Supporting atsss over non-integrated non-3GPP access

Abstract

Systems, methods, and devices described herein are related to supporting access traffic steering / switching / splitting, ATSSS, over non-integrated non-3GPP access. The WTRU sends a protocol data unit, PDU, session establishment request message including an indication of a PDU session type. The WTRU receives a PDU session establishment response message indicating a multi-leg, ML, configuration and / or an ATSSS rule. The ML configuration includes an internet protocol, IP, address associated with an ATSSS proxy. Based on the indication of the ML configuration and / or the ATSSS rule, the WTRU may select a non-3GPP access node and may direct traffic to the non-3GPP access node based on the ATSSS rule.

Description

SUPPORTING ATSSS OVER NON-INTEGRATED NON-3GPP ACCESSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 553,874, filed February 15, 2024, the contents of which are hereby incorporated by reference herein.BACKGROUND

[0002] Mobile communications using wireless communication continue to evolve. A fifth generation may be referred to as 5G. A previous (legacy) generation of mobile communication may be, for example, fourth generation (4G) long term evolution (LTE).SUMMARY

[0003] Systems, methods, and devices described herein are related to supporting access traffic steering / switching / splitting (ATSSS) over non-integrated non-3GPP access. A wireless transmit / receive unit (WTRU) may include a processor. The WTRU may send a protocol data unit (PDU) session establishment request message. The PDU session establishment request message may include an indication of a PDU session type. The WTRU may receive a PDU session establishment response message. The PDU session establishment response message may indicate a multi-leg (ML) configuration and / or an ATSSS rules. The ML configuration may include an internet protocol (IP) address associated with an ATSSS proxy. Based on the indication of the ML configuration and / or the ATSSS rules, the WTRU may select a non-3GPP access node. The WTRU may direct traffic to the non-3GPP access node based on the ATSSS rules.

[0004] The WTRU may include one or more features. For example, the PDU session type may be an (e.g., simplified) ATSSS PDU session. The (e.g., simplified) ATSSS PDU session may be selected based on UE route selection policy (URSP) rules. The WTRU may send a PDU session modification request message, including an indication of an IP address associated with the WTRU, the non-3GPP access node, and / or an access token. The ATSSS rules may include at least one of splitting, steering, switching, or duplicating the traffic. The WTRU may send a PDU session modification request message including an ATSSS information element (IE) indicating whether a non-3GPP leg associated with the non-3GPP access node is secured. The WTRU may select the PDU session type based on a PDU session policy. The WTRUmay select the PDU session type and / or an access node, such as the non-3GPP access node, based on wireless local area network selection policy (WLANSP) rules. The WLANSP rules may indicate a wireless local area network (WLAN) non-3GPP access node. The selected non-3GPP access node may be the WLAN non-3GPP access node.

[0005] The WTRU may select the PDU session type based on an indication of a public land mobile network (PLMN) type or a PLMN ID. The PDU session establishment response message may include an indication to secure the traffic directed to the non-3GPP access node. The indication may indicate that at least one of an internet protocol security (IP Sec) tunnel, a generic routing encapsulation (GRE) tunnel, or a QUID tunnel.

[0006] A network node may include a processor. The network node may be configured to receive, from a WTRU, a PDU session establishment request message. The PDU session establishment request message may include an indication of a PDU session type. The network node may send a PDU session establishment response message. The PDU session establishment response message may indicate an ML configuration and / or an ATSSS rules. The ML configuration may include an IP address associated with an ATSSS proxy. The network node may receive a PDU session modification request message including an indication of an IP address associated with a WTRU, a non-3GPP access node, and / or an access token.

[0007] Based on the received PDU session modification request message, the network node may determine an updated ML configuration. The network node may send the updated ML configuration to the WTRU.

[0008] The network node may include one or more features. For example, the PDU session type may be an (e.g., simplified) ATSSS PDU session. The ATSSS rules may include at least one of splitting, steering, switching, or duplicating traffic. The PDU session establishment response message may include an indication to secure the traffic directed to the non-3GPP access node. The indication may indicate at least one of an IP Sec tunnel, a GRE tunnel, or a QUID tunnel. The PDU session modification request message may include an ATSSS IE (e.g., a simplified ATSSS IE) indicating whether a non-3GPP leg associated with the non-3GPP access node is secured.

[0009] Systems, methods, and instrumentalities are described herein related to supporting ATSSS over non-integrated non-3GPP access. A WTRU may (e.g., be configured to) perform one or more actions. The WTRU may obtain enhanced URSP rules and enhanced WLANSP rules. The WTRU may select a PDU session type based on a PDU session selection condition. The WTRU may send a PDU session establishment request and receive, based on the PDU session establishment request, a PDU session establishment response including ATSSS rules and / or an ML configuration. The ATSSS rules may includea steering mode. The WTRU may select a non-3GPP access node. The WTRU may direct traffic (e.g., splitting, steering, switching, or duplicating the traffic) based on the ATSSS rules.

[0010] The PDU session selection condition may be one or more of a traffic type or a PLMN of non- 3GPP access. The PDU session establishment request may include a PDU session type and / or a condition at the WTRU.

[0011] The WTRU may send a PDU Session Modification request and receive a PDU Session Modification response. The PDU Session Modification request may include a simplified ATSSS IE, for example indicating whether a non-3GPP leg associated with the non-3GPP access node is secured. The PDU Session Modification response may include a simplified ATSSS IE.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented.

[0013] FIG. 1 B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A according to an embodiment.

[0014] FIG. 1 C is a system diagram illustrating an example radio access network (RAN) and an example core network (ON) that may be used within the communications system illustrated in FIG. 1 A according to an embodiment.

[0015] FIG. 1 D is a system diagram illustrating a further example RAN and a further example ON that may be used within the communications system illustrated in FIG. 1A according to an embodiment.

[0016] FIG. 2 depicts an example WTRU with 3GPP and non-3GPP access.

[0017] FIG. 3 depicts an example WTRU with 3GPP and non-3GPP access.

[0018] FIG. 4 depicts example of non-integrated non-3GPP access and access traffic steering / switching / splitting (ATSSS) functionality in a UPF.

[0019] FIG. 5 depicts example of non-integrated non-3GPP access and ATSSS functionality in an AS.

[0020] FIG. 6 depicts example of non-integrated non-3GPP access and ATSSS functionality in a third- party server.

[0021] FIGS. 7A and 7B depict an example of multi-leg (ML) protocol data unit (PDU) session establishment.DETAILED DESCRIPTION

[0022] FIG. 1 A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0023] As shown in FIG. 1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a ON 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or a “STA”, may be configured to transmit and / or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE.

[0024] The communications systems 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the I nternet 110, and / or the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will beappreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0025] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e. , one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0026] 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).

[0027] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed UL Packet Access (HSUPA).

[0028] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0029] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access , which may establish the air interface 116 using New Radio (NR).

[0030] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., an eNB and a gNB).

[0031] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0032] The base station 114b in FIG. 1 A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In 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 femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0033] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, whichmay be utilizing a NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0034] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 may include circuit- switched telephone networks that provide 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), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0035] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0036] FIG. 1 B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1 B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0037] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. 1 B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0038] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0039] Although the transmit / receive element 122 is depicted in FIG. 1 B as a single element, 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.

[0040] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and I EEE 802.11 , for example.

[0041] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), 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, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0042] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include oneor more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0043] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable locationdetermination method while remaining consistent with an embodiment.

[0044] The processor 118 may further be coupled to other peripherals 138, which may include one or more software 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 e-compass, a satellite transceiver, a digital camera (for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0045] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and / or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).

[0046] FIG. 1 C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0047] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0048] Each of the eNode-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, scheduling of users in the UL and / or DL, and the like. As shown in FIG. 1 C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0049] The CN 106 shown in FIG. 1 C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0050] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, 160c 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, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0051] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the 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 user planes during inter- eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0052] 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.

