Measurement-based carrier selection in multicarrier sidelink

Abstract

A wireless transmit and receive unit (WTRU) may be configured to prioritize carriers with available sensing results from inter-UE coordination (IUC) during carrier selection and logical channel prioritization (LCP). The WTRU may be configured to identify a carrier and determine that the carrier has associated IUC information, which may include sensing measurements. The WTRU may select the carrier from a plurality of carriers based on the carrier having the associated IUC information. In the selection based on the IUC information associated with the carrier, the WTRU may preferentially select the carrier rather than other carriers. The WTRU may associate a first CBR threshold with the carrier based on the IUC information associated with the carrier. The WTRU may select data for transmission based on the first CBR threshold associated with the carrier.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 395,475, filed on August 5, 2022, the disclosure of which is incorporated herein by reference in its entirety. Background Art

[0003] Mobile communications using wireless communications continue to evolve. The fifth generation may be referred to as 5G. Previous (legacy) mobile communications may be, for example, fourth generation (4G) Long Term Evolution (LTE). Summary of the invention

[0004] Systems, methods, and means for measurement-based carrier selection are disclosed.

[0005] A wireless transmit and receive unit (WTRU) may identify a first carrier and a second carrier and may receive inter-UE coordination (IUC) information that may be associated with one of the carriers. The WTRU may receive data for transmission, wherein the data may have an associated data priority. If the WTRU determines that the data priority is above a priority threshold and the first carrier is associated with the IUC information, the WTRU may determine that a first channel busy rate (CBR) associated with the first carrier satisfies a first CBR threshold and may determine that the first carrier is selectable.

[0006] In the event that the WTRU determines that the data priority is above the priority threshold and the second carrier is not associated with IUC information, the WTRU may determine that a second CBR associated with the second carrier satisfies a second CBR threshold and may determine that the second carrier is available for selection. The first CBR threshold may be higher than the second CBR threshold.

[0007] The WTRU may select a sidelink grant on the first carrier. In the event that the WTRU determines that the first CBR associated with the first carrier is above the second CBR threshold, the WTRU may select to send data associated with a data priority above the priority threshold on the first carrier. In the event that the WTRU determines that the first CBR associated with the first carrier is not above the second CBR threshold, the WTRU may select to send data from a highest priority channel on the first carrier. The WTRU may transmit the selected data using the sidelink grant on the first carrier.

[0008] The WTRU may determine that a third carrier is associated with IUC information and a fourth carrier is not associated with IUC information. The WTRU may receive second data having an associated second data priority. In the event that the WTRU determines that the second data priority is below the priority threshold, the WTRU may determine that the third carrier is available for selection based on a third CBR associated with the third carrier satisfying the second CBR threshold. The WTRU may determine that the fourth carrier is available for selection based on a fourth CBR associated with the fourth carrier satisfying the second CBR threshold. The WTRU may select a sidelink grant on the third carrier and may transmit data of any priority on the third carrier.

[0009] The WTRU may be configured to prioritize carriers with available sounding results from IUC during carrier selection and logical channel prioritization (LCP). The WTRU may be configured to identify a carrier and determine that the carrier has associated IUC information, which may include sounding measurement results. The WTRU may select the carrier from a plurality of carriers based on the carrier having the associated IUC information. In the selection based on the IUC information associated with the carrier, the WTRU may select the carrier over other carriers.

[0010] The WTRU may operate in an autonomous resource allocation mode, such as Mode 2. The WTRU may receive new data on a logical channel. In response to receiving the data, the WTRU may trigger carrier and resource reselection for a new HARQ process. The WTRU may determine whether it has received, for example, recently received, an IUC containing preferred / non-preferred resource sets for one or more carriers.

[0011] The WTRU may determine a priority associated with the newly received data. If the WTRU determines that the priority of the data may be above a threshold, the WTRU may determine to use a different (e.g., higher) CBR threshold for carrier selection for carriers for which IUC information may be available than for carriers for which IUC information may not be available. If the WTRU determines that the priority of the data may not be above the threshold, the WTRU may determine to use a single (e.g., the same) CBR threshold for carrier selection for both carriers for which IUC information may be available and carriers for which IUC information may not be available.

[0012] The WTRU may be configured to select one or more allowed carriers, starting with the carrier where IUC information may be available, and thereafter in order of increasing CBR level.The WTRU may first select a carrier that has associated IUC information.

[0013] The WTRU may be configured to select a sidelink grant on the selected carrier. The WTRU may be configured to determine whether the grant occurs on a carrier whose associated CBR may be above a threshold associated with a carrier without associated IUC information. If the grant occurs on a carrier whose associated CBR may be above a threshold associated with a carrier without associated IUC information, the WTRU may select the data from the highest priority logical channel that has available data and whose priority may be above the threshold. If the WTRU determines that the grant occurs on a carrier whose associated CBR may not be above the threshold, the WTRU may determine to select the data from the highest priority logical channel that has available data. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented.

[0015] Figure 1B is an example of a method that can be used according to an embodiment of the present invention. Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within an illustrated communication system.

[0016] Figure 1C is an example of a method that can be used according to an embodiment of the present invention. Figure 1A System diagram of an example Radio Access Network (RAN) and an example Core Network (CN) for use within an illustrated communication system.

