WO2025240213A1 - Methods, architectures, apparatuses and systems for enabling synchronized access traffic steering, switching, splitting - Google Patents

Abstract

Procedures, methods, architectures, apparatuses, systems, devices, and computer program products for establishing a multi-access (MA) protocol data unit (PDU) session between a wireless transmit/receive unit (WTRU) node and a user plane function (UPF) node, includes determining at a first node (e.g., WTRU or UPF) of the nodes that it is a primary decision maker (PDM) in the MA PDU session. The PDM then collects data related to at least one performance measurement, selects an access for both uplink (UL) traffic and downlink (DL) traffic based, at least in part, on the at least one performance measurement, configures steering or switching for each of the UL traffic and the DL traffic using the selected access, and steers or switches one of the UL traffic (e.g., when the PDM is the WTRU) and the DL traffic (e.g., when the PDM is the UPF) using the selected access for the MA PDU session.

Description

METHODS, ARCHITECTURES, APPARATUSES AND SYSTEMS FOR ENABLING SYNCHRONIZED ACCESS TRAFFIC STEERING, SWITCHING, SPLITTING

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63/648,577, filed in the U.S. Patent and Trademark Office on May 16, 2024, which is hereby incorporated by reference herein in its entirety.

BACKGROUND

[0002] The present disclosure is generally directed to the fields of communications, software and encoding, including, for example, to methods, architectures, apparatuses, systems related to the selection of the uplink (UL) and downlink (DL) access in DualSteer or Access Traffic Steering, Switching, Splitting (ATSSS) capable devices.

SUMMARY

[0003] In certain representative embodiments, a method or procedure, and related apparatuses for establishing a multi-access (MA) protocol data unit (PDU) session between a wireless transmit/receive unit (WTRU) and a user plane function (UPF) include determining at a node (e.g., WTRU and UPF) that the node is a primary decision maker (PDM) in the established MA PDU session. The method further includes collecting, by the PDM, data related to performance measurements, selecting, by the PDM, an access for both UL traffic and DL traffic based on one or more of the collected performance measurements, configuring the steering or switching, by the PDM, for each of the UL traffic and DL traffic using the selected access for the MA PDU session, and performing the steering or switching of one of the UL traffic and DL traffic using the selected access for the MA PDU session after being configured. For example, when the PDM is the WTRU, the WTRU steers or switches the UL traffic using the selected access. When the PDM is the UPF, the UPF performs the steering or switching of the DL traffic using the selected access.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] A more detailed understanding may be had from the detailed description below, given by way of example in conjunction with drawings appended hereto. Figures in such drawings, like the detailed description, are examples. As such, the Figures (FIGs.) and the detailed description are not to be considered limiting, and other equally effective examples are possible and likely. Furthermore, like reference numerals ("ref.") in the FIGs. indicate like elements, and wherein: [0005] FIG. 1 A is a system diagram illustrating an example communications system; [0006] FIG. IB is a system diagram illustrating an example WTRU that may be used within the communications system illustrated in FIG. 1 A;

[0007] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A;

[0008] FIG. ID is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1 A;

[0009] FIG. 2 is a block diagram illustrating an example system with a WTRU that may be used within the communications system illustrated in FIG. 1 A;

[0010] FIG. 3 is a procedure for steering and switching of traffic using Synchronized ATSSS that may be implemented using the communications system illustrated in FIG. 1 A;

[0011] FIG. 4 is an example subprocess of the procedure illustrated in FIG. 3 for steering and switching of traffic using Synchronized ATSSS that may be implemented using the communications system illustrated in FIG. 1 A;

[0012] FIG. 5 is a flowchart of an illustrative process, performed by a WTRU, for establishing an MA PDU session between the WTRU and the UPF, each of which may be implemented in the block diagram of the system in FIG. 2;

[0013] FIG. 6 is a flowchart of an illustrative process, performed by a UPF, for establishing a MA PDU session between the WTRU and the UPF, each of which may be implemented in the block diagram of the system in FIG. 2; and

[0014] FIG. 7 is a flowchart of an illustrative process, performed by a session management function (SMF), for establishing an MA PDU session between the WTRU and the UPF, each of which may be implemented in the block diagram of the system in FIG. 2.

DETAILED DESCRIPTION

[0015] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of embodiments and/or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components and circuits have not been described in detail, so as not to obscure the following description. Further, embodiments and examples not specifically described herein may be practiced in lieu of, or in combination with, the embodiments and other examples described, disclosed or otherwise provided explicitly, implicitly and/or inherently (collectively "provided") herein. Although various embodiments are described and/or claimed herein in which an apparatus, system, device, etc. and/or any element thereof carries out an operation, process, algorithm, function, etc. and/or any portion thereof, it is to be understood that any embodiments described and/or claimed herein assume that any apparatus, system, device, etc. and/or any element thereof is configured to carry out any operation, process, algorithm, function, etc. and/or any portion thereof.

[0016] Example Communications System

[0017] The methods, apparatuses and systems provided herein are well-suited for communications involving both wired and wireless networks. An overview of various types of wireless devices and infrastructure is provided with respect to FIGs. 1A-1D, where various elements of the network may utilize, perform, be arranged in accordance with and/or be adapted and/or configured for the methods, apparatuses and systems provided herein.

[0018] FIG. 1A is a system diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), singlecarrier FDMA (SC-FDMA), zero-tail (ZT) unique-word (UW) discreet Fourier transform (DFT) spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block- filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0019] As shown in FIG. 1A, the communications system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104/113, a core network (CN) 106/115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and/or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a "station" and/or a "STA", may be configured to transmit and/or receive wireless signals and may include (or be) a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi- Fi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. Any ofthe WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE.

[0020] The communications systems 100 may also include a base station 114a and/or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d, e.g., to facilitate access to one or more communication networks, such as the CN 106/115, the Internet 110, and/or the networks 112. By way of example, the base stations 114a, 114b may be any of a base transceiver station (BTS), a Node-B (NB), an eNode-B (eNB), a Home Node-B (HNB), a Home eNode-B (HeNB), a gNode-B (gNB), a NR Node-B (NR NB), a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and/or network elements.

[0021] 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 an embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each or any sector of the cell. For example, beamforming may be used to transmit and/or receive signals in desired spatial directions.

[0022] 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).

[0023] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104/113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).

[0024] 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).

[0025] 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).

[0026] 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).

[0027] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (Wi-Fi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 IX, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0028] The base station 114b in FIG. 1 A may be a wireless router, Home Node-B, Home eNode- B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish any of a small cell, picocell or femtocell. As shown in FIG. 1 A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106/115.

[0029] The RAN 104/113 may be in communication with the CN 106/115, which may be any type of network configured to provide voice, data, applications, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106/115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and/or perform high-level security functions, such as user authentication. Although not shown in FIG. 1 A, it will be appreciated that the RAN 104/113 and/or the CN 106/115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104/113 or a different RAT. For example, in addition to being connected to the RAN 104/113, which may be utilizing an NR radio technology, the CN 106/115 may also be in communication with another RAN (not shown) employing any of a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

[0030] The CN 106/115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and/or other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The 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 104/114 or a different RAT.

[0031] 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. [0032] FIG. IB is a system diagram illustrating an example WTRU 102. As shown in FIG. IB, the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive element 122, a speaker/mi crophone 124, a keypad 126, a display/touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and/or other elements/peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0033] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit/receive element 122. While FIG. IB depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together, e.g., in an electronic package or chip.

[0034] The transmit/receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in an embodiment, the transmit/receive element 122 may be an antenna configured to transmit and/or receive RF signals. In an embodiment, the transmit/receive element 122 may be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example. In an embodiment, the transmit/receive element 122 may be configured to transmit and/or receive both RF and light signals. It will be appreciated that the transmit/receive element 122 may be configured to transmit and/or receive any combination of wireless signals.

[0035] Although the transmit/receive element 122 is depicted in FIG. IB as a single element, the WTRU 102 may include any number of transmit/receive elements 122. For example, the WTRU 102 may employ MIMO technology. Thus, in an embodiment, the WTRU 102 may include two or more transmit/receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0036] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0037] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and/or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), readonly memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0038] The processor 118 may receive power from the power source 134, and may be configured to distribute and/or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0039] 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 location-determination method while remaining consistent with an embodiment.

