Defining multi-access steering, switching and splitting functionalities with backward compatibility

Abstract

A method performed by a user equipment is provided. The method includes determining that access traffic steering, switching and splitting (ATSSS) is supported by a network with which the UE is registered, and sending to the network information indicating ATSSS capabilities of the UE. The information is structured in an information element including a field set to indicate ATSSS steering functionalities and steering modes supported by the UE, and including a bit outside of the field that is set to indicate whether the UE supports ATSSS low layer functionality with only active-standby steering mode. The method includes receiving from the network one or more ATSSS rules determined by the network based on the ATSSS supported by the network and the ATSSS capabilities of the UE. And the method includes steering, splitting and / or switching traffic for a protocol data unit session based on the one or more ATSSS rules.

Description

DEFINING MULTI-ACCESS STEERING, SWITCHING AND SPLITTING FUNCTIONALITIES WITH BACKWARD COMPATIBILITY TECHNOLOGICAL FIELD

[0001] The present disclosure relates generally to telecommunications and, in particular, to access traffic steering, switching and splitting across multiple access networks in a telecommunications system.BACKGROUND

[0002] A telecommunications system can be seen as a facility that enables communication sessions between two or more entities such as user terminals, base stations and / or other nodes by providing carriers between the various entities involved in the communications path. A telecommunications system can be provided for example by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, video, electronic mail (email), text message, multimedia and / or content data and so on. Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

[0003] In a wireless telecommunications system, at least a part of a communication session between at least two stations occurs over a wireless link. Examples of wireless telecommunications systems comprise public land mobile networks (PLMN), satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). Some wireless systems can be divided into cells, and are therefore often referred to as cellular systems.

[0004] A user can access the telecommunications system by means of an appropriate communication device or terminal. A communication device of a user may be referred to as user equipment (UE) or user device. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other users. The communication device may access a carrier provided by a station, for example a base station of a cell, and transmit and / or receive communications on the carrier.

[0005] The telecommunications system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the communication system are permitted to do and how operations should be achieved. Communication protocols and / or parameters which shall be used for connection of the various entities are also typically defined. One example of a telecommunications system is the Universal Mobile Telecommunications System (UMTS). Other examples of telecommunications systems are Long-Term Evolution (LTE), LTE Advanced and the so-called 5G or New Radio (NR) networks. NR is being standardized by the 3rd Generation Partnership Project (3GPP).BRIEF SUMMARY

[0006] Example implementations of the present disclosure are directed to telecommunications and, in particular, to access traffic steering, switching and splitting across multiple access networks in a telecommunications system. The present disclosure includes, without limitation, the following example implementations.

[0007] Some example implementations provide an apparatus comprising: at least one processor; and at least one memory storing instructions of a user equipment (UE), the instructions when executed by the at least one processor causing the apparatus to perform operations, the operations comprising: determining that access traffic steering, switching and splitting (ATSSS) is supported by a network with which the UE is registered; sending to the network information indicating ATSSS capabilities of the UE, wherein the information is structured in an information element (IE) including a field set to indicate ATSSS steering functionalities and steering modes (ATSSS-ST) supported by the UE, and including a bit outside of the field that is set to indicate whether the UE supports ATSSS low layer (ATSSS-LL) functionality with only activestandby steering mode (ATSSS-LL-AS); receiving from the network one or more ATSSS rules determined by the network based on the ATSSS supported by the network and the ATSSS capabilities of the UE; and at least one of steering, splitting or switching traffic for a protocol data unit (PDU) session based on the one or more ATSSS rules.

[0008] Some example implementations provide a method performed by a user equipment (UE), the method comprising: determining that access traffic steering, switching and splitting (ATSSS) is supported by a network with which the UE is registered; sending to the network information indicating ATSSS capabilities of the UE, wherein the information is structured in an information element (IE) including a field set to indicate ATSSS steering functionalities and steering modes (ATSSS-ST) supported by the UE, and including a bit outside of the field that is set to indicate whether the UE supports ATSSS low layer (ATSSS-LL) functionality with only active-standby steering mode (ATSSS-LL-AS); receiving from the network one or more ATSSS rules determined by the network based on the ATSSS supported by the network and the ATSSS capabilities of the UE; and at least one of steering, splitting or switching traffic for a protocol data unit (PDU) session based on the one or more ATSSS rules.

[0009] Some example implementations provide an apparatus comprising: at least one processor; and at least one memory storing instructions that when executed by the at least one processor causing the apparatus to perform operations, the operations comprising: receiving from a user equipment (UE) information indicating access traffic steering, switching and splitting (ATSSS) capabilities of the UE, wherein the information is structured in an information element (IE) including a field set to indicate ATSSS steering functionalities and steering modes (ATSSS-ST) supported by the UE, and including a bit outside of the field that is set to indicate whether the UE supports ATSSS low layer (ATSSS-LL) functionality with only active-standby steering mode (ATSSS-LL-AS); selecting an ATSSS steering functionality and steeringmode based on ATSSS supported by the network and the ATSSS capabilities of the UE; and sending one or more ATSSS rules for the ATSSS steering functionality and steering mode to the UE for the UE to at least one of steer, split or switch traffic for a protocol data unit (PDU) session based on the one or more ATSSS rules.

[0010] Some example implementations provide a method comprising: receiving from a user equipment (UE) information indicating access traffic steering, switching and splitting (ATSSS) capabilities of the UE, wherein the information is structured in an information element (IE) including a field set to indicate ATSSS steering functionalities and steering modes (ATSSS-ST) supported by the UE, and including a bit outside of the field that is set to indicate whether the UE supports ATSSS low layer (ATSSS-LL) functionality with only active-standby steering mode (ATSSS-LL-AS); selecting an ATSSS steering functionality and steering mode based on ATSSS supported by the network and the ATSSS capabilities of the UE; and sending one or more ATSSS rules for the ATSSS steering functionality and steering mode to the UE for the UE to at least one of steer, split or switch traffic for a protocol data unit (PDU) session based on the one or more ATSSS rules.

[0011] These and other features, aspects, and advantages of the present disclosure will be apparent from a reading of the following detailed description together with the accompanying figures, which are briefly described below. The present disclosure includes any combination of two, three, four or more features or elements set forth in this disclosure, regardless of whether such features or elements are expressly combined or otherwise recited in a specific example implementation described herein. The present disclosure is intended to be read holistically such that any separable features or elements of the disclosure, in any of its aspects and example implementations, should be viewed as combinable unless the context of the disclosure clearly dictates otherwise.

[0012] It will therefore be appreciated that this Brief Summary is provided merely for purposes of summarizing some example implementations so as to provide a basic understanding of some aspects of the disclosure. Accordingly, it will be appreciated that the above described example implementations are merely examples and should not be construed to narrow the scope or spirit of the disclosure in any way. Other example implementations, aspects and advantages will become apparent from the following detailed description taken in conjunction with the accompanying figures which illustrate, by way of example, the principles of some described example implementations.BRIEF DESCRIPTION OF THE FIGURE(S)

[0013] Having thus described example implementations of the disclosure in general terms, reference will now be made to the accompanying figures, which are not necessarily drawn to scale, and wherein:

[0014] FIG. 1 illustrates a telecommunications system that includes one or more public land mobile networks (PLMNs) coupled to one or more external data networks, according to some example implementations of the present disclosure;

[0015] FIG. 2 illustrates a deployment of a PLMN, according to some example implementations;

[0016] FIG. 3 illustrates a 5G session management capability information element that includes a field set to indicate access traffic steering, switching and splitting (ATSSS) steering functionalities and steering modes (ATSSS-ST) supported by a user equipment (UE);

[0017] FIGS. 4A, 4B and 4C illustrate a session management capability information element including the field set to indicate ATSSS-ST supported by the UE, and at least one bit outside the field that is set to indicate whether the UE supports at least one particular ATSSS steering functionality and steering mode, according to various example implementations;

[0018] FIGS. 5 and 6 are signaling charts of protocol data unit (PDU) session establishment procedures including signaling ATSSS capabilities of a UE, and selection of an ATSSS steering functionality and steering mode for the PDU session, according to various example implementations;

[0019] FIG. 7 is a signaling chart of PDU session establishment and PDU session modification procedures including signaling ATSSS capabilities of a UE, and selection of an ATSSS steering functionality and steering mode for the PDU session, according to some example implementations;

[0020] FIG. 8 is a flowchart illustrating various steps in a method performed by a UE, according to various example implementations;

[0021] FIGS. 9A, 9B and 9C are flowcharts illustrating various steps in a method according to various example implementations; and

[0022] FIG. 10 illustrates an apparatus according to some example implementations.DETAILED DESCRIPTION

[0023] Some implementations of the present disclosure will now be described more fully hereinafter with reference to the accompanying figures, in which some, but not all implementations of the disclosure are shown. Indeed, various implementations of the disclosure may be embodied in many different forms and should not be construed as limited to the implementations set forth herein; rather, these example implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like reference numerals refer to like elements throughout.