[0017] Figure 1D is an example of a method that can be used according to an embodiment of the present invention. Figure 1A System diagram of another example RAN and another example CN for use within the illustrated communication system.

[0018] Figure 2 Example implementations of carrier selection are depicted. DETAILED DESCRIPTION

[0019] A more detailed understanding may be obtained from the following description given by way of example in conjunction with the accompanying drawings.

[0020] Figure 1A1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of 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 discrete Fourier transform (DFT) spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multi-carrier (FBMC), etc.

[0021] 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, but it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a “station” and / or “STA”) may be configured to send and / or receive wireless signals and may include a user equipment (WTRU), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0022] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device that is configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an evolved Node B (eNB), a Home Node B, a Home evolved Node B, a next generation Node B (gNB), an NR Node B, a site controller, an access point (AP), a wireless router, and the like. Although the base stations 114a, 114b are each depicted as a single element, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0023] 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 (BSC), radio network controllers (RNC), relay nodes, etc. Base station 114a and / or base station 114b may be configured to send and / or receive wireless signals on one or more carrier frequencies (which may be referred to as cells (not shown)). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of a licensed spectrum and an unlicensed spectrum. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may also be 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 an embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to send and / or receive signals in a desired spatial direction.

[0024] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0025] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 115 / 116 / 117. WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​UL Packet Access (HSUPA).

[0026] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA) that may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro).

[0027] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using New Radio (NR).

[0028] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may together implement LTE radio access and NR radio access, for example using the dual connectivity (DC) principle. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0029] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), and GSM EDGE (GERAN).

[0030] Figure 1A The base station 114b in may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in local areas such as commercial venues, homes, vehicles, campuses, industrial facilities, sky corridors (e.g., for use by drones), and roads. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology (such as IEEE 802.11) to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology (such as IEEE 802.15) to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or a femtocell. As Figure 1A As shown, base station 114b may have a direct connection to Internet 110. Therefore, base station 114b may not need to access Internet 110 via CN 106 / 115.

[0031] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not described in detail in the text and video, the CN 106 / 115 may be configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Figure 1AAlthough not shown in the figure, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0032] The CN 106 / 115 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0033] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0034] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0035] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors 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) and state machine, etc. The processor 118 may perform signal decoding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0036] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from a base station via an air interface 116. For example, in one embodiment, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In an embodiment, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, an IR, UV, or visible light signal. In another embodiment, the send / receive element 122 may be configured to send and / or receive both an RF signal and an optical signal. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0037] Although the transmit / receive element 122 Figure 1B Although depicted as a single element in the figure, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0038] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0039] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, and a secure digital (SD) memory card, among others. In other embodiments, the processor 118 may access information from and store data in a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0040] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel cadmium (NiCd), nickel zinc (NiZn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0041] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the 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 appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0042] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, module, FM radio unit, digital music player, media player, video game player module, Internet browser, virtual reality and / or augmented reality (VR / AR) device and activity tracker, etc. Peripheral device 138 may include one or more sensors, which may be one or more of the following: gyroscope, accelerometer, Hall effect sensor, magnetometer, orientation sensor, proximity sensor, temperature sensor, time sensor; geolocation sensor; altimeter, light sensor, touch sensor, magnetometer, barometer, gesture sensor, biometric sensor and / or humidity sensor.

[0043] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for both UL (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference via signal processing performed via hardware (e.g., a choke) or via a processor (e.g., a separate processor (not shown) or via the processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for both UL (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0044] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0045] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0046] Each of the evolved Node Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, and scheduling of users in the UL and / or DL, among other things. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0047] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as being part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than a CN operator.

[0048] The MME 162 may be connected to each of the evolved Node-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, and selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0049] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during an inter-evolved Node-B handover, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0050] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0051] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers.

[0052] Although the WTRU Figures 1A to 1D Although described as wireless terminals, it is contemplated that in certain representative embodiments, such terminals may (eg, temporarily or permanently) use a wired communications interface with a communications network.

[0053] In a representative embodiment, the other network 112 may be a WLAN.

[0054] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for a 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 to and / or out of the BSS. Traffic originating from outside the BSS and destined for the STA may be reached by the AP and may be delivered to the STA. Traffic originating from the STA and destined for a target outside the BSS may be transmitted to the AP to be delivered to the corresponding target. Traffic between STAs within the BSS may be transmitted by the AP, for example, wherein the source STA may transmit traffic to the AP, and the AP may deliver traffic to the target STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic may be transmitted between the source STA and the target STA (e.g., directly between them) using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (eg, all STAs in the STA) may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0055] When using the 802.11ac infrastructure operation mode or a similar operation mode, the AP may send beacons on a fixed channel (such as a primary channel). The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width dynamically set via signaling. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0056] High throughput (HT) STAs may communicate using a 40 MHz wide channel (eg, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels) to form a 40 MHz wide channel.

[0057] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and the data can be sent by sending STA. At the receiver of the receiving STA, the above-mentioned operation for 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0058] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may 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 for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0059] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may 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 may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (supporting (only supporting) a 1MHz operating mode) is sending to the AP, the entire available band may be considered busy even if most of the band remains idle and may be available.

