Method and apparatus for access traffic steering, switching, and splitting (ATSSS) redundant traffic steering modes - Patents.com

Abstract

Procedures, methods, etc. directed to access traffic steering, switching, and split redundancy traffic steering modes are provided. The method may include transmitting information indicative of a request to establish / modify a multi-access protocol data unit (PDU) session to a first network element, receiving information indicative of a response to the request to establish / modify the multi-access PDU session via a second network element, determining first and second values ​​of a plurality of metrics for a first and a second access network (AN), determining to transmit a PDU associated with the multi-access PDU session via one of (i) the first AN, (ii) the second AN, or (iii) the first and second ANs based on rules and the first and second values ​​of the plurality of metrics that satisfy respective conditions of the rules, and transmitting the PDU via one of the first AN, the second AN, or the first and second ANs.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of (i) U.S. Provisional Patent Application No. 63 / 303,722, filed January 27, 2022, and (ii) U.S. Provisional Patent Application No. 63 / 411,546, filed September 9, 2022, each of which is incorporated by reference herein. Summary of the Invention [Problem to be solved by the invention]

[0002] The present disclosure is directed to access traffic steering, switching, and splitting (ATSSS) redundant traffic steering modes for communications associated with multiple accesses (also referred to as "access networks") of one or more communication systems, including, but not limited to, methods, apparatus, systems, etc. [Brief description of the drawings]

[0003] A more detailed understanding may be had from the following detailed description, given in conjunction with the drawings that accompany this specification by way of example. Such drawing figures, like the detailed description, are illustrative. Thus, the figures and detailed description should not be considered as limiting, as other equally effective embodiments are possible and likely to be. Moreover, like reference numbers ("ref") within the drawings ("FIG") indicate like elements. [Figure 1A] FIG. 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] FIG. 1B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A, according to one embodiment. [Figure 1C]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, according to one embodiment. [Figure 1D] FIG. 1D is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communications system illustrated in FIG. 1A, according to one embodiment. [Diagram 2] FIG. 2 is a block diagram illustrating a WTRU with simultaneous 3GPP and non-3GPP access in Release 15. [Diagram 3] FIG. 3 is a block diagram illustrating a WTRU with simultaneous 3GPP and non-3GPP access in Release 16. [Figure 4] FIG. 4 is a flow diagram illustrating a redundant steering mode operation according to one embodiment. [Diagram 5] FIG. 5 is a signaling diagram illustrating enhanced packet data unit (PDU) session establishment to support redundancy steering mode according to one embodiment. [Figure 6] FIG. 6 is a signaling diagram illustrating WTRU notification of a change in the state of the redundancy steering mode. [Figure 7] FIG. 7 is a flowchart illustrating an example flow for use in connection with multi-access PDU session establishment and / or multi-access PDU session modification. [Figure 8] FIG. 8 is a flowchart illustrating an exemplary flow according to various embodiments. [Figure 9] FIG. 9 is a flowchart illustrating an exemplary flow according to various embodiments. [Figure 10] FIG. 10 is a flowchart illustrating an exemplary flow according to various embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0004] Introduction In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the 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. Furthermore, embodiments and examples not specifically described herein may be practiced in place of or in combination with the embodiments and other examples explicitly, implicitly and / or inherently described, disclosed or otherwise provided herein (collectively "provided"). Although various embodiments are described and / or claimed herein in which apparatus, systems, devices, etc. and / or any elements thereof perform operations, processes, algorithms, functions, etc. and / or any portions thereof, it should be understood that any embodiment described and / or claimed herein assumes that any apparatus, system, device, etc. and / or any elements thereof are configured to perform any operations, processes, algorithms, functions, etc. and / or any portions thereof.

[0005] Exemplary Communication System 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. Communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcasts, etc., to multiple wireless users. Communications system 100 may enable multiple wireless users to access such content through sharing of system resources, including wireless bandwidth. For example, the communications system 100 may use one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0006] 1A, communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, public switched telephone network (PSTN) 108, Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of 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 “STA,” may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain situations), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c, and 102d may be referred to interchangeably as a UE.

[0007] The communications system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communications networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base station transceiver station (BTS), a Node B, an eNode B, a Home Node B, a Home eNode B, a gNB, an NR Node B, a site controller, an access point (AP), a wireless router, etc. Although the base stations 114a, 114b are each illustrated as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0008] 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), a relay node, 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 cells (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide wireless service coverage for a particular geographic area, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell, for example, using beamforming to transmit and / or receive signals in a desired spatial direction.

[0009] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d via 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).

[0010] More specifically, as noted above, the communications system 100 may be a multiple access system, but may use one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base stations 114a of 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 communications 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).

[0011] In one 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).

[0012] In one 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).

[0013] In one 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, e.g., using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to and from multiple types of base stations (e.g., eNBs and gNBs).

[0014] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as IEEE 802.11 (i.e., Wireless Fidelity, WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access, WiMAX), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), or the like.

[0015] 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a localized area, such as an office, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology, such as IEEE 802.11, to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology, such as IEEE 802.15, to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may establish a picocell or a femtocell using a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.). As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not need to access the Internet 110 via the CN 106 / 115.

[0016] The RAN 104 / 113 may communicate with the CN 106 / 115, which may be any type of network configured to provide voice, data, application, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have various quality of service (QoS) requirements, such as, for example, different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high level security functions such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may communicate directly or indirectly with other RANs that use 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 utilize NR radio technology, the CN 106 / 115 may also communicate with another RAN (not shown) using GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0017] The CN 106 / 115 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network providing 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 transmission control protocol (TCP), user datagram protocol (UDP), and / or internet protocol (IP) of the TCP / IP Internet protocol suite. The networks 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may use the same RAT as the RANs 104 / 113 or a different RAT.

[0018] 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 a base station 114a, which may employ a cellular-based wireless technology, and a base station 114b, which may employ an IEEE 802 wireless technology.

[0019] Figure 1B is a system diagram illustrating an example WTRU 102. As shown in Figure 1B, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be understood that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0020] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. 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. Although FIG. 1B illustrates the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0021] The transmit / receive element 122 may be configured to transmit or receive signals to or from a base station (e.g., base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0022] 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0023] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as, for example, NR and IEEE 802.11.

[0024] The processor 118 of the WTRU 102 may be coupled to and may receive user-entered data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as non-removable memory 130 and / or removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, etc. 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 home computer (not shown).

[0025] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components in the WTRU 102. The power source 134 may be any suitable device for providing power to the WTRU 102. For example, the power source 134 may include one or more dry batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0026] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information by way of any suitable location determination method while remaining consistent with an embodiment.

[0027] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, which 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.

[0028] The WTRU 102 may include a full-duplex radio where transmission and reception of some or all of the signals (e.g., associated with a particular subframe for both the uplink (e.g., for transmission) and downlink (e.g., for reception)) may be parallel and / or simultaneous. The full-duplex radio may include an interference management unit 139 to reduce and or substantially eliminate self-interference either through hardware (e.g., chokes) or signal processing via a processor (e.g., via a separate processor (not shown) or processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for transmission and reception of some or all of the signals (e.g., associated with a particular subframe for either the uplink (e.g., for transmission) or downlink (e.g., for reception)).

[0029] 1C is a system diagram illustrating the RAN 104 and the CN 106, according to one embodiment. As mentioned above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also communicate with the CN 106.

[0030] The RAN 104 may include eNodeBs 160a, 160b, 160c, although it will be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 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 eNodeBs 160a, 160b, 160c may implement MIMO technology. Thus, the eNodeB 160a may, for example, use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0031] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink (UL) and / or downlink (DL), etc. As shown in FIG 1C, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0032] 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. Although each of the foregoing elements is illustrated as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0033] The MME 162 may be connected to each of the eNodeBs 162a, 162b, 162c in the RAN 104 via an S1 interface and may function as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attachment of the WTRUs 102a, 102b, 102c, etc. 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.

[0034] The SGW 164 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-eNodeB handover, triggering paging when DL data is available to the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0035] The SGW 164 may be connected to a 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.

[0036] 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 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 other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0037] Although the WTRU is depicted in FIGS. 1A-1D as a wireless terminal, in certain representative embodiments, it is contemplated that such a terminal may use a wired communications interface (e.g., temporarily or permanently) with the communications network.

[0038] In an exemplary embodiment, the other network 112 may be a WLAN.

[0039] A WLAN in infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) of the BSS and one or more stations (STAs) associated with the AP. The AP may have access or interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic into and / or out of the BSS. Traffic originating from outside the BSS to the STA may arrive through the AP and be delivered to the STA. Traffic originating from the STA to a destination outside the BSS may be sent to the AP to be delivered to the respective destination. Traffic between STAs within the BSS may be sent, for example, through the AP, where the source STA may send traffic to the AP, which may deliver the traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between (e.g., directly between) the source STA and the destination STA using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS communication mode is sometimes referred to herein as an "ad-hoc" communication mode.

[0040] When using an 802.11ac infrastructure mode of operation or a similar mode of operation, an AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width that is dynamically set via signaling. The primary channel may be the operating channel of the BSS, but may be used by STAs to establish a connection with the AP. In certain representative embodiments, for example, in an 802.11 system, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented. With CSMA / CA, STAs (e.g., all STAs), 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.

[0041] A High Throughput (HT) STA may use a 40 MHz wide channel for communication, which may be formed, for example, through a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels.

[0042] A Very High Throughput (VHT) STA may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. A 40 MHz and / or 80 MHz channel may be formed by combining multiple contiguous 20 MHz channels. A 160 MHz channel may be formed by combining eight 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, after channel encoding, the data may pass through a segment parser that may split the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time domain processing may be performed separately on each stream. The streams may be mapped to two 80 MHz channels and the data may be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration may be reversed and the combined data may be sent to the Medium Access Control (MAC).

[0043] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter-type control / machine-type communication, such as MTC devices in macro coverage areas. MTC devices may have limited capabilities, including certain capabilities, for example, support for (e.g., support only for) certain and / or limited bandwidths. MTC devices may include batteries with above-threshold battery life (e.g., to maintain very long battery life).

[0044] WLAN systems that may support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that may be designated as a primary channel. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be configured and / or limited by the STAs among all STAs operating in the BSS that support the smallest bandwidth operating mode. In an 802.11ah embodiment, the primary channel may be 1 MHz wide for STAs (e.g., MTC-type devices) that support (e.g., only) the 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) configuration may depend on the status of the primary channel. For example, if the primary channel is active due to a STA (that only supports the 1 MHz mode of operation) transmitting to the AP, the entire available frequency band may be considered active even though most of the frequency band may remain dormant and available.

[0045] In the United States, the available frequency bands that can be used by 802.11ah are 902MHz to 928MHz. In South Korea, the available frequency bands are 917.5MHz to 923.5MHz. In Japan, the available frequency bands are 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz depending on the country code.

[0046] 1D is a system diagram illustrating the RAN 113 and the CN 115, according to one embodiment. As mentioned above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also communicate with the CN 115.

[0047] The RAN 113 may include gNBs 180a, 180b, 180c, although it will be understood that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to transmit and / or receive signals to the gNBs 180a, 180b, 180c. Thus, the gNB 180a may transmit and / or receive wireless signals to and from the WTRU 102a, for example, using multiple antennas. 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 an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In one embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or 180c).

[0048] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of different or scalable lengths (e.g., including different numbers of OFDM symbols and / or lasting different lengths of absolute time).

[0049] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c without accessing another RAN (e.g., eNodeBs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, 102c may utilize one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in unlicensed bands. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate with and connect to a gNB 180a, 180b, 180c while also communicating with and connecting to another RAN, such as an eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeBs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0050] 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 uplink (UL) and / or downlink (DL), support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D, the gNBs 180a, 180b, 180c may communicate with each other via an Xn interface.

[0051] 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. Although each of the foregoing elements is illustrated as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0052] 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 function as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, etc. The network slicing may be used by the AMF 182a, 182b to customize the CN support of the WTRUs 102a, 102b, 102c based on the type of service utilizing the WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, etc. The AMF 182a, 182b may provide a control plane function for switching between the RAN 113 and other RANs (not shown) employing other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0053] The SMFs 183a, 183b may be connected to the AMFs 182a, 182b in the CN 115 via an N11 interface. The SMFs 183a, 183b may also be connected to the UPFs 184a, 184b in the CN 115 via an N4 interface. The SMFs 183a, 183b may select and control the UPFs 184a, 184b and configure the routing of traffic through the UPFs 184a, 184b. The SMFs 183a, 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0054] The UPFs 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPFs 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, etc.

[0055] The CN 115 may facilitate communication with other networks. For example, the CN 115 may include or 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 other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b through the UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0056] 1A-1D and the corresponding description thereof, one or more or all of the functions described herein with respect to one or more of the WTRUs 102a-d, base stations 114a-b, eNodeBs 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 devices described herein may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0057] The emulation device may be designed to implement one or more tests of other devices in a lab environment and / or an operator network environment. For example, one or more emulation devices may perform one or more or all functions while fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices in the communication network. One or more emulation devices may perform one or more or all functions while temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for testing purposes and / or may implement the testing using terrestrial wireless communication.

[0058] The one or more emulation devices may perform one or more functions, inclusive, while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in test scenarios in a test lab and / or in an undeployed (e.g., test) wired and / or wireless communication network to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (which may include, for example, one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0059] overview SUMMARY Disclosed herein are methods, apparatus, systems, etc. directed to Access Traffic Steering, Switching, and Splitting (ATSSS) redundant traffic steering modes.

[0060] In various embodiments, a method for and / or use in connection with an ATSSS redundancy traffic steering mode may be implemented in a WTRU and may include any of: transmitting first information to a first network element indicating one of a request to establish a multi-access protocol data unit (PDU) session or a request to modify a multi-access PDU session; receiving second information via a second network element indicating a response to the one of the request to establish a multi-access PDU session or the request to modify a multi-access PDU session; determining a first value of a plurality of metrics for the first access network; determining a second value of a plurality of metrics for the second access network; determining to transmit a PDU associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks based on rules for the redundancy steering mode and the first and second values ​​of the plurality of metrics that satisfy respective conditions of the rules; and transmitting the PDU via the first access network, the second access network, or one of the first and second access networks.

[0061] In various embodiments, a method for and / or use in connection with an ATSSS redundancy traffic steering mode may be implemented in a WTRU and may include any of: sending first information to a first network element indicating one of a request to establish a multi-access PDU session or a request to modify a multi-access PDU session; receiving second information via a second network element indicating a response to the one of the request to establish a multi-access PDU session or the request to modify a multi-access PDU session; determining a first value of a plurality of metrics for the first access network; determining a second value of a plurality of metrics for the second access network; determining to receive a PDU associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks based on rules for the redundancy steering mode and the first and second values ​​of the plurality of metrics that satisfy respective conditions of the rules; and receiving the PDU via the first access network, the second access network, or one of the first and second access networks.

[0062] In various embodiments, a method for and / or use in connection with an ATSSS redundancy traffic steering mode may be implemented in a WTRU and may include any of: sending first information to a first network element indicating one of a request to establish a multi-access protocol data unit (PDU) session or a request to modify a multi-access PDU session; receiving second information via a second network element indicating a response to the one of the request to establish a multi-access PDU session or the request to modify a multi-access PDU session; determining to transmit or receive a PDU associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks based on rules for the redundancy steering mode, first values ​​of a plurality of metrics for the first access network and second values ​​of a plurality of metrics for the second access network that satisfy respective conditions of the rules; and performing one of transmitting and receiving the PDU via the first access network, the second access network, or one of the first and second access networks.

[0063] In various embodiments, a method for and / or use in connection with an ATSSS redundancy traffic steering mode may be implemented in a WTRU and may include transmitting, to a first network element, first information indicating one of a request to establish a multi-access PDU session or a request to modify a multi-access PDU session, and one or more redundancy steering mode capabilities of the WTRU; and receiving, via a second network element, second information indicating a response to the one of the request to establish a multi-access PDU session or the request to modify a multi-access PDU session, and one or more rules for the redundancy steering mode including the rules. and determining to transmit or receive a PDU associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks based on one of the rules and a first value of the plurality of metrics for the first access network and a second value of the plurality of metrics for the second access network satisfying respective conditions of the rules; and performing one of transmitting and receiving the PDU via the first access network, the second access network, or one of the first and second access networks.

[0064] In various embodiments, an apparatus for use for and / or in connection with an ATSSS redundancy traffic steering mode may be configured to receive, via a second network element during a registration procedure, third information indicating that traffic steering is supported; send, via the first network element, first information indicating one of a request to establish a multi-access PDU session or a request to modify the multi-access PDU session; receive, via the second network element, second information indicating a response to one of the request to establish a multi-access PDU session or the request to modify the multi-access PDU session; determine a first value of a plurality of metrics for the first access network; determine a second value of the plurality of metrics for the second access network; and based on rules for the redundancy steering mode and the first and second values ​​of the plurality of metrics that satisfy respective conditions of the rules, determine to transmit a PDU associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks, and / or transmit the PDU via one of the first access network, the second access network, or the first and second access networks.

[0065] In various embodiments, an apparatus for use for and / or in connection with an ATSSS redundancy traffic steering mode may be configured to: send first information indicative of one of a request to establish a multi-access protocol data unit (PDU) session or a request to modify a multi-access PDU session to a first network element; receive second information indicative of a response to the one of the request to establish a multi-access PDU session or the request to modify a multi-access PDU session via a second network element; determine a first value of a plurality of metrics for the first access network; determine a second value of the plurality of metrics for the second access network; determine to receive a PDU associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks based on rules for the redundancy steering mode and the first and second values ​​of the plurality of metrics that satisfy respective conditions of the rules; and receive the PDU via one of the first access network, the second access network, or the first and second access networks.

