Wireless transmitting and receiving unit and method implemented by the wireless transmitting and receiving unit

Abstract

As disclosed herein, there are systems, devices, and / or methods that address, but are not limited to, one or more of the following: a radio transmit / receive unit (WTRU) configured to transmit sidelink radio link measurements to a base station (e.g., a gNB); a WTRU configured to consider CBR / CR levels for initiating measurements on neighboring links / cells; a WTRU configured to consider CBR / CR levels in conjunction with SL RSRP / RSRQ / RSNI thresholds for reporting measurements; a WTRU configured to report sidelink measurements differently based on usage data or discovery signals; a relay WTRU configured to forward / report sidelink measurements to a gNB; and handover commands based on measurements at a remote WTRU in a relay scenario.

Description

[0001] This application is a divisional application of the invention patent application filed on January 12, 2022, with application number 202280015088.7 and invention title "Method for Relay Measurement".

[0002] Cross-references to related applications

[0003] This application claims the benefit of U.S. Provisional Application No. 63 / 136,510, filed January 12, 2021, the contents of which are incorporated herein by reference. Background Technology

[0004] Generally, as use cases and performance requirements change, there is a need to improve systems, devices, and methods related to wireless communication. For example, there is a need to address issues related to device-to-network and device-to-device coverage extension. Summary of the Invention

[0005] As disclosed herein, there are systems, devices, and / or methods that address, but are not limited to, one or more of the following: a radio transmit / receive unit (WTRU) configured to transmit sidelink radio link measurements to a base station (e.g., a gNB); a WTRU configured to consider CBR / CR levels for initiating measurements on neighboring links / cells; a WTRU configured to consider CBR / CR levels in conjunction with SL RSRP / RSRQ / RSNI thresholds for reporting measurements; a WTRU configured to report sidelink measurements differently based on usage data or discovery signals; a relay WTRU configured to forward / report sidelink measurements to a gNB; and handover commands based on measurements at a remote WTRU in a relay scenario. Attached Figure Description

[0006] A more detailed understanding can be obtained from the following description given by way of example in conjunction with the accompanying drawings, wherein similar reference numerals in the drawings indicate similar elements, and wherein:

[0007] Figure 1A This is a system diagram illustrating an exemplary communication system that can be implemented in one or more of the disclosed embodiments;

[0008] Figure 1B This illustrates that, according to one implementation scheme, it is possible to Figure 1A A system diagram of an exemplary wireless transmit / receive unit (WTRU) used within the communication system shown;

[0009] Figure 1C This illustrates that, according to one implementation scheme, it is possible to Figure 1A A system diagram of an exemplary radio access network (RAN) and an exemplary core network (CN) used within the communication system shown;

[0010] Figure 1D This illustrates that, according to one implementation scheme, it is possible to Figure 1A A system diagram of another exemplary RAN and another exemplary CN used in the communication system shown;

[0011] Figure 2 An example of a user plane radio protocol stack for WTRU to NW relay (e.g., PC5) for Layer 2 evolution is shown;

[0012] Figure 3 An example of a control plane radio protocol stack for a WTRU to NW relay (e.g., PC5) used for Layer 2 evolution is shown;

[0013] Figure 4 An example of a user plane stack for an NR L2 WTRU to NW relay (without an adaptation layer at PC5) is shown.

[0014] Figure 5 An example of a control plane protocol stack for L2 WTRU to NW relay (without an adaptation layer at PC5) is shown;

[0015] Figure 6 An example of a user plane protocol stack for L2 WTRU to NW relay (with adaptation layer support at PC5 interface) is shown;

[0016] Figure 7 An example of a control plane protocol stack for L2 WTRU to NW relay (with adaptation layer support at PC5 interface) is shown;

[0017] Figure 8 An example of the procedure for remote WTRU handover to a direct Uu cell (e.g., handover from an indirect path to a direct path) is shown;

[0018] Figure 9 An example of the procedure for switching from a remote WTRU to an indirect relay WTRU is shown;

[0019] Figure 10 An exemplary procedure for establishing a remote WTRU connection is shown;

[0020] Figure 11 An example of an advanced measurement model is shown;

[0021] Figure 12 An example of a WTRU-to-WTRU relay is shown;

[0022] Figure 13 An example of a WTRU to NW relay is shown;

[0023] Figure 14An example of a WTRU relay environment capable of performing measurements / reporting is shown;

[0024] Figure 15 An example of a measurement / reporting method is shown;

[0025] Figure 16 An example of a measurement / reporting method is shown; and

[0026] Figure 17 An example of a measurement / reporting method is shown. Detailed Implementation

[0027] Figure 1A This is a schematic diagram illustrating an exemplary communication system 100 that can be implemented in one or more of the disclosed embodiments. Communication system 100 can be a multiple access system providing content such as voice, data, video, messaging, and broadcasting to multiple wireless users. Communication system 100 enables multiple wireless users to access such content through the sharing of system resources (including wireless bandwidth). For example, 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 Extended OFDM (ZT-UW-DFT-S-OFDM), Unique Word OFDM (UW-OFDM), Resource Block Filtered OFDM, Filter Bank Multicarrier (FBMC), etc.

[0028] like Figure 1AAs shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112. However, 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, and 102d can be any type of device configured to operate and / or communicate in a wireless environment. For example, WTRUs 102a, 102b, 102c, and 102d (any of which may be referred to as a station (STA)) may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile user 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 environments), 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.

[0029] 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, Internet 110, and / or other networks 112). By way of example, base stations 114a and 114b may be base transceiver stations (BTS), Node Bs, evolved Node Bs (eNBs), home Node Bs, home evolved Node Bs, next-generation Node Bs, such as gNode Bs (gNBs), New Radio (NR) Node Bs, site controllers, access points (APs), wireless routers, etc.; furthermore, as discussed herein, references to base stations may refer to any of the foregoing examples, and it is also intended that references to any particular example in a particular example may be interchangeable with the more general concept of a base station. Although base stations 114a and 114b are each depicted as a single element, it should be understood that base stations 114a and 114b may include any number of interconnected base stations and / or network elements.

[0030] Base station 114a may be part of RAN 104, 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 of radio services to a specific geographic area, which may be relatively fixed or changeable 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 an 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 transmit and / or receive signals in desired spatial directions.

[0031] 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, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). Any suitable radio access technology (RAT) can be used to establish air interface 116.

[0032] 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, SC-FDMA, etc. For example, base stations 114a and WTRUs 102a, 102b, and 102c in RAN 104 may implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may 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 (DL) Packet Access (HSDPA) and / or High-Speed ​​Uplink (UL) Packet Access (HSUPA).

[0033] In the implementation scheme, 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.

[0034] In one implementation, base station 114a and WTRUs 102a, 102b, 102c can enable radio technologies such as NR radio access, which can use NR to establish air interface 116.

[0035] In the implementation scheme, 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, for example, use a dual connectivity (DC) principle to implement both LTE and NR radio access together. 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).

[0036] In other implementations, base station 114a and WTRUs 102a, 102b, and 102c can implement 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), GSM Enhanced Data Rate Evolution (EDGE), and GSM EDGE (GERAN).

[0037] Figure 1ABase station 114b can be, for example, a wireless router, a home node B, a home evolution node B, or an access point, and can utilize any suitable RAT to facilitate wireless connectivity in localized areas such as commercial locations, homes, vehicles, campuses, industrial facilities, air corridors (e.g., for use by drones), roads, 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 another 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 cellular-based RATs (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish picocells or femtocells. 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.

[0038] RAN 104 can communicate with CN 106, 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 can 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 can provide call control, billing services, location-based services, prepaid calling, internet connectivity, video distribution, etc., and / or perform advanced security functions such as user authentication. Although not explicitly stated... Figure 1A As shown, but it should be understood that RAN 104 and / or CN 106 can communicate directly or indirectly with other RANs that use the same RAT as RAN 104 or a different RAT. For example, in addition to being connected to RAN 104 which can utilize NR radio technology, CN 106 can also communicate with another RAN (not shown) that uses GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0039] CN 106 may also act as a gateway for WTRUs 102a, 102b, 102c, and 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 or a different RAT.

[0040] Some or all of the WTRUs 102a, 102b, 102c, and 102d in the 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 employ cellular-based radio technology and with a base station 114b that can employ IEEE 802 radio technology.

[0041] Figure 1B This is a system diagram illustrating an exemplary WTRU 102. (See diagram below.) Figure 1B As shown, WTRU 102 may include a processor 118, a transceiver 120, a transmitting / receiving 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 peripheral devices 138, etc. It should be understood that, while remaining consistent with the implementation, WTRU 102 may include any sub-combination of the foregoing elements.

[0042] Processor 118 can 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), any other type of integrated circuit (IC), a state machine, etc. Processor 118 can 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 can be coupled to transceiver 120, which can be coupled to transmitting / receiving element 122. Although Figure 1B The processor 118 and transceiver 120 are depicted as separate components, but it should be understood that the processor 118 and transceiver 120 may be integrated together in an electronic package or chip.

[0043] Transmitting / receiving element 122 may 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 may be an antenna configured to transmit and / or receive RF signals. In another embodiment, transmitting / receiving element 122 may 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 may be configured to transmit and / or receive both RF and optical signals. It should be understood that transmitting / receiving element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0044] 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. Therefore, 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.

[0045] Transceiver 120 can be configured to modulate signals transmitted by transmitting / receiving element 122 and demodulate signals received by transmitting / receiving element 122. As noted above, WTRU 102 may have multi-mode capability. For example, transceiver 120 may therefore include multiple transceivers to enable WTRU 102 to communicate via various RATs (such as NR and IEEE 802.11).

[0046] The processor 118 of WTRU 102 may be coupled to a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) unit or an organic light-emitting diode (OLED) display unit) and may receive user input data therefrom. The processor 118 may also output user data to the speaker / microphone 124, keypad 126, and / or display / touchpad 128. Furthermore, the processor 118 may access information from any type of suitable memory (such as non-removable memory 130 and / or removable memory 132) and store data in any type of suitable memory. Non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. Removable memory 132 may include a user identity module (SIM) card, memory stick, secure digital storage (SD) card, etc. In other embodiments, the 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.

[0047] The processor 118 may receive power from the power supply 134 and may be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 may be any suitable device for powering the WTRU 102. For example, the power supply 134 may include one or more dry cell battery packs (e.g., nickel-cadmium (NiCad), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0048] 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 the 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 should be understood that, while remaining consistent with the implementation, the WTRU 102 may acquire location information using any suitable location determination method.

[0049] The processor 118 may also be coupled to other peripheral devices 138, which may include one or more software and / or hardware modules providing additional features, functions, and / or wired or wireless connectivity. For example, peripheral device 138 may include an accelerometer, electronic compass, satellite transceiver, digital camera (for photos and / or video), Universal Serial Bus (USB) port, vibration device, television transceiver, hands-free headset, etc. 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. Peripheral devices 138 may include one or more sensors. Sensors 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, humidity sensors, etc.

[0050] 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 UL (e.g., for transmission) and DL (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 through signal processing via hardware (e.g., a choke) or via a processor (e.g., a separate processor (not shown) or via processor 118). In an 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 UL (e.g., for transmission) or DL ​​(e.g., for reception)) are concurrent.

[0051] Figure 1C This is a system diagram illustrating RAN 104 and CN 106 according to an implementation scheme. As described above, RAN 104 can communicate with WTRUs 102a, 102b, and 102c via air interface 116 using E-UTRA radio technology. RAN 104 can also communicate with CN 106.

[0052] RAN 104 may include evolved Node Bs 160a, 160b, and 160c; however, it should be understood that RAN 104 may include any number of evolved Node Bs while remaining consistent with the implementation scheme. Each evolved Node B 160a, 160b, and 160c may include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In the implementation scheme, evolved Node Bs 160a, 160b, and 160c may implement MIMO technology. Therefore, evolved Node B 160a may, for example, use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a.

[0053] Each of the evolved nodes 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 UL and / or DL, etc. Figure 1C As shown, evolution nodes B 160a, 160b, and 160c can communicate with each other via the X2 interface.

[0054] 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 (PGW) 166. Although the foregoing elements are depicted as 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 the CN operator.

[0055] The MME 162 can connect to each of the evolved nodes B 162a, 162b, and 162c in RAN 104 via the S1 interface and can be used 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 RAN 104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0056] The SGW 164 can connect to each of the evolved Nodes B 160a, 160b, and 160c in RAN 104 via the S1 interface. The SGW 164 typically routes and forwards user data packets to and from WTRUs 102a, 102b, and 102c. The SGW 164 can perform other functions such as anchoring the user plane during inter-evolved Node B handovers, 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.

[0057] SGW 164 can be connected to PGW 166, which provides 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.

[0058] CN 106 can facilitate 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 traditional landline communication equipment. For example, CN 106 may include an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between CN 106 and PSTN 108, or be able to communicate with such an IP gateway. 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.

[0059] Despite WTRU in Figures 1A to 1D While described as a wireless terminal, it is conceivable that in some representative implementations, such a terminal may (e.g., temporarily or permanently) use a wired communication interface with a communication network.