[0024] Unless specified otherwise or clear from context, references to first, second or the like should not be construed to imply a particular order. A feature described as being above another feature (unless specified otherwise or clear from context) may instead be below, and vice versa; and similarly, features described as being to the left of another feature else may instead be to the right, and vice versa. Also, while reference may be made herein to quantitative measures, values, geometric relationships or the like, unless otherwise stated, any one or more if not all of these may be absolute or approximate to account for acceptable variations that may occur, such as those due to engineering tolerances or the like.

[0025] As used herein, unless specified otherwise or clear from context, the "or” of a set of operands is the "inclusive or” and thereby true if and only if one or more of the operands is true, as opposed to the "exclusive or” which is false when all of the operands are true. Thus, for example, "[A] or [B]” is true if [A] is true, or if [B] is true, or if both [A] and [B] are true. Further, the articles "a” and "an” mean "one or more,” unless specified otherwise or clear from context to be directed to a singular form. Furthermore, it should be understood that unless otherwise specified, the terms "data,” "content,” "digital content,” "information,” and similar terms may be at times used interchangeably. The term "network” may refer to a group of interconnected computers including clients and servers; and within a network, these computers may be interconnected directly or indirectly by various means including via one or more switches, routers, gateways, access points or the like.

[0026] The present disclosure discusses systems and architectures that, while specific terms may be used, are broadly applicable across various technologies. For instance, while the present disclosure may reference technologies from 3GPP such as Global System for Mobile Communications (GSM), UMTS, LTE, LTE Advanced, 5G NR, 5G Advanced, and 6G, the present disclosure is equally relevant to non-3GPP technologies like IEEE 802, Bluetooth, and Bluetooth Low Energy. Example implementations of the present disclosure described herein also mention public land mobile networks (PLMNs) and mobile network operators (MNOs), but example implementations are similarly applicable to standalone non-public networks (SNPNs) and the private entities operating these networks. Furthermore, although some examples and figures focus on radio access networks (RANs) and 3GPP access, example implementations are applicable to any type of network access. This includes not only 5G or 6G 3GPP access but also non-3GPP access, such as wireline access, untrusted non-3GPP access, and trusted non-3GPP access using wireless access gateway function (W-AGF), non-3GPP interworking function (N3IWF), or trusted non-3GPP gateway function (TNGF) to connect to a 5G or 6G core network.

[0027] Further, as used in this application, the term "circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry); (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that worktogether to cause an apparatus, such as a mobile phone or server, to perform various functions); or (c) hardware circuit(s) and / or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0028] The above definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0029] FIG. 1 illustrates a telecommunications system 100 according to various example implementations of the present disclosure. The telecommunications system generally includes one or more telecommunications networks. As shown, for example, the system includes one or morePLMNs 102 coupled to one or more other external data networks (DNs) 104 - notably including a wide area network (WAN) such as the Internet. As will be appreciated, a PLMN may be deployed in a number of different manners. Some deployments of 4G LTE and 5G NR in particular are considered standalone (SA) deployments. Other deployments combine 4G LTE and 5G technologies, and are referred to as non-standalone (NSA) deployments.

[0030] Each of the PLMNs 102 includes a core network (CN) 106 backbone, such as the Evolved Packet Core (EPC) of 4G LTE, the 5G core network (5GC) (at times referred to as the NGC) of 5G NR, and the 6G core network (6GC) of 6G; and each of the core networks and the Internet are coupled to one or more RANs 108, air interfaces or the like that implement one or more radio access technologies (RATs).Examples of these RANs include the evolved UMTS terrestrial radio access network (E-UTRAN) of 4G LTE, the next generation (NG) radio access network (NG-RAN) of 5G NR, and the 6G RAN. As used herein, a "network device” refers to any suitable device at a network side of a telecommunications network. Examples of suitable network devices are described in greater detail below.

[0031] Examples of RATs include 3GPP radio access technologies such as GSM, CDMA2000 1xEV-DO (HRPD), CDMA2000 1x (1xRTT), UTRA, E-UTRA, 5G NR, 5G Advanced, and 6G. Other examples of RATs include IEEE 802 technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.15 (including 802.15.1 (WPAN / Bluetooth), 802.15.4 (Zigbee) and 802.15.6 (WBAN)), Bluetooth, Bluetooth Low Energy (BLE), ultra wideband (UWB), and the like. Generally, a RAT may refer to any 2G, 3G, 4G, 5G, 6G or higher generation RAT and their different versions, as well as to any other RAT that may be arranged to interwork with such a mobile communication technology to provide access to the CN 106 of a MNO.

[0032] The telecommunications system 100 also includes one or more radio units that may be varyingly known as user equipment (UE) 110, terminal device, terminal equipment, mobile station or the like. The UE is generally a device configured to communicate with a network device or a further UE in a telecommunications network. The UE may be a portable computer (e.g., laptop, notebook, tablet computer), mobile phone (e.g., cell phone, smartphone), wearable computer (e.g., smartwatch), or the like. In other examples, the UE may be an Internet of things (loT) device, an industrial loT (lloT device), a vehicle equipped with a vehicle-to-everything (V2X) communication technology, or the like. In some examples, as referenced by 3GPP, the UE may be a narrowband loT (NB-loT) device, an enhanced machine-type communication (eMTC) device, a reduced capability (RedCap) device, an ambient loT device, or the like.

[0033] In operation, these UEs 110 may connect to one or more of the RANs 108 according to their particular RATs to thereby access a particular CN 106 of a PLMN 102, or to access one or more of the external data networks 104 (e.g., the Internet). The external data network may provide Internet access, operator services, 3rd party services, etc. For example, the International Telecommunication Union (ITU) has classified 5G mobile network services into three categories: enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine type communications (mMTC) or massive internet of things (MIoT).

[0034] In various examples, a RAN 108 may be configured as one or more macrocells, microcells, picocells, femtocells or the like. The RAN may generally include one or more RAN nodes that interact with UEs 110. In various examples, a RAN node may be referred to as a base station (BS), access point (AP), base transceiver station (BTS), Node B (NB), evolved NB (eNB), macro BS, NB (MNB) or eNB (MeNB), home BS, NB (HNB) or eNB (HeNB), next generation NB (gNB), enhanced gNB (en-gNB), next generation eNB (ng-eNB), 6G NB (6g NB), or the like. The term 'gNB' in 5G NR may correspond to the eNB in 4G LTE. Also, a NG-RAN node may refer to a gNB or a ng-eNB. And unless otherwise specified, a gNB in 5G NR or a 6gNB in 6G may at times be more generally referred to as a (6)gNB or more simply a gNB.

[0035] The RAN 108 may include some type of network controlling / governing entity responsible for control of the RAN nodes. The network controlling / governing entity and RAN node may be separate or integrated into a single apparatus. The network controlling / governing entity may include processing circuity configured to carry out various management functions, etc. The processing circuity may be associated with a memory, computer-readable storage medium or database for maintaining information required in the management functions.

[0036] FIG. 2 illustrates a deployment of a PLMN 102, such as 4G LTE, 5G NR or 6G deployment. As shown, the RAN 108 (e.g., E-UTRAN, NG-RAN, 6G RAN) includes one or more RAN nodes 202 configured to connect one or more UEs 110 to the RAN to thereby access the CN 106 (e.g., EPC, 5GC, 6GC). In 5GNR, the NG-RAN and 5GC are at times collectively referred to as the 5G system (5GS). Similarly, in 6G, the 6G RAN and 6GC may at times be collectively referred to as the 6G system (6GS).

[0037] In some deployments, operations of a gNB or other a RAN node 202 may be distributed or functionally split into components including one or more remote radio head (RRHs) or radio units (RUs), and a baseband unit (BBU); and in some architectures, the BBU may be split into a central / centralized unit (CU) (central node) and a distributed unit (DU) (distributed node). The CU may be, for example, a server, host or node. In some architectures, the RRH / RU and DU may be collocated. It is also possible that node operations may be distributed among a plurality of servers, hosts or nodes.