[0040] The processor 118 may further be coupled to other elements/peripherals 138, which may include one or more software and/or hardware modules/units that provide additional features, functionality and/or wired or wireless connectivity. For example, the elements/peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (e.g., for photographs and/or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a virtual reality and/or augmented reality (VR/AR) device, an activity tracker, and the like. The elements/peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and/or a humidity sensor.

[0041] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the uplink (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and/or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the uplink (e.g., for transmission) or the downlink (e.g., for reception)).

[0042] FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0043] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.

[0044] Each of the eNode-Bs 160a, 160b, and 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink (UL) and/or downlink (DL), and the like. As shown in FIG. 1C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface. [0045] The CN 106 shown in FIG. 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any one of these elements may be owned and/or operated by an entity other than the CN operator. [0046] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an SI interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation/deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and/or WCDMA.

[0047] The SGW 164 may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via the SI interface. The SGW 164 may generally route and forward user data packets to/from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter-eNode-B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0048] 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.

[0049] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and/or wireless networks that are owned and/or operated by other service providers.

[0050] Although the WTRU is described in FIGs. 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network. [0051] In representative embodiments, the other network 112 may be a WLAN.

[0052] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a distribution system (DS) or another type of wired/wireless network that carries traffic into and/or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and/or referred to as peer-to-peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.1 le DLS or an 802.1 Iz tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an "ad-hoc" mode of communication.

[0053] When using the 802.1 lac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier sense multiple access with collision avoidance (CSMA/CA) may be implemented, for example in in 802.11 systems. For CSMA/CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed/detected and/or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0054] High throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadj acent 20 MHz channel to form a 40 MHz wide channel.

[0055] Very high throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz, and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 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 a medium access control (MAC) layer, entity, etc. [0056] Sub 1 GHz modes of operation are supported by 802.11af and 802.1 lah. The channel operating bandwidths, and carriers, are reduced in 802.1 laf and 802.1 lah relative to those used in

802.1 In, and 802.1 lac. 802.1 laf supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV white space (TVWS) spectrum, and 802.1 lah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment,

802.1 lah may support meter type control/machine-type communications (MTC), such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and/or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0057] WLAN systems, which may support multiple channels, and channel bandwidths, such as

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

[0058] In the United States, the available frequency bands, which may be used by 802.1 lah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.1 lah is 6 MHz to 26 MHz depending on the country code.

[0059] FIG. ID is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0060] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, 180c may implement MEMO technology. For example, gNBs 180a, 180b may utilize beamforming to transmit signals to and/or receive signals from the WTRUs 102a, 102b, 102c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and/or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and/or gNB 180c).

[0061] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, OFDM symbol spacing and/or OFDM subcarrier spacing may vary for different transmissions, different cells, and/or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., including a varying number of OFDM symbols and/or lasting varying lengths of absolute time).

[0062] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and/or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with/connect to gNBs 180a, 180b, 180c while also communicating with/connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate 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.

[0063] 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 UPFs 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, and the like. As shown in FIG. ID, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0064] The CN 115 shown in FIG. ID may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one SMF 183a, 183b, and at least one Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and/or operated by an entity other than the CN operator. [0065] 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, e.g., to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for MTC access, and/or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and/or non-3GPP access technologies such as Wi-Fi.

[0066] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an Nl 1 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, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0067] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, e.g., to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi- homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0068] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and/or wireless networks that are owned and/or operated by other service providers. In an embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0069] In view of FIGs. 1 A-1D, and the corresponding description of FIGs. 1 A-1D, one or more, or all, of the functions described herein with regard to any of: WTRUs 102a-d, base stations 114a- b, eNode-Bs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a- b, SMFs 183a-b, DNs 185a-b, and/or any other element(s)/device(s) described herein, may be performed by one or more emulation elements/devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and/or to simulate network and/or WTRU functions.

[0070] 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.

[0071] The one or more emulation devices may perform the one or more, including all, functions while not being implemented/deployed as part of a wired and/or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and/or a non-deployed (e.g., testing) wired and/or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and/or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and/or receive data.

[0072] ATSSS

[0073] WTRUs are capable of 3rd Generation Partnership Project (3GPP) access and non-3GPP access to network. This capability provides flexibility to the network operators in determining which type of access (e.g., 3GPP and non-3GPP) to use for a Service Data Flow (SDF). A MA PDU session allows UL and DL traffic of a SDF to be steered, switched, or split between accesses (e.g., 3GPP access and non-3GPP access). A MA PDU session may be defined as a PDU session whose traffic can be sent over 3 GPP access (e.g., NR, Non-Terrestrial NR, E-UTRA, and LTE), or over non-3GPP access (e.g., a trusted Wireless Local-Area Network (WLAN), an untrusted WLAN, and wireline), or over both accesses. Additionally, an MA PDU session may refer to two PDU sessions (e.g., a first PDU session and second PDU session), where each PDU sessions may transfer traffic of an SDF. In such embodiments, the first PDU session may transport traffic over a first access, and the second PDU session may transport traffic over a second access. Both accesses over which each PDU session transports traffic may be 3GPP accesses (e.g., NR, NonTerrestrial NR, E-UTRA, and LTE), or non-3GPP accesses (e.g., a trusted Wireless Local-Area Network (WLAN), an untrusted WLAN, and wireline). A MA PDU session may also be referred to as a DualSteer PDU session (i.e., when the two accesses are both 3GPP accesses).

[0074] When ATSSS is implemented, the decision to split, steer or switch traffic may generally be made independently by the WTRU for UL traffic of the SDF and by the UPF for DL traffic of the SDF. However, the present disclosure presented herein, which is related to ATSSS, including DualSteer, ensures that the UL and DL traffic to be sent over the same access (e.g., 3GPP access and non-3GPP access) by implementing UL/DL synchronization. The present disclosure also presents new steering modes based on, in part, energy or cost of services.

[0075] Synchronizing UL and DL steering and switching may result in saving energy and/or resources, by using less resources on the WTRU and in the network (e.g., a next generation Node- B (gNB)). In some embodiments, only one WTRU (e.g., one radio) may be active while the other WTRUs can be inactive. In some embodiments, the network resources are reduced in the gNB, where some common resources are allocated for UL and DL traffic flows, instead of using different gNBs for UL traffic and DL traffic, which may lead to performance and resource inefficiencies.

[0076] Synchronizing UL and DL steering and switching may also result in saving energy and/or resources by using a single WTRU instead of two WTRUs. For example, in some embodiments, when each WTRU of a Dual Steer device may be connected to a different Public Land Mobile Network (PLMN), different cells conditions may result to one WTRU having a higher energy usage than the other WTRU. In such embodiments, it may be more energy efficient to use a single WTRU (i.e., a single access in the context of a DualSteer device) for both UL and DL traffic.

[0077] Synchronizing UL and DL steering and switching may also result in simplifying the network stack on a DualSteer WTRU. When a network flow of an application is connected to a single WTRU for UL and DL traffic, steering and switching of the traffic may be implemented by connecting a network interface as viewed by the application (e.g., a network socket) with a network interface of the WTRU that is currently active. This simplification may also improve performance when mixing UL from a first WTRU and DL from a second WTRU, since with two WTRUs, a software component may be required to dynamically determine to which WTRU to send a PDU.

[0078] When using ATSSS mechanisms (e.g., in the context of DualSteer), the access selection for UL and DL traffic may not be the same in some cases. In a first example, when using the smallest delay steering mode, the WTRU may determine that a first access has the smallest delay for UL traffic, and the UPF may determine that a second access has the smallest delay for DL traffic. For example, this may occur when the RTT is similar for both accesses (e.g., 3GPP access and non-3GPP access), and RTT fluctuations on both accesses (e.g., 3GPP access and non-3GPP access) result in a variability in smallest delay measurements. This variability may be further accentuated by the fact that the measurement performed by the WTRU and the measurement performed by the UPF may be performed at different times. Additionally, in some embodiments, smallest delay steering mode may rely on RTT measurements, however some embodiments of the smallest delay steering mode may rely on a one-way delay measurement, which may result in measurements performed by the WTRU and the UPF to differ in some cases.