[0066] In various embodiments of the method and apparatus, the PDU is a PDU of an SDF associated with a multi-access PDU session. In various embodiments of the method and apparatus, based on the rule, a state transition of the redundancy steering mode from inactive to active is performed on condition that only a single access network of the first and second access networks cannot meet the requirements of the SDF. In various embodiments of the method and apparatus, based on the rule, a state transition of the redundancy steering mode from active to inactive is performed on condition that only a single access network of the first and second access networks can meet the requirements of the SDF.

[0067] In various embodiments of the method and apparatus, information is received from the network indicating a duration of the state of the redundant steering mode. In various embodiments of the method and apparatus, information is received for the duration indicating whether the first or second access network should be used. In various embodiments of the method and apparatus, measurements on either the removed first or second access network are paused for the duration. In various embodiments of the method and apparatus, the WTRU transitions to an IDLE mode on the access that is removed for the duration.

[0068] In various embodiments of the method and apparatus, the first information indicates one or more redundancy steering mode capabilities of the WTRU, and the second information indicates one or more rules for the redundancy steering modes, including the rules.

[0069] In various embodiments of the method and apparatus, the multiple metric network element is an access and mobility management function. In various embodiments of the method and apparatus, the second network element is a base station. In various embodiments of the method and apparatus, the second network element is a base station associated with the first access network, the second access network, or a second access network different from a first one of the first and second access networks.

[0070] In various embodiments of the method and apparatus, the plurality of metrics includes any two of packet loss rate, delay, delay variability, and load.

[0071] In various embodiments of the method and apparatus, the one or more rules for the redundancy steering mode include information indicating an initial state of the redundancy steering mode is one of active and inactive. In various embodiments of the method and apparatus, an initial PDU transmission of the SDF is transmitted via one of the first access network, the second access network, or the first and second access networks based on the initial state of the redundancy steering mode being one of active and inactive.

[0072] In various embodiments of the method and apparatus, the one or more rules include information indicative of a measurement configuration for the plurality of metrics. In various embodiments of the apparatus, the circuitry is configured to expect to receive the information indicative of the at least one rule for the redundant steering mode based on transmitting the first information indicative of the one or more redundant steering mode capabilities of the WTRU. In various embodiments of the method, the method can include expecting to receive the information indicative of the at least one rule for the redundant steering mode based on transmitting the first information indicative of the one or more redundant steering mode capabilities of the WTRU.

[0073] In various embodiments of the method, the method can receive third information indicating that traffic steering is supported via the second network element during the registration procedure. In various embodiments of the method, determining to transmit the PDU can include determining to transmit the PDU via the first and second access networks based on the rule, first and second values ​​of the plurality of metrics satisfying respective conditions of the rule, and the rule indicating that PDU duplication for the redundancy steering mode is inactive, and transmitting the PDU can include transmitting the PDU based on the indicated PDU duplication.

[0074] In various embodiments of the apparatus, the circuitry configured to determine to transmit or receive a PDU includes circuitry configured to determine to transmit the PDU via the first and second access networks based on the rule, first and second values ​​of the plurality of metrics that satisfy respective conditions of the rule, and the rule indicating that PDU duplication for the redundancy steering mode is inactive, and the circuitry configured to transmit the PDU includes circuitry configured to transmit the PDU based on the indicated PDU duplication.

[0075] In various embodiments, some methods may be implemented in a WTRU and may include any of receiving first information from a network element during a registration procedure indicating that traffic steering is supported; transmitting second information to the first network element that may indicate one or more redundant steering mode capabilities of the WTRU; receiving third information, e.g., via the second network element, that may indicate one or more rules for the redundant steering mode; and transmitting a PDU associated with the multi-access PDU session via at least one of the first and second access networks, where (i) the PDU is transmitted via the first and second access networks based on a first rule of the rules and a first value of two or more metrics associated with each of the first and second access networks, and (ii) the PDU is transmitted via one of the first and second access networks based on a second rule of the rules and a second value of the two or more metrics associated with each of the first and second access networks.

[0076] In various embodiments, the first network element may be, for example, an AMF. In various embodiments, the first information may be or may include a multi-access PDU session support indicator.

[0077] In various embodiments, the redundancy steering mode capability of the WTRU may be or include an ATSSS capability. In various embodiments, the ATSSS capability (redundancy steering mode capability) may include any of support for a redundant traffic steering mode, support for duplication detection, and support for a specific steering function. In various embodiments, the second information may indicate one of a request to establish a multi-access protocol PDU session or a request to modify a multi-access PDU session. As an example, the second information may be a PDU session establishment request or a PDU session modification request that has information about the redundancy steering mode capability of the WTRU.

[0078] In various embodiments, the third information may indicate a response to one of the requests to establish a multi-access PDU session or to modify the multi-access PDU. As an example, the third information may be a PDU session establishment request accept message having information regarding (e.g., indicative of) at least one of the ATSSS rules for the redundancy steering mode and other rules for the redundancy steering mode. In various embodiments, the WTRU may expect to receive information indicative of at least one rule for the redundancy steering mode based on transmitting the first information indicative of one or more redundancy steering mode capabilities of the WTRU.

[0079] In various embodiments, at least one of the one or more rules may indicate that PDU duplication for the redundancy steering mode is inactive (or active), and the WTRU may be configured to transmit a PDU based on the indicated PDU duplication based on the absence of any values ​​for one or more of the metrics associated with each of the first and second access networks. In various embodiments, the first rule may indicate using the first and second access networks, provided that neither (i) a first value of the two or more metrics associated with the first access network nor (ii) a first value of the two or more metrics associated with the second access network meets a respective threshold value.

[0080] In various embodiments, some methods may be implemented in a WTRU and may include: transmitting, by the WTRU, a packet data unit (PDU) session establishment request having information regarding the WTRU's redundancy steering mode capabilities; receiving, by the WTRU, a PDU session establishment request accept message having information regarding (e.g., indicative of) at least one of an ATSSS rule for the redundancy steering mode and other rules for the redundancy steering mode; and transmitting one or more PDUs in the redundancy steering mode in accordance with the ATSSS rule or at least one of the other rules.

[0081] In various embodiments, transmitting the one or more PDUs may include toggling between an active state and an inactive state of the redundancy steering mode based on one or more trigger conditions. Alternatively, the method may include either toggling between an active state and an inactive state of the redundancy steering mode based on one or more trigger conditions and transmitting the one or more PDUs based on an active state or an inactive state resulting from the toggling (e.g., each of one or more instances of toggling).

[0082] In various embodiments, transmitting the one or more PDUs may include monitoring one or more trigger conditions for a transition from the active redundancy steering mode to the inactive redundancy steering mode based on one or more performance metrics. Alternatively, the method may include either monitoring one or more trigger conditions for a transition from the active redundancy steering mode to the inactive redundancy steering mode based on the one or more performance metrics and detecting (determining) the transition and detecting (determining) an active state prior to the transition or transmitting (determining) the transition based on an inactive state.

[0083] In various embodiments, the method may include receiving, by the WTRU, an indication from a user plane function (UPF) to trigger a state transition of the redundancy steering mode, and toggling between an active state and an inactive state of the redundancy steering mode in response to the received indication.

[0084] In various embodiments, the method may include determining, by the WTRU, a trigger condition for a state transition of the redundancy steering mode based on the mobility event.

[0085] In various embodiments, the method may include either receiving, by the WTRU, a signal from a performance management function (PMF) for the WTRU to notify a UPF of a change in the state of the redundancy steering mode, and in response to the signal, notifying, by the WTRU, the UPF of the change in the state of the redundancy steering mode.

[0086] In various embodiments, the apparatus includes a WTRU having a transmitter, a receiver, a processor, and a memory, the WTRU configured to perform a method according to at least one of the various embodiments disclosed above (and below).

[0087] Exemplary methods and apparatus for access traffic steering, switching, and splitting (ATSSS) redundant traffic steering modes - Patents.com Representative ATSSS in 3GPP Most WTRUs are capable of both 3GPP and non-3GPP access. This capability provides network operators with flexibility in deciding which access network to use for a service data flow (SDF). According to 3GPP Release 15, a UE 200 that uses both 3GPP and non-3GPP access networks must establish independent single-access PDU sessions 202A and 202B on the 3GPP and non-3GPP access networks, respectively, as shown in FIG. 2. The term "packet data unit" and its abbreviation "PDU" may be referred to interchangeably with the term "protocol data unit" (e.g., as part of the Third Generation Partnership Project (3GPP)). rd 3GPP TS 23.501 v17.3.0); Technical Specification Group Services and System Aspects; System Architecture for 5G Systems (5GS); Stage 2, (Release 17), 3GPP TS 23.501 v17.3.0).

[0088] However, it was clear that such an architecture could not fully utilize the flexibility. In Release 16, the concept of a multi-access PDU session 302 was introduced, as shown in Figure 3, to allow the uplink and downlink traffic of the SDF to be more easily steered, switched, or split between 3GPP and non-3GPP access networks. As used herein, a multi-access PDU session is a PDU session whose traffic may be transmitted over one, some, or all of multiple access networks. For example, the traffic of the multi-access PDU session 302 may be transmitted over a first access network (e.g., a 3GPP access network) of two access networks, over a second access network (e.g., a non-3GPP access network) of two access networks, or over both of two access networks (e.g., a 3GPP access network and a non-3GPP access network).

[0089] The new architecture introduced in Release 16 has been further enhanced in Release 17 to enable the following "steering capabilities" namely: (i) access traffic steering, (ii) access traffic switching, and (iii) access traffic splitting.

[0090] The access traffic steering function is a procedure whereby (i) an access network for a new data flow is selected and (ii) the traffic of that data flow is forwarded through the selected access network. Access traffic steering is applicable between 3GPP accesses and non-3GPP accesses.

[0091] The access traffic switching function is a procedure whereby all traffic of an ongoing data flow is moved from one access network to another in a way that maintains the continuity of the data flow. Access traffic splitting is applicable between 3GPP and non-3GPP accesses.

[0092] The access traffic splitting function is a procedure where the traffic of a data flow is split across multiple access networks. Access traffic splitting is applicable between 3GPP and non-3GPP accesses. When traffic splitting is applied to a data flow, some traffic of the data flow is forwarded over one access and some other traffic of the same data flow is forwarded over another access. Access traffic splitting is applicable between 3GPP and non-3GPP accesses.

[0093] The steering function in the ATSSS-enabled WTRU can steer, switch, and / or split the traffic of multi-access PDU sessions across 3GPP and non-3GPP accesses. Two steering functions have been standardized. The first is an upper layer steering function that operates above the IP layer. In Release 17, only one upper layer steering function was specified, which applies the Multipath TCP (MPTCP) protocol (IETF RFC 8684) and is called the "MPTCP function". This function is only applicable to TCP traffic. The second is a lower layer steering function that operates below the IP layer. In Release 17, only one type of lower layer steering function is defined, which is called the "ATSSS lower layer function" or "ATSSS-LL function". The ATSSS-LL function is applicable to Ethernet and IP (i.e., TCP and UDP). The steering function (e.g., either the MPTCP function or the ATSSS-LL function) is a new function that is present in both the WTRU and the UPF (i.e., at the endpoints of the PDU sessions).

[0094] For each steering function, one or more steering modes are supported. The steering mode determines how the traffic of the matching SDF should be distributed across 3GPP and non-3GPP access networks. As of Release 16, the supported steering modes include (i) active-standby steering mode, (ii) minimum-latency steering mode, (iii) load-sharing steering mode, and (iv) priority-based steering mode.

[0095] The active-standby steering mode is used to steer traffic to one access network (active access network) when such access network is available, and to switch to steering traffic to another access network (standby access network) when one (active) access network becomes unavailable.

[0096] Minimum delay steering mode is used to steer traffic to the access network that is determined to have the minimum round trip time (RTT). The WTRU and UPF measure their respective RTTs to determine which access network has the lowest RTT. According to the 3GPP specifications as of Release 16, minimum delay steering mode can only be used for non-guaranteed bit rate (non-GBR) SDFs.

[0097] The load balancing steering mode is used to split the traffic across both access networks according to the ratio of the amount of traffic to be transmitted over 3GPP access and non-3GPP access. According to the 3GPP specifications as of Release 16, the load balancing steering mode is only applicable to non-GBR SDFs.

[0098] The priority-based steering mode is used to steer all traffic matching the rules published by the Policy Charging Control (PCC) network element to a high-priority access network until such access network is determined to be congested. After the high-priority access network is determined to be congested, part of the traffic is also sent to a lower priority access, i.e., the traffic is split between two access networks. According to the 3GPP specifications as of Release 16, the priority-based steering mode can only be used for non-GBR SDFs.

[0099] The active standby, minimum latency, load balancing, and priority-based steering modes were enhanced in Release 17. For the load balancing steering mode, 3GPP added a steering mode indicator. The steering mode indicator indicates that the WTRU can change the default steering parameters in the steering mode percentage provided by the network and adjust the traffic steering based on its own decision. Only one of the following steering mode indicators may be provided: (i) autonomous load balance indicator and (ii) UE assisted indicator.

[0100] When the autonomous load balance indicator is provided to the WTRU, the WTRU may ignore the percentage in the steering mode component (i.e., the default percentage provided by the network) and autonomously determine its own percentage for traffic splitting in a manner that maximizes the aggregate bandwidth in the uplink direction. When the UE assistance indicator is provided to the WTRU by the network, the UE assistance indicator indicates to the WTRU that (a) the WTRU may determine how to distribute the uplink traffic of the matching SDF based on the WTRU's internal state (e.g., when the WTRU is in a special internal state, e.g., a lower battery level), and (b) the WTRU may inform the corresponding UPF how the WTRU decides to distribute the uplink traffic of the matching SDF. If the WTRU is not in a special internal state, the WTRU shall distribute the uplink traffic as indicated by the network, even if the UE assistance indicator is provided by the network.

[0101] In addition, for the load sharing steering mode, 3GPP introduced thresholds for the WTRU and UPF to apply to measurements made for (or in connection with) the load sharing steering mode. The per-access network thresholds can be either values ​​for RTT measurements or values ​​for packet loss rate (PLR) measurements. When at least one measured parameter (i.e., RTT or PLR) on one access network exceeds a threshold (provided to the WTRU and UPF), the WTRU and UPF may stop transmitting traffic on this access network, or may continue to transmit traffic on this access network, but should reduce the traffic on this access network by an implementation-specific amount and transmit the reduced amount of traffic on the other access network. When all measured parameters (i.e., RTT and PLR) for both accesses do not exceed the provided thresholds, the WTRU and UPF shall apply a fixed split percentage.

[0102] For the priority-based steering mode, 3GPP also introduced thresholds for the WTRU and UPF to apply to measurements made for (or in connection with) the priority-based steering mode. The per-access-network thresholds can be either values ​​for RTT measurements or values ​​for PLR measurements. These thresholds should be taken into account by the WTRU and UPF to determine when an access network is congested. For example, when a measured parameter (i.e., RTT or PLR) on a high-priority access network exceeds a threshold (provided to the WTRU and UPF), the WTRU and UPF may consider the high-priority access as congested and send traffic to the low-priority access network as well.

[0103] Rules are required in both the WTRU and the UPF to enable the steering mode for each of the steering functions. These rules are generated by the SMF based on information known to the Policy Control Function (PCF) and sent to the WTRU to determine the switching function and switching mode to use for uplink traffic (ATSSS rules) and to the UPF to determine the switching function and switching mode to use for downlink traffic (N4 rules).

[0104] In addition, to support some of the steering modes, a Performance Management Function (PMF) protocol is required in the WTRU and UPF to perform measurements required for switching mode decision (RTT measurements, access availability / unavailability reports, PLR measurements).

[0105] 3GPP Technical Specification Group Service and System Aspects (TSG SA) Workgroup 1 (SA1) in 3GPP; 3GPP TS 22.261 V18.5.0, Service Requirements for 5G Systems, describes several vertical markets and applications where 5G systems are expected to be able to provide data transfer capabilities with strict performance requirements in terms of very low latency and high reliability requirements. These use cases are often referred to as demand URLLC. Solutions for URLLC specification cases are addressed both on the access network side (e.g., preemption) and on the core network side (Session and Service Continuity (SSC) mode, dual connectivity based end-to-end redundant user plane paths). However, these solutions do not consider potential redundancy due to multi-access PDU sessions.

[0106] Among the problems addressed by the various disclosed embodiments is how and when to use the redundant steering mode.

[0107] In both cases (i.e., static redundancy steering mode and dynamic redundancy steering mode), the legacy PDU session establishment procedure does not support the new steering mode.

[0108] New criteria and / or triggers for the dynamic steering mode are disclosed below, including new criteria and / or triggers for both the WTRU and the UPF to determine when to activate or deactivate the steering mode. The criteria and / or triggers may be based on existing measurements and new measurements tailored to the URLLC use case.

[0109] Features, methods, and techniques disclosed herein include: (1) an enhanced PDU session establishment procedure including ATSSS capability for a redundancy steering mode and / or ATSSS rules and WTRU rules for the redundancy steering mode; (2) a redundancy steering mode that may toggle / switch between an active state and an inactive state based on a trigger condition; (3) monitoring a trigger condition for a transition of the redundancy steering mode from active to inactive based on a performance metric; (4) monitoring a trigger condition for a transition of the redundancy steering mode from inactive to active based on a performance metric; (5) receiving, at the WTRU, an instruction from the UPF to trigger a state transition of the redundancy steering mode; (6) determining, at the WTRU, a trigger condition for a state transition of the redundancy steering mode based on a mobility event, and (7) a PMF signaling exchange for the WTRU to inform the UPF about a change in the state of the redundancy steering mode.