[0038] It should also be understood that the distribution of work between core network operations and RAN node operations may vary depending on implementation. A 5G or 6G network architecture, for example, may be based on a so-called CU-DU split. One gNB-CU (a CU) may control one or more gNB-DUs (DUs). The gNB-CU may control a plurality of spatially separated gNB-DUs, acting at least as transmit / receive (Tx / Rx) nodes. In some example implementations, however, the gNB-DUs may include, for example, a radio link control (RLC), medium access control (MAC) layer and a physical (PHY) layer, whereas the gNB-CU may include the layers above the RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RRC), and an internet protocol (IP) layer. Other functional splits are also possible. It is considered that skilled person is familiar with the open systems interconnection (OSI) model and the functionalities within each layer.

[0039] The CN 106 may include a number of network functions (NFs) divided between the control plane (CP) and the user plane (UP). In particular, for example, the CN may include, for example, NFs for mobility management (MM) 204 (at times referred to as a MM NF) and session management (SM) 206 (at times referred to as a SM NF), as well as a user plane function (UPF) 208. The MM may be, for example, a mobility management entity (MME) in the EPC, an access and mobility management function (AMF) in the 5GC, or a 6G MM in the 6GC. Similarly, the SM may be, for example, a serving gateway (SGW) control plane function (SGW-C) and / or packet data network gateway (PGW) control plane function (PGW-C) in the EPC, a session management function (SMF) in the 5GC, or a 6G SM in the 6GC. In the EPC, the UPF 308 may be a SGW user plane function (SGW-U) and / or PGW user plane function (PGW-U). Other examples of suitable NFs include a policy and charging function (PCF) 210 (or a policy and charging rules function (PCRF) or the like in the EPC).

[0040] In 3GPP, access traffic steering, switching and splitting (ATSSS) enables a multi-access (MA) protocol data unit (PDU) connectivity service in which data traffic may be concurrently transported between the UE 110 and a DN 104 across two (or more) access networks (e.g., one 3GPP access network and one non-3GPP access network, two 3GPP access networks) and two independent tunnels between the UPF 208 and the RAN 108 / access network (AN), in some cases, the actual traffic steering in both the UE andUPF may be performed by steering functionalities and steering modes. A single UPF 208 may be used as a termination point of both access legs (i.e., terminate the MA PDU session).

[0041] The SM 206 may create ATSSS rules and N4 rules based on policy and charging control (PCC) rules provided by the PCF 210. The SM may send the ATSSS rules to the UE 110 via a non-access stratum (NAS), and the SM may send the N4 rules to the UPF 208 via an N4 interface. The ATSSS rules may include traffic descriptors and information about steering functionality(ies) and steering modes to be applied by the UE for uplink (UL) traffic. The N4 rules may include packet detection rules (PDRs), forwarding action rules (FARs) and multi- access rules (MARs) for the UPF to perform traffic steering for downlink (DL) traffic for each of the multiple accesses.

[0042] Introduced in Release 16. 3GPP defined two types of steering functionalities, namely. ATSSS low layer (ATSSS-LL) to handle any type of traffic and multipath transmission control protocol (MPTCP) designed to handle transmission control protocol (TCP) traffic. In Release 18, 3GPP added another steering functionality, namely multipath QUIC (MPQUIC), designed to handle user datagram protocol (UDP) traffic (the functionality at times referred to as MPQUIC-UDP). The ATSSS-LL functionality may be supported with any steering mode, or with only an active-standby steering mode (ATSSS-LL-AS). The MPTCP and MPQUIC functionalities may be supported with any steering mode, or with only the active standby steering mode.

[0043] More steering functionalities are under consideration for 3GPP Release 19, including variants of MPQUIC designed to handle IP traffic (MPQUiC-IP) and Ethernet traffic (MPQUiC-E). Another variant of MPQUIC (MPQUIC-TCP) is designed to handle TCP traffic. Incorporating these or other additional steering functionalities, however, raises a number of issues to be resolved.

[0044] As currently specified, a UE 110 signals UE capability related to PDU session management to the SM 206, and this UE capability includes information indicating ATSSS capabilities of the UE. In particular, the UE signals the UE capability related to PDU session management in an information element (IE) included in certain session management messages, such as a PDU session establishment, request or a PDU session modification request. In 5G NR, this IE is referred to as a 5G session management (5GSM) capability IE. The 5GSM IE is coded as shown in FIG. 3, and includes a field (ATSSS-ST) with four bits set to indicate the 5GSM capability of ATSSS steering functionalities and steering modes.

[0045] The ATSSS-ST field of the 5GSM capability IE may be set as follows:0 0 0 0 ATSSS not supported0 0 0 1 ATSSS Low-Layer functionality with any steering mode allowed for ATSSS-LL supported0 0 1 0 MPTCP functionality with any steering mode and ATSSS-LL functionality withonly active-standby steering mode supported0 0 1 1 MPTCP functionality with any steering mode and ATSSS-LL functionality with any steering mode allowed for ATSSS-LL supported0 1 0 0 MPQUIC functionality with any steering mode and ATSSS-LL functionality withonly active-standby steering mode supported0 1 0 1 MPQUIC functionality with any steering mode and ATSSS-LL functionality withany steering mode allowed for ATSSS-LL supported0 1 1 0 MPTCP functionality with any steering mode, MPQUIC functionality with any steering mode and ATSSS-LL functionality with only active-standby steering mode supported0 1 1 1 MPTCP functionality with any steering mode, MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode allowed for ATSSS-LL supported

[0046] As specified, all other values of the ATSSS-ST field are reserved, which prevents the ATSSS-ST field from being used to indicate support for any other ATSSS steering functionalities. The ATSSS-ST field therefore cannot be extended to add new values to indicate whether the UE supports MPQUIC-IP, MPQUIC-TCP and / or MPQUIC-E to be introduced in 3GPP Release 19. The same problem actually already exists in Release 18 where the ATSSS-ST field in Release 17 was extended to indicate whether the UE supports MPQUIC (MPQUIC -UDP) even though the unused values in Release 17 were designated as reserved.

[0047] Even if the remaining values were available, the remaining values would be insufficient to cover the combinations of ATSSS steering functionalities and steering modes that result when MPQUIC-IP, MPQUIC-TCP and / or MPQUIC-E are included. As indicated above, the ATSSS-ST field indicates ATSSS capabilities of the UE as different combinations of ATSSS steering functionalities and steering modes, and not as discrete bits for respective ones of the ATSSS steering functionalities and steering modes. For example, the ATSSS-ST field set with the value 0011 indicates the ATSSS-LL and MPTCP (each with any steering mode) are supported. As another example, the ATSSS-ST field set with the value 0101 indicates ATSSS-LL and MPQUIC-UDP (each with any steering mode) are supported. And as yet another example, the ATSSS-ST field set with the value 0111 indicates ATSSS-LL, MPTCP and MPQUIC-UDP (each with any steering mode) are supported.

[0048] The manner of coding ATSSS capabilities of the UE 110 in the ATSSS-ST field is inefficient because of the number of values needed to cover all combinations of ATSSS steering functionalities and steering modes, especially considering the addition of MPQUIC-IP, MPQUIC-TCP and / or MPQUIC-E. The manner of coding also does not enable backward compatibility as any newly added values would not be understood by a legacy receiver, which would result in the receiver ignoring the indicated ATSSS capability. As an example, consider a Release 19 UE that indicates its ATSSS capabilities in the ATSSS-ST field set with anew value set to indicate ATSSS-LL, MPTCP and MPQUIC-IP are supported. When the 5GSM capability IE including the ATSSS-ST field is received by a legacy (Release 18) network (e.g., SM 206), the network will ignore the entire ATSSS capability because the network does not understand the new value, even though the network may otherwise support ATSSS-LL and MPTCP.

[0049] It has also been decided to keep ATSSS-LL with only active-standby steering mode (ATSSS-LL-AS) as a minimum common capability among the ATSSS steering functionalities and steering modes. This means that both the UE 110 and the network (e.g., SM 206) shall fall back to ATSSS-LL-AS when no other ATSSS steering functionality and steering mode is supported by both the UE and the network. For example, if the UE indicates that its ATSSS capabilities include MPTCP and ATSSS-LL-AS, and the network supports only ATSSS-LL for a data network name (DNN), the network may accept to establish a MA PDU session with ATSSS-LL-AS. But this behavior is currently not supported by the current manner of coding ATSSS capabilities of the UE.