[0060] In a representative implementation, the other network 112 may be a WLAN.

[0061] A WLAN in Infrastructure Basic Services Set (BSS) mode may have an access point (AP) for the BSS and one or more sites (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 carries traffic out of the BSS. Traffic originating outside the BSS and destined for a STA can reach and be delivered to the STA via the AP. Traffic originating from a STA and destined for 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 point-to-point traffic. Point-to-point traffic can be sent between source and destination STAs (e.g., directly between them) using Direct Link Establishment (DLS). In some representative implementations, the DLS may use 802.11e DLS or 802.11z Tunneled DLS (TDLS). WLANs using the Standalone BSS (IBSS) mode may not have an access point (AP), and STAs within the IBSS or using the IBSS (e.g., all STAs) can communicate directly with each other. The IBSS communication mode may sometimes be referred to as the "ad-hoc" communication mode in this document.

[0062] When operating in 802.11ac infrastructure mode or a similar mode, the AP can transmit beacons on a fixed channel, such as the primary channel. The primary channel can be of fixed width (e.g., a 20 MHz wide bandwidth) or dynamically configured. The primary channel can be the operating channel of the BSS and can be used by the STA to establish a connection with the AP. In some representative implementations, Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) can be implemented, for example, in an 802.11 system. For CSMA / CA, each STA (including the AP) can listen to the primary channel. If the primary channel is listened to / detected and / or determined to be busy by a particular STA, that STA can back off. A single STA (e.g., only one station) can transmit at any given time within a given BSS.

[0063] 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.

[0064] The Very High Throughput (VHT) STA supports 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 (this can be referred to as an 80+80 configuration). For the 80+80 configuration, after channel coding, data can be processed by a segment parser that can split the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time-domain processing can be performed separately on each stream. These streams can be mapped to two 80MHz channels, and data can be transmitted via the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration can be reversed, and the combined data can be sent to Media Access Control (MAC).

[0065] 802.11af and 802.11ah support operating modes below 1 GHz. Compared to those used in 802.11n and 802.11ac, 802.11af and 802.11ah reduce channel operating bandwidth and carrier. 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 implementations, 802.11ah may support instrument-type control / machine-type communication (MTC), such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including supporting (e.g., only supporting) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain a very long battery life).

[0066] WLAN systems supporting 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. A 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 STAs operating in the BSS (each supporting a minimum bandwidth operating mode). In the 802.11ah example, for STAs supporting (e.g., only supporting) a 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 Sense 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 (supporting only the 1MHz operating mode) is transmitting to the AP, all available frequency bands can be considered busy even if most available bands remain idle.

[0067] 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 available bandwidth for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0068] Figure 1D This is a system diagram illustrating RAN 104 and CN 106 according to an implementation scheme. As noted above, RAN 104 may employ NR radio technology to communicate with WTRUs 102a, 102b, and 102c via air interface 116. RAN 104 may also communicate with CN 106.

[0069] RAN 104 may include gNBs 180a, 180b, and 180c, but it should be understood that RAN 104 may include any number of gNBs while remaining consistent with the implementation. Each gNB 180a, 180b, and 180c may include one or more transceivers for communication with WTRUs 102a, 102b, and 102c via air interface 116. In the implementation, 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 gNBs 180a, 180b, and 180c. Therefore, gNB 180a may, for example, use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a. In the implementation scheme, 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 may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In the implementation scheme, gNBs 180a, 180b, and 180c can implement coordinated multipoint (CoMP) technology. For example, WTRU 102a can receive coordinated transmissions from gNBs 180a and 180b (and / or gNB 180c).

[0070] WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using transmissions associated with an scalable set of parameters. 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 or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing different numbers of OFDM symbols and / or continuously varying absolute time lengths).

[0071] 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 accessing other RANs (e.g., evolved Node Bs 160a, 160b, and 160c). In standalone configuration, WTRUs 102a, 102b, and 102c can use 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 or connect to gNBs 180a, 180b, and 180c, and also communicate or connect to other RANs (such as evolved Node 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 evolved Node Bs 160a, 160b, and 160c. In a non-standalone configuration, evolved Node Bs 160a, 160b, and 160c can be used as mobility anchors for WTRUs 102a, 102b, and 102c, and gNBs 180a, 180b, and 180c can provide additional coverage and / or throughput for serving WTRUs 102a, 102b, and 102c.

[0072] 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 UL and / or DL, network slicing support, interoperability between DC, 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.

[0073] Figure 1DThe CN 106 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 possibly a Data Network (DN) 185a, 185b. Although the foregoing elements are depicted as part of 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.

[0074] AMF 182a and 182b can connect to one or more of the gNBs 180a, 180b, and 180c in RAN 104 via the N2 interface and can be used 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. AMF 182a and 182b can use network slicing to customize CN support for WTRU 102a, 102b, and 102c based on the type of service used by WTRU 102a, 102b, and 102c. For example, different network slices can be established for different use cases, such as services that rely on Ultra-Reliable Low Latency (URLLC) access, services that rely on Enhanced Mobile Broadband (eMBB) access, and services for MTC access. AMF 182a and 182b can provide control plane functions for handover between RAN 104 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.

[0075] SMFs 183a and 183b can connect to AMFs 182a and 182b in CN 106 via the N11 interface. SMFs 183a and 183b can also connect to UPFs 184a and 184b in CN 106 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 DL data notifications. PDU session types can be IP-based, non-IP-based, Ethernet-based, etc.

[0076] UPF 184a and 184b can be connected via the N3 interface to one or more of the gNBs 180a, 180b, and 180c in RAN 104. These gNBs can provide WTRU 102a, 102b, and 102c with access to packet-switched networks (such as the Internet 110) to facilitate communication between WTRU 102a, 102b, and 102c and IP-enabled devices. UPF 184 and 184b can perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multihomed PDU sessions, handling user plane QoS, buffering DL packets, and providing mobility anchoring.

[0077] CN 106 can facilitate communication with other networks. For example, CN 106 may include an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between CN 106 and PSTN 108, or be able to communicate with such an IP gateway. 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. In one embodiment, WTRUs 102a, 102b, and 102c can be connected to DNs 185a and 185b via UPFs 184a and 184b through an N3 interface to UPFs 184a and 184b and an N6 interface between UPFs 184a and 184b and local DNs 185a and 185b.

[0078] Given Figures 1A to 1D as well as Figures 1A to 1D The corresponding descriptions herein refer to one or more of the functions described below, which may be performed by one or more emulation 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. An emulation device may be one or more devices configured to mimic 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.

[0079] Simulation devices can be designed to perform one or more tests on other devices in laboratory and / or carrier network environments. For example, the one or more simulation devices may perform one or more or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. The one or more simulation devices may perform one or more or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. Simulation devices may be directly coupled to another device for testing purposes and / or use over-the-air wireless communication to perform tests.

[0080] The one or more simulation devices may 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 may be used in test scenarios within a test laboratory and / or non-deployed (e.g., testing) wired and / or wireless communication networks to perform testing of one or more components. The one or more simulation devices may be test equipment. Direct RF coupling and / or wireless communication via an RF circuit system (e.g., which may include one or more antennas) may be used by the simulation devices to transmit and / or receive data.

[0081] In some cases, NR sidelinks can support multiple use cases where the WTRU can be remote and mobile (e.g., V2X-related road safety services). In these cases, broadcast, multicast, and unicast communications may exist in both out-of-coverage and NW-coverage scenarios. Additionally, sidelink-based relay functionality can be considered in these cases to extend sidelink / network coverage and improve power efficiency for various application and service scenarios. For WTRU-to-NW coverage extension, the WTRU may require Uu coverage reachability to reach servers in the PDN network or a corresponding WTRU outside the area. However, in some legacy systems, WTRU-to-NW relay is limited to EUTRA-based technologies and therefore cannot be applied to NR-based systems (e.g., for NG-RAN and NR-based sidelink communication). For WTRU-to-WTRU coverage extension, proximity reachability may be limited to single-hop sidelinks via EUTRA-based or NR-based sidelink technologies. However, given the limited single-hop sidelink coverage, this may not be sufficient in scenarios without Uu coverage. In summary, sidelink connectivity needs to be further extended within the NR framework to support, for example, enhanced QoS requirements.

[0082] For single-hop NR sidelink trunks, it may be desirable to have a method to address the requirements of sidelink-based WTRU to NW and WTRU to WTRU trunks. In one example, since Layer 3 trunks and Layer 2 trunks (e.g., RAN2) are involved, the following aspects may be of concern: trunk (re)selection criteria and procedures; trunk / remote WTRU authorization; QoS for trunk functionality; service continuity; security of trunk connections after SA3 has provided its conclusions; and / or the impact on user plane protocol stack and control plane procedures (e.g., connection management of trunk connections).

[0083] Furthermore, for single-hop NR sidelink relay, assuming no physical layer channel / signal (e.g., RAN2), it may be desirable to have a method for upper-layer operation of the discovery model / procedure for sidelink relay.

[0084] In some instances, WTRU to NW trunks and WTRU to WTRU trunks can use the same trunking method.

[0085] In some instances, a Layer 2WTRU to NW relay can be built from an end-to-end PDCP and hop-by-hop RLC architecture.

[0086] In an example related to WTRU to NW relay in LTE, relaying via ProSe WTRU to NW relay can extend network coverage to an out-of-coverage WTRU by using PC5 (e.g., D2D) between the WTRU outside the coverage area and the WTRU to NW relay. ProSe WTRU to NW relay can provide general L3 forwarding capabilities, which can relay any type of IP traffic between the remote WTRU and the network. One-to-one and one-to-many side-link communication can be used between the remote WTRU and the ProSe WTRU to NW relay. For both the remote WTRU and the relay WTRU, operation on a single carrier (e.g., a public safety ProSe carrier) can be supported (e.g., Uu and PC5 can be the same carrier for both the relay and remote WTRUs). The remote WTRU can be authorized by the upper layer and can operate outside the coverage area on the public safety ProSe carrier or on any supported carrier (including public safety ProSe carriers used for WTRU to NW relay discovery, (re)selection, and communication). ProSe WTRU to NW trunks are always within EUTRAN coverage. ProSe WTRU to NW trunks and remote WTRUs can perform sidelink communication and sidelink discovery.

[0087] Relay selection / reselection for ProSeWTRU to NW relays can be performed based on a combination of AS layer quality measurements (e.g., RSRP) and / or upper-layer standards. In one case, the eNB can control whether a WTRU can act as a ProSeWTRU to NW relay. In one example, if the eNB broadcasts any information associated with ProSe WTRU to NW relay operation, ProSe WTRU to NW relay operation can be supported in the cell. In another example, if the ProSe WTRU to NW relay is initiated by broadcast signaling, ProSe WTRU to NW relay discovery can be performed when it is in RRC_IDLE, and / or if the ProSe WTRU to NW relay is initiated by dedicated signaling, relay discovery can be performed as long as it is in RRC_CONNECTED. In another example, the eNB may provide one or more of the following: transmit resources for ProSe WTRU to NW relay discovery using broadcast signaling for the RRC_IDLE state and dedicated signaling for the RRC_CONNECTED state; receive resources for ProSe WTRU to NW relay discovery using broadcast signaling; if the eNB does not broadcast a pool of transmit resources for ProSe-WTRU to NW relay discovery, the WTRU may initiate a request for ProSe-WTRU to NW relay discovery resources via dedicated signaling, taking into account these broadcast thresholds; and / or the eNB may broadcast ProSe... The minimum and / or maximum Uu Link Quality (RSRP) thresholds that a WTRU to NW relay needs to consider before it can initiate a WTRU to NW relay discovery process are as follows: In RRC_IDLE, the WTRU can use this threshold to autonomously start or stop the WTRU to NW relay discovery process when the eNB broadcasts the transmission resource pool; in RRC_CONNECTED, the WTRU can use this threshold to determine whether it can indicate to the eNB that it is a relay WTRU and wants to start ProSe WTRU to NW relay discovery.

[0088] A ProSe WTRU to NW trunk performing sidelink communication for ProSe WTRU to NW trunk operations may need to be in the RRC_CONNECTED state. After receiving a Layer 2 link establishment request or TMGI monitoring request (e.g., an upper-layer message) from a remote WTRU, the ProSe WTRU to NW trunk can indicate to the eNB that it is a ProSe WTRU to NW trunk and intends to perform ProSe WTRU to NW trunk sidelink communication. The eNB can provide resources for ProSe WTRU to NW trunk communication.

[0089] The remote WTRU can decide when to begin monitoring ProSe WTRU to NW relay discovery. Depending on the configuration of the resources used for ProSe WTRU to NW relay discovery, the remote WTRU can transmit ProSe WTRU to NW relay discovery solicitation messages when it is in RRC_IDLE or RRC_CONNECTED state. The eNB can broadcast a threshold that the remote WTRU uses to determine whether it can transmit ProSe WTRU to NW relay discovery solicitation messages to connect or communicate with the ProSe WTRU to NW relay WTRU. The RRC_CONNECTED remote WTRU can use the broadcast threshold to determine whether it can indicate to the eNB that it is a remote WTRU and wants to participate in ProSe WTRU to NW relay discovery and / or communication. The eNB can use broadcast or dedicated signaling to provide transmit resources and broadcast signaling to provide receive resources for ProSe WTRU to NW relay operation. When RSRP exceeds the broadcast threshold, the remote WTRU can stop using ProSe WTRU to NW relay discovery and communication resources.