[0110] Representative overall operation In the following, the term "Service Data Flow" or its abbreviation "SDF" is used to describe traffic from an application that may or may be affected by the steering mode. It may be identified by an IP 5-tuple, by a specific application ID, or by any identifier that can identify a flow of an application. The terms "access" and "multiple accesses" may be referred to interchangeably with the terms "access network" and "multiple access networks" (e.g., respectively), and the use of the term "network" in the terms "access network" and "multiple access networks" does not imply that any one of the "access network" and / or "access networks" necessarily includes more than one network element.

[0111] The WTRU and the UPF may be configured in a multi-access PDU session, and the WTRU and the UPF may transmit PDUs via a 3GPP path and / or a non-3GPP path. In the following, the term "access path" may be used interchangeably with "access leg."

[0112] The redundancy steering mode allows PDUs to be replicated and transmitted over two (or more) access networks (e.g., a 3GPP access network and a non-3GPP access network). In the following, the terms "static redundancy steering mode" and "static replication" are used interchangeably and should be understood as a steering mode that does not change very dynamically. It is typically expected to be fixed for the duration of the SDF. All PDUs of this SDF can follow the steering mode and be transmitted over two (or more) access networks (e.g., a 3GPP access network and a non-3GPP access network). Static replication means that all PDUs of the SDF are replicated on two (or more) access networks.

[0113] In the following, the terms "latency requirement" and "delay requirement" are used interchangeably.

[0114] In the following, the terms "dynamic redundancy steering mode" and "dynamic replication" are used interchangeably and should be understood as a non-static steering mode. The dynamic redundancy steering mode may have two (or more) states and may be in only one of the two (or more) states at any given time. The first state may be an active state (replication occurs) and the second state may be an inactive state (no replication). The dynamic redundancy steering mode may undergo a state change from an active state to an inactive state and / or from an inactive state to an active state. Being in or being triggered to transition to a new state (e.g., one of the active state or the inactive state), or transitioning to a new state may be considered as another state of the dynamic redundancy steering mode. However, for simplicity of description herein, the dynamic redundancy steering mode is considered to remain in a current state (e.g., active or inactive) until a transition to a new state (e.g., the opposite of the current state) is completed.

[0115] In the active state, the SDF PDUs may be transmitted over two (or more) access networks (e.g., a 3GPP access network and a non-3GPP access network). In the inactive state, the SDF PDUs may be transmitted only over a single access network (e.g., one of the 3GPP access network or the non-3GPP access network) using another steering mode such as an active-standby mode. During the active state, the WTRU and the UPF may monitor a trigger set (e.g., a first trigger set ("Trigger Set 1")) to determine whether to continue transmitting on two (or more) access networks (i.e., remain in the active state) or transmit PDUs only on a single access network (i.e., transition to the inactive state). During the inactive state, the WTRU and the UPF may monitor a trigger set (e.g., a second trigger set ("Trigger Set 2")) to determine whether to continue transmitting on a single access network (i.e., remain in the inactive state) or transmit PDUs on two (or more) access networks (i.e., transition to the active state). Each trigger set indicates a group or set of trigger conditions that the WTRU and UPF can monitor to make a state change (e.g., whether to transition). Dynamic replication means that only selected PDUs of the SDF are replicated across both accesses. The selection of these PDUs is based on trigger conditions, also called replication criteria. In the active state, the WTRU and UPF use the replication criteria to determine that a PDU should be replicated on two (or more) access networks. In the inactive state, the WTRU and UPF use the replication criteria to determine that a PDU should not be replicated on two (or more) access networks. In the inactive state, the replication criteria may also determine which single access to use (3GPP or non-3GPP).

[0116] The following procedures may be applied by an ATSSS-capable WTRU and a 5GC network. The WTRU may determine whether ATSSS is supported by the network based on a multi-access PDU session support indicator that may be provided by the AMF during the registration procedure, for example, as specified in 3GPP Section 4.22.9.1: Technical Specification Group Services and System Aspects; Procedures for 5G Systems (5GS); Stage 2, (Release 17), 3GPP 23.502 v17.3.0. If both the WTRU and the 5GC are ATSSS-capable, the network may decide to enable or disable the redundancy steering mode. If available, the network may further decide whether to use static or dynamic replication.

[0117] 4 is a flow diagram illustrating a redundancy steering mode operation according to various embodiments. The redundancy steering mode operation illustrated in FIG. 4 may be suitable as a procedure in the WTRU and UPF for the redundancy steering mode. Of note in this procedure are: 1) a reference to the extended PDU session establishment procedure, 2) rules for configuring various options for the redundancy steering mode (e.g., static vs. dynamic), 3) different states of the dynamic redundancy steering mode (e.g., active and inactive), and 4) new monitoring and triggering events for moving from different states of the dynamic redundancy steering mode.

[0118] With reference to Figure 4, the WTRU may perform an extended PDU session establishment procedure (400), as described in further detail below with reference to Figure 5. The WTRU may configure measurements (408) to support the redundancy steering mode, and may generate, receive, and / or determine uplink data to be transmitted at the WTRU (410). The WTRU may determine (412) whether the uplink data matches an SDF subject to the redundancy steering mode, and if not, may forgo traffic steering and transmit the uplink data (without applying steering). If the WTRU determines (412) that the uplink data matches an SDF subject to the redundancy steering mode, the WTRU may determine (402A) whether to perform static or dynamic redundancy steering according to a rule. If the WTRU determines to perform static redundancy steering according to the rules (e.g., if required by the rules 402A), the WTRU may transmit one or more PDUs of uplink data over two (or more) access networks; alternatively, if the WTRU determines to perform dynamic redundancy steering according to the rules (e.g., if required by the rules 402A), the WTRU may determine whether a dynamic redundancy steering mode is in an active state according to the rules 402B.

[0119] If the WTRU determines that dynamic redundancy steering is in an active state (402B), the WTRU may monitor a first set of triggers (406A) and may determine whether to change to an inactive state (416A). If the WTRU determines not to change state (416A), the WTRU may transmit one or more PDUs of uplink data over two (or more) access networks (404A) and the process may return to (410). If the WTRU determines to change state (416A), the WTRU may transmit one or more PDUs of uplink data over the selected access (404B) and the process may return to (410).

[0120] If the WTRU determines that the redundancy steering is not in an active state (402B), the WTRU may monitor a second set of triggers (406B) and may determine whether to change to an active state (416B). If the WTRU determines not to change state (416B), the WTRU may transmit one or more PDUs of uplink data via the selected access network (404B) and the process may return to (410). If the WTRU determines to change state (416B), the WTRU may transmit one or more PDUs of uplink data via two (or more) access networks (404B) and the process may return to (410).

[0121] 4 and the accompanying description above apply when a change to the state of the redundancy steering mode (e.g., made by the WTRU) occurs at a PDU transmission opportunity. Alternatively, the state transition may also occur at a non-PDU transmission opportunity. For example, the WTRU may continuously, continually, or repeatedly monitor the triggering set (or duplication criteria) and may change the state of the dynamic redundancy steering mode from duplication to no duplication and vice versa when one or more trigger conditions are met.

[0122] Representative PDU session establishment extended for redundant steering mode During the establishment of a multi-access PDU session (see (400) in FIG. 4), the WTRU may send a PDU session establishment request to the AMF via an access network (e.g., a 3GPP access network or a non-3GPP access network). In a network that does not support ATSSS, the WTRU may not be allowed to initiate (i) a procedure for establishing a multi-access PDU session, (ii) a procedure for establishing a PDU session with a "multi-access PDU network upgrade allowed" indication, (iii) a procedure for adding user plane resources on one access network to an existing multi-access PDU session established on another access network in a different mobile network, or (iv) a procedure for performing a PDU session modification with a request type of "multi-access PDU request" or with a "multi-access PDU network upgrade allowed" indication after moving from an evolved packet core (EPC) to a 5GC.

[0123] 5 is a signaling diagram illustrating an example extended PDU session establishment for supporting a redundancy steering mode according to one or more embodiments. At least a portion of the extended PDU session establishment illustrated in FIG. 5 may be suitable for implementing the extended PDU session establishment procedure (400) of FIG. 4. The exchange of ATSSS capabilities for the redundancy traffic steering mode and ATSSS rules for the redundancy traffic steering mode may be applied to the PDU session modification procedure.

[0124] Referring to FIG. 5, the WTRU may transmit information related to establishing a PDU session ("PDU session establishment information") to the network (AMF and SMF) (501). The PDU session establishment information may include information indicating a request to establish a PDU session ("PDU session establishment request information") and information indicating the WTRU's ATSSS capability for redundant traffic steering. In various embodiments, the PDU session establishment information may be, for example, a PDU session establishment request message including information indicating the WTRU's ATSSS capability for redundant traffic steering. The WTRU may generate a PDU session establishment request message (e.g., according to a specific protocol) and may include the WTRU's ATSSS capability for redundant traffic steering in such a message. As part of the PDU session establishment, the WTRU provides the ATSSS capability to the AMF. To enable the redundant steering mode, the WTRU may include one or more of the following as part of the capabilities: (i) information indicating support for one or more redundant traffic steering modes, (ii) information indicating support for a static redundant traffic steering mode, (iii) information indicating support for a dynamic redundant traffic steering mode, (iv) information indicating support for a redundant traffic steering mode over MPTCP, (v) information indicating support for a redundant traffic steering mode over ATSSS-LL, and (vi) information indicating support for duplicate detection.

[0125] The information indicating support for the redundant traffic steering mode may be an indication of whether the redundant traffic steering mode is supported by the WTRU.

[0126] The information indicating support for the static redundancy traffic steering mode may be an indication of whether the static redundancy traffic steering mode is supported by the WTRU (e.g., the indication provided is one of a first indication that the static redundancy traffic steering mode is supported by the WTRU and a second indication that the static redundancy traffic steering mode is not supported by the WTRU). Alternatively, the information indicating support for the static redundancy traffic steering mode may be an indication that the static redundancy traffic steering mode is supported by the WTRU (e.g., an indication is provided if the static redundancy traffic steering mode is supported by the WTRU and no indication is provided if the WTRU does not support the static redundancy traffic steering mode). A static redundancy traffic steering mode supported by the WTRU implies that the WTRU supports the redundant traffic steering mode. The information indicating support for the static redundancy traffic steering mode may be provided in addition to, instead of, only when, and / or independently of the information indicating support for the redundant traffic steering mode being provided.

[0127] The information indicating support for the dynamic redundancy traffic steering mode may be an indication of whether the dynamic redundancy traffic steering mode is supported by the WTRU (e.g., the indication provided is one of a first indication that the dynamic redundancy traffic steering mode is supported by the WTRU and a second indication that the dynamic redundancy traffic steering mode is not supported by the WTRU). Alternatively, the information indicating support for the dynamic redundancy traffic steering mode may be an indication that the dynamic redundancy traffic steering mode is supported by the WTRU (e.g., an indication is provided if the WTRU supports the dynamic redundancy traffic steering mode and no indication is provided if the WTRU does not support the dynamic redundancy traffic steering mode). A dynamic redundancy traffic steering mode supported by the WTRU implies that the WTRU supports the redundant traffic steering mode. The information indicating support for the dynamic redundancy traffic steering mode may be provided in addition to, instead of, only if, and / or independently of the information indicating support for the redundant traffic steering mode being provided).

[0128] The information indicating support for redundant traffic steering mode over MPTCP may be an indication of whether the redundant traffic steering mode over MPTCP is supported by the WTRU (e.g., the indication provided is one of a first indication that the redundant traffic steering mode over MPTCP is supported by the WTRU and a second indication that the redundant traffic steering mode over MPTCP is not supported by the WTRU). Alternatively, the information indicating support for redundant traffic steering mode over MPTCP may be an indication that the redundant traffic steering mode over MPTCP is supported by the WTRU (e.g., an indication is provided if the WTRU supports steering function in MPTCP, and no indication is provided if the WTRU does not support redundant traffic steering mode over MPTCP). A redundant traffic steering mode over MPTCP supported by the WTRU implies that the WTRU supports the redundant traffic steering mode. The information indicating support for redundant traffic steering mode over MPTCP may be provided in addition to, instead of, only when, and / or independently of the information indicating support for redundant traffic steering mode being provided.

[0129] The information indicating support of the redundant traffic steering mode on the ATSSS-LL may be an indication of whether the redundant traffic steering mode on the ATSSS-LL is supported by the WTRU (e.g., the indication provided is one of a first indication that the redundant traffic steering mode on the ATSSS-LL is supported by the WTRU and a second indication that the redundant traffic steering mode on the ATSSS-LL is not supported by the WTRU). Alternatively, the information indicating support of the redundant traffic steering mode on the ATSSS-LL may be an indication that the redundant traffic steering mode on the ATSSS-LL is supported by the WTRU (e.g., the indication is provided if the WTRU supports the steering function in the ATSSS-LL and no indication is provided if the WTRU does not support the redundant traffic steering mode on the ATSSS-LL). Support of the redundant traffic steering mode on the ATSSS-LL by the WTRU implies that the WTRU supports the redundant traffic steering mode. The information indicating support of the redundant traffic steering mode on the ATSSS-LL may be provided in addition to, instead of, only when, and / or independently of the information indicating support of the redundant traffic steering mode being provided.

[0130] The information indicating support for duplicate detection may be an indication of whether duplicate detection and discarding functionality is supported by the WTRU (e.g., the indication provided is one of a first indication that duplicate detection and discarding functionality is supported by the WTRU and a second indication that duplicate detection and discarding functionality is not supported by the WTRU). Alternatively, the information indicating support for duplicate detection and discarding functionality may be an indication that duplicate detection and discarding functionality is supported by the WTRU (e.g., an indication is provided if the WTRU supports duplicate detection and discarding functionality and no indication is provided if the WTRU does not support duplicate detection and discarding functionality). The information indicating support for duplicate detection and discarding functionality may be provided in addition to, instead of, only if, and / or independently of information indicating support for redundant traffic steering mode on the ATSSS-LL. The information indicating support for duplicate detection and discarding functionality may be provided in addition to, instead of, only if, and / or independently of information indicating support for redundant traffic steering mode being provided.

[0131] Although not shown, support for redundant traffic steering modes may be indicated across any number of steering functions.

[0132] The SMF may interact with the PCF to obtain PCC rules for the redundant steering mode (502-503), for example based on the ATSSS capabilities. The SMF may determine ATSSS rules for the redundant steering mode, N4 rules for the redundant steering mode, and any measurement assistance information for redundant steering (504), for example based on the PCC rules for the redundant steering mode. The ATSSS rules and N4 rules may include and / or indicate information specific to (related to) the redundant steering mode. The information specific to (related to) the redundancy steering mode may include, for example, (i) an identifier of the SDF ("SDF identifier"), (ii) a priority of the redundancy steering mode, (iii) information indicating whether the redundancy steering mode applies to the uplink or downlink or both the uplink and downlink, (iv) information indicating whether the redundancy steering mode is a static redundancy steering mode or a dynamic redundancy steering mode, (v) information indicating whether an initial or primary state of the dynamic steering mode is active or inactive, (vi) information indicating whether the access network (e.g., a 3GPP access network or a non-3GPP access network) initial PDU transmission of the SDF is terminated or should be terminated if the dynamic steering mode is in an inactive state, (vii) information indicating whether or not (or that) implementation of duplication detection and discarding is mandatory for the ATSSS-LL steering function, (viii) information indicating a default or fallback steering mode to use when traffic duplication is not required (e.g., in a scenario where the requirements of the SDF can be met using both 3GPP legs and non-3GPP legs), and (ix) information indicating a measurement configuration to support the redundancy steering mode.

[0133] In various embodiments, the information indicating the measurement configuration to support the redundancy steering mode may include configuration details for the PMF, thresholds for triggering the redundancy steering mode state transition, configuration details for new performance metrics, etc.

[0134] In some cases, the redundancy steering mode for the WTRU-to-UPF portion of the uplink path ("WTRU-to-UPF path") may be different from the UPF-to-WTRU portion of the downlink path ("UPF-to-WTRU path"). This may occur when the 3GPP leg uses frequency division duplexing and the uplink and downlink are on different spectrums. In such cases, the performance metrics for the 3GPP leg may be different for the uplink and downlink, and as a result, the replication state may not necessarily be the same for uplink and downlink transmissions. To account for this, the ATSSS and N4 rules may have separate information for the uplink and downlink.

[0135] Although not shown, the SMF can check the Unified Data Manager (UDM) to determine whether the redundancy steering mode is allowed by the subscription or, for example, in a home routing scenario. The SMF can assign QoS profiles to the access networks. In Release 17, for a GBR QoS flow, the SMF provides a QoS profile to a single access network. If the PCC rules allow the GBR QoS flow in both access networks, the SMF decides, based on its local policy, which of the access networks provides the QoS profile for the GBR QoS flow. When the redundancy steering mode is supported for the GBR QoS flow, the SMF can provide the QoS profile to both access networks.

[0136] The SMF may send information related to the establishment and / or modification of an N4 session ("N4 session establishment / modification information") to the UPF (505). The N4 session establishment / modification information may include information indicating a request for establishment / modification of an N4 session ("N4 session establishment / modification request information") and information indicating an N4 rule and measurement assistance information. In various embodiments, the N4 session establishment / modification information may be, for example, an N4 session establishment / modification request message including information indicating the N4 rule and the measurement assistance information. The SMF may generate an N4 session establishment / modification request message (e.g., according to a particular protocol) and may include information indicating the N4 rule and the measurement assistance information in such a message.

