eNode-Bs 160a, 160b, and 160c, although it will be understood that RAN 104 may include any number of eNode-Bs while remaining consistent with the embodiments. eNode-Bs 160a, 160b, and 160c may each include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In one embodiment, eNode-Bs 160a, 160b, and 160c may implement MIMO technology. Therefore, eNode-B 160a may, for example, use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a.

[0037] Each of the eNode-B 160a, 160b, and 160c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, and user scheduling in the uplink (UL) and / or downlink (DL). For example... Figure 1C As shown, eNode-B 160a, 160b, and 160c can communicate with each other via the X2 interface.

[0038] Figure 1C The CN 106 shown may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (or PGW) 166. Although each of the foregoing elements is depicted as part of CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than a CN operator.

[0039] The MME 162 can connect to each of the eNode-Bs 160a, 160b, and 160c in RAN104 via the S1 interface and can act as a control node. For example, the MME 162 can be responsible for authenticating users of WTRUs 102a, 102b, and 102c, bearer activation / deactivation, selecting a specific serving gateway during the initial attachment of WTRUs 102a, 102b, and 102c, etc. The MME 162 can provide control plane functions for handover between RAN104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0040] The SGW 164 can connect to each of the eNode Bs 160a, 160b, and 160c in RAN104 via the S1 interface. The SGW 164 can typically route and forward user data packets to / from WTRUs 102a, 102b, and 102c. The SGW 164 can perform other functions, such as anchoring the user plane during inter-eNode B handover, triggering paging when DL data is available for WTRUs 102a, 102b, and 102c, and managing and storing the context of WTRUs 102a, 102b, and 102c.

[0041] SGW 164 can be connected to PGW 166, which can provide WTRU 102a, 102b, 102c with access to packet-switched networks (such as Internet 110) to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices.

[0042] CN 106 facilitates communication with other networks. For example, CN 106 can provide WTRUs 102a, 102b, and 102c with access to a circuit-switched network (such as PSTN 108) to facilitate communication between WTRUs 102a, 102b, and 102c and conventional terrestrial line communication equipment. For example, CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between CN 106 and PSTN 108. Additionally, CN 106 can provide WTRUs 102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0043] Despite WTRU in Figures 1A to 1D While described as a wireless terminal, it is envisioned that, in some representative embodiments, such a terminal may use (e.g., temporarily or permanently) a wired communication interface with a communication network.

[0044] In a representative embodiment, the other network 112 may be a WLAN.

[0045] In an Infrastructure Basic Services Set (BSS) mode, a WLAN may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic into and / or out of the BSS. Traffic originating outside the BSS destined for a STA can be delivered to the STA via the AP. Traffic from a STA to a destination outside the BSS can be sent to the AP for delivery to the appropriate destination. Traffic between STAs within the BSS can be sent via the AP, for example, where a source STA can send traffic to the AP, and the AP can deliver the traffic to the destination STA. Traffic between STAs within the BSS can be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic can be sent between source and destination STAs (e.g., directly between them) using a direct link setup (DLS). In some representative embodiments, the DLS may use 802.11e DLS or 802.11z Tunneled DLS (TDLS). A WLAN using the Standalone BSS (IBSS) mode may not have an access point (AP), and STAs within or using the IBSS (e.g., all STAs) can communicate directly with each other. The IBSS communication mode may sometimes be referred to as a "self-organizing" communication mode in this document.

[0046] When using 802.11ac infrastructure operation mode or a similar operation mode, the AP can transmit beacons on a fixed channel, such as a primary channel. The primary channel can be of fixed width (e.g., a bandwidth of 20 MHz) or dynamically set via signaling. The primary channel can be the operating channel of the BSS and can be used by STAs to establish connections with the AP. In some representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) can be implemented, for example, in an 802.11 system. For CSMA / CA, STAs including the AP (e.g., each STA) can sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, that STA can back off. A STA (e.g., only one station) can transmit at any given time within a given BSS.

[0047] High-throughput (HT) STAs can communicate using a 40MHz wide channel, for example, by combining a primary 20MHz channel with adjacent or non-adjacent 20MHz channels to form a 40MHz wide channel.

[0048] Very High Throughput (VHT) STAs can support channels with widths of 20MHz, 40MHz, 80MHz, and / or 160MHz. 40MHz and / or 80MHz channels can be formed by combining consecutive 20MHz channels. A 160MHz channel can be formed by combining eight consecutive 20MHz channels or by combining two non-consecutive 80MHz channels (which can be referred to as an 80+80 configuration). For the 80+80 configuration, after channel coding, data is transmitted via a segment resolver that divides the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time-domain processing can be performed separately on each stream. The streams can be mapped onto two 80MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the above operations for the 80+80 configuration can be reversed, and the combined data can be sent to the Media Access Control (MAC).

[0049] Operating modes below 1 GHz are supported by 802.11af and 802.11ah. The channel operating bandwidth and carrier are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV white space (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to representative embodiments, 802.11ah can support instrument-type control / machine-type communications, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support) certain and / or limited bandwidths. MTC devices may include batteries with a lifespan exceeding a threshold (e.g., to maintain a very long battery life).

[0050] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include a channel that can be designated as the primary channel. The primary channel can have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or limited by the STA that supports the minimum bandwidth operating mode among all STAs operating in the BSS. In the 802.11ah example, for STAs that support (e.g., only support) the 1MHz mode (e.g., MTC type devices), the primary channel can be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings can depend on the status of the primary channel. If the primary channel is busy, for example because an STA (which only supports the 1MHz operating mode) is transmitting to the AP, the entire available band may be considered busy, even if most of the band is still idle and could be available.

[0051] In the United States, the available frequency band for 802.11ah is from 902MHz to 928MHz. In South Korea, the available frequency band is from 917.5MHz to 923.5MHz. In Japan, the available frequency band is from 916.5MHz to 927.5MHz. Depending on the country code, the total available bandwidth for 802.11ah is 6MHz to 26MHz.

[0052] Figure 1D The diagram illustrates a system diagram of RAN 113 and CN 115 according to an embodiment. As noted above, RAN 113 may employ NR radio technology to communicate with WTRUs 102a, 102b, and 102c via air interface 116. RAN 113 may also communicate with CN 115.

[0053] RAN 113 may include gNBs 180a, 180b, and 180c, although it will be understood that RAN 113 may include any number of gNBs while remaining consistent with the embodiments. gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In one embodiment, gNBs 180a, 180b, and 180c may implement MIMO technology. For example, gNBs 180a and 180b may utilize beamforming to transmit signals to and / or receive signals from WTRUs 102a, 102b, and 102c. Therefore, gNB 180a may, for example, use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a. In one embodiment, gNBs 180a, 180b, and 180c can implement carrier aggregation technology. For example, gNB 180a can transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers can be on unlicensed spectrum, while the remaining component carriers can be on licensed spectrum. In one embodiment, gNBs 180a, 180b, and 180c can implement Cooperative Multipoint (CoMP) technology. For example, WTRU 102a can receive cooperative transmissions from gNBs 180a and 180b (and / or gNB 180c).

[0054] WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using transmissions associated with scalable digitization. For example, OFDM symbol spacing and / or OFDM subcarrier spacing can vary depending on different transmissions, different cells, and / or different portions of the radio transmission spectrum. WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using subframes of various or scalable lengths or transmission time intervals (TTIs) (e.g., containing different numbers of OFDM symbols and / or absolute times of varying durations).

[0055] gNBs 180a, 180b, and 180c can be configured to communicate with WTRUs 102a, 102b, and 102c in standalone and / or non-standalone configurations. In standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c without also accessing other RANs (e.g., eNode-Bs 160a, 160b, and 160c). In standalone configuration, WTRUs 102a, 102b, and 102c can utilize one or more of gNBs 180a, 180b, and 180c as mobility anchors. In standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using signals in unlicensed frequency bands. In a non-standalone configuration, WTRUs 102a, 102b, and 102c can communicate with / connect to gNBs 180a, 180b, and 180c, and simultaneously communicate with / connect to another RAN (such as eNode-Bs 160a, 160b, and 160c). For example, WTRUs 102a, 102b, and 102c can implement DC principles to communicate substantially simultaneously with one or more gNBs 180a, 180b, and 180c and one or more eNode-Bs 160a, 160b, and 160c. In a non-standalone configuration, eNode-B 160a, 160b, and 160c can act as mobility anchors for WTRU 102a, 102b, and 102c, and gNB 180a, 180b, and 180c can provide additional coverage and / or throughput to serve WTRU 102a, 102b, and 102c.

[0056] Each of gNBs 180a, 180b, and 180c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in the uplink (UL) and / or (DL), network slicing support, dual connectivity, interoperability between NR and E-UTRA, routing of user plane data to User Plane Functions (UPF) 184a and 184b, routing of control plane information to Access and Mobility Management Functions (AMF) 182a and 182b, etc. Figure 1D As shown, gNB 180a, 180b, and 180c can communicate with each other via the Xn interface.

[0057] Figure 1DThe CN 115 shown may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and may include a Data Network (DN) 185a, 185b. Although each of the foregoing elements is depicted as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0058] AMF 182a and 182b can connect to one or more of the gNBs 180a, 180b, and 180c in RAN 113 via the N2 interface and can act as control nodes. For example, AMF 182a and 182b can be responsible for authenticating users of WTRU 102a, 102b, and 102c, supporting network slicing (e.g., handling different Protocol Data Unit (PDU) sessions with different requirements), selecting specific SMF 183a and 183b, managing registration areas, terminating Non-Access Stratum (NAS) signaling, mobility management, etc. Network slices can be used by AMF 182a and 182b to customize CN support for WTRU 102a, 102b, and 102c based on the service types utilized by WTRU 102a, 102b, and 102c. For example, different network slices can be built for different use cases, such as services that rely on Ultra Reliable Low Latency (URLLC) access, services that rely on Enhanced Massive Mobile Broadband (eMBB) access, and services for Machine Type Communication (MTC) access. AMF 182a and 182b can provide control plane functions for handover between 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.

[0059] SMFs 183a and 183b can connect to AMFs 182a and 182b in CN 115 via the N11 interface. SMFs 183a and 183b can also connect to UPFs 184a and 184b in CN 115 via the N4 interface. SMFs 183a and 183b can select and control UPFs 184a and 184b, and configure traffic routing through UPFs 184a and 184b. SMFs 183a and 183b can perform other functions, such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, and providing downlink data notifications. PDU session types can be IP-based, non-IP-based, Ethernet-based, etc.

[0060] UPF 184a and 184b can connect to one or more of gNBs 180a, 180b, and 180c in RAN 113 via the N3 interface. These gNBs can provide WTRU 102a, 102b, and 102c with access to a packet-switched network (such as the Internet 110) to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices. UPF 184a and 184b can perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, and providing mobility anchoring.

[0061] CN 115 can facilitate communication with other networks. For example, CN 115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between CN 115 and PSTN 108. Additionally, CN 115 can provide WTRUs 102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRUs 102a, 102b, and 102c can connect to local data networks (DNs) 185a and 185b via the N3 interface to UPFs 184a and 184b and the N6 interface between UPFs 184a and 184b and DNs 185a and 185b.

[0062] Given Figures 1A to 1D as well as Figures 1A to 1D The corresponding descriptions may be performed by one or more emulation devices (not shown) to perform one or more of the functions described herein with respect to one or more of the following: WTRU102a-d, base station 114a-b, eNode-B 160a-c, MME 162, SGW164, PGW 166, gNB 180a-c, AMF182a-b, UPF184a-b, SMF 183a-b, DN 185a-b, and / or one or more other devices described herein. An emulation device may be one or more devices configured to emulate one or more of the functions described herein. For example, an emulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0063] Simulation devices can be designed to perform tests on one or more other devices in a laboratory environment and / or a carrier network environment. For example, the one or more simulation devices can perform one or more or all of their functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. The one or more simulation devices can perform one or more or all of their functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. Simulation devices can be directly coupled to another device for testing purposes and / or can use over-the-air wireless communication to perform tests.

[0064] The one or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation devices can be used in test scenarios in a test laboratory and / or in non-deployed (e.g., testing) wired and / or wireless communication networks to perform testing on one or more components. The one or more simulation devices can be test rigs. Direct RF coupling and / or wireless communication via RF circuitry (e.g., which may include one or more antennas) can be used by the simulation devices to transmit and / or receive data.

[0065] Throughout the embodiments described herein, the terms "serving base station," "base station," "gNB," and "network," collectively referred to as "network," may be used interchangeably to identify any network element, such as a network element that acts as a serving base station, for example. The embodiments described herein are not limited to gNBs but are applicable to any other type of serving base station.

[0066] For clarity, throughout the embodiments described herein, satisfied and unsatisfied conditions, as well as configuration(s) condition(s) parameters, are described relative to a threshold (e.g., greater than or less than) a threshold value, configured to (e.g., a threshold) value, etc. For example, satisfied conditions may be described as being above (e.g., a threshold) value, and unsatisfied conditions (e.g., performance criteria) may be described as being below (e.g., a threshold) value. The embodiments described herein are not limited to threshold-based conditions. Any other kind of conditions(s) and parameters (such as, for example, belonging to or not belonging to a value range) may be applied to the embodiments described herein.

[0067] Throughout the embodiments described herein, (e.g., configuration) information can be described as being received by the WTRU from the network, for example, via system information or via any kind of protocol message. Although not explicitly mentioned throughout the embodiments described herein, the same (e.g., configuration) information can be pre-configured in the WTRU (e.g., via any kind of pre-configuration method, such as, for example, via factory settings) so that the (e.g., configuration) information can be used by the WTRU even if it is not received from the network.

[0068] Throughout the embodiments described herein, the statement "the WTRU can be configured with a set of parameters" is equivalent to, or can be used interchangeably with, "the WTRU can receive configuration information indicating the set of parameters (e.g., from another network element (e.g., a gNB))". Similarly, throughout the embodiments described herein, the statement "the WTRU can report something" and "the WTRU can be configured to report something" is equivalent to, or can be used interchangeably with, "the WTRU can transmit (e.g., report) information indicating something".

[0069] In the embodiments described herein, the term Uu is used to refer to any of the data, transmissions, interfaces, features, etc., associated with the (uplink / downlink) link to the base station.

[0070] Operations in unlicensed spectrum This article describes operations in unlicensed spectrum.

[0071] SL operations in unlicensed spectrum At the 3GPP RAN #94 meeting, it was agreed that the R18 Sidechain (SL) Evolution Work Item (WI) includes a study on support for sidechain operations for both Mode 1 and Mode 2 in unlicensed spectrum within Frequency Range 1 (FR1) (Sidechain Unlicensed). The unlicensed SL bands are 5 GHz and 6 GHz, and Uu operations associated with Mode 1 are limited to licensed spectrum. Sidechain Unlicensed (SL U) channel access designs can be based on regional regulatory requirements regarding existing 5G New Radio Unlicensed (NR U) channel access as a starting point.

[0072] The R16 SL resource allocation mechanism specified for licensed spectrum can be reused. The scope of R18 SL U also covers changes to the NR SL physical (PHY) channel structure and procedures for operation in unlicensed spectrum. For example, the Hybrid Automatic Repeat Request (HARQ) feedback supported in the new Radio Vehicle to Everything (NR V2X) for unicast and multicast transmissions will be evaluated in the R18WI discussion.

[0073] Unlicensed requirements for a single LBT subband In unlicensed frequency bands, the channel access process prior to transmission can allow for fair sharing of unlicensed spectrum among different radio access technologies. Channel access can utilize a Listen-Before-Speak (LBT) process. The LBT process can be described as a mechanism through which equipment can apply a Clear Channel Assessment (CCA) check before using the channel. CCA can utilize at least energy detection to determine the presence or absence of other signals on the channel, thus determining whether the channel is occupied or cleared. For some LBT types (e.g., Type 2 LBT), a fixed sensing duration of 16 or 25 μs can be used to clear the channel. For other LBT types (e.g., Type 1 LBT), a random number of sensing slots (e.g., each sensing slot spanning 9 μs) can be used to clear the channel, this random number being referred to as N. For example, if the channel is idle for the duration required for each sensing type (e.g., associated with each sensing type), the WTRU can perform a transmission.

[0074] There may be four channel access types defined by regulations (which may be referred to as LBT types in this document), such as, for example, type 1 channel access, type 2A channel access, type 2B channel access and type 2C channel access.

[0075] In Type 1 channel access, the transmitter can transmit after sensing the channel as idle for N sensing time slots, where N can be a number (e.g., randomly selected). Whenever the channel is sensed as busy in one of the N time slots, sensing can be performed for an additional delay duration.

[0076] In Type 2A channel access, the transmitter can transmit after sensing the channel as idle for at least 25 microseconds (e.g., immediately).

[0077] In Type 2B channel access, the transmitter can transmit after sensing the channel as idle for at least 16 microseconds (e.g., immediately).

[0078] In Type 2C channel access, the transmitter may not need to sense the channel before transmission.

[0079] After a transmitter may have already acquired the channel, it may occupy the channel for a Channel Occupied Time (COT) period (e.g., perform a transmission in the channel). The COT may have an upper bound (e.g., a maximum) duration, depending on which LBT type can be used to acquire the channel. A transmitter may initiate a COT and may share it with another transmitter under certain restrictions (e.g., conditions), such as using LBT type 1 to initially acquire the channel, and the gap between different transmissions may be smaller than (e.g., a specified) gap.

[0080] Broadband operations in Uu without permission: In unlicensed spectrum, an example of bandwidth for a single LBT subband could be 20 MHz. Wideband operation in unlicensed spectrum can be used to refer to the operation of network elements with bandwidth greater than 20 MHz (e.g., multiple LBT subbands). Wideband operation allows WTRUs to obtain greater bandwidth and achieve higher throughput.

[0081] R 16 NR Uu supports two types of gNB channel access for wideband operation, referred to as Type A and Type B wideband channel access. In Type A, the gNB can maintain an individual LBT process for each LBT subband and can perform transmissions in each LBT subband if the LBT is successful. Type A can be divided into two subtypes, referred to as Type A1 and Type A2. In Type A1, a back-off counter N can be initiated per LBT subband. In Type A2, a single back-off counter N can be used for all LBT subbands. In Type B, the gNB can select one LBT subband (e.g., cj) for Type 1 LBT and select the remaining LBT subbands (e.g., sensed before Tx in LBT subband cj) for Type 2 LBT (e.g., 2B). T mc = 25μs). The gNB can transmit in LBT subband cj and in any subband ci, for which type 2 LBT may have been successful (e.g., the channel was found to be empty). Type B can be divided into types B1 and B2. In type B1, a single contention window (CW) can be maintained for all LBT subbands. p Furthermore, in type B2, an individual competition window (CW) can be maintained for each LBT subband. p ).

[0082] For UL operation, the Wideband Physical Uplink Idle Channel (PUSCH) can be used to schedule the WTRU, and if the LBT is successful in all scheduled LBT subbands, the WTRU can perform a PUSCH transmission. This constraint allows the network to avoid blind detection of transmissions from the WTRU due to unpredictable LBT results.

[0083] To mitigate intra-carrier interference between transmissions in different LBT subbands between Wi-Fi and NR U, a guard band can be introduced between two adjacent LBT subbands. This guard band can be semi-statically configured or predefined (e.g., in 3GPP TS38.101). If a zero guard band is configured, the gNB cannot perform a transmission if it fails to acquire any LBT subband in the carrier. If the WTRU acquires two adjacent LBT subbands, the guard band between the two LBT subbands can be used.

[0084] NR V2X Mode 1 Scheduling: For Mode 1 dynamic scheduling, the network can schedule WTRUs for a sidechain grant for a TB of transmission. The network can indicate the UL resource to be used for feedback granting (e.g., transmit information indicating it). For example, if a WTRU uses a grant to transmit a HARQ-enabled TB, the WTRU can report ACK and / or NACK based on positive acknowledgment (ACK) / negative acknowledgment (NACK) feedback or discontinuous transmission (DTX) from the Rx WTRU. If a WTRU uses a grant to transmit a HARQ-disabled TB, the WTRU can report NACK if more resources are expected to be used to transmit the TB. Otherwise, the WTRU can report ACK.

[0085] In sidechain resource allocation, two scheduling modes can exist, which can be referred to in this paper as WTRU autonomous resource allocation (e.g., mode 2) and network scheduling (e.g., mode 1). For broadband operations in unlicensed spectrum of the sidechain, the WTRU can be (e.g., pre-)configured with multiple LBT subbands. This paper describes the mechanism used to perform LBT subband selection and resource allocation.

[0086] In an NR U, the gNB is a receiver for UL resources scheduled by the network. The gNB is aware of the UL transmission status. In a sidechain, the network may not be aware of SL transmissions in the sidechain resources it schedules. This paper describes a mechanism for coordinating sidechain scheduling between the gNB and WTRU to address the unpredictability of the LBT process.

[0087] If the WTRU acquires two adjacent LBT subbands, it can be beneficial for the system and the WTRU to use the guard band between the two LBT subbands. The Rx WTRU may not be aware of this decision. This paper describes a mechanism for coordinating and optimizing the use of the guard band.

