Methods, architectures, apparatuses and systems for path switching

Abstract

Procedures, methods, architectures, apparatuses, systems, devices, and computer program products for path switching are disclosed. A wireless transmit-receive unit, WTRU, member of a group of WTRUs for performing a collaborative service, may receive an indication for path switching of traffic between the WTRU and a network. The WTRU may discover candidate WTRU-to-network relays available for handling the traffic between the WTRU and the network. The WTRU may select a candidate WTRU-to-network relay to perform the path switching.

Description

METHODS, ARCHITECTURES, APPARATUSES AND SYSTEMS FOR PATH SWITCHINGCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of US Provisional Patent Application No. 63 / 527,693 filed July 19, 2023, which is incorporated by reference herein in its entirety.BACKGROUND

[0002] The present disclosure is generally directed to the fields of communications, software and encoding, including, for example, to methods, architectures, apparatuses, systems related to collaborative services.SUMMARY

[0003] Aggregating communication (e.g., for improving throughput, coverage) and computing capabilities of multiple WTRUs (Wireless Transmit-Receive Units) when serving a single application and / or a single user, allows systems to provide resources are services that satisfy requirements of such applications.

[0004] Combining capabilities of multiple WTRUs also allows to provide enhanced user experiences.

[0005] A WTRU to Network relay (WTRU2NW relay) provides coverage extension to WTRUs by providing indirect connection to the 5GC (5G Core).

[0006] It would be desirable to define a mechanism to allow the coordination of a group of WTRUs to connect to a WTRU2NW relay, and to avoid disconnection of some WTRUs due to failure to switch to a WTRU2NW relay.

[0007] In the following, there are defined and described methods and apparatuses for improvement of the management of groups of WTRUs that cooperate to provide a service or services, and that are claimed according to the appended claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] A more detailed understanding may be had from the detailed description below, given by way of example in conjunction with drawings appended hereto. Figures in such drawings, like the detailed description, are examples. As such, the Figures (FIGs.) and the detailed description are not to be considered limiting, and other equally effective examples are possible and likely. Furthermore, like reference numerals ("ref.") in the FIGs. indicate like elements, and wherein:

[0009] FIG. 1 A is a system diagram illustrating an example communications system;

[0010] FIG. IB is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1 A;

[0011] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A;

[0012] FIG. ID is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1 A;

[0013] FIG. 2 is a sequence chart of a method for path switching of a group of WTRUs to a WTRU2NW relay according to an embodiment;

[0014] FIG. 3 is a sequence chart of a method for a layer 2 based connection setup of WTRUs of a collaboration group according to an embodiment;

[0015] FIG. 4 is a sequence chart of a method for a layer 3 based connection setup of WTRUs of a collaboration group according to an embodiment;

[0016] FIG. 5 is a sequence chart of a method for a layer 2-based WTRU2NW relay connection setup for a collaboration group according to an embodiment;

[0017] FIG. 6 is a sequence chart of a method for a layer 3-based WTRU2NW relay connection setup for a layer 3 -based collaboration group according to an embodiment;

[0018] FIG. 7 is a sequence chart of a method for WTRU2NW relay connection setup for multimodal service according to an embodiment;

[0019] FIG. 8 is a flow chart of a method of path switching according to an embodiment;

[0020] FIG. 9 is a flow chart of a method for collaborative services according to an embodiment;

[0021] FIG. 10 is a flow chart of a method for path switching for collaborative services according to an embodiment.

[0022] FIG. 11 is a flow chart of a method for path switching for collaborative services according to an embodiment.DETAILED DESCRIPTION

[0023] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components and circuits have not been described in detail, so as not to obscure the following description. Further, embodiments and examples not specifically described herein may be practiced in lieu of,or in combination with, the embodiments and other examples described, disclosed or otherwise provided explicitly, implicitly and / or inherently (collectively "provided") herein. Although various embodiments are described and / or claimed herein in which an apparatus, system, device, etc. and / or any element thereof carries out an operation, process, algorithm, function, etc. and / or any portion thereof, it is to be understood that any embodiments described and / or claimed herein assume that any apparatus, system, device, etc. and / or any element thereof is configured to carry out any operation, process, algorithm, function, etc. and / or any portion thereof.

[0024] Abbreviations and AcronymsAF Application FunctionAMBR Aggregate Maximum Bit RateNAS Non-Access StratumNW NetworkPC5 Interface for direct (device-to-device or WTRU-to-WTRU) communicationsProSe Proximity based ServiceRAT Radio Access TechnologyRAN Radio Access NetworkREQ RequestRRC Radio Resource ControlRSP ResponseUE User Equipment, WTRUWTRU2NW WTRU -to-network w / with

[0025] Example Communications System

[0026] The methods, apparatuses and systems provided herein are well-suited for communications involving both wired and wireless networks. An overview of various types of wireless devices and infrastructure is provided with respect to FIGs. 1A-1D, where various elements of the network may utilize, perform, be arranged in accordance with and / or be adapted and / or configured for the methods, apparatuses and systems provided herein.

[0027] FIG. 1A is a system diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), singlecarrier FDMA (SC-FDMA), zero-tail (ZT) unique-word (UW) discreet Fourier transform (DFT)spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block- filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0028] As shown in FIG. 1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104 / 113, a core network (CN) 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a "station" and / or a "STA", may be configured to transmit and / or receive wireless signals and may include (or be) a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi- Fi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE.

[0029] The communications systems 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d, e.g., to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or the networks 112. By way of example, the base stations 114a, 114b may be any of a base transceiver station (BTS), a Node-B (NB), an eNode-B (eNB), a Home Node-B (HNB), a Home eNode-B (HeNB), a gNode-B (gNB), a NR Node-B (NR NB), a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0030] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may providecoverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in an embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each or any sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0031] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0032] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA) and / or High-Speed Uplink Packet Access (HSUPA).

[0033] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE- Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0034] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access, which may establish the air interface 116 using New Radio (NR).

[0035] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., an eNB and a gNB).

[0036] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (Wi-Fi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 IX, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0037] The base station 114b in FIG. 1 A may be a wireless router, Home Node-B, Home eNode- B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish any of a small cell, picocell or femtocell. As shown in FIG. 1 A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0038] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 1 A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may be utilizing an NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing any of a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

[0039] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 114 or a different RAT.

[0040] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0041] FIG. IB is a system diagram illustrating an example WTRU 102. As shown in FIG. IB, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other elements / peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0042] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. IB depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together, e.g., in an electronic package or chip.

[0043] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in an embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detectorconfigured to transmit and / or receive IR, UV, or visible light signals, for example. In an embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0044] Although the transmit / receive element 122 is depicted in FIG. IB as a single element, the WTRU 102 may include any number of transmit / receive elements 122. For example, the WTRU 102 may employ MIMO technology. Thus, in an embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0045] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0046] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), readonly memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

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

[0048] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., basestations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0049] The processor 118 may further be coupled to other elements / peripherals 138, which may include one or more software and / or hardware modules / units that provide additional features, functionality and / or wired or wireless connectivity. For example, the elements / peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (e.g., for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, and the like. The elements / peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0050] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the uplink (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and / or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the uplink (e.g., for transmission) or the downlink (e.g., for reception)).

[0051] FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0052] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, forexample, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.

[0053] Each of the eNode-Bs 160a, 160b, and 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink (UL) and / or downlink (DL), and the like. As shown in FIG. 1C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0054] The CN 106 shown in FIG. 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any one of these elements may be owned and / or operated by an entity other than the CN operator.

[0055] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an SI interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0056] The SGW 164 may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via the SI interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter-eNode-B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0057] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0058] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0059] Although the WTRU is described in FIGs. 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

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

[0061] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic into and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to-peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802. l ie DLS or an 802.1 Iz tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an "ad-hoc" mode of communication.

[0062] When using the 802.1 lac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier sense multiple access with collision avoidance (CSMA / CA) may be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0063] High throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadj acent 20 MHz channel to form a 40 MHz wide channel.

[0064] Very high throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse fast fourier transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above-described operation for the 80+80 configuration may be reversed, and the combined data may be sent to a medium access control (MAC) layer, entity, etc.

[0065] Sub 1 GHz modes of operation are supported by 802.1 laf and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.1 laf and 802.1 lah relative to those used in802.1 In, and 802.1 lac. 802.1 laf supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV white space (TVWS) spectrum, and 802.1 lah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment,802.1 lah may support meter type control / machine-type communications (MTC), such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0066] WLAN systems, which may support multiple channels, and channel bandwidths, such as802.1 In, 802.1 lac, 802.1 laf, and 802.1 lah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.1 lah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0067] In the United States, the available frequency bands, which may be used by 802.1 lah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.1 lah is 6 MHz to 26 MHz depending on the country code.

[0068] FIG. ID is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0069] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from the WTRUs 102a, 102b, 102c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0070] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., including a varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0071] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate withone or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non- standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0072] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, and the like. As shown in FIG. ID, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0073] The CN 115 shown in FIG. ID may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and at least one Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0074] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b, e.g., to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for MTC access, and / or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0075] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policyenforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP -based, non-IP based, Ethernet-based, and the like.

[0076] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, e.g., to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multihomed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0077] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In an embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0078] In view of FIGs. 1 A-1D, and the corresponding description of FIGs. 1 A-1D, one or more, or all, of the functions described herein with regard to any of: WTRUs 102a-d, base stations 114a- b, eNode-Bs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a- b, SMFs 183a-b, DNs 185a-b, and / or any other element(s) / device(s) described herein, may be performed by one or more emulation elements / devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0079] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or may performing testing using over-the-air wireless communications.

[0080] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0081] Introduction

[0082] 5G ProSe

[0083] The 5G ProSe service is for direct discovery of available WTRU to WTRU network connection, for direct communication between WTRUs, for providing coverage extension to network via relay connection, and for coverage extension between WTRUs via relays.

