Method and apparatus for enabling n3GPP communication between remote WTRU and relay wtru

Abstract

A relay wireless transmit / receive unit (WTRU) transmits (1110) a message to a network entity indicating that a ProSe service is relayed over a non-3GPP (N3GPP) connection. The relay WTRU receives (1110), from the network entity, policy information for WTRU-to-network relaying over the N3GPP. The policy information includes a relay service code (RSC), N3GPP identity information, and a supported security mode of N3GPP access. The relay WTRU broadcasts (1130) discovery information over a PC5 connection and establishes (1140) a PC5 connection for ProSe direct communication with a remote WTRU associated with the RSC, the PC5 connection comprising a security association with the remote WTRU. The relay WTRU performs (1150) secure boot of N3GPP access over the PC5 connection with the remote WTRU, establishes (1160) an N3GPP connection for ProSe direct communication, and establishes (1170) a new PDU session or alters (1170) an existing PDU session to relay traffic of the remote WTRU to the network entity.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 393,479, filed on July 29, 2022, the contents of which are incorporated herein by reference. Background Art

[0003] A ProSe WTRU-to-Network Relay entity provides functionality for a remote WTRU to support connectivity to a network. If the remote WTRU is outside New Radio (NR) coverage and cannot communicate directly with the network, or is within NR coverage but prefers to communicate using a relay's PC5 interface, the remote WTRU may discover and select a ProSe WTRU-to-Network Relay. The remote WTRU may establish a PC5 unicast connection for ProSe direct communication with the ProSe WTRU-to-Network Relay and access the network via the ProSe WTRU-to-Network Relay. Summary of the invention

[0004] A method and apparatus for relaying ProSe services over a non-3GPP (N3GPP) connection is disclosed. A relay wireless transmit / receive unit (WTRU) may transmit a message to a network entity indicating support for relaying ProSe services over a non-3GPP (N3GPP) connection. The relay WTRU may receive policy information for WTRU-to-network relaying over N3GPP from the network entity. The policy information may include a relay service code (RSC), N3GPP identity information, and a supported security mode for N3GPP access technology. The relay WTRU may broadcast discovery information over a PC5 connection. The discovery information may include the RSC, the N3GPP identity information, and the supported security mode for N3GPP access technology. The relay WTRU may establish a PC5 connection for ProSe direct communication with a remote WTRU associated with the RSC, the PC5 connection including a security association with the remote WTRU. The relay WTRU may perform secure bootstrapping for N3GPP access over the PC5 connection with the remote WTRU. The secure bootstrapping may include exchanging messages with the remote WTRU to share N3GPP security credentials. The N3GPP security credentials may be based on the supported security mode of the N3GPP access technology. The relay WTRU may establish an N3GPP connection for ProSe direct communication. The relay WTRU may establish a new packet data unit (PDU) session or modify an existing PDU session to relay the service of the remote WTRU to the network entity. The network entity may be a 5G core network entity and may be one or more of an access and mobility management function (AMF), a session management function (SMF), a policy and control function (PCF), a ProSe server, a direct discovery name management function (DDNMF), or a unified data management (UDM). The policy information may include: ProSe application and service information, an indication of which N3GPP access technologies are supported, which N3GPP access technologies can be used simultaneously, and security credential information. The RSC may be associated with the ProSe application and service information. The relay WTRU may receive N3GPP quality of service (QoS) information. Available relay WTRU information may be transmitted to the remote WTRU by a policy and control function (PCF). The available relay WTRU information may include a list of available relay WTRUs. The list of available relay WTRUs may be based on location or time. The secure bootstrapping may be performed using assistance information received from a ProSe server. Establishing a new packet data unit (PDU) session or modifying an existing PDU session may be based on quality of service (QoS) information. The relay WTRU may transmit information to a session management function (SMF) indicating that the N3GPP connection for ProSe direct communication is established. The relay WTRU may receive information about an aggregate maximum bit rate (AMBR) for a PDU session.The relay WTRU may manage the N3GPP connection with the remote WTRU such that the bit rate of the PDU session does not exceed the AMBR. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] A more detailed understanding may be obtained from the following description given by way of example in conjunction with the accompanying drawings, in which like reference numerals indicate like elements, and in which:

[0006] Figure 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented;

[0007] Figure 1B is an example of an embodiment in which Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within an illustrated communication system;

[0008] Figure 1C is an example of an embodiment in which Figure 1A A system diagram of an example Radio Access Network (RAN) and an example Core Network (CN) used within the illustrated communication system;

[0009] Figure 1D is an example of an embodiment in which Figure 1A A system diagram of an additional example RAN and an additional example CN used within the illustrated communication system;

[0010] Figure 2 It is an example of a reference model for 5G / next generation networks;

[0011] Figure 3 is an example of an architectural model using Layer 2 UE to Network Relay;

[0012] Figure 4 is an example of an end-to-end control plane for a remote UE using a Layer 2 UE-to-network relay;

[0013] Figure 5 is an example of an architectural model using Layer 3 UE to Network Relay;

[0014] Figure 6 is an example of an end-to-end control plane for a remote UE using a Layer 3 UE-to-network relay;

[0015] Figure 7 is an example of a remote UE connected to a relay UE via N3GPP access;

[0016] Figure 8 An example of provisioning and connection establishment via 3GPP PC5 signaling is shown;

[0017] Fig. 9 An example method of discovery and connection establishment via N3GPP PC5 signaling is shown;

[0018] Fig.10 An example method of switching direct communications between 3GPP and N3GPP access is shown;

[0019] Fig.11 An example method of establishing a relay connection for N3GPP direct communication is shown; and

[0020] Fig.12 An example method of 3GPP PC5 assisted discovery and N3GPP link establishment is shown. DETAILED DESCRIPTION

[0021] Figure 1A 1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources (including wireless bandwidth). For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail unique word discrete Fourier transform spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, and filter bank multi-carrier (FBMC), etc.

[0022] like Figure 1AAs shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110 and other networks 112, but it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a station (STA)) may be configured to send and / or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), consumer electronic devices, and devices operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0023] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an evolved Node B (eNB), a Home Node B, a Home evolved Node B, a Next Generation Node B (such as a gNode B (gNB)), a New Radio (NR) Node B, a site controller, an access point (AP), a wireless router, and the like. Although the base stations 114a, 114b are each depicted as a single element, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0024] Base station 114a may be part of RAN 104, which may also include other base stations and / or network elements (not shown), such as base station controllers (BSC), radio network controllers (RNC), and relay nodes. Base station 114a and / or base station 114b may be configured to send and / or receive wireless signals on one or more carrier frequencies, which may be referred to as cells (not shown). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of a licensed spectrum and an unlicensed spectrum. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Therefore, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In an embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to send and / or receive signals in a desired spatial direction.

[0025] 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).