[0088] Two metrics can be used to characterize the channel state, allowing the WTRU to take action: Channel Busy Ratio (CBR) and Channel Occupancy Ratio (CR). The Channel Busy Ratio (CBR) can be considered as the portion of the resource pool where the received signal strength exceeds (e.g., a pre-)configured threshold. This metric can be sensed, for example, over the last hundred subframes / slots. The CBR provides an estimate of the overall channel state. The Channel Occupancy Ratio (CR), which can be determined at a subframe / slot (e.g., n), can be considered as the total number of subchannels used for transmissions in previous subframes / slots (e.g., [na, n-1]) and licensed in upcoming subframes / slots (e.g., [n, n+b]) divided by the total number of subchannels (e.g., within [na, n+b]), where a, b, and n can be integers determined by the WTRU. The CR provides an indication of channel utilization by the transmitter itself.

[0089] Method and apparatus for broadband operation in SLU In the embodiments described herein, the term "LBT subband" may be used interchangeably with "set of LBT subbands", "resource pool", "sidechain carrier", "bandwidth portion (BWP)", "subband" and "set of resource blocks (RB)".

[0090] In the embodiments described herein, the term "reserved resource" may be used to describe resources reserved for LBT and / or transmission. The term "resource" may be used interchangeably with the term "COT".

[0091] In the embodiments described herein, resources can be used to describe a collection of smaller resources, each of which can be used for a transmission.

[0092] In the embodiments described herein, “punching / re-matching the transmission” can be used interchangeably with the action of “determining the duration of a transmission”.

[0093] In the embodiments described herein, the Received Signal Strength Indicator (RSSI), Reference Received Power (RSRP), and Reference Received Quality (RSRQ) may be used interchangeably to refer to quality measures representing signal quality.

[0094] In the embodiments described herein, “Physical Sidechain Control Channel (PSCCH) / Physical Sidechain Shared Channel (PSSCH) transmission” can be used interchangeably with “SL transmission”.

[0095] In the embodiments described herein, the terms “number” and “percentage” collectively referred to as “number / percentage” can be used interchangeably to refer to a subset of resources within a set of resources, such as the ratio of resources on ...

[0096] Methods for autonomous resource allocation in WTRU LBT parameters In some embodiments, the WTRU may perform LBT before transmission. The WTRU may determine one or any combination of the following LBT parameters: • For LBT types with multi-channel access (e.g., LBT types A, A1, A2, B, B1, B2). • For LBT type accessed by an LBT subband channel (e.g., LBT type 1, 2, 2A, 2B, 2C). • The LBT category in an LBT subband (e.g., LBT CAT 1, 2, 4); • Access Priority Class (CAPC); • Contention window size, which may include the current contention window associated with channel access priority class p ( CW p ), lower bound (e.g., minimum) and / or upper bound (e.g., maximum) competition window (e.g., CW p , CW min,p and CW max,p ); • Either the current value or the initial value (N) of the backoff counter; • The duration of COT, which may include the current COT and / or the maximum COT; • Delayed period ( T d ); • LBT energy detection threshold used to determine channel availability; • Fixed Frame Period (FFP) configuration; and • Clear Channel Access (CCA) duration.

[0097] In this document, LBT parameters may include one or any combination of parameters related to the channel access procedure. Parameters may include, but are not limited to, the LBT type for multi-channel access, the LBT type for channel access in an LBT subband, the LBT category in an LBT subband, CAPC, and contention window size (which may include...). CWp , CW min,p and CW max,p ), Current or initial rollback counter N, COT duration, delay period, LBT energy detection, FFP configuration, and CCA duration.

[0098] WTRU determines the LBT parameters used for the access channel. In some embodiments, WTRU may determine one or any combination of LBT parameters based on one or any combination of the following two examples.

[0099] In the first example, the WTRU can determine any of the LBT parameters based on any of the QoS of the TB, the sidechain radio bearer (SLRB), and the logical channel (LCH). In this document, the QoS of the TB, SLRB, and / or LCH can include one or more of the following: priority, delay, reliability, range requirement, data rate, remaining packet delay budget (PDB), type of data traffic (e.g., whether the data is periodic or aperiodic), periodicity of traffic, type of HARQ feedback (e.g., whether the TB, SLRB, and / or LCH are HARQ enabled, disabled, or a mixture of both), type of TB cast (e.g., whether the TB, SLRB, and / or LCH are associated with unicast, multicast, and / or broadcast), size of the TB, remaining PDB (e.g., for TB retransmissions), and one or more LBT parameters used to access the channel to transmit the TB.

[0100] In the second example, the WTRU can determine any of the LBT parameters based on the TB size, the WTRU's buffer status, and the channel busy ratio (CBR) of the resource pool and / or LBT subband.

[0101] WTRU determines the resource size used to perform LBT and / or resource allocation. In one embodiment, the WTRU can determine the resource size for performing LBT and / or transmission. The resource size may include the bandwidth or minimum bandwidth and / or duration or minimum duration for each resource used to perform LBT and / or transmission. In one approach, the WTRU can perform LBT and / or transmission for resources having at least M consecutive sub-channels spanning at least N time slots, where M and N are integers. In another approach, the WTRU can perform LBT and / or transmission for resources having at least M consecutive LBT sub-bands spanning at least N time slots. This approach can be facilitated to optimize the number of access channel attempts.

[0102] exist Figure 2In one example shown, the WTRU can be (e.g., pre-)configured to perform transmissions in a resource pool with three LBT subbands. The WTRU can determine the size of resources to perform LBT and / or transmissions in which at least two adjacent LBT subbands span at least two time slots. The WTRU can then select resources in the rectangles shown at 201, 203, and 205, which may include resources for performing LBT and / or transmissions. The resources in the rectangles shown at 201, 203, and 205 satisfy the resource size requirement of at least (e.g., at least) two LBT subbands spanning at least (e.g., at least) two time slots.

[0103] WTRU can determine the resource size for performing LBT and / or transmission based on one or any combination of the following six examples (e.g., it may include any one of a minimum of M LBT subbands spanning at least N time slots).

[0104] In the first example, the WTRU can determine the resource size based on (e.g., pre)configuration in the resource pool. For example, the WTRU can be (e.g., pre)configured with M and / or N values ​​for performing LBT and / or transfers. The WTRU can then select the M and / or N values ​​based on the (pre)configuration.

[0105] In the second example, the WTRU can determine the resource size based on the TB size. For example, the WTRU can be (e.g., pre-)configured with a range of resource sizes (e.g., at least M LBT subbands spanning at least N time slots) for performing LBT and / or transmissions based on the TB size. The WTRU can (e.g., then) determine the M and / or N values ​​for performing LBT and / or transmissions based on the TB size.

[0106] In the third example, the WTRU can determine the resource size based on the CBR of the resource pool and / or the LBT subband. For example, the WTRU can be (e.g., pre-)configured with a range of resource sizes for performing LBT and / or transmissions based on the CBR of the resource pool and / or the LBT subband. The WTRU can (e.g., then) determine which resource size to select for performing LBT and / or transmissions based on the measured CBR of the resource pool and / or the LBT subband. For example, if the CBR of the resource pool and / or the LBT subband is greater than a threshold, the WTRU can use a smaller resource size. If the CBR of the resource pool and / or the LBT subband is less than a threshold, the WTRU can use a larger resource size.

[0107] In the fourth example, the WTRU can determine the resource size based on any of the QoS of the TB, SLRB, and LCH. For example, the WTRU can be (e.g., pre-)configured with a range of resource sizes for performing LBT and / or transmissions based on the QoS of the TB (e.g., the priority of the TB). The WTRU can then determine which resource size to use to perform the LBT and / or transmission based on the QoS associated with the TB.

[0108] In the fifth example, the WTRU can determine the resource size based on one or more LBT parameters used for accessing the channel. In one example, the WTRU can determine the resource size for performing LBT and / or transmission based on the LBT type for multi-channel access. For example, the WTRU can be (e.g., pre-)configured with a range of resource sizes for a minimum of M LBT subbands spanning N time slots for each LBT type for multi-channel access. For example, the WTRU can be (e.g., pre-configured) with a resource size of one LBT subband spanning one time slot for LBT type A. Alternatively, the WTRU can be (e.g., pre-configured) with a resource size of two LBT subbands spanning two time slots for LBT type B. In another example, the WTRU can determine the resource size to be used to perform LBT and / or transmission based on the CAPC of the TB. For example, the WTRU can be (e.g., pre-configured) with a range of resource sizes for performing LBT and / or transmission based on the CAPC of the TB. The WTRU can then determine which resource size to use for LBT and / or transfer based on the TB's CAPC and the (e.g., pre-)configured range of resource sizes. For example, the WTRU can select a small resource size for high CAPC priority (i.e., low CAPC value) and a large resource size for low CAPC priority (e.g., high CAPC value). This scheme allows low-CPAC data to access more resources based on a longer LBT time. In yet another example, the WTRU can determine the resource size based on the current contention window (TB). CW p The resource size to be used to perform LBT and / or transfer is determined by the contention window and / or backoff value N. The WTRU can be (e.g., pre-)configured with a range of resource sizes for each contention window and / or backoff value. The WTRU can then be configured based on the contention window ( CW p The resource size is determined by the fallback value N and / or the rollback value N.

[0109] In the sixth example, the WTRU can determine the resource size based on the WTRU's buffer state (e.g., the amount of data in the buffer and / or the amount of data in the (e.g., pre-)configured set of logical channels (LCHs). In one example, for each range of the total amount of data in the buffer, the WTRU can be (e.g., pre-)configured with at most / at least M LBT subbands and / or at most / at least N time slots for LBT. The WTRU can then determine which value of M and / or N to use based on the amount of data in the buffer. For example, if the WTRU has less than a first (e.g., pre-)configured threshold of total data in the buffer, the WTRU can use a resource size of one RB set and one time slot. For example, if the total amount of data is greater than the first threshold and less than the second threshold, the WTRU can use a resource size of two RB sets and one time slot or one RB set and two time slots. For example, if the total amount of data is greater than a third threshold, the WTRU can use a resource size of two RB sets and two time slots or three RB sets and one time slot. In yet another example, WTRU can determine the resource size (e.g., the maximum value of M and / or N) based on the priority of the data volume being greater than (e.g., pre-)configured thresholds.

[0110] WTRU performs LBT and / or transmission schemes in a TB broadband operation. In some embodiments, the WTRU may perform one or any combination of the following LBT and / or transmission schemes in a broadband operation for one TB.

[0111] In the first scenario, the WTRU can initially select an LBT subband. The WTRU can perform LBT and / or TB transmissions within the selected LBT subband. The WTRU can perform (e.g., all) TB transmissions (e.g., initial transmission and (one or more) retransmissions) within the same LBT subband.

[0112] In the second scheme, the WTRU can perform LBT and / or TB transmissions across multiple LBT subbands. For example, the WTRU can select one LBT subband to perform LBT and / or transmissions for each (e.g.,) TB. The WTRU can select resources for LBT and / or transmissions such that two resources in two LBT subbands do not overlap.

[0113] In the third scheme, the WTRU can execute an LBT type (e.g., any one of type A, B, A1, A2, B1, B2) to access multiple LBT subbands. When an LBT is successful, the WTRU can perform a transmission in (e.g., each) subband. If the WTRU acquires multiple LBT subbands in a time slot, it can perform multiple transmissions of the TB (e.g., an initial transmission and one or more retransmissions) in the same time slot, where each outgoing transmission can be associated with an LBT subband. The WTRU can indicate (e.g., in the sidechain control information (SCI)) that it can perform multiple transmissions of the TB in the same time slot. The WTRU can indicate information related to the transmissions in the same time slot, which can implicitly or explicitly include the set of LBT subbands. This scheme can assist the Rx WTRU in TB decoding.

[0114] In the fourth scheme, the WTRU can execute an LBT type (e.g., any of type A, B, A1, A2, B1, B2) to access multiple LBT subbands. If the WTRU acquires multiple LBT subbands in a time slot, it can execute a transmission across a TB spanning the acquired LBT subbands. The WTRU can acquire adjacent LBT subbands to execute such a transmission. If the WTRU acquires non-adjacent LBT subbands, it can execute a transmission within a subset of the acquired LBT subbands, which can be adjacent subbands. The WTRU can indicate (e.g., in an SCI) the set of subbands used for a transmission of the TB. The WTRU can transmit an SCI within one of the LBT subbands (e.g., the lowest / highest index LBT subband).

[0115] exist Figure 3 In one example shown, the WTRU can execute one of the four LBT and / or transmission schemes discussed above for a TB. For example, the WTRU can be configured with two LBT subbands (e.g., LBT subbands 1 and 2) to perform broadband operation. Figure 3 In the first LBT and / or transmission scheme shown at point 31, the WTRU may first select an LBT subband (e.g., LBT subband 1) to perform the LBT and / or transmission. The WTRU may then select resources for performing the LBT and potential transmission.

[0116] exist Figure 3 In the second LBT and / or transmission scheme shown at point 32, the WTRU can select each resource for the LBT and / or transmission. The WTRU can then perform two initial transmissions in the first LBT subband. The WTRU can then perform the final transmission of the TB in the second LBT subband.

[0117] exist Figure 3In the third LBT and / or transmission scheme shown at point 33, the WTRU can perform an LBT and acquire two LBT subbands, for example, simultaneously. The WTRU can then perform a TB transmission across the two LBT subbands. In each time slot, the WTRU can perform two transmissions, each of which can be within one LBT subband.

[0118] Unlike the third scheme, in the fourth scheme shown at 34, the WTRU can perform one transmission of the TB across two LBT subbands in each time slot. Guard bands can be used in both the third and fourth schemes shown at 33 and 34.

[0119] WTRU performs LBT and / or transport schemes in multi-terabyte broadband operations. The WTRU can perform one or any combination of the following LBT and / or transport schemes in broadband operations targeting multiple TBs: In the first scheme (e.g., which may be referred to as Scheme A), the WTRU can execute an LBT type (e.g., type A, B, A1, A2, B1, B2) to access multiple LBT subbands. The WTRU can execute a transmission for each TB within the acquired set of LBT subbands. The WTRU can execute one or more transmissions of a TB, where each (e.g., every) transmission of a TB can be within an LBT subband. The WTRU can execute one transmission of a TB (e.g., an initial transmission) within one LBT subband and one or more other transmissions of the TB (e.g., retransmissions) in other LBT subbands. Each transmission of a TB can occupy one time slot. The WTRU can execute the transmission of a TB within one or more time slots.

[0120] In the second scheme (e.g., which may be referred to as Scheme B), the WTRU can perform an LBT type (e.g., type A, B, A1, A2, B1, B2) to access multiple LBT subbands. The WTRU can perform (e.g., each) TB transmissions in the set of acquired LBT subbands. The WTRU can perform one or more TB transmissions in multiple LBT subbands, where each transmission can span multiple LBT subbands (e.g., span multiple (e.g., all) acquired LBT subbands).

[0121] In the third scheme (e.g., which may be referred to as scheme C), the WTRU may combine the first and second schemes, wherein the WTRU may use the first scheme for one set of TBs (e.g., the first one or more TBs transmitted in the COT) and may use the second scheme for another set of TBs (e.g., the last one or more TBs transmitted in the COT).

[0122] In the fourth scheme (e.g., which may be referred to as Scheme D), the WTRU can select LBT subbands to perform LBT and / or transmissions for each TB. The WTRU can use the same or different LBT subbands for multiple TBs. The WTRU can execute an LBT type (e.g., type A, B, A1, A2, B1, B2) to access multiple LBT subbands. If an LBT is successful in an LBT subband, the WTRU can perform transmissions for the associated TB within that LBT subband.

[0123] exist Figure 4 In one example shown, the WTRU can execute one of four LBT and / or transport schemes for multiple TBs. For example, in Figure 4 In the first LBT and / or transmission scheme shown at point 41, the WTRU can perform LBT and acquire two LBT subbands within the same time slot. The WTRU can perform multiple transmissions of a TB within one time slot, where each transmission can be within one LBT subband. For example... Figure 4 As shown, the WTRU can perform two TBs of transmissions, where the first TB of transmissions is within the diagonally shaded rectangle shown at 401 and the second TB of transmissions is within the horizontally shaded rectangle shown at 402. The WTRU can perform four transmissions per TB across two time slots. Within each time slot, the WTRU can perform two transmissions per TB, where each transmission can be within one LBT subband.

[0124] exist Figure 4 In the second LBT and / or transmission scheme shown at point 42, the WTRU can perform one transmission of one TB in each time slot, which can span multiple acquired LBT subbands.

[0125] exist Figure 4 In the third LBT and / or transmission scheme shown at point 43, the WTRU may use the first scheme for the first TB and the second scheme for the second TB.

[0126] exist Figure 4 In the fourth scheme shown at point 44, the WTRU can select the first and second LBT subbands for the first and second TBs respectively. The WTRU can then independently perform LBT and / or transmission for each TB in each LBT subband.

[0127] The WTRU directs its LBT and / or transmission scheme to another network element. The WTRU may indicate its LBT and / or transmission scheme (e.g., transmit information indicating its LBT and / or transmission scheme) to other network elements (e.g., one or more receiver WTRUs). The WTRU may use one or any combination of NAS, PCT Radio Resource Control (RRC), MAC Control Element (MAC CE), and / or SCI to indicate its LBT and / or transmission scheme. In one example, the WTRU may use one or more SCIs (e.g., a second-stage SCI) associated with one or more transmissions of a TB to indicate whether the TB spans multiple subbands or is within a single LBT subband. The WTRU may use an SCI to indicate whether it performs multiple transmissions of the TB in a time slot. The WTRU may also use an SCI to indicate a set of LBT subbands used for simultaneous transmissions of the TB in the same time slot.

[0128] WTRU determines which LBT and / or transmission scheme should be used for broadband operation. In some embodiments, the WTRU may determine which LBT and / or transport scheme should be used for broadband operation based on one or any combination of the following ten examples.

[0129] In the first example, the WTRU can determine which LBT and / or transmission scheme should be used for broadband operation based on (e.g., pre-)configuration in a resource pool. For example, the WTRU can be configured with resource pool information indicating whether a TB transmission should be performed in one or more LBT subbands. For example, the WTRU can be (e.g., pre-)configured with one or more LBT types (e.g., any one of types A, B, A1, A2, B1, B2) for multi-channel access. The WTRU can then use one of the (e.g., pre-)configured LBT types to access multiple channels.

[0130] In the second example, the WTRU can determine which LBT and / or transmission scheme to use for broadband operation based on whether a guard band is configured (e.g., pre-configured) in the resource pool. In one example, for a TB transmission, the WTRU can determine the LBT scheme based on whether a guard band is configured (e.g., pre-configured) in the resource pool. For example, if a guard band is not configured (e.g., pre-configured) in the resource pool, the WTRU can determine to perform one type of LBT procedure for multi-channel access (e.g., any of LBT types A2, B, B1, B2, where the LBT procedure in one LBT subband depends on the LBT procedure in another LBT subband). Otherwise, if a guard band is configured (e.g., pre-configured) in the resource pool, the WTRU can perform any type of LBT for multi-channel access (e.g., LBT type A1). In another example, the WTRU can determine the transmission scheme based on whether a guard band is configured (e.g., pre-configured) in the resource pool. For example, if a guard band is not configured (e.g., pre-configured) in the resource pool, the WTRU can perform a TB transmission across multiple LBT subbands. Otherwise, if a guard band is pre-configured in the resource pool, the WTRU can perform multiple TB transmissions in the same time slot, where each transmission can be within an LBT subband.

[0131] In the third example, the WTRU can determine which LBT and / or transmission scheme should be used for wideband operation based on the acquired set of LBT subbands. For example, if the WTRU acquires a set of adjacent LBT subbands, it can select an LBT and / or transmission scheme (e.g., Figure 3 The diagram illustrates a fourth LBT and / or transmission scheme for a TB, where each transmission can be within an LBT subband. For example, if the WTRU acquires a non-adjacent LBT subband, the WTRU can use another LBT and / or transmission scheme (e.g., Figure 3 The third LBT and / or transmission scheme shown is for one TB, where each transmission can span multiple LBT subbands.

[0132] In the fourth example, the WTRU can determine which LBT and / or transport scheme should be used for broadband operation based on the QoS associated with any of the TB, SLRB, and LCH. For example, if the reliability of the TB is greater than a threshold, the WTRU can select an LBT and / or transport scheme (e.g., such as...). Figure 3 The first LBT and / or transmission scheme shown is for a TB. Otherwise, if the reliability of the TB is less than a threshold, the WTRU can choose another LBT and / or transmission scheme (e.g., Figure 3 The second LBT and / or transmission scheme for one TB is shown in the figure.

[0133] In the fifth example, the WTRU can determine which LBT and / or transmission scheme should be used for broadband operation based on the size of the TB. For example, if the size of the TB is less than a threshold, the WTRU can select an LBT and / or transmission scheme for a single TB (e.g., Figure 3 The first or second LBT and / or transmission scheme shown is for a TB; otherwise, if the size of the TB is greater than the threshold, the WTRU can choose another LBT and / or transmission scheme (e.g., Figure 3 The diagram illustrates a third or fourth LBT and / or transmission scheme for a TB, where the WTRU can perform simultaneous transmission of the TB across multiple LBT subbands. The TB size threshold can be configured (e.g., pre-configured) in the resource pool.