[0084] For direct communication between WTRUs, broadcast communication, multicast communication and unicast communication are possible.

[0085] Device-to-Device (D2D) direct communication enables two devices to communicate directly between them with or without the aid of the network. For unicast communication, communicating entities use Layer-2 IDs (identifiers) for uniquely identifying the WTRUs. An application Layer ID may be associated with one or more ProSe applications within the same WTRU, while in scenarios where the WTRU has more than one application layer ID, each Application Layer ID of the same WTRU is seen as a different WTRU. Group Communication mechanism allows one-to-many communication among WTRUs in a highly resource efficient manner, allowing messages to be disseminated easily to a large group of people, over a common downlink stream.

[0086] A WTRU to Network relay (WTRU2NW relay) provides coverage extension to WTRUs by providing indirect connection to the 5GC (5G Core) via layer 2 relay and via layer 3 relay. When a WTRU connects to the layer2 WTRU2NW relay, the gNB is aware that the WTRU is connected via layer 2 WTRU2NW relay. When a WTRU connects to the layer3 WTRU2NW relay, the WTRU2NW relay informs the 5GC that the WTRU connected to the relay.

[0087] A WTRU to WTRU relay (WTRU2WTRU relay) provides extension of communication between WTRUs via layer 2 relays and via layer 3 relays. When a WTRU connects to the layer 2 WTRU2WTRU relay, the layer 2 relay just forwards traffic between two WTRUs, and two WTRUs handle end to end connection between them. When a WTRU connects to the layer 3 WTRU2WTRU relay, the layer 3 relay forwards packet of WTRU based layer 3 address.

[0088] By using the 5G ProSe service, a WTRU may have multiple connections via direct connection to the 5GC and indirect connection via a relay to the 5GC at the same time.

[0089] WTRU Aggregation

[0090] Given the increased bandwidth and processing requirements of emerging applications such as for XR / Metaverse, one way to satisfy those requirements is to aggregate resources of more than one device. Aggregating communication (e.g., for improving throughput, coverage) and computing capabilities of multiple WTRUs when serving a single application and / or a single user, allows systems to provide resources are services that satisfy requirements of such applications.

[0091] Combining capabilities of multiple WTRUs also allows to provide enhanced user experiences. For example, instead of providing an application experience using a single WTRU (that is rather limiting due to various factors such as the form factor, limited battery life), where audio, video and haptic information are presented to the user, the audio, video, and haptic information may be presented to the user by aggregating a VR headset, headphones, and a haptic suit, for the same application and the user, making the application experiences truly immersive.

[0092] Overview

[0093] WTRUs in a group may make a path switch to a same WTRU2NW relay without impacting service experience

[0094] For some applications (e.g., video game, public safety, XR, or users in a car), there may be a group of WTRUs for some applications at a same location. And WTRUs in that group may change to indirect connection of a WTRU2NW Relay for many reasons (e.g., mobility, gNB overloading, etc.).

[0095] In conventional 5G ProSe technology, there is no mechanism defined among WTRUs and WTRU2NW Relay to allow the coordination of a group of WTRUs to connect to a WTRU2NW Relay.

[0096] Without proper support for coordination among WTRUs and WTRU2NW Relay(s), some of the WTRUs may be disconnected due to failure to switch to a WTRU2NW relay or may take a longer delay than others to find another available WTRU2NW relay. This will impact quality of service of group of WTRUs. For example, if some sensors (sensors of the group of WTRUs, e.g., referring to the previously mentioned example of a VR headset, headphones, and haptic suit) are not available for rendering a multimodal service to a user, the service may be disabled or QoE (Quality of Experience) of the user may be degraded because of lack of functionality (e.g., delayed interaction, wrong / stale location information, etc.).

[0097] Therefore, according to embodiments, for WTRUs in a group that may make a path switch to a same WTRU2NW relay without impacting service experience:-for WTRUs in a group, path switching to a WTRU2NW Relay is triggered and an initiating WTRU is selected;-the initiating WTRU discovers and selects a WTRU2NW Relay and negotiates path switching of WTRUs in the group with the selected WTRU2NW Relay;-the initiating WTRU informs the other WTRUs in the group of the information about the WTRU2NW Relay; and-the initiating WTRU and the other WTRUs in the group connect to the selected WTRU2NW Relay.

[0098] Therefore, according to embodiments, for WTRUs in a group that may make a path switch to a same WTRU2NW relay without impacting service experience, a WTRU2NW Relay: -announces an RSC to support a group of WTRUs;-negotiates possible support of connection setup of a group of WTRUs with an initiating WTRU; -reserves some resources for connection and PDU session support for WTRUs in the group; and -establishes a ProSe connection for each WTRU in the group.

[0099] Figure 2 is a sequence chart of a method for path switching of a group of WTRUs to a WTRU2NW relay according to an embodiment.

[0100] At the top, from left to right, are depicted: WTRU1 (2001), WTRU2 (2002), WTRU3 (2003), WTRU2NW relayl (2011), WTRU2NW relay2 (2012), and WTRU2NW relay3 (2013).

[0101] It is assumed that the three depicted WTRUs (here WTRU1, WTRU2, and WTRU3) belong to a group (e.g., a group of WTRUs used in an XR application, a group of WTRUs used in a collaborative service, etc.).

[0102] In 200, a WTRU member of the WTRU group (here WTRU1) is triggered about path switching to a WTRU2NW Relay for one or several reasons (e.g., bad channel quality, bad data rate, bad packet error rate, etc.).

[0103] As another example, when WTRUs in a group are served by a WTRU2NW Relay WTRU, the relay WTRU may trigger the group mobility when the relay cannot handle the resources for the whole WTRU group.

[0104] As another example, an application or application server may trigger group mobility to path switch to a WTRU2NW Relay when some of the WTRU group members are experiencing a drop of QoS.

[0105] For the WTRU group, an application group ID may be assigned by Application and / or a Layer2 group ID for addressing the WTRU group for PC5 communication (device-to-device (WTRU -to- WTRU) communication based on sidelink, that does not require the presence of a base station (gNB)) may be assigned by 5GC. Each WTRU in the group may be informed by theapplication about the group member WTRUs (e.g., user info of WTRUs) and about the number of group member WTRUs. Here, group ID means application group ID.

[0106] In 201 : WTRU1 may share its status (e.g., bad channel quality, bad data rate, etc.) via groupcast or unicast and the need for path switching to a WTRU2NW relay with other WTRUs in the group. Each WTRU in the group may respond to WTRU1 when WTRU1 shares its status.

[0107] WTRU 1 may create a group member list from the WTRUs responding to the information sharing in step 201 and may set a number of WTRU group member WTRUs based on a number of responding WTRUs in step 201. Alternatively, any WTRU that has poor QoS may negotiate with other WTRUs and some WTRUs may be selected as an initiating WTRU to perform relay discovery (here, WTRU1 is selected as an initiating WTRU) or the application may select the initiating WTRU to perform relay discovery based on its capabilities such as processing power and battery etc.

[0108] In 202, WTRU1 performs a discovery procedure to discover an available WTRU2NW Relay for the group.

[0109] The other WTRUs in the group may perform a discovery procedure to discover available WTRU2NW Relay for the group.

[0110] A RSC (relay service code) may be assigned per ProSe service supporting group of WTRUs and WTRUs in the group may discover WTRU2NW Relays supporting RSC.

[0111] When the group is formed for a specific service (e.g., collaborative service), dedicated RSC(s) may be assigned for supporting the specific service. The WTRUs in the group may discover a WTRU2NW Relay supporting the specific services via the dedicated RSC(s).

[0112] A WTRU may include the number of WTRUs in the group that will need to access a relay in the discovery request message for model B discovery mode. According to well-known concepts in ProSe, in Model B (“are you there?”) an initiating (discoverer) WTRU sends a solicitation request message. The responding (discoveree) WTRU sends a solicitation response message to be discovered. In Model A (“I am here”) an initiating (announcing) WTRU sends an announcing message to be discovered. Model A uses a single discovery protocol message (Announcement): Relay sends an Announcement message periodically. Model B uses two discovery protocol messages (Solicitation and Response): WTRU sends a Solicitation message and the Relay replies with a Response message.

[0113] A relay may inform a number of WTRUs which may be allowed to access the relay in a discovery response message for model B discovery mode or in an announcement message for model A discovery mode.

[0114] In 203, WTRU1 and other WTRUs may exchange information about discovered WTRU2NW Relays such as Relay IDs, supported services and associated RSC, and number ofsupported WTRUs to access the relay. A candidate WTRU2NW Relay may be selected, e.g., a common Relay that is available to all WTRU group members.

[0115] For example, when WTRU1 and the other WTRUs in the WTRU group have performed a discovery procedure, a Relay, which is discovered by every WTRUs in the group, may be selected (here Relay 1).

[0116] In 204, WTRU 1 sends a PC5 connection setup request to the selected WTRU2NW Relay which includes an indication of group mobility. The connection setup request may include the number of WTRUs in the group which is acquired as described in step 200 and step 201.

[0117] In 205, WTRU1 and WTRU2NW Relay may setup the security for the connection. After the security for the connection is setup, WTRU1 may provide WTRU’s information related to the group and / or group ID to the WTRU2NW relay. WTRU1 sends group related information to the WTRU2NW relay but does that only once the link is secured so that the group related information cannot be eavesdropped. Step 205 includes 2 messages: the WTRU2NW relay sends a Direct Security Mode Command (DSM) to WTRU1. WTRU1 replies with a DSM Complete message, which may include group information. The DSM Complete message is secured, i.e., integrity / replay protected and encrypted.

[0118] In 206, when the relay accepts the request from WTRU1 sent in 204, it returns a PC5 connection setup response.

[0119] When the relay accepts the group of WTRUs, the relay may reserve resources for the group of WTRUs and the response message may include a resource ID of the reserved resource (Reserved Resource ID) to indicate the resource for the group of WTRUs.