[0053] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. Inaddition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0054] Although the WTRU is described in FIGS. 1 A-1 D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0055] In representative embodiments, the other network 112 may be a WLAN.

[0056] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in to and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to- peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11 z tunneled DLS (TDLS). A WLAN using an Independent BSS (I BSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an “ad- hoc” mode of communication.

[0057] When using the 802.11 ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0058] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0059] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0060] Sub 1 GHz modes of operation are supported by 802.11af and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.11 af and 802.11 ah relative to those used in 802.11 n, and 802.11 ac. 802.11 af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non- TVWS spectrum. According to a representative embodiment, 802.11 ah may support Meter Type Control / Machine-Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0061] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11 n, 802.11 ac, 802.11 af, and 802.11 ah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11 ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0062] In the United States, the available frequency bands, which may be used by 802.11 ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. InJapan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11 ah is 6 MHz to 26 MHz depending on the country code.

[0063] FIG. 1 D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0064] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0065] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0066] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such aseNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0067] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E- UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. 1 D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0068] The CN 115 shown in FIG. 1 D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0069] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and / or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0070] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providingdownlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernetbased, and the like.

[0071] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet- switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0072] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0073] In view of Figures 1 A-1 D, and the corresponding description of Figures 1 A-1 D, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0074] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or may performing testing using over-the-air wireless communications.

[0075] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example,the emulation devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be testing equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0076] In an example, a WTRU may be interested in establishing an access traffic steering / switching / splitting (ATSSS) PDU session. The ATSSS PDU session may enable ATSSS over nonintegrated non-3GPP access. The WTRU may be provided with enhanced UE (e.g., WTRU) route selection policy (URSP) rules for selecting an ATSSS PDU session and may be provided with a wireless local area network selection policy (WLANSP) rules (e.g., enhanced WLANSP rules) for selecting a non-integrated non-3GPP access network / node. The WTRU may select the type of PDU session based on PDU session selection criteria (e.g., traffic type, public land mobile network (PLMN) of non-3GPP access, and / or the like). The WTRU may send a PDU session establishment request to establish an ATSSS PDU session (e.g., which may be a simplified ATSSS PDU session), which may include one or more (e.g., simplified) ATSSS lEs (e.g., PDU session type, conditions at the WTRU, and / or the like). The one or more (e.g., simplified) ATSSS lEs included in the PDU session establishment request may be included in an ML PDU session IE. In examples, the WTRU may send a PDU session establishment message including an indication of a PDU session type. The WTRU may select the PDU session type based on a PDU session rules (e.g., PDU session selection criteria). In examples, the WTRU may select the PDU session type and / or a non-3GPP access node, based on WLANSP rules. The WLANSP rules may indicate a WLAN non-3GPP access node. In examples, the WTRU may select the PDU session type based on an indication of a PLMN type or a PLMN ID.

[0077] The PDU session type may be an ATSSS PDU session. The ATSSS PDU session may be selected based on URSP rules. The PDU session establishment request message may include an ATSSS information element (IE) indicating whether a non-3GPP leg associated with the non-3GPP access node is secured. The WTRU may receive a PDU session establishment response that may include one or more ATSSS rules and / or ATSSS lEs, which may be simplified ATSSS lEs (e.g., an IP address of a UPF, a request (e.g., need) for an internet protocol security (IP sec) tunnel, and / or the like). The (e.g., simplified) ATSSS lEs included in the PDU session establishment response may be included in an ML configuration rules IE. In examples, the PDU session establishment response message may indicate an ML configuration and / or an ATSSS rules. The ML configuration may include an IP address associated with an ATSSS proxy. In examples, the PDU session establishment response message may include an indication to secure traffic directed to the non-3GPP access node. The indication to secure traffic may indicate at least one of an IPSec tunnel, a GRE tunnel, or a QUIC tunnel. The ATSSS rules may include steering modes for ATSSS and / or simplified ATSSS. The WTRU may select a non-3GPP access node and / or may be assigned an IP address over the non-3GPP access leg. In examples, the WTRU may select a non-3GPP access node based on the indication of the ML configuration. The WTRU may direct traffic to the non-3GPP access node based on the ATSSS rules.

[0078] A WTRU may send a PDU session modification request, which may include one or more ATSSS lEs and / or simplified ATSSS lEs (e.g., an indication of whether the non-3GPP leg is secured). The (e.g., simplified) ATSSS lEs included in the PDU session modification request may be included in a non-3GPP access IE. In examples, the PDU session modification request may include an indication of an IP address associated with the WTRU, the non-3GPP access node, and / or an access token. The WTRU may receive a PDU session modification response, which may include ATSSS lEs and / or simplified ATSSS lEs. The (e.g., simplified) ATSSS lEs included in the PDU session modification response may be included in an ML configuration rules IE. The WTRU may split, steer, switch, and / or duplicate traffic according to the configured ATSSS rules.

[0079] ATSSS may be implemented (e.g., in 3GPP cellular networks). WTRUs may be capable of both 3GPP access and non-3GPP access. This capability may provide flexibility to network operators in determining which access to use for a service data flow.

[0080] FIG. 2 depicts an example WTRU with 3GPP and non-3GPP access. As shown in FIG. 2, a WTRU using both accesses may be requested (e.g., required) to establish independent single-access (SA) protocol data unit (PDU) sessions over one or more accesses (e.g., over each of the accesses). Such an architecture may not take advantage of the flexibility provided by the capability of the WTRU to support both 3GPP access and non-3GPP access.

[0081] FIG. 3 depicts an example WTRU with 3GPP and non-3GPP access. As shown in FIG. 3, the notion of a multi-access PDU session may be introduced, for example, allowing uplink and downlink traffic of a service data flow to be more easily steered, switched, or split between accesses. A multi-access PDU session may be a PDU session whose traffic may be sent over a 3GPP access, over a non-3GPP access, or over both accesses.

[0082] The architecture (e.g., as shown in FIG. 3) may allow one or more of the following ATSSS functionality: access traffic steering, access traffic switching, or access traffic splitting.

[0083] Access traffic steering may be a procedure that selects an access network for a data flow (e.g., a new data flow) and transfers the traffic of this data flow over the selected access network. Access traffic steering may be applicable between 3GPP and non-3GPP accesses.

[0084] Access traffic switching may be a procedure that moves traffic of an ongoing data flow from a first (e.g., one) access network to a second (e.g., another) access network, for example, to maintain the continuity of the data flow. Access traffic switching may be applicable between 3GPP and non-3GPP accesses.

[0085] Access traffic splitting may be a procedure that splits the traffic of a data flow across multiple access networks. When traffic splitting is applied to a data flow, (e.g., some) traffic of the data flow may be transferred via a first (e.g., one) access and (e.g., some) other traffic of the (e.g., same) data flow may be transferred via another access. Access traffic splitting may be applicable between 3GPP and non-3GPP accesses.

[0086] The steering functionality in an ATSSS-capable WTRU may steer, switch, and / or split the MA PDU session traffic across 3GPP access and non-3GPP access. Two steering functionalities may be standardized. A (e.g., first) steering functionality may be a high-layer steering functionality, which may operate above the Internet Protocol (IP) layer. The steering functionality may be based on a multi-path TCP (MPTCP) protocol and / or may be referred to as MPTCP functionality. This functionality may be applicable to TCP traffic. Another (e.g., a second) steering functionality may be a low-layer steering functionality, which may operate below the IP layer. A type (e.g., one type) of low-layer steering functionality may be provided (e.g., defined) and / or may be referred to as ATSSS low-layer functionality, or ATSSS-LL functionality. The ATSSS-LL functionality may be applicable to Ethernet and IP (e.g., TCP and UDP). The steering functionality may be functionality that exists in both the WTRU and the UPF (e.g., the endpoints of a PDU session).