[0134] In the sixth example, the WTRU can determine which LBT and / or transmission scheme should be used for wideband operation based on the WTRU's buffer state. For example, if the WTRU's buffer size is less than a threshold, the WTRU can select an LBT and / or transmission scheme (e.g., such as...). Figure 4 The diagram illustrates LBT and / or transmission scheme D for multiple TBs, where the WTRU can select an LBT subband for each TB. Otherwise, if the WTRU's buffer size is greater than a threshold, the WTRU can select another LBT and / or transmission scheme (e.g., as shown in the diagram). Figure 4 The LBT and / or transmission scheme C shown is for multiple TBs, where the WTRU can transmit a TB across multiple LBT subbands. The buffer size threshold can be configured (e.g., pre-configured) in the resource pool.

[0135] In the seventh example, the WTRU can determine which LBT and / or transport scheme should be used for broadband operation based on the data rate associated with the service (e.g., requirements). For example, if the data rate associated with the sidechain service (e.g., requirements) is less than a threshold, the WTRU can select an LBT and / or transport scheme (e.g., such as...). Figure 4 The diagram illustrates LBT and / or transmission scheme D for multiple TBs, where the WTRU can select an LBT subband for each TB. Otherwise, if the WTRU's data rate exceeds a threshold, the WTRU can select another LBT and / or transmission scheme (e.g., as shown in the diagram). Figure 4 The LBT and / or transmission scheme C shown can be used where the WTRU can transmit a TB across multiple LBT subbands. The buffer size threshold can be configured (e.g., pre-configured) in the resource pool.

[0136] In the eighth example, the WTRU can determine which LBT and / or transmission scheme should be used for broadband operation based on the resource pool and / or the CBR of the LBT subband. For example, if the CBR is greater than a threshold, the WTRU can select an LBT and / or transmission scheme (e.g., such as...). Figure 3 The first LBT and / or transmission scheme shown is for one TB. Otherwise, if the CBR is less than the threshold, the WTRU can choose another LBT and / or transmission scheme (e.g., as shown). Figure 3 The second LBT and / or transmission scheme for one TB is shown in the figure.

[0137] In the ninth example, the WTRU can determine which LBT and / or transmission scheme should be used for broadband operation based on the transmission order of TBs in the COT and / or the transmission time slots of the COT. For example, for one or more TBs at the beginning of the COT, the WTRU can select an LBT and / or transmission scheme for one TB (e.g., such as...). Figure 3 The diagram illustrates a first LBT and / or transmission scheme for a TB, where the WTRU can perform multiple transmissions of the TB within a time slot, and each transmission can be within an LBT subband. For example, for one or more TBs at the end of a COT, or for TBs preceding or following one or more TBs of the COT, the WTRU can select a different LBT and / or transmission scheme for another TB (e.g., as shown). Figure 3 The second LBT and / or transmission scheme shown here, in which the WTRU can perform a TB transmission in a time slot across multiple LBT subbands.

[0138] In the tenth example, the WTRU can determine which LBT and / or transmission scheme should be used for broadband operation based on the number of TBs prepared for LBT and / or transmission. For example, if the WTRU has prepared one TB before the LBT, it can execute one LBT and / or transmission scheme (e.g., as...). Figure 3 The first LBT and / or transmission scheme is shown. Otherwise, if the WTRU has prepared more than one TB (e.g., two TB) before the LBT, it can execute another LBT and / or transmission scheme (e.g., as shown). Figure 3 The fourth LBT and / or transmission scheme shown.

[0139] WTRU determines the number of TBs to be prepared for LBTs and / or transmissions in broadband operations. In one approach, the WTRU may prepare only one TB for one or more LBTs and / or transmission opportunities within a set of LBT subbands. In another approach, the WTRU may prepare multiple TBs for one or more LBTs and / or transmission opportunities. The WTRU may determine the number of TBs to be prepared for one or more LBTs and / or transmission opportunities based on any of the following: (i) the resource size for performing the LBTs and / or transmissions; and (ii) the set of LBT subbands for performing the LBTs and / or transmissions.

[0140] For example, WTRU can determine a number of TBs that are smaller in terms of resource size than the number of LBT subbands for LBT and / or transmission.

[0141] For example, the WTRU can be (e.g., pre-)configured with a maximum / minimum number of TBs to be prepared based on the number of LBT subbands that the WTRU may intend to use to perform LBT and / or transmission. The WTRU can then determine the number of TBs to be prepared to meet the maximum / minimum (e.g., pre-)configured value.

[0142] For example, the WTRU can perform a transmission for each TB within an LBT subband. The WTRU can then determine the number of TBs to be prepared for broadband operation based on the number of LBT subbands that the WTRU intends to use to perform LBTs and / or transmissions. The WTRU can then determine the number of TBs used to perform transmissions based on the number of acquired LBT subbands. For example, the WTRU can perform a transmission for each TB within an acquired LBT subband.

[0143] The WTRU determines which TB to transmit from the acquired set of LBT subbands. In some embodiments, the WTRU can prepare multiple TBs for broadband operation. The WTRU can perform LBT within a set of LBT subbands. The WTRU can acquire one or more LBT subbands. The WTRU can determine which TB to transmit in one or more acquired resources of one or more LBT subbands based on one or any combination of the following four examples.

[0144] In the first example, the WTRU can determine which TB to transmit in one or more acquired resources within one or more LBT subbands based on the LBT subband associated with the initial transmission of the TB. For example, the WTRU can determine which TB can be transmitted in an LBT subband based on whether the LBT subband is used for the initial transmission of the TB. For example, for a COT acquired in an LBT subband, the WTRU can prioritize the TB with the initial transmission in the LBT subband.

[0145] In the second example, the WTRU can determine which TB to transmit in one or more acquired resources across one or more LBT subbands based on the QoS associated with the TB. For example, if the number of acquired LBT subbands is less than the number of acquired LBT subbands, the WTRU can select which TB to transmit based on the QoS of the TB. Specifically, the WTRU can prioritize TBs with higher priority for transmission first. In another example, the WTRU can determine which TB to transmit based on whether it is an initial transmission or a retransmission of the TB. Specifically, the WTRU can prioritize retransmissions of the TB relative to the initial transmission of the TB within the acquired LBT subbands.

[0146] In the third example, the WTRU can determine which TB to transmit in one or more acquired resources of one or more LBT subbands based on the remaining PDB of the TB. For example, the WTRU can determine whether to perform the initial transmission of the TB or the retransmission of another TB. In one scenario, the WTRU can prioritize TBs used for retransmission. In another scenario, the WTRU can determine which TB to transmit in the resources based on the remaining PDB of the TB. For example, the WTRU can prioritize TBs with smaller remaining PDBs. If the remaining PDB of the TB used for retransmission is less than the PDB of the TB used for initial transmission, the WTRU can prioritize the TB for retransmission. Otherwise, the WTRU can prioritize the TB for initial transmission.

[0147] In the fourth example, the WTRU can determine which TB to transmit in one or more acquired resources of one or more LBT subbands based on one or more LBT parameters associated with the TB. In one example, the WTRU can determine whether a TB can be transmitted in an acquired COT of an LBT subband based on one or more LBT parameters used for accessing the LBT subband. Specifically, the WTRU can be (e.g., pre-)configured with one or more LBT parameters for accessing the channel based on the TB's QoS. Based on the values ​​of the one or more LBT parameters used for accessing the channel, the WTRU can determine which TB can access the channel (e.g., a TB with a priority greater than a threshold). Then, if the TB's QoS (e.g., priority) is greater than the threshold, the WTRU can perform the TB transmission in the acquired COT. Otherwise, the WTRU can not transmit the TB in the acquired COT. In another example, the WTRU can determine which TB to transmit in the acquired LBT based on the CAPC associated with the TB. Specifically, the WTRU can prioritize TBs with the lowest CAPC value (e.g., the highest priority).

[0148] WTRU determines whether to perform LBT subband selection (reselection). In some embodiments, the WTRU can perform transmissions within a set of LBT subbands. The WTRU can trigger LBT subband selection (reselection). For example, the WTRU can determine which LBT subbands to select or reselect for its transmissions. For LBT subband selection, the WTRU can select a set of LBT subbands for performing LBTs and / or transmissions. For LBT subband reselection, the WTRU can reselect different or the same set of LBT subbands. The WTRU can select (reselect) a primary LBT subband for performing a type of LBT (e.g., type 1 LBT) for a type of multi-channel LBT (e.g., type BLBT). LBT subband selection (reselection) can be triggered based on one or any combination of the following nine examples of events (e.g., based on any of the following conditions being met).

[0149] In the first example, LBT subband selection (reselection) can be triggered based on the number of available resources (e.g., time slots) within a window (e.g., a resource selection window) being less than a threshold. For example, the WTRU can be (e.g., pre-)configured with a threshold for the number / percentage of available resources (e.g., available time slots) used to trigger LBT subband selection (reselection). The WTRU can first determine the set of available resources (e.g., time slots) within the window (e.g., a resource selection window). If the percentage / number of available resources is less than (e.g., pre-)configured, the WTRU can trigger subband selection (reselection). Otherwise, the WTRU can use the current LBT subband.

[0150] In the second example, LBT subband selection (reselection) can be triggered based on the preemption of one or more reserved resources in the current set of LBT subbands. For example, if one or more of the reserved resources of the WTRU are preempted, the WTRU can trigger LBT subband selection (reselection).

[0151] In the third example, LBT subband selection (reselection) can be triggered based on WTRU triggering resource selection (reselection). For example, if WTRU triggers resource selection (reselection), then WTRU can trigger LBT subband selection (reselection).

[0152] In the fourth example, LBT subband selection (reselection) can be triggered based on the WTRU's failure to access the channel after multiple LBT attempts. For example, the WTRU can select a certain number of resources (e.g., time slots) to perform LBT before transmission. If the number of LBT failures exceeds a threshold, the WTRU can trigger LBT subband switching. The threshold can be configured in a resource pool (e.g., pre-configured) and can be a function of the TB's QoS, one or more LBT parameters, and the resource pool's CBR.

[0153] In the fifth example, LBT subband selection (reselection) can be triggered based on the WTRU's failure to access the channel after a certain period. For example, the WTRU can perform LBT for accessing the channel for one or more TBs of transmission. If the WTRU fails to access the channel after (e.g., a pre)configured period, the WTRU can trigger LBT subband selection (reselection). (e.g., the pre)configured period can be a function of the TB's QoS, one or more LBT parameters (e.g., CAPC, contention window, etc.), and the resource pool and / or the CBR of the LBT subband.

[0154] In the sixth example, LBT subband selection (reselection) can be triggered based on the number of transmissions for one or more TBs within a certain time period being less than a threshold. For example, if the number of transmissions performed for one or more TBs within a time period threshold is less than the threshold, the WTRU can trigger LBT subband selection (reselection). The number of transmission thresholds and / or time period thresholds can be configured in the resource pool (e.g., pre-configured) and can be a function of any of the TB's QoS, one or more LBT parameters, and the resource pool's CBR.

[0155] In the seventh example, LBT subband selection (reselection) can be triggered based on the WTRU's failure to transmit one or more TBs. For example, if the WTRU fails to transmit (e.g., a certain) number of TBs, the WTRU can trigger LBT subband reselection. The number of failed TB transmissions used to trigger LBT subband selection (reselection) can be (e.g., pre) configured in a resource pool, which can depend on any of the TB's QoS, the resource pool's CBR, and one or more LBT parameters used for accessing the channel. The WTRU can consider whether a TB transmission has failed based on any of the following: (i) the number of transmissions for the TB (e.g., within the TB's PDB) is less than a threshold (which can be a function of the TB's QoS); and (ii) the WTRU does not receive any ACK feedback from the Rx WTRU within the TB's PDB to acknowledge the reception of the TB, or the WTRU receives a NACK feedback from the Rx WTRU to indicate reception failure.

[0156] In the eighth example, LBT subband selection (reselection) can be triggered based on one or more LBT parameters satisfying (e.g., pre-configured) conditions for LBT subband selection (reselection). For example, if the WTRU uses the maximum contention window value for (e.g., pre-)configured time period, (e.g., pre-)configured number of times, and (e.g., pre-)configured COT number. CW p = CW maxThen WTRU can be (e.g., pre-)configured to perform LBT subband selection (reselection).

[0157] In the ninth example, LBT subband selection (reselection) can be triggered based on the CBR of one or more LBT subbands in the current set of LBT subbands being greater than a threshold. For example, if the CBR of the current LBT subband of the WTRU is greater than the threshold, the WTRU can trigger LBT subband selection (reselection). The threshold can be configured in the resource pool (e.g., pre-configured).

[0158] WTRU determines the set of LBT subbands used to perform LBT and / or transmission. In some embodiments, the WTRU can perform LBT subband selection (reselection) by performing one or any combination of the following two examples of operations.

[0159] In the first example of operation, the WTRU may select an LBT subband or a set of LBT subbands (one or more) for performing one or more TBs of LBT and / or transmission.

[0160] In the second example of operation, for multi-channel access, the WTRU can determine the LBT subband (i.e., the primary LBT subband) for performing one type of LBT (e.g., type 1 LBT). If the LBT is successful in the selected LBT subband, the WTRU can determine the set of LBT subbands to select for performing another type of LBT (e.g., the WTRU can target at least...). T mc = 25 μs The WTRU can then determine the set of LBT subbands to perform the transmission from the set of successful LBT subbands.

[0161] WTRU can determine the set of (one or more) LBT subbands for performing LBT and / or transmission based on one or any combination of the following ten examples.

[0162] In the first example, the WTRU can determine the set of one or more LBT subbands for performing LBT and / or transmission based on the CBR of the LBT subband. In one example, the WTRU can select an LBT subband with a CBR less than a threshold. Specifically, the WTRU can be (e.g., pre-)configured with a CBR threshold for selecting LBT subbands. If the CBR of an LBT subband is less than the threshold, the WTRU can be allowed to select an LBT subband. Otherwise, the WTRU can not select an LBT subband. If the WTRU has multiple LBT subbands with CBRs below the threshold, in one scenario, the WTRU can select the LBT subband with the lowest CBR. In another scenario, the WTRU can select an LBT subband (e.g., randomly) from the set of LBT subbands that meet the CBR threshold.

[0163] In the second example, the WTRU can determine the set of one or more LBT subbands for performing LBT and / or transmission based on the set of available resources in a window (e.g., a resource selection window). For example, the WTRU can be (e.g., pre-)configured with a threshold for the number / percentage of available resources (e.g., available time slots) for performing LBT and / or transmission in an LBT subband. If the number / percentage of available resources (e.g., time slots) for performing LBT and / or transmission is greater than the threshold, the WTRU can select an LBT subband. Otherwise, the WTRU can not select an LBT subband. If multiple LBT subbands possessed by the WTRU have a number / percentage of available resources less than the threshold, in one scenario, the WTRU can select the LBT subband with the highest number / percentage of available resources. In another scenario, the WTRU can select an LBT subband from the set of LBT subbands that meet the threshold (e.g., randomly).

[0164] In the third example, the WTRU can determine a set of one or more LBT subbands for performing LBT and / or transmission based on the selected primary LBT subband for wideband operation. For example, upon successful LBT in the primary LBT subband, the WTRU can detect when the channel can be idle for at least [time period missing]. T mc = 25 μs The LBT subband for performing the transmission is then selected. The WTRU can select secondary LBT subbands for transmission that satisfy the contiguousness of the primary LBT subband. Specifically, the WTRU can prioritize transmissions in the primary LBT subband and the two LBT subbands adjacent to it. For example, the WTRU can acquire a set of LBT subbands for performing the transmission. If the acquired set of LBT subbands is non-adjacent, the WTRU can discard one or more of the LBT subbands(s), resulting in non-adjacent transmissions with respect to the primary LBT subband.

[0165] In the fourth example, the WTRU can determine the set of (one or more) LBT subbands for performing LBT and / or transport based on the destination associated with the TB. For example, the WTRU can be (e.g., pre-)configured with a set of LBT subbands for (e.g., per) destination (e.g., for each destination ID, each unicast pair, each multicast ID, etc.). The WTRU can then determine the set of LBT subbands for performing LBT and / or transport based on the (e.g., pre-)configured LBT subbands for the destination. The (pre)configuration can be based on the association between LBT subbands and services. The (pre)configuration can be based on negotiation between WTRUs in a group (e.g., for unicast, multicast), where the WTRUs can use PC5 RRC to communicate this negotiation.

[0166] In the fifth example, the WTRU can determine the set of one or more LBT subbands for performing LBT and / or transmissions based on whether HARQ feedback resources are (e.g., pre-)configured in the LBT subbands. For example, for a HARQ-enabled TB, the WTRU can prioritize LBT subbands with (e.g., pre-)configured HARQ feedback resources. For a HARQ-disabled TB, the WTRU can prioritize LBT subbands without (e.g., pre-)configured HARQ feedback resources.

[0167] In the sixth example, the WTRU can determine the set of one or more LBT subbands(s) for performing LBT and / or transmission based on one or more LBT parameters used for accessing each LBT subband. For example, the WTRU can select LBT subbands with a contention window (e.g., a value) less than a threshold. Specifically, the WTRU can be (e.g., pre-)configured with a contention window threshold (e.g., for...) for selecting LBT subbands. CW p , CW min,p or CW max,p The threshold is used to determine the LBT subband contention window (e.g., value). If the contention window of the LBT subband is less than the threshold, the WTRU may be allowed to select an LBT subband. Otherwise, the WTRU may not select an LBT subband. If the WTRU has multiple LBT subbands with contention windows (e.g., values) below the threshold, in one scenario, the WTRU may select the LBT subband with the lowest contention window value. In another scenario, the WTRU may select an LBT subband from the set of LBT subbands that satisfy the contention window threshold (e.g., randomly).

[0168] In the seventh example, the WTRU can determine a set of (one or more) LBT subbands for performing LBT and / or transmission based on (e.g., the earliest available resource for each) LBT subband. For example, the WTRU can prioritize LBT subbands with the earliest available resource (e.g., time slot) for LBT and / or transmission.

[0169] In the eighth example, the WTRU can determine a set of (one or more) LBT subbands for performing the LBT and / or transmission based on the first successful subband in the LBT. For example, the WTRU can perform the LBT in the set of LBT subbands, and the WTRU can then perform the transmission in the first acquired LBT subband.

[0170] In the ninth example, the WTRU can determine the set of one or more LBT subbands for performing LBT and / or transmissions based on the availability of a shareable COT within an LBT subband. For example, the WTRU can prioritize selecting LBT subbands with shareable COTs within a resource selection window. The WTRU can share a COT with another WTRU using frequency division multiplexing (e.g., the WTRU can use orthogonal interleaving with interleaving used by the COT initiator WTRU) or time division multiplexing (e.g., the WTRU can perform a transmission after another WTRU has completed its transmission).

[0171] In the tenth example, the WTRU can determine a set of (one or more) LBT subbands for performing LBT and / or transmissions based on implicit / explicit indications from another network element. Specifically, the WTRU can implicitly / explicitly receive an indication from an RxWTRU to perform LBT and / or transmissions in an LBT subband. The WTRU can then select the LBT subband for performing LBT and / or transmissions. In one example, the WTRU can receive HARQ ACK / NACK feedback from an Rx WTRU. The TxWTRU can then select an LBT subband with HARQ feedback from the Rx WTRU to perform LBT and / or transmissions. In another example, the WTRU can receive an indication from an Rx WTRU (e.g., via a PC5 Radio Resource Control (RRC) message) to perform LBT and / or transmissions in an LBT subband. The WTRU can then perform LBT and / or transmissions in the indicated LBT subband. In yet another example, the WTRU can receive a transmission from a peer WTRU in an LBT subband. The WTRU can then select the LBT subband to perform LBT and / or transmission. In another example, the WTRU can receive sensing information (e.g., a set of available resources) in an LBT subband. The WTRU can then select the LBT subband with the sensing information to perform LBT and / or transmission.

[0172] WTRU determines whether to maintain the current set of (one or more) LBT subbands to perform LBT and / or transmission. In some embodiments, the WTRU may semi-statically use a set of LBT subbands to perform LBT and / or transmissions. The WTRU may trigger resource allocation (e.g., for either a new TB or a retransmission of an existing TB). The WTRU may determine whether to maintain the current set of LBT subbands(s) to perform LBT and / or transmissions based on one or any combination of the following five examples.

[0173] In the first example, the WTRU can determine whether to maintain the current set of one or more LBT subbands to perform LBT and / or transmission based on the resource pool and / or the CBR of the LBT subband. For example, if the CBR of the LBT subband is less than a threshold, the WTRU can determine to maintain the current LBT subband. Otherwise, the WTRU can switch to another LBT subband to perform LBT and / or transmission.

[0174] In the second example, the WTRU can determine whether to maintain the current set of LBT subbands (one or more) to perform LBT and / or transmission based on the availability of shareable COTs in the current set of LBT subbands. For example, if the WTRU detects shareable COTs in the current set of LBT subbands (one or more), the WTRU can maintain the current set of LBT subbands.