[0060] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0061] Figure 1D1 is a system diagram illustrating the RAN 113 and the CN 115 in accordance with an embodiment. As noted above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0062] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 108b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send wireless signals to and / or receive wireless signals from the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, gNB 180a may transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In an embodiment, gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0063] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with parameter sets that may be scalable. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmit time intervals (TTIs) of varying or scalable lengths (e.g., containing different numbers of OFDM symbols and / or varying absolute time lengths over time).

[0064] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeB 160a, 160b, 160c may act as a mobility anchor for the WTRUs 102a, 102b, 102c, and the gNB 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0065] Each of the gNBs 180a, 180b, 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b and routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0066] 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 possible data networks (DNs) 185a, 185b. Although each of the foregoing elements is depicted as part of the CN 115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0067] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different PDU sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of NAS signaling, mobility management, etc. The AMF 182a, 182b may use network slicing in order to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced mobile broadband (eMBB) access, and / or services for machine type communication (MTC) access, etc. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0068] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 115 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 115 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0069] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, and providing mobility anchoring, etc.

[0070] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b via the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and the N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0071] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with reference to one or more of the following may be performed by one or more simulation devices (not shown): WTRU102a-d, base station 114a-b, evolved Node B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b and / or any other device described herein. The simulation device may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the simulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0072] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device may be directly coupled to another device for testing purposes and / or may use over-the-air wireless communications to perform testing.

[0073] 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 device can be used in a test scenario in a test laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via RF circuits (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0074] The present application discloses measurement-based carrier selection in a multi-carrier sidelink. The carrier selection may be applied to new radio (NR) vehicle-to-everything (V2X) communications. A wireless transmit and receive unit (WTRU) may be configured to select a carrier (e.g. Figure 2 ) and logical channel prioritization (LCP) prioritizing carriers with available sounding results from inter-UE coordination (IUC). The WTRU may be configured to identify a carrier and determine that the carrier has associated IUC information, which may include sounding measurement results. The WTRU may select the carrier from a plurality of carriers based on the carrier having the associated IUC information. In the selection based on the IUC information associated with the carrier, the WTRU may prefer the carrier over other carriers. The WTRU may associate a first CBR threshold with a carrier based on the IUC information associated with the carrier. The WTRU may select a logical channel and data for sending from the logical channel based on the first CBR threshold associated with the carrier.

[0075] The WTRU may receive data for transmission, wherein the data may have an associated data priority. In the event that the WTRU determines that the data priority is above a priority threshold and a first carrier is associated with the IUC information, the WTRU may determine that a first channel busy rate (CBR) associated with the first carrier satisfies a first CBR threshold and may determine that the first carrier is available for selection. In the event that the WTRU determines that the data priority is above the priority threshold and the second carrier is not associated with the IUC information, the WTRU may determine that a second CBR associated with the second carrier satisfies a second CBR threshold and may determine that the second carrier is available for selection. The first CBR threshold may be higher than the second CBR threshold. The WTRU may select a sidelink grant on the first carrier. In the event that the WTRU determines that the first CBR associated with the first carrier is higher than the second CBR threshold, the WTRU may select to send data associated with a data priority higher than the priority threshold on the first carrier. In the event that the WTRU determines that the first CBR associated with the first carrier is not higher than the second CBR threshold, the WTRU may select to send data from a highest priority channel on the first carrier. The WTRU may transmit the selected data using the sidelink grant on the first carrier.

[0076] Vehicular communication may be a communication mode by which WTRUs may communicate with each other (e.g., directly with each other). Two scenarios for V2X operation may include the following: an in-coverage scenario; and an out-of-coverage scenario. With respect to the in-coverage scenario, the WTRU may receive assistance from the network to start sending and receiving V2X messages. With respect to the out-of-coverage scenario, the WTRU may start sending and receiving V2X messages using preconfigured parameters.

[0077] V2X communications may be related to device-to-device (D2D) communications. V2X communication services may include the following types (e.g., four different types) (e.g., consisting of the following types): V2V (vehicle-to-vehicle); V2I (vehicle-to-infrastructure); V2N (vehicle-to-network); V2P (vehicle-to-pedestrian). V2V (vehicle-to-vehicle) communications may include vehicle WTRUs communicating with each other (e.g., directly communicating with each other). V2I (vehicle-to-infrastructure) communications may include vehicle WTRUs communicating with RSU / eNB. V2N (vehicle-to-network) communications may include vehicle WTRUs communicating with a core network. V2P (vehicle-to-pedestrian) communications may include vehicle WTRUs communicating with a WTRU that may be associated with a condition, such as a special condition, such as, for example, low battery capacity.

[0078] V2X communications may involve resource allocation. LTE may define two modes of operation in V2X communications. The first mode may be Mode 3, where the network may give the WTRU a scheduling assignment for V2X sidelink transmissions. The second mode may be Mode 4, where the WTRU may select (e.g., autonomously select) resources from a configured / preconfigured resource pool. V2X LTE may define two categories of resource pools. The first category may include a receive pool that may be monitored to receive V2X transmissions. The second category may include a V2X transmit pool that may be used by the WTRU to select transmit resources in Mode 4. A WTRU configured to be in Mode 3 may or may not use a transmit pool.