[0079] In a second example, when using a steering mode that considers energy usage, the energy consumption for the traffic over ATSSS and/or DualSteer may depend on, in part, a combination of accesses used by UL and DL traffic. For example, when DL traffic is using the first access, UL traffic may use the first access based on energy consumption, while if DL traffic is using the second access, it may be determined that it is more energy efficient for UL traffic to use second access. An independent access selection for UL traffic by the WTRU and DL traffic by UPF, respectively, may lead to an unstable system where, the DL access selection may change to adapt to UL selection, and simultaneously the UL access selection may change to adapt to the DL access selection.

[0080] The disclosure presented herein enables synchronizing the decision to steer/switch UL traffic and DL traffic to an access. This mechanism may be useful, for example, in the context of DualSteer with existing steering modes, and/or in the context of ATSSS with new steering modes. [0081] FIG. 2 shows a system 200 with a WTRU 202 which uses an MA PDU session 204 for UL and DL traffic of an SDF to be steered, switched or split between accesses using synchronized ATSSS. The present disclosure provides an architecture for synchronized ATSSS which may be performed by one of the WTRU and the UPF 206 of the MA PDU session 204. Whichever one of the WTRU 202 and the UPF 206 is performing synchronized ATSSS at a respective time may be defined as the PDM. The architecture provided may enable (1) traffic steering of a new data flow, where an access network may be selected for the new data flow and transfers the traffic of this data flow over the selected access network (e.g., one of 3GPP access 208 and non-3GPP access 210), (2) traffic switching, where an ongoing data flow can be moved from one access network (e.g., one of 3 GPP access 208 and non-3GPP access 210) to another access network (e.g., the other one of 3GPP access 208 and non-3GPP access 210) in a way that maintains the continuity of the data flow, and (3) traffic splitting, where the traffic of a data flow can be split across multiple access networks (e.g., 3GPP access 208 and non-3GPP access 210). In some embodiments, some PDUs of the data flow are transmitted via one access(e.g., one of 3GPP access 208 and non-3GPP access 210) and some other PDUs of the same data flow are transmitted via another access (e.g., the other one of 3GPP access 208 and non-3GPP access 210).

[0082] The steering functionality, which may be implemented in one or more of the ATSSS- capable WTRU 202 and in the UPF 206, may steer, switch, and/or split the MA PDU session traffic (e.g., PDUs of a SDF) across multiple accesses (e.g., 3GPP access 208 and non-3GPP access 210). Three steering functionalities are disclosed herein, including two high-layer steering functionalities, which operate above the IP layer, e.g., the Multipath Transmission Control Protocol (MPTCP) steering functionality that may apply to Transmission Control Protocol (TCP) traffic, and the Multipath Quick UDP Internet Connections (MPQUIC) steering functionality that may apply to UDP traffic, and a low-layer steering functionality, which may operate below the IP layer, e.g., the ATSSS Low-Layer functionality (ATSSS-LL) which may apply to Ethernet and IP traffic.

[0083] A steering mode may be used to determine how the traffic of a corresponding SDF should be distributed across accesses (e.g., 3GPP access 208 and non-3GPP access 210). In some embodiments, (e.g., only) one steering mode may be used for an SDF.

[0084] Active- standby steering mode may configure the PDM (e.g., one of the WTRU 202 and UPF 210) to steer traffic of a respective SDF on one access (e.g., an active access) when the active access is available, and may switch the traffic to the other access (e.g., a standby access) when the active access becomes unavailable. [0085] Smallest delay steering mode may configure the PDM (e.g., one of the WTRU 202 and UPF 206) to steer traffic of a respective SDF to an access (e.g., one of the 3 GPP access 208 and the non-3GPP access 210) that is determined to have the smallest Round-Trip Time (RTT). The RTT may be defined as a duration of time for a network request to go from a starting point to a destination and back again to the starting point. The PDM (e.g., one of the WTRU 202 and UPF 206) may be configured to measure an RTT for each access (e.g., 3GPP access 208 and non-3GPP access 210) in order to determine which access has the lowest RTT. In some embodiments, the smallest delay steering mode may (e.g., only) be used for a non-guaranteed bit rate (non-GBR) SDF.

[0086] Load balancing steering mode may configure the PDM (e.g., one of the WTRU 202 and the UPF 206) to split traffic of a respective SDF across both accesses (e.g., 3 GPP access 208 and non-3GPP access 210) according to a configurable load balancing percentage. For example, the configurable load balancing percentage may be set to 30%, and the PDM (e.g., one of the WTRU 202 and the UPF 206) may be configured to use the 3GPP access 208 for 30% of the PDUs of the SDF, and the non-3GPP access 210 for 70% of the PDUs of the SDF. In some embodiments, an autonomous load-balance indicator may be provided by the network 216, and the WTRU 202 may be configured to autonomously determine the load balancing percentage for traffic splitting. In some embodiments, the load balancing steering mode may (e.g., only) be used for a non-GBR SDF.

[0087] Priority based steering mode may configure the PDM (e.g., one of the WTRU 202 and the UPF 206) to steer (e.g., all) traffic of a respective SDF which matches a policy and charging control (PCC) rule to a high priority access, until the high priority access is determined to be congested. For example, when the PDM is WTRU 202, WTRU 202 steers (e.g., all) UL traffic of a respective SDF, and when the PDM is UPF 206, UPF 206 steers (e.g., all) DL traffic of a respective SDF. Once the high-priority access is determined to be congested, the PDM may be configured to steer traffic of the SDF to the low priority access, i.e., the traffic of the SDF may be split over the two accesses (e.g., 3GPP access 208 and non-3GPP access 210). In some embodiments, the priority based steering mode may (e.g., only) be used for a non-GBR SDF.

[0088] Redundant steering mode (RSM) may configure the PDM (e.g., one of the WTRU 202 and UPF 206) to duplicate traffic of a respective SDF over both access legs (e.g., 3GPP access 208 leg and non-3GPP access 210 leg) of the MA PDU session 204.

[0089] Additional configuration may be provided by the network 216 to modify the steering mode behavior on the PDM (e.g., one of the WTRU 202 and UPF 206). For example, a WTRU- assistance indicator may enable the WTRU 202 to determine how to distribute UL traffic of a SDF in some cases (e.g., when the WTRU 202 may be in low battery mode). In some embodiments, the network 216 may also provide a threshold value (e.g., an RTT threshold value or packet loss rate threshold value) to enable the PDM (e.g., one of the WTRU 202 and the UPF 206) to reduce usage on a respective access leg (e.g., one of 3GPP access 208 leg and non-3GPP access 210 leg) when a threshold value (e.g., an RTT threshold value or packet loss rate threshold value) is reached or exceeded on the respective access leg (e.g., one of the 3GPP access 208 and non-3GPP access 210). In some embodiments, for MPQUIC steering functionality, a configuration provided by the network 216 may enable transporting a UDP stream or datagram without reordering.

[0090] In some embodiments, a performance management functionality protocol (PMFP) may be used between a PDM node (e.g., one of the WTRU 202 and UPF 206) and a non-PDM node (e.g., the other one of the WTRU 202 and the UPF 206) to collect measurements (e.g., RTT, access availability report, packet loss rate) that are used, in part, for the steering/ switching mode decisions by the PDM. In some embodiments, one or more of the WTRU 202 and the UPF 206 includes a performance management functionality (PMF).

[0091] In some embodiments, the selection of a steering functionality and steering mode for a SDF in a MA PDU session 204 may be performed by an SMF 214, based on MA PDU session control information present in a PCC rule. In some embodiments, MA PDU session control information may include a steering mode and a steering functionality, as well as additional configuration parameters or data related to performance measurements.