[0137] The UPF may receive (505) the N4 session establishment modification information and may determine and / or configure the N4 rule based on the information indicative of the N4 rule. The UPF may enable or disable the redundancy steering mode based on the N4 session establishment modification information (e.g., the N4 rule determined from the N4 session establishment modification information). The UPF may apply one or more of the N4 rules, for example, if the redundancy steering mode is enabled. The UPF may apply one or more of the N4 rules, for example, to determine the details of the redundancy steering mode. As an example, the UPF may determine that the replication may be one of static and dynamic, for example, based on a first rule of the N4 rules specifying that the replication is either static or dynamic. If determined to be dynamic, the UPF may determine that the initial state of the replication may be one of active and inactive, for example, based on a second rule of the N4 rules specifying that the replication state is either initially active or initially inactive. If determined to be inactive, the UPF may determine that the primary leg and / or the initial leg is one of a 3GPP leg and a non-3GPP leg, for example, based on a third rule of the N4 rules that specifies that the primary leg and / or the initial leg is either a 3GPP leg or a non-3GPP leg.

[0138] The UPF may send N4 session establishment / modification information to the SMF (506). The N4 session establishment / modification information may include information indicating a response to the N4 session establishment / modification request information ("N4 session establishment / modification response information"). In various embodiments, the N4 session establishment modification information may be, for example, an N4 session establishment / modification response message. The SMF may generate the N4 session establishment / modification response message (e.g., according to a particular protocol).

[0139] The SMF may receive N4 session establishment / modification information from the UPF (506). The SMF may transmit PDU session establishment information to the WTRU (507). The PDU session establishment information may include information indicating acceptance of the PDU session establishment ("PDU session establishment accept information") and information indicating the ATSSS rule and the measurement assistance information. In various embodiments, the PDU session establishment information may be, for example, a PDU session establishment accept message including information indicating the ATSSS rule and the measurement assistance information. The SMF may generate a PDU session establishment accept message (e.g., according to a particular protocol) and may include the information indicating the ATSSS rule and the measurement assistance information in such a message.

[0140] The WTRU may receive PDU session establishment information from the SMF (507) and may determine and / or configure the ATSSS rule based on the information indicating the ATSSS rule. The WTRU may enable or disable the redundancy steering mode based on the PDU session establishment information (e.g., the ATSSS rule determined from the PDU session establishment acceptance information). The WTRU may apply one or more of the ATSSS rules, for example, if the redundancy steering mode is enabled. The WTRU may apply one or more of the ATSSS rules to determine the details of the redundancy steering mode. As an example, the WTRU may determine that the duplication may be one of static and dynamic, for example, based on a first rule of the ATSSS rules specifying that the duplication is either static or dynamic. If determined to be dynamic, the WTRU may determine that the initial state of the duplication may be one of active and inactive, for example, based on a second rule of the ATSSS rules specifying that the duplication state is either initially active or initially inactive. If determined to be inactive, the WTRU may determine that the primary and / or initial leg is one of a 3GPP leg and a non-3GPP leg, for example, based on a third rule of the ATSSS rules that specifies that the primary and / or initial leg is a 3GPP leg or a non-3GPP leg.

[0141] During normal operation, the WTRU and UPF may follow the configured ATSSS and N4 rules, respectively. If the redundancy steering mode is enabled and dynamic, the WTRU and UPF may monitor triggers (based on measurements or events) to determine the duplication state. If the ATSSS rules (or N4 rules) specify that the WTRU (or UPF) does not need to perform duplication detection and discarding, the WTRU (or UPF) assumes that this function is handled by a higher layer (e.g., an application).

[0142] Typical Dynamic Redundancy Steering Mode The dynamic redundancy steering mode may occur when the redundancy steering mode is enabled. The WTRU and UPF may use a duplication criterion to determine whether duplication is active or inactive. To enable dynamic switching between active and inactive, the WTRU and UPF may require and / or use performance measurements for each access network. The measurements may be configured, for example, according to (408) of FIG. 4 and the accompanying disclosure. The WTRU and UPF may perform one or more of the following measurements: (i) one or more PLR ​​measurements, (ii) one or more delay measurements, (iii) one or more variabilities of delay measurements, and (iv) one or more load measurements.

[0143] The PLR ​​measurement for each access network may be the PDU packet loss rate for the corresponding access network. Separate measurements may be made for uplink and downlink transmissions.

[0144] The delay measurement for each access network may be some measure of delay for the corresponding access network, such as, for example, a round trip delay or one-way delay for the corresponding access network. The one-way delay may be measured from the WTRU to the UPF or from the UPF to the WTRU. Separate measurements may be made for uplink and downlink transmissions. The delay measurement may be denoted herein as the term "D." Alternatively, the delay measurement for each access network may be the measured round trip delay for the corresponding access network or the average (mean) of the measured one-way delay for the corresponding access network.

[0145] The variability of the delay measurement for each access network may be a measure of the variability of packet transmissions on the corresponding access network, such as, for example, the variability of round trip delay or one-way delay for the corresponding access network. The variability measurement may come from different radio scheduling mechanisms used for 3GPP and non-3GPP access networks, and / or different transport paths in the core network that may be used by 3GPP RAN nodes and non-3GPP interworking nodes (Non-3GPP Interworking Function (N3IWF), Trusted Non-3GPP Gateway Function (TNGF), Trusted WLAN Interworking Function (TWIF), Wireline Access Gateway Function (W-AGF)). Separate measurements may be made for uplink and downlink transmissions. The variability measurement may be any of the following: statistical variance of delay, statistical standard deviation of delay, median delay, k-th percentile of delay, maximum observed delay, minimum observed delay, etc. The variability of the delay measurement may be denoted herein as the term "VAR".

[0146] The load measurement for each access network may be a measurement of the load on the corresponding access network, such as, for example, radio load, transport network load (load in the core network from the RAN to UPF / UPF to UPF (N3 / N9) interface to UPF), and a combination of radio load and transport network load measurements. Separate measurements can be made for the uplink and downlink. The load measurements may be denoted herein as the term "L".

[0147] The PLR, delay, and variability of delay measurements may be direction specific. For the WTRU, the measurements may be based on the uplink path (WTRU to UPF), and / or for the UPF, the measurements may be based on the downlink path (UPF to WTRU). In the following, measurements for an access network may be differentiated by underlining. For example, a PLR measurement of a first access may be denoted as PLR_1, and a delay measurement of a second access may be denoted as D_2. Various thresholds for PLR measurements (e.g., PLR_thresholdA_1, PLR_thresholdA_2, PLR_thresholdB_1, PLR_thresholdB_2, PLR_thresholdC_1, PLR_thresholdC_2, etc.) are referenced in the following disclosure. These thresholds may be configured and / or set by the network and may be configured to be set to the same or different values. The same applies to the various thresholds for the delay measure (D), the variability of the delay measure (VAR), and the load measure (L) mentioned in the following disclosure.

[0148] Representative active to inactive transitions A state transition of the dynamic redundancy steering mode from an active state to an inactive state may occur, be triggered, and / or be performed based on one or more of a variety of measurements, such as any of the measurements disclosed above. By way of example, the WTRU and / or the UPF may trigger and / or perform a state transition of the dynamic redundancy steering mode from an active state to an inactive state based on one or more of a variety of measurements, such as according to (416A) and / or (416B) of FIG. 4 and the accompanying disclosure.

[0149] In various embodiments, the state transition of the dynamic redundancy steering mode from the active state to the non - active state may occur, be triggered, and / or be executed in response to, based on, and / or in relation to any one or combination of various conditions that occur. The various conditions are, for example, (i) a packet loss ratio (PLR) measurement for a first access network that meets (e.g., is below) a corresponding first PLR threshold of one or more PLR thresholds (represented herein as "PLR_1 < PLR_thresholdA_1"); (ii) a PLR measurement for a second access network that meets (e.g., is below) a corresponding second threshold of one or more PLR thresholds (represented herein as "PLR_2 < PLR_thresholdA_2"); (iii) a delay measurement for a first access network that meets (e.g., is below) a corresponding first delay threshold of one or more delay thresholds (represented herein as "D_1 < D_thresholdA_1"); (iv) a delay measurement for a second access network that meets (e.g., is below) a corresponding second delay threshold of one or more delay thresholds (represented herein as "D_2 < D_thresholdA_2"); (v) the variability of delay measurements for a first access network that meets (e.g., is below) a corresponding first variability of one or more variability of delay thresholds (represented herein as "VAR_1 < VAR_thresholdA_1"); (vi) the variability of delay measurements for a second access network that meets (e.g., is below) a corresponding second variability of one or more variability of delay thresholds (represented herein as "VAR_2 < VAR_thresholdA_2"); (vii) a load measurement for a first access network that meets (e.g., is above) a corresponding first load threshold of one or more load thresholds (represented herein as "L_1 > L_thresholdA_1"); (viii) a load measurement for a second access network that meets (e.g., is above) a corresponding second load threshold of one or more load thresholds (represented herein as "L_2 > L_thresholdA_2").(ix) The PLR measurement value for the first access network that meets (e.g., is greater than) the corresponding third PLR threshold among the one or more PLR thresholds (represented as "PLR_1 > PLR_thresholdB_1" in this specification); (x) The PLR measurement value for the second access network that meets (e.g., is greater than) the corresponding fourth PLR threshold among the one or more PLR thresholds (represented as "PLR_2 > PLR_thresholdB_2" in this specification); (xi) The delay measurement value for the first access network that meets (e.g., is greater than) the corresponding third delay threshold among the one or more delay thresholds (represented as "D_1 > D_thresholdB_1" in this specification); (xii) The delay measurement value for the second access network that meets (e.g., is greater than) the corresponding fourth delay threshold among the one or more delay thresholds (represented as "D_2 > D_thresholdB_2" in this specification); (xiii) The variability of the delay measurement value for the first access network that meets (e.g., is greater than) the corresponding third variability among the one or more variabilities of the delay threshold (represented as "VAR_1 > VAR_thresholdB_1" in this specification); (xiv) The variability of the delay measurement value for the second access network that meets (e.g., is greater than) the corresponding fourth variability among the one or more variabilities of the delay threshold (represented as "VAR_2 > VAR_thresholdB_2" in this specification); (xv) The load measurement value for the first access network that meets (e.g., is less than) the corresponding third load threshold among the one or more load thresholds (represented as "L_1 < L_thresholdB_1" in this specification); and (xvi) May include the load measurement value for the second access network that meets (e.g., is less than) the corresponding fourth load threshold among the one or more load thresholds (represented as "L_2 < L_thresholdA_2" in this specification).;

[0150] The condition PLR_1 < PLR_thresholdA_1, when satisfied, may indicate that the first access network can meet the SDF requirements (e.g., for a significant amount of time), alone or in combination with one or more other satisfied and / or unsatisfied conditions, that there may be no need for redundant transmission via the second access network (e.g., an indication). The WTRU and / or UPF can trigger and / or execute a state transition in the dynamic redundant steering mode from the active state to the inactive state based on the condition PLR_1 < PLR_thresholdA_1 being satisfied (e.g., alone or in combination with one or more other conditions being satisfied and / or not satisfied).

[0151] The condition PLR_2 < PLR_thresholdA_2, when satisfied, may indicate that the second access network can meet the SDF requirements (e.g., for a significant amount of time), alone or in combination with one or more other satisfied and / or unsatisfied conditions, that there may be no need for redundant transmission via the first access network (e.g., an indication). The WTRU and / or UPF can trigger and / or execute a state transition in the dynamic redundant steering mode from the active state to the inactive state based on the condition PLR_2 < PLR_thresholdA_2 being satisfied (e.g., alone or in combination with one or more other conditions being satisfied and / or not satisfied). PLR_thresholdA_2 and PLR_thresholdA_1 can each have values specific to the second access network and the first access network, respectively, and these values may be the same or different.

[0152] When the condition D_1 < D_thresholdA_1 is met, there is a possibility that the first access network can meet the SDF requirements (e.g., for a significant amount of time), and it can be shown (e.g., as an indication) that it may eliminate the need for redundant transmission via a second access, either alone or in combination with one or more other met and / or unmet conditions. The WTRU and / or UPF can trigger and / or execute a state transition of the dynamic redundant steering mode from the active state to the inactive state based on the condition D_1 < D_thresholdA_1 being met (e.g., alone or in combination with one or more other conditions being met and / or not met).

[0153] When the condition D_2 < D_thresholdA_2 is met, there is a possibility that the second access network can meet the SDF requirements (e.g., for a significant amount of time), and it can be shown (e.g., as an indication) that it may eliminate the need for redundant transmission via the first access network, either alone or in combination with one or more other met and / or unmet conditions. The WTRU and / or UPF can trigger and / or execute a state transition of the dynamic redundant steering mode from the active state to the inactive state based on the condition D_2 < D_thresholdA_2 being met (e.g., alone or in combination with one or more other conditions being met and / or not met). D_thresholdA_2 and D_thresholdA_1 can have values specific to the second access network and the first access network, respectively, and these values may be the same or different.

[0154] When the condition VAR_1 < VAR_thresholdA_1 is met, it may indicate that the first access network can meet the SDF requirements (e.g., for a significant amount of time), alone or in combination with one or more other met and / or unmet conditions, it may be possible to eliminate the need for redundant transmission via the second access network (e.g., an indication). The WTRU and / or UPF can trigger and / or execute a state transition of the dynamic redundant steering mode from the active state to the inactive state based on the condition VAR_1 < VAR_thresholdA_1 being met (e.g., alone or in combination with one or more other conditions being met and / or not met).

[0155] When the condition VAR_2 < VAR_thresholdA_2 is met, it may indicate that the second access network can meet the SDF requirements (e.g., for a significant amount of time), alone or in combination with one or more other met and / or unmet conditions, it may be possible to eliminate the need for redundant transmission via the first access network (e.g., an indication). The WTRU and / or UPF can trigger and / or execute a state transition of the dynamic redundant steering mode from the active state to the inactive state based on the condition VAR_2 < VAR_thresholdA_2 being met (e.g., alone or in combination with one or more other conditions being met and / or not met). VAR_thresholdA_2 and VAR_thresholdA_1 can each have values specific to the second access network and the first access network, respectively, and these values may be the same or different.

[0156] The condition L_1>L_thresholdA_1, when met, may indicate (e.g., be an indication) that traffic of the SDF should be removed from the first access network. The WTRU and / or UPF may trigger and / or perform a state transition of the dynamic redundancy steering mode from an active state to an inactive state based on the condition L_1>L_thresholdA_1 being met (e.g., alone or in combination with one or more other conditions being met and / or not being met).

[0157] The condition L_2>L_thresholdA_2, when met, may indicate (e.g., is an indication) that traffic of the SDF should be removed from the second access network. The WTRU and / or UPF may trigger and / or perform a state transition of the dynamic redundancy steering mode from an active state to an inactive state based on the condition L_2>L_thresholdA_2 being met (e.g., alone or in combination with one or more other conditions being met and / or not being met). L_thresholdA_2 and L_thresholdA_1 may have values ​​specific to the second access network and the first access network, respectively, and these values ​​may be the same or different.

[0158] The condition PLR_1>PLR_thresholdB_1, when met, may indicate (e.g., be an indication) that redundant transmissions over the first access network do not meet the requirements of the SDF (e.g., for a significant amount of time) and, either alone or in combination with one or more other met and / or unmet conditions, may obviate the need for redundant transmissions over the first access network. The WTRU and / or UPF may trigger and / or perform a state transition of the dynamic redundancy steering mode from an active state to an inactive state based on the condition PLR_1>PLR_thresholdB_1 being met (e.g., alone or in combination with one or more other conditions being met and / or not met).

[0159] The condition PLR_2>PLR_thresholdB_2, when met, may indicate (e.g., be an indication) that redundant transmissions over the second access network do not meet the requirements of the SDF (e.g., for a significant amount of time), potentially obviating the need for redundant transmissions over the second access network, either alone or in combination with one or more other met and / or unmet conditions. The WTRU and / or UPF may trigger and / or perform a state transition of the dynamic redundancy steering mode from an active state to an inactive state based on the condition PLR_2>PLR_thresholdB_2 being met (e.g., alone or in combination with one or more other conditions being met and / or unmet). PLR_thresholdB_2 and PLR_thresholdB_1 may have values ​​specific to the second access network and the first access network, respectively, and these values ​​may be the same or different.

[0160] The condition D_1>D_thresholdB_1, when met, may indicate (e.g., be an indication) that redundant transmissions over the first access network do not meet the requirements of the SDF (e.g., for a significant amount of time) and, either alone or in combination with one or more other met and / or unmet conditions, may obviate the need for redundant transmissions over the first access network. The WTRU and / or UPF may trigger and / or perform a state transition of the dynamic redundancy steering mode from an active state to an inactive state based on the condition D_1>D_thresholdB_1 being met (e.g., alone or in combination with one or more other conditions being met and / or not met).

[0161] The condition D_2>D_thresholdB_2, when met, may indicate (e.g., be an indication) that redundant transmissions over the second access network do not meet the requirements of the SDF (e.g., for a significant amount of time), potentially obviating the need for redundant transmissions over the second access network, either alone or in combination with one or more other met and / or unmet conditions. The WTRU and / or UPF may trigger and / or perform a state transition of the dynamic redundancy steering mode from an active state to an inactive state based on the condition D_2>D_thresholdB_2 being met (e.g., alone or in combination with one or more other conditions being met and / or unmet). D_thresholdB_2 and D_thresholdB_1 may have values ​​specific to the second access network and the first access network, respectively, and these values ​​may be the same or different.