[0026] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA, among others. For example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology, such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), that may use Wideband CDMA (WCDMA) to establish the air interface 116. WCDMA may include communication protocols, such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​Uplink (UL) Packet Access (HSUPA).

[0027] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA) that may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-APro).

[0028] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology (such as NR radio access) that may establish the air interface 116 using NR.

[0029] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may together implement LTE radio access and NR radio access, for example using the dual connectivity (DC) principle. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0030] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), and GSM EDGE (GERAN).

[0031] Figure 1AThe base station 114b in may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in local areas such as commercial venues, homes, vehicles, campuses, industrial facilities, sky corridors (e.g., for use by drones), and roads. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology (such as IEEE 802.11) to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology (such as IEEE 802.15) to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or a femtocell. As Figure 1A As shown, the base station 114 b may have a direct connection to the Internet 110. Therefore, the base station 114 b may not need to access the Internet 110 via the CN 106.

[0032] The RAN 104 may be in communication with the CN 106, which may be any type of network configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not described in detail in the specification, the CN 106 may be configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. Figure 1A Although not shown in the figure, it will be appreciated that the RAN 104 and / or the CN 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may utilize NR radio technology, the CN 106 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0033] The CN 106 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT.

[0034] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0035] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0036] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of integrated circuit (IC), state machine, etc. The processor 118 may perform signal decoding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0037] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from a base station via an air interface 116. For example, in one embodiment, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In an embodiment, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, an IR, UV, or visible light signal. In another embodiment, the send / receive element 122 may be configured to send and / or receive both an RF signal and an optical signal. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0038] Although the transmit / receive element 122 Figure 1B Although depicted as a single element in the figure, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0039] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0040] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, and a secure digital (SD) memory card, among others. In other embodiments, the processor 118 may access information from and store data in a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0041] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel cadmium (NiCd), nickel zinc (NiZn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0042] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0043] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth Modules, frequency modulation (FM) radio units, digital music players, media players, video game player modules, Internet browsers, virtual reality and / or augmented reality (VR / AR) devices and activity trackers, etc. The peripheral device 138 may include one or more sensors. The sensor may be one or more of the following: a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geographic location sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and a humidity sensor, etc.

[0044] 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 specific subframes for both UL (e.g., for transmission) and DL (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference via signal processing performed by hardware (e.g., a choke) or via a processor (e.g., a separate processor (not shown) or via the processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with specific subframes for both UL (e.g., for transmission) or DL ​​(e.g., for reception)) may be concurrent and / or simultaneous.

[0045] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0046] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0047] Each of the evolved Node Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, and scheduling of users in the UL and / or DL, among other things. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0048] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. Although the foregoing elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0049] The MME 162 may be connected to each of the evolved Node-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, and selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0050] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during an inter-evolved Node-B handover, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0051] 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.

[0052] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers.

[0053] Although the WTRU Figures 1A to 1D Although described as wireless terminals, it is contemplated that in certain representative embodiments, such terminals may (eg, temporarily or permanently) use a wired communication interface with a communication network.

[0054] In a representative embodiment, the other network 112 may be a WLAN.

[0055] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for a BSS and one or more stations (STAs) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or carries traffic away from the BSS. Traffic originating from outside the BSS and going to the STA may arrive through the AP and may be delivered to the STA. Traffic originating from the STA and going to a target outside the BSS may be transmitted to the AP to be delivered to the corresponding target. Traffic between STAs within the BSS may be transmitted through the AP, for example, wherein the source STA may transmit traffic to the AP, and the AP may deliver traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic may be transmitted between the source STA and the target STA (e.g., directly between them) using a direct link establishment (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (eg, all STAs in the STA) may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0056] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP may send beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a dynamically set width. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0057] High throughput (HT) STAs may communicate using a 40 MHz wide channel (eg, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels) to form a 40 MHz wide channel.

[0058] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and the data can be sent by sending STA. At the receiver of the receiving STA, the above-mentioned operation for 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0059] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter type control / machine type communication (MTC), such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0060] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (which only supports a 1MHz operating mode) is transmitting to the AP, all available bands may be considered busy even if most of the available bands remain idle.

[0061] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0062] Figure 1D1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0063] The RAN 104 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 104 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send wireless signals to and / or receive wireless signals from the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, gNB 180a may transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In an embodiment, gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0064] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with parameter sets that may be scalable. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or Transmission Time Intervals (TTIs) of varying or scalable lengths (e.g., containing different numbers of OFDM symbols and / or varying absolute time lengths over time).

[0065] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeB 160a, 160b, 160c may act as a mobility anchor for the WTRUs 102a, 102b, 102c, and the gNB 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0066] Each of the gNBs 180a, 180b, 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, interworking between DC, NR and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b and routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0067] Figure 1DThe illustrated CN 106 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although the aforementioned elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0068] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of non-access stratum (NAS) signaling, and mobility management, etc. The AMF 182a, 182b may use network slicing to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, and services for MTC access. The AMF 182a, 182b may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0069] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 106 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 106 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy implementation and QoS, and providing DL data notifications. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0070] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering DL packets, and providing mobility anchoring, etc.

[0071] The CN 106 may facilitate communications with other networks. For example, the CN 106 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to the DNs 185a, 185b via the UPFs 184a, 184b via the N3 interfaces to the UPFs 184a, 184b and the N6 interfaces between the UPFs 184a, 184b and the local DNs 185a, 185b.

[0072] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with reference to one or more of the following may be performed by one or more simulation devices (not shown): WTRU102a to 102d, base station 114a to 114b, evolved Node B 160a to 160c, MME 162, SGW 164, PGW 166, gNB180a to 180c, AMF 182a to 182b, UPF 184a to 184b, SMF 183a to 183b, DN 185a to 185b and / or any other device described herein. The simulation device may be one or more devices configured to mimic one or more or all of the functions described herein. For example, the simulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0073] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. A simulation device may be directly coupled to another device for the purpose of testing and / or performing tests using over-the-air wireless communications.

[0074] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via RF circuits (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0075] Figure 2 An example of a reference model of a potential architecture for a 5G or next generation network is shown. RAN in this document refers to a radio access network based on 5G RAT or Evolved E-UTRA, which is connected to a next generation core network. The access control and mobility management function (AMF) may include at least one of the following functionalities: registration management, connection management, reachability management, and mobility management. The session management function (SMF) may include at least the following functionalities: session management (including session establishment, modification, and release), WTRU IP address allocation, and selection and control of UP functions. The user plane function (UPF) may include at least the following functionalities: packet routing and forwarding, packet inspection, and service usage reporting.

[0076] Layer 2 WTRU to Network (NW) Relay may provide a Layer 2 remote WTRU with the ability to support Figure 3 and Figure 4 The AS layer forwarding shown implements the connectivity to the network functionality. Figure 3 In the WTRU-NW Relay, the remote WTRU has a PC5 connection to the WTRU-NW Relay. The WTRU-NW Relay has a Uu connection to the RAN. The core network includes AMF-Relay (i.e., the AMF of the WTRU to NW Relay), SMF-Relay (i.e., the SMF of the WTRU to NW Relay), AMF-Remote (i.e., the AMF of the remote WTRU), and SMF-Remote (i.e., the SMF of the remote WTRU). The core network has a connection to the data network.