[0092] DualSteer

[0093] Multi-access Steering, Switching, or Splitting (MASSS) and Dual Steer devices may allow traffic steering and/or switching between two 3GPP access networks (e.g., 3GPP access 208) connected to the same or different mobile networks (MNs). The 3GPP access networks (e.g., 3GPP access 208) may be of the same RAT or of different RATs (e.g., including terrestrial and non-terrestrial NR, E-UTRA). In some embodiments, a subscriber of a DualSteer device has two subscriptions/Subscription Permanent Identifiers (SUPIs), sharing one subscription profile from the same operator. In some embodiments, at any given respective point of time, all traffic of a single service (e.g., SDF) may be sent over a single access network, i.e., there may be no service data splitting. In some embodiments, DualSteer steering and switching functionality may be (e.g., only) allowed for Dual Steer devices, such as a single WTRU Dual Steer device, which may not support simultaneous data transmission over two access networks, and a dual-WTRU DualSteer that may include two separate WTRUs (e.g., WTRU 202) and supports simultaneous data transmission, i.e., of traffic for different services, over two access networks. Policy control of DualSteer may be enabled by enhanced PCC rules and may be communicated to the WTRU (e.g., WTRU 202) in enhanced ATSSS rules and to the UPF in enhanced multi-access rules (MAR). The enhanced rules (e.g., enhanced PCC rules, enhanced ATSSS rules, and enhanced MAR) may collectively be designated herein as “DualSteer rules”, or DS rules, and, may include existing multi-access information including application descriptors, IP and non-IP descriptors, steering functionality, steering mode, threshold values, and transport mode. The DS rules may include new values for information elements (IES) to enable additional cases. For example, the DS rules may enable two 3 GPP accesses (e.g., 3 GPP access 208) while, generally, the MARs enable one 3 GPP access 208 and one non-3GPP access 210.

[0094] A synchronized ATSSS (SynATSSS) feature is described herein to enable synchronizing the decision to steer/switch traffic to an access. When SynATSSS is used, a PDM node (e.g., one of a WTRU 202 and UPF 206) may determine the access to steer/switch traffic through for both UL and DL traffic. The term “UPF” (e.g., UPF 206) used herein, may be used to designate a PDU session anchor (PSA) UPF. The PDM may be WTRU 202 or UPF 206 of the MA PDU session 204. In some embodiments, the PDM role may be delegated to another node (e.g., the SMF 214 or another network function (NF)), which may be configured to collect information from the WTRU 202 and/or UPF 206, and make a steering/switching decision. For simplicity, the PDM may be described as the WTRU 202 or UPF 206 hereinafter. When SynATSSS is used, a non- PDM node may be any node that is not the PDM, (e.g., the WTRU 202 when UPF 206 is the PDM, and the UPF 206 when the WTRU 202 is the PDM). In some embodiments, when an NF is the PDM, each of the WTRU 202 and UPF 206 are non-PDM nodes.

[0095] The SynATSSS feature operation covers, at least, the following phases: (a) a network 216 that may determine to use SynATSSS, (e.g., possibly) based on SynATSSS capabilities (e.g., indication data that a node is capable of SynATSSS), (b) a communication system, either statically or dynamically, determines the PDM, and (c) during the lifetime of the MA PDU session 204, the PDM may collect information and may determine steering/switching decisions following one of multiple operational methods.

[0096] In some embodiments, the operational methods may include the following steps: (1) the PDM obtains data related to performance measurements for the access legs (e.g., 3 GPP access 208 or non-3GPP access 210) of the MA PDU session 204, (2) the PDM determines the steering/switching of UL and DL traffic, and (3) the PDM triggers the steering/switching of the UL and DL traffic.

[0097] SynATSSS Capabilities

[0098] In a first phase, a network (e.g., the SMF 214) selects a UPF 206 and determines to use SynATSSS, based on SynATSSS capabilities. The SynATSSS capability may indicate that a node (e.g., WTRU 202 or UPF 206) may be capable of performing the procedures described herein. A SynATSSS capability of a respective node may (e.g., additionally) include a PDM capability, which may indicate that the respective node may be capable of being assigned a role of: PDM only, non-PDM only, or that the node may be assigned either a PDM role or non-PDM role.

[0099] In some embodiments, the WTRU 202 may include a corresponding SynATSSS capability in a PDU session establishment or PDU session modification request message. In some embodiments, the SynATSSS capability may include a PDM capability in the PDU session establishment or PDU session modification message transmitted by the WTRU 202. Additionally, or alternatively, the SynATSSS capability of the WTRU 202 may be stored on the subscription profile of a subscription associated with the WTRU 202. The SMF 214 may obtain the SynATSSS capability of a WTRU 202 from the PDU session establishment or PDU session modification request, and/or from the WTRU subscription profile.

[0100] A network operator of a network 216 may configure the network 216 (e.g., in the SMF 214, the Network Repository Function (NRF) or the UPF 206) with a SynATSSS capability for the UPF 206. In some embodiments, the network operator may configure the network 216 with a SynATSSS that includes a PDM capability for the UPF 206. The SMF 214 may obtain the SynATSSS capability of the UPF 206 from any one of (a) a local configuration of the SMF 214, (b) the NRF, and (c) the UPF 206 over an N4 interface when setting up the basic N4 connection between SMF 214 and UPF 206. In some embodiments, depending on the SynATSSS capability of the WTRU 202, the SMF 214 may consider the SynATSSS capabilities when selecting a UPF 206 (e.g., the SMF 214 selects a UPF 206 that supports SynATSSS).

[0101] The SMF 214 may determine to use SynATSSS for a PDU session (e.g., MA PDU session 204) based on one or more factors, including (a) whether the PDU session is using DualSteer (e.g., based on DualSteer indication data in the PDU session establishment/modification request), (b) whether the steering mode requires SynATSSS (e.g., some steering modes when used with Dual Steer such as smallest delay, while other steering modes may always require SynATSSS such as a steering mode for energy consumption efficiency), (c) whether the steering mode supports SynATSSS (e.g., in some systems, smallest delay steering mode supports both SynATSSS and ATSSS, and the SMF 214 may use other factors to determine which to use, and in some systems, steering modes that support steering and switching but do not require splitting, may support SynATSSS), (d) whether a PCC rule includes SynATSSS indication data (e.g., in the MA PDU session control information of the PCC rule), and (e) whether the WTRU 202 and UPF 206 support SynATSSS (e.g., based on the SynATSSS capabilities of the WTRU 202 and of the UPF 206, respectively). [0102] In a first example, the SMF 214 may determine to use SynATSSS when using DualSteer with a smallest delay steering mode. In a second example, the SMF 214 may determine to use SynATSSS when the steering mode (e.g., an energy consumption efficiency related steering mode) may be known to require SynATSSS. In a third example, the SMF 214 may determine to use SynATSSS when the steering mode may be known to support SynATSSS, and when a PCC rule indicates to use SynATSSS for the PDU session (e.g., MA PDU session 204). The SMF 214 may be configured to (e.g., only) determine to use SynATSSS when each of the WTRU 202 and UPF 206 supports SynATSSS.

[0103] Determining the PDM

[0104] In a second phase, when SynATSSS is used, the network (e.g., the SMF 214) may determine the PDM (e.g., one of WTRU 202 and UPF 206) for the PDU session (e.g., MA PDU session 204). In some embodiments, the PDM may be statically determined for all PDU sessions (e.g., MA PDU session 204). In such embodiments, the PDM may be either the UPF 206 or the WTRU 202, and once the PDM determination is made no additional decision is performed for the second phase.

[0105] In some embodiments, the PDM may be dynamically determined for a PDU session (e.g., an MA PDU session 204). In such embodiments, the network (e.g., SMF 214) may decide which node, between the WTRU 202 and the UPF 206, will be the PDM for synchronized steering/switching. The network (e.g., SMF 214) then sends respective PDM indication data to each of the UPF 206 and the WTRU 202 (i.e., indicating “PDM” for one, and “non-PDM” for the other). In some embodiments, the PDM indication data may be a new IE, or a new value of an existing IE. For example, the ATSSS steering mode sent to WTRU 202 and UPF 206 may include a first value (i.e., “smallest delay at wtru”), which may indicate that the PDM may be the WTRU 202, or a second value (i.e., “smallest delay at upf ’), which may indicate that the PDM may be the UPF 206. In some embodiments, the PDM determination may be performed on one of a PDU session basis and a per-flow (e.g., SDF) basis. The PDM determination by the network (e.g., SMF 214) may be based on one or more factors.