[0090] It should be noted that the exact timing of traffic switching from Uu to PC5 or from PC5 to Uu can be traced back to higher layers.

[0091] The remote WTRU can perform radio measurements at the PC5 interface and use these measurements, along with higher-layer standards, for ProSe WTRU to NW trunk selection and reselection. A ProSe WTRU to NW trunk is considered suitable in terms of radio standards if the PC5 link quality exceeds a configured threshold (e.g., pre-configured or provided by the eNB). The remote WTRU can select a ProSe WTRU to NW trunk that meets higher-layer standards and has the best PC5 link quality among all suitable ProSe WTRU to NW trunks.

[0092] A remote WTRU can trigger a ProSe WTRU to NW trunk reselection under the following conditions: the PC5 signal strength of the current ProSe WTRU to NW trunk is lower than the configured signal strength threshold; and / or the remote WTRU receives a Layer 2 link release message (e.g., an upper-layer message from the ProSe WTRU to NW trunk).

[0093] In some scenarios, WTRU-to-NW trunks exist operating in RANs relevant to commercial use cases, such as those tailored for wearable and IoT devices. Unlike ProSe WTRU-to-NW trunks, which can use L3 (e.g., IP layer) trunking methods, wearable device WTRU-to-NW trunks can be based on… Figure 2 and / or Figure 3 The example shows an L2 relay in the protocol stack.

[0094] Figure 2 An example of a user plane radio protocol stack for a WTRU to NW relay (e.g., PC5) for Layer 2 evolution is shown. The protocol stack can be shown across multiple entities, such as the remote WTRU at 201, the L2 relay WTRU at 202, the eNB at 203, and the CN at 204.

[0095] Figure 3 An example of a control plane radio protocol stack for a WTRU to NW relay (e.g., PC5) used for Layer 2 evolution is shown. The protocol stack can be shown across multiple entities, such as the remote WTRU at 201, the L2 relay WTRU at 202, the eNB at 203, and the CN at 204.

[0096] In some instances, relay methods (e.g., in LTE) can be based on a one-to-one communication link established at an upper layer (e.g., the ProSe layer) between two WTRUs (e.g., a remote WTRU and a WTRU-to-NW relay). Such a connection can be transparent to the AS layer and connection management signaling, and the procedures performed at the upper layer can be carried by the AS layer data channel. Therefore, the AS layer may be unaware of the one-to-one connection. In some instances (e.g., NR V2X), the AS layer can support the concept of a unicast link between two WTRUs. This unicast link can be initiated by an upper layer (e.g., as in a ProSe one-to-one connection). However, the AS can be informed of the existence of the unicast link and any data transmitted between peer WTRUs in a unicast manner. Utilizing this knowledge, the AS layer can support HARQ feedback, CQI feedback, and unicast-specific power control schemes. As described herein, one or more procedures can exist for establishing a connection for a unicast link in NR (e.g., V2X NR).

[0097] Unicast links at the AS layer can be supported via PC5-RRC connections. A PC5-RRC connection can be a logical connection between a source layer 2ID and a destination layer 2ID pair in the AS. One PC5-RRC connection can correspond to one PC5 unicast link. PC5-RRC signaling can be initiated after its corresponding PC5 unicast link is established. When the PC5 unicast link is released as indicated by the upper layer, the PC5-RRC connection and the corresponding sidelink SRB and DRB can be released.

[0098] For each unicast PC5-RRC connection, a sidelink SRB can be used to transmit PC5-S messages before PC5-S security is established. A sidelink SRB can be used to transmit PC5-S messages to establish PC5-S security. A sidelink SRB can be used to transmit PC5-S messages after PC5-S security has been established, and to protect those messages. A sidelink SRB can be used to transmit PC5-RRC signaling, to protect that signaling, and to send it only after PC5-S security has been established.

[0099] PC5-RRC signaling may include sidelink configuration messages (RRCReconfigurationSidelink), in which one WTRU configures the RX-related parameters for each SLRB in the peer WTRU. Such reconfiguration messages can configure parameters for each protocol in the L2 stack (SDAP, PDCP, etc.). The receiving WTRU can acknowledge or reject such configurations, depending on whether it can support the configuration suggested by the peer WTRU.

[0100] Figure 4 An example of the user plane stack for an NR L2 WTRU to NW relay (without an adaptation layer at PC5) is shown. The protocol stack can be shown across multiple entities, such as the remote WTRU at 401, the WTRU to NW relay at 402, the gNB at 403, and the 5GC at 404.

[0101] Figure 5 An example of a control plane protocol stack for an L2 WTRU to NW relay (without an adaptation layer at PC5) is shown. The protocol stack can be shown across multiple entities, such as the remote WTRU at 501, the WTRU to NW relay at 502, the gNB at 503, and the 5GC at 504.

[0102] The protocol stack for the user plane and control plane of the NR L2 WTRU to NW relay architecture is in Figure 4 and Figure 5 The example is shown.

[0103] For L2 WTRU to NW trunks, the adaptation layer can be placed on top of the RLC sublayer for both the CP and UP at the Uu interface between the trunk WTRU and gNB. Uu SDAP / PDCP and RRC can terminate between the remote WTRU and gNB, while RLC, MAC, and PHY can terminate on each link (e.g., the link between the remote WTRU and the WTRU to NW trunk WTRU, and the link between the WTRU to NW trunk WTRU and gNB).

[0104] Figure 6An example of a user plane protocol stack for an L2 WTRU to NW trunk (with an adaptation layer supported at the PC5 interface) is shown. The protocol stack can be shown across multiple entities, such as the remote WTRU at 601, the WTRU to NW trunk at 602, the gNB at 603, and the 5GC at 604.

[0105] Figure 7 An example of a control plane protocol stack for an L2 WTRU to NW trunk (with an adaptation layer supported at the PC5 interface) is shown. The protocol stack can be shown across multiple entities, such as the remote WTRU at 701, the WTRU to NW trunk at 702, the gNB at 703, and the 5GC at 704.

[0106] Depending on the situation, the adapter layer may or may not be supported at the PC5 interface between the remote WTRU and the relay WTRU.

[0107] For L2 WTRU to NW relay, for the uplink, the Uu adaptation layer at the relay WTRU can support UL bearer mapping between the ingress PC5 RLC channel used for relay and the egress Uu RLC channel above the relay WTRU Uu path. For uplink relay traffic, different end-to-end RBs (SRB, DRB) of the same remote WTRU and / or different remote WTRUs can undergo N:1 mapping and data multiplexing over a single Uu RLC channel.

[0108] Furthermore, for L2 WTRU to NW trunks, for the uplink, the Uu adapter layer can be used to support remote WTRU identification for UL traffic (e.g., multiplexing data from multiple remote WTRUs). The identification information of the remote WTRU Uu radio bearer and the remote WTRU can be included in the Uu adapter layer at the UL so that the gNB can associate received data packets for the specific PDCP entity associated with the correct remote WTRU Uu radio bearer.

[0109] For L2 WTRU to NW relay, for the downlink, the Uu adaptation layer can be used to support DL bearer mapping at the gNB to map end-to-end radio bearers (e.g., SRBs, DRBs) of the remote WTRU to a UuRLC channel over the relay WTRU Uu path. The Uu adaptation layer can also be used to support DL N:1 bearer mapping and data multiplexing between multiple end-to-end radio bearers (e.g., SRBs, DRBs) of the remote WTRU and / or different remote WTRUs and a single Uu RLC channel over the relay WTRU Uu path.

[0110] For L2 WTRU to NW relay, the Uu adaptation layer may need to support remote WTRU identification for downlink traffic. The identification information of the remote WTRU Uu radio bearer and the identification information of the remote WTRU may need to be placed by the gNB at the DL in the Uu adaptation layer so that the relay WTRU can map data packets received from the remote WTRU Uu radio bearer to its associated PC5 RLC channel.

[0111] In the case of L2 WTRU to NW relay, the gNB implementation can handle QoS failures on Uu and PC5 by performing end-to-end QoS enforcement for a specific session established between the remote WTRU and the network. The handling details when PC5 RLC channels with different end-to-end QoS are mapped to the same Uu RLC channel are described in this paper.

[0112] To ensure AS layer service continuity, in some cases, L2 WTRU to NW relay can use RAN2 technology regarding the NR handover process. For example, when a gNB hands over a remote WTRU to a target cell or target relay WTRU, it includes: 1) a handover preparation process between the gNB and the relay WTRU (if needed), 2) an RRC Reconfiguration to the remote WTRU, the remote WTRU handing over to the target, and 3) a handover completion message.

[0113] This article can describe the exact content of a message (e.g., a toggle command).

[0114] Figure 8An example of a procedure for a remote WTRU to switch to a direct Uu cell (e.g., from an indirect path to a direct path) is shown. For service continuity from an L2 WTRU to an NW relay, a baseline procedure (e.g., remote WTRU to direct Uu cell) with one or more of the following steps can be used. Initially, at 801, a connection exists between the remote WTRU 810 with relay WTRU 811 and the base station (e.g., gNB) 812. At 802, measurement configuration and reporting may be present. At 803, the network / base station 812 may decide to switch to a direct cell (e.g., based on measurements). At 804, the base station 812 may send an RRC reconfiguration message to the remote WTRU 810. At 805, the remote WTRU 810 may perform a random access with the base station 812. At 806, the remote WTRU may use the target configuration provided in the RRC reconfiguration message at 804 to send feedback to the base station 812 via the target path, including RRCReconfigurationComplete. At point 807, an RRC reconfiguration can be sent to trunk WTRU 811. At point 808, the PC5 link can be released between remote WTRU 810 and trunk WTRU 811 if needed. At point 809, the data path can be switched to resume / start data exchange (e.g., it does not involve the trunk, ultimately switching from an indirect path to a direct path). Note that... Figure 8 The order of the exemplary processes described herein should not be interpreted as restrictive and may be reordered (e.g., 807 before or after 804, 808 after 804 or 806, or 809 after 806). Furthermore, one or more steps in the process may be excluded. Additionally, in some cases, the remote WTRU810 may suspect data transmission via the relay link after 804. In some cases, 808 may be replaced by PC5.

[0115] Figure 9An example of a procedure for a remote WTRU to switch to an indirect relay WTRU is shown. For service continuity from an L2 WTRU to an NW relay, a baseline procedure with one or more of the following steps can be used (e.g., in the case of a remote WTRU switching to a direct Uu cell). Initially, at 901, a connection exists between a remote WTRU 910 with relay WTRU 911 and a base station (e.g., gNB) 912. At 902, after the remote WTRU measures / discovers candidate relay WTRUs, the remote WTRU 910 reports one or more candidate relay WTRUs (e.g., 911 and others). In some cases, the remote WTRU 910 may filter appropriate relay WTRUs that meet certain criteria (e.g., provided by a higher layer) at the time of reporting. The report may include the relay WTRU's ID and SL RSRP information, where such details of the measurements on PC5 can be further described herein. At 912, network / base station 912 can decide to switch to target relay WTRU 911, and optionally at 904, target (re)configuration can be sent to relay WTRU 911 (e.g., during preparation, such as an RRC exchange including configuration and completion messages). At 905, an RRC reconfiguration message can be sent from base station 912 to remote WTRU 910. This may include the following information: the identifier of target relay WTRU 911; and / or target Uu and PC5 configuration. At 906, if a connection has not yet been established, remote WTRU 910 can establish a PC5 connection with target relay WTRU 911. At 907, remote WTRU 910 can use the target configuration provided in RRCReconfiguration to send feedback to base station 912 via the target path (e.g., through relay WTRU 911), including RRCReconfigurationComplete. At 908, a data path switch (e.g., from direct to indirect) can be completed. Note that... Figure 9 The order of the processes shown should not be considered restrictive and can be reordered. Furthermore, one or more steps in the process can be excluded. For example, 903 can occur after the relay WTRU 911 is connected to the base station 912 (e.g., after step 906), if it has not occurred before; and / or 906 can occur before 903, 904, or 905.

[0116] Regarding connection management, in some cases, remote WTRUs need to establish their own PDU session / DRB with the network before user plane data transmission.

[0117] The PC5-RRC aspect of the NR V2X PC5 unicast link establishment process can be reused to establish a secure unicast link between a remote WTRU and a relay WTRU for L2 WTRU to NW relay before the remote WTRU establishes a Uu RRC connection to the network via the relay WTRU.

[0118] For both cases within and outside coverage, when the remote WTRU initiates the first RRC message for establishing its connection with the base station, the PC5 L2 configuration for transmission between the remote WTRU and the WTRU to the NW relay WTRU can be based on the RLC / MAC configuration defined in the specification.