[0077] exist Figure 4 In the example, the remote WTRU has a PC5 connection to the WTRU-NW relay. The WTRU-NW relay has a Uu connection to the RAN. The RAN has an N2 connection to the AMF-remote WTRU. The AMF-remote WTRU has an N11 connection to the SMF-remote WTRU. The control plane protocol stack is in Figure 4 , and is an example of an end-to-end control plane for a remote WTRU using a Layer 2 WTRU to NW relay.

[0078] If a session (such as a PC5 session) is established between a Layer 2 remote WTRU and a Layer 2 WTRU to NW relay, the Layer 2 WTRU to NW relay may forward RRC signaling and traffic between the Layer 2 remote WTRU and the RAN. If signaling is received via the Uu interface, the RAN may determine whether the received signaling is from the WTRU to NW relay itself or from a remote WTRU via the WTRU to NW relay. The RAN may perform the corresponding procedures using an AMF-relay (e.g., an AMF serving the WTRU to NW relay) or an AMF-remote WTRU (e.g., an AMF serving the remote WTRU). The AMF-relay and the AMF-remote WTRU may belong to different core networks. In order to provide AS layer forwarding, the Layer 2 WTRU to NW relay must remain in connected mode if any Layer 2 remote WTRU is in connected mode.

[0079] Layer 3 WTRU to NW relay provides a means for Layer 3 remote WTRUs to support Figure 5 and Figure 6 The IP layer forwarding shown implements the functionality of connectivity to the network.

[0080] After the PC5 session is established between the Layer 3 remote WTRU and the Layer 3 WTRU-to-NW relay, the Layer 3 WTRU-to-NW relay establishes a new PDU session or modifies an existing PDU session to provide connectivity between the Layer 3 remote WTRU and the core network. For example, if an IP type PDU session is established for the Layer 3 remote WTRU, the Layer 3 WTRU-to-NW relay assigns an IP address / prefix to the Layer 3 remote WTRU. The Layer 3 remote WTRU then uses the IP connection to access the Internet or to access back to the core network of the Layer 3 remote WTRU.

[0081] The current relay scenario can be extended to support devices connected via non-3GPP (N3GPP) access, such as Bluetooth (BT) or WiFi. Figure 7 Some of these scenarios are shown. Figure 7As shown in , a remote WTRU is connected to a relay WTRU via N3GPP access (eg, WiFi or BT) (eg, a L3 WTRU to NW relay scenario). Figure 7 The small dashed line in shows the data from the N3GPP connection, while Figure 7 The large dashed line in the figure shows data from 3GPP devices. XR services (e.g., smart glasses connected to the network via a smartphone acting as a relay WTRU) is one of the use cases for this scenario. XR services may have strict performance requirements on throughput, latency, and reliability. Another possible use case is an automotive scenario (e.g., a smartphone connected to the network via a vehicle acting as a relay WTRU).

[0082] like Figure 7 As shown in , the transmission path between the remote WTRU and the relay WTRU is an N3GPP connection (e.g., WiFi or BT). The path between the relay WTRU and the network is via a 3GPP path. The WTRU to NW relay should be able to provide support to meet the performance requirements based on N3GPP, especially when supporting use cases that require high QoS (e.g., XR scenarios or automotive scenarios). These scenarios have strict performance requirements in terms of latency, throughput, and reliability.

[0083] The remote WTRU needs to discover a relay WTRU that supports N3GPP communications and establish an N3GPP connection with the relay WTRU. The procedures for such communications need to be defined between the remote WTRU and the relay WTRU. The relay WTRU may need to interact with the network to facilitate such an N3GPP connection between the remote WTRU and the relay WTRU. Such interactions also need to be defined.

[0084] Because an adversary can impersonate a relay that provides N3GPP access to a ProSe relay. Therefore, the remote WTRU needs to ensure that the relay is authorized to provide ProSe relay services using an N3GPP connection and vice versa. In order to avoid eavesdropping or tampering with communications conducted over the N3GPP connection, the remote WTRU and the relay also need to be able to establish a secure N3GPP connection for ProSe relay services. For example, when exchanging data over an N3GPP connection, the remote WTRU and the relay need to ensure at least the same level of protection to avoid security degradation when the communication between the remote WTRU and the relay switches between 3GPP and N3GPP connections.

[0085] Based on various conditions or triggers, the N3GPP connection between the remote WTRU and the relay WTRU may need to be switched to a 3GPP PC5 connection, or vice versa. For example, different billing may be applied to the N3GPP connection compared to the PC5 connection, or the required QoS may not be supported by PC5, which may make it more advantageous to use the N3GPP connection. If the expected service data rate is not high, it may be beneficial to select Bluetooth (BT) or Bluetooth Low Energy (BLE) for the relay service to achieve efficient battery consumption for the remote WTRU. For high demand services, WiFi or WiFi Direct technology may be better than PC5 to transfer data to the remote WTRU via the relay WTRU.

[0086] The process of switching between N3GPP and 3GPP connections may involve the remote WTRU, the relay, and the network. Service requirements for communications between the remote WTRU and the relay WTRU need to be ensured. The embodiments described herein take this requirement into account.

[0087] The embodiments described herein assume that the WTRU supports PC5 signaling. PC5 signaling may be supported by the ProSe layer in the WTRU. The ProSe layer may interact with the N3GPP stack in the WTRU. The ProSe layer may be implemented on top of the N3GPP stack. This applies to both 3GPP WTRUs and N3GPP WTRUs. The WTRU in the embodiments described herein may be, for example, a ProSe WTRU, a WTRU that is part of a personal IoT network (PIN), or a ProSe WTRU that supports ranging / SL positioning functionality. In the case of a PIN, the WTRU may be a PIN element, a PIN element with gateway capabilities (PEGC), or a PIN element with management capabilities (PEMC).

[0088] A relay WTRU may interact with a network function (NF), which indicates that it supports N3GPP for a given application. In addition to standard ProSe or PIN capabilities, the relay WTRU may also register its ability to support N3GPP access at the 5GC. The relay WTRU may receive a discovery code (which may indicate that an N3GPP direct connection is possible (e.g., an appendix in the discovery)), the type of direct connection supported (e.g., BT or WiFi), and N3GPP QoS information. The relay WTRU may broadcast a ProSe discovery code for N3GPP access over a PC5 link. The relay WTRU may broadcast a ProSe discovery code over N3GPP access. The relay WTRU may receive a discovery request message (e.g., with QoS information) or a direct link connection establishment request (e.g., with an indication that the direct connection is for N3GPP). The 3GPP radio bearer may be in a suspended state or a long DRX state. The relay WTRU may establish a PDU session with the network using authorization from the 5GCN (e.g., an indication in the PDU session that the connection is for N3GPP communication). The relay WTRU may exchange ProSe keep alive messages with the remote WTRU indicating that N3GPP communications are still occurring. The relay WTRU and the remote WTRU may perform procedures for bootstrapping N3GPP access security over a PC5 unicast link to exchange security credentials.