[0106] For application flows that are expected to be downlink-heavy (e.g., video streaming from an application server (AS)), the UPF 206 may be preferred as PDM, as the selection of the DL traffic access will (e.g., likely) be most consequential on the application Quality of Experience (QoE). For applications flows that are expected to be uplink-heavy (e.g., video streaming from the WTRU 202), the WTRU 202 may be preferred as PDM, as the selection of the UL traffic access will likely be most consequential on the application QoE. [0107] In some embodiments, the node (e.g., WTRU 202, UPF 206, SMF 214 and NF) that will obtain the most accurate and/or most timely measurements (e.g., data related to performance measurement) needed for the steering mode operation may be preferred to be selected as the PDM. For example, if some energy efficiency measurements are initially available on the WTRU 202 (e.g., obtained from the network interface), then the WTRU 202 may be preferred to be selected as the PDM when an energy-related steering mode is used. In another example, if the energy efficiency measurements are obtained from an NF, then the NF may be preferred to be selected as the PDM, when an energy-related steering mode is used.

[0108] In some embodiments, the PDM selection may be determined, in part, by a WTRU policy, e.g., as part of UE Route Selection Policy (URSP) rules, ATSSS rules, or DS rules. Selecting the PDM based on the WTRU policy may enable the WTRU 202 to determine whether to act as the PDM for specific SDFs. Similarly, the PDM selection may be determined, in part, on rules received by the UPF 206 (e.g., as part of Multi-Access Rule) to determine whether the UPF 206 may act as the PDM for other specific SDFs. The PDM selection may be at least based on the PDM capabilities of each of the WTRU 202 and UPF 206.

[0109] Once the SMF 214 determines to use SynATSSS and (e.g., if applicable) which node is the PDM, the SMF 214 may be configured to provide SynATSSS indication data to each of the UPF 206 (e.g., in N4 MAR or DS rules) and the WTRU 202 (e.g., in ATSSS rules or DS rules), where the SynATSSS indication data indicates that SynATSSS may be used or is to be used. In some embodiments, each of the SynATSSS indication data may include a PDM indication data that indicates the role (e.g., PDM or non-PDM) of the recipient of the message containing the indication data (e.g., WTRU 202 or UPF 206).

[0110] In some implementations, the SMF 214 determines to use SynATSSS and provides SynATSSS indication data to each of the UPF 206 and the WTRU 202, where the SynATSSS indication data indicates that SynATSSS may be used or is to be used. Upon receiving the SynATSSS indication data, the WTRU 202 may be configured to perform the determination of its role (e.g., PDM or non-PDM), based on one or more of (a) the SynATSSS indication data, (b) characteristics of the traffic (e.g., UL traffic heavy or DL traffic heavy), and (c) the network operator’s policy (e.g., PDM indication data in a URSP rule). The WTRU 202 may then transmit a message (e.g., a PMFP message) to the UPF 206 to indicate the role of the WTRU 202 and/or the role of the UPF 206. The UPF 206 may determine its role based on the message received from the WTRU 202.

[0111] In cases where SynATSSS is not used, DualSteer capable devices use a mechanism based on, or similar to, legacy ATSSS, where the WTRU 202 and UPF 206 both operate their own steering mode independently from each other and decide independently over which access to steer or switch the application traffic (e.g., SDF). This mechanism may provide legacy accommodations for WTRUs (e.g., WTRU 202) that do not support SynATSSS. However, this mechanism may result in issues when UL traffic and DL traffic are sent over different accesses with DualSteer, as discussed hereinbefore. The network (e.g., SMF 214) may omit the SynATSSS indication data or set the SynATSSS indication data to a null value in messages sent to each of the UPF 206 and the WTRU 202 to enable this legacy mechanism.

[0112] Operational Method

[0113] Several operational methods may be used to drive the SynATSSS steering and switching decision. In a first operational method, the PDM (e.g., WTRU 202 or UPF 206) performs measurements related to UL traffic and/or DL traffic (e.g., by collecting RTT measurements and packet loss measurements) and may determine the steering/switching decision for each of the UL traffic and DL traffic. In some embodiments, the PDM (e.g., WTRU 202 or UPF 206) steers or switches a first traffic of the UL traffic and DL traffic, and configures the non-PDM to steer or switch a second traffic of the UL traffic and DL traffic. For example, when the WTRU 202 is the PDM, the WTRU 202 steers or switches UL traffic and configures the UPF 206 to steer or switch the DL traffic based on a selected network access leg. When the UPF 206 is the PDM, the UPF 206 steers or switches DL traffic and configured the WTRU 202 to steer or switch UL traffic based on a selected network access leg. In some embodiments, where the PDM is an NF (e.g., an Energy Efficiency Control Function), the PDM collects energy efficiency related measurements, and may determine the steering/switching decision for each of the UL traffic and DL traffic. In a second operational method, the PDM may perform measurements and receive measurement results from the non-PDM. For example, the WTRU 202 may use the PMFP to measure the RTT or packet loss and may (e.g., additionally) receive RTT or packet loss measurement reports from the UPF 206. In some embodiments, the PDM may determine the steering/switching decision for each of the UL traffic and DL traffic by using a combination of PDM measurement and non-PDM measurement reports.

[0114] Alternative operational methods may be used, such that the PDM may be configured to receive tentative steering/switching decisions from a non-PDM node. However, in some embodiments, the PDM may use a combination of all information available to the PDM to determine the steering/switching decision for each of the UL traffic and DL traffic. Another alternative operational method may be used, such that both WTRU 202 and UPF 206 act as PDM (e.g., similarly to the first operational method for both WTRU 202 and UPF 206). In such an alternative operational method, both WTRU 202 and UPF 206 obtain measurements, and one of the WTRU 202 or UPF 206 to first determine a steering/switching decision triggers the steering/ switching decision for both UL traffic and DL traffic.

[0115] Performance Measurements

[0116] The PDM (e.g., one of WTRU 202 and UPF 206) may be configured to obtain performance measurements during any one operational method. In some embodiments, the performance measurements include measurements obtained using PMFP that are (e.g., usually) used for MA PDU sessions (e.g., MA PDU session 204), such as RTT, packet loss rate, availability report, or new PMF measurements such as one-way delay. In some embodiments, the PDM (e.g., WTRU 202 or UPF 206) may be configured to send a PMFP message to request a PMFP procedure and obtain the measurement through the PMFP procedure. The performance measurements may also include measurements using a transport protocol, such as QUIC when using an MPQUIC steering functionality, or TCP when using an MPTCP steering functionality. In some embodiments, the PDM (e.g., WTRU 202 or UPF 206) collects measurements from an internal state of a transport protocol endpoint on the PDM. For example, the PDM may use the RTT estimation maintained by a QUIC protocol endpoint for congestion control. In some embodiments, the PDM may use other measurements, such as one-way delay by using transport protocol specific methods. In some embodiments, the performance measurements include measurements from a non-PDM node. The PDM (e.g., WTRU 202 or UPF 206) may obtain measurement reports from a non-PDM node (e.g., UPF 206 or WTRU 202). In such embodiments, the non-PDM node may be configured to prepare measurement reports based on information collected using a PMFP procedure or using a transport protocol (e.g., using a “Measurement Report” message). In some embodiments, the PDM sends a message to the non-PDM node to trigger a measurement (e.g., using a “Trigger Measurement” message, including a PMFP message type IE that identifies a type of measurement procedure to trigger) and/or a measurement report (e.g., using a “Measurement Report Request” message). The measurements reported by the non-PDM node may be any PMFP related measurements or transport protocol related measurements, as described hereinbefore. Other measurements may be obtained by the PDM by other means, such as obtaining measurements from an NF (e.g., an Energy Efficiency Control Function) through the AMF 212.

[0117] Steering/Switching Decision

[0118] The PDM may be configured to use performance information when determining the steering/switching decision. For example, for the first operational method, and when the smallest delay steering mode is used, the PDM may determine to steer/switch traffic to an access (e.g., 3GPP access 208 and non-3GPP access 210) with the lowest RTT or e.g., with the lowest UL delay or lowest DL delay. For the second operational method, and when the smallest delay steering mode is used, the PDM may determine to steer/switch traffic to an access (e.g., 3GPP access 208 and non-3GPP access 210) with the lowest average RTT. In some embodiments, each average RTT may be calculated by determining an average of a first RTT measured by the PDM and a second RTT measured by the non-PDM. In some other embodiments, the average RTT may be calculated by adding a one-way UL measurement by the WTRU 202 and a one-way DL measurement by the UPF. In some embodiments, the one-way UL delay and one-way DL delay may be associated with different weights when calculating the average RTT. For example, for UL-heavy traffic, the UL delay may have a larger weight in the average RTT calculation.