[0119] The establishment of Uu SRB1 / SRB2 and DRB for remote WTRUs can follow the traditional Uu configuration process used for L2 WTRU to NW relay.

[0120] Figure 10 An exemplary procedure for establishing a connection with a remote WTRU is illustrated. This example demonstrates an advanced connection establishment procedure and can be applied to one or more L2 WTRUs to NW relays. A remote WTRU 1010, a relay WTRU 1011, and a base station 1012 (e.g., a gNB) may be present. At 1001, the remote WTRU 1010 and relay WTRU 1011 may perform a discovery procedure and establish a PC5-RRC connection using a legacy procedure as a baseline. At 1002, the remote WTRU 1010 may use the default L2 configuration on the PC5 to send a first RRC message (e.g., an RRCSetupRequest) via relay WTRU 1011 for establishing its connection with the base station. The base station 1012 may respond to the remote WTRU 1010 with an RRCSetup message. The RRCSetup delivery to the remote WTRU 1010 may use the default configuration on the PC5. If the relay WTRU 1011 has not yet started in RRC_CONNECTED, it may need to perform its own connection establishment as part of that process. During this process, the relay WTRU 1011 may have additional details regarding forwarding RRCSetupRequest / RRCSetup messages to the remote WTRU 1010, which are not shown in this example, as described herein.

[0121] At point 1003, base station 1012 and relay WTRU 1011 can perform a relay channel establishment procedure over Uu. Based on the configuration from base station 1012, relay WTRU 1011 and / or remote WTRU 1010 can establish an RLC channel for relaying SRB1 to remote WTRU 1010 over PC5. This procedure prepares the relay channel for SRB1. At point 1004, the SRB1 relay channel over PC5 can be used to send a remote WTRU 1010 SRB1 message (e.g., an RRCSetupComplete message) to base station 1012 via relay WTRU 1011. Remote WTRU 1010 can then establish an RRC connection over Uu.

[0122] At 1005, remote WTRU 1010 and base station 1012 can establish security by following procedures (e.g., conventional methods) and can forward security messages via relay WTRU 1011. At 1006, base station 1012 can establish an additional RLC channel between base station 1012 and relay WTRU 1011 for traffic relay. Depending on the configuration from base station 1012, relay WTRU 1011 and / or remote WTRU 1010 can establish an additional RLC channel between remote WTRU 1010 and relay WTRU 1011 for traffic relay. Base station 1012 can send RRCReconfiguration to remote WTRU 1010 via relay WTRU 1011 to establish relay SRB2 / DRB. In response, remote WTRU 1010 can send RRCReconfigurationComplete to base station 1012 via relay WTRU 1011.

[0123] In addition to the connection establishment process, for L2 WTRU to NW trunks, the RRC reconfiguration and RRC connection release processes can reuse existing RRC procedures where the message content / configuration design exceeds this example, and the RRC connection reconstruction and RRC connection recovery processes can reuse existing RRC procedures as a baseline, and then add the above-mentioned connection establishment process for L2 WTRU to NW trunks to handle trunk-specific parts where the message content / configuration design exceeds this example.

[0124] In RRC_CONNECTED, the WTRU can measure multiple beams (at least one) of a cell, and the measurement results (e.g., power values) can be averaged to derive cell quality. In doing so, the WTRU can be configured to consider a subset of the detected beams. Filtering can be performed at two different layers: beam quality is derived at the physical layer, and then cell quality is derived from multiple beams at the RRC layer. Cell quality from beam measurements can be derived in the same manner for both serving and non-serving cells. If the WTRU is configured to do this by the base station, the measurement report can include the measurement results of X best beams.

[0125] Figure 11 An example of a high-level measurement model is shown, which broadly illustrates the evaluation of K beams through filtering and / or measurements at different stages of reporting. It should be noted that the K beams may correspond to measurements on SSB and / or CSI-RS resources configured by the gNB for L3 mobility and detected by the WTRU at L1. Initially, at 1101, K gNB beams may be present (e.g., as observed by the WTRU). It should be noted that any ellipses shown in any figure represent the possibility of multiple things not shown for the sake of simplicity in illustrating the concepts under discussion. At 1102, measurements within the physical layer of the K beams (e.g., beam-specific samples) may be present as input. At 1103, layer 1 filtering can be performed, which is an internal layer 1 filtering of the input measured at 1102. The precision of the filtering can be implementation-dependent. How measurements are actually performed within the physical layer can be implementation-specific (e.g., input 1102 and layer 1 filtering).

[0126] At 1104, measurements (e.g., beam-specific measurements) may exist that are reported from Layer 1 to Layer 3 after Layer 1 filtering. Depending on one or more factors, these 1104 measurements may undergo beam / combining and / or further filtering.

[0127] For example, at 1105, beam combining and / or selection may be present, where beam-specific measurements 1104 are combined to derive further measurements 1106 (e.g., cell quality). The behavior of beam combining / selection 1105 can be normalized, and the configuration of this module can be provided by RRC signaling. Measurement 1106 (e.g., cell quality) can be derived from the beam-specific measurements reported to Layer 3 after beam combining / selection 1105. In one example, the reporting period at 1106 can be equal to one measurement period at 1104. At 1107, Layer 3 filtering for cell quality can be performed, which is a filter of the 1106 measurements. The behavior of Layer 3 filter 1107 can be normalized, and the configuration of the Layer 3 filter can be provided by RRC signaling. Layer 3 filtering can generate measurement 1108. In one example, the reporting rate of measurement 1108 can be the same as the reporting rate at point 1106. Measurement 1108 can be used as input to one or more evaluations of reporting criteria 1110. In one example, the filter reporting cycle at 1108 can be the same as a measurement cycle at 1106.

[0128] At 1110, the evaluation of the reporting criteria can check whether the actual measurement report 1111 is necessary. The evaluation 1110 can be based on more than one measurement stream (e.g., for comparison between different measurements). This is illustrated by inputs 1108 and 1109. At 1110, at least whenever a new measurement result is reported, such as 1108 and 1109, the WTRU can evaluate the reporting criteria. The reporting criteria can be standardized, and the configuration can be provided by RRC signaling (e.g., WTRU measurements).

[0129] 1111 reports (e.g., measurement report information sent in a message) can be sent over the radio interface.

[0130] In some cases, layer 3 (L3) beam filtering can occur at 1112, which is a filtering performed on the measurement at 1104 (e.g., a beam-specific measurement). The behavior of the beam filter at 1112 can be normalized, and the configuration of the beam filter can be provided by RRC signaling. L3 filtering at 1112 can generate measurement at 1113 (e.g., a beam-specific measurement). In one example, the reporting rate of measurement at 1113 can be the same as the reporting rate at 1104. Measurement at 1113 can be used as input for selecting 1114X measurements to be reported (e.g., where X is less than K). The behavior of beam selection at 1114 can be normalized, and the configuration of this module can be provided by RRC signaling.

[0131] At 1115, a measurement report can be transmitted over the radio interface, which may include beam measurement information for the X measurements selected at 1114.

[0132] Layer 1 filtering can introduce a specific level of measurement averaging. How and when exactly the WTRU performs the required measurements can be implementation-specific, such as the degree to which the output at point B meets performance requirements. Layer 3 filtering for cell quality and its associated parameters may not introduce any delay in sample availability between points 1106 and 1108. Measurements at points 1108 / 1109 can be inputs used in event assessment. L3 beam filtering and its associated parameters may not introduce any delay in sample availability between points 1113 and 1115.

[0133] In some cases, measurement reports may include measurement identifiers of associated measurement configurations that triggered the report. In some cases, the cell and beam measurements to be included in the measurement report can be configured by the network. In some cases, the number of non-serving cells to be reported can be limited by network configuration. In some cases, cells belonging to a network-configured blacklist may not be used for event assessment and reporting, and conversely, when a network-configured whitelist is used, only whitelisted cells can be used for event assessment and reporting. In some cases, the beam measurements to be included in the measurement report can be configured by the network (e.g., beam identifier only, measurement result and beam identifier, or no beam reporting).

[0134] If the center frequency of the SSB of the serving cell is the same as the center frequency of the SSB of the neighboring cell, and / or the subcarrier spacing of the two SSBs can also be the same, then SSB-based intra-frequency measurement can be defined as SSB-based intra-frequency measurement.

[0135] If the center frequency of the serving cell's SSB is different from that of the neighboring cell's SSB, and / or the subcarrier spacing of the two SSBs may be different, then SSB-based frequency inter-frequency measurement can be defined as SSB-based frequency inter-frequency measurement.

[0136] For SSB-based measurements, one measurement object can correspond to one SSB, and WTRU can treat different SSBs as different cells.

[0137] If a CSI-RS-based inter-frequency measurement is not a CSI-RS-based intra-frequency measurement, then a CSI-RS-based inter-frequency measurement can be defined as a CSI-RS-based inter-frequency measurement.

[0138] A CSI-RS-based in-frequency measurement can be defined as a CSI-RS-based in-frequency measurement under the following conditions: the SCS of the CSI-RS resource configured for measurement on the neighboring cell is the same as the SCS of the CSI-RS resource indicated for measurement on the serving cell; for SCS = 60 kHz, the CP type of the CSI-RS resource configured for measurement on the neighboring cell is the same as the CP type of the CSI-RS resource indicated for measurement on the serving cell; and / or the center frequency of the CSI-RS resource configured for measurement on the neighboring cell is the same as the center frequency of the CSI-RS resource indicated for measurement on the serving cell.

[0139] In some cases, extended CP may not be supported for CSI-RS based measurements.

[0140] Whether a measurement is non-gap-assisted or gap-assisted can depend on the capabilities of the WTRU, the WTRU's active BWP, and / or the current operating frequency. For SSB-based intra-frequency measurements, if measurement gap requirement information is reported by the WTRU, a measurement gap configuration can be provided based on that information; otherwise, in cases other than the initial BWP, a measurement gap configuration can always be provided if any WTRU-configured BWP does not contain frequency domain resources of the SSB associated with the initial DL BWP. Alternatively / additionally, for SSB-based inter-frequency measurements, if measurement gap requirement information is reported by the WTRU, a measurement gap configuration can be provided based on that information; otherwise, a measurement gap configuration can always be provided if the WTRU only supports per-WTRU measurement gaps; and / or if the WTRU supports per-FR measurement gaps, and any serving cell is within the same frequency range as the measurement object.

[0141] The measurement report configuration can be event-triggered or periodic. If the measurement report configuration is periodic, the WTRU sends a measurement report at each reporting interval (e.g., its range can be between 120ms and 30min).

[0142] For event-triggered measurements, the WTRU sends a measurement report when the conditions associated with the event are met. The WTRU can maintain the measurement serving cell and neighbor report volume and verify the report volume using thresholds or offsets defined in the reporting configuration. The report volume / trigger of an event can be RSRP, RSRQ, and / or SINR. This document also describes specific types of events.

[0143] In some cases (e.g., NR), there may be intra-RAT events and / or inter-RAT events. In some cases, these events can be used as triggers for one or more actions (e.g., measurement, reporting, switching, etc.).

[0144] An intra-RAT event could be event A1, where the serving cell becomes better than a threshold. This can be used to cancel an ongoing handover process. This might be necessary if the WTRU moves toward the cell edge and triggers a mobility procedure, but then subsequently moves back into good coverage before the mobility procedure is complete.

[0145] An intra-RAT event could be event A2, in which service becomes worse than a threshold. Since it does not involve any neighbor cell measurements, A2 can be used to trigger blind mobility procedures, or the network can configure WTRU for neighbor cell measurements when it receives a measurement report triggered by event A2, in order to conserve WTRU battery (e.g., not performing neighbor cell measurements when the serving cell quality is good enough).

[0146] An intra-RAT event can be event A3, where a neighbor becomes offset better than a special cell (SpCell). This is typically used during handover procedures. Note that SpCell can be the primary serving cell (e.g., PCell) of a primary cell group (MCG) or the primary serving cell (e.g., PSCell) of a secondary cell group (SCG). Therefore, in DC operations, the secondary node (SN) can be configured for an A3 event triggered by a PSCell change.

[0147] An in-RAT event could be event A4, where a neighbor becomes better than a threshold. This can typically be used for handover processes that do not depend on the coverage of the serving cell (e.g., load balancing, where the WTRU is switched to a good neighbor cell even if the serving cell conditions are excellent).

[0148] An intra-RAT event could be event A5, where SpCell becomes worse than threshold 1 and a neighbor becomes better than threshold 2. Similar to A3, this can typically be used for handover, but unlike A3, it can provide a handover trigger mechanism based on absolute measurements of the serving and neighboring cells, whereas A3 uses relative comparisons. Therefore, it can be suitable for time-critical handovers when the serving cell weakens and a move to another cell that may not meet the handover criteria for event A3 is necessary.

[0149] An event within a RAT can be event A6, where a neighbor becomes better offset than the SCell. This can be used for SCell addition / release.

[0150] An inter-RAT event could be event B1, where the inter-RAT neighbor becomes better than a threshold. This is equivalent to A4, but for the case of inter-RAT switching.