[0162] The condition VAR_1>VAR_thresholdB_1, when met, may indicate (e.g., be an indication) that redundant transmissions over the first access network do not meet the requirements of the SDF (e.g., for a significant amount of time) and, either alone or in combination with one or more other met and / or unmet conditions, may obviate the need for redundant transmissions over the first access network. The WTRU and / or UPF may trigger and / or perform a state transition of the dynamic redundancy steering mode from an active state to an inactive state based on the condition VAR_1>VAR_thresholdB_1 being met (e.g., alone or in combination with one or more other conditions being met and / or not met).

[0163] The condition VAR_2>VAR_thresholdB_2, when met, may indicate (e.g., be an indication) that redundant transmissions over the second access network do not meet the requirements of the SDF (e.g., for a significant amount of time), potentially obviating the need for redundant transmissions over the second access network, either alone or in combination with one or more other met and / or unmet conditions. The WTRU and / or UPF may trigger and / or perform a state transition of the dynamic redundancy steering mode from an active state to an inactive state based on the condition VAR_2>VAR_thresholdB_2 being met (e.g., alone or in combination with one or more other conditions being met and / or unmet). VAR_thresholdB_2 and VAR_thresholdB_1 may have values ​​specific to the second access network and the first access network, respectively, and these values ​​may be the same or different.

[0164] The condition L_1 < L_thresholdB_1, when satisfied, may indicate (e.g., an indication) that there is no harm in leaving redundant transmissions via the first access network. The WTRU and / or UPF may not trigger and / or execute a state transition to the dynamic redundant steering mode from the active state based on the condition L_1 < L_thresholdB_1 being satisfied (e.g., alone or in combination with one or more other conditions being satisfied and / or not satisfied).

[0165] The condition L_2 < L_thresholdB_2, when satisfied, may indicate (e.g., an indication) that there is no harm in leaving redundant transmissions via the second access network. The WTRU and / or UPF may not trigger and / or execute a state transition to the dynamic redundant steering mode from the active state based on the condition L_1 < L_thresholdB_1 being satisfied (e.g., alone or in combination with one or more other conditions being satisfied and / or not satisfied).

[0166] Transitioning the redundant steering mode to inactive may be based on the first link meeting the SDF requirements. Hereinafter, it is assumed that the SDF has requirements regarding loss, delay, and variability, but it should be understood that these requirements may include any subset of the loss, delay, and variability requirements. For example, the SDF may have only a loss requirement, or the SDF may have loss and delay requirements. In addition to the SDF requirements, the transition may be affected by the load state of the second link.

[0167] For example, the WTRU and / or UPF may trigger and / or perform a state transition to an inactive state of the redundancy steering mode in response to, based on, and / or in association with one of the links meeting the loss, delay, and variability requirements of the SDF. The WTRU and / or UPF may trigger and / or perform the state transition by, for example, satisfying a first trigger condition ("Trigger 1"). Trigger 1 may be as follows: Trigger 1: (PLR_1 <PLR_thresholdA_1)AND(D_1<D_thresholdA_1)AND(VAR_1<VAR_thresholdA_1)

[0168] As a second example, the WTRU and / or UPF may trigger and / or perform a state transition to an inactive state of the redundancy steering mode in response to, based on, and / or in relation to one of the links meeting the loss, delay, and variability requirements of the SDF and the other link being congested. The WTRU and / or UPF may trigger and / or perform the state transition by, for example, meeting a second trigger condition ("Trigger 2"). Trigger 2 may be as follows: Trigger 2: (PLR_1 <PLR_thresholdA_1)AND(D_1<D_thresholdA_1)AND(VAR_1<VAR_thresholdA_1)AND(L_2> L_thresholdB_2)

[0169] As a third example, the WTRU and / or UPF may trigger and / or perform a state transition to an inactive state of the redundant steering mode when there is no benefit in having a duplicate. This may occur when the quality of both links is insufficient and even with the duplicate, the system cannot meet the loss, delay, and / or variability requirements of the SDF. The WTRU and / or UPF may trigger and / or perform a state transition, for example, by satisfying a third trigger condition ("Trigger 3"). Trigger 3 may be as follows: Trigger 3:((PLR_1>PLR_thresholdB_1)OR(D_1>D_thresholdB_1)OR(VAR_1>VAR_thresholdB_1))AND((PLR_2>PLR_thresholdB_2)OR(D_2>D_thresholdB_2)OR(VAR_2>VAR_thresholdB_2))

[0170] The WTRU and / or UPF may (e.g., may need to) stop using one of the legs in response to, based on, and / or in conjunction with the transition to the inactive replication state. As described, the WTRU and / or UPF may select the leg that meets the requirements of the SDF. If both legs can meet the requirements of the SDF, the WTRU may select one leg for operation. Various options are possible for making this selection.

[0171] In a first option, the WTRU may randomly select between the two legs. In a second option, the WTRU may select the leg configured as the primary or initial leg. In a third option, the WTRU may select the leg based on some preconfigured rule (e.g., always select 3GPP or always select non-3GPP). In a fourth option, the WTRU may select the leg based on some non-performance metric. For example, the WTRU may select based on WTRU power status, user performance, etc. In a fifth option, the WTRU may select the leg based on a default or fallback steering mode. For example, the WTRU may fall back to active-standby if both legs can meet the requirements of the SDF.

[0172] Typical inactive to active transition A state transition of the dynamic redundancy steering mode from an inactive state to an active state may occur, be triggered, and / or be performed based on one or more of a variety of measurements, such as any of the measurements disclosed above. By way of example, the WTRU and / or the UPF may trigger and / or perform a state transition of the dynamic redundancy steering mode from an active state to an inactive state based on one or more of a variety of measurements, such as per (416B) of FIG. 4 and the accompanying disclosure.

[0173] In various embodiments, the state transition of the dynamic redundancy steering mode from the active state to the inactive state may occur, be triggered, and / or be performed in response to, based on, and / or in relation to any one or combination of various conditions occurring. In the following, it is assumed that the single access used for PDU transmission in the inactive state is a first access network. If the single access used for PDU transmission in the inactive state is a second access network, an equivalent set of conditions and triggers is applicable.

[0174] The various conditions can include, for example, (i) a PLR measurement value for a first access network that meets (e.g., is greater than) the corresponding fifth PLR threshold among one or more PLR thresholds (represented herein as "PLR_1 > PLR_thresholdB_3"); (ii) a delay measurement value for a first access network that meets (e.g., is greater than) the corresponding fifth delay threshold among one or more delay thresholds (represented herein as "D_1 > D_thresholdB_3"); (iii) the variability of the delay measurement values for a first access network that meets (e.g., is greater than) the corresponding fifth variability among one or more variabilities of the delay threshold (represented herein as "VAR_1 > VAR_thresholdB_3"); (iv) a PLR measurement value for a second access network that meets (e.g., is less than) the corresponding sixth threshold among one or more PLR thresholds (represented herein as "PLR_2 < PLR_thresholdC_1"); (v) a delay measurement value for a second access network that meets (e.g., is less than) the corresponding sixth delay threshold among one or more delay thresholds (represented herein as "D_2 < D_thresholdC_1"); (vi) the variability of the delay measurement for a second access network that meets (e.g., is less than) the corresponding sixth variability among one or more variabilities of the delay threshold (represented herein as "VAR_2 < VAR_thresholdC_1"); and (vii) a load measurement value for a second access network that meets (e.g., is less than) the corresponding fifth load threshold among one or more load thresholds (represented herein as "L_2 < L_thresholdB_3").

[0175] The condition PLR_1>PLR_thresholdB_3, when met, may indicate (e.g., is an indication) that transmissions on the first access network do not meet the requirements of the SDF (e.g., for a significant amount of time) and may indicate the need for redundant transmissions over the second access network, either alone or in combination with one or more other met and / or unmet conditions. The WTRU and / or UPF may trigger and / or perform a state transition of the dynamic redundancy steering mode from an inactive state to an active state based on the condition PLR_1>PLR_thresholdB_3 being met (e.g., alone or in combination with one or more other conditions being met and / or unmet). PLR_thresholdB_3 may have a value specific to the first access network, which may be the same or different from the values ​​of PLR_thresholdA_2, PLR_thresholdA_1, PLR_thresholdB_2, and PLR_thresholdB_1.

[0176] The condition D_1>D_thresholdB_3, when met, may indicate (e.g., be an indication) that transmissions on the first access network do not meet the requirements of the SDF and may, alone or in combination with one or more other met and / or unmet conditions, indicate the need for redundant transmissions over the second access network. The WTRU and / or UPF may trigger and / or perform a state transition of the dynamic redundancy steering mode from an inactive state to an active state based on the condition D_1>D_thresholdB_3 being met (e.g., alone or in combination with one or more other conditions being met and / or unmet). D_thresholdB_3 may have a value specific to the first access network, which may be the same or different from the values ​​of D_thresholdA_2, D_thresholdA_1, D_thresholdB_2, and D_thresholdB_1.

[0177] The condition VAR_1 > VAR_thresholdB_3, when satisfied, may indicate (e.g., an indication) that transmissions on the first access network do not meet the SDF requirements (e.g., for a significant amount of time), either alone or in combination with one or more other satisfied and / or unsatisfied conditions, the need for redundant transmissions via the second access network. The WTRU and / or UPF may trigger and / or execute a state transition to an active dynamic redundancy steering mode from an inactive state based on the condition VAR_1 > VAR_thresholdB_3 being satisfied (e.g., alone or in combination with one or more other conditions being satisfied and / or not satisfied). VAR_thresholdB_3 may have a value specific to the first access network, which value may be the same as or different from the values of VAR_thresholdA_2, VAR_thresholdA_1, VAR_thresholdB_2, and VAR_thresholdB_1.

[0178] The condition PLR_2 < PLR_thresholdC_1, when satisfied, may indicate (e.g., an indication) that deploying a duplicate (e.g., transmitting a duplicate PDU) via the second access network may help meet the SDF requirements. The WTRU and / or UPF may trigger and / or execute a state transition to an active dynamic redundancy steering mode from an inactive state based on the condition PLR_2 < PLR_thresholdC_1 being satisfied (e.g., alone or in combination with one or more other conditions being satisfied and / or not satisfied). PLR_thresholdC_1 may have a value specific to the second access network, which value may be the same as or different from the values of PLR_thresholdA_2, PLR_thresholdA_1, PLR_thresholdB_3, PLR_thresholdB_2, and PLR_thresholdB_1.

[0179] When the condition D_2 < D_thresholdC_1 is met, it can be shown (e.g., as an indication) that deploying the duplication (sending a duplicated PDU) via the second access network can help meet the requirements of the SDF. The WTRU and / or UPF can trigger and / or execute a state transition to the active state of the dynamic redundancy steering mode from the non-active state based on the condition D_2 < D_thresholdC_1 being met (e.g., alone or in combination with one or more other conditions being met and / or not met). D_thresholdC_1 may have a value specific to the second access network, and that value may be the same as or different from the values of D_thresholdA_2, D_thresholdA_1, D_thresholdB_3, D_thresholdB_2, and D_thresholdB_1.

[0180] When the condition VAR_2 < VAR_thresholdC_1 is met, it can be shown (e.g., as an indication) that deploying the duplication (e.g., sending a duplicated PDU) via the second access network can help meet the requirements of the SDF. The WTRU and / or UPF can trigger and / or execute a state transition to the active state of the dynamic redundancy steering mode from the non-active state based on the condition VAR_2 < VAR_thresholdC_1 being met (e.g., alone or in combination with one or more other conditions being met and / or not met). VAR_thresholdC_1 can have a value specific to the second access network, and that value may be the same as or different from the values of VAR_thresholdA_2, VAR_thresholdA_1, VAR_thresholdB_3, VAR_thresholdB_2, and VAR_thresholdB_1.

[0181] When the condition L_2 < L_thresholdB_3 is satisfied, it can indicate (e.g., be an indication) that the second access network is not congested and / or, alone or in combination with one or more other satisfied and / or unsatisfied conditions, can indicate that deploying a replica (e.g., sending a replicated PDU) on the second access network can help meet the requirements of the SDF. Since replication via the second access network may not significantly affect the load on the second access network, it may be harmless to send replicated PDUs via the second access if it can help meet the requirements of the SDF. The WTRU and / or UPF can trigger and / or execute a state transition to the active redundant steering mode from the non-active state based on the condition L_2 < L_thresholdB_3 being satisfied (e.g., alone or in combination with one or more other conditions being satisfied and / or not satisfied). L_thresholdB_3 may have a value specific to the first access network, and that value may be the same as or different from the values of L_thresholdA_2, L_thresholdA_1, L_thresholdB_2, and L_thresholdB_1. Transitioning the redundant steering mode to active may be based on the first link not meeting the requirements of the SDF. In the following, it is assumed that the SDF has requirements regarding loss, delay, and variability, but it should be understood that these requirements can include any subset of the loss, delay, and variability requirements. For example, the SDF may have only a loss requirement or the SDF may have loss and delay requirements. In addition to the SDF requirements, the transition may also be affected by the load state of the second link.

[0182] For example, the WTRU and / or UPF may trigger and / or perform a state transition to an active state of the redundancy steering mode in response to, based on, and / or in association with the first access link failing to meet a loss, delay, or variability requirement of the SDF. The WTRU and / or UPF may trigger and / or perform a state transition by, for example, satisfying a fourth trigger condition ("Trigger 4"). Trigger 4 may be as follows: Trigger 4: (PLR_1>PLR_thresholdB_3)OR(D_1>D_thresholdB_3)OR(VAR_1>VAR_thresholdB_3)

[0183] As a second example, the WTRU and / or UPF may trigger and / or perform a state transition to an active state of the redundancy steering mode in response to, based on, and / or in association with the first access link being unable to meet the loss, delay, or variability requirements of the SDF and the other link is not congested. The WTRU and / or UPF may trigger and / or perform a state transition in response to, based on, and / or in association with, for example, a fifth trigger condition ("Trigger 5") being satisfied. Trigger 5 may be as follows: Trigger 5:((PLR_1>PLR_thresholdB_3)OR(D_1>D_thresholdB_3)OR(VAR_1>VAR_thresholdB_3))AND(L_2 <L_thresholdB_3)

[0184] As a third example, the WTRU and / or UPF may trigger and / or perform a state transition to an active state of the redundancy steering mode in response to, based on, and / or in association with a transmission on the first access link not meeting the loss, delay, or variability requirements of the SDF and the quality of the second access network to enable use of the second access network to help meet the requirements of the SDF. The WTRU and / or UPF may trigger and / or perform a state transition in response to, based on, and / or in association with a sixth trigger condition ("Trigger 6") being met, for example. In some cases, there may be little benefit in performing a state transition to an active state of the redundancy steering mode and transmitting PDUs via the second access network if the second access network does not meet the loss, delay, or variability requirements of the SDF. An example of Trigger 6 may be as follows: Trigger 6:((PLR_1>PLR_thresholdB_3)OR(D_1>D_thresholdB_3)OR(VAR_1>VAR_thresholdB_3))AND((PLR_2 <PLR_thresholdC_1)AND(D_2<D_thresholdC_1)AND(VAR_2<VAR_thresholdC_1))

[0185] Another example of a trigger 6 may be as follows: Trigger 6a: (PLR_1>PLR_thresholdB_3) AND (PLR_thresholdB_3 <PLR_2<PLR_thresholdC_1)

[0186] The WTRU and / or UPF may make a decision regarding a state transition of the redundancy steering mode based on a two-step process. For example, the WTRU and / or UPF may first determine whether duplication over the second access is "necessary" and then determine whether duplication over the second access is "useful." In various embodiments, the WTRU and / or UPF may perform a state transition of the redundancy steering mode from an inactive state to an active state if (e.g., only if) duplication is determined to be necessary and useful.

[0187] Determining the need for replication may be based on one or more of the requirements not being met. For example, the measured PLR on the first access may be higher than the loss requirement. As another example, the measured delay (e.g., RTT) on the first access may be higher than the delay requirement.

[0188] Determining the usefulness of the replication may be based on one or more (e.g., additional) performance metrics. Examples of performance metrics include: (i) replication may be useful if (e.g., only if) the PLR ​​measurements on the second access network meet (e.g., below) a configured threshold (e.g., PLR_thresholdC_1); (ii) replication may be useful if (e.g., only if) the average of the delay measurements on the second access network meets (e.g., less than) a threshold (e.g., D_thresholdD_1); (iii) replication may be useful if (e.g., only if) the variability of delay on the second access network is such that a value equal to the mean + standard deviation of the delay meets (e.g., less than) a threshold (e.g., VAR_thresholdC_1); (iv) replication may be useful if (e.g., only if) the variability of delay on the second access network is such that a value equal to the mean + standard deviation of the delay meets (e.g., less than) a threshold (e.g., VAR_thresholdC_1); *(v) the replication may be useful if (e.g., only if) the variability of delay on the second access network is such that a value equal to the mean minus the standard deviation of delay meets (e.g., is less than) a threshold (e.g., VAR_thresholdC_2); (vi) the replication may be useful if (e.g., only if) the variability of delay on the second access network is such that a value equal to the mean minus the standard deviation of delay meets (e.g., is less than) a threshold (e.g., VAR_thresholdC_3); * (vii) replication may be useful if (e.g., only if) a value equal to the standard deviation is such that it meets (e.g., is less than) a threshold (e.g., VAR_thresholdC_4); (viii) replication may be useful if (e.g., only if) a value equal to the mean-standard deviation of delay < a threshold (e.g., VAR_thresholdC_5) < a value equal to the mean + standard deviation of delay; * Standard deviation equal to threshold (e.g., VAR_thresholdC_6) < mean delay + k * It may be useful if (e.g., only if) the value is equal to the standard deviation.