[0089] Discovering ProSe over N3GPP and establishing an N3GPP connection for ProSe direct communication may include providing the WTRU with the necessary information to find a peer WTRU with N3GPP access and establishing a connection to the peer WTRU. In an embodiment, a new network entity may be used, which may be responsible for providing information for discovering ProSe over N3GPP. The new network entity (e.g., a network function (NF)) may be a logical entity. The new network entity may be implemented by other existing network functions or servers (e.g., PCF, DDNMF or ProSe server, AMF, SMF). In an embodiment, the existing PC5 discovery process may be reused with the onboard information for discovering ProSe over N3GPP.

[0090] Figure 8 A method of provisioning and connection establishment via 3GPP PC5 signaling using a new logical network entity is shown. Registration 810, 820 may be performed between a WTRU and a network function (NF). WTRU1 and WTRU2 may transmit their capabilities for N3GPP access to the 5G core network 5GCN (e.g., AMF) at initial registration.

[0091] Provisioning of policy information and parameters for N3GPP-based ProSe 830, 840 may be performed. When WTRU1 and WTRU2 are authorized to use N3GPP-based ProSe services, WTRU1 and WTRU2 may receive policy and parameter information for N3GPP-based ProSe. WTRU1 and WTRU2 may receive the policy and parameter information from, for example, a policy and control function (PCF) or a direct discovery name management function (DDNMF). The WTRU may use N3GPP-based ProSe to discover peer WTRUs or relays based on the policy and parameter information provided from the 5GCN. The information may be provided during the registration process or in a separate process (e.g., WTRU configuration process) after registration. The policy and parameter information may include, for example, supported N3GPP connection types, such as WiFi or BT, supported ProSe application information, and an identity (ID) for N3GPP access, such as a BT ID, SSID, and / or MAC address. The policy and parameter information may also include the supported security modes of N3GPP and the security credential information to be used to establish the connection or the parameters used to derive the security credential information. The policy and parameter information may also include whether the ProSe relay service based on N3GPP access is supported. Depending on the application (e.g., ProSe App ID) that the WTRU is authorized to use, the available N3GPP connections may be different. The network entity may limit the information to the relevant WTRU based on geographical conditions (such as the WTRU location and the service area allowed for the ProSe application or the ProSe applications allowed by the requesting WTRU).

[0092] An N3GPP-based connection establishment procedure 850 may be performed. Using the provided policy and parameter information, WTRU1 may discover a peer WTRU or relay WTRU (e.g., WTRU2) that supports the desired N3GPP-based ProSe application and attempt an N3GPP-based connection establishment procedure with the discovered WTRU. If WTRU1 wants to discover a relay WTRU via N3GPP, WTRU1 may discover a peer WTRU that supports relay via N3GPP using the policy and parameter information provided from the 5GCN. Additionally, a discovery message may be broadcast (e.g., a notification message broadcast by WTRU2 (Model A) or a request message broadcast by WTRU1 (Model B)), and the discovery message may include an indication that discovery is being performed for N3GPP communications between WTRU1 and WTRU2. This may be included as part of the discovery code broadcast by the WTRU. When a security procedure is required for the N3GPP-based connection establishment, WTRU1 and WTRU2 may perform the security procedure using the security mode indicated in the policy and parameter information for N3GPP-based ProSe. The WTRU may utilize the input values ​​included in the policy and parameter information for N3GPP-based ProSe to derive any security credentials for the N3GPP-based security procedures.

[0093] WTRU1 or WTRU2 may transmit a ProSe direct communication request (REQ) (i.e., 3GPP PC5 signaling message) 860 to WTRU2 or WTRU1, respectively, over the established N3GPP connection. The direct communication request may include a source Layer 2 ID, a target Layer 2 ID for the requested unicast connection, ProSe service information, and expected application information. Some information such as the ProSe service information and the expected application information may be shared later after the ProSe unicast connection is established.

[0094] WTRU1 or WTRU2 may respond 870 with a ProSe direct communication accept message, respectively. The direct communication accept message may include QoS information for the established unicast connection (e.g., information about PC5 QoS flows, such as PFI, PQI, and other QoS parameters). Since the WTRU is aware that a ProSe connection is being established for N3GPP direct communication, the ProSe layer on both WTRUs may store this information. Since the ProSe connection is established over N3GPP access, a PC5 radio bearer may not be established. Alternatively, the WTRUs may establish a PC5 radio bearer but indicate to each other that the bearer is established in a suspended state or in a DRX state (DRX values ​​may be exchanged between the WTRUs). The QoS information may be passed to the N3GPP layer in the WTRU. The source L2 ID and the target L2 ID may be stored by the WTRU as they may be used when the connection is switched from N3GPP communication to 3GPP PC5 user communication.

[0095] WTRU1 and WTRU2 may exchange traffic 880 over the established N3GPP connection. The WTRUs may exchange ProSe signaling (eg, keep-alive messages) using N3GPP indications. WTRU1 and WTRU2 described in this embodiment may be a remote WTRU and a relay WTRU, respectively.

[0096] In an embodiment, during the PC5 discovery process, information for N3GPP network connections may be exchanged. This information may include direct connection type (e.g., BT or WiFi and identifier information for N3GPP services, such as MAC address, BT ID or WiFi SSID). Fig. 9 An example method of discovery and connection establishment via N3GPP PC5 signaling is shown.

[0097] It may be assumed that WTRU1 and WTRU2 are provisioned with an authorized N3GPP list for ProSe services and information such as a discovery code that may indicate that a N3GPP direct connection is possible.

[0098] The WTRU (WTRU1) may transmit a ProSe discovery request (REQ) message using a discovery code to discover a peer WTRU (WTRU2) 910 that supports a desired ProSe application based on N3GPP access. The ProSe discovery request message may be transmitted over a PC5 connection. The ProSe discovery request message may include N3GPP information, such as an indication of support for ProSe based on N3GGP, supported N3GPP connection types (e.g., WiFi or BT), supported ProSe application information based on ProSe (which is based on N3GPP), and an ID for N3GPP access, such as a BT ID, SSID, and / or MAC address. The N3GPP information may also include support for ProSe relay service. The N3GPP information may also be a pointer (e.g., a discovery code) to N3GPP provisioning information for a specific ProSe application received by the WTRU during the network provisioning process.