[0087] A number of steering modes may be allowed (e.g., with the above steering functionality). The steering mode may determine how the traffic of the matching service data flow may be distributed across 3GPP and non-3GPP accesses. The steering modes supported may include one or more of: active standby, the smallest delay, a load balancing, or priority based.

[0088] Active standby steering mode may be used to steer traffic on a first (e.g., one) access (e.g., the active access) when this access is available and to switch the traffic to a second (e.g., the other) access (e.g., the standby access) when the active access becomes unavailable.

[0089] A low and / or small delay steering mode (e.g., smallest delay steering mode) may be used to steer traffic to the access that is determined to have a small round-trip time (RTT) (e.g., the smallest RTT). WTRU and UPF may measure the RTT, for example, in order to determine which access has a low RTT (e.g., the lowest RTT). A small delay (e.g., smallest delay) may (e.g., only) be used for the non-guaranteed bit rate (non-GBR) service data flow (SDF).

[0090] Load balancing steering mode may be used to split traffic across both accesses according to a percentage of how much traffic may be sent over 3GPP access and over non-3GPP access. Loadbalancing may (e.g., only) be applicable to non-GBR SDF.

[0091] A priority based steering mode may be used to steer the traffic matching a policy, charging, and control (PCC) rule to the high-priority access until this access is determined to be congested. In examples, the traffic may (e.g., also) be sent to the low-priority access (e.g., the traffic may be split over the two accesses). The traffic (e.g., it) may be (e.g., may only be) used for the non-GBR SDF.

[0092] Steering modes may be enhanced. For example, for the load balancing steering mode, 3GPP may add a steering mode indicator, which may indicate that the WTRU may change the default steering parameters provided in the steering mode component and may adjust the traffic steering based on its own decisions. At least one (e.g., only one) of the following steering mode indicators may be provided: an autonomous load-balance indicator or a WTRU-assistance indicator.

[0093] When the autonomous load-balance indicator is provided, the WTRU may ignore the percentages in the steering mode component (e.g., the default percentages provided by the network) and / or may autonomously determine its own percentages for traffic splitting (e.g., in a way that may maximize the aggregated bandwidth in the uplink direction).

[0094] If / when the WTRU-assistance indicator is provided by the network, the indicator may indicate that (a) the WTRU may decide how to distribute the uplink (UL) traffic of the matching SDF based on the WTRU's internal state (e.g., when the WTRU is in the internal state, has a lower battery level, and / or the like), and / or that (b) the WTRU may inform the UPF how it decided to distribute the UL traffic of the matching SDF. With an indicator (e.g., this indicator provided), the WTRU may distribute the UL traffic as indicated by the network.

[0095] For the load balancing steering mode, 3GPP may (e.g., also) add a threshold value. A threshold value may be (e.g., either) a value for RTT or a value for packet loss rate (PLR). The threshold values may be applicable to both accesses and / or may be applied by the WTRU and / or UPF. If / when at least one measured parameter (e.g., RTT or PLR) on an (e.g., one) access exceeds the provided threshold value, the WTRU and / or UPF may stop sending traffic on this access and / or may continue sending traffic on this access (e.g., but may (e.g., should) reduce the traffic on this access by an amount (e.g., an implementation-specific amount) and may send the amount of reduced traffic on the other access). When measured parameters (e.g., RTT and PLR) for both accesses do not exceed the provided threshold values, the WTRU and / or UPF may apply split percentages (e.g., fixed split percentages).

[0096] For the priority-based steering mode, 3GPP may (e.g., also) add a threshold value. A threshold value may be either a value for RTT or a value for PLR. The threshold values may be applicable to bothaccesses and / or may be applied by the WTRU and / or UPF. These threshold values may (e.g., should) be considered by WTRU and / or UPF to determine if / when an access becomes congested. For example, if / when a measured parameter (e.g., RTT or PLR) on an (e.g., one) access exceeds the provided threshold value, the WTRU and / or UPF may consider this access as congested and / or may (e.g., also) send the traffic to the low priority access.

[0097] Rules may be used at (e.g., both) the WTRU and / or the UPF (e.g., to enable the steering modes for one or more of the steering functionalities). These rules may be generated by the session management function (SMF), for example, based on information known to the policy control function (PCF). These rules may be sent to the WTRU (e.g., ATSSS rules) for determining switching functionality and / or switching mode to use for UL traffic, and may be sent to the UPF (N4 rules) to determine switching functionality and / or switching mode to use for downlink (DL) traffic.

[0098] A performance measurement function (PMF) protocol (e.g., to support some of the steering modes) may be used at WTRU and UPF to make the measurements for the switching mode decisions (e.g., round trip time measurements, access availability / unavailability report, PLR, and / or the like).

[0099] A redundant steering mode may be introduced, where the traffic may be duplicated over both accesses, for example, to better meet the parameters (e.g., requirements) of service data flows. At least two types of redundant steering modes may be provided. These types may deal with the dynamicity of the duplication and may be categorized as static or dynamic.

[0100] Static redundant steering modes may be used as follows. The network may configure the WTRU and / or UPF with information as to which access is the primary access (e.g., over which packets are transmitted) and / or which access is the secondary access. If no primary access is configured, then the UPF and / or WTRU may duplicate packets over both accesses (e.g., effectively 100% duplication). If the network configures a primary access, the UPF and / or WTRU may send traffic over the primary access and decide (e.g., using a non-standardized algorithm), whether to duplicate over the secondary access.

[0101] Dynamic redundant steering modes may be provided. For example, the duplication decision may be per packet of a flow, and / or the decision may be based on measurements and criteria. It may (e.g., only) be used for the non-GBR SDF.

[0102] The capability to allow the UPF to suspend and / or resume traffic duplication (e.g., based on load at the UPF) may be introduced. The UPF may make the decision and / or may inform the WTRU via a PMF exchange.

[0103] Feature(s) associated with non-3GPP access in cellular networks are provided herein. Cellular networks may support modes of non-3GPP access integration.

[0104] In a first mode (e.g., one mode), the integration may be done through an interworking or gateway node (e.g., trusted non-3GPP gateway function (TNGF) and non-3GPP interworking function (N3IWF)). These nodes may forward control plane and user plane traffic of a WTRU over the core network. The WTRUs may have a secure connection to these gateways (e.g., an IP Sec tunnel), the gateway may have an N2 interface to the AMF (e.g., for control plane traffic), and / or an N3 interface to the UPF (e.g., for user plane traffic). This may be the mode used for ATSSS PDU sessions. These non-3GPP access networks may be integrated with the core network and / or may be referred to as integrated non-3GPP access networks (e.g., as used herein).

[0105] In a second mode, the integration may be done at the access stratum level and / or the splitting of traffic across 3GPP and non-3GPP may be done at the WTRU and the RAN nodes. This mode may be similar to dual connectivity. The core network may not be aware of whether the traffic has been received over a 3GPP access or a non-3GPP access.

[0106] In a third mode, the integration may be done by offloading some traffic over the non-3GPP access. In this mode, traffic matching a filter criterion may be offloaded to the non-3GPP access and the traffic may not traverse the core network. The core network may be unaware of this traffic. This mode may not be used for ATSSS.

[0107] Feature(s) associated with ATSSS with non-integrated non-3GPP access are provided herein.

[0108] An ATSSS mode may not rely on integrated non-3GPP access. In such an ATSSS mode, the non-3GPP access leg may not be connected to a gateway function.

[0109] FIG. 4 depicts an example of a non-integrated non-3GPP access and ATSSS functionality in a UPF. FIG. 5 depicts an example of non-integrated non-3GPP access and ATSSS functionality in an AS. FIG. 6 depicts an example of a non-integrated non-3GPP access and ATSSS functionality in a third-party server.