[0079] In LTE, the resource pool may be semi-statically signaled to the WTRU via RRC signaling. In Mode 4, the WTRU may use listening before selecting a resource from the RRC configured transmit pool. LTE V2X may or may not support dynamic resource pool reconfiguration; the pool configuration may, for example, be carried only via SIB and / or dedicated RRC signaling.

[0080] New Radio (NR) may provide V2X resource allocation. NR may have inherited two resource allocation modes from LTE. Mode 1 resource allocation may correspond to gNB scheduled resource allocation. Mode 2 resource allocation may correspond to WTRU autonomous resource allocation. The concept of resource pool and listening for Mode 2 resource allocation may also have been inherited from LTE.

[0081] Multi-carrier SL transmission may be provided. For V2X sidelink communication, carrier aggregation (CA) in the sidelink may be supported. It may be applied to both in-coverage WTRUs and out-of-coverage WTRUs. For CA in the sidelink, neither a primary component carrier nor a secondary component carrier may be defined. Each resource pool configured, e.g. (pre-)configured for V2X sidelink communication transmission or reception may be associated with a single carrier. If a WTRU supporting CA in the sidelink uses autonomous resource selection, it may perform carrier selection and may select one or more carriers for V2X sidelink communication transmission. Carrier selection may be performed at the MAC layer, depending on the configuration for V2X sidelink communication, e.g. the CBR of the (pre-)configured carrier and the PPPP of the V2X message to be sent. Carrier reselection may be performed when resource reselection may be triggered and may be triggered for each sidelink process. In order to avoid frequent switching across different carriers, the WTRU may continue to use a carrier that may have been selected for transmission if the CBR measured on this carrier may be below a (pre-)configured threshold. The selected carriers, e.g. all selected carriers may have the same synchronization reference or the same synchronization priority configuration. For a WTRU using autonomous resource selection, logical channel prioritization may be performed for sidelink resources on a carrier depending on the CBR measured on the carrier and the PPPP of the sidelink logical channel.

[0082] In LTE, carrier aggregation may be supported for broadcast, eg, broadcast-only.The transmitting WTRU may select the transmit carrier based on the carrier configured by upper layers for the service being transmitted (eg, L2 ID) and by taking into account the CBR to ensure equal resource usage.

[0083] The selection in LTE may or may not take into account some of the enhancements made for unicast and / or resource selection in NR. The TX WTRU may utilize (or rely on) IUC (inter-UE coordination) information when performing resource selection. The TX WTRU may not have access to IUC among all available carriers. For WTRUs that may not be able to perform listening in a carrier, the availability of IUC may be considered for carrier selection. The measurements available in unicast (SL CQI, SL RSRP) may be used to avoid selecting an inappropriate carrier for SL transmission.

[0084] Configurations for SL carrier aggregation may be provided. Carrier selection may be performed by the SL WTRU. The WTRU may adopt criteria for carrier selection. The WTRU in Mode 2 may perform a carrier selection process. Carrier selection may include determining allowable carriers for sending a specific or multiple L2 IDs. The WTRU may determine the actual carrier used to send a specific or multiple L2 IDs at a given time. The WTRU may select the actual carrier for transmission from a set of allowable carriers. The selection of carriers may include determining specific carriers that can be used for unicast and carriers that can be used for broadcast / multicast. The selection may also include determining the amount of time that one or more carriers can be used for transmission, and selecting a set of carriers (e.g., a preferred set of carriers) to be transmitted to a peer WTRU (e.g., in a unicast link).

[0085] A WTRU in Mode 2 may select a carrier for SL transmission using one or a combination of the following criteria: L2ID; CBR; QoS and / or SLRB configuration; SL measurements reported by a peer WTRU; availability and / or nature of sensing results that may come from IUC information; licensed carriers versus unlicensed carriers; LBT results on unlicensed carriers; broadcast type; HARQ feedback; presence of PSFCH on a carrier; and / or presence of one or more resource pools configured on a carrier that meet pool-specific criteria. In conjunction with L2ID, the WTRU may determine whether use of L2ID on a carrier is allowed based on information from upper layers.

[0086] The CBR may be used as a criterion for selecting a carrier for SL transmission. The WTRU may determine whether a carrier may be allowed for transmission based on whether the measured CBR is above a threshold that depends on priority. The WTRU may determine a specific carrier to be used for transmission by selecting (e.g., selecting first) a carrier with a specific CBR, such as, for example, the lowest CBR or the highest CBR. The condition for carrier selection may use CBR in combination with other factors. The WTRU may use one factor for selection under a first CBR condition and another factor for selection under a second CBR condition. The WTRU may determine a CBR threshold for selection based on the result of another condition, for example, determining the number of carriers to be selected based on the CBR.

[0087] QoS and / or SLRB configuration may be used as criteria for selecting a carrier for SL transmission. The WTRU may determine the CBR threshold for determining the allowed carriers based on the priority of the data available for transmission. The specific carriers, the number of allowed carriers, the allowable CBR range for selection, the time period that the carrier can be maintained before triggering reselection, etc. may be configured in the SLRB configuration, or may be determined based on parameters associated with the SLRB configuration or the QoS flow mapped to the SLRB. Whether the criteria for selection (e.g., the availability of listening results from the IUC) are applied may depend on the priority associated with the data available for transmission.