[0151] An inter-RAT event could be event B2, where PCell becomes worse than threshold 1 and the inter-RAT neighbor becomes better than threshold 2. This is equivalent to A5, but for the case of inter-RAT switching.

[0152] The WTRU's measurement configuration may include an s-measureConfig, which specifies a threshold for NR SpCell RSRP measurement control regarding when the WTRU needs to perform measurements on non-serving cells. This value can be a threshold corresponding to either SSB-RSRP (e.g., cell RSRP based on SS / PBCH blocks) or CSI-RSRP (e.g., cell RSRP corresponding to CSI-RS). If the measured SpCell SSB or CSI RSRP is above the threshold, the WTRU may not perform measurements on non-serving cells, thereby improving WTRU power consumption (e.g., if the WTRU has very good radio conditions toward the serving cell, the WTRU does not perform unnecessary measurements).

[0153] Regarding measurements on the sidelinks related to power control, for coverage operations, the power spectral density of sidelink transmissions can be adjusted based on the path loss from the base station. For unicast, some sidelink transmission power spectral density can be adjusted based on the path loss between two communication WTRUs.

[0154] For side-link measurements related to CSI reporting, the Channel State Information Reference Signal (CSI-RS) can be supported for unicast CSI measurements and reporting in the side-link. CSI reports can be carried within the side-link MAC CE.

[0155] For sidelink measurements related to physical layer measurements, the following WTRU measurements can be supported: PSBCH reference signal received power (PSBCH RSRP); PSSCH reference signal received power (PSSCH-RSRP); PSCCH reference signal received power (PSCCH-RSRP); Sidelink Received Signal Strength Indicator (SL RSSI); Sidelink Channel Occupancy Rate (SL CR); Sidelink Channel Busy Ratio (SL CBR).

[0156] Regarding the configuration and reporting of sidelink measurements, the WTRU can configure its associated peer WTRU to perform NR sidelink measurements and report them on the corresponding PC5-RRC connection based on the NR sidelink measurement configuration used for unicasting via the RRCReconfigurationSidelink message. The NR sidelink measurement configuration can include the following parameters for the PC5-RRC connection: NR sidelink measurement object; NR sidelink reporting configuration; NR sidelink measurement identifier; and / or NR sidelink quantity configuration.

[0157] For an NR sidelink measurement object, there can be an associated peer WTRU on which NR sidelink measurements can be performed. For NR sidelink measurements, the NR sidelink measurement object can indicate the NR sidelink frequency of the reference signal to be measured.

[0158] For NR sidelink reporting configurations, there can be NR sidelink measurement reporting configurations, where each NR sidelink measurement object can have one or more NR sidelink reporting configurations. Each NR sidelink reporting configuration can include the following: reporting criteria, where the criteria that trigger the WTRU to send an NR sidelink measurement report (e.g., is a periodic or single event description); RS type, which can be an RS that the WTRU can use for NR sidelink measurement results, and / or where only DMRS can be supported for NR sidelink measurements; and / or reporting format, where there can be quantities that the WTRU includes in the measurement report, and / or only RSRP measurements can be supported.

[0159] For NR sidelink measurement identifiers, a list of NR sidelink measurement identifiers can exist, where each NR sidelink measurement identifier links an NR sidelink measurement object to an NR sidelink report configuration. By configuring multiple NR sidelink measurement identifiers, it is possible to link more than one NR sidelink measurement object to the same NR sidelink report configuration, and to link more than one NR sidelink report configuration to the same NR sidelink measurement object. NR sidelink measurement identifiers can also be included in the NR sidelink measurement report that triggers the report, serving as a reference for the network.

[0160] For NR sidelink quantity configuration, the NR sidelink quantity configuration can define the NR sidelink measurement filtering configuration used for all event evaluations and related reports, as well as periodic reports for that NR sidelink measurement. In each configuration, different filter coefficients can be configured for different NR sidelink measurements.

[0161] Both WTRUs connected to the PC5-RRC can maintain the NR sidelink measurement object list, the NR sidelink report configuration list, and / or the NR sidelink measurement identifier list according to the signaling and procedures described herein.

[0162] WTRU can derive NR sidelink measurement results by measuring one or more DMRS associated with each PC5-RRC connection, such as those configured by the associated peer WTRU. For all NR sidelink measurement results, WTRU can apply Layer 3 filtering before using the measurement results for evaluation of reporting criteria and measurement reports. In some cases, only NR sidelink RSRPs can be configured as trigger and reporting quantities.

[0163] The following measurement events can be defined for the NR sidelink: event S1, where the serving cell becomes better than a threshold; and / or event S2, where the serving cell becomes worse than a threshold. Measurements based on S1 and S2 (e.g., reports) can be used by the WTRU receiving the report to adjust the power level when transmitting data.

[0164]

[0165]

[0166] Table 1

[0167] Table 1 shows examples of information elements related to sidelink reporting. Note that the ReportInterval and ReportAmount elements under EventTriggerConfig are also discussed in this article.

[0168]

[0169] Table 2

[0170] Table 2 shows examples highlighting information elements in VarMeasReportListSL. The WTRU variable VarMeasReportListSL can include information about NR sidelink measurements where the triggering conditions have been met.

[0171] Regarding Tables 1 and 2, there may be information elements that provide configuration information about measurements and reporting (e.g., provided to WTRU). For example, sl-ReportAmount could be the number of sidelink measurement reports applicable to the sl-EventTriggered report type; sl-ReportInterval could indicate the interval between periodic reports for the sl-EventTriggered report type (e.g., when sl-ReportAmount exceeds 1). In some cases, these information elements may convey the number of reports for the quantity and the time between reports for the interval.

[0172] NR sidelink transmission can have two resource allocation modes: Mode 1, where sidelink resources are scheduled by the base station; and Mode 2, where the WTRU autonomously selects sidelink resources from a (pre-)configured sidelink resource pool based on a channel sensing mechanism. For WTRUs within coverage area, the WTRU can be configured to operate in either Mode 1 or Mode 2. For WTRUs outside coverage area, only Mode 2 can be used.

[0173] To enhance the QoS of NR sidelink transmissions, congestion control can be important (especially in Mode 2) to prevent transmitting WTRUs from consuming too many resources in sidelink transmissions. Two metrics can be defined for this purpose: Channel Busy Ratio (CBR), where CBR is defined as the portion of a subchannel whose RSSI exceeds a pre-configured value over a specific duration; and Channel Occupancy Rate (CR), which, considering a specific time slot n, can be defined as (X+Y)M, where X is the number of subchannels occupied by transmitting WTRUs within [na, n-1], Y is the number of subchannels licensed within [n, n+b], and M is the total number of subchannels within [na, n+b].

[0174] For congestion control, by CR 限制 The upper limit of CR can be imposed on the launch WTRU, where CR 限制 It is a function of the priority of CBR and sidelink transmissions. The amount of resources occupied by the transmitting WTRU cannot exceed the priority of CR. 限制 .

[0175] CBR reports can also be used by the base station to determine the resource pool allocated to sidelink communication (e.g., if a WTRU participating in sidelink communication reports a high CBR, the resource pool is increased; if the reported CBR is low, the resource pool is decreased, etc.).

[0176] In addition to peer WTRUs participating in sidelink operations configuring each other for measurements (e.g., periodic or S1 / S2 events), for operations within coverage (e.g., a remote WTRU within the base station's coverage area), the base station can utilize CBR measurements to configure the remote WTRU, which can also be periodic or event-triggered. The following two measurement events can be configured for CBR measurement reporting: event C1 (the CBR of NR sidelink communication becomes better than an absolute threshold); and event C2 (the CBR of NR sidelink communication becomes worse than an absolute threshold).

[0177] As discussed in this paper, NR sidelink measurements can be configured by the peer WTRU (e.g., with respect to SL-RSRP, which can be periodic or triggered by S1 / S2 events) or by the base station (e.g., gNB) (e.g., with respect to CBR, which can be periodic or triggered by C1 / C2 events).

[0178] In some cases, problems may arise when the base station is unaware of the serving / candidate sidelink radio conditions. In some instances, from the base station's perspective, the sidelink-only measurements received by the base station may be CBR-related, which can be beneficial for congestion control and accordingly increasing / decreasing the resource pool associated with sidelink communication. However, the base station's handover decisions (e.g., indirect-to-direct handover of a remote WTRU) could benefit from additional information. Enhancements may be needed to enable the base station to know the radio conditions on the sidelink between the remote WTRU and the relay WTRU.

[0179] In some instances where the WTRU is not connected to a sidelink, relay link selection and eventual establishment can be performed if the measured sidelink RSRP is above a certain threshold. This threshold can be configured by the network (e.g., within coverage) or can be pre-configured (e.g., outside coverage). Such measurements may also be unavailable at the base station.

[0180] In situations where the base station is unaware of side link measurements (e.g., serving side link or candidate side link), decisions based solely on the WTRU can be made to perform WTRU mobility involving side links (e.g., direct to indirect, indirect to direct, or indirect to indirect), where these decisions can benefit from additional information (e.g., link measurements at remote WTRUs).

[0181] In some cases, problems may arise when attempting to compare sidelink and Uu radio conditions, as well as sidelink and sidelink radio conditions. For base station-controlled handovers (e.g., direct-to-indirect or indirect-to-direct) by a remote WTRU, a method / technique is needed to configure the WTRU to report measurements based on a comparison of radio conditions on the serving sidelink and candidate Uu links (e.g., for indirect-to-direct HO) or the serving Uu link and candidate sidelinks (e.g., for direct-to-indirect HO). Without such a technique, load balancing that resembles only handover (e.g., direct-to-indirect handover based on A2 events) may be possible, and therefore service continuity during mobility considering appropriate measurements of both sidelinks and Uu links may be impossible.

[0182] Similarly, for base station-controlled handovers of remote WTRUs (e.g., indirect-to-indirect), methods / techniques are needed to configure the WTRU to report measurements based on a comparison of radio conditions on the serving side link and candidate side links (e.g., S1 / S2-based measurements could consider only an absolute threshold comparison of the radio quality of the serving side link). Without such methods / techniques, the only way to perform indirect-to-indirect handovers might be an inefficient mechanism where a connection to the serving relay WTRU is determined to be insufficient based on S2 measurements (or periodic measurements on SL-RSRP), and then a discovery operation is performed to find a better side link relay and switch to that side link relay. As described herein, one or more techniques (e.g., systems, methods, and devices) may exist for addressing measurement reporting related to side link operations. These techniques can address one or more problems that may arise in relay scenarios (e.g., those identified herein).

[0183] As discussed in this article, a relay WTRU can be used as a WTRU-to-WTRU relay (e.g., Figure 12 (as shown) or WTRU to NW relay (e.g., as shown) Figure 13 (As shown). While some of the examples discussed herein may relate to specific relay scenarios, these examples are not intended to be limiting, and the technical intent described with respect to each example is interchangeable where applicable.

[0184] Figure 12 An example of a WTRU-to-WTRU relay is shown, while Figure 13 An example of a WTRU to NW relay is shown. Typically, for any relay communication, there is a source WTRU (1201, 1301), one or more relays (e.g., relay WTRU 1202 / 1302 and / or other possible relays 1203 / 1303), and a destination (such as WTRU 1204 and / or base station 1504). Figure 12 As illustrated in the example, the first link 1211 / 1311 corresponds to the link between the source WTRU 1201 / 1301 (also referred to as the remote WTRU) and the relay WTRU 1202 / 1302. The second link 1212 / 1312 refers to the link between the relay WTRU 1202 / 1302 and any of the following: the destination (e.g., 1204 / 1304), where, in this document, the destination can be a WTRU or a network node, depending on whether the relay is a WTRU-to-WTRU relay or a WTRU-to-NW relay; and / or the next-hop WTRU in a multi-hop WTRU-to-WTRU or WTRU-to-NW link (e.g., 1203 / 1303). As disclosed herein, the source WTRU can also be interchangeable with a relay WTRU served by another relay along the link to the destination.

[0185] In some cases, a relay WTRU can be an integrated access and backhaul (IAB) node, which comprises two parts: a distributed unit (DU) connected to a base station of a remote / source WTRU, and a mobile termination (MT) part for connecting to another relay WTRU (e.g., in a multi-hop scenario) or a donor DU of a base station (e.g., in a single-hop scenario).

[0186] Figure 14 An exemplary relay scenario that can be considered for measurement and reporting is shown. Similar to... Figure 13 The example illustrates a WTRU to network relay; however, the schematic diagram is similarly applicable to WTRU to WTRU relays. In a given relay scenario, a remote WTRU 1421 may exist, which establishes and / or has a service-side link to relay WTRU 1411, which in turn acts as a relay to a destination (e.g., gNB) 1431 via a service backhaul link. One possibility for this relay is to send measurement event configurations from base station 1431 to remote WTRU 1421 and to send measurement reports from remote WTRU 1421 to base station 1431. Remote WTRU 1421 can be required to perform measurements and reports on any and / or all links within a given area. For example, measurements can be performed on a potential direct link to base station 1432, a potential side link with another relay WTRU 1412 that will connect to base station 1433, and / or on existing links that have a service-side link with relay WTRU 1411. Figure 14 A general concept that can be understood is that, from the perspective of a given WTRU (e.g., a remote WTRU 1421), it is necessary to measure and report any / all links that are currently present or may exist in a given wireless environment (e.g., through normal operating procedures, where the WTRU may be mobile at some points and stationary at others).