[0110] The network side ATSSS functionality may be located at the UPF (e.g., as shown in FIG. 4), at the application server or application function (e.g., as shown in FIG. 5), in a third-party server or node in an external network (e.g., as shown in FIG. 6), or in another network function in the core network.

[0111] One or more WTRUs may support non-3GPP access. The WTRUs may use a (e.g., this) non- 3GPP access in a standalone manner, for example, for an application (e.g., dedicated to particular applications). In examples, the mobile operator network may not be aware that the WTRU application is using a non-3GPP access. The WTRUs may (e.g., alternatively) use this non-3GPP access in an integrated manner and / or may rely on a connection to the core network through gateway functions (e.g., specialized gateway functions, such as the N3IWF and TNGF (e.g., for 5GC)). A WTRU may rely on an integrated non-3GPP access. As WTRU(s) are integrated, this may allow the network to use ATSSS tosplit / switch / steer / duplicate traffic of a traffic flow across the 3GPP access and the integrated non-3GPP access.

[0112] Operators may not support integrated access or may not rely on the gateway functionality to allow integrated access. For example, this may be because mobile operators may (e.g., want to) avoid using IP sec or request that (e.g., requiring) the gateway to support the N2 interface. A WTRU may not be able to take advantage of the benefits of ATSSS (e.g., with respect to loss and latency).

[0113] Feature(s) associated with allowing ATSSS over a non-integrated non-3GPP leg may be provided herein. Feature(s) described herein may be associated with a WTRU selecting a first type of ATSSS (e.g., which may be referred to as simplified ATSSS) over other types of multi-access for splitting, steering, switching, or duplicating PDUs of a traffic flow. Feature(s) described herein may be associated with a WTRU establishing an (e.g., a simplified) ATSSS MA-PDU session. Feature(s) described herein may be associated with a WTRU registering to the network over a non-integrated non-3GPP access.

[0114] The term access node may be used to refer to the node providing connectivity to a WTRU. An access node may be a RAN node or a 3GPP node. For example, a gNB that may support NR, or an eNB that may support LTE. An access node may be a non-3GPP node. For example, a WLAN access point may support the IEEE 802.11 protocol, or a LAN access point may support Ethernet.

[0115] The term external data network may be used to refer to a network external to the mobile operator core network. For example, this may be the public internet.

[0116] The terms mobile operator core network, core network, and / or 5GC may be used interchangeably herein. The terms may refer to the functionality of the mobile operator network which controls the user plane and control plane operations. For example, the core network may provide traffic handling, as well as billing, location, and security (e.g., ensuring that services may be accessed by the people and devices that have permission to do so and that they are accurately billed for what they use).

[0117] An IE may be used to refer to (e.g., a set of) one or more elements of information that may be grouped under an IE name (e.g., one common IE name). An IE may include additional lEs (e.g., other lEs).

[0118] A simplified ATSSS may be used to denote an (e.g., form of) ATSSS where traffic over the non- 3GPP leg bypasses the core network. In an (e.g., simplified) ATSSS, the WTRU may (e.g., still be requested (e.g., required) to) be authenticated by the core network. In an (e.g., simplified) ATSSS, the WTRU may (e.g., still be requested (e.g., required) to) be registered with the core network over the non- 3GPP access.

[0119] An integrated non-3GPP may be used to refer to a non-3GPP access where the non-3GPP access node is connected to the core network via an interworking or gateway function. For example, in anuntrusted alternative, the non-3GPP access node may be connected to an N3IWF. For example, in a trusted alternative, the non-3GPP access node may be connected to a TNGF.

[0120] A non-integrated non-3GPP may be used to refer to a non-3GPP access where the non-3GPP access node is not connected to the core network via an interworking or gateway function. User plane traffic may be forwarded by the access node directly to the external data network.

[0121] An (e.g., simplified) ATSSS PDU session may be used to refer to a PDU session where traffic may be carried over a (e.g., one) 3GPP access leg, over a non-integrated non-3GPP access leg, and / or over both 3GPP access leg and a non-integrated non-3GPP access leg. The (e.g., simplified) ATSSS PDU session may be a MA PDU session with a 3GPP access leg and a non-integrated non-3GPP access leg. The (e.g., simplified) ATSSS PDU session may be an SA PDU session, with a 3GPP access leg and a linked or associated non-integrated non-3GPP access leg.

[0122] A multi-leg PDU (ML PDU) session type may be used to refer to the type of PDU session. For example, this may be (e.g., one of) an MA PDU session based on ATSSS, an MA PDU session based on DualSteer, (e.g., at least) two linked SA PDU sessions (e.g., a MA PDU session based on at least two linked SA PDU sessions), a SA PDU session (e.g., an MP PDU session based on a SA PDU session), and a linked or associated non-integrated non-3GPP access leg, or an (e.g., simplified) ATSSS PDU session (e.g., an MA PDU session based on a (e.g., simplified) ATSSS PDU session).

[0123] An ML PDU session type determination procedure may be used to refer to the procedure at the WTRU to determine the ML PDU session type.

[0124] One or more ML configuration rules may be used to refer to the configuration provided to the WTRU in order to allow steering, switching, splitting, and / or duplication over access legs (e.g., the two access legs). For example, for an MA PDU session with (e.g., or based on) ATSSS, ML configuration rules may correspond to ATSSS rules. For an MA PDU session with (e.g., or based on) DualSteer, ML configuration rules may correspond to DualSteer rules. For an MA PDU session with (e.g., or based on) an (e.g., simplified) ATSSS, ML configuration rules may include an IP address of the ATSSS proxy, an indication whether the connection to the node hosting the ATSSS proxy may be (e.g., needs to be) secured, an indication of a mechanism that may be used to secure the connection to the node hosting the ATSSS proxy, an indication of a (e.g., preferred) characteristic(s) of the non-3GPP access network / node, and / or the like.

[0125] An ATSSS proxy may be used to refer to the functionality and / or logic where the ATSSS downlink traffic is split / steered / switched / duplicated across the (e.g., two) access legs, and / or where the uplink traffic received from the (e.g., two) access legs is merged and / or recombined. The ATSSS proxy may be located in the PDU session anchor (PSA) UPF, in an intermediate UPF, in a (e.g., dedicated)network function in the mobile core network, in an edge network node, or in a server in any external data network (e.g., the internet).

[0126] A (e.g., simplified) ATSSS IE may indicate (e.g., may be used to refer to) one or more lEs related to a (e.g., simplified) ATSSS PDU session. One or more (e.g., simplified) ATSSS lEs may be used in a PDU session establishment request and / or may be referred to as an ML PDU session IE. One or more (e.g., simplified) ATSSS lEs may be used in a PDU session establishment response and / or a PDU session modification response and / or may be referred to as an ML configuration rules IE. One or more (e.g., simplified) ATSSS lEs may be used in a PDU session modification request and / or may be referred to as a non-3GPP access IE.

[0127] The WTRU may perform an action (e.g., selecting, discovering, and / or connecting) with or in relation to a non-3GPP access network and / or node. For a (e.g., some) non-3GPP accesses (e.g., such as WLAN), the action (e.g., selecting, discovering, and / or connecting) described may be with respect to a WLAN network. For (e.g., other) non-3GPP accesses (e.g., such as Bluetooth), the action described may be with respect to a Bluetooth node or device.

[0128] Feature(s) associated with one or more of the following may be provided herein. A WTRU may establish an (e.g., simplified) ATSSS PDU session. Enhanced URSP rules and WLANSP rules may enable (e.g., simplified) ATSSS PDU sessions. A WTRU may determine which ML PDU session is suited for the underlying conditions at the WTRU and / or the type of traffic. A modified PDU session establishment procedure may be used to set up an (e.g., simplified) ATSSS PDU session. A WTRU may select a nonintegrated non-3GPP access network and / or node, for example, based on guidance from the network. A WTRU may register over a non-integrated non-3GPP access.