[0189] In the above, the value of k and the threshold value may be (pre)configured. These values ​​may be based on the type of application, with some applications having values ​​that make it less likely that duplication will be determined to be useful. The AF may provide these values ​​to the network, which may then pass them to the WTRU for ATSSS rules and to the UPF for N4 rules.

[0190] In a first example of a two-step process, the WTRU and / or the UPF may have requirements for loss and delay. In a first step, the transmitting entity may determine that one or both of the requirements are not met on the first access network. For example, the transmitting entity may determine that the PLR ​​may be above a first configured threshold and / or that the delay may be above a second configured threshold. As a result, the outcome of the first step is that replication is needed. In a second step, the transmitting entity may compare the variability of the delay on the second access network to a third threshold. In the following, the variability of the delay is defined as the mean + standard deviation (e.g., a value equal to the mean + standard deviation), but it should be understood that it may be any one of the performance metrics described. The transmitting entity may determine that the mean + standard deviation of the delay is greater than the third threshold. This may indicate that for the SDF and for the current conditions on the second access network, replication is not useful. The transmitting entity may remain in an inactive state. Alternatively, the transmitting entity may determine that the mean plus standard deviation of the delay may be less than a third threshold, which may indicate that replication is useful for the SDF and for the current conditions on the second access network, and the transmitting entity may transition to an active state (and replicate packets).

[0191] Other typical triggers for the redundant steering mode state In addition to and / or instead of triggers based on measurements (PLR, D, VAR, L), the WTRU and / or UPF may decide to change states based on other trigger conditions. These other trigger conditions may be combined (e.g., used together) with the measurement-based triggers. By way of example, the WTRU and / or UPF may trigger and / or perform a dynamic redundancy steering mode state transition (such as per (416A) and / or (416B) of FIG. 4 and the accompanying disclosure) based on one or more of various measurements, measurement-based triggers, and / or other trigger conditions.

[0192] In a first of other trigger conditions for changing the state of the redundancy steering mode, the battery status of the WTRU may trigger the change of state. For example, if the battery status is low, the WTRU may want to limit operation to a single access network so that the second access network can be shut down. In such a case, if the battery status falls below a configured threshold, this may trigger the WTRU to change the state from active to inactive. The WTRU may also have rules that help it select an access network to use in the inactive state based on the access that uses less power.

[0193] In a second of the other trigger conditions for changing the state of the redundancy steering mode, a mobility event in the WTRU may trigger a change in state from inactive to active. During 5G handover, there is an interruption time while the WTRU is attempting to switch to the target cell and during which the WTRU is unable to use its 3GPP access network. For a multi-access PDU session with a redundancy steering mode, a second access network via a non-3GPP access may be used during this interruption time. One or more of the following may trigger a transition from inactive to active: (i) the WTRU sends a measurement report to the source gNB (e.g., this may be for events A2, A3, A4, A5, A6, B1, B2), and (ii) the WTRU receives an RRC reconfiguration message carrying / indicating a configuration for the target cell.

[0194] After redundant transmissions are no longer needed to address the mobility event, the redundancy steering mode may transition back to inactive. One or more of the following may trigger the transition back to inactive: (i) the WTRU hands over to the target cell and sends an RRC reconfiguration complete message to the target gNB, and (ii) the WTRU sends a measurement report to the source gNB (e.g., this may be for event A1).

[0195] In a third triggering condition among the other triggering conditions for changing the state of the redundancy steering mode, the WTRU may trigger a change of state from inactive to active (or active to inactive) for uplink transmission based on an instruction from the network. The instruction may be from the UPF, for example. The UPF may send an instruction to the WTRU to change the state, and the UPF may also indicate which access to use when transitioning to inactive.

[0196] In a fourth trigger condition among the other trigger conditions for changing the state of the redundancy steering mode, the UPF may trigger a state change from inactive to active (or active to inactive) for downlink transmission based on an instruction from the WTRU. For example, the WTRU may send an instruction to the UPF to change the state, and the WTRU may also indicate which access to use when transitioning to inactive. Communication (e.g., signaling) of the instruction between the WTRU and the UPF may be performed using a PMF message. The message may include a QoS flow ID, an SDF ID, and / or a requested state change for the redundancy steering mode.

[0197] In a fifth of the other trigger conditions for changing the state of the redundancy steering mode, the WTRU may trigger a change of state from active to inactive in response to, based on, and / or in association with a path switch on the non-3GPP access network. A 5G system may support a multi-access PDU session with traffic switching between one non-3GPP access network path from the WTRU to the N3IWF in the PLMN and another non-3GPP access network path from the WTRU to the TNGF in the same PLMN. In such a case, the WTRU and UPF may temporarily have three access legs for use: a first access leg on 3GPP, a second access leg on non-3GPP towards the N3IWF, and a third access leg on non-3GPP towards the TNGF. If duplication is active during this time, the WTRU and UPF may have various options.

[0198] In a first option, the WTRU and / or UPF may decide to deactivate the duplication (transition to inactive) and use only the 3GPP access leg, and the WTRU and / or UPF may return to the active state when the WTRU completes its path switch on the non-3GPP access.

[0199] In a second option, the WTRU and / or UPF may decide to use only one of the non-3GPP access legs for duplication. The selection of which non-3GPP access leg may be used may be based on, for example, a configuration received during establishment and / or one or more modifications of the multi-access PDU session. The selection of which non-3GPP access leg may be based on performance measurements on the two non-3GPP access legs. For example, if one leg meets the PLR ​​criterion and the other does not, the WTRU or UPF may decide to prioritize the leg that meets the PLR ​​criterion. The selection of which non-3GPP access leg may be based on implementation or may be randomly selected by the WTRU and / or UPF. The selection of which non-3GPP access leg may be pre-configured (e.g., semi-statically and / or dynamically, via any of Layer 1 (L1), Layer 2 (L2), Layer 3 (L3), and / or higher layer communications, including one or more transmissions that may carry MAC, RRC, and / or other messages and / or information. For example, in the case of a path switch from a source non-3GPP leg to a target non-3GPP leg, the WTRU and the UPF may always use the source non-3GPP leg or may always use the target non-3GPP leg.

[0200] In a sixth trigger condition for changing the state of the redundancy steering mode, the WTRU may trigger a state change from inactive to active in response to, based on, and / or in association with a path switch on the 3GPP access network. The 5G system supports traffic switching on a 3GPP access path from a WTRU using a direct path to the gNB to a WTRU using an indirect path to the gNB (i.e., via an intermediate device). During the path switch, there is an interruption time during which the WTRU cannot use the 3GPP access network. For a multi-access PDU session with a redundancy steering mode, a second access network via a non-3GPP access may be used during this interruption time. The path switch may be used as a trigger to transition from inactive to active.

[0201] In a seventh triggering condition among the other triggering conditions for changing the state of the redundancy steering mode, the WTRU may trigger a change of state from inactive to active in response to, based on, and / or in association with a pending radio link failure on the 3GPP path. The WTRU constantly monitors the RLF failure condition (e.g., based on a physical layer issue). When the WTRU detects that a radio link failure on the 3GPP path is pending, it may decide to trigger a transition to the active redundancy steering mode to enable some connectivity between the WTRU and the UPF.

[0202] In an eighth triggering condition among other triggering conditions for changing the state of the redundancy steering mode, the WTRU may trigger a change of state from active to inactive based on an overheating condition. The WTRU may monitor the overheating status and notify the gNB when the overheating condition is met. If the redundancy steering mode is active for the WTRU and the WTRU detects an overheating condition, the WTRU may decide to transition to an inactive status. For example, this may help reduce power or allow the WTRU to turn off radio components corresponding to the non-3GPP access network.

[0203] In a ninth of the other trigger conditions for changing the state of the redundancy steering mode, the WTRU may trigger a change of state from active to inactive (and vice versa) based on an instruction from a user provided through a user interface. The user may decide to force the WTRU to activate the duplicate or to deactivate the duplicate.

[0204] In a tenth trigger condition among other trigger conditions for changing the state of the redundancy steering mode, the WTRU and / or UPF may be provided with a schedule for activating or deactivating the duplication. The network may determine the schedule based on input from the WTRU, one or more application servers, one or more RAN nodes, the NWDAF, etc. The schedule may be provided to the WTRU and / or UPF (e.g., semi-statically and / or dynamically, either via L1, L2, L3, etc., communications including one or more transmissions that may carry, e.g., MAC, RRC, and / or other messages and / or information). The WTRU and / or UPF may activate and deactivate the duplication based on the schedule. The WTRU may know from its traffic profile that it generates very periodic traffic. For example, the WTRU may know that every 100 ms, an application generates one packet that requires very high throughput and low latency. In such an example, the WTRU may configure the schedule such that the duplication is active for 10 ms every 100 ms.

[0205] In an eleventh triggering condition among the other triggering conditions for changing the state of the redundant steering mode, the WTRU and / or the UPF may trigger a change in state based on other steering modes enabled for other SDFs between the WTRU and / or the UPF. For example, the WTRU and / or the UPF may be configured to deactivate duplication if the other steering mode is not enabled, or the WTRU and the UPF may be configured to activate duplication if the WTRU is already using a non-3GPP path for another steering mode.

[0206] Representative communication for state change of redundant steering mode With reference to FIG. 6, when a WTRU (or UPF) changes the state of the redundancy steering mode, it may be useful to inform a peer entity (UPF (or WTRU)) about the change of state. A communication exchange (600) (e.g., a signaling exchange) between the WTRU and the UPF may be performed via any of L1, L2, L3, etc., communications including one or more transmissions that may carry, for example, MAC, RRC, and / or PMF messages. The PMF message may include a QoS flow ID, a service data flow ID, an active or inactive status of the redundancy steering mode, and / or instructions to pause duplication (inactive) and resume duplication (active status). After receiving the PMF message from the WTRU and / or in response thereto, the UPF may inform the affected access network nodes (602). After receiving and / or in response to the PMF message from the UPF (604), the WTRU may take any of the following actions: (i) stop making measurements on any access networks that are being removed, and (ii) if necessary, enter IDLE mode on any access networks that are being removed (606).

[0207] A duration may also be specified in the PMF message. This duration may indicate how long the transition to inactive or active (or vice versa) should apply. For example, if the WTRU is undergoing a 5G handover and redundancy is needed for a short period of time, a duration (e.g., 3 seconds) may be specified. In this case, the WTRU and / or UPF will switch back to inactive after 3 seconds. The same access network used before the quick switch to active is reused in the inactive mode.

[0208] More generally, when the WTRU (or UPF) changes the state of the redundancy steering mode, it may be useful to inform the peer entity (UPF (or WTRU)) of the state change, e.g., with one or more signaling messages, using any of L1, L2, L3, etc. communications. The signaling messages may include one or more of the following: (i) information indicating a PDU Session ID, (ii) information indicating one or more QoS Flow IDs, (iii) information indicating one or more SDF IDs, (iv) information indicating an active or inactive status of the redundancy steering mode, (v) information indicating the duration of the state of the redundancy steering mode ("state duration") (e.g., one for a single or one for each state), (vi) information indicating a schedule for performing replication ("replication schedule"), (vii) information indicating one or more triggers that caused the state change, and (viii) an indication and / or information indicating a request from the peer that a return link may cause the replication state to change.

[0209] The active or inactive status of the redundancy steering mode may be given, for example, per PDU session, per QoS flow, or per SDF.

[0210] Each state duration of the redundancy steering mode may indicate how long the redundancy steering mode should remain in the inactive or active state, for example, following a state transition to inactive or active (or vice versa). As an example, the WTRU may be engaged in a 5G handover and redundancy may be needed for a period of time (e.g., a short period of time). A state duration (e.g., 3 seconds) for the active (or next occurring) state may be specified for this purpose. The WTRU and UPF may switch the redundancy steering mode back to inactive after 3 seconds. The same access network used before the quick switch to active may be reused in the inactive mode.

[0211] The replication schedule may be based on a traffic profile that may have been determined by the WTRU or the UPF. The WTRU (or UPF) may provide this schedule to the UPF (or WTRU). The replication schedule may indicate one or more periods during which the redundancy steering mode should be in an active state. The WTRU and UPF may switch the redundancy steering mode to and from the active state according to the schedule (e.g., perform switching to be in the active state for the entire duration of each period or initiate switching at the beginning and end of each period).

[0212] The trigger that caused the state change may be determined by the WTRU (or UPF). The WTRU (or UPF) may inform its peer (UPF (or WTRU)) of the trigger that caused the state change. The state change may be the result of any of the following: user indication, overheating, pending RLF, upcoming handover, performance metrics (PLR, delay, delay variability, access load, etc.), etc.

[0213] An indication and / or information indicating a request that a return link from a peer-modified replication state may be used, for example, when the uplink and downlink may not be in the same redundancy steering mode state. For example, the uplink may have replication activated, while the downlink may have replication deactivated. A request that a return link from a peer-modified replication state may be for a specification case in which the 3GPP path uses frequency division duplexing (FDD) and, as a result, has different performance metrics for the uplink and downlink. In such a case, the transmitting entity (WTRU or UPF) on the forward link may notify the receiving entity (UPF or WTRU) that the state should be changed for the return link. The signaling message may notify the peer entity to use the same replication state as the forward link, or may specify a specific replication state to use for the return link.

[0214] In the following, for ease of explanation, it is assumed that the above information is included in a duplication state (DS) information element (IE) carried in one or more (e.g., signaling) messages. This should be interpreted as an exemplary implementation. It should be understood that only a subset of the above information may be included in the DS IE, or the information may be included in multiple IEs.

[0215] Communication (e.g., signaling) between the WTRU and the UPF may be performed via any of L1, L2, L3, etc., including one or more transmissions that may carry, for example, MAC, RRC, and / or PMF messages and / or information. A new PMF message may be defined to carry this information (e.g., PMFP replication state). This message may be bidirectional (WTRU to UPF and UPF to WTRU). Alternatively, the IE may be included within an existing PMF message (such as PMFP Access Report or PMFP UAD Provisioning). Since these messages are unidirectional, they may be redefined to be bidirectional. As a third alternative, the IE may be included in an existing PMF message (such as PMFP Access Report or PMFP UAD Provisioning) for the WTRU to UPF direction, and an equivalent PMF message, such as PMFP Access Report 1 or PMFP UAD Provisioning 1, is defined for the UPF to WTRU direction. If the WTRU and UPF have a QUIC connection (e.g., a MASQUE connection over QUIC), signaling between the WTRU and UPF may be done through QUIC messages. The DS IE may be added in the QUIC message (e.g., a CAPSULE protocol message sent over the MASQUE connection). The client (e.g., the WTRU) sets this IE in the CAPSULE protocol message sent to the server (e.g., a proxy) in a QUIC packet.

[0216] If the WTRU and the UPF have a DCCP connection, the DS IE may be added as a new DCCP option in the DCCP request / response messages.

[0217] After receiving and / or in response to the signaling message from the WTRU, the UPF may perform one or more of the following: (i) inform the affected access nodes about the legs to be activated or deactivated, (ii) activate or deactivate replication based on the request in the signaling message, (iii) store active-to-inactive and inactive-to-active transitions according to the replication schedule and the reception schedule, (iv) store state transitions and durations of active-to-inactive or inactive-to-active transitions, and accordingly (v) notify the AF about the change in replication state of the redundancy steering mode.

[0218] After receiving and / or in response to a signaling message from the UPF, the WTRU may perform one or more of the following actions: (i) if the redundancy steering mode is becoming inactive and an access network is being removed, the WTRU may stop making measurements on any access network being removed; (ii) if the redundancy steering mode is becoming active and an access network is being added, the WTRU may (re)start making measurements on any access network being added; (iii) if the redundancy steering mode is becoming inactive and an access network is being removed and there is no other SDF across the access being removed, the WTRU may stop receive processing on the access being removed; (iv) if the redundancy steering mode is becoming active and an access network is being added and there is no SDF across the access being added, the WTRU may start receive processing on the access being added; (v) if the redundancy steering mode is becoming inactive and an access network is being added and there is no SDF across the access being added, the WTRU may start receive processing on the access being added; (vi) the WTRU may discard any duplicate packets received on the removed access network at the ATSSS layer; (vii) if the redundancy steering mode is being activated and an access network is being added and there is a SDF across the added access network, the WTRU may (re)start processing duplicate packets at the ATSSS layer; (viii) the WTRU may use different measurement criteria on the access; (ix) if the UPF informs the WTRU that the redundancy steering mode is now inactive and the non-3GPP path has been removed, the WTRU may start making further measurements on the 3GPP path to more quickly determine when the redundancy steering mode should become active again; (x) the WTRU may, based on the request in the signaling message,(xi) the WTRU stores the replication schedule and can transition from active to inactive and from inactive to active according to the received schedule; (xii) the WTRU stores the duration of the state transition and can transition from active to inactive and from inactive to active accordingly; (xiii) the WTRU can transition to IDLE mode on the access network being removed, if necessary;

[0219] 7 is a flow chart illustrating an example flow 700 for use in connection with multi-access PDU session establishment and / or modification. Flow 700 and the accompanying disclosure herein may be considered a generalization of at least some of the disclosures accompanying FIGS. 4-6 and may be considered to encompass and / or include various embodiments of the disclosures above, including at least some of the disclosures accompanying FIGS. 4-6. Flow 700 may be performed using the architecture of communication system 100 of FIGS. 1A-1D. Flow 700 may also be performed using other architectures.