[0175] In the third example, the WTRU can determine whether to maintain the current set of LBT subbands(one or more) for LBT and / or transmission based on the availability of a shareable COT in another set of LBT subbands. For example, if the WTRU detects a shareable COT in another set of LBT subbands within a resource selection window, the WTRU can switch to another LBT subband.

[0176] In the fourth example, the WTRU can determine whether to maintain the current set of LBT subbands(one or more) to perform LBT and / or transmission based on one or more LBT parameters satisfying (e.g., pre)configuration conditions for maintaining LBT subbands(one or more). In one example, the WTRU can be (e.g., pre)configured with a contention window threshold for maintaining the current set of LBT subbands(one or more) (e.g., CW p , CW min,p or CW max,p The threshold). If the competing window (e.g., value) meets (e.g., pre)configured threshold (e.g., ... CW p Less than CW pIf the threshold is less than the specified value, the WTRU can maintain the current set of LBT subbands. Otherwise, the WTRU can switch to another set of LBT subbands(one or more). In another example, the WTRU can be (e.g., pre-)configured with an initialized backoff value threshold for maintaining the current set of LBT subbands(one or more). If the initialized backoff value is less than the threshold, the WTRU can maintain the current set of LBT subbands. Otherwise, the WTRU can switch to another set of LBT subbands(one or more).

[0177] In the fifth example, the WTRU can determine whether to maintain the current set of LBT subbands for performing LBT and / or transmission based on the number of available resources (e.g., time slots) in a window (e.g., a resource selection window). For example, the WTRU can be (e.g., pre-)configured with a threshold of the number / percentage of available resources (e.g., available time slots) for performing LBT and / or transmission to maintain the current set of LBT subbands. If the number / percentage of available resources (e.g., time slots) is greater than the threshold, the WTRU can maintain the current set of LBT subbands. Otherwise, the WTRU can select a different set of LBT subbands.

[0178] WTRU determines the available resources (e.g., time slots) for LBT and / or transmissions. In some embodiments, the WTRU may determine a set of available resources (e.g., time slots) in a resource selection window for performing LBT and / or transmission. Specifically, the WTRU may determine a resource as available if it satisfies one or any combination of the following two examples of conditions.

[0179] In the first example, if a resource (e.g., a time slot) is not reserved by any WTRU, the WTRU can determine that the resource is available.

[0180] In the second example, if a resource (e.g., a time slot) is reserved by another WTRU and the sidechain reference signal received power (SL-RSRP) is less than a threshold, the WTRU can determine that the resource is available. In one scenario, the threshold can be fixed and can be a function of the channel idle detection threshold. In another scenario, the threshold can be based on any of the following: (i) one or more LBT parameters of the reservation WTRU used to reserve the channel; (ii) the QoS of the reservation TB; (iii) one or more LBT parameters of the WTRU used to access the channel; and (iv) the QoS of the TB and / or SLRB / LCH.

[0181] WTRU determines which time slot should perform one or more TB of LBT and / or transmission. In some embodiments, the WTRU (e.g., firstly) can determine a set of available resources (e.g., time slots) based on SCI decoding in a resource selection window. The resource selection window can be a window that begins after a first offset (e.g., T1) from a time slot (e.g., n) in which the WTRU may have triggered resource selection and ends after a second offset (e.g., T2) from a time slot in which the WTRU may have triggered resource selection (e.g., a window of time slots referred to as [n+T1, n+T2]). The WTRU (e.g., then) can perform one or any combination of the following to select resources (e.g., time slots) for performing LBT and / or transmission.

[0182] In the first scheme, the WTRU can select from a resource selection window a set of the first (e.g., initial) N resources (e.g., time slots) for possible LBT and / or transmission (N may be referred to as an integer). The first (e.g., initial) N resources (e.g., time slots) may be located at the beginning of the resource selection window. In one scheme, the WTRU can select N resources from one LBT subband. In another scheme, the WTRU can select N resources from multiple LBT subbands. The WTRU can select one resource (e.g., a time slot) from the set of the first N resources (e.g., randomly) for performing LBT and / or transmission. If the WTRU successfully acquires the channel, the WTRU can perform the transmission on the selected resource. Otherwise, if the WTRU fails to acquire the channel, in one scheme, the WTRU can select another resource (e.g., a time slot) from the remaining resources of the N resources (e.g., randomly). In another scheme, the WTRU can perform LBT on the next available resource (e.g., a time slot). The value of N (e.g., any one of minimum, maximum, and exact values) can be configured in the resource pool (e.g., pre-configured) and / or can be a function of the QoS of the TB (e.g., any one of priority and remaining PDB), one or more LBT parameters (e.g., contention window), and the CBR of the resource pool.

[0183] In the second scenario, the WTRU can select a window (e.g., a resource selection sub-window) which may be located at the beginning of the resource selection window. The WTRU can then select a resource (e.g., a time slot) within the resource selection sub-window from (e.g., randomly) the set of available resources for performing LBT and / or transmission. If the WTRU successfully acquires a channel, it can perform transmission on the selected resource. Otherwise, if the WTRU fails to acquire a channel, in one scenario, the WTRU can select another resource (e.g., a time slot) from the resource allocation sub-window (e.g., randomly). In another scenario, the WTRU can perform LBT on the next available resource (e.g., a time slot). The size of the resource selection sub-window (e.g., any of minimum size, maximum size, or exact size) can be configured in the resource pool (e.g., pre-configured), and / or can be a function of the QoS of the TB (e.g., priority or remaining PDB), one or more LBT parameters, and the CBR of the resource pool.

[0184] In the first and second schemes above, the WTRU can (e.g., randomly) select resources (e.g., time slots) for performing LBT and / or transmission to reduce conflicts between different WTRUs performing LBT simultaneously.

[0185] exist Figure 5 In one example shown, the WTRU can perform one of two options (e.g., first scheme 51 versus second scheme 52) to determine the first timeslot for LBT and / or transmission. In the first scheme 51, the WTRU can select from the first N=4 available timeslots 511, 512, 513, 514. The WTRU can then select one timeslot from these N=4 available timeslots (e.g., randomly). Figure 5 In the second scenario, the WTRU can determine a resource allocation (RA) subwindow 520 to identify the first time slot in which to perform LBT and / or transmission. Within subwindow 520, the WTRU can have three available time slots 521, 522, and 523. The WTRU can then (e.g., randomly) select one of those three time slots (e.g., ...). Figure 5 The third time slot (523) is used to perform LBT and / or transmission.

[0186] WTRU determines to perform adjacent LBT In some embodiments, the WTRU may perform adjacent LBTs until it acquires an LBT subband for performing the transmission. The WTRU may first select the first resource (e.g., a time slot) for performing the LBT, which may be determined based on one or any combination of the following three schemes.

[0187] In the first scenario, the WTRU can perform SCI decoding to determine the set of available resources. The WTRU can then select a resource (e.g., randomly) from the set of the top N available resources (e.g., time slots), or it can select an available resource (e.g., time slot) from the set of N available resources (e.g., randomly). The WTRU can then perform adjacency LBT until it acquires an LBT subband. The value of N (e.g., any of the minimum (e.g., lower) value, maximum (e.g., upper) value, or exact value) can be (e.g., pre)configured in the resource pool, which can be a function of any of the QoS of the TB (e.g., priority and / or remaining PDB), one or more LBT parameters (e.g., contention window), and the CBR of the resource pool.

[0188] In the second scenario, the WTRU can perform SCI decoding to determine the set of available resources. The WTRU can then select a resource (e.g., a time slot) from the set of available resources within a sub-window (e.g., randomly). The WTRU can then perform adjacency LBT until it acquires an LBT subband. The size of the sub-window (e.g., any of the minimum (e.g., lower) size, maximum (e.g., upper) size, or exact size) can be (e.g., pre-configured) in the resource pool, and can be a function of the QoS of the TB (e.g., priority and / or remaining PDB), one or more LBT parameters, and the CBR of the resource pool.

[0189] In the third scheme, the WTRU may not perform SCI decoding to determine available resources in the resource selection window. The WTRU can first select a resource (e.g., a time slot) in a sub-window (e.g., an RA sub-window) (e.g., randomly) to perform LBT and / or transmission. The WTRU can then perform adjacent LBT until it acquires an LBT subband. The size of the sub-window (e.g., any of the minimum (e.g., lower) size, maximum (e.g., upper) size, or exact size) can be (e.g., pre-configured) in the resource pool, and can be a function of the QoS of the TB (e.g., priority and / or remaining PDB), one or more LBT parameters, and the CBR of the resource pool.

[0190] In the above scheme, the WTRU can select resources (e.g., time slots) for performing LBT and / or transmission to reduce conflicts between different WTRUs performing LBT simultaneously.

[0191] exist Figure 6In one example shown, the WTRU can execute one of three schemes 61, 62, and 63 to determine the first time slot for performing LBT and / or transmission. After the first time slot can be selected, the WTRU can perform adjacency sensing until it acquires the LBT subband. The WTRU can perform SCI decoding in schemes 61 and 62 to determine the set of available resources. Figure 6 In the first scheme 61 illustrated in the top part, the WTRU can select a time slot from the set of the first N available time slots (e.g., randomly). Figure 6 The second time slot is shown at position 612 in the image. Figure 6 In the second scheme 62 illustrated in the middle section, the WTRU can select a time slot from the set of available time slots in the sub-window (e.g., randomly). Figure 6 The third time slot is shown at position 623 in the image. Figure 6 In the third scheme 63 illustrated in the bottom part, the WTRU may not perform SCI decoding to determine the set of available resources. The WTRU may select a time slot in a sub-window (e.g., randomly). Figure 6 The third time slot (shown at position 633 in the text) is used to perform LBT.

[0192] WTRU determines the availability of a reserved resource and / or COT from another WTRU. In some embodiments, a WTRU may receive an SCI from another WTRU that has reserved resources and / or COTs. The WTRU may determine whether the reserved resources and / or COTs are available. For example, if a reserved resource (e.g., a reserved COT) is available, the WTRU may include it in the set of resources used for selection and transmission. Otherwise, if the reserved resource is unavailable, the WTRU may exclude it from the set of resources used for selection and transmission. The WTRU may determine whether a reserved resource is available based on any of the QoS, CAPC, one or more LBT parameters, and SL-RSRP associated with the reserved resource and / or any of the QoS, CAPA, and one or more LBT parameters associated with the WTRU's data. In one example, if the CAPC associated with the WTRU's data is greater than the CAPC associated with the reserved resource, the WTRU may consider the reserved resource (e.g., determine it to be) available. Otherwise, the WTRU may consider the reserved resource (e.g., determine it to be) unavailable. In another example, if the CAPC associated with a reserved resource is greater than (e.g., a pre)configured threshold, the WTRU may consider the reserved resource as (e.g., determine) unavailable. Otherwise, the WTRU may consider the reserved resource as (e.g., determine) unavailable.

[0193] The availability of one or more time slots after the WTRU determines the COT of another WTRU. In some embodiments, the WTRU may determine the availability of resources for transmission and / or reservation. The WTRU may also determine the availability of one or more time slots following the COT of another WTRU. For example, the WTRU may determine whether one or more time slots following the COT of another WTRU are available based on one or any combination of the following two examples.

[0194] In the first example, the WTRU can determine whether one or more time slots following the COT of another WTRU are available based on the QoS of the TB and / or one or more LBT parameters of the WTRU. For example, if the QoS of the TB and / or the CAPC of the TB are less than a threshold, the WTRU can determine that the first time slot after the reserved COT of the other WTRU is available. For example, if the QoS of the TB and / or the CAPC of the TB are greater than a threshold and less than another threshold, the WTRU can consider (e.g., determine) one time slot after the reserved COT of the other WTRU as unavailable. For example, if the QoS of the TB and / or the CAPC of the TB are less than a threshold, the WTRU can consider (e.g., determine) N ≥ 2 time slots after the reserved COT of the other WTRU as unavailable. This scheme allows the WTRU to reserve time for the LBT following the COT of another WTRU.

[0195] In the second example, the WTRU can determine whether one or more time slots following the COT of another WTRU are available based on the QoS associated with the reserved COT and / or one or more LBT parameters associated with the reserved COT.

[0196] WTRU performs puncturing / rate matching on transmissions prior to reserved resources / COT of another WTRU. In some embodiments, the WTRU may rate-match / puncture a portion of the transmission resources in the last transmission preceding the reserved resources / COT of another WTRU. Hereinafter, rate-matching / puncturing a transmission can be used interchangeably with the WTRU procedure for determining the duration of a transmission, which may expect the WTRU not to perform transmissions of one or more symbols. The WTRU may then implicitly and / or explicitly indicate the puncturing / rate-matching duration or the transmission duration (e.g., in SCI), which can be used to support the receiving WTRU in decoding the TB. The rate-matching / puncturing duration can be determined based on one or any combination of the following four examples.

[0197] In the first example, the rate matching / puncturing duration can be determined based on (e.g., pre)configuration in the resource pool. In one example, the WTRU can be (e.g., pre)configured to puncture / rate match a portion of the resource in the last transmission prior to the reserved resource / COT. The WTRU can then follow (e.g., pre)configured values ​​to determine the duration of the puncturing / rate matching. In another example, the WTRU can be (e.g., pre)configured to stop transmissions of one or more symbols prior to the reserved resource (e.g., COT) of another WTRU. The WTRU can then determine when to stop transmissions.

[0198] In the second example, the rate matching / puncturing duration can be determined based on an implicit and / or explicit indication in a resource-reserved transmission (e.g., SCI). In one example, the WTRU can determine the rate matching / puncturing duration based on the indicated LBT duration (e.g., expected LBT duration) of the channel accessing the other WTRU (e.g., a WTRU reserving a resource / COT). The LBT duration can be indicated in the SCI. In another example, the WTRU can determine the rate matching / puncturing duration based on one or more LBT parameters (e.g., contention window value) and / or one or more QoS parameters (e.g., priority) indicated in the reserved WTRU's transmission (e.g., SCI).

[0199] In the third example, the rate matching / punch duration can be determined based on the QoS of the TB and / or one or more LBT parameters used for accessing the LBT subband.

[0200] In the fourth example, the rate matching / punch duration can be determined based on the CBR of the resource pool and / or LBT subband.

[0201] exist Figure 7 In one example shown, the WTRU can acquire the COT and perform a transmission within the vertical shaded rectangle shown at 701. The WTRU can (e.g., intends) perform two transmissions within the COT. In the final transmission, the WTRU can rate match / puncture several symbols to assist (e.g., aid) other WTRUs in performing LBTs (e.g., within the rectangle shown at 702).

[0202] WTRU performs puncturing / rate matching in the final transmission of its COT. The WTRU can determine the transmission duration in the last transmission of the COT. For example, the WTRU can perform puncturing / rate matching in the last transmission of its COT, which can be used to facilitate the LBT process of other WTRUs. The WTRU can determine any of the following: (i) whether to perform rate matching / puncturing in the last transmission of its COT; (ii) the duration of puncturing / rate matching; and (iii) the transmission duration of the last transmission of the COT.

[0203] The transmission and / or punch / rate matching duration of the final transmission can be determined based on one or any combination of the following four examples.

[0204] In the first example, the transmission duration for the last transmission and / or puncturing / rate matching can be determined based on whether the COT is shareable. For example, the WTRU can be (e.g., pre-)configured with the gap duration between the last transmission in the COT and the slot boundary for use with a shareable COT. The WTRU can determine the duration of the last transmission to be punctured / rate matched to satisfy the (e.g., pre-)configured gap between the last transmission and the slot boundary. For example, if the COT is not shareable, the WTRU can perform transmissions in a full slot. In this scenario, the WTRU can also use the last symbol as a protective symbol for Tx / Rx handover.

[0205] In the second example, the duration of the last transmission and / or puncturing / rate matching can be determined based on whether any reserved resources exist after the last transmission: for example, if any reserved resources exist after the last transmission, the WTRU can determine to perform puncturing / rate matching for a certain duration (e.g., one or more symbols) of its last transmission in the COT.

[0206] In the third example, the transmission and / or puncturing / rate matching duration of the last transmission can be determined based on the QoS of the TB and / or one or more LBT parameters used for accessing the LBT subband.

[0207] In the fourth example, the transmission and / or puncturing / rate matching duration of the last transmission can be determined based on the CBR of the resource pool and / or LBT subband.

[0208] WTRU determines puncturing / rate matching in simultaneous multiple LBT subband transmissions. In some embodiments, the WTRU can perform simultaneous transmissions across multiple LBT subbands. The WTRU can determine the transmission duration in the final transmission of the COT based on the transmission duration in each LBT subband. For example, the transmission duration across multiple LBT subbands could be the minimum (e.g., lowest) transmission duration of all LBT subbands. The WTRU can instruct another node (e.g., in the SCI) on the transmission duration of the multiple LBT subbands for broadband operation. This scheme allows the WTRU to complete its transmissions simultaneously for all LBT subbands.

[0209] WTRU terminates its COT for a certain period of time before reserving resources. A WTRU may terminate its COT (e.g., early COT termination) for a certain duration (e.g., one or more time slots) before another WTRU's reserved resources (e.g., reserved COT). The early COT termination duration may be determined based on the (pre)configuration of the resource pool and one or more LBT / QoS parameters of the reserved COT and / or any of the WTRUs. The one or more LBT / QoS parameters of the reserved COT may be indicated in the transmission (e.g., SCI) that reserved the COT. For example, the transmission stop duration may be determined based on the CAPC and / or contention window indicated in the reserved resources. This scheme allows the WTRU reserving the COT sufficient time to clear the channel before the reserved resources.

[0210] exist Figure 8 In one example shown, the WTRU can acquire a COT and perform a transmission within its COT, as illustrated in the vertical shaded rectangle at 801. The WTRU can determine a time slot not preceding a reserved COT of another WTRU to perform a transmission. That other WTRU can then perform an LBT (shown at 802) to clear the channel. A COT-reserved WTRU can perform a transmission within a reserved COT at 803.

[0211] The WTRU terminates its COT during the duration of its broadband operation. A WTRU can terminate its COT (e.g., early COT termination) within a duration (e.g., one or more time slots) for broadband operation (e.g., across multiple LBT subbands). For example, a WTRU can detect a reserved COT of another WTRU in one or more LBT subbands, and the WTRU can then determine to perform an early COT termination in those one or more LBT subbands (e.g., stopping transmission in one or more time slots prior to the reserved COT). The WTRU can perform early termination of the COT across the entire broadband. The duration of the early termination of the COT can be determined based on the early termination of each LBT subband. For example, the termination duration of the COT for broadband operation can be the longest termination among the set of LBT subbands for broadband operation (e.g., for each of those LBT subbands).

[0212] WTRU reserves resources for (e.g., potential) transmissions. The WTRU may reserve one or more resources (e.g., COT) for one or more (e.g., potential) transmissions. In one scenario, the WTRU may reserve one or more resources for performing LBT and / or transmissions. In another scenario, the WTRU may reserve one or more resources solely for transmissions. The WTRU may indicate (e.g., information indicating the transmission) whether the reserved resources are for LBT and / or transmissions. The WTRU may determine whether to reserve resources (e.g., future COTs) for future (e.g., upcoming) transmissions based on one or any combination of the following four examples.

[0213] In the first example, the WTRU can determine whether to reserve resources for one or more upcoming transmissions based on any of the QoS of the TB, SLRB, and LCH. For example, the WTRU can be (e.g., pre-)configured with conditions for reserving resources (e.g., future COTs) using (e.g., certain) QoS parameters. If the QoS of the TB is not satisfied, the WTRU may not reserve resources. Otherwise, the WTRU may reserve resources.

[0214] In the second example, the WTRU can determine whether to reserve resources for one or more upcoming transmissions based on the CBR of the resource pool and / or LBT subband. For example, the WTRU can be (e.g., pre-)configured with a range of CBRs for reserving resources (e.g., future COTs). If the CBR is within this range, the WTRU can determine to reserve resources. Otherwise, the WTRU may not reserve resources. The CBR range can be (e.g., pre-)configured as a function of the QoS of TB, SLRB, and LCH. The CBR range can be (e.g., pre-)configured as a function of the CAPC of TB, SLRB, and LCH.

[0215] In the third example, the WTRU can determine whether to reserve resources for one or more upcoming transports based on the CAPC of the SLRB and / or LCH. For example, the WTRU can be (e.g., pre-)configured with a range of CAPCs for reserving resources (e.g., future COTs). If the CAPCs of the TB, SLRB, and / or LCH are within this range, the WTRU can determine to reserve resources. Otherwise, the WTRU may not reserve resources. The CBR range can be (e.g., pre-)configured as a function of the QoS of any of the TB, SLRB, and LCH.

[0216] In the fourth example, the WTRU can determine whether to reserve resources for one or more upcoming transmissions based on one or more LBT parameters used for access resources. For example, the WTRU can be (e.g., pre-)configured with a contention window for reserving resources (e.g., future COTs). CW p The WTRU determines the scope of the contention window. If the contention window is within this scope, the WTRU can decide to reserve resources. Otherwise, the WTRU may not reserve resources.