[0129] Feature(s) (e.g., as described herein) may allow the network operators to take advantage of ATSSS even if the operator’s core network does not support non-3GPP gateway functions (e.g., such as TNGF and N3IWF), and / or may allow the operator control over what PDU session type (e.g., the PDU session type) the WTRU selects for an ML PDU session.

[0130] FIGS. 7A and 7B depict an example of an ML PDU session establishment. As shown in FIG. 7, an ML PDU session of type (e.g., a simplified) ATSSS may be established (e.g., as illustrated with the depicted flow).

[0131] As shown in FIG. 7A at 0, a WTRU may be provided (e.g., provisioned with and / or include) URSP rules enhanced to support ML PDU session types and / or may be provided (e.g., provisioned with and / or include) WLANSP rules to support non-integrated non-3GPP access networks and / or nodes.

[0132] At 1 , the WTRU may start an application. The WTRU may be configured to route the application to an ML PDU session.

[0133] At 2, the WTRU may determine the ML PDU session type to use for an application (e.g., this application). With reference to FIGS. 7A and 7B, in examples, one or more operations (e.g., subsequent operations) may assume that the WTRU selects an (e.g., simplified) ATSSS PDU session.

[0134] At 3, the WTRU may send a PDU session establishment request message over the 3GPP leg. The PDU session establishment request may include an ML PDU session IE. The PDU session establishment request message may indicate a PDU session type. The PDU session type may be an (e.g., simplified) ATSSS PDU session. The (e.g., simplified) ATSSS PDU session may be selected based on the URSP rules. In examples, the WTRU may select the PDU session type based on WLANSP rules. The WLANSP rules may indicate a WLAN non-3GPP access node.

[0135] At 4, the SMF may determine the configuration of the ML PDU session.

[0136] At 5, the SMF may provide the ML PDU session configuration to the WTRU via a PDU session establishment accept message (e.g., in an ML configuration rules IE) and / or to the node hosting the ATSSS proxy. For example, if the ATSSS proxy is hosted in the UPF, the ML configuration rules may be provided via an (e.g., N4) session establishment / modification request message (e.g., in N4 rules). In examples, if the ATSSS proxy is hosted in an entity outside the core network, the SMF may send a message to this entity via the UPF. In examples, the PDU session establishment response message may indicate an ML configuration and / or a ATSSS rules. The ML configuration may include an IP address associated with an ATSSS proxy. In examples, the PDU session establishment response message may include an indication to secure the traffic directed to the non-3GPP access node. The indication may indicate at least one of an IP Sec tunnel, a GRE tunnel, or a QUID tunnel.

[0137] As shown in FIG. 7B at 6, the WTRU may select a non-3GPP access node (e.g., for example based on information in ML configuration rules IE). The WTRU may be assigned an IP address to use over the non-3GPP access leg. The WTRU may (e.g., additionally) generate an access token. The access token may be used in communications between the WTRU and the node hosting the ATSSS proxy.

[0138] At 7, the WTRU may send a PDU session modification request message to the SMF, for example with a non-3GPP access IE. The PDU session modification request message may include an indication of an IP address associated with the WTRU, the non-3GPP access node, and / or an access token. In examples, the PDU session modification request message may include an ATSSS IE (e.g., a simplified ATSSS IE) indicating whether a non-3GPP leg associated with the non-3GPP access node is secured.

[0139] At 8, the SMF may determine updated ML configuration rules (e.g., based on the non-3GPP access IE from 7). The SMF may (e.g., then) send the updated ML configuration rules to the WTRU (e.g., via a PDU session modification accept message) and / or to the node hosting the ATSSS proxy. Forexample, if the ATSSS proxy is hosted in the UPF, the updated ML configuration rules may be sent to the UPF (e.g., via N4 session modification message).

[0140] At 9, the WTRU may complete the PDU session setup (e.g., if necessary). The WTRU may establish a tunnel to the node hosting the ATSSS proxy (e.g., based on the ML configuration rules). For example, this may be an IP sec association, a generic routing encapsulation (GRE) tunnel, or a QUIC tunnel.

[0141] At 10, the WTRU and the UPF may use the (e.g., two) access legs for steering, switching, splitting, and / or duplicating across the (e.g., two) access legs.

[0142] A WTRU may be provided with WLANSP rules and / or URSP rules (e.g., enhanced) to support ML PDU session types. A WTRU may be provided URSP rules, for example, to (e.g., help) determine where (e.g., which PDU session) to route traffic from an application. If no such PDU session exists (e.g., already exists), the establishment of a (e.g., new) PDU session may be triggered.

[0143] A (e.g., each) URSP rule may include (e.g., contain) a rule precedence, a traffic descriptor (e.g., to help identify the application), and / or a list of route selection descriptors. A route selection descriptor may include (e.g., contain) one or more components (e.g., session and service continuity (SSC) mode, DNN selection, non-seamless offload indication, access type preference, and / or the like).

[0144] To support multiple ML PDU session types, the URSP rule may include one or more of the following (e.g., additional) route selection descriptor components: ML PDU session type preference, ML indication, or ML PDU session type restriction.

[0145] The URSP rule may be enhanced to include an ML PDU session type preference. An ML PDU session type preference may indicate the type of ML PDU session (e.g., if the WTRU needs to establish an ML PDU session). For example, a ML PDU session type preference may indicate an MA PDU session based on ATSSS, an MA PDU session based on DualSteer, multiple (e.g., two) single access PDU sessions (e.g., a MA PDU session based on multiple (e.g., two) single access PDU sessions), or an (e.g., simplified) ATSSS PDU session (e.g., a MA PDU session based on an (e.g., simplified) ATSSS PDU session).

[0146] An ML PDU session type preference may (e.g., alternatively) be provided by enhancing the existing route selection descriptor components. For example, the access type preference may include an additional option (e.g., non-integrated non-3GPP) to indicate that a PDU session may (e.g., should) be established as an (e.g., simplified) ATSSS PDU session.

[0147] The URSP rule may be enhanced to include an ML indication. A ML indication may be an indication to a WTRU, that the PDU session is a ML PDU session, and / or (e.g., but) that the WTRU may (e.g., should) determine the ML PDU session type.

[0148] The URSP rule may be enhanced to include a ML PDU session type restriction. The ML PDU session type restriction may indicate the PDU session type(s) that may be (e.g., should be) avoided for the PDU session. An ML PDU session type restriction may be an indication to a WTRU that the ML PDU session may (e.g., should) be restricted based on the type of the registered PLMN (e.g., a home PLMN versus a visited PLMN use different ML PDU session type).

[0149] A WTRU may be provided WLANSP rules, for example to help select and / or reselect a WLAN access network. The rules may (e.g., only) apply to non-3GPP access nodes of type WLAN. The rules may be extended by including a non-integrated non-3GPP indication, which may indicate to the WTRU that the WLAN network is suitable for non-integrated non-3GPP access.

[0150] A WTRU may determine the ML PDU session type to use. A WTRU may be registered to a PLMN and may determine which ML PDU session type to use for the application. The WTRU may use a ML PDU session type determination procedure.

[0151] In a first ML PDU session type determination procedure, the WTRU may be pre-configured with a mapping between the application and an ML PDU session type. For example, the mapping may be included in the (e.g., pre-configured) URSP rules available to the WTRU.

[0152] In a second ML PDU session type determination procedure, the WTRU may receive a mapping between the application and ML PDU session type (e.g., from the core network). For example, the mapping may be included in the URSP rules signaled to the WTRU.