[0099] When the peer WTRU (WTRU2) receives the ProSe discovery request, the peer WTRU (WTRU2) may respond with a ProSe discovery accept or response (RSP) message 920. The ProSe discovery accept message may be transmitted over a PC5 connection. The ProSe discovery accept message may include connection information (such as N3GPP connection type) of N3GPP-based ProSe supported by the peer WTRU (WTRU2), ProSe application information based on ProSe support, and an ID for N3GPP access.

[0100] After receiving the ProSe Discovery Accept message, the WTRU (WTRU1) or the peer WTRU (WTRU2) may initiate N3GPP connection establishment 930 over N3GPP access.

[0101] The WTRU (WTRU1) or the peer WTRU (WTRU2) may transmit a ProSe direct communication request message 940 to the peer WTRU (WTRU2) or WTRU (WTRU1), respectively, over the established N3GPP connection. The ProSe direct communication request message may include the source Layer 2 ID and the target Layer 2 ID for the requested direct (unicast) connection, ProSe service information, expected application information, and security information. The peer WTRU (WTRU2) or WTRU (WTRU1), respectively, may respond with a ProSe direct communication accept message 940. The ProSe direct communication accept message may include QoS information (e.g., information about PC5 QoS flows, such as PFI, PQI, and other QoS parameters) for the established unicast connection. The WTRU (WTRU1) and the peer WTRU (WTRU2) may exchange traffic 940 over the established ProSe unicast connection. WTRU1 and WTRU2 may be a remote WTRU and a relay WTRU, respectively.

[0102] When a ProSe connection over N3GPP is established based on environmental changes such as WTRU mobility (e.g., the WTRU moves out of the provisioned N3GPP area for a particular ProSe application), WTRU power state, or channel conditions, it may not be possible to maintain the connection over the current N3GPP access or another N3GPP access or a PC5 channel may provide a better connection. It may be desirable to change the N3GPP access while maintaining the ProSe connection.

[0103] Fig.10 An example method of switching direct communications between 3GPP and N3GPP access is shown.

[0104] When a PC5-based ProSe connection or an N3GPP-based ProSe connection involves WTRU1 and WTRU2, each WTRU may monitor the access link for the current ProSe connection and / or perform a keep-alive procedure (e.g., transmit a keep-alive message) 1010. The keep-alive message may include an N3GPP indication. Each WTRU may save the N3GPP-supported information of the other WTRU (e.g., the type of direct connection such as BT or WiFi, identifier information such as MAC address, BT ID or WiFi SSID for N3GPP services, and a discovery code for N3GPP-based ProSe (with supported ProSe applications)).

[0105] If WTRU2's N3GPP-capable information is not available in WTRU1, or if WTRU1 wants to check WTRU2's N3GPP-capable information again, WTRU1 may transmit a message, such as a Path Information Request message for N3GPP-capable information (Path Information REQ) 1020. WTRU1 may include WTRU1's N3GPP-capable information in the Path Information REQ message.

[0106] In response to WTRU2 receiving the PATH INFORMATION REQ message from WTRU1, WTRU2 may respond with a message, such as a PATH INFORMATION Response message (PATH INFORMATION RSP) with WTRU2's N3GPP-capable information 1030. If the received PATH INFORMATION REQ message includes WTRU1's N3GPP-capable information, WTRU2 may store it for future use.

[0107] When WTRU1 may be triggered to perform link modification 1040 for RAT (Radio Access Technology) change, it may determine possible N3GPP access with WTRU2 by comparing the saved N3GPP supported information of WTRU2 with its available N3GPP information. WTRU1 may be triggered by the application layer, or based on observed link quality or preferences configured by the user or network via policy provisioning (e.g., N3GPP is preferred over PC5).

[0108] WTRU1 may transmit a link modification request (REQ) message 1050 to WTRU2 for link modification from a current RAT to another RAT. WTRU1 may include a target candidate N3GPP access list in the link modification REQ message. The target candidate N3GPP access list may include other N3GPP PRATS or PC5 accesses. When transmitting the link modification REQ message, if WTRU1 does not have WTRU2's N3GPP-supported information, WTRU1 may include an indication of requesting WTRU2's N3GPP-supported information. WTRU1 may include WTRU1's N3GPP-supported information in the link modification REQ message.

[0109] WTRU2 may transmit a Link Modification Response (RSP) message 1060 with the target N3GPP access information to WTRU1. WTRU2 may include the N3GPP support information if WTRU2 was requested, for example, in the Link Modification REQ message.

[0110] Based on the target N3GPP access information received from WTRU2 and the information of WTRU2's supported N3GPP, WTRU1 may attempt to discover WTRU2 in the target N3GPP access 1070. After discovering WTRU2, WTRU1 may trigger connection establishment with WTRU2 through the target N3GPP access. If no link modification REQ / RSP messages have been exchanged before, WTRU1 may determine a target candidate N3GPP access list based on WTRU2's supported N3GPP information, and WTRU1 may select a RAT from the target candidate N3GPP access list as the target N3GPP access to discover WTRU2. The target candidate N3GPP access list may include PC5 access. If WTRU2 is not found in the selected RAT, WTRU1 may select another RAT from the target candidate N3GPP access list as the target N3GPP access. If the target N3GPP access information includes PC5 access, WTRU1 and WTRU2 may perform discovery and connection establishment procedures through PC5. Through the established connection, WTRU1 and WTRU2 may exchange direct communication request messages and direct communication response messages. WTRU1 and WTRU2 may update the QoS information of the ProSe connection accordingly.

[0111] Data traffic may be exchanged through the new ProSe connection, and the previous ProSe connection 1080 may be released.

[0112] In an embodiment, the WTRU may transmit a ProSe link modification message with an indication of switching from N3GPP access to 3GPP for communication over 3GPP or N3GPP access. The indication may be transmitted in, for example, a keep alive message, a link identifier update message, or a direct link security mode message. The use of a link identifier update message allows the identifier (e.g., L2 ID, security ID) of the WTRU to be changed when switching to another access, which may prevent tracking / tracing of the WTRU from one access to another. When switching to 3GPP access, the use of a direct link security mode message allows security to be established for the ProSe connection. When switching to 3GPP access, the direct link security mode process may also be triggered during any of the processes specified herein. When the receiving WTRU confirms (e.g., via an indication) the request to switch from N3GPP access to 3GPP access or vice versa, the WTRU may decide to switch the connection. The confirmation message may be transmitted via a response message such as a link modification, keep alive, link identifier update, or direct link security mode, depending on what the other WTRU transmitted. When the access is switched from N3GPP to 3GPP PC5 communication, the ProSe layer may pass QoS information and other communication parameters (e.g., L2 ID) to the AS layer of the WTRU. The AS layer may establish a PC5 radio bearer for 3GPP PC5 communication between the WTRUs. When the access is switched from 3GPP to N3GPP communication, the ProSe layer may transmit such an indication to the AS layer. The AS layer may then deactivate, suspend, or use long DRX for the 3GPP PC5 radio bearer between the WTRUs.