[0217] WTRU postpones / delays its transmission to a future time slot. In some embodiments, the WTRU can postpone / delay its transmission to a future time slot when the LBT succeeds (e.g., the backoff counter reaches 0, N = 0). The WTRU may not postpone the transmission during the delay period ( T d The WTRU performs sensing to perform a transmission after N reaches 0. The WTRU can then continue its LBT (e.g., a short LBT) in a future time slot. If the time gap between a successful LBT and a reserved COT of another WTRU is less than a threshold, the WTRU can postpone its transmission. The WTRU can then continue its LBT and transmission after the reserved COT. This scheme allows the WTRU to select more resources for a transmission of TB. The time slot threshold that can be used to determine whether to postpone its transmission can be determined based on one or any combination of the following four examples.

[0218] In the first example, the time slot threshold can be determined based on (e.g., pre-)configuration in the resource pool. For example, if a successful LBT implementation is one time slot before a reserved COT for another WTRU, the WTRU can be (pre-)configured to postpone / delay its LBT and / or transmission. If the time slot between a successful LBT and a reserved COT for another WTRU is less than one time slot, the WTRU can postpone / delay its transmission.

[0219] In the second example, the time slot threshold can be determined based on the QoS of the TB. For example, the WTRU (e.g., pre-configured) can be configured with time slots for deferring / delaying its transmission based on the QoS of the TB (e.g., the reliability of the TB or the HARQ type). The WTRU can then determine the time slot threshold for deferring / delaying its transmission based on the QoS of the TB. If the time slot is within the determined time slot threshold, the WTRU can determine to defer / delay its LBT and / or transmission.

[0220] In the third example, the time slot threshold can be determined based on the QoS associated with the reserved COT of another WTRU.

[0221] In the fourth example, the time slot threshold can be determined based on the resource pool's CBR. For example, a WTRU can be (e.g., pre-)configured with a time slot threshold for delaying its transmission according to the resource pool's CBR. The WTRU can determine the time slot threshold for delaying / postponing its transmission based on the resource pool's CBR. The WTRU can determine whether to delay / postpone its transmission based on whether the time slot between a successful LBT and a reserved COT of another WTRU is greater than the determined time slot threshold.

[0222] exist Figure 9 In one example shown, the WTRU can successfully complete the LBT process before the reserved COT 92 of another WTRU, as shown at 91. The WTRU can postpone its transmission within the window between the LBT success time and the reserved COT of the other WTRU. The WTRU can continue its LBT as shown at 93 and can acquire a new COT 94 after the reserved COT 92 of that other WTRU.

[0223] WTRU determines which time slots cannot be used for LBT and transmission. In one embodiment, the WTRU can determine the set of time slots in which LBT and transmissions are to be performed. For example, the WTRU can perform LBT before a time slot boundary and can transmit PSCCH / PSSCH from the time slot boundary. The WTRU can consider (e.g., determine) the following time slots as unavailable for LBT and transmissions.

[0224] If frequency division multiplexing (FDM) between two WTRUs in the same time slot is not allowed in the resource pool, the WTRU can determine that the time slot reserved by the other WTRU is unavailable for LBT and transmission.

[0225] The WTRU can determine X time slots after the reserved time slot as unavailable for LBT and transmission. The WTRU can treat these as unusable for transmission (e.g., due to a conflict with the reserved WTRU). X can be an integer.

[0226] The WTRU can determine that Y time slots prior to the reserved time slot are unavailable for LBT and transmission. The WTRU can treat these as unusable for transmission (e.g., due to a conflict with the reserved WTRU). Y can be an integer.

[0227] The values ​​of X and / or Y can be determined based on one or any combination of the following examples.

[0228] In the first example, the values ​​of X and / or Y can be determined based on (e.g., pre)configuration in the resource pool. For example, the WTRU can be (e.g., pre)configured with the values ​​of X and Y (e.g., for a 15 kHz subcarrier spacing (SCS), X = 1, Y = 1; for a 30 kHz SCS, X = 2, Y = 2).

[0229] In the second example, the values ​​of X and / or Y can be determined based on the SCS configured in the resource pool (e.g., pre-configured). For example, the values ​​of X and Y can be higher for a higher SCS.

[0230] In the third example, the values ​​of X and / or Y can be based on one or more LBT parameters (e.g., CAPC, ...) used by the WTRU to access the channel. CW p , CW min,p CW max,p The value of X is determined by any one of the following: the initial value of the backoff counter N, the delay period, etc. For example, the value of X can be determined based on one or more LBT parameters used by the WTRU to access the channel. In one example, the WTRU can be (e.g., pre-)configured with the value of X according to CAPC. The WTRU can determine the value of X based on the CAPC used for accessing the channel.

[0231] In the fourth example, the values ​​of X and / or Y can be based on one or more LBT parameters (e.g., CAPC, ...) used by the WTRU that reserves time slots. CW p , CW min,p , CW max,p The value of Y is determined by any one of the following: the initial value of the backoff counter N, the delay period, etc. For example, the value of Y can be determined based on one or more LBT parameters used by the reserved WTRU to access the channel. In one example, the WTRU can be (e.g., pre-)configured with the value of Y according to CAPC. The WTRU can determine the value of Y based on the CAPC used by the reserved WTRU to access the channel.

[0232] WTRU determines which time slots are available for performing LBT and transmission. The WTRU can determine the set of available time slots for performing LBT and transport based on the set of unavailable time slots. For example, from the total set of time slots in the resource selection window, the WTRU can exclude the set of unavailable time slots. The remaining set of time slots can be considered (e.g., determined) as the set of available time slots. The WTRU can use the time slots from the set of available time slots to perform LBT and transport.

[0233] exist Figure 10 In one example shown, WTRU can perform resource allocation within the resource selection window. Figure 10 In this context, white time slot 1011 can be considered (e.g., determined to be) available. The WTRU can detect and determine that two reserved time slots 1012 and 1013 may exist, which can be considered (e.g., determined to be) unavailable for LBT and transmission. The WTRU can determine X = 2 time slots (e.g., after the elimination of the first reserved and unavailable time slot 1012) and Y = 1 time slot (e.g., before the second reserved and unavailable time slot 1013). The WTRU may not be able to transmit in the determined time slots. If frequency division multiplexing (FDM) between the two WTRUs is permitted and available frequency resources exist in the two reserved time slots (e.g., available interleaving), the WTRU can consider the two reserved time slots available. Otherwise, if FDM is not permitted, the WTRU can consider the two reserved time slots unavailable.

[0234] WTRU determines whether a reserved resource is available or unavailable. In one embodiment, the WTRU can perform resource selection in a resource selection window, where the WTRU can perform sensing by decoding the SCI in a sensing window preceding the resource selection window. If a resource is reserved in the resource selection window, the WTRU can determine whether the reserved resource is available based on one or more of the following two examples.

[0235] In the first example, the WTRU can determine whether a reserved resource is available based on the RSSI measured during a transmission that reserves the resource. For example, if the RSSI measured during a transmission that reserves the resource is greater than (e.g., a pre)configuration threshold, the WTRU can consider the resource unavailable. Otherwise, the WTRU can consider the resource available. The threshold can be based on an LBT energy detection threshold and (e.g., a pre)configuration offset.

[0236] In the second example, the WTRU may determine whether a reserved resource is available based on any of the following: (i) the CAPC of its data; (ii) the CAPC of the data associated with the reserved resource; and (iii) the relative CAPC of its data and the CAPC associated with the reserved resource.

[0237] exist Figure 11 In one example shown, if (1) the CAPC associated with the reserved resource is greater than the CAPC of its data and (2) the RSSI measured in the reserved transfer within the sensing window is greater than (e.g., a pre-configured threshold), then the WTRU can determine that a resource that can be reserved by another WTRU is unavailable. Figure 11 In this context, the white time slot shown at 1110 can be considered (e.g., determined to be) available.

[0238] WTRU prioritizes the slot(s)(s) in which LBT and transmission will be performed. After extracting the sensing results, the WTRU can determine the set of time slots to be used for LBT and transmission. The WTRU can determine which resource / time slot to prioritize based on any of the following: (i) time slots that are not reserved by any other WTRU; and (ii) time slots that are earlier in time.

[0239] WTRU process after LBT is not performed in the time slot allocated for single-channel resources to access the channel. In one embodiment, the WTRU may not perform an LBT to access the channel prior to the selected time slot used for performing LBT and transmission. The WTRU can then perform one or any combination of the following three options.

[0240] In the first option, WTRU can retain the current LBT parameters (e.g., N) and can continue to perform LBT in subsequent time slots.

[0241] In the second option, the WTRU can hop (e.g., continue) to the next pre-selected time slot. For example, in one scenario, the WTRU can pre-select X time slots from a set of Y time slots (e.g., by random selection) to perform LBT and transmission, where the values ​​of X and / or Y (e.g., any one of the maximum value of X, the maximum value of Y, the minimum value of X, and the minimum value of Y) can be (e.g., pre-)configured based on the QoS of the TB (e.g., any one of the remaining PDB and priority). In another scenario, the WTRU can pre-select X time slots from a sub-window (e.g., an earlier sub-window from the resource selection window) to perform LBT and transmission, where the value of X and / or the size of the sub-window can be (e.g., pre-)configured based on the QoS of the TB (e.g., any one of the remaining PDB and priority). If the WTRU fails to access the first pre-selected time slot, the WTRU can hop (e.g., continue) to the second pre-selected time slot to perform LBT and transmission. The WTRU can retain the current LBT parameters before hopping to the second pre-selected time slot. The WTRU can continue the process until it successfully performs LBT and transmission in one of the pre-selected time slots.

[0242] In the third option, the WTRU can use updated LBT parameters (e.g., N) to trigger resource selection (reselection) based on LBT failure. For example, the WTRU can first pre-select a time slot to perform LBT and transmission. If the WTRU fails to access the pre-selected time slot, it can trigger resource selection (reselection) based on LBT failure by determining the set of available time slots for performing LBT and transmission based on the updated LBT parameters (e.g., maintaining the current value of N), the resource selection window, and the QoS of the TB (e.g., remaining PDB). The WTRU can then pre-select another time slot to perform LBT and transmission. The WTRU can continue the process until it successfully performs LBT and transmission in one of the pre-selected time slots.

[0243] exist Figure 12 In one example shown, the WTRU might initially fail to perform LBT and transmission in a pre-selected time slot (e.g., time slot 4). Figure 12In this scenario, a white time slot can be considered available. The WTRU may have updated N = 1 before failing to perform LBT and transmission in time slot 4. In the first option 1210, the WTRU can continue performing LBT from time slot 4 until it successfully performs LBT and can transmit in the time slot. In the second option 1220, the WTRU can initially pre-select time slots 4, 5, and 10 to perform LBT and transmission. After the WTRU fails to perform LBT and transmission in time slot 4, it can jump to time slot 5 to perform LBT and transmission. The WTRU can use N = 1 as one of the updated LBT parameters. If the WTRU fails to perform LBT and transmission in time slot 5, it can jump to time slot 10 to perform LBT and transmission. In the third option 1230, the WTRU can trigger resource reselection based on LBT failure, where the WTRU can update the availability of each resource. For example, the WTRU can determine X = 0 during this resource selection (reselection) process. The WTRU can determine if unavailable slot 8 becomes available during the new resource selection (reselection) process. The WTRU can select one of the slots to perform LBT and transmission. The WTRU can use N=1 as one of the updated LBT parameters(s).

[0244] For broadband operations, WTRU determines which time slots can be used to perform LBT and transmission. For broadband operations, the WTRU can be (e.g., pre-)configured to select resources where at least M sets of RBs are adjacent to available resources (M is an integer). The WTRU can determine the available time slots to select. In one embodiment, the WTRU may consider (e.g., determine) a time slot with at least M adjacent available RB sets as an available time slot. In another embodiment, the WTRU may consider (e.g., determine) a time slot with at least M adjacent available RB sets, including a primary RB set, as an available time slot. For example, as... Figure 13 As shown, the WTRU can consider (e.g., determine) a time slot with two available RB sets as available. Specifically, the WTRU can consider (e.g., determine) time slots 5, 9, and 10 as available time slots.

[0245] WTRU is prioritized to perform LBT and transmission in time slots used for broadband transmission. After extracting the sensing results, the WTRU can determine the set of time slots in which LBT and transmission should be performed. The WTRU can determine which resource / time slot to prioritize based on one or any combination of the following: • A time slot considered available with at least (e.g., pre-configured) number of (e.g., adjacent) RB sets. • A time slot is considered available if it has at least (e.g., pre-configured) number (e.g., adjacent) RB sets including the primary RB set. • Time slots not reserved by any other WTRU • The earliest time slot in terms of time.

[0246] For broadband transmission, WTRU determines in which time slot LBT and transmission should be performed. The WTRU can determine in which time slot to perform LBT and transmission for broadband transmission based on a set of time slots having at least M (e.g., pre-configured) adjacent available RB sets. In one embodiment, the WTRU can select (e.g., a certain) number of time slots (e.g., X% of the time slots) in a sub-window (e.g., the earliest sub-window in a resource selection window). The WTRU can then (e.g., randomly) select one time slot in that window in which to perform LBT and transmission. In another embodiment, the WTRU can select (e.g., a certain) number of time slots that are the earliest available in time (e.g., X time slots). The WTRU can then (e.g., randomly) select one of the X time slots in which to perform LBT and transmission.

[0247] WTRU process after LBT is not performed in the time slot for multi-channel resource allocation to access the channel. In one embodiment, for broadband transmission, the WTRU may not perform LBT to access the channel before the selected time slot for performing LBT and transmission. The WTRU can then perform one or any combination of the following three options.

[0248] In the first option, the WTRU can continue performing LBT in subsequent available time slots. In one scenario, the WTRU can maintain the same primary RB set for LBT performance, and the WTRU can maintain updated LBT parameters (e.g., N) for LBT performance. In another scenario, the WTRU can change the primary RB set and can use a different set of LBT parameters to access the channel, which can be associated with the newly selected primary RB set.

[0249] In the second option, the WTRU can hop (e.g., continue) to the next pre-selected time slot. For example, the WTRU can pre-select X time slots from a set of Y time slots (e.g., by random selection) to perform LBT and transmission, where the values ​​of X and / or Y (e.g., any one of the maximum value of X, the maximum value of Y, the minimum value of X, and the minimum value of Y) can be (e.g., pre-)configured based on the QoS of the TB (e.g., any one of the remaining PDB and priority). In another example, the WTRU can pre-select X time slots from a sub-window (e.g., an earlier sub-window from the resource selection window) to perform LBT and transmission, where the value of X and / or the size of the sub-window can be (e.g., pre-)configured based on the QoS of the TB (e.g., any one of the remaining PDB and priority). If the WTRU fails to access the first pre-selected time slot, the WTRU can hop (e.g., continue) to the second pre-selected time slot to perform LBT and transmission. The WTRU can retain the current LBT parameters before hopping (e.g., continuing) to the second pre-selected time slot. The WTRU can continue the process until it successfully performs LBT and transmission in one of the pre-selected time slots.

[0250] In the third option, the WTRU can trigger resource selection (reselection) based on LBT failure using updated LBT parameters (e.g., N). For example, the WTRU can initially pre-select a time slot to perform LBT and transmission. If the WTRU fails to access the pre-selected time slot, it can trigger resource selection (reselection) based on LBT failure by determining a set of available time slots for performing LBT and transmission based on any of the updated LBT parameters (e.g., maintaining the current value of N), the resource selection window, and the QoS of the TB (e.g., remaining PDB). The WTRU can then pre-select another time slot to perform LBT and transmission. The WTRU can continue the process until it successfully performs LBT and transmission in one of the pre-selected time slots.

[0251] WTRU determines the main RB set WTRU can determine the primary RB set based on one or any combination of the following five examples (e.g., for type B LBT), for example, among multiple RB sets.

[0252] In the first example, WTRU can determine the primary RB set based on the CBR of each RB set (e.g., among the multiple RB sets). For example, WTRU can select the RB set that meets a condition (e.g., has the lowest CBR) as the primary RB set. For example, WTRU can select the RB set with a CBR less than a (pre)configured threshold as the primary RB set.

[0253] In the second example, the WTRU can determine the primary RB set based on its channel occupancy ratio (CR) (e.g., meeting certain conditions). For example, the WTRU can select the RB set with the lowest CR as the primary RB set.

[0254] In the third example, WTRU can determine the primary RB set based on the number of its reserved resources (e.g., those that meet the criteria) in the window. For example, WTRU can select the RB set with the minimum / maximum number of reserved resources in the window as the primary RB set.

[0255] In the fourth example, the WTRU can determine the RB set based on the number of resources transferred in the past (e.g., satisfying conditions). For example, the WTRU can select the RB set with the minimum / maximum number of transferred resources in the window as the primary RB set.

[0256] In the fifth example, the WTRU can determine the primary RB set based on the number of available resources / slots (e.g., conditions met). For example, the WTRU can select the RB set with the largest number of available resources / slots in a window (e.g., a resource selection window) as the primary RB set.

[0257] WTRU determines the primary RB set for switching. WTRU can trigger the main RB set (e.g., for type B LBT) based on one or any combination of the following events (e.g., a condition is met): • WTRU execution resource selection (reselection); • WTRU did not undergo LBT; • The number of consecutive times the WTRU has not undergone LBT (e.g., pre-configuration); The WTRU failed to access the channel after a certain period of time. • The CBR of the main RB set becomes greater than (e.g., pre)configured threshold; and • The CBR of another RB set becomes smaller (e.g., pre-configuration offset) than the CBR of the main RB set.

[0258] In broadband, the WTRU process is used for single-channel resource allocation without LBT (Level By-Test) after channel access. In one embodiment, during broadband operation, the WTRU may not perform LBT (Local Level Bypass) to access the channel prior to a selected resource in a set of RBs used to perform single-band transmission. The WTRU may perform one or any combination of the following four options.

[0259] In the first option, the WTRU can continue performing LBT on subsequent available resources within the same RB set. The WTRU can retain updated LBT parameters (e.g., N) to perform LBT in subsequent slots.

[0260] In the second option, the WTRU can jump to the next pre-selected time slot, which may be in the same or different set of RBs compared to the first pre-selected resources. For example, the WTRU may pre-select a certain number of available resources in which LBT and transmission will be performed (e.g., some). The set of pre-selected resources may be the set of available resources from a sub-window (e.g., from the earliest sub-window of the resource selection window) or selected from the set of resources that are X times earliest (e.g., randomly). In one embodiment, the WTRU may maintain a set of LBT parameters for all RB sets. The WTRU can use the updated LBT parameters (e.g., N) to access the channel in the next pre-selected resource. In another embodiment, the WTRU may use independent LBT parameters for each RB set.

[0261] In the third option, the WTRU can skip to the next pre-selected time slot. For example, the WTRU can pre-select X resources (e.g., by random selection) from the set of Y earliest time slots to perform LBT and transmission, where the values ​​of X and / or Y (e.g., any one of the maximum value of X, the maximum value of Y, the minimum value of X, and the minimum value of Y) can be (e.g., pre-)configured based on the QoS of the TB (e.g., any one of the remaining PDB and priority). Resources X and Y can be located in all (e.g., any) RB sets. In another example, the WTRU can pre-select X resources from a sub-window (e.g., an earlier sub-window from the resource selection window) to perform LBT and transmission, where the value of X and / or the size of the sub-window can be (e.g., pre-)configured based on the QoS of the TB (e.g., any one of the remaining PDB and priority). If the WTRU fails to access the first pre-selected time slot, the WTRU can skip to the second pre-selected time slot to perform LBT and transmission. In one scenario, the WTRU can maintain a set of LBT parameters for all RB sets. The WTRU can use updated LBT parameters (e.g., N) to access the channel in the next pre-selected resource. In another scenario, the WTRU can maintain independent LBT parameters for each RB set.

[0262] In the fourth option, the WTRU can trigger resource selection (reselection) based on LBT failure using updated LBT parameters (e.g., N). For example, the WTRU can initially pre-select a resource to perform LBT and transport. If the WTRU fails to access the pre-selected resource, it can trigger resource selection (reselection) based on LBT failure by determining a set of available resources for performing LBT and transport based on any of the updated LBT parameters (e.g., maintaining the current value of N), the resource selection window, and the QoS of the TB (e.g., remaining PDB). The WTRU can then pre-select another resource to perform LBT and transport. The WTRU can continue the process until it successfully performs LBT and transport in one of the pre-selected resources.

[0263] WTRU determines consistency LBT failure In one embodiment, the WTRU may maintain consistent (e.g., permanent, repeated) LBT failures per RB set. In another embodiment, the WTRU may maintain consistent (e.g., permanent, repeated) LBT failures per resource pool, which may include one or more RB sets. The WTRU may determine an LBT failure event (e.g., to be indicated to an upper layer) based on any of the following: (i) the WTRU did not perform an LBT to access a pre-selected resource; (ii) the WTRU did not perform an LBT to access a pre-selected time slot; (iii) the WTRU did not perform an LBT to transmit a TB; (iv) the WTRU did not receive a HARQ ACK feedback for the TB; (v) the WTRU did not receive a HARQ feedback for the transmission of the TB.