[0187] In one or more examples provided herein where WTRUs are connected via sidelinks, any measurements taken / configured may refer to sidelink measurements for a relay WTRU; however, these examples are not intended to be limiting and can be equally applied to scenarios involving the measurement of candidate sidelinks or other candidate direct links (e.g., for direct-to-indirect mobility, a WTRU directly connected to a base station measures a sidelink to a candidate relay WTRU, or for indirect-to-indirect mobility, a remote WTRU connected to a relay WTRU measures a sidelink to a candidate relay WTRU). Furthermore, while one or more examples provided herein illustrate scenarios involving WTRU-to-network relays, these examples are not intended to be limiting and can be equally applied to scenarios with WTRU-to-WTRU relays (e.g., where a destination base station or WTRU makes a decision and provides configuration information to a remote WTRU).

[0188] Generally speaking, for measurement / reporting in a relay WTRU scenario (e.g., Figure 14 As may be applied herein, a remote WTRU may be configured (e.g., via relay or directly) by a relay WTRU or a base station to perform measurements (e.g., sidelink or direct link), and the remote WTRU may report measurements periodically or on events such as S1 / S2, depending on the configuration (e.g., sidelink relay or direct link with the base station); wherein reporting may be based on one or more conditions as defined herein. Reporting sidelink measurements to the base station may be performed periodically and / or on an event-based basis. Once the base station has a measurement report, it may evaluate the information alone or in combination with other measurements and make decisions regarding coverage management (e.g., handover) in relation to the remote WTRU.

[0189] An IE (Interceptor) can be included in a report configuration (e.g., an SL-ReportConfigInfo IE) that specifies where reports will be sent for all measurements. An IE can also be included in an SL-ReportConfig IE that specifies where reports will be sent for measurements associated with that specific report configuration. If both IEs exist, the IE within SL-ReportConfig takes precedence. The remote WTRU can transmit report configurations (e.g., thresholds, frequency information, etc., in the case of event-triggered reports) to the base station so that the base station can understand SL measurements when it receives a report from the remote WTRU. Some or part of the sidelink measurement configuration (e.g., thresholds, reporting intervals, etc.) can be determined by the base station and sent to the relay WTRU, which then configures the remote WTRU accordingly.

[0190] A relay WTRU can configure a remote WTRU to perform measurements based on one or more conditions. Alternatively, or otherwise, a remote WTRU can decide whether to report measurements to a base station or a relay WTRU, or both, based on one or more conditions. These conditions can be any conditions discussed herein.

[0191] When reporting measurements to the relay WTRU, the remote WTRU can use the SL RRC message. When reporting measurements to the network, the remote WTRU can use the Uu RRC message. The remote WTRU can use two separate RRC messages on different interfaces to report to both the network and the relay WTRU. Alternatively, the remote WTRU can use a single RRC message, the applicable portion of which can be interpreted by both the base station and the relay WTRU.

[0192] Figure 15 A general example of measurement / reporting for a relay scenario is shown. At 1501, the WTRU can receive configuration information, which may include thresholds / conditions for performing and / or reporting measurements. These measurements and / or thresholds may include one or more of the following: CBR, SL RSRP, SL RSRQ, SL RSNI, Direct Link RSRP, Direct Link RSRQ, Direct Link RSNI, priority of active SL RLC channels, UL pending data capacity, etc. At 1502, the WTRU can perform measurements on one or more active and / or potential links. At 1503, the WTRU can evaluate the measurements to determine whether one or more thresholds are met (e.g., above, below, exact match, within range, etc.). If one or more thresholds are met, and / or one or more events (e.g., any of the events described herein) occur, this can trigger actions such as reporting (e.g., depending on the periodic configuration), at which point a measurement may be sent at 1504; otherwise, if the threshold is not met, the measurement and / or analysis of the threshold can continue until the threshold is met, a new configuration is received, or some other related function can be performed by the WTRU. The frequency of measurement / analysis can be configured, as discussed further herein. Alternatively, or in addition to reporting, in some cases, the threshold can trigger handover-related actions. In some cases, in response to sending a report, the WTRU may receive handover-related commands.

[0193] In one instance applicable to any of the examples described herein, after the base station receives the report, it may then send instructions to the remote WTRU, such as handover-related instructions (e.g., cancel handover, continue handover, start handover, etc.). The handover may apply to one or more links of the WTRU, or all links of the WTRU (e.g., dual connectivity, where an auxiliary link is added / removed / changed). In one instance applicable to any of the examples described herein, instead of sending a report, the WTRU may be triggered to perform a handover (e.g., conditional handover) that the base station previously instructed in its configuration information or in a handover command with a triggering mechanism (directly or via a relay) when a threshold is met.

[0194] In one example, a remote WTRU can be configured by a base station to perform sidelink measurements, and the remote WTRU reports the measurements to a relay WTRU, the base station, or both, depending on the configuration (e.g., periodically or on events like S1 / S2). Reporting sidelink measurements to the base station can be performed in a periodic and / or event-based manner.

[0195] The sidelink measurement configuration provided by the base station can be based on existing message / information structures (e.g., SL-ReportConfigInfo, SL-ReportConfig, etc., and associated S1 / S2 events) used for conventional sidelink measurement / reporting configurations for peer WTRUs, or the sidelink measurement configuration can be based on existing message / information structures (e.g., MeasObjectNR, ReportConfigNR, etc., and associated A1 / A2 events) used for conventional Uu measurements. In the latter case, the conventional Uu measurement / reporting configuration can be enhanced to also include sidelink measurement / reporting configuration.

[0196] Generally, the WTRU can have different configurations for measurements to be reported to the base station compared to the measurements to be reported to the relay WTRU, even if they are provided in a single message for measurement and reporting configuration (e.g., an RRC configuration information message with several information elements). For example, there may be: different reporting intervals (e.g., reporting to the relay more frequently than to the base station, or vice versa); different trigger thresholds (e.g., a lower S1 threshold for reporting to the relay than to the base station, or vice versa, a higher S2 threshold for reporting to the relay than to the base station, or vice versa, etc.); and / or different hysteresis or timers for trigger values ​​(e.g., a longer time for triggering a report to the base station compared to a report to the relay, because decisions made by the base station based on the report (e.g., handover-related decisions) can be considered more critical than decisions made in reports to the relay WTRU, since they are used for power control).

[0197] Combinations of more than one method are also possible. For example, a WTRU can be configured independently to perform / report sidelink measurements by a base station (e.g., the second method) and a relay WTRU (e.g., the first method), and to perform measurements and report measurements to the base station and the relay WTRU according to each configuration.

[0198] Figure 16 Examples of CBR / CR related measurements being used to determine when / whether a remote WTRU performs SL-RSRP / RSRQ / RSNI measurements are shown. Generally, CBR / CR related measurements can be used to determine when / whether a remote WTRU performs SL-RSRP / RSRQ / RSNI measurements. This can help avoid unnecessary neighbor measurements and thus save WTRU battery power when there is no congestion in the sidelink. A WTRU can be configured to perform neighbor sidelink measurements only when the CBR / CR on the sidelink is above a specific threshold. A WTRU can be configured to perform neighbor Uu measurements only when the CBR / CR on the sidelink is above a specific threshold, where this threshold can be the same as or different from the CBR / CR threshold to enable neighbor sidelink measurements. A WTRU can be configured to perform either neighbor sidelink or neighbor Uu measurements only when the CBR / CR on the sidelink is above a specific threshold and the SL-RSRP / RSRQ / RSNI measurements are below a specific threshold. A WTRU can be configured to perform serving SL-RSRQ / RSNI measurements only when the CBR / CR is above a specific threshold. For example, if the CBR / CR threshold is below the threshold, the WTRU can only perform SL-RSRP measurements that will be used by the relay WTRU for power control, while when the CBR / CR is above the threshold, the WTRU can begin performing SL-RSRQ measurements that will be used by the base station for mobility determination.

[0199] like Figure 16As shown in the example, at 1601, the WTRU can receive configuration information related to measurement / reporting. This configuration information may include one or more of the following: CBR / CR thresholds for performing neighbor sidelink measurements, such as CBR_SL; CBR / CR thresholds for performing neighbor Uu measurements, such as CBR_Uu; CBR / CR thresholds for performing RSRQ / RSNI sidelink measurements, such as CBR_RSRQ; and / or other related measurements, such as those disclosed herein. At 1602, the WTRU can perform CBR / CR measurements for one or more sidelinks. Next, at 1603 (1603a, 1603b, 1603c), based on the measurement results relative to the previously received thresholds, the WTRU can perform additional measurements of neighbor sidelink RSRP / RSRQ / RSNI at 1604 (1604a, 1604b, 1604c). In some cases, WTRU can selectively perform 1602, 1603, and / or 1603 measurements / evaluations depending on the configuration, even if all measurements / evaluations are performed within the specified range. Figure 16 The example is shown.

[0200] Figure 17 This illustrates an example of how CBR / CR-related measurements can be used to determine when a remote WTRU sends SL-RSRP / RSRQ / RSNI measurements and / or Uu measurements. Generally, CBR / CR-related measurements can be used to determine when a remote WTRU sends SL-RSRP / RSRQ / RSNI measurements and / or Uu measurements. For example, the WTRU can be configured to send SL radio-related measurements and / or Uu measurements when the CBR / CR is above or below a specific threshold. This can also be combined with threshold or periodic reporting configurations similar to S1 / S2. For example, the remote WTRU may send a report only when the CBR / CR threshold is above / below a specific threshold and the SL-RSRP and / or Uu RSRP is above / below another threshold. For example, if the CBR / CR threshold is above / below a specific threshold and the SL-RSRP is above a specific threshold, the WTRU may not send periodic measurement reports.

[0201] like Figure 17As shown in the example, at 1701, the WTRU can receive configuration information related to measurement / reporting. This configuration information may include one or more of the following: CBR / CR thresholds, such as CBR, for sending SL RSRP / RSRQ / RSNI measurements to the base station; other reporting conditions for SL measurements, such as periodicity, SL RSRP / RSRQ / RSNI thresholds; and / or other related measurements, such as those disclosed herein. At 1702, the WTRU can perform one or more sidelink CBR / CR measurements. At 1703, the WTRU can perform sidelink measurements (e.g., RSRP / RSRQ / RSNI). At 1704 and 1705, the WTRU can evaluate whether one or more thresholds indicated in the configuration information are met. It should be noted that 1702, 1703, 1704, and / or 1705 can be performed selectively, meaning that an evaluation of only one threshold is possible, even if... Figure 17 The example illustrates two thresholds. At 1706, the WTRU can report one or more of the configured measurements based on the assessment of the thresholds, such as reporting sidelink RSRP / RSNI / RSRQ measurements and optionally including CBR / CR.

[0202] In one instance, SL-RSRP / RSRQ / RSNI measurements can be used to determine when a remote WTRU sends CBR / CR-related measurements. For example, the WTRU can be configured to send CBR / CR-related measurements when SL-RSRP / RSRPQ / RSNI is above a specific threshold.

[0203] In one instance, SL-RSRP / RSRQ / RSNI measurements can be scaled based on the CBR (e.g., multiplied by a specific scaling factor). For example, when the CBR is below a threshold of 1, the measurement is not scaled; if the CBR is between threshold 1 and threshold 2, the measurement is scaled down by a first scaling factor; when the CBR is above threshold 2, the measurement is scaled down by a second scaling factor, and so on. The amount by which the measurement is scaled can also depend on the SL-RSRP / RSRQ / RSNI being measured. For example, different sets of CBR thresholds corresponding to specific amounts can be configured for each range of SL-RSRP / RSRQ / RSNI.

[0204] Different thresholds and / or quantities can also be configured for reporting Uu measurements and reporting SL measurements.

[0205] In one approach, the WTRU can be configured to perform sidelink measurements and send measurements to the relay WTRU, which then forwards the measurements to the base station. The base station can configure the relay WTRU to forward sidelink measurements and how to forward them. In some cases, all sidelink measurements can be forwarded immediately by the relay WTRU. In other cases, sidelink measurements can only be forwarded if specific conditions / thresholds are met. These conditions can be associated with any of the following: the measurement value itself (e.g., the relay WTRU can forward the measurement only if the value is above a threshold); the measurement of the CBR (e.g., the relay WTRU can determine whether to forward the measurement based on conditions depending on the CBR measured on the SL, such as when the CBR measured on the SL is above / below a threshold); or the Uu measurement (e.g., when Uu...). When RSRP measurements exceed a threshold, the relay WTRU can forward measurements; the RRC status of the relay and / or remote WTRUs (e.g., the relay WTRU can only forward measurements if it is in an RRC connection; e.g., the relay WTRU can only forward measurements if the remote WTRU is in an RRC connection); and / or conditions related to the SL bearer or RLC channel established between the relay and remote WTRUs (e.g., the relay WTRU can only forward measurements if at least one RLC channel that may be associated with the relay of Uu traffic is established between the relay and remote WTRUs; e.g., the relay WTRU can only forward measurements to the network if at least one RLC channel is established, where the configuration of such RLC channels needs to be explicitly or implicitly configured in the configuration (such as being associated with the QoS profile to which the RLC channel is configured).