[0088] SL measurements reported by a peer WTRU may be used as criteria for selecting a carrier for SL transmission. SL measurements may include measurements received (e.g., currently received) from a peer WTRU, such as, for example, SL RSRP, SL CQI, and other measurements that may be considered in the future. The WTRU may select the carrier with the highest SL RSRP from the set of allowed carriers. If the carrier may currently be used for unicast and the reported SL RSRP may be above a threshold, the carrier may be maintained regardless of the CBR measured on the carrier. If the carrier may currently be used for unicast and the reported SL RSRP may be above a threshold, it may be determined whether the carrier may be an allowed carrier by a different threshold than a carrier that may not be used for unicast or may not have a reported SL RSRP above a threshold.

[0089] The availability and / or nature of the sensing results, which may come from the IUC information, may be used as a criterion for selecting a carrier for SL transmission. The WTRU may select a carrier based on whether sensing results are available, where such sensing results may be obtained through the WTRU's own sensing, or may be obtained from sensing performed by other WTRUs (and conveyed in the IUC information). The WTRU may select a carrier based on the nature of the available listening results, such as, for example, the following: whether the listening results may be associated with partial listening, short-term partial listening, periodic partial listening, full listening, etc., or other types of listening that may represent the amount of resources listened to; whether the listening may be generated by the WTRU itself, or received from another WTRU in an IUC information; whether the listening results received from the IUC information may be received as a result of a request, or as a result of a peer WTRU autonomously sending the results; whether the listening results may be associated with preferred resources, non-preferred resources, or resources that may cause conflicts (e.g., the type of IUC information transmitted); the number of WTRUs from which the TX WTRU may receive IUC information that may be associated with a particular carrier; whether the IUC information may be received from a WTRU with which the TX WTRU may have a unicast link; and / or whether the IUC information may be received from a WTRU to which the TX WTRU may send (possibly as a result of carrier selection) or to which the TX WTRU is selecting a carrier to send to.

[0090] Licensed carriers versus unlicensed carriers may be used as criteria for selecting a carrier for SL transmission. The WTRU may select a licensed carrier before an unlicensed carrier. If a first condition may be met (e.g., the CBR may be above a first threshold), the WTRU may select a licensed carrier based on the criteria, and if a second condition may be met (e.g., the CBR may be above a second threshold), the WTRU may select a licensed carrier based on the same or different criteria. The WTRU may select a licensed carrier before an unlicensed carrier (or vice versa) based on whether some other conditions / criteria may be met (e.g., based on priorities configured in one or more SLRBs, based on whether the SLRBs are configured to take precedence over licensed or unlicensed, etc.).

[0091] The LBT results on the unlicensed carrier may be used as a criterion for selecting a carrier for SL transmission. If LBT fails on a carrier, fails multiple times, and / or fails within a period of time, the WTRU may exclude the carrier from selection. The WTRU may select a carrier based on the number of LBT failures that may occur on a carrier within a period of time.

[0092] The broadcast type may be used as a criterion for selecting a carrier for SL transmission. The WTRU may use a first criterion or condition associated with the criterion to determine the carrier to select when data is available for the first broadcast type, and may use a second criterion or condition associated with the criterion to determine the carrier to select when data is available for the second broadcast type.

[0093] HARQ feedback may be used as a criterion for selecting a carrier for SL transmission. The WTRU may select a carrier based on the ratio of ACK / NACKs received on the carrier that may be associated with a particular destination. If the WTRU may receive (e.g., continuously and / or over a period of time) multiple NACKs associated with an L2 ID on a carrier, it may select another carrier that may be used for that particular L2 ID. The WTRU may exclude a carrier from selection after, for example, receiving multiple NACK / DTXs continuously and / or over a period of time. This exclusion may be maintained for a period of time.

[0094] The presence of PSFCH on a carrier may be used to select a carrier for SL transmission. If the WTRU may be configured with a unicast link and / or multicast with HARQ feedback, or if the WTRU may have a logical channel configured with enabled HARQ feedback, the WTRU may select or prioritize a carrier with configured PSFCH resources.

[0095] The presence of one or more resource pools configured on a carrier that meet pool-specific criteria may be used to select a carrier for SL transmission. If at least one pool or all pools on a carrier meet the criteria, the carrier may be selected / prioritized.

[0096] The criteria described herein, as well as other criteria, may be used to prioritize certain carriers over other carriers, perhaps in a selection triggered by the availability of data for a particular destination, bearer, priority, etc. In the context of carrier selection, prioritization may consist of one or more of the following: the WTRU may select a priority carrier over a non-priority carrier if the selection criteria are the same; the WTRU may use more relaxed conditions (e.g., a higher CBR threshold) when determining whether to exclude a carrier from the allowed carrier set, the selected carrier set, or a carrier for transmission; the WTRU may include more carriers than the maximum allowable number of carriers in its selected carrier list if carriers may be prioritized; the WTRU may select (e.g., may select first) a priority carrier during carrier selection (perhaps in an order defined by another criterion) before the WTRU considers non-priority carriers for selection. Example implementations of the above criteria used in prioritization during carrier selection may be discussed herein.