[0120] When the relay received a group ID in step 204 or in step 205, the relay may include group ID in the message sent in 206.

[0121] In 207 : After having received the PC5 connection setup response, WTRU 1 may share the result with other WTRUs in the group and the WTRU2NW relay information (e.g., WTRU2NW relay user info, discovered WTRU2NW relay L2 ID, etc.). WTRU1 may share reserved resource ID with other WTRUs.

[0122] In 208 : other WTRUs in the group send a PC5 connection setup request to the relay which includes the Reserved Resource ID.

[0123] Alternatively, the Reserved Resource ID may be shared after the security for the connection is established between the WTRU and the relay.

[0124] In 209, when the relay receives a PC5 connection setup request that includes a Reserved Resource ID, the relay checks whether the WTRU belongs to WTRUl’s group of WTRUs. If so, the WTRU is allowed to access, and the relay may accept the request from the WTRU, and the relay returns a PC5 connection setup response to the WTRU.

[0125] Additionally, or alternatively, the relay may assign a temporary group ID for the WTRUs in the group. When a temporary group ID is assigned by the relay and a temporary group ID is included in the PC5 setup response to the WTRU1, the temporary group ID may be shared with other WTRUs and other WTRUs in the group may subsequently include the temporary group ID in the PC5 setup request to the relay.

[0126] Alternatively, for path switching of a group of WTRUs, instead of all group members switching to a same WTRU2NW relay, the path switching may be to multiple WTRU2NW relays.

[0127] For example, a group of WTRUs may not be moved to a WTRU2NW Relay (e.g. in step 203, there may be no WTRU2NW Relay discovered to support the requested number of WTRUs or a WTRU2NW relay may reject the PC5 setup request in step 208 because of lack of resources (e.g., the WTRU2NW relay reached its limit / congestion / can’t ensure QoS), or alternatively, a WTRU2NW relay may inform its status to WTRUs in the WTRU group that the WTRU2NW relay has not enough resources to support more WTRUs) or the WTRU2NW relay rejects only additional WTRUs or the WTRU2NW relay disconnects from the whole group and requests / informs the WTRU group members to move to a different relay; e.g., providing a cause code or rejection code, indicating an impossibility to serve connectivity for the group; the WTRUs in the WTRU group determine, based on the cause / rej ection code, to initiate selection of an alternative WTRU2NW relay.

[0128] When a group of WTRUs cannot move to a WTRU2NW Relay, a new / different WTRU2NW relay may be discovered to support all WTRUs that are members of the group and subsequently the WTRUs may move to the newly discovered relay WTRU.

[0129] Alternatively, when a group of WTRUs cannot move to a WTRU2NW relay, multiple WTRU2NW relays may be used (e.g., in step 203, multiple WTRU2NW relays may be selected to support a group of WTRUs). As another example, when a relay WTRU rejects a PC5 setup request in step 208 or when a relay WTRU informs a WTRU that it has lack of resources to support more WTRUs, a new / different relay WTRU may be discovered by performing steps 201, step 202, and / or step 203.

[0130] When multiple WTRU2NW Relays are used, WTRU group members may negotiate among them which WTRU group member will join which WTRU2NW Relay, or when an additional WTRU2NW Relay is discovered, remaining member WTRUs may move to the discovered additional WTRU2NW Relay by individually performing steps 207-209.

[0131] When a group of WTRUs are connected to multiple WTRU2NW Relays, an application or application server may be provided with associated information (e.g., which member WTRU is attached to (associated with) which WTRU2NW relay WTRU, including the member WTRU’s info and the relay WTRU’s info.). The application server may communicate with the 5GC tocoordinate the traffic of the WTRU group via multiple WTRU2NW Relays for some QoS requirements (e.g., to operate delay adjustments between link via different WTRU2NW relays, to operate bandwidth adjustments per link via a WTRU2NW relay).

[0132] A WTRU may get help from other WTRUs for enhancing downlink or uplink performance

[0133] There are many services and applications which require high data rate for uplink and downlink to support some level of quality of service (e.g., interactive game, XR services, video conferencing, etc.). Even in a 5G system, there are still limitations in terms of coverage where a WTRU may not be able to enjoy such a service that consumes high bandwidth.

[0134] To overcome this limitation, collaborative operation of multiple WTRUs may be considered in order to send and to receive packets with a high data rate. Collaborative operation of multiple WTRUs requires not only coordinated communication among the WTRUs involved in the collaborative operation but also understanding the collaborative operation and handling the packets in the system.

[0135] Therefore, mechanisms to enable collaborative operation among multiple WTRUs and the system are desirable to be able to control the collaborative operation among the multiple WTRUs.

[0136] In an embodiment related to connection setup for a Layer2 -based Collaboration group, a WTRU:-discovers other WTRUs to help enhancement of its connections with 5GC;-establishes ProSe connections with the selected other WTRUs and forms a Collaboration group;-the WTRU, and other WTRUs in the Collaboration group, inform(s) gNBs that the connection of each WTRU in the Collaboration group is for the traffic of the WTRU; and-when a WTRU of the collaboration group is connected to another gNB which is not termination point, the WTRU is handed over to the gNB which is the termination point of the Collaboration group.

[0137] A collaborative service (collaboration service) is a service enhancing a target WTRU’s performance or coverage with 5GC with the aid of other WTRUs (assistance WTRUs) which transmit and receive at least part of the target WTRU’s traffic with the network. The target WTRU and the assistance WTRUs form a collaboration group (collaborative group, allocation group) that support the target WTRU’s collaborative service. The target WTRU may also be referred to as a ‘consumer’ WTRU.

[0138] When a collaborative service is supported by 5GC and WTRUs are subscribed for a collaborative service with service provider, WTRUs need to be authorized for the collaborative services as target WTRU or as assistance WTRU.

[0139] When a WTRU is authorized as a target WTRU for a collaborative service, a collaboration group ID (allocation group ID, i.e., Collaboration Group ID) for the collaborative service for the WTRU may be assigned from 5GC or from an application server. The 5GC may assign a collaboration group ID in coordination with the application server (e.g., the application server may inform the assigned Collaboration group ID for the WTRU to the 5GC).

[0140] When a WTRU is authorized for a collaborative service for multiple application services, the WTRU may be assigned different Collaboration group IDs per application.

[0141] A collaboration group ID may be used as an Application group ID for a ProSe service.

[0142] Additionally, or alternatively, when a WTRU is authorized as a target WTRU for a collaborative service, a Layer2 group ID may be assigned by the 5GC. The WTRU may use Layer2 group ID with an associated indication for support of collaborative service (i.e., an indication that a collaborative service is used).

[0143] A collaborative service may be a Layer2 -based collaborative service or a Layer3-based collaborative service.

[0144] For a Lay er2 -based collaborative service, traffic of a collaboration group for the collaborative service is terminated at a gNB.

[0145] For a Lay er3 -based collaborative service, traffic of a collaboration group for a collaborative service is terminated at an UPF or at an application server.

[0146] Figure 3 is a sequence chart of a method for a layer 2 based connection setup of WTRUs using a collaboration group according to an embodiment. From top left to right are depicted WTRU1 (3001), WTRU2 (3002), WTRU3 (3003), gNBl (3011), gNB2 (3012), AMF (3021) and SMF (3022). It is noted that steps 304-305 are for notifying the 5GC that a collaboration group is initiated, that steps 306a-310a are related to RRC update for the collaboration group for WTRU2, and that steps 306b-312b are related to RRC update for collaboration group for WTRU3 and is similar to the RRC update for collaboration group for WTRU2 in steps 306a-310a but further depicts a handover procedure to redirect a WTRU to the same network node which is serving the WTRUs in the collaboration group, i.e., WTRU1 and WTRU2.

[0147] In 300, WTRU1, WTRU2, WTRU3 are authorized for collaborative services as target WTRU and / or as assistance WTRU of a layer2-based collaborative service. WTRU1 and WTRU2 are served by gNBl and WTRU3 is served by gNB2. WTRU1, WTRU2, WTRU3 are provisioned with policy and parameters for the collaborative service (e.g., WTRU1 may be provided with Collaboration Group ID and Layer2 group ID for the authorized collaborative service; WTRU1, WTRU2, and WTRU3 may be provisioned with a ProSe Discovery Code dedicated to the collaborative service and associated PDU session parameters for the collaborative service and RSCassociated with the collaborative service for discovery of WTRU2NW Relay for the collaborative service).

[0148] In 301, WTRU1 may be triggered by an application or by WTRU internal logic or by an application server to initiate a collaborative (collaboration) group (e.g., for better service experience or for better coverage).

[0149] In 302, WTRU1 discovers other WTRUs (i.e., Assistance WTRUs) that may aid to enhance its connections with the 5GC. During the discovery, WTRU1 may include an indication that it requests a collaborative service (e.g., any indicator for collaborative service requested, ID or RSC associated with the collaborative service or a ProSe Discovery Code dedicated to collaborative service, DNN, etc.). The WTRU1 may indicate that WTRUs supporting Assistance WTRU is wanted during discovery.

[0150] In 303, WTRU2 and WTRU3 reply to the discovery request from WTRU1. The reply may include an indication that these WTRUs support the collaborative service as assistance WTRUs.

[0151] In 304, WTRU1 may inform its serving network node (here, gNBl) of the initiation of a collaborative group. For example, WTRU1 may therefore send a RRC update request to gNBl with an indication of a collaborative group and indication of the assigned Collaboration Group ID (i.e., collaboration group ID) to be used for the initiated collaborative group. WTRU1 may indicate to gNBl that WTRU1 is the target WTRU for the Collaboration group.

[0152] Unless a collaboration Group ID is assigned by the 5GC or by an application server, WTRU1, as target WTRU, may assign a collaboration Group ID.

[0153] Alternatively, a collaboration Group ID may be assigned by a gNB and shared at step 305 (here, by gNBl).