[0119] If both WTRUs (e.g., WTRU 202) of a DualSteer device are connected to different PLMNs (e.g., using different cells), the energy consumption may differ between the two WTRUs depending on radio conditions. In some embodiments, when the PDM obtains measurements related to energy efficiency, the PDM may determine to steer/switch traffic to the access (e.g., 3GPP access 208 or non-3GPP access 210) that has a highest energy efficiency.

[0120] When a steering mode is used with DualSteer, the steering mode using a combination of measurements including RTT, packet loss rate, access availability, energy efficiency and cost, the PDM may be configured to determine to steer/switch traffic to the access (e.g., 3GPP access 208 or non-3GPP access 210) with a highest rating, based on a rating function combining each of the measurement values.

[0121] T riggering the Steering/Switching of T raffic

[0122] Once the PDM (e.g., WTRU 202 or UPF 206) determines the decision to steer or switch traffic on a specific access (e.g., 3GPP access 208 or non-3GPP access 210), the PDM sends a SynATSSS steering/switching request message to the non-PDM (e.g., new PMFP message, or NAS message) to request steering/switching traffic to an access (e.g., 3GPP access 208 or non- 3GPP access 210) specified in the message. Upon reception of the SynATSSS steering/switching request, the non-PDM may steer or switch traffic to the specified access (e.g., 3GPP access 208 or non-3GPP access 210). The non-PDM may send a response message (e.g., over the previously used access, in the user plane after the last PDU sent over this access). Upon receiving the response message, the PDM may start sending PDUs on the new access (e.g., 3GPP access 208 or non- 3 GPP access 210).

[0123] In some systems, further actions may be taken to improve the synchronization. For example, the non-PDM may send a marker PDU on the previously used access, and the PDM may monitor the previous access for the marker PDU, which indicate the time where it may be safe to switch to the new access for reception.

[0124] Synchronized ATSSS Steering and Switching Procedure [0125] FIG. 3 illustrates an exemplary process 300 for the steering and switching of a traffic flow (e.g., SDF) using SynATSSS.

[0126] At 302, the WTRU application (e.g., of WTRU 202) initiates the establishment of an application flow with a remote peer 301.

[0127] At 304, the WTRU 202 selects a URSP rule for the established application flow. In some embodiments, the selected URSP rule may include indication data that SynATSSS may or is to be used. In some other embodiments (not pictured in FIG. 3), instead of performing 302 and 304, the network may be configured to trigger the PDU session establishment or modification at 306, for example, based on a message from an AF or other Core Network (CN) NF.

[0128] At 306, the WTRU 202 sends a (e.g., multi-access) PDU session establishment or modification request, which may include a SynATSSS capability or indication data. In some embodiments, the WTRU 202 sends the (e.g., MA) PDU session establishment or modification request to the SMF 214.

[0129] At 308, the SMF 214 determines to use SynATSSS for the (e.g., MA) PDU session. In some embodiments, the SMF 214 may (e.g., dynamically) determine the PDM. The SMF 214 is configured to select a UPF 206 that supports SynATSSS, based on the SynATSSS capability of the UPF 206. For example, the SynATSSS capability of the UPF 206 may be configured in SMF 214 by the network operator, provided by UPF 206 over the N4 interface, or configured in NRF by the operator.

[0130] At 310, the SMF 214 sends an (e.g., N4) message to the UPF 206, the message including SynATSSS indication data. In some embodiments, the SynATSSS indication data may include PDM indication data.

[0131] At 312, the UPF 206 may then determine whether the UPF 206 is the PDM or a non-PDM node, based on the indication data from SMF 214 or based on a network operator’s configuration. In some embodiments, the UPF 206 may configure itself to act as a PDM or a non-PDM node based on the SynATSSS indication data and on the PDM indication data.

[0132] At 314, the UPF 206 then sends an (e.g., N4) response message to the SMF 214, to indicate the success of the operation.

[0133] At 316, the SMF 214 sends a PDU session establishment/modification response message to the WTRU 202. The PDU session establishment/modification response message may include a SynATSSS indication data, which may include a PDM indication data. The response message may also include (e.g., usual) IES, such as the steering functionality (e.g., MPTPC, MPQUIC) and steering mode. [0134] At 318, the WTRU 202 determines whether the WTRU 202 is the PDM or a non-PDM node, based on the SynATSSS indication data of the response message from SMF 214 or based on a network operator’s configuration. In some embodiments, the WTRU 202 may configure itself to act as a PDM or non-PDM node based on the SynATSSS indication data and on the PDM indication data. At this point, the (e.g., MA) PDU session is established or modified, between the WTRU 202 and the UPF 206, over the 3 GPP access.

[0135] At 320, the PDM collects measurements. In some embodiments, the PDM collects measurements based on measurement reports received from a non-PDM node. In some embodiments, the measurements may include performance measurements obtained using PMFP, such as RTT, packet loss rate, availability report, or one-way delay. In some embodiments, the PDM (e.g., WTRU 202 or UPF 206) may be configured to send a PMFP message to request a PMFP procedure and obtain the measurement through the PMFP procedure.

[0136] At 322, the PDM determines to perform a steering decision and triggers the traffic steering with the non-PDM. In some embodiments, the PDM may determine the steering decision based on, in part, one or more of the steering mode and the measurements collected at 320.

[0137] At 324 and 326, the application traffic (e.g., SDF) is transported over the first access leg (e.g., one of the 3GPP access leg and the non-3GPP access leg) of the DualSteer PDU session.

[0138] At 328, the PDM collects measurements as described hereinbefore, similarly as at 320.

[0139] At 330, the PDM determines to perform a switching decision and triggers the traffic switching with the non-PDM, similarly to determining the steering decision at 322. In some embodiments, the PDM may determine the switching decision based on, in part, one or more of the steering mode and the measurements collected at 328.

[0140] At 332 and 334, the application traffic is transported over the second access leg (e.g., the one of the 3GPP access leg and the non-3GPP access leg not used at 324 and 326) of the DualSteer PDU session.

[0141] Decision

[0142] FIG. 4 describes an exemplary subprocess 400 for synchronized steering or switching, which may be implemented at 322 and 330 of process 300 of FIG. 3. The referenced WTRU, UPF, 3GPP access, and non-3GPP access may be implemented as WTRU 202, UPF 206, 3GPP access 208, and non-3GPP access 210, respectively.

[0143] At 406, the PDM 402 (e.g., one of a WTRU and UPF) determines to steer or switch the traffic to use an access (e.g., 3 GPP access or non-3GPP access).

[0144] At 408, the PDM 402 (e.g., one of a WTRU and UPF) sends a SynATSSS steering/ switching request message to the non-PDM 404 (e.g., the other one of a WTRU and UPF, which is not the PDM 402), such that the SynATSSS steering/switching request message may include an identification of the access determined at 406.

[0145] At 410 and 412, the non-PDM 404 starts sending the PDUs of the PDU session over the identified access and sends a SynATSSS steering/switching response message to the PDM 402 to provide an indication that the operation performed successfully.

[0146] At 414, the PDM 402 starts sending the PDUs of the PDU session over the identified access (e.g., one of 3GPP access and non-3GPP access).

[0147] FIG. 5 is a flowchart of an illustrative process 500, performed by WTRU (e.g., WTRU 202), for establishing a MA PDU session (e.g., MA PDU session 204) between the WTRU and the UPF (e.g., UPF 206), each of which may be implemented in the system 200 in FIG. 2.

[0148] At 502, the WTRU determines that the WTRU is the PDM in a MA PDU session between the WTRU and UPF.

[0149] At 504, the WTRU collects data related to one or more performance measurements associated with one or more access (e.g., 3GPP access or non-3GPP access) of the MA PDU session.

[0150] At 506, the WTRU selects an access of the one or more access (e.g., 3GPP access or non- 3 GPP access) for both UL traffic and DL traffic based at least in part on the one or more performance measurements collected at 504.

[0151] At 508, the WTRU configures steering or switching for each of the UL traffic and the DL traffic using the selected access for the MA PDU session. The WTRU is configured to steer or switch the UL traffic using the selected access for the MA PDU session, and the UPF is configured, by the WTRU, to steer or switch the DL traffic using the selected access for the MA PDU session. In some implementations, the WTRU transmits, to the UPF, an indication to steer or switch DL traffic using the selected access

[0152] At 510, the WTRU performs the steering or the switching for the UL traffic using the selected access for the MA PDU session after being configured at 508.