[0153] In (e.g., both) the first ML PDU session type determination procedure and / or the second ML PDU session type determination procedure, the URSP rule may include a traffic descriptor to (e.g., help) identify the application and a route selection descriptor with an ML PDU session type preference component.

[0154] In a third ML PDU session type determination procedure, the WTRU may receive an indication that the application may use an ML PDU session and / or that the decision on which type may be made by the WTRU. The WTRU may receive the indication in the URSP rule. The decision may be based on at least one of a WTRU ML capability, a network ML capability, a condition at the WTRU, a network preference, a type of application or properties of the application, an existing WTRU connectivity, the type of PLMN, a PLMN ID, or a supported non-3GPP.

[0155] The WTRU may determine the type of ML PDU session based on a WTRU ML capability (e.g., the ML PDU session types supported by the WTRU). For example, a (e.g., some) WTRU(s) may (e.g., may only) support a subset of the ML PDU session types.

[0156] The WTRU may determine the type of ML PDU session based on a network ML capability (e.g., the ML PDU session types supported by the network). The WTRU may obtain this PLMN information from broadcast system information and / or from a (e.g., dedicated) signaling exchange with the network (e.g.,registration accept, DL NAS transport, configuration update command, PDU session establishment accept, and / or the like). The WTRU may (e.g., alternatively) be pre-configured with this network capability (e.g., the WTRU may know that a network (e.g., certain networks) supports simplified ATSSS PDU sessions). The network ML capability may (e.g., also) be implicitly determined by the WTRU (e.g., for example, based on network support of TNGF and / or network support of N3I WF).

[0157] The WTRU may determine the type of ML PDU session based on condition(s) at the WTRU. For example, condition(s) may be based on at least one of a battery status (e.g., if battery power is below a threshold, WTRU may use an MA PDU based on an (e.g., simplified) ATSSS PDU session), whether WTRU is mains powered (e.g., if mains powered, WTRU may use MA PDU with (e.g., or based on) DualSteer), a user preference (e.g., a user may enter through a user interface that it prefers to use simplified ATSSS PDU session), or a signal quality (e.g., select PDU session with a non-3GPP leg if the non-3GPP quality is above a threshold). For example, the decision may be based on a combination of condition(s).

[0158] The WTRU may determine the type of ML PDU session based on a network preference (e.g., the network may support a number of ML PDU session types, but it may prefer not to use certain types (e.g., other ML PDU session types)). For example, the network preference may limit the number of non-3GPP accesses to the core network by WTRUs using an MA PDU session based on ATSSS. The network may provide a preference to the WTRU (e.g., for example through broadcast system information and / or from a (e.g., dedicated) signaling exchange with the network).

[0159] The WTRU may determine the type of ML PDU session based on the type of application and / or properties (e.g., a property) of the application. For example, an application service data flow may have multiplexed traffic flows (e.g., some of which are more amenable to) configured for a non-integrated non- 3GPP access leg. The WTRU may determine to use an (e.g., a simplified) ATSSS PDU session if the service data flow for the application includes traffic of this type (e.g., multiplexed traffic flows). The traffic descriptor of the URSP rule may be extended to include a multiplexed traffic capability. For example, the multiplexed traffic capability may provide an indication of how to map multiplexed traffic to a PDU session. In examples, the multiplexed traffic capability may be single, implying that the application service data flow is from a single traffic flow (e.g., no multiplexed traffic). In examples, the multiplexed traffic capability may be multiple, implying that the application service data flow includes (e.g., is made up of) multiple traffic flows. In examples, the multiplexed traffic capability may be multiple - w / o delay sensitive, indicating (e.g., implying) that the application service data flow includes (e.g., is made up of) multiple traffic flows (e.g., but that none of the traffic flows are delay sensitive). In examples, the multiplexed traffic capability may be multiple with delay-sensitive, indicating (e.g., implying) that the application service data flow includes (e.g.,is made up of) multiple traffic flows and / or that a traffic flow (e.g., some of the traffic flows) are delaysensitive. If a traffic flow (e.g., some of the traffic flows) is delay-sensitive, these flows may use the nonintegrated non-3GPP access. As a result, the application traffic may be mapped to an (e.g., simplified) ATSSS PDU session.

[0160] The WTRU may determine the type of ML PDU session based on existing WTRU connectivity (e.g., the WTRU may already be using two access legs for other service data flows). The WTRU may decide to piggyback the ML PDU session on existing access leg(s). For example, if a WTRU (e.g., already) has a first service data flow over a 3GPP access and a second service data flow over a non-3GPP untrusted access, the WTRU may decide to use an MA PDU session based on ATSSS.

[0161] The WTRU may determine the type of ML PDU session based on the type of PLMN. For example, the WTRU may decide to use a MA PDU session with (e.g., or based on) ATSSS if connected to a HPLMN or equivalent HPLMN, and / or to use an (e.g., simplified) ATSSS PDU session otherwise. The WTRU may provide an indication to base a ML PDU session type selection on a PLMN type. This indication may be (pre-)configured in the WTRU or signaled to the WTRU in the URSP rule within a new route selection description component (e.g., ML PDU session type restriction).

[0162] The WTRU may determine the type of ML PDU session based on a PLMN ID. The WTRU may be provided a list of PLMN IDs for which it may use a (e.g., specific) type of ML PDU session. The WTRU may (e.g., alternatively) be provided a list of PLMN IDs for which a (e.g., certain) ML PDU session type(s) is not allowed (e.g., are not allowed). The WTRU may receive the list of PLMN IDs from the network (e.g., in new URSP rules) or through (pre-)configuration (e.g., the WTRU may be configured with a list of PLMN IDs).

[0163] The WTRU may determine the type of ML PDU session based on supported non-3GPP (e.g., based on whether a non-3GPP is supported by the WTRU). The WTRU may decide to use a first (e.g., one) PDU session type over a second (e.g., another) PDU session type, based on the non-3GPP supported by the WTRU. For example, the WTRU may decide to use a MA PDU session with (e.g., or based on) DualSteer if the WTRU supports (e.g., only supports) 802.11 n.

[0164] In a fourth ML PDU session type determination procedure, the WTRU may receive an indication that an application may use an ML PDU session, but the WTRU may prefer (e.g., determine) to have the network determine which type of ML PDU session. The WTRU may receive the indication in a URSP rule. The WTRU may send a request to the network, requesting the network to determine the ML PDU session type. The request may be sent in a NAS message (e.g., UL NAS transport, PDU session establishment request, and / or the like). The network may select (e.g., the type of ML PDU session) based on preference and / or based on connectivity to a non-3GPP access node.

[0165] In a fifth ML PDU session type determination procedure, the WTRU may determine to use an MP PDU session based on the WLANSP rules provided to the WTRU. For example, if the WLANSP rules indicate that the WLANs support non-integrated non-3GPP access, the WTRU may determine to use an MA PDU session based on an (e.g., simplified) ATSSS PDU session.

[0166] A WTRU may send a PDU session establishment request message over a 3GPP leg. After selecting the ML PDU session type, the WTRU may try to establish the ML PDU session. The WTRU may send a PDU session establishment request message over the 3GPP leg. This message may include an ML PDU session IE. This IE may include at least one of: a selected ML PDU session type, an indication to the network to choose the ML PDU session type, or a condition(s) at the WTRU.

[0167] A PDU session establishment request message sent over the 3GPP leg (e.g., by the WTRU) may include a selected ML PDU session type (e.g., one of the ML PDU session types).

[0168] A PDU session establishment request message sent over the 3GPP leg (e.g., by the WTRU) may include an indication to the network to choose the ML PDU session type. For example, the WTRU may decide to use an ML PDU session, but it would like the network to decide which type (e.g., the WTRU may determine to request that the network determine an ML PDU session type).