[0264] The WTRU determines which CAPC to use for accessing the channel. In one embodiment, the WTRU may determine which CAPC to use to access the channel based on any of the following: (i) the amount of data in each LCH and / or the amount of data associated with each CAPC; (ii) the CBR of the resource pool; and (iii) the maximum amount of data that can be transmitted in each COT, which may be associated with the CAPC associated with the COT.

[0265] For example, such as Figure 14As shown, the WTRU can determine to use CAPC1 to access the channel for a first case, as shown at 1410, and the WTRU can determine to use CAPC3 to access the channel for a second case, as shown at 1420. For example, in the first case, the buffer state of LCH1 may be full, and the WTRU can use CAPC1 to (e.g., only) transmit data in LCH1. For example, in the second case, the buffer states of all three LCHs may be low, and the WTRU can use CAPC3 to access the channel and transmit the entire data in a COT.

[0266] WTRU changes transmission bandwidth during COT duration In one embodiment, the WTRU can perform wideband transmission within a set of acquired RB sets when initiating a multichannel COT. The WTRU can determine to change the bandwidth of its transmission by discarding one or more RB sets and can continue to perform PSCCH / PSSCH transmissions in a smaller bandwidth (e.g., a subset of the acquired RB sets). The WTRU can allow other WTRUs to share a subset of the RB sets. The WTRU can instruct other WTRUs (e.g., by indicating, for example, by transmitting information) to share a subset of the RB sets (e.g., via SCI and / or MAC CE of PSCCH / PSSCH in the COT). The WTRU can determine to reduce its transmission bandwidth based on one or any combination of the following three examples of conditions.

[0267] In the first example of the condition, the WTRU can determine to reduce its transmission bandwidth based on the WTRU detecting another WTRU that has reserved a subset of the RB set in its broadband COT.

[0268] In the second example of the condition, the WTRU can determine to reduce its transmission bandwidth based on the WTRU's CR being greater than (e.g., a pre-configured threshold).

[0269] In the third example of the condition, the WTRU can determine to reduce its transmission bandwidth based on the WTRU's buffer state being less than (e.g., a pre-)configured threshold. For example, if the WTRU does not have enough data to justify transmission in broadband operation, the WTRU can reduce its transmission bandwidth for one or more remaining transmissions in the COT.

[0270] WTRU determines in which time slot LBT and transmission should be performed for multi-slot contiguous transmission. In one embodiment, the WTRU can be (e.g., pre-)configured to perform resource selection for a multi-consecutive-slot transmission (MCSt) of N consecutive slots (N being an integer). The WTRU can determine in which slot to begin LBT and transmission based on a set of slots with at least N adjacent available slots. In one embodiment, the WTRU can select (e.g., a certain number) of slots (e.g., X% of slots) within a sub-window (e.g., the earliest sub-window in the resource selection window). The WTRU can then (e.g., randomly) select one slot in that window in which to perform LBT and transmission. In another embodiment, the WTRU can select a certain number of time-first available slots (e.g., X slots). The WTRU can then (e.g., randomly) select one of the X slots in which to perform LBT and transmission.

[0271] After the WTRU performs a transmission within a COT, it determines in which time slot the LBT and transmission should be performed. In another embodiment, the WTRU can successfully acquire the COT and perform a transfer within the COT. After a successful transfer within the COT, in one embodiment, the WTRU can determine in which time slot to perform LBT and transfer after the COT based on one of the reserved time slots in the previous COT. Specifically, within the current COT, the WTRU can reserve another COT in the resource selection window. The WTRU can then perform LBT and transfer in the next reserved COT. In another scenario, the WTRU can trigger resource selection (reselection) after it may have already completed a transfer within the COT.

[0272] Methods for network-assisted resource allocation WTRU request sidechain resources In some embodiments, the WTRU may request sidechain resources from the network. The WTRU may implicitly / explicitly indicate one or more of the following information to the network.

[0273] In the first example, the WTRU may implicitly and explicitly indicate one or more LBT parameters for accessing the channel in past and / or future transmissions (e.g., the next transmission), such as any one of contention window and initialized backoff time.

[0274] In the second example, the WTRU may implicitly or explicitly indicate information associated with the expected transmission of the TB, such as the QoS of the data, the size of the TB, the modulation and coding scheme (MCS), and the number of transmissions for the TB.

[0275] A WTRU may explicitly indicate any piece of information described herein by transmitting explicit information indicating that piece of information. A WTRU may implicitly indicate any piece of information described herein by transmitting another piece of information associated with that (e.g., implicitly indicated) piece of information.

[0276] WTRU receives sidechain authorization from the network The WTRU can receive scheduling information from the network, which may include one or any combination of the following information.

[0277] In the first example, the scheduling information may indicate resources for one or more LBT subbands, which may include either the frequency or duration of the resources in each LBT subband. In one scenario, the WTRU may receive sidechain grant information with a fixed timing offset and duration. In another scenario, the WTRU may receive sidechain grant information as a sliding window with a flexible offset and fixed duration. For example, the WTRU may receive sidechain grant information within a window with an offset and a fixed duration (e.g., four time slots). The WTRU can acquire the channel for four time slots, regardless of when it can successfully perform LBT.

[0278] In the second example, the scheduling information may indicate one or more LBT parameters for accessing the channel.

[0279] In the third example, scheduling information can indicate the transmission duration for the last transmission for COT.

[0280] In the fourth example, scheduling information can instruct UL feedback resources, which can be used to report LBT and / or transmission results. For example, the WTRU can receive downlink control information (DCI) to instruct PUSCH resources to report the resource usage status of scheduled sidelink grants. The WTRU can use either MAC CE or RRC messages to report the resource usage status to the network. In another example, the WTRU can receive DCI (e.g., the same DCI for scheduling sidelink resources) to instruct Physical Uplink Control Channel (PUCCH) resources to report the resource usage status of scheduled sidelink grants. The WTRU can use uplink control information (UCI) (e.g., HARQ) to report the resource usage status of scheduled sidelink grants.

[0281] WTRU (e.g., trigger) reports UCI and / or MAC CE to the network. The WTRU can trigger reporting the results of LBT and / or transmissions in the scheduled sidechain grant from the network (e.g., sending feedback information indicating it). In one scenario, the WTRU can trigger sending feedback information such as a scheduling request (SR) to the network (e.g., only). In another scenario, the WTRU can trigger sending UCI (e.g., SR) and MAC CE (e.g., SL buffer status report (SL BSR)) to the network (e.g., both).

[0282] WTRU (e.g., trigger) sends UCI to the network. In one approach, the WTRU may be (e.g., pre-configured) with UCI resources (e.g., a dedicated SR for indicating the state of resource usage in a scheduled sidechain grant) to indicate the LBT and / or transport status related to the scheduled sidechain grant to the network. For example, the WTRU may be (e.g., pre-configured) with conditions that trigger the transmission of UCIs (e.g., SRs) related to LBTs and / or transports. The conditions that trigger the transmission of UCIs (e.g., SRs) may be based on one or any combination of the following four examples.

[0283] In the first example, the condition for sending a UCI (e.g., SR) can be based on the number / percentage of acquired LBT subbands relative to the scheduled LBT subbands. In one example, the WTRU can be scheduled using sidechain resources in two LBT subbands. For example, if the WTRU fails to acquire one or both LBT subbands, it can trigger (e.g., send) an SR to the network. In another example, the WTRU can trigger (e.g., send) an SR to the network only if it fails to acquire both LBT subbands.

[0284] In the second example, the conditions for sending a UCI (e.g., an SR) can be based on the number / percentage of acquired time slots relative to the number of scheduled time slots. In one example, the WTRU can be scheduled using sidechain resources in two LBT subbands spanning four time slots. If the WTRU fails to acquire one or two LBT subbands after two time slots, it can trigger (e.g., send) an SR to the network.

[0285] In the third example, the conditions for sending a UCI (e.g., an SR) can be based on the number / percentage of resources transmitted relative to the scheduled resources. In one example, the WTRU could be scheduled using sidechain resources across two LBT subbands spanning four time slots. If the WTRU fails to acquire 50% of the total scheduled sidechain resources, it can trigger (e.g., send) an SR to the network.

[0286] In the fourth example, the conditions for sending a UCI (e.g., SR) can be based on the remaining data in the buffer that meets further conditions. For example, if the data that the WTRU still has has a priority and / or delay that meets a threshold, the WTRU can trigger a UCI (e.g., SR).

[0287] The threshold for the number / percentage of acquired LBT subbands, slots and / or resources used to trigger the transmission of UCI and / or MAC CE can be any of the following: (e.g., pre-)configured and dynamically indicated to WTRU (e.g., via DCI).

[0288] WTRU triggers the MAC CE to be sent to the network. In some embodiments, the WTRU may trigger the sending of feedback information such as a MAC CE (e.g., SL-BSR) and / or an RRC message (e.g., WTRUAssistantInformation) to indicate the resource usage status (e.g., LBT and transport status, or the WTRU's buffer status) following the scheduled sidechain resource. The gNB can then know the amount of data the WTRU may have already transferred within the scheduled grant (e.g., based on the scheduled grant). The WTRU may be (e.g., pre-)configured with one or more conditions that trigger the sending of MAC CE and / or RRC messages to send such an indication. The conditions may be based on one or any combination of the following three examples.

[0289] In the first example, the conditions for sending feedback information indicating resource usage status (e.g., SL-BSR) can be based on the remaining buffer of the WTRU and / or the remaining buffer of the WTRU having a QoS that meets the conditions. For example, if the data still held by the WTRU has a priority and / or latency that meets a threshold, the WTRU can trigger the transmission of a MAC CE (e.g., SLBSR).

[0290] In the second example, the conditions for sending feedback information (e.g., SL-BSR) indicating the status of resource usage can be based on the amount / percentage of transmission and / or the amount / percentage of resources / LBT subbands used in the scheduled sidechain license.

[0291] In the third example, the condition for sending feedback information indicating resource usage status (e.g., SL-BSR) can be based on whether an SR may have already been sent. For example, if an SR associated with the resource usage status authorized by the scheduled sidechain is sent, the WTRU can trigger the sending of a MAC CE (e.g., SL BSR).

[0292] WTRU sends HARQ feedback to report resource usage. In one approach, the WTRU can send feedback information, such as a 1-bit HARQ feedback, in the PUCCH to report the transmission status of the scheduled sidechain authorization. In another approach, the WTRU can send a HARQ codebook in the PUCCH to send multiple bits of HARQ feedback. In the codebook, the WTRU can use 1 bit to report the status of a scheduled LBT subband. The number of bits in the HARQ codebook used for a scheduling can be a function of the number of LBT subbands (e.g., pre-)configured in the resource pool. When the WTRU sends a 1-bit HARQ feedback, the WTRU can determine whether to send an ACK or NACK based on any of the following: (i) the number / percentage of acquired LBT subbands relative to the scheduled LBT subbands; (ii) the number / percentage of acquired time slots relative to the number of scheduled time slots; and (iii) the number / percentage of transmitted resources relative to the number of scheduled resources.

[0293] For example, if the number / percentage of acquired LBT subbands, slots, and / or resources is greater than or equal to a threshold, the WTRU may send (e.g., affirmative) ACK feedback. Otherwise, the WTRU may send (e.g., negative) NACK feedback. The threshold for the number / percentage of acquired LBT subbands, slots, and / or resources used to provide ACK / NACK feedback can be either pre-configured or dynamically indicated to the WTRU (e.g., via DCI).

[0294] In the case where the WTRU sends an N-bit HARQ codebook, one bit can be associated with a scheduled LBT subband. The WTRU can determine whether to send an ACK or NACK for each LBT subband based on any of the following: (i) the number / percentage of time slots acquired in each LBT subband relative to the number of scheduled time slots; and (ii) the number / percentage of resources transmitted in each LBT subband relative to the number of scheduled resources.

[0295] For example, if the number / percentage of slots and / or resources acquired in each LBT subband is greater than or equal to a threshold, the WTRU may send (e.g., affirmative) ACK feedback. Otherwise, the WTRU may send (e.g., negative) NACK feedback for each LBT subband. The threshold for the number / percentage of acquired LBT subbands, slots, and / or resources used to provide ACK / NACK feedback can be either (e.g., pre) configured or dynamically indicated to the WTRU (e.g., via DCI).

[0296] The WTRU can be configured to trigger the transmission of a UCI (e.g., indicating a SR) and / or a MAC CE (e.g., indicating an SL-BSR) to the network based on whether the PUCCH is available in the sidechain scheduling DCI. For example, if the PUCCH used to report HARQ status (e.g., ACK / NACK) is not included in the sidechain scheduling DCI (e.g., DCI format 3_0), the WTRU may trigger the transmission of a UCI and / or MAC CE if the number (e.g., or percentage) of acquired slots and / or resources meets a condition (e.g., less than a pre-configured threshold). Otherwise, if the sidechain scheduling DCI includes (e.g., indicates) a PUCCH resource for reporting HARQ status, the WTRU may not trigger the transmission of a UCI and / or MAC CE, for example, regardless of the LBT status in the sidechain.

[0297] This document describes embodiments with examples of ratios between subsets of acquired (e.g., transmitted) resources and sets of scheduled resources. The embodiments described herein are not limited to ratios but are compatible with any function of acquired (e.g., transmitted) and scheduled resources used for transmitting feedback information (e.g., including any of HARQ ACK, HARQ NACK, SR, and SL-BSR).

[0298] Methods for use in protected frequency bands WTRU determines its transmission scheme in an LBT subband. A WTRU can acquire an LBT subband. A WTRU can execute one or any combination of the following three examples of transmission schemes within an LBT subband.

[0299] In the first example of the transmission scheme, the WTRU may not use the guard band.

[0300] In the second example of the transmission scheme, the WTRU can use a portion of the guard band in a transmission of the TB (e.g., half of the guard band).

[0301] In the third example of the transmission scheme, the WTRU can use the entire guard band between two adjacent LBT subbands.

[0302] WTRU determines its transmission scheme in multiple adjacent LBT subbands. The WTRU can acquire two adjacent LBT subbands. The WTRU can execute one or any combination of the following transmission schemes related to guard band usage.

[0303] In a transmission scheme, the WTRU can perform two transmissions of the same TB, where each transmission can be within its LBT subband and the guard band resources can be left unused by any transmission.

[0304] In another transmission scheme, the WTRU can perform two transmissions of the same TB, each of which can be within its LBT subband, wherein one of the two transmissions can occupy the entire or part of the guard band and the other transmission can not use the guard band.

[0305] In another transmission scheme, the WTRU can perform two transmissions of the same TB, where each transmission can be within its LBT subband and each transmission can occupy a portion (e.g., half) of the guard band.

[0306] In another transmission scheme, the WTRU can perform a single transmission across two LBT subbands (TB). In some embodiments, the WTRU may not use the guard band. In other embodiments, the WTRU may use a portion of the LBT subband. In yet another embodiment, the WTRU may use the entire guard band.

[0307] In another transmission scheme, the WTRU can perform two transmissions of different TBs, where each transmission can be within its LBT subband and the guard band resources can be left unused by any transmission.

[0308] In another transmission scheme, the WTRU can perform two transmissions of different TBs, each of which can be within its LBT subband. One of the two transmissions can occupy all or part of the guard band, and the other transmission can operate without using the guard band.

[0309] In another transmission scheme, the WTRU can perform two transmissions of different TBs, where each transmission can be within its LBT subband and each transmission can occupy a portion (e.g., half) of the guard band.

[0310] WTRU indicates the use of transmission schemes and guard bands for one or more LBT subbands. A WTRU can instruct another node (e.g., one or more receiver WTRUs) (e.g., by indication) (e.g., by transmission information) its transmission scheme and / or guard band usage in one or more LBT subbands. In one scenario, the indication can be communicated (e.g., by inclusion) in an SCI associated with one or more transmissions. In another scenario, the indication can be communicated (e.g., by transmission) using a higher-level message (such as, for example, any of NAS, PC5 RRC, and MAC CE). For example, a WTRU can use one or more SCIs (e.g., second-stage SCIs) associated with one or more transmissions of one or more TBs to indicate the transmission scheme and / or guard band usage for one or more TBs in a time slot. For example, a WTRU can transmit information indicating one or any combination of the following two examples.

[0311] In the first example, the WTRU can transmit information indicating whether the WTRU uses a time slot to transmit one or more TBs. For example, the information could indicate, for a TB transmitted in a time slot, whether the TB spans multiple LBT subbands or each transmission is within one LBT subband.

[0312] In the second example, the WTRU may transmit information indicating whether the guard band is used in the time slot and / or the bandwidth usage of the guard band and / or the guard band is used (e.g., full guard band or part of the guard band).

[0313] exist Figure 15 In one example shown, the WTRU can execute one of four transmission schemes and guard band usage for a TB that is transmitted simultaneously in two adjacent subbands, and one of three transmission schemes and guard band usage for two TBs that are transmitted in the same time slot, one of which can be associated with the transmission in the diagonal shaded rectangle shown at 1511 and the other TB can be associated with the transmission in the horizontal shaded rectangle shown at 1512.

[0314] WTRU determines whether to use the guard band for its transmission. In some embodiments, the WTRU may acquire two or more adjacent LBT subbands. The WTRU may determine a transmission scheme. The WTRU may determine whether to use a guard band and / or the bandwidth of the guard band for each transmission between two LBT subbands. The transmission scheme and guard band usage may be determined based on one or any combination of the following four examples.

[0315] In the first example, the transmission scheme and guard band usage can be determined based on (e.g., pre)configuration in the resource pool. For example, the WTRU can be (e.g., pre)configured in the resource pool to determine whether to use the guard band between two adjacent LBT subbands. The WTRU can follow the (pre)configuration in the resource pool.

[0316] In the second example, the transmission scheme and guard band usage can be determined based on instructions from the network. For example, the WTRU can receive a broadband sidechain license from the network. The WTRU can receive instructions from the network regarding which transmission scheme to use and / or whether to use a guard band. The WTRU can determine the transmission scheme and guard band usage based on these instructions from the network.

[0317] In the third example, the transmission scheme and guard band usage can be determined based on whether the WTRU initiates the COT or shares the COT with other WTRUs. For example, if the WTRU shares the COT with another WTRU, it can determine that the guard band is not applicable. For example, if the WTRU shares the COT with another WTRU, the WTRU can use a transmission scheme in which each transmission can be within an LBT subband.

[0318] In the fourth example, the transmission scheme and guard band usage can be determined based on the order of transmissions in the COT (e.g., whether the WTRU transmits the first or several TBs in the COT, or the last several TBs in the COT). For example, the WTRU can use one transmission scheme for the first N time slots and / or M TBs of the COT (e.g., each transmission can be within an LBT subband). For example, the WTRU can use another transmission scheme for transmissions after the first N time slots and / or after the first M TBs (e.g., one transmission of a TB spans multiple LBT subbands). M can be fixed at 1 TB and N can be configured and / or determined based on the WTRU's processing capacity (e.g., pre-configured). In another example, the WTRU may not use a guard band for the first N time slots and / or M TBs of the COT. Alternatively, the WTRU can use a guard band for time slots after the first N time slots and / or M TBs. M can be fixed at 1 TB and N can be configured and / or determined based on the WTRU's processing capacity (e.g., pre-configured).

[0319] WTRU determines whether to use a guard band based on the transmission scheme. The WTRU can determine whether to use a guard band and / or the guard band bandwidth for transmission based on the WTRU's transmission scheme. For example, if a transmission of a TB spans two LBT subbands, the WTRU can use the guard band. Alternatively, if each transmission of a TB is within one LBT bandwidth, the WTRU may not use the guard band. For example, if the WTRU performs transmissions of different TBs within a time slot, the WTRU may not use the guard band.

[0320] Methods for reducing SCI decoding WTRU determines which RB set should be decoded for SCI. In one embodiment, the WTRU may determine which RB sets should decode the SCI and / or which RB sets should prioritize SCI decoding based on any of the following: (i) indications received from another network element (such as, for example, another WTRU, a peer WTRU of a unicast session, a gNB, etc.); (ii) RSSI measurement results and SCI decoding status; and (iii) (e.g., the (pre)configured priority of each) RB set.

[0321] In the first example, the WTRU can determine which RB sets should decode the SCI and / or which RB sets should prioritize SCI decoding based on indications received from another network element (e.g., another WTRU, a peer WTRU in a unicast session, a gNB, etc.). In one example, the WTRU can be (e.g., pre-)configured to have (e.g., default) RB sets for broadcast communication. The WTRU can establish a unicast session with another WTRU. This other WTRU can send information indicating a request to communicate in another set of RB sets. The WTRU can perform sensing and decoding of the SCI in the set of RB sets indicated by the peer WTRU. In another example, the other WTRU can indicate a congestion level associated with transmission activity of other technologies (e.g., Wi-Fi) in an RB set (e.g., send information indicating the congestion level). If the indicated congestion level (e.g., CBR) meets a condition (e.g., greater than (e.g., pre-)configured threshold), the WTRU can stop decoding the SCI in that RB set. If the indicated congestion level (e.g., CBR) fails to meet a condition (e.g., less than a pre-configured threshold), the WTRU can continue decoding the SCI. In another example, the WTRU can determine its SCI decoding behavior within a set of RBs based on indications received from another WTRU. For example, if the CBR (e.g., associated with transmission activity of other technologies) meets a condition (e.g., greater than a pre-configured threshold), the WTRU can reduce its SCI decoding periodicity (e.g., the WTRU can decode the SCI every N time slots, where N is an integer). Otherwise (e.g., if the CBR is less than the threshold), the WTRU can decode the SCI, for example, every time slot / hourly slot.