[0097] The use of a carrier in a unicast link may result in prioritization of that carrier. The WTRU may prioritize carriers that have been determined to be used, may be used, or have been used in a unicast link to communicate with a peer WTRU. A benefit of this may be that it may avoid the need for reconfiguration of the peer WTRU, which may involve PC5-RRC signaling, and may also have an impact on the carrier selection of the WTRU.

[0098] The quality measured by a peer WTRU on a carrier in a unicast link may result in prioritization of that carrier. The WTRU may prioritize carriers on which the WTRU may have received measurements (e.g., CQI) from a peer WTRU, possibly where such measurements meet a criterion (e.g., the measurements may be above a threshold). The WTRU may prioritize carriers where the number of reports or the number of WTRUs reporting on the carrier (which may meet the measurement criterion) may be above a certain number. A benefit of this may be that it may allow for more efficient use of SL resources on carriers with higher CBRs.

[0099] The availability of sensed results received from IUC information for a carrier may result in prioritization of that carrier. The WTRU may prioritize carriers where the WTRU may have received IUC information from another WTRU, may have recently received IUC information from another WTRU, and / or may have requested IUC information from another WTRU. The WTRU may be configured with a validity timer associated with the received IUC information and may prioritize carriers where the WTRU may have valid IUC information associated with that carrier at resource selection. The benefit of such processing may be that it may reduce overall conflicts on the sidelink by prioritizing the use of carriers where sensed results may be applied.

[0100] The selection or removal of a carrier may be inhibited for a period of time. It is possible that after the carrier selection process, the selection of a carrier or the removal of a carrier may be inhibited for a period of time. After one of the triggers / conditions for selecting a carrier (e.g., HARQ NACK), the WTRU may maintain the selected carrier for at least a period of time. Such maintenance may also be dependent on other criteria in this document being met throughout the period of time. Similarly, after excluding a carrier from carrier selection, the WTRU may continue to exclude the carrier for a period of time.

[0101] Selection and / or reselection of a carrier may be triggered. The WTRU may trigger a carrier (re)selection procedure at one or more of any combination of the following events (e.g., A as a condition for B, etc.): events related to IUC; events related to receiving measurements from a peer WTRU; events related to unicast link establishment / maintenance; events related to HARQ feedback; events related to establishment / release of new QoS flows and / or SLRBs; events related to unlicensed operation; events related to a change in CBR; and events related to a change in SL DRX configuration or Uu DRX configuration.

[0102] Events related to IUC may be used to trigger carrier selection and / or reselection. When the WTRU receives an IUC that may be related to a carrier that is currently being used, the WTRU may trigger carrier (re)selection. When the received IUC may be associated with a carrier for which the WTRU may not have IUC information, the WTRU may trigger carrier (re)selection. When the validity of IUC information that may be associated with a carrier has expired, the WTRU may trigger carrier (re)selection. When the WTRU does not receive IUC information for a carrier (possibly when a timer associated with the validity expires), the WTRU may trigger carrier (re)selection.

[0103] Related to receiving measurements (e.g., CQI, RSRP) from a peer WTRU, events that may be associated with some conditions on these measurements may be used to trigger carrier (re)selection. When the WTRU receives a CQI report from a peer WTRU that may have a CQI value above or below a threshold, the WTRU may trigger carrier (re)selection.

[0104] Events related to unicast link establishment / maintenance may be used to trigger carrier (re)selection. The WTRU may trigger carrier (re)selection after establishing or releasing a unicast link with a peer WTRU. The WTRU may trigger carrier (re)selection after receiving a sidelink reconfiguration message from a peer WTRU, thereby possibly (re)configuring a set of carriers. The WTRU may trigger carrier (re)selection after successfully applying a sidelink reconfiguration received from a peer WTRU. The WTRU may trigger carrier (re)selection after sending / receiving a reconfiguration success / failure message. The WTRU may trigger carrier selection (re)selection after detecting SL-RLF with a peer WTRU.

[0105] Events related to HARQ feedback may be used to trigger carrier (re)selection.A WTRU may trigger carrier (re)selection after receiving (possibly continuously and / or possibly occurring over a period of time) one or more of a HARQ NACK and / or a HARQ DTX from a peer WTRU.

[0106] Events related to the establishment / release of new QoS flows and / or SLRBs may be used to trigger carrier (re)selection. If such establishment / release may result in a change in the selected carrier based on the carrier selection criteria herein, the WTRU may trigger carrier (re)selection after establishing a new SLRB.

[0107] Events related to unlicensed operation may be used to trigger carrier (re)selection.The WTRU may trigger carrier (re)selection after one or more LBT failures on a carrier.

[0108] Events related to changes in CBR may be used to trigger carrier (re)selection.The WTRU may trigger carrier (re)selection after the measured CBR for a particular carrier changes by a certain amount.

[0109] Events related to changes in SL DRX configuration or Uu DRX configuration may be used to trigger carrier (re)selection. The WTRU may trigger carrier (re)selection after the SL DRX configuration may have changed between two WTRUs.