[0050] Even further, it has been decided to introduce an option in which MPQUIC-IP may be supported as a standalone ATSSS capability without also including ATSSS-LL. The current manner of coding ATSSS capabilities of the UE also do not support indicating support for another ATSSS steering functionality and steering mode not in combination with ATSSS-LL.

[0051] In view of the foregoing, example implementations of the present disclosure provide a solution in which the manner of indicating ATSSS capabilities of a UE 110 is restructured. Instead of coding the ATSSS steering functionalities and steering modes by values that indicate combinations of ATSSS steering functionalities and steering modes, whether the UE supports each of a number of ATSSS steering functionality and steering mode may be indicated by one or more separate bits.

[0052] Information indicating the ATSSS capabilities of the UE 110 may be structured in an IE (e.g., 5GSM capability IE) including the ATSSS-ST field set to indicate ATSSS-ST supported by the UE. In some examples, the ATSSS-ST field may be set to indicate whether the UE supports either or both ATSSS-LL functionality with any steering mode, or MPTCP functionality (with any steering mode). The IE may also include one or more bits outside the field that are set to indicate whether the UE supports one or more of ATSSS-LL-AS, MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP and / or MPQUIC-E. The structure of the information indicating the ATSSS capabilities may enable a larger number of combinations of ATSSS steering functionalities and steering modes, as well as backward compatibility without using the reserved bits of the ATSSS-ST field.

[0053] As indicated, the bit(s) outside the ATSSS-ST field may include a bit that is set to indicate whether the UE 110 supports ATSSS-LL-AS, which as indicated above may be designated as the minimum common capability among the ATSSS steering functionalities and steering modes. This bit may at times be referred to as the ATSSS-LL-AS bit. The minimum common capability may therefore be indicated outside of the ATSSS-ST field, rather than in combination with other ATSSS steering functionalities and steering modes inthe ATSSS-ST field. The ATSSS-LL-AS bit may enable backward compatibility. In this regard, a Release 19 UE that supports only MPQUIC-IP and ATSSS-LL-AS may set the ATSSS-LL-AS bit to indicate ATSSS-LL-AS is supported. When the Release 19 UE communicates with a Release 18 network (e.g., SM 206) that does not support MPQUIC-IP, the network may interpret the ATSSS-LL-AS bit and proceed with only ATSSS-LL-AS.

[0054] Even further, indicating support for ATSSS-LL-AS separate from MPQUIC-IP also enables the option for the UE 110 to support MPQUIC-IP without also including ATSSS-LL.

[0055] FIGS. 4A, 4B and 4C illustrate a session management (SM) capability IE (e.g., 5GSM capability IE) including the field set to indicate ATSSS-ST supported by the UE, and at least one bit outside the field that is set to indicate whether the UE supports at least one particular ATSSS steering functionality and steering mode, according to various example implementations. As shown, the at least one bit may be set to indicate whether the UE supports one or more of ATSSS-LL-AS, MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP and / or MPQUIC-E. The figures illustrate particular combinations of bits in a particular order, although it should be understood that the SM capability IE may include another combination of bits and / or a different order of bits.

[0056] FIG. 4A illustrates a SM capability IE 400A (e.g., 5GSM capability IE) including the AT-SSS field 402 set to indicate ATSSS-ST supported by the UE 110, and an ATSSS-LL-AS bit 404 outside the ATSSS-ST field that is set to indicate whether the UE supports ATSSS-LL-AS, according to some example implementations. The ATSSS-LL-AS bit may be set to the value 0 to indicate ATSSS-LL-AS is not supported, and set to the value 1 to indicate ATSSS-LL-AS is supported.

[0057] In some examples, the SM capability IE shown in FIG. 4A may be used in 3GPP Release 17, which as indicated above includes support for ATSSS-LL and MPTCP functionalities. In some of these examples, the ATSSS-LL-AS bit may not be set by the UE 110. If the network receives the SM capability IE in which the ATSSS-ST field is set with a value that indicates ATSSS is not supported, and the ATSSS-LL-AS bit is set to indicate ATSSS-LL-AS is supported, the network may understand that the UE supports only ATSSS-LL-AS. And in that case, if the DNN configuration allows at least ATSSS-LL-AS, the network may ensure that the established PDU session has the capability of ATSSS-LL-AS in the DL and the UL. The network may otherwise ignore the value of the ATSSS-LL-AS bit.

[0058] FIG. 4B illustrates a SM capability IE 400B that further includes another bit 406 outside the ATSSS-ST field that is set to indicate whether the UE 110 supports MPQUIC (MPQUIC-UDP), according to some other example implementations. This MPQUIC bit may be set to the value 0 to indicate MPQUIC is not supported, and set to the value 1 to indicate MPQUIC is supported.

[0059] In some examples, the SM capability IE shown in FIG. 4B may be used in 3GPP Release 18, which as indicated above includes support for ATSSS-LL, MPTCP and MPQUIC functionalities. In some of these examples, the values of the ATSSS-ST field indicated above may be limited to the values 0000 to 0011,with the remaining values 0100 to 0111 being omitted. Also in some of these examples, the ATSSS-LL-AS bit may be checked by the network (e.g., SM 206) only when the ATSSS-ST field is set to indicate ATSSS is not supported, and the MPQUIC bit is set to indicate MPQUIC functionality with any steering mode is supported.

[0060] In the context of 3GPP Release 18, in some examples, the UE 110 may request to establish (or modify) a MA PDU session or if the UE requests to establish (or modify) a PDU session and the UE allows the network to upgrade the requested PDU session to an MA PDU session. If the UE has not set the bits of the ATSSS-ST field of the SM capability IE (of the PDU session establishment / modification request) to indicate ATSSS not supported, and the UE supports MPQUIC functionality with any steering mode, the UE may set the MPQUIC bit to indicate MPQUIC functionality with any steering mode supported. In this case, the value of the ATSSS-LL-AS bit may be ignored because the support of ATSSS-LL functionality may be obtained from the selected value inside the ATSSS-ST field.

[0061] If on the other hand the UE 110 has set the bits of the ATSSS-ST field of the SM capability IE to indicate ATSSS not supported, and the UE supports MPQUIC functionality with any steering mode and ATSSS-LL-AS, the UE may set the MPQUIC bit to indicate MPQUIC functionality with any steering mode is supported. The UE may also set the ATSSS-LL-AS bit to indicate ATSSS-LL-AS is supported.

[0062] In some cases in which the UE 110 has not set the bits of the ATSSS-ST field to indicate ATSSS not supported, the UE may set the bits of the ATSSS-ST field to indicate MPTCP functionality with any steering mode and ATSSS-LL-AS are supported. In other cases, the UE may set the bits of the ATSSS-ST field to indicate MPTCP functionality with any steering mode and ATSSS-LL functionality with any steering mode allowed for ATSSS-LL are supported. In some of these cases, if the DNN configuration does not allow for the MPTCP functionality with any steering mode and allows at least for ATSSS-LL-AS, the SM 206 may ensure that the established PDU session has the capability of ATSSS-LL-AS in the DL and the UL.Additionally, if the MPQUIC bit of the SM capability IE (of the PDU session establishment / modification request) is set to indicate MPQUIC functionality with any steering mode is supported, and the DNN configuration allows for the MPQUIC functionality with any steering mode, the SM 206 may ensure that the established PDU session also has the capability of MPQUIC with any steering mode in the DL and the UL.

[0063] In some cases in which the UE 110 has set the bits of the ATSSS-ST field to indicate ATSSS not supported, the UE may set the MPQUIC bit to indicate MPQUIC functionality with any steering mode is supported, and set the ATSSS-LL-AS bit to indicate ATSSS-LL-AS is supported. In some of these cases, if the DNN configuration allows for the MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality), but does not allow roundtrip time (RTT) measurement without using a performance measurement functionality (PMF) protocol, the SM 206 may ensure that the established PDU session has the capability of MPQUIC with anysteering mode and ATSSS-LL-AS, load balancing steering mode or priority based steering mode steering mode in the DL and MPQUIC with any steering mode and ATSSS-LL-AS in the UL.