[0113] WTRU1 and WTRU2 may resume ProSe direct communication over the new access channel.

[0114] In an embodiment, the relay WTRU may communicate with the 5GCN to establish a PDU session for WTRU to NW relay over N3GPP. Fig.11 An example method of establishing a relay connection for N3GPP direct communication is shown.

[0115] For authorization and policy provisioning, the relay WTRU may transmit a message to a network entity / network function (NF) (e.g., AMF, SMF, PCF, ProSe server, DDNMF, or unified database management (UDM)) indicating that the relay WTRU supports relaying ProSe services over N3GPP connections, and the relay WTRU may receive authorization to act as a relay WTRU for ProSe services over N3GPP connections (1110). The relay WTRU may be provisioned (e.g., receive information) with policy information such as ProSe application and service information, a relay service code (RSC) associated with the ProSe application and service information, and other policy information for ProSe WTRU to NW relaying over N3GPP. The policy information may include information such as which N3GPP access technologies may be supported and which of them may be used simultaneously. The policy information may include identity information that can be used to identify entities in the N3GPP access technology (e.g., SSID for WIFI), supported security modes for each supported N3GPP access technology, and security credential information to be used to establish a connection with a remote WTRU via the N3GPP access technology or parameters for deriving the security credential information. The PCF or ProSe server may provide this information to the relay WTRU. This information may be transferred to the relay WTRU via the AMF and NG-RAN. The ProSe server may provide this information to the 5GCN, which may be processed by the PCF. The relay WTRU may receive this information via a user plane connection made through a PDU session.

[0116] The remote WTRU may transmit a message to a network entity / network function (NF) (e.g., AMF, SMF, PCF, ProSe server, DDNMF, UDM) indicating that the remote WTRU supports relaying of ProSe services over N3GPP connections, and the remote WTRU may receive authorization to act as a remote WTRU for ProSe services over N3GPP connections 1120. The remote WTRU may be provisioned (e.g., receive provisioning information) with policy information such as ProSe applications and services information that the remote WTRU is allowed to use, a relay service code (RSC) associated with the ProSe applications and services information, and other policy information for accessing the ProSe WTRU to NW relay over N3GPP. The policy information may include information such as which N3GPP access technologies may be supported and which of them may be used simultaneously with the ProSe WTRU to NW relay over N3GPP. The policy information may include identity information that can be used to identify the relay WTRU entity in the N3GPP access technology (e.g., SSID for WiFi), supported security modes for each supported N3GPP access technology, and security credential information to be used to establish a connection with the relay WTRU via the N3GPP access technology or parameters for deriving the security credential information. The PCF or ProSe server may provide this information to the remote WTRU. This information may be transferred to the remote WTRU via the AMF and NG-RAN. The ProSe server may provide this information to the 5GCN, which may be processed by the PCF. The relay WTRU and the remote WTRU may receive supported QoS information (e.g., latency or data rate) and other QoS for each ProSe application for the N3GPP connection. The QoS information may be received from the ProSe server via the PCF.

[0117] Based on location and / or time, the available relay WTRU information (e.g., list) and supported N3GPP access technologies for each relay WTRU may be different. Therefore, the PCF may provide different policy information to the remote WTRU or to the relay WTRU according to location and time and validity conditions including location and time.

[0118] For the ProSe discovery procedure, the relay WTRU may broadcast discovery information 1130 over a PC5 connection. The discovery information may include, for example, an RSC for the ProSe WTRU to NW relay, an indication of N3GPP access support, a list of supported N3GPP access technologies, and associated security modes. The relay WTRU's N3GPP access technology specific identification information may be included in the broadcast discovery information. The relay WTRU's N3GPP access technology specific identification information may be shared during the ProSe link establishment procedure over a PC5 connection.

[0119] A PC5 connection may be established for ProSe direct communication between a remote WTRU and a relay WTRU 1140. When the remote WTRU discovers an RSC that belongs to a list of RSCs allowed for the remote WTRU, the remote WTRU may initiate a PC5 connection establishment for ProSe direct communication with the relay WTRU that broadcasts the RSC. For example, the remote WTRU may transmit a request message (e.g., a ProSe Direct Communication Request (DCR) message) to the relay WTRU to establish a PC5 unicast connection for ProSe direct communication. The relay WTRU may transmit a response message (e.g., a ProSe Direct Communication Accept (DCA) message) to the remote WTRU. The relay WTRU and the remote WTRU may establish a security association to protect the established PC5 unicast connection. The relay WTRU may establish a new PDU session for the relay service of the remote WTRU, or may reuse an existing PDU session for the relay service of the remote WTRU. The PDU session may be used to relay traffic from a remote WTRU transmitted over a PC5 unicast connection to the network over the PDU session, and may be used to receive traffic from the network over a PDU session for relaying traffic to the remote WTRU over a PC5 unicast connection.

[0120] A secure bootstrapping for N3GPP access may be performed 1150. A secure bootstrapping may be performed to prepare security credentials for establishing a security association between the remote WTRU and the relay WTRU over N3GPP. The remote WTRU and the relay WTRU may perform a secure bootstrapping for N3GPP access over a PC5 unicast connection.

[0121] For the secure boot process, the remote WTRU and the relay WTRU may exchange signaling or messages over a PC5 unicast connection to share security credentials for secure mode operation of the N3GPP access technology. This may be done during PC5 connection establishment for the ProSe direct communication process (e.g., using a Direct Communication Request (DCR) message, a Direct Security Mode (DSM) Command message, a DSM Complete message, or a Direct Communication Accept (DCA) message) or after the PC5 connection establishment process (e.g., using a Link Modification message or a Direct Link Key Update message). For example, the relay WTRU and the remote WTRU may share a symmetric key for accessing the remote WTRU over WiFi technology using the WEP security protocol.

[0122] Based on the security mode operation of the N3GPP access technology, the remote WTRU and the relay WTRU may perform different signaling or message exchanges for the required security protocols to exchange different security parameters and share security credentials. The remote WTRU may use security credentials provided by the network (e.g., PCF, ProSe server, DDNMF) or derived using parameters provided by the PCF / ProSe server to access the relay WTRU through the N3GPP access technology. The remote WTRU and the relay WTRU may exchange security credentials that may be dedicated to security credential management with the assistance of the ProSe server. For example, the ProSe server may identify the remote WTRU and the relay WTRU, check the validity and authenticity of each WTRU, and provide each WTRU with security credentials or security parameters for deriving security credentials.

[0123] When security credentials are shared between a remote WTRU and a relay WTRU, the relay WTRU and / or 5GCN may use the security credentials of the remote WTRU at the 3GPP system to check the validity of the remote WTRU and derive security credentials for accessing the relay WTRU via N3GPP access.