[0153] FIG. 6 is a flowchart of an illustrative process, performed by a UPF (e.g., UPF 206), for establishing a MA PDU session (e.g., MA PDU session 204) between the WTRU (e.g., WTRU 202) and the UPF, each of which may be implemented in the system 200 in FIG. 2.

[0154] At 602, the UPF determines that the UPF is the PDM in a MA PDU session between the WTRU and UPF.

[0155] At 604, the UPF collects data related to one or more performance measurements associated with one or more access (e.g., 3GPP access or non-3GPP access) of the MA PDU session. [0156] At 606, the UPF selects an access of the one or more access (e.g., 3GPP access or non- 3 GPP access) for both UL traffic and DL traffic based at least in part on the one or more performance measurements collected at 604.

[0157] At 608, the UPF configures steering or switching for each of the UL traffic and the DL traffic using the selected access for the MA PDU session. The UPF is configured to steer or switch the DL traffic using the selected access for the MA PDU session, and the WTRU is configured, by the UPF, to steer or switch the UL traffic using the selected access for the MA PDU session. In some implementations, the UPF transmits, to the WTRU, an indication to steer or switch UL traffic using the selected access

[0158] At 610, the UPF performs the steering or the switching for the DL traffic using the selected access for the MA PDU session after being configured at 608.

[0159] FIG. 7 is a flowchart of an illustrative process, performed by an SMF (e.g., SMF 214), for establishing a MA PDU session (e.g., MA PDU session 204) between the WTRU (e.g., WTRU 202) and the UPF (e.g., UPF 206), each of which may be implemented in the system 200 in FIG. 2.

[0160] At 702, the SMF determines that the MA PDU session uses a SynATSSS mode.

[0161] At 704, the SMF determines that a first node (e.g., one of WTRU or UPF) is a PDM of the MA PDU session.

[0162] At 706, the SMF transmits a respective message to each node of the nodes, each respective message including SynATSSS indication data indicating whether a respective node (e.g., WTRU or UPF) may use the SynATSSS mode.

[0163] Although features and elements are provided above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations may be made without departing from its spirit and scope, as will be apparent to those skilled in the art. No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly provided as such. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods or systems.

[0164] The foregoing embodiments are discussed, for simplicity, with regard to the terminology and structure of wireless communication capable devices, (e.g., radio wave emitters and receivers). However, the embodiments discussed are not limited to these systems but may be applied to other systems that use other forms of electromagnetic waves or non-electromagnetic waves such as acoustic waves.

[0165] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used herein, the term "video" or the term "imagery" may mean any of a snapshot, single image and/or multiple images displayed over a time basis. As another example, when referred to herein, the terms "user equipment" and its abbreviation "UE", the term "remote" and/or the terms "head mounted display" or its abbreviation "HMD" may mean or include (i) a wireless transmit and/or receive unit (WTRU); (ii) any of a number of embodiments of a WTRU; (iii) a wireless-capable and/or wired-capable (e.g., tetherable) device configured with, inter alia, some or all structures and functionality of a WTRU; (iii) a wireless-capable and/or wired-capable device configured with less than all structures and functionality of a WTRU; or (iv) the like. Details of an example WTRU, which may be representative of any WTRU recited herein, are provided herein with respect to FIGs. 1 A-1D. As another example, various disclosed embodiments herein supra and infra are described as utilizing a head mounted display. Those skilled in the art will recognize that a device other than the head mounted display may be utilized and some or all of the disclosure and various disclosed embodiments can be modified accordingly without undue experimentation. Examples of such other device may include a drone or other device configured to stream information for providing the adapted reality experience.

[0166] In addition, the methods provided herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer- readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer. [0167] Variations of the method, apparatus and system provided above are possible without departing from the scope of the invention. In view of the wide variety of embodiments that can be applied, it should be understood that the illustrated embodiments are examples only, and should not be taken as limiting the scope of the following claims. For instance, the embodiments provided herein include handheld devices, which may include or be utilized with any appropriate voltage source, such as a battery and the like, providing any appropriate voltage.

[0168] Moreover, in the embodiments provided above, processing platforms, computing systems, controllers, and other devices that include processors are noted. These devices may include at least one Central Processing Unit ("CPU") and memory. In accordance with the practices of persons skilled in the art of computer programming, reference to acts and symbolic representations of operations or instructions may be performed by the various CPUs and memories. Such acts and operations or instructions may be referred to as being "executed," "computer executed" or "CPU executed."

[0169] One of ordinary skill in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. An electrical system represents data bits that can cause a resulting transformation or reduction of the electrical signals and the maintenance of data bits at memory locations in a memory system to thereby reconfigure or otherwise alter the CPU's operation, as well as other processing of signals. The memory locations where data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties corresponding to or representative of the data bits. It should be understood that the embodiments are not limited to the above-mentioned platforms or CPUs and that other platforms and CPUs may support the provided methods.

[0170] The data bits may also be maintained on a computer readable medium including magnetic disks, optical disks, and any other volatile (e.g., Random Access Memory (RAM)) or non-volatile (e.g., Read-Only Memory (ROM)) mass storage system readable by the CPU. The computer readable medium may include cooperating or interconnected computer readable medium, which exist exclusively on the processing system or are distributed among multiple interconnected processing systems that may be local or remote to the processing system. It should be understood that the embodiments are not limited to the above-mentioned memories and that other platforms and memories may support the provided methods.

[0171] In an illustrative embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions may be executed by a processor of a mobile unit, a network element, and/or any other computing device. [0172] There is little distinction left between hardware and software implementations of aspects of systems. The use of hardware or software is generally (but not always, in that in certain contexts the choice between hardware and software may become significant) a design choice representing cost versus efficiency tradeoffs. There may be various vehicles by which processes and/or systems and/or other technologies described herein may be effected (e.g., hardware, software, and/or firmware), and the preferred vehicle may vary with the context in which the processes and/or systems and/or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a mainly hardware and/or firmware vehicle. If flexibility is paramount, the implementer may opt for a mainly software implementation. Alternatively, the implementer may opt for some combination of hardware, software, and/or firmware.

[0173] The foregoing detailed description has set forth various embodiments of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples include one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, flowcharts, or examples may be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In an embodiment, several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), and/or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, may be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subj ect matter described herein may be distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include, but are not limited to, the following: a recordable type medium such as a floppy disk, a hard disk drive, a CD, a DVD, a digital tape, a computer memory, etc., and a transmission type medium such as a digital and/or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.).

[0174] Those skilled in the art will recognize that it is common within the art to describe devices and/or processes in the fashion set forth herein, and thereafter use engineering practices to integrate such described devices and/or processes into data processing systems. That is, at least a portion of the devices and/or processes described herein may be integrated into a data processing system via a reasonable amount of experimentation. Those having skill in the art will recognize that a typical data processing system may generally include one or more of a system unit housing, a video display device, a memory such as volatile and non-volatile memory, processors such as microprocessors and digital signal processors, computational entities such as operating systems, drivers, graphical user interfaces, and applications programs, one or more interaction devices, such as a touch pad or screen, and/or control systems including feedback loops and control motors (e.g., feedback for sensing position and/or velocity, control motors for moving and/or adjusting components and/or quantities). A typical data processing system may be implemented utilizing any suitable commercially available components, such as those typically found in data computing/communication and/or network computing/communication systems.

[0175] The herein described subject matter sometimes illustrates different components included within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures may be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality may be achieved. Hence, any two components herein combined to achieve a particular functionality may be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedia! components. Likewise, any two components so associated may also be viewed as being "operably connected", or "operably coupled", to each other to achieve the desired functionality, and any two components capable of being so associated may also be viewed as being "operably couplable" to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components.

[0176] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. [0177] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, where only one item is intended, the term "single" or similar language may be used. As an aid to understanding, the following appended claims and/or the descriptions herein may include usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim including such introduced claim recitation to embodiments including only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should be interpreted to mean "at least one" or "one or more"). The same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B." Further, the terms "any of followed by a listing of a plurality of items and/or a plurality of categories of items, as used herein, are intended to include "any of," "any combination of," "any multiple of," and/or "any combination of multiples of the items and/or the categories of items, individually or in conjunction with other items and/or other categories of items. Moreover, as used herein, the term "set" is intended to include any number of items, including zero. Additionally, as used herein, the term "number" is intended to include any number, including zero. And the term "multiple", as used herein, is intended to be synonymous with "a plurality".