[0110] The LCP may take into account criteria for carrier selection. The WTRU may be configured with LCP restrictions associated with the mapping of data on a logical channel to a particular carrier. The conditions associated with applying such LCP restrictions may be related to the criteria applied for carrier selection. For example, if a carrier may have been selected due to the presence of data available from a particular logical channel, a grant on that carrier may be used, for example, only for that logical channel. If the conditions for selecting a carrier have been met for carrier selection due to the presence of data from a logical channel, the WTRU may multiplex the data associated with that logical channel (e.g., only data) onto the grant associated with the selected carrier. If the WTRU prioritizes one carrier over another for a particular logical channel, the data from that particular logical channel (e.g., only data) may be mapped to the priority carrier. If the conditions for selecting a carrier have been met for carrier selection due to the presence of data from a logical channel, the WTRU may multiplex the data associated with that logical channel (e.g., only data) onto the grant if the carrier meets the same conditions. If the condition for carrier selection may have been met due to the presence of data from a logical channel and may not have been met if there is no data on the logical channel, if the carrier may have met the condition for the presence of the logical channel and may not meet the condition for the absence of the logical channel, the WTRU may (e.g., may only) multiplex data associated with the logical channel onto the carrier.

[0111] If the WTRU may have data available for the SLRB with a priority higher than a priority threshold, the WTRU may use a first CBR threshold (e.g., a carrier may be selected if the measured CBR is below the first threshold) for carriers where the WTRU may have a sensed result from another WTRU, and may use a second CBR threshold (e.g., a carrier may be selected if the measured CBR is below the second threshold) for carriers where the WTRU may not have a sensed result from another WTRU, e.g. Figure 2 In this case, when the WTRU selects / receives a grant associated with a carrier having a CBR that may be below a first threshold but above a second threshold, the WTRU may multiplex data (e.g., only data) associated with a logical channel with a priority above the priority threshold.

[0112] A wireless transmit and receive unit (WTRU) may include a processor configured to: identify a first carrier among a plurality of carriers; determine that inter-UE coordination (IUC) information is associated with the first carrier; and select the first carrier from the plurality of carriers based on the IUC information. The processor configured to select the first carrier from the plurality of carriers based on the IUC information may be configured to prioritize the carrier based on the IUC information. The processor may also be configured to: determine a second carrier among the plurality of carriers; receive data, the data having an associated priority; and, conditional on the associated priority being higher than a threshold, associate a first CBR threshold with the first carrier based on the IUC associated with the first carrier; and associate a second CBR threshold with the second carrier. The first CBR threshold may be higher than the second CBR threshold. The processor configured to select the first carrier from the plurality of carriers may be configured to select the first carrier based on the IUC information and the first CBR threshold. The processor may also be configured to: select a sidelink grant on the first carrier; select data having a priority based on the first CBR threshold associated with the first carrier; and transmit the data on the first carrier.

[0113] If the WTRU may use a carrier to send unicast data, the WTRU may use a first CBR threshold to select a carrier, otherwise a second CBR threshold may be used. If the WTRU selects a grant on a carrier where the CBR on the carrier meets the selection criteria in the unicast case, but does not meet the selection criteria in the broadcast / multicast case, the WTRU may select unicast data to send on the grant / carrier. If both unicast and multicast criteria are met on the carrier, the WTRU may not apply LCP restrictions.

[0114] A WTRU in unicast may select or be assigned a primary carrier. When multiple carriers are configured / used between WTRUs, a WTRU with a unicast link may select or be assigned (e.g., by a peer WTRU, by the network, etc.) a primary carrier. The WTRU may use the criteria herein to select a primary carrier from a set of carriers used to send data on a unicast link. For example, the WTRU may select the carrier with the smallest CBR as the primary carrier. The WTRU may select the carrier with the best CQI as the primary carrier. The WTRU may select the carrier with the largest number of sensed results received from other WTRUs.

[0115] The WTRU may use the primary carrier to perform, for example, the following operations associated with a unicast link: sending PC5-RRC signaling; sending PC5-S signaling; using the primary carrier when a situation occurs where a single carrier (e.g., only a single carrier) can be used (e.g., the average CBR over all carriers is above a threshold); the WTRU may use the CBR of the primary carrier as a representation of the CBR of the carrier associated with the unicast link; the sending of IUC information may be performed on the primary carrier; and / or the IUC information may be provided to a peer WTRU for the primary carrier.

[0116] The WTRU may use the same carrier as its primary carrier that a peer WTRU may use. The WTRU may be assigned a primary carrier by a peer WTRU. The WTRU may (re)select a primary carrier when the WTRU performs a carrier (re)selection procedure. The WTRU may (e.g., may alternatively) be configured with a separate trigger (e.g., different from carrier (re)selection) for determining the primary carrier.

[0117] Although the features and elements described herein are described in particular combinations, each feature or element may be used alone without the other features and elements of the preferred embodiments, or in various combinations with or without the other features and elements.

[0118] The description herein is provided for exemplary purposes and does not in any way limit the applicability of the described systems, methods, and means to other wireless technologies and / or wireless technologies using different principles where applicable. The term network in the present disclosure may refer to one or more gNBs (which in turn may be associated with one or more transmit / receive points (TRPs)), or may refer to any other node in a radio access network.

[0119] Although the implementation described herein may consider 3GPP specific protocols, it should be understood that the implementation described herein is not limited to such scenarios and is applicable to other wireless systems. For example, although the solution described herein considers LTE, LTE-A, New Radio (NR) or 5G specific protocols, it should be understood that the solution described herein is not limited to such scenarios and is also applicable to other wireless systems.