[0124] After successfully sharing the security credentials between the remote WTRU and the relay WTRU, the remote WTRU can communicate with the relay WTRU through N3GPP access using the shared security credentials, and can initiate the ProSe link establishment process or switch the established PC5 connection for ProSe communication to N3GPP access 1160 through N3GPP access (i.e., N3GPP connection establishment for ProSe direct communication) (e.g., using DCR, DSM command, DSM completion, or DCA message).

[0125] For PDU session management for PC5 and N3GPP based access in, for example, L3 WTRU to NW relay, the relay WTRU may establish a PDU session 1170 for relaying services of the remote WTRU. During or after unicast link establishment (e.g., ProSe link establishment procedure), the remote WTRU may transmit information such as the requested DNN, IP type, SSC mode, QoS information for the expected relay service from the relay WTRU to the relay WTRU. Considering the QoS requirements and the requested parameters from the remote WTRU, the relay WTRU may establish a PDU session for relaying services over N3GPP access, or the relay WTRU may reuse or modify an existing PDU session to relay services over N3GPP access regardless of the access technology. Based on the QoS information for the N3GPP based ProSe service, the relay WTRU may modify the existing PDU session or establish a new PDU session with the remote WTRU for N3GPP based WTRU to NW relay. During the PDU session establishment or modification process, the relay WTRU may transmit information about establishing a ProSe connection through an N3GPP connection and QoS information based on the N3GPP connection to the SMF. The SMF may update the QoS characteristics of the PDU session based on the reported characteristics of the N3GPP connection and the supported QoS information.

[0126] The relay WTRU may transmit information to the remote WTRU regarding whether a new PDU Session is to be assigned or an existing PDU Session is to be reused or modified. The remote WTRU may receive information from the relay WTRU regarding supported QoS characteristics for N3GPP links or PC5 links. The relay WTRU may transmit information to the remote WTRU regarding maximum bit rate limits for relay access to PC5, N3GPP links, or all links.

[0127] When a dedicated PDU session for relay service over N3GPP access is established, the relay WTRU may be assigned or receive information about parameters of an aggregate maximum bit rate (AMBR) based on the PDU session (e.g., session AMBR) during the PDU session establishment. The relay WTRU may manage the N3GPP access with the remote WTRU so that the bit rate of the PDU session for the relay service does not exceed the session AMBR. The AMBR for the PDU session (i.e., session AMBR) is among the PDU session related parameters that may be transmitted by the SMF. The PDU session related parameters may be included in a PDU session establishment response message or a PDU session modification response message transmitted by the SMF and received by the relay WTRU. The relay WTRU may transmit information to the remote WTRU that the maximum bit rate limit for the N3GPP access to the remote WTRU is less than or equal to the session AMBR.

[0128] When an existing PDU session for relay service is to be used for relay service over N3GPP access, the relay WTRU may manage and ensure that the sum of the data rate over the PC5 link and the data rate over the N3GPP link does not exceed the session AMBR. The relay WTRU may transmit information about the maximum bit rate limit of the PC5 and the maximum bit rate limit of the N3GPP separately to the remote WTRU, or the relay WTRU may transmit information about the maximum bit rate limit of the PC5 and NG3GPP access combined. The sum of the maximum bit rate limits cannot exceed the session AMBR.

[0129] Transmission over PC5 and N3GPP access for relay services may be performed simultaneously. The remote WTRU and the relay WTRU may manage PC5 unicast connections and N3GPP unicast connections together. Based on QoS requirements and policies, each unicast connection may be mapped to a different PDU session of the relay WTRU, or each unicast connection may be mapped to a PDU session of the relay WTRU. When the PDU session of the relay WTRU is used for PC5 unicast connections and N3GPP unicast connections, the remote WTRU may decide to assign each data flow to a unicast connection or to use multiple unicast connections for the data flow. When multiple unicast connections are used for the data flow, the remote WTRU may manage service splitting and steering.

[0130] Fig.12 An example method of 3GPP PC5 assisted discovery and N3GPP link establishment is shown. In this embodiment, the remote WTRU and relay WTRU may use the enhanced 3GPP PC5 link establishment procedure to assist the N3GPP access discovery and connection procedure. The terms remote WTRU and relay WTRU may be used. The WTRU may be a peer WTRU participating in direct communication or a peer WTRU participating in communication with a WTRU to a network relay. WTRU1 may be a remote WTRU. WTRU2 may be a WTRU to NW relay and / or have AP functionality.

[0131] A remote WTRU (WTRU1) may be provisioned or receive authorization information 1210 for using an N3GPP connection. A relay WTRU (WTRU2) may be provisioned or receive authorization information 1220 for using an N3GPP connection. The authorization information may include an indicator that N3GPP (e.g., WiFi) is supported. In the case of a WTRU to NW relay scenario, the indicator may be associated with the RSC and the authorization information may include an N3GPP access ID. If configured by the network and if the network does not assign a specific N3GPP access ID, the relay may generate / provide such an access ID.

[0132] The remote WTRU1 may use the ProSe discovery procedure 1230 to discover the relay WTRU2 with N3GPP capabilities.

[0133] The remote WTRU1 may establish a 3GPP PC5 connection with the relay WTRU2 using enhanced link establishment and security procedures to support an additional N3GPP link establishment. The remote WTRU1 may transmit an N3GPP access request message 1240 to the relay WTRU2 indicating that the remote WTRU1 wants to use N3GPP access. The message may be a DCR message and may provide N3GPP access security capabilities (e.g., WPA2 TKIP or AES). The message may be transmitted via a 3GPP connection.

[0134] ProSe authentication and security procedures 1250, 1260 may be used over 3GPP access. The remote WTRU1 and relay WTRU2 may establish the credentials required for N3GPP access security. Relay WTRU2 may generate a shared secret (e.g., WiFi passphrase) for the remote WTRU1 after a successful PC5 direct security mode procedure. Relay WTRU2 may generate an N3GPP access ID (e.g., SSID) if not provided by the network. Alternatively, both WTRUs may derive an N3GPP access shared key (e.g., PSK) after a successful mutual authentication using the ProSe long-term key.

[0135] The relay WTRU2 may transmit N3GPP access information and credential information 1270 to the remote WTRU1. This information may be transmitted in a protected DCA message and may include, for example, an N3GPP access ID, security credentials (e.g., a WiFi passphrase generated as above), and / or an N3GPP security type (e.g., WPA2). A ProSe unicast connection may be established through 3GPP.

[0136] The remote WTRU1 and relay WTRU2 may configure N3GPP access information and credentials (eg, using a pass phrase to generate a PSK) 1280 , 1285 .

[0137] Remote WTRU1 may establish a secure N3GPP connection with relay WTRU2 1290. Remote WTRU1 may establish a secure N3GPP connection with relay WTRU2 using a regular N3GPP association / attachment procedure using the N3GPP access ID and credentials established with relay WTRU2.