[0064] Also in some cases in which the MPQUIC and ATSSS-LL-AS bits are set to indicate both are supported, if the DNN configuration allows for the MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) and allows RTT measurement without using the PMF protocol, the SM 206 may ensure that the established PDU session has the capability of MPQUIC with any steering mode and ATSSS-LL with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) in the DL and MPQUIC with any steering mode and ATSSS-LL-AS in the UL.

[0065] Even further, if the MPQUIC and ATSSS-LL-AS bits are set to indicate both are supported, and if the DNN configuration allows for the MPQUIC functionality with any steering mode and ATSSS-LL-AS, the SM 206 may ensure that the established PDU session has the capability of MPQUIC with any steering mode and ATSSS-LL-AS in the DL and the UL. If the DNN configuration does not allow for MPQUIC functionality with any steering mode and allows at least for ATSSS-LL-AS, the SM may ensure that the established PDU session has the capability of ATSSS-LL-AS in the DL and the UL.

[0066] FIG. 4C illustrates a SM capability IE 400C that further includes two further bits 408, 410 outside the ATSSS-ST field that is set to indicate whether the UE 110 supports respective ones of MPQUIC-IP and MPQUIC-E, according to some other example implementations. The MPQUIC-IP bit may be set to the value 0 to indicate MPQUIC-IP is not supported, and set to the value 1 to indicate MPQUIC-IP is supported. Likewise, the MPQUIC-E bit may be set to the value 0 to indicate MPQUIC-E is not supported, and set to the value 1 to indicate MPQUIC-E is supported.

[0067] In some examples, the SM capability IE shown in FIG. 4C may be used in 3GPP Release 19, which as indicated above may include support for ATSSS-LL, MPTCP, MPQUIC-UDP, MPQUIC-IP and MPQUIC-E functionalities. In some of these examples, the values of the ATSSS-ST field indicated above may be limited to the values 0000 to 0011, with the remaining values 0100 to 0111 being omitted. Also in some of these examples, the ATSSS-LL-AS bit may be checked by the network (e.g., SM 206) only when the bits of the ATSSS-ST field are set to indicate ATSSS not supported, and any one or more of the MPQUIC-UDP, MPQUIC-IP or MPQUIC-E bits are set to indicate the respective functionality(ies) with any steering mode are supported.

[0068] In the context of 3GPP Release 19, in some examples, the UE 110 may request to establish (or modify) a MA PDU session or if the UE requests to establish (or modify) a PDU session and the UE allows the network to upgrade the requested PDU session to an MA PDU session. If the UE has not set the bits of the ATSSS-ST field of the SM capability IE (of the PDU session establishment / modification request) to indicate ATSSS not supported, and the UE supports MPQUIC-UPD functionality with any steering mode, the UE may set the MPQUIC-UDP bit to indicate MPQUIC-UDP functionality with any steering modesupported. If the UE supports MPQUIC-IP and / or MPQUIC-E functionality with any steering mode, the UE may set the MPQUIC-IP bit and / or the MPQUIC-E bit to indicate the respective functionality (ies) with any steering mode supported. In any of these cases, the value of the ATSSS-LL-AS bit may be ignored because the support of ATSSS-LL functionality may be obtained from the selected value inside the ATSSS-ST field.

[0069] If on the other hand the UE 110 has set the bits of the ATSSS-ST field of the SM capability IE to indicate ATSSS not supported, and the UE supports MPQUIC-UDP functionality with any steering mode and ATSSS-LL-AS, the UE may set the MPQUIC-UDP bit to indicate MPQUIC-UDP functionality with any steering mode is supported. The UE may also set the ATSSS-LL-AS bit to indicate ATSSS-LL-AS is supported.

[0070] If the UE 110 has set the bits of the ATSSS-ST field of the SM capability IE to indicate ATSSS not supported, and the UE supports MPQUIC-IP functionality with any steering mode and ATSSS-LL-AS, the UE may set the MPQUIC-IP and ATSSS-LL-AS bits to indicate MPQUIC-IP functionality with any steering mode and ATSSS-LL-AS are supported. If the UE supports MPQUIC-IP functionality with any steering mode without any ATSSS-LL functionality, and the PDU session type is not set to " Ethernet.” the UE may set the MPQUIC-IP bit to indicate MPQUIC-IP functionality with any steering mode is supported, and set the ATSSS-LL-AS bit to indicate ATSSS-LL-AS is not supported.

[0071] If the UE 110 has set the bits of the ATSSS-ST field of the SM capability IE to indicate ATSSS not supported, and the UE supports MPQUIC-E functionality with any steering mode and ATSSS-LL-AS, the UE may set the MPQUIC-E and ATSSS-LL-AS bits to indicate MPQUIC-E functionality with any steering mode and ATSSS-LL-AS are supported.

[0072] In some cases in which the UE 110 has not set the bits of the ATSSS-ST field to indicate ATSSS not supported, the UE may set the bits of the ATSSS-ST field to indicate MPTCP functionality with any steering mode and ATSSS-LL-AS are supported. In other cases, the UE may set the bits of the ATSSS-ST field to indicate MPTCP functionality with any steering mode and ATSSS-LL functionality with any steering mode allowed for ATSSS-LL are supported. In some of these cases, if the DNN configuration does not allow for the MPTCP functionality with any steering mode and allows at least for ATSSS-LL-AS, the SM 206 may ensure that the established PDU session has the capability of ATSSS-LL-AS in the DL and the UL.Additionally, if the MPQUIC-UDP bit of the SM capability IE (of the PDU session establishment / modification request) is set to indicate MPQUIC-UDP functionality with any steering mode is supported, and the DNN configuration allows for the MPQUIC-UDP functionality with any steering mode, the SM 206 may ensure that the established PDU session also has the capability of MPQUIC-UDP with any steering mode in the DL and the UL.

[0073] In some cases in which the UE 110 has not set the bits of the ATSSS-ST field to indicate ATSSS not supported, the UE may set the MPQUIC-IP bit to indicate MPQUIC-IP functionality with any steering modeis supported. In some of these cases, if the DNN configuration allows for the MPQUIC-IP functionality with any steering mode, the SM 206 may ensure that the established PDU session also has the capability of MPQUIC-IP with any steering mode in the DL and the UL. Similarly, if the MPQUIC-E bit is set to indicate MPQUIC-E functionality with any steering mode is supported, and the DNN configuration allows for the MPQUIC-E functionality with any steering mode, the SM may ensure that the established PDU session also has the capability of MPQUIC-E with any steering mode in the DL and the UL.

[0074] In some cases in which the UE 110 has set the bits of the ATSSS-ST field to indicate ATSSS not supported, any one or more of the MPQUIC-UDP, MPQUIC-IP or MPQUIC-E bits may be set to indicate the respective MPQUIC functionality(ies) with any steering mode are supported, and the ATSSS-LL-AS bit may be set to indicate ATSSS-LL-AS is supported. In some of these cases, if the DNN configuration allows for one or more of the indicated MPQUIC functionality (ies) with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality), but does not allow RTT measurement without using the PMF protocol, the SM 206 may ensure that the established PDU session has the capability of the allowed MPQUIC functionality (ies) with any steering mode and ATSSS-LL-AS, load balancing steering mode or priority based steering mode steering mode in the DL and MPQUIC functionality (ies) with any steering mode and ATSSS-LL-AS in the UL.

[0075] Also in some cases in which the MPQUIC-UDP / IP / E and ATSSS-LL-AS bits are set to indicate MPQUIC functionality(ies) and ATSSS-LL-AS are supported, if the DNN configuration allows for one or more of the indicated MPQUIC functional ity (ies) with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) and allows RTT measurement without using the PMF protocol, the SM 206 may ensure that the established PDU session has the capability of the allowed MPQUIC functionality(ies) with any steering mode and ATSSS-LL with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) in the DL and the allowedMPQUIC functionality(ies) with any steering mode and ATSSS-LL-AS in the UL.

[0076] Further, if the MPQUIC-UDP / IP / E and ATSSS-LL-AS bits are set to indicate MPQUIC functionality(ies) and ATSSS-LL-AS are supported, and if the DNN configuration allows for one or more of the indicated MPQUIC functionality (ies) with any steering mode and ATSSS-LL-AS, the SM 206 may ensure that the established PDU session has the capability of the allowed MPQUIC functionality (ies) with any steering mode and ATSSS-LL-AS in the DL and the UL. If the DNN configuration does not allow for any of the indicated MPQUIC functionality(ies) with any steering mode and allows at least for ATSSS-LL-AS, the SM may ensure that the established PDU session has the capability of ATSSS-LL-AS in the DL and the UL.