[0154] In 305, when a network node receives an RRC update request for a collaborative group, the network node may send an RRC update response with an indication whether the RRC update request is accepted or not. If accepted, the network node (here gNBl) may associate WTRU1 with a collaboration Group ID.

[0155] In 306a, WTRU1 sends a PC5 setup request to WTRU2. The PC5 setup request may include an indication of a collaborative group and the assigned Collaboration Group ID. WTRU1 may include a Layer2 group ID if such group ID is provisioned at step 300.

[0156] In 307a, WTRU2 sends a PC5 setup response with an indication whether the PC5 setup request is accepted or not.

[0157] In 308a, WTRU2 sends an RRC update request to network node gNBl (which is WTRU2’s serving network node) for establishing an RRC connection for the collaborative group with Collaboration Group ID. WTRU2 may indicate to network node gNBl that WTRU2 is anAssistance WTRU for the Collaboration group. WTRU2 may indicate to the network node that WTRU1 is a target WTRU of the Collaboration group.

[0158] In 309a, when network node gNBl receives an RRC update request for a collaborative group, the gNB may check the authorization information of the WTRU whether the WTRU is authorized or not for the collaborative group. Network node gNBl may send an RRC update response with an indication whether the WTRU is authorized or not.

[0159] When receiving the RRC update request for the collaboration group, network node gNB 1 may update its list of WTRUs associated with the collaborative group. Here, network node gNBl associates WTRU2 and WTRU1 with Collaboration Group ID.

[0160] In 310a, WTRU2 may send confirmation of RRC setup for a collaborative group to WTRU1 to inform that an RRC connection for the collaborative group from WTRU2 is successfully setup.

[0161] In 306b, WTRU1 may send a PC5 setup request to WTRU3. The PC5 setup request may include an indication of the collaborative group and the assigned Collaboration Group ID. WTRU1 may include a Layer2 group ID if it is provisioned at step 300.

[0162] In 307b, WTRU3 sends a PC5 setup response with an indication whether the PC5 setup request is accepted or not.

[0163] In 308b, WTRU3 sends an RRC update request to network node gNB2 (which is WTRU3’s serving network node) for establishing an RRC connection for the collaborative group with Collaboration Group ID. WTRU3 may indicate to gNB2 that WTRU3 is an Assistance WTRU for the Collaboration group. WTRU3 may indicate to gNB2 that WTRU1 is a target WTRU of the Collaboration group.

[0164] In 309b, when receiving an RRC update request for a collaborative group, network node gNB2 may check the authorization information of the WTRU, to verify whether the WTRU is authorized or not for the collaborative group. Network node gNB2 may send an RRC update response with an indication whether it is authorized or not.

[0165] In 310b, when network node gNB2 is aware that the requested collaborative group is served by another network node as a termination point of packets for the collaborative group (here network node gNBl), network node gNB2 may initiate handover procedure for WTRU3 between network nodes gNBl and gNB2.

[0166] When handover is initiated, gNB2 may inform that handover is triggered (e.g., by including an indication in step 309b).

[0167] In 31 lb, after a successful handover procedure, WTRU3 is handed over to network node gNBl.

[0168] In 312b, WTRU3 may send a confirmation of RRC setup for a collaborative group to WTRU1 to inform WTRU1 that an RRC connection for the collaborative group from WTRU3 is successfully setup.

[0169] In 31 lb, if the handover fails, WTRU3 may be dropped from the collaborative group, and WTRU1 is informed that WTRU3 handover has failed and / or that WTRU3 is dropped from the collaborative group. When handover fails, WTRU3’s RRC connections with network node gNB2 for the collaborative group are released. In another embodiment, when a WTRU is dropped from the collaborative group, WTRU1 may repeat the discovery steps to find another WTRU as assistance WTRU for the collaborative group.

[0170] In another embodiment, when a new UEx is discovered that wants to be part of the same collaborative group, that UEx may receive Collaboration Group ID from WTRU1, and UEx may then use the received Collaboration Group ID to receive updated RRC configurations.

[0171] Now turning to embodiments related to connection setup for a Layer3-based Collaboration group, a WTRU may, according to an embodiment:- discover other WTRUs to help enhancement of its connections with the 5GC;- establish ProSe connections with the selected other WTRUs and forms a Collaboration group; and-the WTRU, and other WTRUs in the Collaboration group, may request PDU session setup for traffic of the Collaboration group.

[0172] In the embodiment related to connection setup for a Layer3-based Collaboration group, a SMF may, according to an embodiment:- be informed about PDU session of each WTRU in a collaboration group during PDU session setup; and- determine the PDU session and may inform the UPF (termination point) of this new collaboration group.

[0173] Figure 4 is a sequence chart of a method for a layer3-based connection setup of WTRUs of a collaboration group according to an embodiment.

[0174] Depicted are, from top left to top right, a first WTRU1 (4001), a second WTRU2 (4002), a third WTRU3 (4003), a first network node gNBl (4011), a second network node gNB2 (4012), an AMF (4021) and an SMF (4022). It is noted that steps 404-405 are for notifying the 5GC that a collaboration group is initiated, that steps 406a-410a are related to PDU session setup or modification for the collaboration group for WTRU2, and that steps 406b-41 lb are related to PDU session setup / modification for collaboration group for WTRU3 and is similar to the PDU session setup / modification for collaboration group for WTRU2 in steps 406a-410a but further depicts a handover procedure to redirect a WTRU to a same network node that serves WTRU 1 and WTRU2.

[0175] In 400, WTRU1, WTRU2, WTRU3 are authorized for collaborative services as a target WTRU and / or as assistance WTRUs of layer3 based collaborative group. A layer3-based collaborative group is collaborative group service with traffic from the collaborative group terminating at the UPF or at an Application server. WTRU1 and WTRU2 are served by network node gNBl and WTRU3 is served by network node gNB2.

[0176] In 401, WTRU1 may be triggered by an application or by WTRU internal logic or by an application server to initiate a collaborative group (e.g., for better service experience or for better coverage b).

[0177] In 402, WTRU 1 discovers other WTRUs to help enhancement of its connections with the 5GC. WTRU1 may include a collaborative group indication (e.g., any indicator for collaborative group, ID or RSC associated with the collaborative service or, ProSe Discovery code dedicated to collaborative group, DNN, etc.).

[0178] In 403, WTRU2 and WTRU3 send a response to the discovery request from WTRU 1 with an indication that they support the collaborative group.

[0179] In 404, as part of a notification that a collaboration group is initiated, WTRU 1 may inform the initiation of the collaborative group to 5GC. For example, WTRU1 may send a PDU session modification request with an indication of the collaborative group or the assigned Collaboration Group ID (i.e., collaboration group ID) to be used for the initiated collaborative group. WTRU1 may inform the 5GC that WTRU1 is a target WTRU of the collaborative group. The Collaboration Group ID may be assigned by WTRU, by 5GC when the WTRU is authorized for collaborative group as target WTRU, or by 5GC at the PDU session modification Response in step 405.

[0180] In 405, as part of the notification that a collaboration group is initiated, when having received the PDU session modification request for the collaborative group, the SMF may send a PDU session modification response with indication whether the request is accepted or not.

[0181] In 406a, as part of an RRC update for a collaboration group, WTRU1 may send a PC5 setup request to WTRU2. The PC5 setup request may include an indication of the collaborative group and the assigned Collaboration Group ID.

[0182] In 407a, as part of the RRC update for a collaboration group, WTRU2 may send a PC5 setup response with an indication whether WTRU2 accepts to be part of the collaborative group or not.

[0183] In 408a, as part of the RRC update for the collaboration group, WTRU2 sends a PDU session setup request or a PDU session modification request to the SMF for establishing a PDU session for the collaborative group with Collaboration Group ID. WTRU2 may inform the SMF that WTRU2 is a assistance WTRU of the collaborative group.

[0184] In 409a, as part of the RRC update for the collaboration group, when receiving a PDU session setup request or a PDU session modification request for the collaborative group, the 5GC may check the authorization information of the WTRU, to verify whether the WTRU is authorized or not for the collaborative group. The SMF may send a PDU session setup response or a PDU session modification response with an indication whether the WTRU is authorized or not.

[0185] In 410a, as part of the RRC update for the collaboration group, WTRU2 may send a confirmation of PDU session setup for the collaborative group to WTRU1 to inform WTRU1 that a PDU session for the collaborative group from WTRU2 is successfully setup.

[0186] In 406b, as part of the RRC update for a collaboration group and handover procedure to redirect WTRU to a same serving network node, WTRU1 sends a PC5 setup request to WTRU3. The PC5 setup request may include an indication of the collaboration group and the assigned Collaboration Group ID.

[0187] In 407b, as part of the RRC update for the collaboration group and handover procedure to redirect WTRU to a same serving network node, WTRU3 sends a PC5 setup response with an indication whether it is accepted or not.

[0188] In 408b, as part of the RRC update for the collaboration group and handover procedure to redirect WTRU to a same serving network node, WTRU3 sends a PDU session setup request or a PDU session modification request to the SMF for establishing a PDU session for the collaboration group with Collaboration Group ID. WTRU3 may inform the SMF that WTRU3 is an assistance WTRU of the collaboration group.

[0189] In 409b, as part of the RRC update for the collaboration group and handover procedure to redirect WTRU to a same serving network node, when receiving the PDU session setup request or the PDU session modification request for the collaboration group, the 5GC may check the authorization information of the WTRU, to verify whether it is authorized or not for collaboration group. The SMF may send a PDU session setup response or a PDU session modification response with indication whether it is authorized or not.

[0190] In 410b, as part of the RRC update for the collaboration group and handover procedure to redirect WTRU to a same serving network node, WTRU3 may send a confirmation of PDU session setup for the collaboration group to WTRU 1 to inform WTRU 1 that a PDU session for the collaboration group from WTRU3 is successfully setup.