[0138] In addition to and alternative to 1250 / 1260, the remote WTRU1 and the relay WTRU2 may establish a N3GPP access connection after the 3GPP PC5 link has been established using the enhanced 3GPP PC5 link modification procedure. The requesting WTRU may indicate, for example, in a Link Modification Request (LMReq) message that the requesting WTRU wants to use N3GPP access. The responding WTRU may provide the N3GPP access ID and credentials as described above, for example, in a Protected Link Modification Response (LMResp) message.

[0139] In subsequent reconnection with relay link modification, remote link modification may use the configured / stored N3GPP access information to establish the ProSe unicast link directly through N3GPP (ie, skipping steps 1240, 1240, 1250, 1270, 1270 and 1280).

[0140] As proposed, the benefits of enabling the remote WTRU and relay WTRU to establish N3GPP access IDs and credentials in an ad hoc manner may be as follows: no impact on the network to maintain N3GPP access information across the remote WTRU and relay WTRU; improved security because the WTRU can frequently update the N3GPP access credential information (e.g., frequently update the WiFi passphrase SSID); an additional layer of confidentiality where the relay WTRU transmits the N3GPP access ID in a protected unicast message. (e.g., the remote WTRU and relay WTRU may use a "hidden SSID"); and automatic "zero configuration" of N3GPP sharing using 3GPP ProSe-capable devices.

[0141] Although features and elements are described above in specific combinations, it will be understood by those of ordinary skill in the art that each feature or element may be used alone or in any combination with other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (sent via a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as built-in hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor associated with software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A method implemented by a relay wireless transmit / receive unit (WTRU), the method comprising: transmitting a message to a network entity indicating support for relaying ProSe services over a non-3GPP (N3GPP) connection; receiving, from the network entity, policy information for WTRU to network relay over N3GPP, wherein the policy information includes a relay service code (RSC), N3GPP identity information, and supported security modes for N3GPP access technologies; Broadcast discovery information via PC5 connection, wherein the discovery information includes the RSC, the N3GPP identity information and the supported security mode of the N3GPP access technology: establishing a PC5 connection for ProSe direct communication with a remote WTRU associated with the RSC, the PC5 connection including a security association with the remote WTRU; performing secure bootstrapping for N3GPP access via the PC5 connection with the remote WTRU, wherein the secure bootstrapping includes exchanging messages with the remote WTRU to share N3GPP security credentials, wherein the N3GPP security credentials are based on a supported security mode of the N3GPP access technology: Establishing an N3GPP connection for ProSe direct communication; as well as A new packet data unit (PDU) session is established or an existing PDU session is modified to relay traffic of the remote WTRU to the network entity.

2. The method of claim 1, wherein the network entity is a 5G core network entity and is one or more of an access and mobility management function (AMF), a session management function (SMF), a policy and control function (PCF), a ProSe server, a direct discovery name management function (DDNMF), or a unified data management (UDM).

3. The method according to claim 1, wherein the policy information comprises: ProSe application and service information, an indication of which N3GPP access technologies are supported, which N3GPP access technologies can be used simultaneously, and security credential information. The method according to claim 3 , wherein the RSC is associated with the ProSe application and service information.

5. The method according to claim 1, further comprising: Receive N3GPP Quality of Service (QoS) information.

6. The method of claim 1, wherein available relay WTRU information is transmitted to the remote WTRU by a policy and control function (PCF), and wherein the available relay WTRU information includes a list of available relay WTRUs, and wherein the list of available relay WTRUs is based on location or time. The method of claim 1 , wherein the secure booting is performed using assistance information received from a ProSe server.

8. The method of claim 1, wherein establishing a new packet data unit (PDU) session or modifying an existing PDU session is based on quality of service (QoS) information.

9. The method according to claim 1, further comprising: Information indicating that the N3GPP connection for ProSe direct communication is established is transmitted to a session management function (SMF).

10. The method according to claim 1, further comprising: receiving information about an aggregate maximum bit rate (AMBR) for a PDU session; as well as Managing the N3GPP connection with the remote WTRU such that a bit rate of the PDU session does not exceed the AMBR.

11. A relay wireless transmit / receive unit (WTRU), the relay wireless transmit / receive unit (WTRU) comprising: Transmitter; Receiver; and A processor, wherein: The transmitter is configured to transmit a message to a network entity indicating support for relaying ProSe services over a non-3GPP (N3GPP) connection; The receiver is configured to receive, from the network entity, policy information for WTRU to network relay over N3GPP, wherein the policy information includes a relay service code (RSC), N3GPP identity information, and a supported security mode for an N3GPP access technology; The processor is configured to broadcast discovery information over a PC5 connection, wherein the discovery information includes the RSC, the N3GPP identity information, and the supported security mode of the N3GPP access technology; The processor is further configured to establish a PC5 connection for ProSe direct communication with a remote WTRU associated with the RSC, the PC5 connection including a security association with the remote WTRU; The processor is further configured to perform secure bootstrapping for N3GPP access via the PC5 connection with the remote WTRU, wherein the secure bootstrapping comprises exchanging messages with the remote WTRU to share N3GPP security credentials, wherein the N3GPP security credentials are based on a supported security mode of the N3GPP access technology; The processor is further configured to establish an N3GPP connection for ProSe direct communication; and The processor is further configured to establish a new packet data unit (PDU) session or modify an existing PDU session to relay traffic of the remote WTRU to the network entity.

12. A relay WTRU according to claim 11, wherein the network entity is a 5G core network entity and is one or more of an access and mobility management function (AMF), a session management function (SMF), a policy and control function (PCF), a ProSe server, a direct discovery name management function (DDNMF) or a unified data management (UDM).

13. The relay WTRU of claim 11 , wherein the policy information comprises: ProSe application and service information, an indication of which N3GPP access technologies are supported, which N3GPP access technologies can be used simultaneously, and security credential information.

14. The relay WTRU of claim 13, wherein the RSC is associated with the ProSe application and service information.

15. The relay WTRU of claim 11, wherein the receiver is further configured to receive N3GPP Quality of Service (QoS) information.

16. The relay WTRU of claim 11, wherein available relay WTRU information is transmitted to the remote WTRU by a policy and control function (PCF), and wherein the available relay WTRU information includes a list of available relay WTRUs, and wherein the list of available relay WTRUs is based on location or time.

17. The relay WTRU of claim 11, wherein the secure booting is performed using assistance information received from a ProSe server.

18. The relay WTRU of claim 11, wherein the processor is further configured to establish a new packet data unit (PDU) session or modify an existing PDU session based on quality of service (QoS) information.

19. The relay WTRU of claim 11, wherein the transmitter is further configured to transmit information indicating that the N3GPP connection for ProSe direct communication is established to a session management function (SMF).

20. The relay WTRU of claim 11, wherein: The receiver is further configured to receive information about an aggregate maximum bit rate (AMBR) for the PDU session; and The processor is further configured to manage the N3GPP connection with the remote WTRU such that a bit rate of the PDU session does not exceed the AMBR.

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