[0077] Even further, in some cases in which the UE 110 has set the bits of the ATSSS-ST field to indicate ATSSS not supported, the MPQUIC-UDP, MPQUIC-E and ATSSS-LL-AS bits may be set to indicate the respective functionalities are not supported, and the MPQUIC-IP bit may be set to indicate the MPQUIC-IPfunctionality with any steering mode is supported. In these cases, if the DNN configuration allows for the MPQUIC-IP functionality with any steering mode, the SM 206 may ensure that the established PDU session has the capability of MPQUIC-IP with any steering mode in the DL and the UL.

[0078] According to some example implementations, the ATSSS capabilities of a UE 110 may be structured as indicated above in which supported ATSSS steering functionalities and steering modes may be indicated by respective bits in an IE. To further provide backward compatibility, some example implementations also provide a negotiation process between the UE and network (e.g., SM 206), such as during a PDU session establishment or PDU session modification procedure.

[0079] In some example implementations, during a PDU session establishment procedure, the UE 110 may provide information that indicates its ATSSS capabilities structured in a 5GSM capabilities IE, such as in the manner shown in FIG. 3. This version of the IE includes the ATSSS-ST field, but does not include the other bit(s) set to indicate whether the UE supports ATSSS-LL-AS, MPQUIC-UDP, MPQUIC-IP and / or MPQUIC-E. The UE may also provide an indication of UE support for the information structured in the IE according to example implementations, such as in the manner shown in FIG. 4A, 4B or 4C.

[0080] In some examples, the indication may be provided by a flag in a protocol configuration option (PCO) that indicates the UE 110 supports the coding of the ATSSS capabilities according to example implementations. In some examples, this coding may be referred to as a Release 19 coding of the ATSSS capabilities (as the coding supports ATSSS steering functionalities and steering modes introduced in Release 19), as compared to a Release 18 (or even Release 17) coding of the ATSSS capabilities. The indication that the UE supports the Release 19 may be an optional parameter which may be ignored by a Release 18 or earlier network (e.g., SM 206).

[0081] A Release 19 (or later) SM 206 may respond back to the UE 110 with information that indicates the network supports the Release 19 coding of the ATSSS capabilities. In some examples, the SM may send the information in a transfer of N1 and / or N2 information to the UE through the MM 204 (e.g., a Namf_ Communication_N1N2MessageTransfer). The UE may receive the information, and provide its ATSSS capabilities in the Release 19 coding, such as in a NAS SM transport to the MM which the MM may then provide to the SM (e.g., in a Nsmf_PDUSession_UpdateSMContext). The PDU session establishment may then proceed in a manner as specified by 3GPP.

[0082] In some other example implementations, the SM 206 may respond back to the UE 110 with the information that indicates the network supports the Release 19 coding of the ATSSS capabilities, and the information may be sent to the UE in a PDU session accept message. The UE may receive the information, and provide in a PDU session modification procedure its ATSSS capabilities in the Release 19 coding. The SM may provide a corresponding update of capabilities for the PDU session to the PCF 210, such as via SM policy association modification procedure. In some cases, the PCF may decide to update the PCC rules for the PDU session, and provide updated PCC rules to the SM. The SM may in turn create updatedATSSS rules and updated N4 rules based on the updated PCC rules, and provide the updated ATSSS rules and updated N4 rules to the UE and UPF 208.

[0083] To further illustrate some example implementations, FIG. 5 is a signaling chart 500 of a PDU session establishment procedure including signaling ATSSS capabilities of a UE, and selection of an ATSSS steering functionality and steering mode for the PDU session, according to some example implementations. As shown, a UE 110 may at step 501 send a PDU session establishment request to the SM 206. The PDU session establishment request may include an IE (e.g., 5GSM capabilities IE) with information that indicates ATSSS capabilities structured according to the Release 19 coding of the ATSSS capabilities. In this regard, the information that indicates the ATSSS capabilities may be structured in the ATSSS-ST field, and bit(s) outside the ATSSS-ST field including the ATSSS-LL-AS bit set to indicate whether the UE supports ATSSS-LL-AS.

[0084] The information that indicates the ATSSS capabilities indicates ATSSS steering functionality(ies) and steering modes supported by the UE 110. If the network (e.g., SM 206) supports the indicated ATSSS steering functionality (ies) and steering modes, the SM may at step 502 select an ATSSS steering functionality and steering mode based on the ATSSS supported by the network and the ATSSS capabilities of the UE. The SM may at step 503 send to the PCF 210 information that indicates the selected ATSSS steering functionality and steering mode. The PCF may determine PCC rules for the selected ATSSS steering functionality and steering mode, and the PCF may at step 504 send the PCC rules to the SM. The SM may create ATSSS rules (and N4 rules) based on the PCC rules. The SM may at step 505 send a PDU session accept message to the UE, and the PDU session accept message may include information that indicates the ATSSS rules.

[0085] If the network (e.g., SM 206) does not support the indicated ATSSS steering functionality(ies) and steering modes, the SM may at step 506 select the minimum common capability, i.e., ATSSS-LL-AS. The SM may at step 507 send to the PCF 210 information that indicates the selected ATSSS-LL-AS. The PCF may determine PCC rules for the selected ATSSS-LL-AS, and the PCF may at step 508 send the PCC rules to the SM. The SM may create ATSSS rules (and N4 rules) based on the PCC rules. The SM may at step 509 send a PDU session accept message to the UE, and the PDU session accept message may include information that indicates the ATSSS rules.

[0086] FIG. 6 is a signaling chart 600 of a PDU session establishment procedure including signaling ATSSS capabilities of a UE, and selection of an ATSSS steering functionality and steering mode for the PDU session, according to some example implementations. As shown, a UE 110 may at step 601 send a PDU session establishment request to a MM 204. The PDU session establishment request may include an IE (e.g., 5GSM capabilities IE) with information that indicates ATSSS capabilities structured according to the Release 18 coding of the ATSSS capabilities, such as shown in FIG. 3. The PDU session establishment request may also include an indication of UE support for the Release 19 coding of the ATSSS capabilities(the IE structured according to some example implementations). The MM may at step 602 send to the SM 206 the indication of UE support for the Release 19 coding of the ATSSS capabilities, such as in a request to create a SM context for the PDU session (Nsmf_PDUSession_CreateSMContext request).

[0087] If the SM 206 supports the Release 19 coding of the ATSSS capabilities, the SM may at steps 603, 604 send a NAS message to the UE through the MM 204, and the NAS message may include information that indicates network support for the Release 19 coding of the ATSSS capabilities.

[0088] The UE 110 may receive the information that indicates network support for the Release 19 coding, and the UE may at step 605 send a NAS SM message to the MM 204 that includes the UE's ATSSS capabilities in the Release 19 coding, such as shown in FIG. 4C. The MM may at step 606 send to the SM 206 the UE's ATSSS capabilities in the Release 19 coding. The PDU session establishment procedure may then continue in the manner as specified by 3GPP (from step 7 of the procedure as described in 3GPP TS 23.502, clause 4.3.2.2.1).

[0089] FIG. 7 is a signaling chart 700 of PDU session establishment and PDU session modification procedures including signaling ATSSS capabilities of a UE, and selection of an ATSSS steering functionality and steering mode for the PDU session, according to some example implementations. As shown, a UE 110 may at step 701 send a PDU session establishment request to a MM 204. The PDU session establishment request may include an IE (e.g., 5GSM capabilities IE) with information that indicates ATSSS capabilities structured according to the Release 18 coding of the ATSSS capabilities, such as shown in FIG. 3. The PDU session establishment request may also include an indication of UE support for the Release 19 coding of the ATSSS capabilities (the IE structured according to some example implementations). The MM may at step 702 send to the SM 206 the indication of UE support for the Release 19 coding of the ATSSS capabilities, such as in a request to create a SM context for the PDU session (Nsmf_PDUSession_CreateSMContext request).

[0090] If the SM 206 supports the Release 19 coding of the ATSSS capabilities, the SM may at steps 703, 704 send a NAS message to the UE through the MM 204, and the NAS message may include information that indicates network support for the Release 19 coding of the ATSSS capabilities. As shown, the NAS message may be sent in a PDU session accept message, which may include ATSSS rules for a ATSSS steering functionality and steering mode selected from the ATSSS capabilities structured according to the Release 18 coding.