[0322] In the second example, the WTRU can determine which RB sets should decode SCIs and / or which RB sets should prioritize SCI decoding based on either the RSSI measurement results or the SCI decoding status. For example, if the RSSI measured over a period of time meets a first condition (e.g., greater than (e.g., a pre-configured threshold) and if the number of decoded SCIs over a period of time meets a second condition (e.g., less than (e.g., a pre-configured) threshold), the WTRU can reduce the SCI decoding periodicity.

[0323] In the third example, the WTRU can determine which RB sets should decode the SCI and / or which RB sets should have their SCI decoding prioritized based on (e.g., pre-)configured periodicity for each RB set. For example, the WTRU can be (e.g., pre-)configured with prioritized decoding for (e.g., each) RB set. The WTRU can then prioritize which RB set should decode the SCI sequentially based on the associated priority of the SCI decoding for (e.g., each) RB set.

[0324] Tx WTRU determines the number of symbols used for automatic gain control (AGC) purposes. In one embodiment, for a transmission in the first start symbol of a time slot with multiple start symbols, the WTRU may determine whether to use one or two symbols for automatic gain control (AGC) based on the number of RB sets(one or more) configured in the resource pool and the bandwidth of the transmission.

[0325] For example, a WTRU can be (e.g., pre-)configured with multiple start symbols for PSCCH / PSSCH transmissions. If the WTRU transmits from the first symbol of a time slot, it can determine the number of symbols used for AGC purposes. The WTRU can indicate (e.g., in an SCI) the number of AGC symbols used for its PSCCH / PSSCH transmissions, which can be used to support Rx WTRU decoding of the transmissions. For example, if the WTRU uses a symbol for AGC, the WTRU can repeat the same bits for subsequent symbols. In one scenario, a Tx WTRU can determine the number of symbols used for AGC purposes. In another scenario, an Rx WTRU can determine the number of AGC symbols to be monitored. The number of symbols used for AGC can be determined based on any of the following: (i) the number of RG sets (e.g., pre-)configured in a resource pool; (ii) whether the PSCCH / PSSCH transmission spans a resource pool; and (iii) whether FDM is allowed for transmissions starting in the middle of a time slot (e.g., not starting at the beginning of a time slot).

[0326] In the first example, the WTRU can determine the number of symbols used for AGC based on the number of RB sets (e.g., pre-)configured in the resource pool. For example, if one RB set is pre-configured in the resource pool, the WTRU may include (or monitor) one symbol for AGC purposes. If multiple (e.g., more than one) RB sets are pre-configured in the resource pool, the number of AGC symbols may be equal to the number of pre-configured starting symbols in the time slot.

[0327] In the second example, the WTRU can determine the number of symbols based on whether the PSCCH / PSSCH transport spans (e.g., the entire) resource pool. For example, if the PSCCH / PSSCH transport spans (e.g., the entire) resource pool, the WTRU may include (or monitor) one AGC symbol. Otherwise (e.g., if the PSCCH / PSSCH transport does not span (e.g., the entire) resource pool (e.g., if the PSCCH / PSSCH transport is localized in a set of adjacent resources of the resource pool)), the WTRU may include (or monitor) multiple (e.g., more than one) AGC symbols (e.g., the number of AGC symbols may be equal to the (e.g., pre-)configured number of the starting symbols in the time slot).

[0328] In the third example, the WTRU can determine the number of symbols used for AGC based on whether FDM is allowed for transmissions starting in the middle of a time slot (e.g., not starting at the beginning of a time slot). For example, if FDM is not allowed for transmissions starting in the middle of a time slot, the WTRU may include (or monitor) one AGC symbol. Otherwise, the WTRU may include (or monitor) multiple (e.g., more than one) AGC symbols (e.g., the number of symbols used for AGC purposes may be equal to the (e.g., pre-)configured number of the starting symbols in the time slot).

[0329] Example of WTRU performing LBT subband reselection In one embodiment, WTRU can be based on conditions (e.g., CW p If the number of available slots for the LBT in the Resource Selection Window (RSW) is greater than the threshold, the system determines whether to maintain the current LBT subband or reselect another LBT subband to perform the LBT (e.g., for Type 1 LBT for multichannel access). If the conditions for switching to another LBT subband are met, the WTRU can switch to the LBT subband that meets the conditions (e.g., the LBT subband with the highest number of available slots, the LBT subband with the lowest number of available slots). CW p (any of the LBT subbands). More specifically, the WTRU may perform the following steps for the LBT subband reselection process.

[0330] In the first step, the WTRU can be (e.g., pre-)configured with one or more conditions (e.g., parameters) for reselecting LBT subbands to perform LBT and / or transmission. These conditions (e.g., parameters) may include any one of a contention window threshold, an initialized backoff threshold, and a threshold for the number of available slots in the RSW.

[0331] In the second step, the WTRU can be (e.g., pre-configured) with one or more conditions for selecting another LBT subband. These one or more conditions may include the LBT subband with the highest number of available time slots and the LBT subband with the lowest number of available time slots. CW p Any one of the LBT subbands.

[0332] In the third step, for example when TB arrives, WTRU can determine whether the LBT subband reselection condition has been met.

[0333] In the fourth step, if the LBT subband reselection condition is not met, the WTRU may perform LBT and / or transmission in the current LBT subband. Otherwise, the WTRU may determine the LBT subband that meets the LBT subband reselection condition and may perform LBT and / or transmission in the determined LBT subband.

[0334] Example of WTRU reporting the LBT and / or transmission status of the scheduled broadband resources. In one embodiment, the WTRU can receive sidechain grants across multiple LBT subbands. The WTRU can perform initial and blind retransmissions for the TB (e.g., simultaneously) within the set of acquired LBT subbands in a time slot, and can indicate this transmission scheme in the SCI. The WTRU can determine whether to report an ACK / NACK to the network based on the number of acquired LBT subbands and / or the number of transmissions made within the scheduled grants. For example, the WTRU can perform the following procedures for mode 1 resource allocation in unlicensed spectrum of the wideband sidechain.

[0335] In the first step, the WTRU can be (e.g., pre-)configured with the percentage of acquired LTB subbands for 1-bit ACK / NACK feedback for the scheduled broadband resources.

[0336] In the second step, the WTRU can receive sidechain authorization information for resource usage scheduled for feedback (e.g., 1-bit feedback) across multiple LBT subbands and UL resources.

[0337] In the third step, WTRU can perform LBT on the set of scheduled LBT subbands and can obtain a subset of LBT subbands for which LBT was successful (e.g., a subband was determined to be cleared).

[0338] In the fourth step, the WTRU can perform (e.g., simultaneously) initial transmission and blind retransmission on the acquired set of LBT subbands, and can indicate (e.g., simultaneously) the transmission of the set of LBT subbands in the SCI.

[0339] In the fifth step, the WTRU can determine whether to report an ACK or NACK to the network based on the number of LBT subbands acquired.

[0340] Examples of use of guard band In one embodiment, if the WTRU acquires two adjacent LBT subbands associated with a guard band, it can determine whether to use the guard band for broadband operation based on the TB's transmission scheme (e.g., whether the TB spans multiple LBT subbands or whether each transmission of the TB is within an LBT subband) and the transmission time slots in the COT. The WTRU can indicate (e.g., in the SCI) its transmission scheme and whether the guard band is used. For example, the WTRU can perform the following steps.

[0341] In the first step, WTRU can determine the set of LBT subbands used to perform LBT and (e.g., potential) transmissions.

[0342] In the second step, WTRU can perform LBT on a set of LBT subbands and can acquire a subset of LBT subbands.

[0343] In the third step, for each time slot in the acquired COT, the WTRU can determine one of the following transmission schemes: (i) each transmission of the TB can span across the acquired LBT subband; or (ii) each transmission of the TB can be within an LBT subband.

[0344] In the fourth step, the WTRU may determine whether to use any guard band within the set of LBT subbands based on: (1) whether it acquires two adjacent LBT subbands; (2) the selected transmission scheme; and (3) the time slot in the COT from which it can perform the transmission. For example, if the WTRU performs a transmission across a TB spanning the acquired adjacent LBT subbands, it may use the guard band. Otherwise, it may not use the guard band.

[0345] In the fifth step, the WTRU can perform transmissions on the acquired subset of the LBT subbands and can indicate its transmission scheme and whether the guard band can be used (e.g., in SCI).

[0346] Example method for reselecting LBT subbands Figure 16This diagram illustrates an example method 1600 for reselecting an LBT subband for use in a wideband sidelink transmission in unlicensed spectrum. Method 1600 can be implemented in a WTRU. As shown at 1610, the WTRU can determine whether a first condition for reselecting the LBT subband exists on a first subband currently selected by the WTRU for the transmission. As shown at 1620, if the condition does not exist, the WTRU can perform LBT on the first subband. As shown at 1630, if the condition exists, the WTRU can select a second subband for the wideband sidelink transmission in the unlicensed spectrum, and the WTRU can perform LBT on the second subband.

[0347] In various embodiments, the first condition may be a contention window when the first sub-band satisfies a threshold. CW p The size of ).

[0348] In various embodiments, selecting a second subband for broadband sidelink transmission in unlicensed spectrum may include selecting the subband with the highest number of available time slots.

[0349] In various embodiments, selecting a second subband for broadband sidelink transmission in unlicensed spectrum may include: selecting one with the lowest... CW p Sub-band.

[0350] In various embodiments, the WTRU may include a processor, receiver, transmitter, and memory that implement method 1600.

[0351] Example methods for broadband sidechain transmission in unlicensed spectrum Figure 17 This diagram illustrates an example method 1700 for wideband sidelink transmission in unlicensed spectrum. Method 1700 can be implemented in a WTRU. As shown at 1710, the WTRU can determine multiple LBT subbands on which LBT operations are to be performed. As shown at 1720, the WTRU can perform (e.g., execute) LBT operations on the determined multiple LBT subbands. As shown at 1730, based on the LBT operations, the WTRU can acquire a set of subbands comprising multiple subbands for a time period of data transmission (e.g., channel occupancy time or COT). As shown at 1740, for each time slot in the acquired set of subbands in the COT, the WTRU can select a transmission scheme. As shown at 1750, the WTRU can determine whether two subbands in the subband set are frequency-adjacent. As shown at 1760, if (1) the selected transmission scheme allows the TB to span multiple subbands and (2) two of the subbands in the subband set are adjacent in frequency, then the WTRU can use the guard band for transmitting data to transmit data over the subband set.

[0352] In various embodiments, the selected transmission scheme may be one of the following: (1) a scheme in which each transmission of TB can span a set of subbands; and (2) a scheme in which each transmission of TB can be limited to one subband.

[0353] In various embodiments, the WTRU can transmit instructions for the selected transmission scheme to the network.

[0354] In various embodiments, the WTRU can transmit an indication to the network whether a guard band is being used to transmit data.

[0355] In various embodiments, the WTRU may include a processor, receiver, transmitter, and memory that implement method 1700.

[0356] Example methods for selecting resources to perform LBT. Figure 18 This is a diagram illustrating an example method 1800 for selecting resources for performing LBT for wideband sidelink transmission in unlicensed spectrum. Method 1800 can be implemented in a WTRU. As shown at 1810, the WTRU can determine time slots that can be reserved by another WTRU. As shown at 1820, the WTRU can determine time slots that can be used to perform LBT based on time slots that can be reserved by another WTRU. As shown at 1830, the WTRU can determine whether time slots that can be reserved by another WTRU can also be used to perform LBT by determining whether the received RSSI in the transmission from the other WTRU that reserved the time slots meets a threshold. As shown at 1840, the WTRU can determine a set of time slots that can be used for LBT according to (1) time slots that can not be reserved by another WTRU and (2) time slots that can be reserved by another WTRU and for which the RSSI in the transmission from the other WTRU that reserved the time slots meets the threshold. As shown at 1850, the WTRU can prioritize time slots in the set of time slots. As shown at 1860, WTRU can select a time slot from the time slot set for performing LBT based on priority.

[0357] In various embodiments, determining the set of time slots that can be used to perform LBT may include: (1) determining any time slot within X time slots after a time slot that is determined to be reserved by another WTRU and corresponds to an RSSI that fails to meet a threshold as unavailable for performing LBT, where X may be an integer; and (2) determining any time slot within Y time slots before a time slot that is determined to be reserved by another WTRU and corresponds to an RSSI that fails to meet a threshold as unavailable for performing LBT, where Y may be an integer.

[0358] In various embodiments, prioritization may include assigning a time slot that may not be reserved by another WTRU a higher priority than a time slot that may be reserved by another WTRU.

[0359] In various embodiments, prioritization may include assigning a higher priority to slots that may be earlier in time compared to slots that may be later in time.

[0360] In various embodiments, determining the set of time slots available for LBT may be further based on the CAPC, which is determined to be a time slot reserved by another WTRU.

[0361] In various embodiments, determining the set of time slots available for LBT may include comparing the CAPC of data to be determined to be in a time slot reserved by another WTRU with the CAPC of the transmitted data at the WTRU.

[0362] In various embodiments, the WTR may include a processor, receiver, transmitter, and memory that implement method 1800.

[0363] Example method for reporting feedback information related to SL transmission to the network. Figure 19 This diagram illustrates an example method 1900 for reporting feedback information related to SL transmissions to the network. Method 1900 can be implemented in a WTRU. As shown at 1910, the WTRU can receive scheduling information from the network for one or more sidechain transmissions, indicating a set of scheduled resources. As shown at 1920, the WTRU can perform LBT on the set of scheduled resources to acquire a subset of resources from the set of scheduled resources. As shown at 1930, the WTRU can transmit sidechain control information indicating the acquired subset of resources. As shown at 1940, the WTRU can transmit data from the acquired subset of resources. As shown at 1950, the WTRU can transmit feedback information related to the one or more sidechain transmissions to the network based on the number of acquired resources and the number of scheduled resources (e.g., a ratio between them).

[0364] In various embodiments, the sidechain transmission of the one or more sidechain transmissions may include sidechain control information transmission and data transmission.

[0365] In various embodiments, the number of resources acquired may be the number of resources in a subset of the acquired resources.

[0366] In various embodiments, the number of resources scheduled can be the number of resources in the set of resources scheduled.

[0367] In various embodiments, the set of resources scheduled can span any of more than one LBT subband and more than one time slot.

[0368] In various embodiments, the acquired subset of resources can span more than one LBT subband.

[0369] In various embodiments, the WTRU can determine whether conditions associated with the number of resources acquired and the number of resources scheduled are met.

[0370] In various embodiments, the condition may be satisfied when the ratio between the number of resources acquired and the number of resources scheduled is above a threshold.

[0371] In various embodiments, the threshold can be either pre-configured in the WTRU or dynamically indicated in the downlink control information.

[0372] In various embodiments, feedback information can indicate a positive response if the conditions associated with the number of resources acquired and the number of resources scheduled are met.

[0373] In various embodiments, a positive response may include a positive HARQ feedback (such as a HARQ ACK).

[0374] In various embodiments, if it is determined that the conditions associated with the number of resources acquired and the number of resources scheduled are not met, the feedback information may indicate either a negative response or a request for more resources.

[0375] In various embodiments, a request for more resources may include either a scheduling request (SR) or a sidechain buffer status report (SL BSR).

[0376] In various embodiments, a negative response may include a negative HARQ feedback (such as, for example, HARQ NACK).

[0377] In various embodiments, the WTRU may receive configuration information indicating conditions associated with the number of resources acquired and the number of resources scheduled.

[0378] In various embodiments, the WTRU may include circuitry comprising a processor, receiver, transmitter, and memory configured to implement method 1900.

[0379] Example method for determining whether to keep the current LBT subband or select another LBT subband. Figure 20This diagram illustrates an example method 2000 for determining whether to maintain the current LBT subband or select another LBT subband. Method 2000 can be implemented in a WTRU. As shown at 2010, the WTRU can perform a first LBT operation in a first subband. As shown at 2020, the WTRU can determine whether a first condition associated with the first LBT operation is met. As shown at 2030, the WTRU can perform a second LBT operation in either the first subband or the second subband based on whether the first condition associated with the first LBT operation is met.

[0380] In various embodiments, if it is determined that a first condition associated with the first LBT operation is met, the second LBT operation can be performed in the first subband.

[0381] In various embodiments, if it is determined that the first condition associated with the first LBT operation is not met, the second LBT operation can be performed in the second subband.

[0382] In various embodiments, the first condition associated with the first LBT operation may be satisfied if the first competition window value associated with the first LBT operation is less than a first threshold.

[0383] In various embodiments, the first condition associated with the first LBT operation may be satisfied if the initialized backoff value associated with the first LBT operation is less than a second threshold.

[0384] In various embodiments, the first condition associated with the first LBT operation may be satisfied if the number of available time slots in the first resource selection window associated with the first LBT operation is greater than a third threshold.

[0385] In various embodiments, the second subband can be selected such that the second subband satisfies the second condition.

[0386] In various embodiments, the second subband may satisfy the second condition if the second competition window value associated with the second subband is less than the first competition window value associated with the first subband.

[0387] In various embodiments, the second subband may satisfy the second condition if it is associated with the smallest competing window value among a plurality of competing window values.

[0388] In various embodiments, the second subband may satisfy the second condition if the number of available time slots in the second resource selection window associated with the second subband is greater than the number of available time slots in the first resource selection window associated with the first subband.

[0389] In various embodiments, the second subband can satisfy the second condition when it is associated with the maximum number of available time slots in a resource selection window among a plurality of resource selection windows.

[0390] In various embodiments, the first condition and the associated first parameter may be pre-configured in WTRU.

[0391] In various embodiments, the WTRU may receive configuration information indicating a first condition and associated first parameters.

[0392] In various embodiments, the second condition and the associated second parameter may be pre-configured in the WTRU.

[0393] In various embodiments, the WTRU may receive configuration information indicating a second condition and associated second parameters.

[0394] In various embodiments, the WTRU may include circuitry comprising a processor, receiver, transmitter, and memory configured to implement method 2000.

[0395] Example methods for determining major LBT subbands Figure 21 This diagram illustrates an example method 2100 for determining a primary LBT subband. Method 2100 can be implemented in a WTRU. As shown at 2110, the WTRU can determine multiple channel state metrics for multiple LBT subbands. As shown at 2120, the WTRU can select an LBT subband from the multiple LBT subbands as the primary LBT subband for type B LBT based on the channel state metrics associated with LBT subbands that meet the criteria. As shown at 2130, the WTRU can use the selected LBT subband as the primary LBT subband to perform type B LBT operations in the multiple LBT subbands.

[0396] In various embodiments, the channel state metric associated with the LBT subband may include the channel busy ratio (CBR) of the LBT subband.

[0397] In various embodiments, the channel state metric associated with the LBT subband can satisfy the condition when the CBR of the LBT subband is below a first threshold.

[0398] In various embodiments, the channel state metric associated with the LBT subband can satisfy the condition when the CBR of the LBT subband is the lowest among the multiple CBRs associated with the multiple LBT subbands.

[0399] In various embodiments, the channel state metric associated with the LBT subband may include the channel occupancy ratio (CR) of the WTRU for the LBT subband.

[0400] In various embodiments, the channel state metric associated with the LBT subband can satisfy the condition if the CR of the WTRU for the LBT subband is below the second threshold.

[0401] In various embodiments, the channel state metric associated with the LBT subband can satisfy the condition when the CR of the WTRU for the LBT subband is the lowest CR among the multiple CRs associated with the multiple LBT subbands.

[0402] In various embodiments, the WTRU may include circuitry comprising a processor, receiver, transmitter, and memory configured to implement method 2100.

[0403] Example method for selecting a time slot in the resource selection window Figure 22 This diagram illustrates an example method 2200 for selecting a time slot in a resource selection window. Method 2200 can be implemented in a WTRU. As shown at 2210, the WTRU can determine the set of available resources in the resource selection window located at the beginning of the resource selection window. As shown at 2220, the WTRU can perform a first LBT operation to acquire a channel in a first resource in the set of available resources. As shown at 2230, the WTRU can determine that the first LBT operation failed to acquire a channel. As shown at 2240, the WTRU can perform a second LBT operation to acquire a channel in a second resource in the set of available resources.

[0404] In various embodiments, the set of available resources may be determined based on the number of available resources configured in the resource selection window.

[0405] In various embodiments, the number of available resources may be pre-configured in the WTRU.

[0406] In various embodiments, the WTRU may receive configuration information indicating the number of available resources.

[0407] In various embodiments, the first LBT operation can be used for the transmission of a transport block, and the number of available resources can be a function of the QoS of the transport block.

[0408] In various embodiments, the number of available resources can be a function of any one of one or more LBT parameters and the CBR of the resource pool.