[0206] A relay WTRU can be configured to forward only a subset of measurement reports it has received from a remote WTRU (e.g., every other measurement, every third measurement, etc.). A relay WTRU can also be configured to perform a certain averaging / filtering of measurements. For example, a relay WTRU can be configured to forward measurements every x measurement reports it receives from a remote WTRU, and include the average of the last n measurements in that report (where x can be the same as or different from n, e.g., x = 10, n = 5).

[0207] A relay WTRU can be configured to periodically forward measurements. For example, a relay WTRU can forward measurement reports every x ms, including the latest measurement results it has received from a remote WTRU.

[0208] If no new measurement report has been received from the remote WTRU since the last time the relay WTRU forwarded the measurement to the base station when it was time to send the next report, the relay WTRU may repeat the last measurement report (e.g., always forward the last measurement report, no matter how recent) or simply provide an indication that no new measurement is available (e.g., send an empty measurement report, send an explicit indication via MAC CE, or other means of indicating that no new measurement is available, such as those disclosed herein).

[0209] A relay WTRU can be configured with a timing profile (e.g., a refresh period) and only reports measurements that are not older than that timing profile. In one scenario, if a report is not recent enough, the relay WTRU can suppress the transmission of any report (e.g., by sending an indication of the report via an empty measurement report or by sending an explicit indication via MAC CE or other means). In another scenario, the relay WTRU can forward reports that do not meet a refresh criterion but include an indication of that refresh criterion. This indication can be a simple flag indicating that the report is not recent, or it can be explicit timing information indicating the time elapsed since the measurement report was received at the relay WTRU or only an additional time after the refresh period. For example, if a measurement report was received 150 ms ago and the refresh period is 100 ms, the relay WTRU can indicate 150 ms (in the former case) or 50 ms (in the latter case).

[0210] The relay WTRU can be provided with an averaging / filtering window, which can be based on the duration or number of measurements. This averaging / filtering window can be used to average / sum the measurements received from the remote WTRU before forwarding them to the base station. In some cases, the averaging window duration can be the same as the reporting period (e.g., the relay WTRU averages all measurement reports received by the remote WTRU every x ms and also forwards measurements every x ms). In other cases, the averaging window can be different from the reporting period (e.g., reports are sent every x ms, but the averaging only considers measurements received in the last y ms). A similar consideration can be made when averaging is based on the number of measurements (e.g., reports are sent every x ms, but only the last n measurements received during that period are considered).

[0211] A relay WTRU can be configured with thresholds and other filtering parameters and can forward measurements from a remote WTRU when one or more criteria are met. One criterion could be that the relay WTRU can be configured with a threshold (e.g., threshold 1), and if the measurement is below that threshold, the measurement received from the remote WTRU is forwarded. Another criterion could be that the relay WTRU can be configured with a threshold (e.g., threshold 2), and if the measurement is above that threshold, the measurement received from the remote WTRU is forwarded. A third criterion could be that the relay WTRU can be configured with two thresholds (e.g., threshold 1 and threshold 2), and if the measurement falls between these two thresholds, the measurement received from the remote WTRU is forwarded. Trigger time to trigger (TTT) and / or hysteresis / offset values ​​can also be included in the criteria, and these can be used by the relay WTRU to ensure that measurements are not forwarded based on only one measurement report. For example, when a measurement received from a remote WTRU meets a criterion (e.g., below a certain threshold, above a certain threshold, etc.), the relay WTRU can start a timer (e.g., with a value set to TTT) and forward the measurement to the base station only if no measurement that does not meet the criterion is received from the remote WTRU.

[0212] In the methods / examples described herein, the average can be a simple linear average (e.g., all measurements are considered to have equal weights), or the average can be time-biased, where more recent measurements have greater weights than older measurements.

[0213] In one scenario, the relay WTRU can send measurements it has already performed on the sidelink to the base station. These measurements can be sent individually or in combination with measurements performed by a remote WTRU, which are forwarded according to any of the methods / examples described herein. If sent individually, the relay WTRU can be configured with settings that apply only to measurements performed by the relay WTRU, such as periodicity, average window, trigger time, hysteresis, etc. If sent together, the same or different configurations can be provided for the measurements performed by the relay WTRU and the remote WTRU.

[0214] In one scenario, the relay WTRU can provide sidelink measurements on demand based on an explicit request from the base station (e.g., measurements performed by a remote WTRU or by the relay WTRU itself). In this explicit request (e.g., an RRC message, MAC CE, etc.), the base station can indicate additional parameters such as whether the desired measurement was performed by the relay WTRU and / or a remote WTRU, a threshold, an averaging window, etc. (e.g., the base station can instruct the relay WTRU to send a linearly averaged measurement result from the remote WTRU during the last x ms period, or to send a report only if the result is above a certain threshold, etc.).

[0215] In one approach, the WTRU can be configured to measure / report additional measurements. In some cases of conventional sidelink measurements, only SL-RSRP may be considered. While this may be sufficient for some situations, such as power control by a peer WTRU, it may be beneficial to consider signal quality in addition to signal strength for handover. For example, the WTRU (remote or relay WTRU) can be configured to perform and report measurements based on SL-RSRQ or SL-SINR (e.g., thresholds associated with enhanced S1 / S2-like measurements discussed above, to consider RSRQ instead of RSRP or in addition to RSRP). The remote WTRU can be configured to measure and report one quantity for the relay WTRU and another quantity for the base station, according to any of the techniques described herein. For example, the WTRU can be configured with an S1-like measurement including both SL-RSRP and SL-RSRQ thresholds, and the WTRU reports the measurement to the relay WTRU when the SL-RSRP threshold is met, and to the base station only when the SL-RSRQ threshold is met. Note that the trigger quantity does not necessarily have to be the same as the reported quantity. Continuing with the previous example, when reporting to the base station based on the SL-RSRQ threshold being met, the WTRU can include the RSRP and / or RSRQ results in the measurement report.

[0216] In one approach, the sidelink measurement configuration can have different thresholds (or other parameters such as TTT, hysteresis, average window, reporting interval, etc.) depending on how the sidelink measurement is performed and / or which SL channel or SL message is being used to perform the measurement. For example, the WTRU can be configured with different sets of parameters, using a first set when sidelink measurements are performed based solely on discovery signals (e.g., when no data is transmitted via the sidelink), and another set of parameters when sidelink measurements are performed based on data (e.g., when data is transmitted via the sidelink).

[0217] Additionally, another set of parameters can be used when performing sidelink measurements based on both data and discovery signals. Furthermore, different parameter sets can be configured if the WTRU uses RS transmitted along with the data from the peer WTRU to perform measurements on the data, or if the WTRU uses SL-RSRP reports sent by the peer WTRU to perform measurements on the data. The sidelink measurements concerning data as defined herein can refer to generating measurement reports (e.g., to be sent to the base station) from measurements of SL RS transmitted along with the data (by the peer WTRU), or generating such measurements from measurements of SL-RSRPs sent by the peer WTRU.

[0218] The WTRU can change from one set of parameters to another based on one or more of the following: when the WTRU starts measuring different channels (e.g., when measurements of data become available or data begins to be transmitted); a period of time after the WTRU starts measuring different channels (e.g., some (pre-)configured time after data becomes available), where such time may also depend on which channel (discovery or data) is the new target channel being measured; and / or when a specific amount / percentage (e.g., most / all) of the measurements averaged by L3 filtering is associated with different channels.

[0219] In one approach, the WTRU can be configured with rules / conditions regarding when it performs measurements of the discovery signal and / or measurements of the data. Sidelink measurements of data, as defined herein, can refer to generating a measurement report (e.g., to be sent to the base station) from measurements of SL RS transmitted along with the data (by the peer WTRU), or generating such measurements from measurements of SL-RSRP transmitted by the peer WTRU. Specifically, the sidelink measurement report sent to the base station can be any or a combination of measurements of discovery, measurements of RS transmitted from the peer WTRU, or measurements based on SL-RSRP reports received from the peer WTRU.

[0220] The WTRU may potentially transmit all available measurements to the base station in the same / different measurement reports and / or by identifying a specific measurement type. Alternatively, the WTRU may transmit a specific type of measurement based on specific rules / conditions that may be associated with that measurement. If such conditions are met, these conditions may cause the WTRU to measure / transmit one type of measurement (opposite to another type of measurement, or otherwise). Such rules / conditions can be any one or a combination of the following: The existence of a discovery transmission from a peer WTRU (e.g., if the discovery transmission is configured by the WTRU / peer WTRU, or if the WTRU receives a discovery, the WTRU can perform / send a measurement based on the discovery); the existence / absence of an SL-RSRP report from the peer WTRU or an SL-RSRP configured by the peer WTRU at the WTRU (e.g., the WTRU can perform / send a measurement if data is unavailable); the existence / absence of data for receiving / transmitting (e.g., when data for transmitting is unavailable and therefore there is no opportunity to request SL measurements about the data, the WTRU can perform SL measurements only on the discovery); based on the nature / frequency of the data transmission (e.g., whether the transmission and / or reception are periodic, and / or whether the period meets a specific criterion). The WTRU may perform SL measurements based on several criteria, such as: (e.g., if the WTRU does not have periodic data reception that it can use to perform measurements, the WTRU may perform SL measurements only on discovery); (e.g., based on the WTRU's transmit power, the WTRU may perform / transmit SL measurements on data, such as based on received SL-RSRP reports, when the WTRU's transmit power is above / below a threshold); (e.g., SL congestion measurements, such as CBR / CR, where the WTRU may transmit only one type of measurement, such as discovery only, when multiple measurements are available, and otherwise, it may transmit all types of measurements); and / or based on measurement values, such as the WTRU may transmit measurement reports of measurement types with maximum / minimum values; for example, if the measurement value is above / below a threshold, the WTRU may transmit a specific measurement report of a given type.)

[0221] In one instance, the WTRU can average values ​​associated with different measurement types before sending measurement reports to the network. The WTRU can also indicate which measurement type(s) are included in the average measurement.

[0222] In some cases, particularly in relay scenarios, it can be useful to compare measurements of more than one link at a remote WTRU (such as comparing side links and Uu / side links). In some cases, reports used for these comparisons may have specific triggering events, where a specific result of the comparison occurs.

[0223] In one approach, the WTRU can be configured to perform / report measurements based on comparing sidelink and Uu measurements to absolute thresholds, or to each other.

[0224] In one example of an absolute comparison, the WTRU can be connected to its destination via a direct link, and the adjacent link (e.g., a candidate link) can be a side link (e.g., the event could be that the SpCell becomes worse than a first threshold, and the neighboring side link becomes better than a second threshold). In another example of an absolute comparison, the WTRU can be connected to a side link, and the adjacent link can be a Uu link (e.g., the event could be that the serving side link becomes worse than a first threshold, and the neighboring Uu becomes better than a second threshold).

[0225] In one example of a relative comparison, the WTRU can currently be connected to a direct link, and the adjacent link is a side link (e.g., the event could be a case where the neighboring side link becomes a better offset than the PCell / PSCell; alternatively / in addition, this could be an event where the inter-RAT side link neighbor becomes a better offset than the PCell / PSCell). In another example of a relative comparison, the WTRU can be connected to a side link, and the adjacent link is a side link (e.g., the event could be a case where the neighbor becomes a better offset than the serving side link; alternatively / in addition, this could be an event where the inter-RAT neighbor becomes a better offset than the serving side link).

[0226] In one approach, the WTRU can be configured with different parameters for sidelink and Uu measurements, such as when the WTRU is receiving configuration information related to measurement events disclosed herein. For example, in some types of measurements (e.g., NR), the parameters reportInterval and reportAmount (e.g., information elements) can be specified when configured for event-triggered measurements, and the WTRU can send the reportAmount of the measurement report at each reportInterval once a measurement report has been triggered (e.g., the conditions configured for the event are met). Different reportInterval and reportAmount values ​​can be configured for sidelink and Uu measurements, and once an event is triggered, the WTRU can send sidelink measurements according to the corresponding sidelink parameters and Uu measurements according to the corresponding Uu parameters.

[0227] In one approach, measurement configurations based on absolute or relative events can be provided to the WTRU by the relay WTRU, the base station, or a combination of both. For example, in the case of an absolute comparison where the WTRU is currently indirectly connected, the relay WTRU can provide thresholds for sidelink-related measurements, while the base station provides thresholds for Uu-related measurements.

[0228] In one approach, absolute and relative conditions can be considered for CBR / CR related measurements as an alternative to or supplement to SL-RSRP / RSRQ / RSNI measurements.