[0091] The UE 110 may receive the information that indicates network support for the Release 19 coding, and the UE may at step 705 send to the MM 204 a PDU session modification request to initiate a PDU session modification procedure. In the PDU session modification request, the UE may include the UE's ATSSS capabilities in the Release 19 coding, such as shown in FIG. 4C. The MM may at step 706 send to the SM 206 a request to update the SM context for the PDU session, and the request may include the UE's ATSSS capabilities in the Release 19 coding.

[0092] The SM 206 may at step 707 send to the PCF 210 a SM policy association modification message to initiate a SM policy association update, and the SM policy association modification message may include the UE's ATSSS capabilities in the Release 19 coding. In some cases, the PCF may decide to update the PCC rules. The PCF may at step 708 provide updated PCC rules to the SM. The SM may create updated ATSSS rules and updated N4 rules based on the updated PCC rules, and the SM may at steps 709, 710 provide the updated ATSSS rules to the UE and UPF 208. The SM may also at step 710 provide the updated N4 rules (including PDRs, FARs and / or MARs) to the UPF.

[0093] FIG. 8 is a flowchart illustrating various steps in a method 800 performed by a user equipment (UE), according to various example implementations. The method includes determining that access traffic steering, switching and splitting (ATSSS) is supported by a network with which the UE is registered, as shown at block 802. The method includes sending to the network information indicating ATSSS capabilities of the UE, as shown at block 804. The information is structured in an information element (IE) including a field set to indicate ATSSS steering functionalities and steering modes (ATSSS-ST) supported by the UE, and including a bit outside of the field that is set to indicate whether the UE supports ATSSS low layer (ATSSS-LL) functionality with only active-standby steering mode (ATSSS-LL-AS). The method includes receiving from the network one or more ATSSS rules determined by the network based on the ATSSS supported by the network and the ATSSS capabilities of the UE, as shown at block 806. And the method includes at least one of steering, splitting or switching at block 808 traffic for a protocol data unit (PDU) session based on the one or more ATSSS rules.

[0094] In some examples, the field set to indicate ATSSS-ST supported by the UE is set to indicate whether the UE supports either or both ATSSS-LL functionality with any steering mode, or multipath transmission control protocol (MPTCP) functionality.

[0095] In some examples, the bit is one of at least two bits outside of the field that are set to indicate whether the UE supports respective ones of ATSSS-LL-AS and multipath QUIC (MPQUIC) functionality.

[0096] In some examples, the bit is one of at least two bits outside of the field that are set to indicate whether the UE supports respective ones of ATSSS-LL-AS, and at least one of multipath QUIC (MPQUIC) user datagram protocol (MPQUIC-UDP) functionality, MPQUIC internet protocol (MPQUIC-IP) functionality, MPQUIC transport control protocol (MPQUIC-TCP) functionality, or MPQUIC ethernet (MPQUIC-E) functionality.

[0097] In some examples, bits of the field set to indicate ATSSS-ST supported by the UE are set to indicate ATSSS not supported, and one or more of the at least two bits outside of the field are set to indicate the UE supports one or more of ATSSS-LL-AS, MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E.

[0098] In some examples, the bit of the at least two bits is set to indicate the UE supports ATSSS-LL-AS when any other bit of the at least two bits is set to indicate the UE supports at least one of MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E.

[0099] In some examples, sending to the network the information indicating the ATSSS capabilities of the UE at block 804 comprises sending to the network a PDU session establishment request to initiate establishment of the PDU session, and In some of these examples, the PDU session establishment request includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

[0100] In some examples, the method 800 further includes sending to the network a PDU session establishment request to initiate establishment of the PDU session. In some of these examples, sending to the network the information indicating the ATSSS capabilities of the UE at block 804 comprises sending to the network a non-access stratum (NAS) message during the establishment of the PDU session, and the NAS message includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

[0101] In some examples, the method 800 further includes receiving from the network an indication of network support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS. In some of these examples, the NAS message is sent to the network based on the indication of the network support.

[0102] In some examples, the PDU session establishment request includes a version of the IE without the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and an indication of UE support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field. In some of these examples, the indication of the network support for the information indicating the ATSSS capabilities of the UE structured in the IE is received from the network based on the indication of the UE support.

[0103] In some examples, sending the information to the network indicating the ATSSS capabilities of the UE at block 804 comprises sending to the network a PDU session modification request to initiate modification of the PDU session, and the PDU session modification request includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

[0104] In some examples, the method 800 further includes receiving from the network an indication of network support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS. In some of these examples, the PDU session modification request is sent to the network based on the indication of the network support.

[0105] In some examples, the method 800 further includes sending to the network a PDU session establishment request to initiate establishment of the PDU session. In some of these examples, the PDU session establishment request includes a version of the IE without the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and an indication of UE support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS. Also in some of these examples, the indication ofthe network support for the information indicating the ATSSS capabilities of the UE structured in the IE is received from the network based on the indication of the UE support.

[0106] FIGS. 9A – 9C are flowcharts illustrating various steps in a method 900 according to various example implementations. The method includes receiving from a user equipment (UE) information indicating access traffic steering, switching and splitting (ATSSS) capabilities of the UE, as shown at block 902 of FIG. 9A. The information is structured in an information element (IE) including a field set to indicate ATSSS steering functionalities and steering modes (ATSSS-ST) supported by the UE, and including a bit outside of the field that is set to indicate whether the UE supports ATSSS low layer (ATSSS-LL) functionality with only active-standby steering mode (ATSSS-LL-AS). The method includes selecting an ATSSS steering functionality and steering mode based on ATSSS supported by the network and the ATSSS capabilities of the UE, as shown at block 904. And the method includes sending one or more ATSSS rules for the ATSSS steering functionality and steering mode to the UE for the UE to at least one of steer, split or switch traffic for a protocol data unit (PDU) session based on the one or more ATSSS rules, as shown at block 906.

[0107] In some examples, the method 900 further includes sending to a policy control function (PCF) information that indicates the ATSSS steering functionality and steering mode, as shown at block 908 of FIG. 9B. In some of these examples, the method also includes receiving from the PCF the one or more ATSSS rules for the ATSSS steering functionality and steering mode, as shown at block 910.

[0108] In some examples, the field set to indicate ATSSS-ST supported by the UE is set to indicate whether the UE supports either or both ATSSS-LL functionality with any steering mode, or multipath transmission control protocol (MPTCP) functionality.

[0109] In some examples, the bit is one of at least two bits outside of the field that are set to indicate whether the UE supports respective ones of ATSSS-LL-AS and multipath QUIC (MPQUIC) functionality.

[0110] In some examples, the bit is one of at least two bits outside of the field that are set to indicate whether the UE supports respective ones of ATSSS-LL-AS, and at least one of multipath QUIC (MPQUIC) user datagram protocol (MPQUIC-UDP) functionality, MPQUIC internet protocol (MPQUIC-IP) functionality, MPQUIC transport control protocol (MPQUIC-TCP) functionality, or MPQUIC ethernet (MPQUIC-E) functionality.

[0111] In some examples, bits of the field set to indicate ATSSS-ST supported by the UE are set to indicate ATSSS not supported, and one or more of the at least two bits outside of the field are set to indicate the UE supports one or more of ATSSS-LL-AS, MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E. In some of these examples, the ATSSS steering functionality and steering mode is selected at block 904 from the one or more of ATSSS-LL-AS, MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E indicated as supported by the UE.

[0112] In some examples, the bit of the at least two bits is set to indicate the UE supports ATSSS-LL-AS when any other bit of the at least two bits is set to indicate the UE supports at least one of MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E.

[0113] In some examples, selecting the ATSSS steering functionality and steering mode at block 904 comprises selecting ATSSS-LL-AS for the PDU session when at least one other bit of the at least two bits is set to indicate the UE supports at least one of MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E, but the network supports only ATSSS-LL-AS.

[0114] In some examples, receiving from the UE the information indicating the ATSSS capabilities of the UE at block 902 comprises receiving from the UE a PDU session establishment request to initiate establishment of the PDU session, and In some of these examples, the PDU session establishment request includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

[0115] In some examples, the method 900 further includes receiving from the UE a PDU session establishment request to initiate establishment of the PDU session, as shown at block 912 of FIG. 9C. In some of these examples, receiving from the UE the information indicating the ATSSS capabilities of the UE at block 902 comprises receiving from the UE a non-access stratum (NAS) message during the establishment of the PDU session, and the NAS message includes the IE in which the information indicating the ATSSS capabilities of the UE is structured, as shown at block 914.