[0178] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0179] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein may be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as "up to," "at least," "greater than," "less than," and the like includes the number recited and refers to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth.

[0180] Moreover, the claims should not be read as limited to the provided order or elements unless stated to that effect. In addition, use of the terms "means for" in any claim is intended to invoke 35 U.S.C. §112, 6 or means-plus-function claim format, and any claim without the terms "means for" is not so intended.

Claims

CLAIMS What is claimed is:

1. A method performed by a wireless transmit/receive unit (WTRU), the method comprising: determining that the WTRU is a primary decision maker (PDM) in a multi-access (MA) protocol data unit (PDU) session between the WTRU and a core network node; collecting data related to at least one performance measurement associated with one or more accesses of the MA PDU session; selecting an access of the one or more accesses for both uplink (UL) traffic and downlink (DL) traffic based at least in part on the at least one performance measurement; configuring steering or switching for each of the UL traffic and the DL traffic using the selected access for the MA PDU session; and performing the steering or the switching for the UL traffic using the selected access for the MA PDU session after being configured.

2. The method of claim 1, wherein determining that the WTRU is the PDM in the MA PDU session comprises: receiving a message comprising PDM indication data indicating that the WTRU is capable of being the PDM; and determining that the WTRU is the PDM based on the PDM indication data of the received message.

3. The method of claim 1, wherein determining that the WTRU is the PDM in the MA PDU session comprises: receiving a message comprising synchronized access traffic steering, switching, steering (SynATSSS) indication data indicating that the WTRU is capable of using a SynATSSS mode; and determining that the WTRU is the PDM based on one or more of (a) the SynATSSS indication data of the received message, (b) at least one characteristic of at least one of the UL traffic and DL traffic, and (c) information related to a policy of a network operator of a network to which the WTRU is communicatively coupled.

4. The method of any of claims 1 to 3, wherein collecting data related to the at least one performance measurement associated with one or more accesses of the MA PDU session comprises transmitting a message to the core network node to trigger a performance measurement of the at least one performance measurement.

5. The method of claim 4, wherein collecting data related to the at least one performance measurement associated with one or more accesses of the MA PDU session comprises receiving at least some of the data related to the at least one performance measurement from the core network node after transmitting the message to the core network node to trigger a performance measurement.

6. The method of any of claims 1 to 4, wherein the core network node is a user plane function (UPF).

7. The method of any of claims 1 to 5, further comprising transmitting a MA PDU session establishment or modification message to a session management function (SMF), wherein the MA PDU session establishment or modification message comprises SynATSSS indication data and PDM indication data for the WTRU.

8. The method of any of claims 1 to 7, wherein configuring the steering or switching for each of the UL traffic and the DL traffic using the selected access for the MA PDU session comprises: configuring the WTRU to steer or switch the UL traffic based on the selected access; and transmitting, to the core network node, an indication to steer or switch the DL traffic using the selected access.

9. The method of claim 8, further comprising receiving, from the core network node, a response indicating a successful steer or switch operation at the core network node.

10. A wireless transmit/receive unit (WTRU) configured to: determine that the WTRU is a primary decision maker (PDM) in a multi-access (MA) protocol data unit (PDU) session established between the WTRU and a core network node; collect data related to at least one performance measurement associated with one or more accesses of the MA PDU session; select an access of the one or more accesses for both uplink (UL) traffic and downlink (DL) traffic based at least in part on the at least one performance measurement; cause steering or switching to be configured for each of the UL traffic and the DL traffic using the selected access for the MA PDU session; and perform the steering or the switching for the UL traffic using the selected access for the MA PDU session after being configured.

11. The WTRU of claim 10, wherein to determine that the WTRU is the PDM in the MA PDU session, the WTRU is to: receive a message comprising PDM indication data indicating that the WTRU is capable of being the PDM; and determine that the WTRU is the PDM based on the PDM indication data of the received message.

12. The WTRU of claim 10, wherein to determine that the WTRU is the PDM in the MA PDU session, the WTRU is to: receive a message comprising synchronized access traffic steering, switching, steering (SynATSSS) indication data indicating that the WTRU is capable of using a SynATSSS mode; and determine that the WTRU is the PDM based on one or more of (a) the SynATSSS indication data of the received message, (b) at least one characteristic of at least one of the UL traffic and DL traffic, and (c) information related to a policy of a network operator of a network to which the WTRU is communicatively coupled.

13. The WTRU of any of claims 10 to 12, wherein to collect data related to the at least one performance measurement associated with one or more accesses of the MA PDU session the WTRU is to transmit a message to the core network node to trigger a performance measurement of the at least one performance measurement.

14. The WTRU of claim 13, wherein to collect data related to the at least one performance measurement associated with one or more accesses of the MA PDU session the WTRU is to receive at least some of the data related to the at least one performance measurement from the core network node after transmitting the message to the core network node to trigger a performance measurement.

15. The WTRU of any of claims 10 to 13, wherein the core network node is a user plane function (UPF).

16. The WTRU of any of claims 10 to 14, wherein the WTRU is further to transmit a MA PDU session establishment or modification message to a session management function (SMF), wherein the MA PDU session establishment or modification message comprises SynATSSS indication data and PDM indication data for the WTRU.

17. The WTRU of any of claims 10 to 16, wherein to cause steering or switching to be configured for each of the UL traffic and the DL traffic using the selected access for the MA PDU session the WTRU is to: cause to configure the WTRU to steer or switch the UL traffic based on the selected access; and transmit, to the core network node, an indication to steer or switch the DL traffic using the selected access.

18. The WTRU of claim 17, wherein the WTRU is further to receive, from the core network node, a response indicating a successful steer or switch operation at the core network node.

19. A method for establishing a multi-access (MA) protocol data unit (PDU) session between a wireless transmit/receive unit (WTRU) and a user plane function (UPF), wherein each of the WTRU and the UPF are respective nodes, the method comprising: determining, by a session management function (SMF), that the MA PDU session uses a synchronized access traffic steering, switching, splitting (SynATSSS) mode; determining, by the SMF, a first node of the respective nodes is a primary decision maker (PDM) in the MA PDU session; and transmitting, by the SMF, a respective message to each of the first node and a second node of the respective nodes, each respective message comprising SynATSSS indication data indicating whether the respective node may use the SynATSSS mode.

20. The method of claim 19, wherein transmitting the respective message to each of the first node and the second node comprises transmitting the respective message to each of the first node and the second node of the nodes wherein each respective message further comprises PDM indication data indicating whether the respective node may be the PDM.

21. The method of any of claims 19 and 20, wherein determining that the MA PDU session uses the SynATSSS mode comprises: receiving a MA PDU session establishment or modification message from the WTRU, the message comprising data indicating whether the WTRU may use DualSteer; and determining that the MA PDU session uses the SynATSSS mode based on the data indicating whether the WTRU may use Dual Steer.

22. The method of any of claims 19 to 21, wherein determining that the MA PDU session uses the SynATSSS mode comprises determining that the MA PDU session uses the SynATSSS mode based on policy and charging control (PCC) rules of the MA PDU session.

23. The method of any of claims 19 to 22, wherein determining the first node of the nodes is the PDM in the MA PDU session comprises determining the first node of the nodes is the PDM based on any one or more of (a) characteristics of uplink (UL) and downlink (DL) traffic transmitted through the MA PDU session, (b) a request from the WTRU, the request comprising PDM indication data of the WTRU, and (c) PDM indication data of the UPF.

24. A method performed by a user place function (UPF), the method comprising: determining that the UPF is a primary decision maker (PDM) in a multi-access (MA) protocol data unit (PDU) session between a wireless transmit/receive unit (WTRU) and the UPF; collecting data related to at least one performance measurement associated with one or more accesses of the MA PDU session; selecting an access of the one or more accesses for both uplink (UL) traffic and downlink (DL) traffic based at least in part on the at least one performance measurement; configuring steering or switching for each of the UL traffic and the DL traffic using the selected access for the MA PDU session; and performing the steering or the switching for the DL traffic using the selected access for the MA PDU session after being configured.