[0169] A PDU session establishment request message sent over the 3GPP leg (e.g., by the WTRU) may include condition(s) at the WTRU. The WTRU may provide information (e.g., to the network) about condition(s) at the WTRU. For example, this may include battery status, whether the WTRU is mains powered, and whether the WTRU supports non-3GPP (e.g., access) support (e.g., versions of 802.11 supported by a WTRU).

[0170] A WTRU may receive a PDU session establishment accept message. For example, the following description assumes that the WTRU or network (e.g., SMF) may have selected an (e.g., simplified) ATSSS PDU session (e.g., as described with reference to 2 and / or 3 of FIGS. 7A-B). One or more (e.g., other) session types may be selected and / or applied (e.g., as described herein).

[0171] After the SMF has determined the ML configuration, the SMF may provide an ML configuration rules IE to the WTRU and / or the N4 rules to the UPF. As part of this IE, the SMF may provide the WTRU at least one of: the IP address of the node hosting the ATSSS proxy functionality; a list of valid or preferred non-integrated non-3GPP access networks and / or nodes; an indication that the WTRU may use the WLANSP rules for selecting the non-3GPP access network; preferred characteristics of the non-3GPP access network and / or node; an indication whether the connection to the node hosting the ATSSS proxy may need to be secured (e.g., through an IP Sec tunnel); an indication whether the connection to the node hosting the ATSSS proxy requests (e.g., requires) a GRE tunnel; an indication whether the connection to the node hosting the ATSSS proxy requests (e.g., requires) a QUID tunnel; or new steering modeconfiguration parameter(s) and / or measurement configuration parameter(s) related to the (e.g., simplified) ATSSS PDU session (e.g., the selected session type).

[0172] The SMF may provide the WTRU with a list of valid and / or preferred non-integrated non-3GPP access networks and / or nodes. The network may know the non-3GPP access networks and / or nodes that are near the vicinity of the WTRU. For example, the network may store this information based on a (e.g., prior simplified) ATSSS PDU session(s). The list may be in the form of SSIDs. For secured non-3GPP access networks and / or nodes, the network may (e.g., additionally) provide security information to the WTRU (e.g., if known). The information per non-3GPP access network and / or node may include validity restrictions. For example, the restrictions may be with respect to a time or a location. For example, a (e.g., certain) non-3GPP access networks and / or nodes may be used during a time of day (e.g., for certain times of the day). For example, a (e.g., certain) non-3GPP access networks and / or nodes may (e.g., may only) be used if / when the 3GPP access leg is over a (e.g., certain) RAN node(s) and / or if / when the WTRU is in a (e.g., certain) tracking area. For example, (e.g., certain) non-3GPP access networks and / or nodes may (e.g., may only) be used if / when the WTRU is registered over a (e.g., certain) PLMN(s). The non-3GPP access networks may (e.g., also) have an associated priority.

[0173] The SMF may provide the WTRU with preferred characteristic(s) of the non-3GPP access network and / or node. A first characteristic may include the quality of the non-3GPP access network and / or node. For example, for a WTRU to select a non-3GPP access network, the non-3GPP access network may support at least 802.11 n. A second characteristic may be related to whether the non-3GPP access is public or private. For example, for a WTRU to select a non-3GPP access network, the non-3GPP access network may not be a public hotspot.

[0174] A WTRU may send a PDU session modification request message to an SMF. Once the WTRU has selected the non-3GPP access network and / or node, it may connect to the selected access network and / or node. The WTRU may be assigned an IP address over the access network.

[0175] The WTRU may inform the network about the non-3GPP access network selection, for example, via a PDU session modification request message. The message may include a non-3GPP access IE. The contents of this IE (e.g., a non-3GPP access IE) may include at least one of the IP address of the WTRU (e.g., the IP address the WTRU uses over the non-3GPP access network), an identifier of the non-3GPP access network (e.g., the SSID of a WLAN network), characteristic(s) of the selected non-3GPP access network and / or node, quality of the non-3GPP access, or an access token.

[0176] The WTRU may inform the network about (e.g., a non-3GPP access IE may include an indication associated with) characteristic(s) of the selected non-3GPP access network and / or node. A (e.g., first) characteristic(s) may include the type of the non-3GPP access network and / or node. For example, whetherthe non-3GPP access network is an 802.11ac network. A (e.g., second) characteristic may be related to whether the non-3GPP access is public or private.

[0177] The WTRU may inform the network about the (e.g., a non-3GPP access IE may include an indication associated with the) quality of the non-3GPP access. For example, the WTRU may know about (e.g., obtain or be configured with information regarding) the delay over the non-3GPP access, the loss over the non-3GPP access, the load over the non-3GPP access, and / or the like. This information may be provided to the network to (e.g., help) configure the ML PDU session steering modes.

[0178] The WTRU may inform the network about (e.g., a non-3GPP access IE and / or the like, may include an indication associated with) an access token. The WTRU may include the access token in PDUs over the non-3GPP access leg. The access token may be used by the node hosting the ATSSS proxy (e.g., to determine whether to accept the incoming PDU from the WTRU or to discard this PDU).

[0179] The WTRU may (e.g., alternatively or additionally) use the user plane connection to the UPF over the 3GPP leg to send a message to the UPF, including the non-3GPP access IE. For example, the IE may be sent via a PMF message.

[0180] A ML PDU session may be updated. For example, based on the contents of the received non- 3GPP access IE, the SMF may update the ML configuration rules to the WTRU and the N4 rules to the UPF. The SMF may (e.g., also) provide at least one of the following to the node hosting the ATSSS proxy: the IP address of the WTRU over the non-3GPP access leg or an access token. The access token and the IP address may be used in combination to further limit access to the node hosting the ATSSS proxy.

[0181] The SMF may provide an IP address of the WTRU over the non-3GPP access leg. The ATSSS proxy may use this information for (e.g., any) downlink traffic that is to be sent to the WTRU over the non- 3GPP access leg. The ATSSS proxy may (e.g., also) use this information for access control. For example, the node hosting the ATSSS proxy may maintain an access control list (e.g., including these IP addresses), and it (e.g., the node hosting the ATSSS proxy) may (e.g., may only) process PDUs from WTRUs with these IP addresses. If the WTRU and / or the node hosting the ATSSS proxy request (e.g., require) a tunnel over the non-3GPP access, then the access control list may (e.g., alternatively) be used to limit the IP address(es) that the node hosting the ATSSS proxy will accept a tunnel establishment request(s) from.

[0182] The SMF may (e.g., also) provide an access token. The (e.g., access) token may be used for access control to the node hosting the ATSSS proxy. For example, the node hosting the ATSSS proxy may maintain an access control list (e.g., list of access token(s)), and it may (e.g., may only) process PDUs from PDUs including the access token (e.g., containing this token). If the WTRU and / or node hosting the ATSSS proxy requests (e.g., require) a tunnel over the non-3GPP access, then the access control list may (e.g.,alternatively) be used to process (e.g., only process) tunnel establishment requests (e.g., if incoming PDUs have an access token that is on the access control list).

[0183] A WTRU may register over a non-3GPP access leg. In examples, the WTRU may (e.g., always) be requested (e.g., required) to register over the non-3GPP access leg. In examples, the network may request control (e.g., want to control) if a WTRU is requested (e.g., required) to register over the non-3GPP access leg.

[0184] If registration is requested (e.g., required) over the non-3GPP access (e.g., then in a first option), the WTRU may send the registration message over the user plane of the 3GPP access leg. One or more of the following (e.g., additional) operations may be requested (e.g., required to enable this first option).

[0185] With reference to FIG. 7A, at 5, the SMF may provide an indication to the WTRU that registration is requested (e.g., required) over the non-3GPP access leg. This may be included (e.g., an indication to the WTRU that registration is requested over the non-3GPP access leg) in the ML configuration rules IE. The network (e.g., SMF) may (e.g., additionally) provide a registration IP address associated with the registration message. The WTRU may send the registration message to this registration IP address.