[0229] In an example of an absolute comparison, the WTRU can be connected to a direct link, and the adjacent (e.g., candidate) link is a side link (e.g., the event could be that the SpCell radio becomes worse than a first threshold and the neighboring side link CBR / CR becomes less than a second threshold; for example, this could be that the SpCell radio becomes worse than a first threshold and the neighboring side link CBR / CR becomes less than a second threshold, or the neighboring side link radio quality becomes better than a third threshold; and / or the event could be that the SpCell radio becomes worse than a first threshold and the neighboring side link CBR / CR becomes less than a second threshold, and the neighboring side link radio quality becomes better than a third threshold).

[0230] In an example of absolute comparison, the WTRU can be connected via a side link, and the neighbor link is a side link (e.g., the event could be that the serving side link CBR / CR becomes greater than a first threshold and the neighbor Uu radio becomes better than a second threshold; for example, the event could be that the serving side link CBR / CR becomes greater than a first threshold, or the serving side link radio quality becomes worse than a third threshold and the neighbor Uu radio becomes better than a second threshold; and / or for example, the event could be that the serving side link CBR / CR becomes greater than a first threshold, and the serving side link radio quality becomes worse than a third threshold and the neighbor Uu radio becomes better than a second threshold).

[0231] In one example of a relative comparison, the WTRU can currently be connected via a direct link, and the adjacent link is a side link (e.g., this could be an event where the neighboring side link radio quality becomes an offset better than PCell / PSCell, or the neighboring side link CBR / CR becomes below a first threshold; e.g., this could be an event where the neighboring side link radio quality becomes an offset better than PCell / PSCell, and the neighboring side link CBR / CR becomes below a first threshold; e.g., this could be an event where the inter-RAT side link neighboring radio quality becomes an offset better than PCell / PSCell, or the inter-RAT side link neighboring CBR / CR becomes below a first threshold; and / or e.g., this could be an event where the inter-RAT side link neighboring radio quality becomes an offset better than PCell / PSCell, and the inter-RAT side link neighboring CBR / CR becomes below a first threshold).

[0232] In one example of a relative comparison, the WTRU can be connected via a side link, and the adjacent link is a side link (e.g., this could be an event where the neighbor becomes a better offset than the serving side link, or the serving side link CBR / CR becomes greater than a first threshold; e.g., this could be an event where the adjacent link becomes a better offset than the serving side link, and the serving side link CBR / CR becomes greater than a first threshold; e.g., this could be an event where the inter-RAT neighbor side link becomes a better offset than the serving side link, or the serving side link CBR / CR becomes greater than a first threshold; and / or e.g., this could be an event where the inter-RAT adjacent link becomes a better offset than the serving side link, and the serving side link CBR / CR becomes greater than a first threshold).

[0233] Based on one or more of the techniques described herein, in a relay scenario, a WTRU can be configured to operate as a remote WTRU for connecting to a base station (e.g., gNB) via a relay WTRU. In one example, the remote WTRU can perform one or more of the following operations: the WTRU receives a measurement configuration related to a side link from an NW or relay WTRU; the measurement configuration includes a channel busy rate / channel occupancy rate (CBR / CR) threshold for performing measurements on adjacent (e.g., non-serving) radio links (e.g., neighbor side links, neighbor direct links); and / or when the measured CBR / CR is higher than the configured threshold, the WTRU begins performing measurements on adjacent radio links (e.g., measurements of radio conditions on neighbor side links or neighbor direct links). These implementations can be similar to s-measurements, but based on congestion rather than radio signals.

[0234] Based on one or more of the techniques described herein, a WTRU can be configured to operate as a remote WTRU for connection to a base station (e.g., gNB) via a relay WTRU. In one example, the remote WTRU can perform one or more of the following operations: the WTRU receives a measurement configuration related to a sidelink from an NW or relay WTRU; the measurement configuration includes triggering conditions / events for reporting radio conditions of the serving link (e.g., a sidelink or direct link currently serving the WTRU) or neighboring links (e.g., a sidelink or direct link not serving the WTRU); the WTRU performs sidelink / direct link measurements; the WTRU performs CBR / CR measurements; and / or when the triggering conditions are met, the WTRU sends CBR / CR measurement results containing the serving / neighboring sidelink / direct link radio conditions and measurements to the relay WTRU or base station. Triggering conditions may include one or more of the following: sidelink / direct link RSRP / RSRQ / RSNI thresholds; relative offset between the serving link and the neighboring sidelink / direct link; sidelink CBR / CR thresholds; priority of the active sidelink RLC channel; UL pending data thresholds; downlink data reception rate / capacity thresholds; and / or reporting periodicity. These implementations may cover situations where measurements are performed and reported to the base station or relay WTRU, as well as events where serving and neighbor measurements can be compared, taking into account CBR, RLC channel priority, UL / DL data rate / capacity, etc.

[0235] Based on one or more of the techniques described herein, a WTRU can be configured to operate as a relay WTRU for connecting a remote WTRU to a base station (e.g., a gNB). In one example, the relay WTRU may perform one or more of the following operations: the relay WTRU receives a measurement configuration related to a sidelink from a remote NW; the measurement configuration includes triggering conditions / events for reporting radio conditions of the serving link (a sidelink or direct link currently serving the WTRU) or a neighboring link (a sidelink or direct link not serving the WTRU); the relay WTRU performs sidelink RSRP / RSRQ / RSNI measurements or receives measurements from a remote WTRU; the relay WTRU performs measurements on a direct link between the relay WTRU and the base station; the relay WTRU performs CBR / CR measurements; and / or, when a triggering condition is met, the relay WTRU sends CBR / CR measurement results to the base station, including the serving / neighboring sidelink / direct link radio conditions and measurements. Triggering conditions may include one or more of the following: sidelink RSRP / RSRQ / RSNI thresholds; RSRP / RSRQ / RSNI thresholds for the direct link between the relay WTRU and the base station; sidelink CBR / CR thresholds; priority of the active sidelink RLC channel; UL pending data thresholds (e.g., buffered data at the relay WTRU or buffered data at the remote WTRU as reported by the remote WTRU buffer status report); downlink data receive rate / capacity thresholds; and / or reporting periodicity.

[0236] As described herein, a higher layer can refer to one or more layers in a protocol stack, or a specific sublayer within a protocol stack. A protocol stack may include one or more layers in a WTRU or network node (e.g., a base station, other functional entities, etc.), where each layer may have one or more sublayers. Each layer / sublayer may be responsible for one or more functions. Each layer / sublayer may communicate directly or indirectly with one or more other layers / sublayers. In some cases, these layers may be numbered, such as Layer 1, Layer 2, and Layer 3. For example, Layer 3 may include one or more of the following: Non-Access Stratum (NAS), Internet Protocol (IP), and / or Radio Resource Control (RRC). For example, Layer 2 may include one or more of the following: Packet Data Convergence Control (PDCP), Radio Link Control (RLC), and / or Media Access Control (MAC). For example, Layer 3 may include Physical (PHY) layer type operations. The higher the layer number, the higher the layer is relative to other layers (e.g., Layer 3 is higher than Layer 1). In some cases, the foregoing examples may be referred to as the layer / sublayer itself, regardless of the layer number, and may be referred to as a higher layer as described herein. For example, from highest to lowest, a higher layer can refer to one or more of the following layers / sublayers: NAS layer, RRC layer, PDCP layer, RLC layer, MAC layer, and / or PHY layer. Any reference to a higher layer in connection with a process, device, or system herein refers to a layer above that process, device, or system. In some cases, a reference to a higher layer herein may refer to a function or operation performed by one or more layers described herein. In some cases, a reference to a higher layer herein may refer to information sent or received by one or more layers described herein. In some cases, a reference to a higher layer herein may refer to configuration sent and / or received by one or more layers described herein.

[0237] Although features and elements have been described above in specific combinations, those skilled in the art will understand that each feature or element may be used alone or in any combination with other features and elements. As described herein, references to methods, examples, situations, instances, or other such terms are interchangeable and are not intended to be limiting to one or the other. Furthermore, the methods described herein may be implemented in a computer program, 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 a wired or wireless connection) 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), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile optical discs (DVDs)). A processor associated with the software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A method implemented by a wireless transmit / receive unit (WTRU), the method comprising: Configuration information is received by a relay WTRU connected to the WTRU, wherein the configuration information originates from a base station, and wherein the configuration information includes two or more thresholds for measurement reporting of one or more signals, wherein a first threshold is associated with a sidelink reference signal received power (RSRP) measurement, and a second threshold is associated with a sidelink discovery (RSRP) measurement, wherein the one or more signals are one or more sidelink transmissions. Measure the RSRP of the one or more signals; When it is determined that at least one value of one or more RSRP measurements based on the one or more signals satisfies at least one of the first threshold or the second threshold, a measurement report is sent to the base station, wherein the measurement report includes the value of one or more RSRP measurements based on the one or more signals and the measurement type, wherein the measurement type indicates that the value is based on at least one data transmission or at least one discovery signal.

2. The method according to claim 1, wherein, The one or more signals include transmissions from the candidate relay WTRU to the WTRU.

3. The method according to claim 1, wherein, The one or more signals include transmissions from the relay WTRU to the WTRU.

4. The method according to claim 1, wherein, The configuration information also includes Uu RSRP measurement information.

5. The method according to claim 4, further comprising: After sending the measurement report to the base station, an RRCReconfiguration message for switching the WTRU to the direct Uu path is received from the base station.

6. The method according to claim 5, further comprising: After receiving the RRCReconfiguration message, send RRCReconfigurationComplete to the base station.

7. The method according to claim 4, further comprising: Based on the Uu RSRP measurement information, at least one Uu RSRP measurement is sent to the base station.

8. The method according to claim 1, wherein, The measurement report includes the WTRU ID.

9. The method according to claim 1, wherein, The measurement report is sent via the relay WTRU.

10. A wireless transmit / receive unit (WTRU), the WTRU comprising: A processor operably connected to a transceiver, the processor and the transceiver being configured to receive configuration information via a relay WTRU connected to the WTRU, wherein the configuration information originates from a base station, and wherein the configuration information includes two or more thresholds for measurement reporting of one or more signals, wherein a first threshold is associated with a sidelink reference signal received power (RSRP) measurement and a second threshold is associated with a sidelink discovery (RSRP) measurement, wherein the one or more signals are one or more sidelink transmissions; The processor and the transceiver are configured to measure the RSRP of the one or more signals; and When it is determined that at least one value of one or more RSRP measurements based on the one or more signals satisfies at least one of the first threshold or the second threshold, the processor and the transceiver are configured to send a measurement report to the base station, wherein the measurement report includes the value of the one or more RSRP measurements based on the one or more signals and the measurement type, wherein the measurement type indicates that the value is based on at least one data transmission or at least one discovery signal.

11. The WTRU according to claim 10, wherein, The one or more signals include transmissions from the candidate relay WTRU to the WTRU.

12. The WTRU according to claim 10, wherein, The one or more signals include transmissions from the relay WTRU to the WTRU.

13. The WTRU according to claim 10, wherein, The configuration information also includes Uu RSRP measurement information.

14. The WTRU according to claim 13, wherein, The processor and the transceiver are further configured to receive, after sending a measurement report to the base station, an RRCReconfiguration message from the base station for switching the WTRU to a direct Uu path.

15. The WTRU according to claim 14, wherein, The processor and the transceiver are further configured to send RRCReconfigurationComplete to the base station after receiving the RRCReconfiguration message.

16. The WTRU according to claim 13, wherein, The processor and the transceiver are further configured to send at least one Uu RSRP measurement to the base station based on the Uu RSRP measurement information.

17. The WTRU according to claim 10, wherein, The measurement report includes the WTRU ID.

18. The WTRU according to claim 10, wherein, The measurement report is sent via the relay WTRU.

19. A method implemented by a remote wireless transmit / receive unit (WTRU), the method comprising: Receive configuration information, wherein the configuration information is received via a relay WTRU connected to the remote WTRU, wherein the configuration information originates from a base station, wherein the configuration information includes one or more thresholds for measuring the sidelink reference signal received power (RSRP) to trigger a measurement report, wherein a first threshold of the one or more thresholds is associated with a measurement of one or more sidelink discovery signals, and wherein a second threshold of the one or more thresholds is associated with a measurement of one or more sidelink data transmissions. The RSRP measures one or more signals, wherein the one or more signals are one or more sidelink discovery signals or one or more sidelink data transmissions; as well as When it is determined that at least one value of one or more RSRP measurements based on the one or more signals satisfies at least one of the first threshold or the second threshold, a measurement report is sent to the base station, wherein the measurement report includes the value of the one or more RSRP measurements based on the one or more signals and the type of the measurement, wherein the type of the measurement indicates that the value is based on one or more sidelink discovery signals or one or more sidelink data transmissions.

20. The method of claim 19, further comprising: After sending the measurement report to the base station, an RRCReconfiguration message for switching the remote WTRU to the direct Uu path is received from the base station; as well as After receiving the RRCReconfiguration message, send RRCReconfigurationComplete to the base station.

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