[0409] In various embodiments, the set of available resources can be determined based on sub-windows of the resource selection window. In various embodiments, the sub-windows can be configured in size.

[0410] In various embodiments, the configuration size of the sub-window can be pre-configured in WTRU.

[0411] In various embodiments, the WTRU can receive configuration information indicating the configuration size of a sub-window.

[0412] In various embodiments, the first LBT operation can be used for the transmission of a transport block, and the configuration size of the sub-window can be a function of the QoS of the transport block.

[0413] In various embodiments, the configuration size of a sub-window can be a function of one or more LBT parameters and the CBR of the resource pool.

[0414] In various embodiments, the first LBT operation can be used for the initial transmission of a transport block.

[0415] In various embodiments, the set of available resources may be selected from multiple LBT subbands.

[0416] In various embodiments, the first resource may be randomly selected from the set of available resources.

[0417] In various embodiments, the second resource may be randomly selected from the next available resources in the set of available resources.

[0418] In various embodiments, the second resource can be selected as the next available resource in the set of available resources.

[0419] In various embodiments, the WTRU may include circuitry comprising a processor, receiver, transmitter, and memory configured to implement method 2200.

[0420] Example method for transmission in the first start symbol of a time slot with multiple start symbols Figure 23 This is a diagram illustrating an example method 2300 for transmission in the first start symbol of a time slot having multiple start symbols. Method 2300 can be implemented in a WTRU. As shown at 2310, the WTRU can receive scheduling information for sidelink transmissions from the network. In various embodiments, this scheduling information can indicate time slots with multiple start symbols. As shown at 2320, the WTRU can determine the number of symbols to be used for automatic gain control based on the number of LBT subbands in the resource pool. As shown at 2330, the WTRU can use the determined number of symbols for automatic gain control to transmit the sidelink transmission.

[0421] In various embodiments, when the number of LBT subbands in the resource pool is 1, the number of symbols to be used for automatic gain control can be 1.

[0422] In various embodiments, when the number of LBT subbands in the resource pool is greater than 1, the number of symbols to be used for automatic gain control can be equal to the number of LBT subbands in the resource pool.

[0423] In various embodiments, when the number of LBT subbands in the resource pool is greater than 1, the number of symbols to be used for automatic gain control can be equal to 2.

[0424] In various embodiments, the number of symbols may be further determined based on the bandwidth associated with the sidechain transmission.

[0425] In various embodiments, the number of symbols may be further determined based on whether the sidechain transfer crosses a resource pool.

[0426] In various embodiments, when the sidechain transmission spans the resource pool, the number of symbols to be used for automatic gain control can be equal to 1.

[0427] In various embodiments, where the sidechain transfer is localized in the set of adjacent resources in the resource pool, the number of symbols to be used for automatic gain control can be greater than 1.

[0428] In various embodiments, the number of LBT subbands in the resource pool may be pre-configured in WTRU.

[0429] In various embodiments, the WTRU may include circuitry comprising a processor, receiver, transmitter, and memory configured to implement method 2300.

[0430] Any features, variations, or embodiments described with respect to the methods are compatible with apparatus including components for processing any of the disclosed methods, apparatus including a processor configured to process any of the disclosed methods, computer program products including program code instructions, and non-transient computer-readable storage media storing program instructions.

[0431] Although the features and elements are provided above in specific combinations, those skilled in the art will appreciate that each feature or element can be used alone or in any combination with other features and elements. This disclosure is not limited in its description of the specific embodiments described herein, which are intended to be illustrative of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Elements, actions, or instructions used in this specification should not be construed as essential or indispensable to the invention unless expressly stated otherwise. In addition to those enumerated herein, functionally equivalent methods and apparatus within the scope of this disclosure will be apparent to those skilled in the art from the above description. Such modifications and variations are intended to fall within the scope of the appended claims. This disclosure is limited only to the items of the appended claims and the full scope of their equivalents. It should be understood that this disclosure is not limited to any particular method or system.

[0432] For simplicity, the above embodiments are discussed in terms of the terminology and structure of infrared functional devices (i.e., infrared transmitters and receivers). However, the embodiments discussed are not limited to these systems, but can be applied to other systems that use other forms of electromagnetic waves or non-electromagnetic waves (such as sound waves).

[0433] It should also be understood that the terminology used herein is for describing particular embodiments only and is not intended to be limiting. As used herein, the term “video” or the term “image” may mean any of a snapshot, a single image, and / or multiple images displayed on a time-based basis. As another example, when referred to herein, the term “user equipment” and its abbreviation “UE,” the term “remote,” and / or the term “head-mounted display” or its abbreviation “HMD” may mean or include (i) a wireless transmit and / or receive unit (WTRU); (ii) any of many embodiments of a WTRU; (iii) a device configured with some or all of the structure and functions of a WTRU for wireless and / or wired functions (e.g., shared via a mobile phone); (iv) a device configured with less than all the structure and functions of a WTRU for wireless and / or wired functions; and so on. Figures 1A to 1D Details of example WTRUs that may represent any WTRU described herein are provided. As another example, various disclosed embodiments are described above and below herein as utilizing head-mounted displays. Those skilled in the art will appreciate that devices other than head-mounted displays can be utilized, and some or all of this disclosure and the various disclosed embodiments can be modified accordingly without improper experimentation. Examples of such other devices may include drones or other devices configured to allow information to flow to provide an adapted realistic experience.

[0434] Furthermore, the methods described herein can be implemented in computer programs, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as internal hard disks and removable disks), magnetic-optical media, and optical media (such as CD-ROMs and digital multifunction discs (DVDs)). The processor associated with the software can be used to implement a radio frequency transceiver for WTRUs, UEs, terminals, base stations, RNCs, MMEs, EPCs, AMFs, or any host computer.

[0435] Variations of the methods, apparatus, and systems provided above are possible without departing from the scope of the invention. Given the wide variety of applicable embodiments, it should be understood that the illustrated embodiments are merely examples and should not be construed as limiting the scope of the appended claims. For example, embodiments provided herein include handheld devices that may include or utilize any suitable voltage source (such as a battery) to provide any suitable voltage.

[0436] Furthermore, in the embodiments provided above, references to processing platforms, computing systems, controllers, and other devices including processors are mentioned. These devices may include at least one central processing unit (“CPU”) and memory. According to the practice of those skilled in the art of computer programming, references to symbolic representations of actions, operations, or instructions can be executed by various CPUs and memories. Such actions and operations or instructions may be referred to as “being executed,” “being executed by the computer,” or “being executed by the CPU.”

[0437] Those skilled in the art will appreciate that the actions and symbols representing operations or instructions include the manipulation of electrical signals by the CPU. Electrical systems represent data bits that can cause a transformation or reduction of electrical signals and maintain data bits at memory locations in a memory system, thereby reconfiguring or otherwise altering the operation of the CPU, and other signal processing. The memory location maintaining the data bits is a physical location having specific electrical, magnetic, optical, or organic properties corresponding to or representing the data bits. It should be understood that the embodiments are not limited to the platforms or CPUs mentioned above, and other platforms and CPUs may support the provided methods.

[0438] Data bits can also be maintained on a computer-readable medium, including disks, optical disks, and any other volatile (e.g., random access memory (RAM)) or non-volatile (e.g., read-only memory (ROM)) mass storage system readable by the CPU. The computer-readable medium can include cooperative or interconnected computer-readable media that are exclusively present on the processing system or distributed among multiple interconnected processing systems that may be local or remote to the processing system. It should be understood that the embodiments are not limited to the memories mentioned above, and other platforms and memories may support the provided methods.

[0439] In the illustrative embodiments, any operations, processes, etc., described herein can be implemented as computer-readable instructions stored on a computer-readable medium. These computer-readable instructions can be executed by a processor of a mobile unit, network element, and / or any other computing device.

[0440] There is little difference between the hardware and software implementations of the system. The use of hardware or software typically (but not always, as the choice between hardware and software may become important in some contexts) represents a design choice that represents a cost-efficiency trade-off. Various vehicles may exist by which the processes and / or systems and / or other technologies (e.g., hardware, software, and / or firmware) described herein can be implemented, and the preferred vehicle may vary depending on the context in which the processes and / or systems and / or other technologies are deployed. For example, if the implementer determines that speed and accuracy are paramount, the implementer may choose a vehicle primarily based on hardware and / or firmware. If flexibility is paramount, the implementer may choose a vehicle primarily based on software implementation. Alternatively, the implementer may choose some combination of hardware, software, and / or firmware.

[0441] The above detailed description has illustrated various embodiments of the apparatus and / or process using block diagrams, flowcharts, and / or examples. Since such block diagrams, flowcharts, and / or examples include one or more functions and / or operations, those skilled in the art will understand that each function and / or operation within such block diagrams, flowcharts, or examples can be implemented individually and / or collectively by a wide variety of hardware, software, firmware, or virtually any combination thereof. In one embodiment, several portions of the subject matter described herein can be implemented via application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), and / or other integration formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein can be equivalently implemented in an integrated circuit as one or more computer programs running on one or more computers (e.g., implemented as one or more programs running on one or more computer systems), implemented as one or more programs running on one or more processors (e.g., implemented as one or more programs running on one or more microprocessors), implemented as firmware, or virtually any combination thereof, and in light of this disclosure, designing circuits and / or writing code for software and / or firmware will be well within the skill of those skilled in the art. Furthermore, those skilled in the art will appreciate that the mechanisms of the subject matter described herein can be distributed as a variety of program products, and that the illustrative embodiments of the subject matter described herein apply regardless of the specific type of signal-bearing medium used for the actual implementation of the distribution. Examples of signal-bearing media include, but are not limited to, the following: recordable media, such as floppy disks, hard disks, CDs, DVDs, digital tapes, computer memory, etc.; and transmission media, such as digital and / or analog communication media (e.g., fiber optic cables, waveguides, wired communication links, wireless communication links, etc.).

[0442] Those skilled in the art will recognize that it is common practice in the art to describe devices and / or processes in the manner set forth herein, and subsequently to use engineering practice to integrate such described devices and / or processes into data processing systems. That is, at least a portion of the devices and / or processes described herein can be integrated into a data processing system through a reasonable amount of experimentation. Those skilled in the art will recognize that a typical data processing system typically includes one or more of the following: a system unit housing, a video display device, memory (such as volatile and non-volatile memory), a processor (such as a microprocessor and a digital signal processor), computing entities (such as an operating system, drivers, a graphical user interface, and applications), one or more interactive devices (such as a touchpad or screen), and / or a control system including feedback loops and control motors (e.g., feedback for sensing position and / or speed, control motors for moving and / or adjusting components and / or quantities). A typical data processing system can be implemented using any suitable commercially available components, such as those commonly found in data computing / communication and / or network computing / communication systems.

[0443] The topics described herein sometimes illustrate different components that are included within or connected to different other components. It should be understood that the architectures depicted are merely examples, and in fact, many other architectures that achieve the same functionality can be implemented. Conceptually, any arrangement of components that achieve the same functionality is effectively “associated” to enable the desired functionality. Therefore, any two components combined in this document to achieve a particular function can be considered “associated” with each other to enable the desired functionality, regardless of the architecture or intermediate components. Similarly, any two components so associating can also be considered “operably connected” or “operably coupled” to each other to achieve the desired functionality, and any two components that can be so associating can also be considered “operably coupled” to each other to achieve the desired functionality. Specific examples of operational coupling include, but are not limited to, physically paired and / or physically interacting components and / or wirelessly interacting and / or logically interacting and / or potentially interacting components.

[0444] Regarding the use of virtually any plural and / or singular terms herein, those skilled in the art can convert from plural to singular and / or from singular to plural where appropriate for the context and / or application. For clarity, various singular / plural permutations may be explicitly described herein.

[0445] Those skilled in the art will understand that, in general, the terminology used herein, and especially in the appended claims (e.g., the body of the appended claims), is intended to be “open” terms (e.g., the term “comprising” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “including” should be interpreted as “including but not limited to,” etc.). Those skilled in the art will further understand that if the intent is a specific number recited in the introduced claim, such intent will be explicitly stated in the claim, and if such a statement is not made, such intent does not exist. For example, the term “single” or similar language may be used where the intent is only one item. As an aid to understanding, the appended claims and / or the description herein may include the use of introductory phrases such as “at least one” and “one or more” to introduce the recitation of the claims. However, the use of such phrases should not be construed as implying that the introduction of a claim by the indefinite article “a” or “an” will include any particular claim contained in such an introduction limited to an embodiment containing only one such claim, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and / or “an” should be interpreted as meaning “at least one” or “one or more”). The same applies to the use of definite articles used to introduce a claim. Furthermore, even if a specific number is explicitly stated in the introduced claim, those skilled in the art will recognize that such a statement should be interpreted as meaning at least the number stated (e.g., an unmodified statement of “two statements” without other modifiers means at least two statements or two or more statements). Furthermore, in instances where a convention similar to "at least one of A, B, and C" is used, generally, in the sense that a person skilled in the art would understand, such a construction is intended (e.g., "a system having at least one of A, B, and C" will include, but is not limited to, a system having only A, a system having only B, a system having only C, a system having both A and B, a system having both A and C, a system having both B and C, and / or a system having both A, B, and C, etc.). In instances where a convention similar to "at least one of A, B, or C" is used, generally, in the sense that a person skilled in the art would understand, such a construction is intended (e.g., "a system having at least one of A, B, or C" will include, but is not limited to, a system having only A, a system having only B, a system having only C, a system having both A and B, a system having both A and C, a system having both B and C, and / or a system having both A, B, and C, etc.).Those skilled in the art will further understand that virtually any disjunctive terms and / or phrases presenting two or more alternative terms, whether in the specification, claims, or drawings, should be understood to include the possibility of including one, any, or both of the terms. For example, the phrase “A or B” would be understood to include the possibility of “A” or “B” or “A and B”. Further, as used herein, the term “any one of…” followed by a list of items and / or categories of items is intended to include, alone or in combination with other items and / or categories of items, “any one,” “any combination,” “any plurality,” and / or “any combination of plurality”. Additionally, as used herein, the term “set” is intended to include any number of items, including zero. Furthermore, as used herein, the term “number” is intended to include any number, including zero. Moreover, as used herein, the term “plural” is intended to be synonymous with “multiple.”

[0446] Furthermore, where features or aspects of this disclosure are described in accordance with the Markush group, those skilled in the art will recognize that this disclosure is therefore also described in accordance with any individual member or subgroup of the Markush group.

[0447] As those skilled in the art will understand, for any and all purposes, such as in providing a written description, all scopes disclosed herein also encompass any and all possible subscopes and combinations thereof. Any listed scope can be readily identified as adequately describing the same scope and capable of being decomposed into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each scope discussed herein can be readily decomposed into a lower third, middle third, and upper third, etc. As those skilled in the art will also understand, all language such as “up to,” “at least,” “greater than,” “less than,” etc., includes the stated number and refers to a scope that can subsequently be decomposed into subscopes as discussed above. Finally, as those skilled in the art will understand, a scope includes each individual member. Thus, for example, a group having 1 to 3 units refers to a group having 1, 2, or 3 units. Similarly, a group having 1 to 5 units refers to a group having 1, 2, 3, 4, or 5 units, and so on.

[0448] Furthermore, claims should not be construed as limited to the provided order or elements unless otherwise stated. Additionally, the use of the term "means for..." in any claim is intended to invoke 35 USC §112, ¶ 6 or the "means plus function" claim format, and any claim not containing the term "means for..." is not intended to do so.

[0449] As examples, suitable processors include general-purpose processors, special-purpose processors, traditional processors, digital signal processors (DSPs), multiple microprocessors, one or more microprocessors associated with a DSP core, controllers, microcontrollers, application-specific integrated circuits (ASICs), application-specific standard products (ASSPs); field-programmable gate array (FPGA) circuits, any other type of integrated circuit (IC), and / or state machines.

[0450] WTRU can be used in conjunction with hardware and / or software-defined radio (SDR) modules and other components, such as cameras, video phone modules, video phones, speakerphones, vibration devices, speakers, microphones, TV transceivers, hands-free phones, keyboards, Bluetooth modules, FM radio units, near field communication (NFC) modules, liquid crystal display (LCD) units, organic light-emitting diode (OLED) units, digital music players, media players, video game player modules, internet browsers, and / or any wireless local area network (WLAN) or ultra-wideband (UWB) modules.

[0451] Although various embodiments have been described with respect to the communication system, it is conceivable that the system can be implemented in software on a microprocessor / general-purpose computer (not shown). In some embodiments, one or more of the functions of the various components can be implemented in software that controls the general-purpose computer.

[0452] Furthermore, although the invention has been described and illustrated herein with reference to specific embodiments, it is not intended to be limited to the details shown. Rather, various modifications to the details may be made within the scope of the claims and without departing from the invention.

Claims

1. A method implemented in a wireless transmit / receive unit (WTRU), the method comprising: Receive scheduling information from the network for transmission of at least one sidechain, wherein the scheduling information indicates a set of multiple adjacent resource blocks (RBs); Listen-before-speak (LBT) is performed in the plurality of adjacent RB sets; as well as In response to a successful LBT in the plurality of adjacent RB sets, the at least one sidechain transmission is transmitted in the plurality of adjacent RB sets, wherein the at least one sidechain transmission includes sidechain control information indicating the plurality of adjacent RB sets for transmitting the at least one sidechain transmission.

2. The method of claim 1, wherein the plurality of adjacent RB sets includes a plurality of adjacent LBT subbands.

3. The method of claim 1, wherein the scheduling information further indicates any one of the frequency and duration of the resources of the plurality of adjacent RB sets.

4. The method of claim 1, wherein the scheduling information further indicates one or more parameters to be used for performing LBT in the plurality of adjacent RB sets.

5. The method of claim 4, wherein performing LBT in the plurality of adjacent RB sets comprises: The LBT is performed according to one or more parameters indicated.

6. The method of claim 1, wherein the at least one sidechain transmission includes either a physical sidechain control channel (PSCCH) transmission or a physical sidechain shared channel (PSSCH) transmission.

7. The method of claim 1, wherein the scheduling information further indicates Physical Uplink Control Channel (PUCCH) resources for reporting Hybrid Automatic Repeat Request (HARQ) feedback information related to the at least one sidelink transmission.

8. The method of claim 7, further comprising: HARQ feedback information related to the at least one sidechain transmission is transmitted in the PUCCH resource.

9. The method of claim 8, wherein the HARQ feedback information indicates the resource usage status associated with the at least one sidechain transmission.

10. The method of claim 8, wherein the HARQ feedback information indicates an affirmative response.

11. A method implemented in a wireless transmit / receive unit (WTRU), the method comprising: Receive scheduling information from the network for transmission of at least one sidechain, wherein the scheduling information indicates: (i) a set of multiple adjacent resource blocks (RBs); and (ii) Physical uplink control channel (PUCCH) resources for reporting hybrid automatic repeat request (HARQ) feedback information related to the at least one sidelink transmission; Listen-before-speak (LBT) is performed in the plurality of adjacent RB sets; as well as In response to LBT failing in at least one of the plurality of adjacent RB sets, a HARQ negative acknowledgment (NACK) is transmitted in the PUCCH resource.

12. The method of claim 11, wherein the plurality of adjacent RB sets comprises a plurality of adjacent LBT subbands.

13. The method of claim 11, wherein the scheduling information further indicates any one of the frequency and duration of the resources of the plurality of adjacent RB sets.

14. The method of claim 11, wherein the scheduling information further indicates one or more parameters to be used for performing LBT in the plurality of adjacent RB sets.

15. The method of claim 14, wherein performing LBT in the plurality of adjacent RB sets comprises: The LBT is performed according to one or more parameters indicated.

16. The method of claim 11, wherein the at least one sidechain transmission includes either a physical sidechain control channel (PSCCH) transmission or a physical sidechain shared channel (PSSCH) transmission.

17. A wireless transmit / receive unit (WTRU) including circuitry, said circuitry comprising a transmitter, a receiver, a processor, and a memory, configured to: Receive scheduling information from the network for transmission of at least one sidechain, wherein the scheduling information indicates: (i) a set of multiple adjacent resource blocks (RBs); and (ii) Physical uplink control channel (PUCCH) resources for reporting hybrid automatic repeat request (HARQ) feedback information related to the at least one sidelink transmission; Listen-before-speak (LBT) is performed in the plurality of adjacent RB sets; Under the condition that LBT is successful in the plurality of adjacent RB sets, the at least one sidechain transmission is transmitted in the plurality of adjacent RB sets, wherein the at least one sidechain transmission includes sidechain control information indicating the plurality of adjacent RB sets for transmitting the at least one sidechain transmission; as well as If the LBT fails in at least one of the plurality of adjacent RB sets, a HARQ negative acknowledgment (NACK) is transmitted in the PUCCH resource.

18. The WTRU of claim 17, wherein the plurality of adjacent RB sets comprises a plurality of adjacent LBT subbands.

19. The WTRU of claim 17, wherein the scheduling information further indicates any one of the frequency and duration of the resources of the plurality of adjacent RB sets.

20. The WTRU of claim 17, wherein the scheduling information further indicates one or more parameters to be used for performing LBT in the plurality of adjacent RB sets.

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