[0186] With reference to FIG. 7B, if / when (e.g., after) the WTRU selects a non-3GPP access node at 6, the WTRU may (e.g., optionally) generate a registration request message (e.g., at 6a (not shown)). The request may be sent over the user plane to the UPF. The UPF may determine that this is a registration request message. The UPF may make this determination based on the destination address set to the registration IP address. A (e.g., new) PMF message may (e.g., alternatively) be defined that allows the WTRU to send the registration request message to the UPF. The UPF may forward the registration request message to the AMF (e.g., that is associated with the WTRU over the 3GPP access).

[0187] If registration is requested (e.g., required) over the non-3GPP access, the WTRU may (e.g., in a second option) send the registration message over the control plane of the 3GPP access leg. In order to enable this option, one or more of the following operations may be performed (e.g., required).

[0188] With reference to FIG. 7A, at 5, the SMF may provide an indication to the WTRU that registration is requested (e.g., required) over the non-3GPP access leg (e.g., to enable sending the registration message over the control plane of the 3GPP access leg). This may be included in the ML configuration rules IE.

[0189] With reference to FIG. 7B, if / when (e.g. after) the WTRU selects a non-3GPP access node at 6, the WTRU may generate a (e.g., new) non-integrated registration request message (e.g., at 6a (not shown)). The request (e.g., message) may be sent over the control plane to the AMF. The (e.g., new) message may indicate that it is (e.g., the message is) for the non-integrated non-3GPP access leg.

[0190] Although features and elements described above are described in particular combinations, each feature or element may be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements.

[0191] Although the implementations described herein may consider 3GPP specific protocols, it is understood that the implementations described herein are not restricted to this scenario and may be applicable to other wireless systems. For example, although the solutions described herein consider LTE, LTE-A, New Radio (NR) or 5G specific protocols, it is understood that the solutions described herein are not restricted to this scenario and are applicable to other wireless systems as well.

[0192] The processes described above may be implemented in a computer program, software, and / or firmware incorporated in a computer-readable medium for execution by a computer and / or processor. Examples of computer-readable media include, but are not limited to, electronic signals (transmitted over wired and / or wireless connections) and / or computer-readable storage media. Examples of computer- readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as, but not limited to, internal hard disks and removable disks, magneto-optical media, and / or optical media such as compact disc (CD)-ROM disks, and / or digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, terminal, base station, RNC, and / or any host computer.

Claims

CLAIMS1. A wireless transmit / receive unit (WTRU) comprising: a processor configured to: send a protocol data unit (PDU) session establishment request message, wherein the PDU session establishment request message comprises an indication of a PDU session type; receive a PDU session establishment response message, wherein the PDU session establishment response message indicates a multi-leg (ML) configuration and an access traffic steering, switching, and splitting (ATSSS) rule, wherein the ML configuration comprises an internet protocol (IP) address associated with an ATSSS proxy; based on the indication of the ML configuration and the ATSSS rule, select a non-3GPP access node; and direct traffic to the non-3GPP access node based on the ATSSS rule.

2. The WTRU of claim 1, wherein the PDU session type is a simplified ATSSS PDU session, and wherein the simplified ATSSS PDU session is selected based on UE route selection policy (URSP) rules.

3. The WTRU of claim 1 or 2, wherein the processor is further configured to: send a PDU session modification request message comprising an indication of an IP address associated with the WTRU, the non-3GPP access node, and an access token.

4. The WTRU of any one of claims 1-3, wherein the ATSSS rule comprises at least one of splitting, steering, switching, or duplicating the traffic.

5. The WTRU of any one of claims 1-4, wherein the processor is further configured to: send a PDU session modification request message comprising an ATSSS information element (IE) indicating whether a non-3GPP leg associated with the non-3GPP access node is secured.

6. The WTRU of any one of claims 1-5, wherein the processor is further configured to select the PDU session type based on a PDU session policy.

7. The WTRU of any one of claim 1-6, wherein the processor is further configured to select the PDU session type based on wireless local area network selection policy (WLANSP) rules, wherein the WLANSP rules indicate a wireless local area network (WLAN) non-3GPP access node, and wherein the selected non-3GPP access node is the WLAN non-3GPP access node.

8. The WTRU of any one of claims 1-7, wherein the processor is further configured to select the PDU session type based on an indication of a public land mobile network (PLMN) type or a PLMN ID.

9. The WTRU of any one of claims 1-8, wherein the PDU session establishment response message further comprises an indication to secure the traffic directed to the non-3GPP access node, wherein the indication indicates at least one of an internet protocol security (IP Sec) tunnel, a generic routing encapsulation (GRE) tunnel, or a QUID tunnel.

10. A method comprising: sending a protocol data unit (PDU) session establishment request message, wherein the PDU session establishment request message comprises an indication of a PDU session type; receiving a PDU session establishment response message, wherein the PDU session establishment response message indicates a multi-leg (ML) configuration and an access traffic steering, switching, and splitting (ATSSS) rule, wherein the ML configuration comprises an internet protocol (IP) address associated with an ATSSS proxy; based on the indication of the ML configuration and the ATSSS rule, selecting a non-3GPP access node; and directing traffic to the non-3GPP access node based on the ATSSS rule.11 . The method of claim 10, wherein the PDU session type is a simplified ATSSS PDU session, and wherein the simplified ATSSS PDU session is selected based on UE route selection policy (URSP) rules.

12. The method of claim 10 or 11 , wherein the method further comprises: sending a PDU session modification request message comprising an indication of an IP address associated with a WTRU, the non-3GPP access node, and an access token.

13. The method of any one of claims 10-12, wherein the ATSSS rule comprises at least one of splitting, steering, switching, or duplicating the traffic.

14. The method of any one of claims 10-13, wherein the method further comprises: sending a PDU session modification request message comprising an ATSSS information element (IE) indicating whether a non-3GPP leg associated with the non-3GPP access node is secured.

15. The method of any one of claims 10-14, wherein the method further comprises to selecting the PDU session type based on a PDU session policy.

16. The method of any one of claim 10-15, wherein the method further comprises selecting the PDU session type based on wireless local area network selection policy (WLANSP) rules, wherein the WLANSP rules indicate a wireless local area network (WLAN) non-3GPP access node, and wherein the selected non-3GPP access node is the WLAN non-3GPP access node.

17. A network node comprising: a processor configured to: receive, from a WTRU, a protocol data unit (PDU) session establishment request message, wherein the PDU session establishment request message comprises an indication of a PDU session type; send a PDU session establishment response message, wherein the PDU session establishment response message indicates a multi-leg (ML) configuration and an access traffic steering, switching, and splitting (ATSSS) rule, wherein the ML configuration comprises an internet protocol (IP) address associated with an ATSSS proxy; receive a PDU session modification request message comprising an indication of an IP address associated with a WTRU, a non-3GPP access node, and an access token; based on the received PDU session modification request message, determine an updated ML configuration; and send the updated ML configuration to the WTRU .

18. The network node of claim 17, wherein the PDU session type is a simplified ATSSS PDU session.

19. The network node of claim 17 or 18, wherein the ATSSS rule comprises at least one of splitting, steering, switching, or duplicating traffic, and wherein the PDU session establishment response message further comprises an indication to secure the traffic directed to the non-3GPP access node, wherein the indication indicates at least one of an internet protocol security (IP Sec) tunnel, or a generic routing encapsulation (GRE) tunnel, or QUID tunnel.

20. The network node of any one of claims 17-19, wherein the PDU session modification request message comprises an ATSSS information element (IE) indicating whether a non-3GPP leg associated with the non- 3GPP access node is secured.

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