[0191] In 41 lb, as part of the RRC update for the collaboration group and handover procedure to redirect WTRU to a same serving network node, when the 5GC is aware that WTRUs of a collaboration group are served by multiple gNBs, the 5GC may trigger a handover procedure to move WTRUs of a collaboration group to a serving gNB. For example, when the 5GC is awarethat WTRU3 is served by network node gNB2, WTRU3 may be handed over to network node gNBl for applying WTRU-AMBR for the Collaboration group.

[0192] Maintaining Collaboration Operation among WTRUs when WTRU2NW Relay(s) is (are) involved

[0193] When multiple WTRUs are involved in a collaboration operation, some WTRUs that are member of the collaboration operation group may move to an indirect connection via WTRU2NW Relay(s). It may be desirable to maintain the collaboration operation group be maintained even when some of the collaboration group member WTRUs decide to move to an indirect connection via WTRU2NW Relay.

[0194] Within the context of maintaining a collaboration operation (collaborative service) among WTRUs when WTRU2NW Relay(s) is (are) involved, and according to an embodiment related to path switching to a Layer2 -based WTRU2NW Relay of a WTRU in a collaboration Group, the WTRU:-is triggered to switch to indirect connection via a WTRU2NW Relay;-establishes a relay connection with a selected WTRU2NW Relay;-informs the WTRU2NW Relay of Collaboration Group ID;- the WTRU2NW Relay establishes RRC connection for the WTRU with its serving gNB;-for an L2-based Collaboration group, WTRU2NW Relay provides the Collaboration Group ID together with the WTRU ID to the serving network node;-the WTRU establishes a PDU session via WTRU2NW Relay;-for a L2-based Collaboration group, if a WTRU2NW Relay is attached to another network node different from the termination point, the relay is handed over to the termination point network node of the Collaboration group;-for a L3-based Collaboration group, the WTRU triggers a PDU session setup procedure for the Collaboration group via a WTRU2NW Relay.

[0195] Figure 5 is a sequence chart of a method for a layer 2-based WTRU2NW relay connection setup for a collaboration group according to an embodiment. From top left to top right, are depicted: WTRU1 (5001), WTRU2 (5002), where WTRU1 and WTRU2 are part of a same collaboration group; Layer2 WTRU2NW Relay WTRU (5011), a first network node gNBl (5021), a second network node gNB2 (5031), a PCF (5041) and an UPF (5051).

[0196] In 500, WTRU 1 and WTRU2 are authorized for collaboration services for a layer2 and / or layer3-based collaboration group. WTRU1 and WTRU2 are provisioned with policy and parameters for collaborative services and ProSe services. A layer2 or layer3 based collaboration group of Collaboration Group ID1 (i.e., Collaboration group ID 1) is formed and WTRU1 and WTRU2 belong to the same collaboration group having Collaboration Group ID1.

[0197] In 501 , WTRU2 is triggered for path switching to a WTRU2NW Relay for several reasons (e.g. bad channel quality, bad data rate, bad packet error rate, etc.) and send DCR (i.e. Direct Communication Request) to Relay WTRU. WTRU2 may inform the Relay WTRU that WTRU2 belongs to collaboration group with Collaboration Group ID1.

[0198] In 502, the Relay WTRU accepts the DCR from WTRU2 and sends a DCA (i.e. Direct Communication Accept) to WTRU2.

[0199] In 503, the Relay WTRU sends an RRC update request to gNBl (being the Relay WTRU’s serving gNB) for establishing an RRC connection of WTRU2 via relay WTRU. The Relay WTRU may include WTRU2 information and Collaboration Group ID for the collaboration group in the RRC update request.

[0200] In 504, when receiving an RRC update request for a collaboration group, gNBl may check the authorization information of the WTRU, to verify whether it is authorized or not for the collaboration group. gNBl may send an RRC update response with an indication whether it is accepted or not.

[0201] For a Layer2 based collaborative service, steps 505a and 506a are applied.

[0202] In 505a, when gNBl is aware that the requested collaboration group is served by another gNB as a termination point of packets for the collaboration group (here gNB2), gNBl may initiate a handover procedure for relay WTRU between gNBl and gNB2.

[0203] When handover initiated, gNBl may inform that handover is triggered (e.g., by an indication included in step 504).

[0204] In 506a. after a successful handover procedure, the WTRU2NW relay is handed over to gNB2.

[0205] For a Layer3 based collaborative service, step 505b is applied.

[0206] In 505b, after a connection setup to the layer2 relay, WTRU2 sends a PDU session establishment request for Collaboration Group ID1. The PDU session establishment request may include Collaboration Group ID1 and / or PDU session ID of PDU session for Collaboration Group ID1 which is setup while WTRU2 is served at gNB2. After a successful PDU session setup of WTRU2 via the relay WTRU and gNBl, the PDU session with gNB2 is released.

[0207] Within the context of maintaining a collaboration operation among WTRUs when WTRU2NW Relay(s) is (are) involved, and according to an embodiment related to path switching to a Lay er3 -based WTRU2NW Relay of a WTRU in a Lay er3 -based Collaboration Group, the WTRU:-is triggered to switch to indirect connection via a WTRU2NW Relay;-establishes a relay connection with a selected WTRU2NW Relay;-informs the WTRU2NW Relay of Collaboration Group ID; and-WTRU2NW Relay informs the Collaboration Group ID of the WTRU to the 5GC.

[0208] Within the context of maintaining a collaboration operation among WTRUs when WTRU2NW Relay(s) is (are) involved, and according to the embodiment related to path switching to a Lay er3 -based WTRU2NW Relay of a WTRU in a Lay er3 -based Collaboration Group, the PCF:-updates relaying PDU connection of the WTRU2NW Relay for the WTRU to belonging to Collaboration Group; and-for an L3 Collaboration group, informs SMF the updated packet handling rule so that SMF informs UPF (termination point) the updated packet handling rule for the WTRU’s PDU connection via WTRU2NW Relay.

[0209] Figure 6 is a sequence chart of a method for a layer 3-based WTRU2NW relay connection setup for a layer 3-based collaboration group according to an embodiment. Are depicted, from top left to top right: A collaboration group including a first WTRU1 (6001) and a second WTRU2 (6002), a Layer3 WTRU2NW Relay (6011), an AMF (6021), an SMF (6031), a PCF (6041) and an UPF (6051).

[0210] In 600, WTRU1 and WTRU2 are authorized for collaborative services for a layer3-based collaboration group. WTRU1 and WTRU2 are provisioned with policy and parameters for collaborative services and ProSe services. A layer3 -based collaboration group of Collaboration Group ID1 (i.e., Collaboration group ID 1) is formed and WTRU1 and WTRU2 belong to the collaboration group of Collaboration Group ID1.

[0211] In 601, WTRU2 is triggered for path switching to a Layer3 WTRU2NW Relay. This may be for several reasons, e.g., bad channel quality, bad data rate, bad packet error rate, etc., and WTRU2 sends a DCR (i.e., Direct Communication Request) to the Layer3 WTRU2NW relay. WTRU2 informs the Layer3 WTRU2NW Relay that WTRU2 belongs to Collaboration Group ID1.

[0212] In 602, WTRU2 and Layer3 WTRU2NW Relay may execute a security procedure for setting up a secure connection.

[0213] In 603, the Layer3 WTRU2NW Relay may initiate a PDU session establishment procedure for serving traffic of WTRU2 for the collaborative service.

[0214] In 604, the Layer3 WTRU2NW Relay may respond with DCA to WTRU2.

[0215] In 605, the Layer3 WTRU2NW Relay may send a Remote WTRU Report to the SMF, to inform the SMF that WTRU2 is accessing to Layer3 WTRU2NW relay and WTRU2 belongs to Collaboration Group ID1.

[0216] In 606, the SMF may send a PDU session context update request to the PCF to inform the PCF that WTRU2 is attached to Layer3 WTRU2NW relay and that WTRU2 belongs to Collaboration Group ID1.

[0217] In 607, the PCF updates the PDU session context of Layer3 WTRU2NW Relay accordingly, i.e., associating WTRU2 to Collaboration Group ID1 in the PDU session context.

[0218] In 608, the PCF may send a PDU session context update Response to the SMF for updating a PCC rule for Collaboration Group ID1.

[0219] In 609, the SMF may update the UPF termination point of traffic for the collaboration group of Collaboration Group ID1 with an updated packet handling rule.

[0220] Within the context of maintaining a collaboration operation among WTRUs when WTRU2NW Relay(s) is (are) involved, and according to an embodiment related to path switching of a WTRU to a WTRU2NW Relay for a multimodal XR service, the WTRU:-is triggered to switch to indirect connection via a WTRU2NW Relay;-may inform the AF that the WTRU’s connection is changed to a relay connection and the AF informs this update to the PCF; and-the WTRU2NW Relay informs the WTRU is attached to the WTRU2NW Relay to the 5GC.

[0221] Within the context of maintaining a collaboration operation among WTRUs when WTRU2NW Relay(s) is (are) involved, and according to an embodiment related to path switching of a WTRU to a WTRU2NW Relay for multimodal XR service, the PCF :-the PCF is aware, based on information received from the AF, that the WTRU belongs to a multi modal service ID that is attached to the WTRU2NW Relay;-updates relaying PDU connection of the WTRU2NW Relay for the WTRU to belonging to the multi modal service ID; and-informs the SMF of the updated packet handling rule so that the SMF informs the UPF (termination point) of the updated packet handling rule for the WTRU’s PDU connection via the WTRU2NW Relay.

[0222] Figure 7 is a sequence chart of a method for WTRU2NW relay connection setup for multimodal service according to an embodiment. Are depicted, from top left to top right: a first WTRU1 (7001) and a second WTRU2 (7002), the first and the second WTRU belonging to a same multimodal service, a Layer3 WTRU2NW Relay (7011), an AMF (7021), an SMF (7031), a PCF (7041) an UPF (7051) and an AF (7061).