[0120] The processes described herein may be implemented in a computer program, software, and / or firmware incorporated in a computer-readable medium for execution by a computer and / or processor. Examples of computer-readable media include, but are not limited to, electronic signals (sent via wired and / or wireless connections) and / or 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, but not limited to, built-in hard disks and removable disks), magneto-optical media, and / or optical media (such as compact disk (CD)-ROM disks and / or digital versatile disks (DVDs)). A processor associated with the software may be used to implement a radio frequency transceiver for a WTRU, a terminal, a base station, an RNC, and / or any host computer.

Claims

1. A wireless transmit and receive unit (WTRU), the wireless transmit and receive unit (WTRU) comprising: A processor, the processor being configured to: receiving data, the data having an associated data priority; On the condition that the data priority is higher than the priority threshold and the first carrier is associated with inter-UE coordination (IUC) information: determining that a first channel busy rate (CBR) associated with the first carrier satisfies a first CBR threshold, and Determining that the first carrier is available for selection; and On the condition that the data priority is higher than the priority threshold and the second carrier is not associated with the IUC information: determining that a second CBR associated with the second carrier satisfies a second CBR threshold, and It is determined that the second carrier is available for selection.

2. The WTRU of claim 1 , wherein the first CBR threshold is higher than the second CBR threshold.

3. The WTRU of claim 1 or 2, The processor is further configured to: selecting a sidelink grant on the first carrier; and Data associated with a data priority above the priority threshold is selected to be transmitted on the first carrier.

4. The WTRU of claim 3, wherein the processor is further configured to: The data associated with a data priority above the priority threshold is transmitted using the sidelink grant on the first carrier.

5. The WTRU of claim 3, The processor is further configured to: Data from a highest priority logical channel is selected to be sent on the first carrier, conditional upon the first CBR associated with the first carrier being not higher than the second CBR threshold.

6. The WTRU of any one of claims 1 to 5, wherein the processor is further configured to receive the IUC information from a second WTRU.

7. The WTRU of claim 6, wherein the processor is further configured to determine that the IUC information is received within a specified time period.

8. The WTRU of claim 7, wherein the processor is further configured to request the IUC information from the second WTRU.

9. The WTRU according to any one of claims 1 to 8, The processor is further configured to: determining a third carrier associated with the IUC information; receiving second data, the second data having an associated second data priority; and Under the condition that the second data priority is lower than the priority threshold, determining that the third carrier is selectable based on a third CBR associated with the third carrier satisfying the second CBR threshold.

10. The WTRU according to any one of claims 1 to 9, The processor is further configured to: determining that the fourth carrier is not associated with the IUC information; receiving third data, the third data having an associated third data priority; and Under the condition that the third data priority is lower than the priority threshold, determining that the fourth carrier is selectable based on that a fourth CBR associated with the fourth carrier meets the second CBR threshold.

11. A method for carrier selection, the method comprising: receiving data, the data having an associated data priority; On the condition that the data priority is higher than the priority threshold and the first carrier is associated with inter-UE coordination (IUC) information: determining that a first channel busy rate (CBR) associated with the first carrier satisfies a first CBR threshold, and Determining that the first carrier is available for selection; and On the condition that the data priority is higher than the priority threshold and the second carrier is not associated with the IUC information: determining that a second CBR associated with the second carrier satisfies a second CBR threshold, and It is determined that the second carrier is available for selection. The method of claim 11 , wherein the first CBR threshold is higher than the second CBR threshold.

13. The method according to claim 11 or 12, further comprising: selecting a sidelink grant on the first carrier; as well as Data associated with a data priority above the priority threshold is selected to be transmitted on the first carrier.

14. The method of claim 13, further comprising transmitting the data associated with a data priority above the priority threshold using the sidelink grant on the first carrier.

15. The method according to claim 13, The processor is further configured to: Data from a highest priority logical channel is selected to be sent on the first carrier, conditional upon the first CBR associated with the first carrier being not higher than the second CBR threshold.

16. The method according to any one of claims 11 to 15, further comprising: receiving the IUC information from a second WTRU; as well as It is determined that the IUC information is received within a prescribed time period of the current time.

17. A wireless transmit and receive unit (WTRU), the wireless transmit and receive unit (WTRU) comprising: A processor, the processor being configured to: receiving data, the data having an associated data priority; On the condition that the data priority is higher than the priority threshold and the first carrier is associated with inter-UE coordination (IUC) information: determining that a first channel busy rate (CBR) associated with the first carrier satisfies a first CBR threshold, and Determining that the first carrier is available for selection; selecting a sidelink grant on the first carrier; and Data associated with a data priority above the priority threshold is selected to be transmitted on the first carrier.

18. The WTRU of claim 17 wherein the processor is further configured to: The data associated with a data priority above the priority threshold is transmitted using the sidelink grant on the first carrier.

19. The WTRU of claim 17 or 18, wherein the processor is further configured to receive the IUC information from a second WTRU.

20. The WTRU of claim 19, wherein the processor is further configured to determine that the IUC information is received within a specified time period.

21. The WTRU of claim 19, wherein the processor is further configured to request the IUC information from the second WTRU.

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