[0220] 7, the WTRU may receive first information indicating that traffic steering is supported via a first network element during a registration procedure (702). In various embodiments, the first network element may be, for example, an AMF. In various embodiments, the first information may include a multi-access PDU session support indicator.

[0221] The WTRU may transmit to the first network element second information that may indicate one or more redundancy steering mode capabilities of the WTRU (704). In various embodiments, the redundancy steering mode capabilities of the WTRU may be or include ATSSS capabilities. In various embodiments, the ATSSS capabilities (redundancy steering mode capabilities) may include any of support for a redundant traffic steering mode, support for duplication detection, and support for a specific steering function. In various embodiments, the second information may indicate one of a request to establish a multi-access protocol PDU session or a request to modify a multi-access PDU session. As an example, the second information may be a PDU session establishment request or a PDU session modification request with information regarding the redundancy steering mode capabilities of the WTRU.

[0222] The WTRU may receive third information, e.g., via a second network element, where the third information may indicate one or more rules for the redundancy steering mode (706). In various embodiments, the third information may indicate a response to one of the request to establish a multi-access PDU session or the request to modify the multi-access PDU. By way of example, the third information may be a PDU session establishment request accept message having information regarding (e.g., indicative of) at least one of the ATSSS rules for the redundancy steering mode and other rules for the redundancy steering mode. In various embodiments, the WTRU may expect to receive information indicative of at least one rule for the redundancy steering mode based on transmitting the first information indicative of one or more redundancy steering mode capabilities of the WTRU.

[0223] The WTRU may configure a static or dynamic redundancy steering mode for the SDF based on the received rules 708. The WTRU may transmit one or more PDUs of the SDF in the configured redundancy steering mode according to the rules (e.g., at least one of ATSSS rules or other rules) 710.

[0224] In various embodiments, the redundancy steering rules may include information indicating that the redundancy steering mode may be “static” or “dynamic.” In various embodiments, receiving information indicating whether or not performing duplicate detection and discarding is mandatory for the ATSSS-LL steering function.

[0225] In various embodiments, a dynamic steering mode is configured, and the redundancy steering rule (e.g., ATSSS rule) may include information indicating whether the initial state of the steering mode may be active or inactive. If inactive, the initial PDU transmission of the service data flow may be via 3GPP access or non-3GPP access.

[0226] In various embodiments, a dynamic steering mode is configured and the measurement configuration includes thresholds for one or more of PLR, delay, delay variability, access load, etc. In various embodiments, a transition from inactive to active occurs only when a single access cannot meet all requirements of the SDF and using both accesses can meet all requirements of the SDF. This decision can be based on a combination of conditions related to the PLR ​​at each access, the delay at each access, the delay variability at each access, and the load at each access.

[0227] In various embodiments, a transition from active to inactive may occur only when a single access can satisfy all requirements of the SDF. This decision may be based on a combination of conditions related to the PLR ​​at each access, the delay at each access, the variability of the delay at each access, and the load at each access.

[0228] In various embodiments where the dynamic steering mode is configured, the transition may occur based on one or more of the following: UE battery status, mobility events, based on a message from the network. In various embodiments, the message from the network may include a state duration. In various embodiments, if the transition is to inactive, the message from the network may include an indication of which access to use.

[0229] 8 is a flow chart illustrating an example flow 800 according to various embodiments. Flow 800 and the accompanying disclosure herein may be considered a generalization of at least some of the disclosures accompanying FIGS. 4-6 and may be considered to encompass and / or include various embodiments of the disclosures above, including, for example, at least some of the disclosures accompanying FIGS. 4-7. Flow 800 may be performed using the architecture of communication system 100 of FIGS. 1A-1D. Flow 800 may also be performed using other architectures.

[0230] 8, the WTRU may receive first information indicating that traffic steering is supported from a network element during a registration procedure (802). In various embodiments, the first network element may be, for example, an AMF. In various embodiments, the first information may be or may include a multi-access PDU session support indicator.

[0231] The WTRU may transmit to the first network element second information that may indicate one or more redundancy steering mode capabilities of the WTRU (804). In various embodiments, the redundancy steering mode capability of the WTRU may be or include ATSSS capability. In various embodiments, the ATSSS capability (redundancy steering mode capability) may include any of support for a redundant traffic steering mode, support for duplication detection, and support for a specific steering function. In various embodiments, the second information may indicate one of a request to establish a multi-access protocol PDU session or a request to modify a multi-access PDU session. As an example, the second information may be a PDU session establishment request or a PDU session modification request with information regarding the redundancy steering mode capability of the WTRU.

[0232] The WTRU may receive third information, e.g., via a second network element, where the third information may indicate one or more rules for the redundancy steering mode (806). In various embodiments, the third information may indicate a response to one of the request to establish a multi-access PDU session or the request to modify the multi-access PDU. By way of example, the third information may be a PDU session establishment request accept message having information regarding (e.g., indicative of) at least one of an ATSSS rule for the redundancy steering mode and other rules for the redundancy steering mode. In various embodiments, the WTRU may expect to receive information indicative of at least one rule for the redundancy steering mode based on transmitting the first information indicative of one or more redundancy steering mode capabilities of the WTRU.

[0233] The WTRU may transmit a PDU associated with the multi-access PDU session via at least one of the first and second access networks (808), where (i) the PDU is transmitted via the first and second access networks based on a first rule and first values ​​of the two or more metrics associated with each of the first and second access networks, and (ii) the PDU is transmitted via one of the first and second access networks based on a second rule and second values ​​of the two or more metrics associated with each of the first and second access networks.

[0234] In various embodiments, at least one of the one or more rules may indicate that PDU duplication for the redundancy steering mode is inactive (or active), and the WTRU may be configured to transmit a PDU based on the indicated PDU duplication based on the absence of any values ​​for one or more of the metrics associated with each of the first and second access networks. In various embodiments, the first rule may indicate using the first and second access networks, provided that neither (i) a first value of the two or more metrics associated with the first access network nor (ii) a first value of the two or more metrics associated with the second access network meets a respective threshold value.

[0235] 9 is a flow chart illustrating an example flow 900 according to various embodiments. Flow 900 and the accompanying disclosure herein may be considered a generalization of at least some of the disclosures accompanying FIGS. 4-6 and may be considered to encompass and / or include various embodiments of the disclosures above, including at least some of the disclosures accompanying FIGS. 4-8, for example. Flow 900 may be performed using the architecture of communication system 100 of FIGS. 1A-1D. Flow 900 may also be performed using other architectures.

[0236] 9, the WTRU may transmit first information indicating one of a request to establish a multi-access PDU session or a request to modify a multi-access PDU session to a first network element (902). The WTRU may receive second information indicating a response to one of the requests to establish a multi-access PDU session or to modify a multi-access PDU session via a second network element (904). The WTRU may determine first values ​​of a plurality of metrics for the first access network (906). The WTRU may determine second values ​​of a plurality of metrics for the second access network (906). The WTRU may determine to transmit a PDU associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks based on the rules for the redundancy steering mode and the first and second values ​​of the plurality of metrics that satisfy respective conditions of the rules (908). The WTRU may transmit the PDU via one of the first access network, the second access network, or the first and second access networks.

[0237] In various embodiments, the PDU is a PDU of an SDF associated with a multi-access PDU session. In various embodiments, based on the rule, a state transition of the redundancy steering mode from inactive to active is performed on a condition that only a single access network of the first and second access networks cannot meet the requirements of the SDF. In various embodiments, based on the rule, a state transition of the redundancy steering mode from active to inactive is performed on a condition that only a single access network of the first and second access networks can meet the requirements of the SDF.

[0238] In various embodiments, information is received from the network indicating a duration of the state of the redundant steering mode. In various embodiments, information is received for the duration indicating whether the first or second access network should be used. In various embodiments, measurements on either the first and second access networks that are removed are paused for the duration. In various embodiments, the WTRU transitions to an IDLE mode on the access that is removed for the duration.

[0239] In various embodiments, the first information indicates one or more redundancy steering mode capabilities of the WTRU and the second information indicates one or more rules for the redundancy steering mode, including the rules.

[0240] In various embodiments, the multiple metric network element is an access and mobility management function. In various embodiments, the second network element is a base station. In various embodiments, the second network element is a base station associated with the first access network, the second access network, or a second access network different from a first one of the first and second access networks.

[0241] In various embodiments, the plurality of metrics includes any two of packet loss rate, delay, delay variability, and load.

[0242] In various embodiments, the one or more rules for the redundancy steering mode include information indicating an initial state of the redundancy steering mode is one of active and inactive. In various embodiments, the initial PDU transmission of the SDF is transmitted via one of the first access network, the second access network, or the first and second access networks based on the initial state of the redundancy steering mode being one of active and inactive.

[0243] In various embodiments, the one or more rules include information indicative of a measurement configuration for the plurality of metrics. In various embodiments of the apparatus, the circuitry is configured to expect to receive the information indicative of the at least one rule for the redundant steering mode based on transmitting the first information indicative of the one or more redundant steering mode capabilities of the WTRU. In various embodiments of the method, the method can include expecting to receive the information indicative of the at least one rule for the redundant steering mode based on transmitting the first information indicative of the one or more redundant steering mode capabilities of the WTRU.

[0244] In various embodiments of the method, the method can receive third information indicating that traffic steering is supported via the second network element during the registration procedure. In various embodiments of the method, determining to transmit the PDU can include determining to transmit the PDU via the first and second access networks based on the rule, first and second values ​​of the plurality of metrics satisfying respective conditions of the rule, and the rule indicating that PDU duplication for the redundancy steering mode is inactive, and transmitting the PDU can include transmitting the PDU based on the indicated PDU duplication.

[0245] In various embodiments of the apparatus, the circuitry configured to determine to transmit or receive a PDU includes circuitry configured to determine to transmit the PDU via the first and second access networks based on the rule, first and second values ​​of the plurality of metrics that satisfy respective conditions of the rule, and the rule indicating that PDU duplication for the redundancy steering mode is inactive, and the circuitry configured to transmit the PDU includes circuitry configured to transmit the PDU based on the indicated PDU duplication.

[0246] 10 is a flow chart illustrating an example flow 1000 according to various embodiments. Flow 1000 and the accompanying disclosure herein may be considered a generalization of at least some of the disclosures accompanying FIGS. 4-6 and may be considered to encompass and / or include various embodiments of the disclosures above, including at least some of the disclosures accompanying FIGS. 4-8, for example. Flow 1000 may be performed using the architecture of communication system 100 of FIGS. 1A-1D. Flow 1000 may also be performed using other architectures.

[0247] 10, a WTRU may transmit first information indicating one of a request to establish a multi-access protocol data unit (PDU) session or a request to modify a multi-access PDU session to a first network element (1002). The WTRU may receive second information indicating a response to one of the requests to establish a multi-access PDU session or to modify a multi-access PDU session via a second network element (1003). The WTRU may determine to transmit or receive a PDU associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks based on the rule for the redundancy steering mode and a first value of a plurality of metrics for the first access network and a second value of a plurality of metrics for the second access network that satisfy respective conditions of the rule (1006). The WTRU may perform one of transmitting and receiving a PDU via one of the first access network, the second access network, or the first and second access networks.

[0248] In various embodiments, the PDU is a PDU of an SDF associated with a multi-access PDU session. In various embodiments, based on the rule, a state transition of the redundancy steering mode from inactive to active is performed on a condition that only a single access network of the first and second access networks cannot meet the requirements of the SDF. In various embodiments, based on the rule, a state transition of the redundancy steering mode from active to inactive is performed on a condition that only a single access network of the first and second access networks can meet the requirements of the SDF.

[0249] In various embodiments, information is received from the network indicating a duration of the state of the redundant steering mode. In various embodiments, information is received for the duration indicating whether the first or second access network should be used. In various embodiments, measurements on either the first and second access networks that are removed are paused for the duration. In various embodiments, the WTRU transitions to an IDLE mode on the access that is removed for the duration.

[0250] In various embodiments, the first information indicates one or more redundancy steering mode capabilities of the WTRU and the second information indicates one or more rules for the redundancy steering mode, including the rules.

[0251] In various embodiments, the multiple metric network element is an access and mobility management function. In various embodiments, the second network element is a base station. In various embodiments, the second network element is a base station associated with the first access network, the second access network, or a second access network different from a first one of the first and second access networks.

[0252] In various embodiments, the plurality of metrics includes any two of packet loss rate, delay, delay variability, and load.

[0253] In various embodiments, the one or more rules for the redundancy steering mode include information indicating an initial state of the redundancy steering mode is one of active and inactive. In various embodiments, the initial PDU transmission of the SDF is transmitted via one of the first access network, the second access network, or the first and second access networks based on the initial state of the redundancy steering mode being one of active and inactive.

[0254] In various embodiments, the one or more rules include information indicative of a measurement configuration for the plurality of metrics. In various embodiments of the apparatus, the circuitry is configured to expect to receive the information indicative of the at least one rule for the redundant steering mode based on transmitting the first information indicative of the one or more redundant steering mode capabilities of the WTRU. In various embodiments of the method, the method can include expecting to receive the information indicative of the at least one rule for the redundant steering mode based on transmitting the first information indicative of the one or more redundant steering mode capabilities of the WTRU.

[0255] In various embodiments of the method, the method can receive third information indicating that traffic steering is supported via the second network element during the registration procedure. In various embodiments of the method, determining to transmit the PDU can include determining to transmit the PDU via the first and second access networks based on the rule, first and second values ​​of the plurality of metrics satisfying respective conditions of the rule, and the rule indicating that PDU duplication for the redundancy steering mode is inactive, and transmitting the PDU can include transmitting the PDU based on the indicated PDU duplication.

[0256] In various embodiments of the apparatus, the circuitry configured to determine to transmit or receive a PDU includes circuitry configured to determine to transmit the PDU via the first and second access networks based on the rule, first and second values ​​of the plurality of metrics that satisfy respective conditions of the rule, and the rule indicating that PDU duplication for the redundancy steering mode is inactive, and the circuitry configured to transmit the PDU includes circuitry configured to transmit the PDU based on the indicated PDU duplication.

[0257] The following references may have been mentioned above and are incorporated by reference herein in their entireties:

[0258] RFC 8684, TCP Extensions for Multipath Operation with Multiple Addresses; 3rd Generation Partnership Project ("3GPP"); Service Requirements for 5G Systems, 3GPP TS 22.261 V18.5.0; 3GPP; Technical Specification Group Services and System Aspects; Procedures for 5G Systems (5GS); Stage 2, (Release 17), 3GPP 23.502 v17.3.0; 3GPP; Technical Specification Group Services and System Aspects; System Architecture for 5G Systems (5GS); Stage 2, (Release 17), 3GPP TS 23.501 v17.3.0); 3GPP;Study on access traffic steering,switch and splitting support in the 5G System(5GS)architecture,3GPP TRS 23.700-93 V17.0.0 and SP-211612, New SID on Access Traffic Steering, Switching and Splitting support in the 5G system architecture; Phase 3, SP-94E, December 14-20, 2021.

[0259] conclusion Although features and elements are provided above in specific combinations, one skilled in the art will understand that each feature or element can be used alone or in any combination with other features and elements. The present disclosure is not limited in terms of the specific embodiments described in this application, which are intended as illustrations of various aspects. As will be apparent to those skilled in the art, many modifications and variations may be made without departing from the spirit and scope of the present invention. No element, operation, or instruction used in the description of this application should be construed as critical or essential to the invention unless expressly set forth as such. In addition to those enumerated herein, functionally equivalent methods and apparatuses within the scope of the present disclosure will be apparent to those skilled in the art from the foregoing description. 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 the present disclosure is not limited to any particular method or system.

[0260] The foregoing embodiments are discussed with respect to the terminology and structure of infrared-enabled devices (i.e., infrared emitters and receivers) for simplicity, however, the discussed embodiments are not limited to these systems and may also be applied to other systems that use other forms of electromagnetic waves, or non-electromagnetic waves such as acoustic waves.

[0261] It should also be understood that the terms used herein are for purposes of describing particular embodiments only and are not intended to be limiting. As used herein, the term "video" or "image" may mean either a snapshot, a single image, and / or multiple images displayed over time. As another example, the term "user equipment" and its abbreviation "UE", the term "remote", and / or the term "head mounted display" and its abbreviation "HMD" as referred to herein may mean or include (i) a wireless transmitting and / or receiving unit (WTRU), (ii) any of several embodiments of a WTRU, (iii) a wireless enabled and / or wired enabled (e.g., tetherable) device specifically configured to have some or all of the structure and functionality of a WTRU, (iii) a wireless enabled and / or wired enabled device configured to have less than all of the structure and functionality of a WTRU, or (iv) the like. Details of an exemplary WTRU that may represent any WTRU listed herein are provided herein with respect to FIGS. 1A-1D. As another example, various embodiments disclosed herein above and below are described as utilizing a head-mounted display. Those skilled in the art will recognize that devices other than a head-mounted display may be utilized and that the present disclosure and any or all of the various disclosed embodiments may be modified accordingly without undue experimentation. Examples of such other devices may include drones or other devices configured to stream information to provide an adaptive reality experience.

[0262] In addition, the methods provided herein may be implemented in a computer program, software, or firmware embodied 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, read only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital versatile 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, MME, EPC, AMF, or any host computer.

[0263] Modifications of the methods, apparatus, and systems provided above are possible without departing from the scope of the present invention. In view of the wide variety of embodiments that may be applied, it should be understood that the illustrated embodiments are merely examples and should not be construed as limiting the scope of the following claims. For example, the embodiments provided herein include a portable device, which may include or be utilized with any suitable voltage source, such as a battery providing any suitable voltage.