[0223] In 700, WTRU1 and WTRU2 are authorized for ProSe service and are provisioned with policy and parameters for the ProSe service. WTRU1 and WTRU2 belong to a same multimodal service. The 5GC assigns a multimodal service ID_1 for the multimodal service including WTRU 1 and WTRU2.

[0224] In 701 , WTRU2 is triggered for path switching to a Layer3 WTRU2NW Relay for several reasons, for example bad channel quality, bad data rate, bad packet error rate, etc., and WTRU2 sends a DCR (i.e., Direct Communication Request) to the WTRU2NW Relay.

[0225] In 702, WTRU2 and WTRU2NW Relay execute a security procedure to setup secured communication.

[0226] In 703, the WTRU2NW Relay may initiate a PDU session establishment or a PDU session modification procedure for serving traffic of WTRU2.

[0227] In 704, the WTRU2NW Relay may respond DCA to WTRU2.

[0228] In 705, WTRU2 may inform the AF for multi modal service about WTRU’ s status update, indicating that WTRU2 changed to an indirect connection for WTRU2NW Relay connection.

[0229] In 706, the AF may inform PCF about the WTRU’s status update indicating that WTRU2 changed to an indirect connection for WTRU2NW Relay connection.

[0230] In 707, the WTRU2NW Relay may send a Remote WTRU Report the SMF to inform the SMF that WTRU2 is accessing to WTRU2NW relay.

[0231] In 708,. the SMF sends a PDU session context update request to the PCF to inform the PCF that WTRU2 is attached to the WTRU2NW relay.

[0232] In 709, the PCF detects that WTRU2 that belongs to a multimodal service of multimodal service ID_1 changed its connection to an indirect connection based on AF’s input at step 706 and WTRU2’s info received in step 708.

[0233] In 710, the PCF may update the PDU session context of WTRU2NW Relay and the PDU session context for multimodal service ID_1.

[0234] In 711, the PCF may send a PDU session context update Response to the SMF for updating a PCC rule for multimodal service of multimodal service ID_1.

[0235] In 712, the SMF may update the UPF with an updated packet handling rule of multimodal service of multimodal service ID_1.

[0236] Further in the context of maintaining a collaboration operation among WTRUs when WTRU2NW Relay(s) is (are) involved, and according to an embodiment related to path switching of a WTRU to a WTRU2NW Relay for multimodal XR service, WTRUs may be added to the multimodal XR service via WTRU2NW relay.

[0237] A WTRU may join a multimodal XR service via indirect connection when direct connection is not available by performing step 701, step 702, step 703, and step 704.

[0238] After connection to the multimodal XR service via the WTRU2NW relay, the application server may detect that new collaboration operation service members joined and may perform step 706, and include an indication that (a) new WTRU(s) joined the multimodal service via an WTRU2NW relay with new WTRU’s information.

[0239] When receiving the status update 706 from the AF, the PCF may perform steps 709 and following steps 710 to 712 are also performed.

[0240] Figure 8 is a method implemented by a wireless transmit-receive unit, WTRU, according to an embodiment. The method may comprise:

[0241] receiving (800) a first message comprising an indication for path switching for at least some traffic between the WTRU and a network, the WTRU being a member of a group of WTRUs;

[0242] sending (801) a second message to the other members of the group of WTRUs, the second message comprising the indication;

[0243] discovering (802) at least one first candidate WTRU-to-network relay available for handling traffic between the WTRUs of the WTRU group and the network;

[0244] receiving (803) indications from the other members of the group of WTRUs related to discovery of at least one second candidate WTRU-to-network relay available for handling traffic between the WTRUs of the WTRU group and the network;

[0245] selecting (804), from the at least one first and the at least one second candidate WTRU- to-network relay, a WTRU-to-network relay for handling traffic between the WTRUs of the WTRU group and the network; and

[0246] path switching (805) of the at least some traffic between the WTRU and the network via the selected WTRU-to-network relay.

[0247] According to an embodiment, the selected WTRU-to-network relay is common between the at least one first and the at least one second candidate WTRU-to-network relays.

[0248] According to an embodiment, the first message is received from one of

[0249] an application or an application server;

[0250] a WTRU-to-network relay handling the at least some traffic between the WTRU and the network.

[0251] According to an embodiment, the first message is triggered by the application or the application server based on a group mobility for members of the group of WTRUs due to at least one member in the group of WTRUs experiencing a quality of service drop.

[0252] According to an embodiment, the first message is triggered by the WTRU-to-network relay handling the at least some traffic between the WTRU and the network, due to the WTRU-to- network relay handling the at least some traffic between the WTRU and the network not having enough resources to handle traffic between members of the group of WTRUs and the network.

[0253] According to an embodiment, the group of WTRUs is formed for a collaborative service, the at least one first and at least one second candidate WTRU-to-network relays supporting the collaborative service.

[0254] There is also disclosed and described a wireless transmit-receive unit, WTRU, comprising at least one processor, the at least one processor being configured to, according to an embodiment:

[0255] receive a first message comprising an indication for path switching for at least some traffic between the WTRU and a network, the WTRU being a member of a group of WTRUs;

[0256] send a second message to the other members of the group of WTRUs, the second message comprising the indication;

[0257] discover at least one first candidate WTRU-to-network relay available for handling traffic between the WTRUs of the WTRU group and the network;

[0258] receive indications from the other members of the group of WTRUs related to discovery of at least one second candidate WTRU-to-network relay available for handling traffic between the WTRUs of the WTRU group and the network;

[0259] select, from the at least one first and the at least one second candidate WTRU-to- network relay, a WTRU-to-network relay for handling traffic between the WTRUs of the WTRU group and the network; and

[0260] switch path of the at least some traffic between the WTRU and the network via the selected WTRU-to-network relay.

[0261] According to an embodiment of the WTRU, the at least one processor is configured to select a WTRU-to-network relay is common between the at least one first and the at least one second candidate WTRU-to-network relays.

[0262] According to an embodiment of the WTRU, the at least one processor is configured to receive the first message from one of

[0263] an application or an application server;

[0264] a WTRU-to-network relay handling the at least some traffic between the WTRU and the network.

[0265] According to an embodiment of the WTRU, the first message is triggered by the application or the application server based on a group mobility for members of the group of WTRUs due to at least one member in the group of WTRUs experiencing a quality of service drop.

[0266] According to an embodiment of the WTRU, the first message is triggered by the WTRU- to-network relay handling the at least some traffic between the WTRU and the network, due to the WTRU-to-network relay handling the at least some traffic between the WTRU and the network not having enough resources to handle traffic between members of the group of WTRUs and the network.

[0267] According to an embodiment of the WTRU, the group of WTRUs is formed for a collaborative service, the at least one first and at least one second candidate WTRU-to-network relays supporting the collaborative service.

[0268] Figure 9 is a method, implemented by a wireless transmit-receive unit, WTRU according to an embodiment. The method comprising:

[0269] receiving (900) configuration information for setting up a collaborative service;

[0270] Receiving (901) a first indication to initiate a collaboration group of WTRUs for realizing the collaborative service, based on the received configuration information;

[0271] Sending (902) discovery requests to other WTRUs for assistance of the WTRU in the collaboration group to realize the collaborative service for the WTRU;

[0272] receiving (903) responses to the discovery requests from at least one of the other WTRUs, indicating support for assistance of the WTRU in the collaboration group;

[0273] sending (904) a second indication of the initiation of the collaboration group to a network node serving the WTRU, the second indication comprising information relative to WTRUs selected from the at least one of the other WTRUs that indicated support for assistance of the WTRU in the collaboration group; and

[0274] setting up (905) device-to-device communications with the selected WTRUs for performing the collaborative service.

[0275] According to an embodiment of the method, the configuration information comprises policy and parameters for setting up the collaborative service.

[0276] According to an embodiment of the method, the first indication is received from one of an application or application server.

[0277] According to an embodiment of the method, the second indication comprises an identifier of the collaboration group.

[0278] According to an embodiment of the method, the identifier of the collaboration group is assigned by one of

[0279] an application or an application server;

[0280] the WTRU.

[0281] According to an embodiment of the method, the second indication is a radio resource control, RRC, update request.

[0282] According to an embodiment of the method, the second indication comprises information identifying the WTRU to the network node serving the WTRU as a target WTRU for the collaboration group.

[0283] There is also disclosed a wireless transmit-receive unit, WTRU, comprising at least one processor, the at least one processor configured to, according to embodiments:

[0284] receive configuration information for setting up a collaborative service;

[0285] receive a first indication to initiate a collaboration group of WTRUs for realizing the collaborative service, based on the received configuration information;

[0286] send discovery requests to other WTRUs for assistance of the WTRU in the collaboration group to realize the collaborative service for the WTRU;

[0287] receive responses to the discovery requests from at least one of the other WTRUs, indicating support for assistance of the WTRU in the collaboration group;

[0288] send a second indication of the initiation of the collaboration group to a network node serving the WTRU, the second indication comprising information relative to WTRUs selected from the at least one of the other WTRUs that indicated support for assistance of the WTRU in the collaboration group; and

[0289] set up device-to-device communications with the selected WTRUs for performing the collaborative service.

[0290] According to an embodiment of the WTRU, the configuration information comprises policy and parameters for setting up the collaborative service.

[0291] According to an embodiment of the WTRU,

[0292] 10. The WTRU of claim 8 or 9, wherein the at least one processor is configured to receive the first indication from one of an application or application server.

[0293] According to an embodiment of the WTRU, the second indication comprises an identifier of the collaboration group.

[0294] According to an embodiment of the WTRU, the identifier of the collaboration group is assigned by one of

[0295] an application or an application server;

[0296] the WTRU.

[0297] According to an embodiment of the WTRU, the second indication is a remote resource control, RRC, update request.

[0298] According to an embodiment of the WTRU, the second indication comprises information identifying the WTRU to the network node serving the WTRU as a target WTRU for the collaboration group.

[0299] Figure 10 is a method, implemented by a wireless transmit-receive unit, WTRU according to an embodiment. The method comprising:

[0300] receiving (1000) configuration information for performing a collaborative service;

[0301] creating (1001) a collaboration group based on the received configuration information, the collaboration group comprising the WTRU and at least another WTRU;

[0302] receiving (1002) a message comprising an indication for path switching of at least some of traffic of the WTRU through an indirect path via a WTRU-to-network relay;

[0303] establishing (1003) a connection with the WTRU-to-network relay, the WTRU-to- network relay establishing, for the WTRU, a connection with a network node serving the WTRU- to-network relay; and

[0304] sending / receiving (1004) the at least some traffic via the connection established with the WTRU-to-network relay.

[0305] According to an embodiment of the method, under condition that the network node serving the WTRU-to-network relay is different from a network node serving the WTRU, the WTRU-to-network relay is handed over to the network node serving the WTRU.

[0306] According to an embodiment of the method, the connection with the network node serving the WTRU-to-network relay, established for the WTRU by the WTRU-to-network relay, is established via radio resource control, RRC, messages.

[0307] According to an embodiment of the method, the collaborative service is a layer 2 or layer 3 based collaborative service.

[0308] According to an embodiment of the method, under condition that the collaborative service is a layer 3 based collaborative service, the method comprises a protocol data unit session setup via the WTRU-to-network relay.

[0309] There is also disclosed an described a wireless transmit-receive unit, WTRU, comprising at least one processor, the at least one processor being configured to, according to an embodiment:

[0310] receive configuration information for performing a collaborative service;

[0311] create a collaboration group based on the received configuration information, the collaboration group comprising the WTRU and at least another WTRU;

[0312] receive a message comprising an indication for path switching of at least some of traffic of the WTRU through an indirect path via a WTRU-to-network relay;

[0313] establish a connection with the WTRU-to-network relay, the WTRU-to-network relay establishing, for the WTRU, a connection with a network node serving the WTRU-to-network relay; and

[0314] send / receive the at least some traffic via the connection established with the WTRU-to- network relay.

[0315] According to an embodiment of the WTRU, under condition that the network node serving the WTRU-to-network relay is different from a network node serving the WTRU, the WTRU-to-network relay is handed over to the network node serving the WTRU.

[0316] According to an embodiment of the WTRU, the at least one processor is configured to establish the connection with the network node serving the WTRU-to-network relay, established for the WTRU by the WTRU-to-network relay, via radio resource control, RRC, messages.

[0317] According to an embodiment of the WTRU, the collaborative service is a layer 2 based or a layer 3 based collaborative service.

[0318] According to an embodiment of the WTRU, the at least one processor is configured to, under condition that the collaborative service is a layer 3 based collaborative service, perform a protocol data unit session setup via the WTRU-to-network relay.

[0319] Figure 11 is a flow chart of a method for path switching for collaborative services according to an embodiment.

[0320] The method comprises:

[0321] receiving (1100) a trigger for path switching for at least some traffic between a group of WTRUs and a network node, the group of WTRUs comprising the WTRU and other WTRUs configured for communicating with the network node;

[0322] sending (1101), to the other WTRUs, a message comprising an indication of path switching for the at least some traffic;

[0323] determining (1102) at least a first candidate WTRU-to-network relay available for handling the at least some traffic;

[0324] receiving (1103), from one or more of the other WTRUs, in reply to the message, an indication of at least a second candidate WTRU-to-network relay available for handling the at least some traffic;

[0325] selecting (1104), from the at least a first candidate WTRU-to-network relay and the at least a second candidate WTRU-to-network relay, a WTRU-to-network relay for relaying the at least some traffic between the group of WTRUs and the network node;

[0326] sending (1105), to the selected WTRU-to-network relay, a request for path switching for the at least some traffic between the group of WTRUs and the network node; and

[0327] sending (1106), to the other WTRUs, information comprising an indication to the other WTRUs of the path switching for the at least some traffic between the group of WTRUs and the network node via the selected WTRU-to-network relay.

[0328] According to a further embodiment of the method, the request for path switching is a connection setup request comprising an indication of group mobility, and receiving a response message to the request, the response message indicating an identifier of a resource reserved by the selected WTRU-to-network relay for the group of WTRUs, and wherein the information comprising an indication to the other WTRUs of the path switching comprises the identifier of the resource.

[0329] According to a further embodiment of the method, the selected WTRU-to-network relay is common between the at least a first and the at least a second candidate WTRU-to-network relays.

[0330] According to a further embodiment of the method, the trigger is received from one of:

[0331] an application or an application server; and

[0332] a WTRU-to-network relay handling the at least some traffic between the group of WTRUs and the network node.

[0333] According to a further embodiment of the method, the trigger received from the application or the application server is caused by at least one member of the group of WTRUs experiencing a quality of service drop.

[0334] According to a further embodiment of the method, the trigger is received from the WTRU-to-network relay handling the at least some traffic between the group of WTRUs and the network node, due to the WTRU-to-network relay handling the at least some traffic between the group of WTRUs and the network node having insufficient resources to handle the at least some traffic.

[0335] According to a further embodiment of the method, the group of WTRUs is formed for a collaborative service, the at least a first and at least a second candidate WTRU-to-network relays support the collaborative service.

[0336] There is also disclosed and described a wireless transmit-receive unit, WTRU, comprising at least one processor, the at least one processor according to an embodiment being configured to:

[0337] receive a trigger for path switching for at least some traffic between a group of WTRUs and a network node, the group of WTRUs comprising the WTRU and other WTRUs configured for communicating with the network node;

[0338] send, to the other WTRUs, a message comprising an indication of path switching for the at least some traffic;

[0339] determine at least a first candidate WTRU-to-network relay available for handling the at least some traffic;

[0340] receive, from one or more of the other WTRUs, in reply to the message, an indication of at least a second candidate WTRU-to-network relay available for handling the at least some traffic;

[0341] select, from the at least a first candidate WTRU-to-network relay and the at least a second candidate WTRU-to-network relay, a WTRU-to-network relay for relaying the at least some traffic between the group of WTRUs and the network node;

[0342] send, to the selected WTRU-to-network relay, a request for path switching for the at least some traffic between the group of WTRUs and the network node; and

[0343] send, to the other WTRUs, information comprising an indication to the other WTRUs of the path switching for the at least some traffic between the group of WTRUs and the network node via the selected WTRU-to-network relay.

[0344] According to an embodiment, the request for path switching is a connection setup request comprising an indication of group mobility, and receiving a response message to the request, the response message indicating an identifier of a resource reserved by the selected WTRU-to-network relay for the group of WTRUs, and wherein the information comprising an indication to the other WTRUs of the path switching comprises the identifier of the resource.

[0345] According to an embodiment, the selected WTRU-to-network relay is common between the at least a first and the at least a second candidate WTRU-to-network relays.

[0346] According to an embodiment, the trigger is received from one of:

[0347] an application or an application server; and

[0348] a WTRU-to-network relay handling the at least some traffic between the group of WTRUs and the network node.

[0349] According to an embodiment, the trigger received from the application or the application server is caused by at least one member of the group of WTRUs experiencing a quality of service drop.

[0350] According to an embodiment, the trigger is received from the WTRU-to-network relay handling the at least some traffic between the group of WTRUs and the network node, due to the WTRU-to-network relay handling the at least some traffic between the group of WTRUs and the network node having insufficient resources to handle the at least some traffic.

[0351] According to an embodiment, the group of WTRUs is formed for a collaborative service, the at least a first and the at least a second candidate WTRU-to-network relays support the collaborative service.

[0352] Conclusion

[0353] Although features and elements are provided above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations may be made without departing from its spirit and scope, as will be apparent to those skilled in the art. No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly provided as such. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will beapparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods or systems.

[0354] The foregoing embodiments are discussed, for simplicity, with regard to the terminology and structure of wireless communication capable devices, (e.g., radio wave emitters and receivers). However, the embodiments discussed are not limited to these systems but may be applied to other systems that use other forms of electromagnetic waves or non-electromagnetic waves such as acoustic waves.

[0355] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used herein, the term "video" or the term "imagery" may mean any of a snapshot, single image and / or multiple images displayed over a time basis. As another example, when referred to herein, the terms "user equipment" and its abbreviation "UE", the term "remote" and / or the terms "head mounted display" or its abbreviation "HMD" may mean or include (i) a wireless transmit and / or receive unit (WTRU); (ii) any of a number of embodiments of a WTRU; (iii) a wireless-capable and / or wired-capable (e.g., tetherable) device configured with, inter alia, some or all structures and functionality of a WTRU; (iii) a wireless-capable and / or wired-capable device configured with less than all structures and functionality of a WTRU; or (iv) the like. Details of an example WTRU, which may be representative of any WTRU recited herein, are provided herein with respect to FIGs. 1 A-1D. As another example, various disclosed embodiments herein supra and infra are described as utilizing a head mounted display. Those skilled in the art will recognize that a device other than the head mounted display may be utilized and some or all of the disclosure and various disclosed embodiments can be modified accordingly without undue experimentation. Examples of such other device may include a drone or other device configured to stream information for providing the adapted reality experience.

[0356] In addition, the methods provided 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 over wired or wireless connections) and computer-readable storage media. Examples of computer- readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, 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 disks (DVDs). A processor in association withsoftware may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

[0357] Variations of the method, apparatus and system provided above are possible without departing from the scope of the invention. In view of the wide variety of embodiments that can be applied, it should be understood that the illustrated embodiments are examples only, and should not be taken as limiting the scope of the following claims. For instance, the embodiments provided herein include handheld devices, which may include or be utilized with any appropriate voltage source, such as a battery and the like, providing any appropriate voltage.