[0264] Further, in the above embodiments, it should be noted that processing platforms, computing systems, controllers, and other devices including processors. These devices may include at least one Central Processing Unit (CPU) and memory. In accordance with the practices of those skilled in the art of computer programming, references to operations and symbolic representations of operations or instructions may be performed by various CPUs and memories. Such operations and operations or instructions may be referred to as being "executed," "computer executed," or "CPU executed."

[0265] Those skilled in the art will appreciate that the operations and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. The electrical system represents data bits that may cause a resultant transformation or reduction of the electrical signals, and maintains the data bits in memory locations of the memory system, thereby reconfiguring or otherwise altering the operation of the CPU and the processing of other signals. The memory locations in which the data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties that correspond to or represent the data bits. It should be appreciated that the embodiments are not limited to the platforms or CPUs mentioned above, and that other platforms and CPUs may support the methods provided.

[0266] 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 a CPU. The computer readable medium may include computer readable media that resides exclusively on a processing system, or distributed, cooperative or interconnected among multiple interconnected processing systems that may be local or remote to a processing system. It should be understood that the embodiments are not limited to the memories mentioned above and that other platforms and memories may support the methods provided.

[0267] In an example 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, a network element, and / or any other computing device.

[0268] There is little distinction between hardware and software implementations of aspects of the system. Whether to use hardware or software is generally a design choice that represents a cost vs. efficiency tradeoff (although in some circumstances the choice between hardware and software may be important). There may be a variety of vehicles (e.g., hardware, software, and / or firmware) in which the processes and / or systems and / or other techniques described herein may be effective, and the preferred vehicle may vary depending on the context in which the processes and / or systems and / or other techniques are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may select a primarily hardware and / or firmware vehicle. If flexibility is paramount, the implementer may select a primarily software implementation. Alternatively, the implementer may select some combination of hardware, software, and / or firmware.

[0269] The foregoing detailed description has illustrated various embodiments of devices and / or processes through the use of block diagrams, flow charts, and / or examples. To the extent that such block diagrams, flow charts, and / or examples include one or more functions and / or operations, it will be appreciated by those skilled in the art that each function and / or operation within such block diagrams, flow charts, or examples may be individually and / or collectively implemented by a wide range of hardware, software, firmware, or substantially any combination thereof. In one embodiment, some 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 forms. However, those skilled in the art will recognize that certain aspects of the embodiments disclosed herein may be equivalently implemented, in whole or in part, 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 substantially any combination thereof, and that designing circuitry and / or writing software and / or firmware code is within the skill of those skilled in the art in light of this disclosure. In addition, those skilled in the art will recognize that the subject matter mechanisms described herein may be distributed as program products in a variety of forms, and that representative embodiments of the subject matter described herein apply regardless of the particular type of signal-bearing medium used to actually effect the distribution. Examples of signal bearing media include, but are not limited to, recordable type media such as floppy disks, hard disk drives, CDs, DVDs, digital tape, computer memory, and transmission type media such as digital and / or analog communications media (e.g., fiber optic cables, wave guides, wired communications links, wireless communications links, etc.).

[0270] Those skilled in the art will recognize that it is common in the art to describe devices and / or processes in the manner described herein and then use engineering techniques to integrate such described devices and / or processes into a data processing system. That is, at least a portion of the devices and / or processes described herein may be integrated into a data processing system through a reasonable amount of experimentation. Those skilled 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, memory such as volatile and non-volatile memory, a processor such as a microprocessor and a digital signal processor, computing entities such as an operating system, drivers, graphical user interfaces, and application programs, one or more interactive devices such as a touchpad or screen, and / or a control system including feedback loops and control motors (e.g., feedback to sense position and / or velocity, control motors to move and / or adjust 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 systems and / or network computing / communication systems.

[0271] The subject matter described herein may illustrate different components that are included within or connected to different other components. It should be understood that such depicted architectures are merely examples, and that in fact many other architectures that achieve the same functionality may be implemented. Conceptually, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality may be achieved. Thus, any two components herein that are combined to achieve a particular functionality may be considered to be "associated" with one another such that the desired functionality is achieved, regardless of the architecture or intervening components. Similarly, any two components so associated may be considered to be "operably connected" or "operably coupled" with one another to achieve the desired functionality, and any two components that can be associated in this way may be considered to be "operably couplable" with one another to achieve the desired functionality. Examples of operably coupleable include, but are not limited to, physically matable and / or physically interacting components, and / or wirelessly interactable and / or wirelessly interacting components, and / or logically interacting and / or logically interacting components.

[0272] With respect to the use of substantially any plural and / or singular term herein, those of skill in the art may convert from plural to singular and / or from singular to plural as appropriate to the context and / or application. For purposes of clarity, various singular / plural permutations may be expressly set forth herein.

[0273] In general, those skilled in the art will understand that the terms used in this specification, and particularly in the appended claims (e.g., the body 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," and the term "includes" should be interpreted as "includes but is not limited to"). Furthermore, those skilled in the art will understand that where a specific number of recitations of an introduced claim are intended, such intention is expressly set forth in the claim, and in the absence of such recitation, no such intention exists. For example, where only one item is intended, the term "single" or similar language may be used. To aid in understanding, the following appended claims and / or the description of this specification may include the use of the introductory phrases "at least one" and "one or more" to introduce the claim recitations. However, the use of such phrases should not be interpreted as meaning that the introduction of a claim recitation with the indefinite article "a" or "an" limits any particular claim that includes such an introduced claim recitation to an embodiment that includes only such one recitation, even if the same claim contains the introductory phrase "one or more" or "at least one" and an indefinite article 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 applies to the use of definite articles used to introduce claim recitations. In addition, those skilled in the art will recognize that even if a specific number of recitations of an introduced claim are explicitly recited, such recitation should be interpreted to mean at least the recited number (e.g., the simple recitation "two recitations" without any other qualifiers means at least two recitations, or more than two recitations).Furthermore, when notation similar to "such as at least one of A, B, and C" is used, such structure is generally intended as a person of ordinary skill in the art would understand the notation (e.g., "a system having at least one of A, B, and C" includes, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together). When notation similar to "such as at least one of A, B, or C" is used, such structure is generally intended as a person of ordinary skill in the art would understand the notation (e.g., "a system having at least one of A, B, or C" includes, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together). Those skilled in the art will further appreciate that virtually any disjunctive word and / or phrase presenting two or more alternative terms, whether in the specification, claims, or drawings, should be understood to contemplate the possibility of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" should be understood to include the possibilities of "A" or "B" or "A and B." Additionally, as used herein, the term "any of" followed by a list of items and / or a list of categories of items is intended to include "any of," "any combination of," "any more than," and / or "any more than," of the items and / or categories of items, individually or in combination with other items and / or other categories of items. Additionally, 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. Also, as used herein, the term "multiple" is intended to be synonymous with "a plurality."

[0274] In addition, where features or aspects of the disclosure are described in terms of a Markush group, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual members or subgroups of members of the Markush group.

[0275] As will be appreciated by those skilled in the art, for all purposes, including in terms of providing a written description, all ranges disclosed herein also encompass any possible subranges and combinations of subranges thereof. Any recited range can be readily recognized as fully descriptive and allowing the same range to be 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, a middle third, an upper third, etc. As will also be appreciated by those skilled in the art, all words such as "up to," "at least," "greater than," "less than" and the like refer to ranges that include the recited numbers and that can be further broken down into subranges as discussed above. Finally, as will be appreciated by those skilled in the art, a range includes each individual element. Thus, for example, a group having 1 to 3 cells refers to a group having 1, 2, or 3 cells. Similarly, a group having 1 to 5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so on.

[0276] Moreover, the claims should not be read as limited to the provided order or to the provided elements unless specifically so stated. In addition, the use of the term "means for" in any claim is intended to invoke 35 U.S.C. ...

[0277] Suitable processors include, by way of example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), an application specific standard product (ASSP), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), and / or a state machine.

[0278] The WTRU may be used in conjunction with hardware and / or software implemented modules, such as, for example, a Software Defined Radio (SDR), and may be implemented in other components, such as a camera, a video camera module, a video phone, a speaker phone, a vibration device, a speaker, a microphone, a television transceiver, a hands-free headset, a keyboard, a Bluetooth module, a Frequency Modulation (FM) radio unit, a Near Field Communication (NFC) module, an LCD display unit, an Organic Light Emitting Diode (OLED) display unit, a digital music player, a media player, a video game player module, an Internet browser, and / or a Wireless Local Area Network (WLAN) or Ultra Wide Band (UWB) module.

[0279] Although various embodiments have been described with respect to a communications system, it is contemplated that the system may be implemented in software on a microprocessor / general purpose computer (not shown). In particular embodiments, one or more of the functions of the various components may be implemented in software controlling a general purpose computer.

[0280] In addition, although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications can be made in the details within the scope of the claims and their equivalents and without departing from the invention.

Claims

1. 1. A method implemented in a wireless transmit / receive unit (WTRU), comprising: transmitting, to a first network element, first information indicating one of a request to establish a multi-access protocol data unit (PDU) session or a request to modify a multi-access PDU session; receiving, via a second network element, second information indicating a response to one of the request to establish a multi-access PDU session or the request to modify the multi-access PDU session; determining first values ​​of a plurality of metrics for a first access network; determining second values ​​of the plurality of metrics for a second access network; determining, based on rules for a redundancy steering mode and the first and second values ​​of the plurality of metrics satisfying respective conditions of the rules, to transmit a PDU associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks; transmitting the PDU via the one of the first access network, the second access network, or the first and second access networks.

2. 1. A method implemented in a wireless transmit / receive unit (WTRU), comprising: transmitting, to a first network element, first information indicating one of a request to establish a multi-access protocol data unit (PDU) session or a request to modify a multi-access PDU session; receiving, via a second network element, second information indicating a response to one of the request to establish a multi-access PDU session or the request to modify the multi-access PDU session; determining first values ​​of a plurality of metrics for a first access network; determining second values ​​of the plurality of metrics for a second access network; determining to receive a PDU associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks based on rules for a redundancy steering mode and the first and second values ​​of the plurality of metrics satisfying respective conditions of the rules; receiving the PDU via the one of the first access network, the second access network, or the first and second access networks.

3. 1. A method implemented in a wireless transmit / receive unit (WTRU), comprising: transmitting, to a first network element, first information indicating one of a request to establish a multi-access protocol data unit (PDU) session or a request to modify a multi-access PDU session; receiving, via a second network element, second information indicating a response to one of the request to establish a multi-access PDU session or the request to modify the multi-access PDU session; determining to transmit or receive a PDU associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks based on rules for a redundancy steering mode and the first value of the plurality of metrics of a first access network and the second value of the plurality of metrics of a second access network satisfying respective conditions of the rules; and performing one of transmitting and receiving the PDU via the first access network, the second access network, or the one of the first and second access networks.

4. 1. A method implemented in a wireless transmit / receive unit (WTRU), comprising: transmitting, to a first network element, first information indicating one of a request to establish a multi-access protocol data unit (PDU) session or a request to modify a multi-access PDU session, and one or more redundancy steering mode capabilities of the WTRU; receiving, via a second network element, second information indicating a response to one of a request to establish a multi-access PDU session or a request to modify a multi-access PDU session, and one or more rules for a redundancy steering mode including the rule; determining, based on one of the rules and the first value of the plurality of metrics of a first access network and the second value of the plurality of metrics of a second access network satisfying a respective condition of the rule, to transmit or receive a PDU associated with the multi-access PDU session via (i) the first access network, (ii) the second access network, or (iii) one of the first and second access networks; and performing one of transmitting and receiving the PDU via the first access network, the second access network, or the one of the first and second access networks.

5. 1. A wireless transmit / receive unit (WTRU) comprising a circuit comprising a transmitter, a receiver, a processor, and a memory, receiving third information indicating that traffic steering is supported via the second network element during a registration procedure; Sending first information to a first network element indicating one of a request to establish a multi-access protocol data unit (PDU) session or a request to modify a multi-access PDU session; receiving, via a second network element, second information indicating a response to one of the request to establish a multi-access PDU session or the request to modify the multi-access PDU session; determining first values ​​of a plurality of metrics for a first access network; determining second values ​​of the plurality of metrics for a second access network; determining, based on rules for a redundancy steering mode and the first and second values ​​of the plurality of metrics satisfying respective conditions of the rules, to transmit PDUs associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks; The WTRU is configured to transmit the PDU via the one of the first access network, the second access network, or the first and second access networks.

6. 1. A wireless transmit / receive unit (WTRU) comprising a circuit comprising a transmitter, a receiver, a processor, and a memory, Sending first information to a first network element indicating one of a request to establish a multi-access protocol data unit (PDU) session or a request to modify a multi-access PDU session; receiving, via a second network element, second information indicating a response to one of the request to establish a multi-access PDU session or the request to modify the multi-access PDU session; determining first values ​​of a plurality of metrics for a first access network; determining second values ​​of the plurality of metrics for a second access network; determining, based on rules for a redundancy steering mode and the first and second values ​​of the plurality of metrics satisfying respective conditions of the rules, to receive PDUs associated with the multi-access PDU session via one of (i) the first access network, (ii) the second access network, or (iii) the first and second access networks; The WTRU is configured to receive the PDU via the one of the first access network, the second access network, or the first and second access networks.

7. The method according to at least one of claims 1 to 4 or the WTRU according to at least one of claims 5 or 6, wherein the PDU is a PDU of an SDF associated with the multi-access PDU session.

8. 8. The method of claim 7 or the WTRU of claim 7, wherein, based on the rule, a state transition of the redundancy steering mode from inactive to active is performed on a condition that only a single access network of the first and second access networks cannot meet the requirements of the SDF.

9. 9. The method according to claim 7 or 8 or the WTRU according to claim 7 or 8, wherein, based on the rule, a state transition from active to inactive of the redundancy steering mode is performed on the condition that only a single access network among the first and second access networks can meet the requirements of the SDF.

10. A method according to at least one of claims 7 to 9 or a WTRU according to at least one of claims 7 to 9, wherein information indicating a duration of the state of the redundant steering mode is received from the network.

11. The method of claim 10 or the WTRU of claim 10, wherein information indicating whether the first or second access network should be used is received during the duration.

12. The method of claim 10 or the WTRU of claim 10, wherein measurements in any of the first and second access networks that have been removed are paused for the duration.

13. The method according to claim 10 or the WTRU according to claim 10, wherein the WTRU transitions to an IDLE mode on the access that is removed for the duration.

14. A method according to at least one of claims 1 to 3 and 7 to 13 or a WTRU according to at least one of claims 5 to 13, wherein the first information indicates one or more redundant steering mode capabilities of the WTRU, and the second information indicates one or more rules for a redundant steering mode including the rule.

15. The method of at least one of claims 1 to 4 and 7 to 14 or the WTRU of at least one of claims 5 to 14, wherein the plurality of metric network elements are access and mobility management functions.

16. The method according to at least one of claims 1 to 4 and 7 to 15 or the WTRU according to at least one of claims 5 to 15, wherein the second network element is a base station.

17. The method of at least one of claims 1 to 4 and 7 to 16 or the WTRU of at least one of claims 5 to 16, wherein the second network element is a base station associated with the first access network, the second access network, or a second access network different from the first of the first and second access networks.

18. The method of at least one of claims 1 to 4 and 7 to 17 or the WTRU of at least one of claims 5 to 17, wherein the plurality of metrics includes any two of the following: packet loss rate, delay, delay variability, and load.

19. The method of at least one of claims 4 and 7 to 18 or the WTRU of at least one of claims 7 to 18, wherein the one or more rules for a redundant steering mode include information indicating that an initial state of the redundant steering mode is one of active and inactive.

20. 20. The method of claim 19 or the WTRU of claim 19, wherein an initial PDU transmission of the SDF is transmitted via the first access network, the second access network, or the one of the first and second access networks based on the initial state of the redundancy steering mode being one of active and inactive.

21. The method according to at least one of claims 1 to 4 and 7 to 21 or the WTRU according to at least one of claims 5 to 21, wherein the one or more rules include information indicating a measurement configuration for the plurality of metrics.

22. A WTRU as described in at least one of claims 5 to 21, wherein the circuit is configured to expect to receive information indicating at least one rule for a redundancy steering mode based on transmitting the first information indicating the one or more redundancy steering mode capabilities of the WTRU.

23. A method according to at least one of claims 1 to 4 and 7 to 21, comprising expecting to receive information indicating at least one rule for a redundancy steering mode based on transmitting the first information indicating the one or more redundancy steering mode capabilities of the WTRU.

24. The method according to at least one of claims 1 to 4 and 7 to 23, comprising receiving, via the second network element during a registration procedure, third information indicating that traffic steering is supported.

25. determining to transmit a PDU, determining to transmit PDUs via the first and second access networks based on the rules, the first and second values ​​of the plurality of metrics satisfying respective conditions of the rules, and the rules indicating that PDU duplication for the redundancy steering mode is inactive; transmitting the PDU, The method according to at least one of claims 1 to 4 and 7 to 23, comprising transmitting the PDU based on the indicated PDU duplication.

26. The circuitry configured to determine whether to transmit (or receive) a PDU, the circuitry configured to determine to transmit PDUs via the first and second access networks based on the rules, the first and second values ​​of the plurality of metrics satisfying respective conditions of the rules, and the rules indicating that PDU duplication for the redundancy steering mode is inactive; the circuitry configured to transmit the PDU, The WTRU of at least one of claims 5 to 23, comprising the circuitry configured to transmit the PDU based on the indicated PDU duplication.

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