[0358] Moreover, in the embodiments provided above, processing platforms, computing systems, controllers, and other devices that include processors are noted. These devices may include at least one Central Processing Unit ("CPU") and memory. In accordance with the practices of persons skilled in the art of computer programming, reference to acts and symbolic representations of operations or instructions may be performed by the various CPUs and memories. Such acts and operations or instructions may be referred to as being "executed," "computer executed" or "CPU executed."

[0359] One of ordinary skill in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. An electrical system represents data bits that can cause a resulting transformation or reduction of the electrical signals and the maintenance of data bits at memory locations in a memory system to thereby reconfigure or otherwise alter the CPU's operation, as well as other processing of signals. The memory locations where data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties corresponding to or representative of the data bits. It should be understood that the embodiments are not limited to the above-mentioned platforms or CPUs and that other platforms and CPUs may support the provided methods.

[0360] The data bits may also be maintained on a computer readable medium including magnetic disks, optical disks, and any other volatile (e.g., Random Access Memory (RAM)) or non-volatile (e.g., Read-Only Memory (ROM)) mass storage system readable by the CPU. The computer readable medium may include cooperating or interconnected computer readable medium, which exist exclusively on the processing system or are distributed among multiple interconnected processing systems that may be local or remote to the processing system. It should be understood that the embodiments are not limited to the above-mentioned memories and that other platforms and memories may support the provided methods.

[0361] In an illustrative embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readable medium. Thecomputer-readable instructions may be executed by a processor of a mobile unit, a network element, and / or any other computing device.

[0362] There is little distinction left between hardware and software implementations of aspects of systems. The use of hardware or software is generally (but not always, in that in certain contexts the choice between hardware and software may become significant) a design choice representing cost versus efficiency tradeoffs. There may be various vehicles by which processes and / or systems and / or other technologies described herein may be effected (e.g., hardware, software, and / or firmware), and the preferred vehicle may vary with the context in which the processes and / or systems and / or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a mainly hardware and / or firmware vehicle. If flexibility is paramount, the implementer may opt for a mainly software implementation. Alternatively, the implementer may opt for some combination of hardware, software, and / or firmware.

[0363] The foregoing detailed description has set forth various embodiments of the devices and / or processes via the use of block diagrams, flowcharts, and / or examples. Insofar as such block diagrams, flowcharts, and / or examples include one or more functions and / or operations, it will be understood by those within the art that each function and / or operation within such block diagrams, flowcharts, or examples may be implemented, individually and / or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In an embodiment, several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), and / or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, may be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and / or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein may be distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include, but are not limited to, the following: a recordable type medium such as a floppy disk, a hard disk drive, a CD, a DVD, a digital tape, a computer memory, etc., and a transmission type medium such as a digital and / or an analogcommunication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.).

[0364] Those skilled in the art will recognize that it is common within the art to describe devices and / or processes in the fashion set forth herein, and thereafter use engineering practices to integrate such described devices and / or processes into data processing systems. That is, at least a portion of the devices and / or processes described herein may be integrated into a data processing system via a reasonable amount of experimentation. Those having skill in the art will recognize that a typical data processing system may generally include one or more of a system unit housing, a video display device, a memory such as volatile and non-volatile memory, processors such as microprocessors and digital signal processors, computational entities such as operating systems, drivers, graphical user interfaces, and applications programs, one or more interaction devices, such as a touch pad or screen, and / or control systems including feedback loops and control motors (e.g., feedback for sensing position and / or velocity, control motors for moving and / or adjusting components and / or quantities). A typical data processing system may be implemented utilizing any suitable commercially available components, such as those typically found in data computing / communication and / or network computing / communication systems.

[0365] The herein described subject matter sometimes illustrates different components included within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures may be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality may be achieved. Hence, any two components herein combined to achieve a particular functionality may be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated may also be viewed as being "operably connected", or "operably coupled", to each other to achieve the desired functionality, and any two components capable of being so associated may also be viewed as being "operably couplable" to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and / or physically interacting components and / or wirelessly interactable and / or wirelessly interacting components and / or logically interacting and / or logically interactable components.

[0366] With respect to the use of substantially any plural and / or singular terms herein, those having skill in the art can translate from the plural to the singular and / or from the singular to the plural as is appropriate to the context and / or application. The various singular / plural permutations may be expressly set forth herein for sake of clarity.

[0367] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, where only one item is intended, the term "single" or similar language may be used. As an aid to understanding, the following appended claims and / or the descriptions herein may include usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim including such introduced claim recitation to embodiments including only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and / or "an" should be interpreted to mean "at least one" or "one or more"). The same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B." Further, the terms "any of' followed by a listing of a plurality of items and / or a plurality of categories of items, as used herein, are intended to include "any of," "any combination of," "any multiple of," and / or "any combinationof multiples of the items and / or the categories of items, individually or in conjunction with other items and / or other categories of items. Moreover, as used herein, the term "set" is intended to include any number of items, including zero. Additionally, as used herein, the term "number" is intended to include any number, including zero. And the term "multiple", as used herein, is intended to be synonymous with "a plurality".

[0368] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0369] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein may be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as "up to," "at least," "greater than," "less than," and the like includes the number recited and refers to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth.

[0370] Moreover, the claims should not be read as limited to the provided order or elements unless stated to that effect. In addition, use of the terms "means for" in any claim is intended to invoke 35 U.S.C. §112, 6 or means-plus-function claim format, and any claim without the terms "means for" is not so intended.

Claims

CLAIMSWhat is claimed is:

1. A method, implemented by a wireless transmit-receive unit, WTRU, the method comprising: receiving a trigger for path switching for at least some traffic between a group of WTRUs and a network node, the group of WTRUs comprising the WTRU and other WTRUs configured for communicating with the network node; sending, to the other WTRUs, a message comprising an indication of path switching for the at least some traffic; determining at least a first candidate WTRU-to-network relay available for handling the at least some traffic; receiving, from one or more of the other WTRUs, in reply to the message, an indication of at least a second candidate WTRU-to-network relay available for handling the at least some traffic; selecting, from the at least a first candidate WTRU-to-network relay and the at least a second candidate WTRU-to-network relay, a WTRU-to-network relay for relaying the at least some traffic between the group of WTRUs and the network node; sending, to the selected WTRU-to network relay, a request for path switching for the at least some traffic between the group of WTRUs and the network node; and sending, to the other WTRUs, information comprising an indication to the other WTRUs of the path switching for the at least some traffic between the group of WTRUs and the network node via the selected WTRU-to-network relay.

2. The method according to claim 1, wherein the request for path switching is a connection setup request comprising an indication of group mobility, and receiving a response message to the request, the response message indicating an identifier of a resource reserved by the selected WTRU-to-network relay for the group of WTRUs, and wherein the information comprising an indication to the other WTRUs of the path switching comprises the identifier of the resource.

3. The method of claim 1, wherein the selected WTRU-to-network relay is common between the at least a first and the at least a second candidate WTRU-to-network relays.

4. The method of claim 1, wherein the trigger is received from one of: an application or an application server; anda WTRU-to-network relay handling the at least some traffic between the group of WTRUs and the network node.

5. The method of claim 4, wherein the trigger received from the application or the application server is caused by at least one member of the group of WTRUs experiencing a quality of service drop.

6. The method of claim 4, wherein the trigger is received from the WTRU-to-network relay handling the at least some traffic between the group of WTRUs and the network node, due to the WTRU-to-network relay handling the at least some traffic between the group of WTRUs and the network node having insufficient resources to handle the at least some traffic.

7. The method of any of claims 1 to 6, wherein the group of WTRUs is formed for a collaborative service, the at least a first and at least a second candidate WTRU-to-network relays support the collaborative service.

8. A wireless transmit-receive unit, WTRU, comprising at least one processor, the at least one processor being configured to: receive a trigger for path switching for at least some traffic between a group of WTRUs and a network node, the group of WTRUs comprising the WTRU and other WTRUs configured for communicating with the network node; send, to the other WTRUs, a message comprising an indication of path switching for the at least some traffic; determine at least a first candidate WTRU-to-network relay available for handling the at least some traffic; receive, from one or more of the other WTRUs, in reply to the message, an indication of at least a second candidate WTRU-to-network relay available for handling the at least some traffic; select, from the at least a first candidate WTRU-to-network relay and the at least a second candidate WTRU-to-network relay, a WTRU-to-network relay for relaying the at least some traffic between the group of WTRUs and the network node;send, to the selected WTRU-to-network relay, a request for path switching for the at least some traffic between the group of WTRUs and the network node; and send, to the other WTRUs, information comprising an indication to the other WTRUs of the path switching for the at least some traffic between the group of WTRUs and the network node via the selected WTRU-to-network relay.

9. The WTRU of claim 8, wherein the request for path switching is a connection setup request comprising an indication of group mobility, and receiving a response message to the request, the response message indicating an identifier of a resource reserved by the selected WTRU-to-network relay for the group of WTRUs, and wherein the information comprising an indication to the other WTRUs of the path switching comprises the identifier of the resource.

10. The WTRU of claim 8, wherein the selected WTRU-to-network relay is common between the at least a first and the at least a second candidate WTRU-to-network relays.

11. The WTRU of claim 8, wherein the trigger is received from one of: an application or an application server; and a WTRU-to-network relay handling the at least some traffic between the group of WTRUs and the network node.

12. The WTRU of claim 11, wherein the trigger received from the application or the application server is caused by at least one member of the group of WTRUs experiencing a quality of service drop.

13. The WTRU of claim 11, wherein the trigger is received from the WTRU-to-network relay handling the at least some traffic between the group of WTRUs and the network node, due to the WTRU-to-network relay handling the at least some traffic between the group of WTRUs and the network node having insufficient resources to handle the at least some traffic.

14. The WTRU of any of claims 8 to 13, wherein the group of WTRUs is formed for a collaborative service, the at least a first and the at least a second candidate WTRU-to-network relays support the collaborative service.

Images