[0116] In some examples, the method 900 further includes sending to the UE an indication of network support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS. In some of these examples, the NAS message is received at block 914 from the UE based on the indication of the network support.

[0117] In some examples, the PDU session establishment request includes a version of the IE without the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and an indication of UE support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field. In some of these examples, the indication of the network support for the information indicating the ATSSS capabilities of the UE structured in the IE is sent to the UE in a PDU session establishment accept, based on the indication of the UE support.

[0118] In some examples, receiving from the UE the information indicating the ATSSS capabilities of the UE at block 902 comprises receiving from the UE a PDU session modification request to initiate modification of the PDU session, and the PDU session modification request includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

[0119] In some examples, the method 900 further includes sending to the UE an indication of network support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS. In some of theseexamples, the PDU session modification request is received from the UE based on the indication of the network support.

[0120] In some examples, the method 900 further includes receiving from the UE a PDU session establishment request to initiate establishment of the PDU session. In some of these examples, the PDU session establishment request includes a version of the IE without the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and an indication of UE support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS. Also in some of these examples, the indication of the network support for the information indicating the ATSSS capabilities of the UE structured in the IE is sent to the UE in a PDU session establishment accept, based on the indication of the UE support.

[0121] According to example implementations of the present disclosure, a telecommunications system 100 or PLMN 102, and its components such as a UE 110, CN 106, RAN 108, RAN node 202, MM 204, SM 206, UPF 208 and / or PCF 210, may be implemented by various means. Means for implementing the system and its components may include hardware, firmware, software, or combinations thereof, in some examples, one or more apparatuses may be configured to function as or otherwise implement the system and its components shown and described herein. In examples involving more than one apparatus, the respective apparatuses may be connected to or otherwise in communication with one another in a number of different manners, such as directly or indirectly via a wired or wireless network or the like.

[0122] According to some example implementations, at least some of the method 800 described with respect to FIG. 8 may be carried out by an apparatus comprising means for performing functions corresponding steps of the method. Similarly, at least some of the method 900 described with respect to FIGS. 9A - 9C may be carried out by an apparatus comprising means for performing functions corresponding steps of the method. Examples of a suitable apparatus may include a user equipment, user device, user terminal or the like. Other examples of a suitable apparatus may include a MM NF, SM NF UPF, PCF or any suitable apparatus, such as a server, host or node.

[0123] FIG. 10 illustrates an apparatus 1000 in which means for performing various functions includes hardware, alone or under direction of one or more computer programs from a computer-readable storage medium or other memory, such as computer memory, according to some example implementations of the present disciosure. The apparatus may include one or more of each of a number of components such as, for example, processing circuitry 1002 connected to computer-readable storage medium or other memory 1004.

[0124] The processing circuitry 1002 may be composed of one or more processors aione or in combination with one or more computer-readable storage media. The processing circuitry is generally any piece of computer hardware that is capable of processing information such as, for example, data, computer programs and / or other suitable electronic information. The processing circuitry is composed of a collectionof electronic circuits some of which may be packaged as an integrated circuit or muitipie interconnected integrated circuits (an integrated circuit at times more commonly referred to as a “chip”). The processing circuitry may be configured to execute computer programs, which may be stored onboard the processing circuitry or otherwise stored in the memory 1004 (of the same or another apparatus).

[0125] The processing circuitry 1002 may be a number of processors, a multi-core processor or some other type of processor, depending on the particular implementation. Further, the processing circuitry may be implemented using a number of heterogeneous processor systems in which a main processor is present with one or more secondary processors on a single chip. As another illustrative example, the processing circuitry may be a symmetric multi-processor system containing multiple processors of the same type. In yet another example, the processing circuitry may be embodied as or otherwise include one or more ASICs, FPGAs or the like. Thus, although the processing circuitry may be capable of executing a computer program to perform one or more functions, the processing circuitry of various examples may be capable of performing one or more functions without the aid of a computer program, In either instance, the processing circuitry may be appropriately programmed to perform functions or operations according to example implementations of the present disclosure.

[0126] The memory 1004 is generally any piece of computer hardware that is capable of storing information such as, for example, data, computer programs, instructions 1006 (e.g., computer-readable program code) and / or other suitable information either on a temporary basis and / or a permanent basis. The memory may include volatile and / or non-volatile memory, and may be fixed or removable. Examples of suitable memory' include recording media, random access memory (RAM), read-only memory (ROM), a hard drive, a flash memory, a thumb drive, a removable computer diskette, an optical disk or some combination thereof.

[0127] The memory 1004 is a non-transitory device capable of storing information. One example of a suitable memory is a computer-readable storage medium, which is distinguishable from a computer- readable transmission medium capable of carrying information from one location to another. Examples of suitable computer-readable transmission media comprise electronic carrier signals, telecommunications signals, or some combination thereof. As used herein, the term “non-transitory'” is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM versus ROM). A computer-readable medium as described herein generally refers to a computer-readable storage medium or computer-readable transmission medium. A computer-readable medium is any entity or device capable in which information, such as one or more computer programs or portions thereof, may be stored and carried.

[0128] In addition to the memory 1004 (e.g., computer-readable storage medium), the processing circuitry 1002 may also be connected to one or more interfaces for displaying, transmitting and / or receiving information. The interfaces may include a communications interface 1008 and / or one or more userinterfaces. The communications interface may be configured to transmit and / or receive information, such as to and / or from other apparatuses), network(s) or the like. The communications interface may be configured to transmit and / or receive information by physical (wired) and / or wireless communications links. Examples of suitable communication interfaces include a network interface controller (NIC), wireless NIC (WNIC) or the like.

[0129] The user interfaces may include a display 1010 and / or one or more user input interfaces 1012. The display may be configured to present or otherwise display information to a user, suitable exampies of which include a liquid crystal display (LCD), light-emitting diode (LED) display, organic LED (OLED) display, active-matrix OLED (AMOLED) or the like. The user input interfaces may be wired or wireless, and may be configured to receive information from a user into the apparatus, such as for processing, storage and / or display. Suitable examples of user input interfaces include a microphone, image or video capture device, keyboard or keypad, joystick, touch-sensitive surface (separate from or integrated into a touchscreen), biometric sensor or the like. The user interfaces may further include one or more interfaces for communicating with peripherals such as printers, scanners or the like.

[0130] Execution of the instructions 1006 by the processing circuitry 1002, or storage of the instructions in the memory 1004, supports combinations of operations for implementing example implementations of the present disclosure. In this manner, an apparatus 1000 may comprise at least one processing circuitry and at least one memory coupled to the at least one processing circuitry, where the at least one processing circuitry is configured to execute instructions stored in the at least one memory. It will also be understood that one or more functions, and combinations of functions, may be implemented by special purpose hardware-based computer systems and / or processing circuitry which perform the specified functions, or combinations of special purpose hardware and program code instructions.

[0131] Some example implementations of the present disclosure may also be carried out in the form of a computer process defined by one or more computer programs or portions thereof. Example implementations of the present disclosure may be carried out by executing at least one portion of a computer program comprising instructions. The computer program may be in source code form, object code form, or in some intermediate form. The computer program may be stored in a computer-readable medium that is readable by a computer, processing circuitry or other suitable apparatus, As indicated above, for example, the computer program may be stored in a memory, such as a computer-readable storage medium. Additionally or alternatively, for example, the computer program may be stored in a computer-readable transmission medium. The coding of software for carrying out example implementations of the present disclosure is well within the scope of a person of ordinary skill in the art.

[0132] As will be appreciated, any suitable instructions may be loaded onto a computer, a processing circuitry or other programmable apparatus from a memory or a computer-readable medium (e.g., computer- readable storage medium, computer-readable transmission medium) to produce a particular machine, suchthat the particular machine becomes a means for implementing the functions specified herein. The instructions may also be stored in a computer-readable medium that can direct a computer, a processing circuitry or other programmable apparatus to function in a particular manner to thereby generate a particular machine or particular article of manufacture. In some examples, the instructions stored in the computer-readable medium may produce an article of manufacture, where the article of manufacture becomes a means for implementing functions described herein. The instructions may be retrieved from a computer-readable medium and loaded into a computer, processing circuitry or other programmable apparatus to configure the computer, processing circuitry or other programmable apparatus to execute operations to be performed on or by the computer, processing circuitry or other programmable apparatus,

[0133] Retrieval, loading and execution of instructions comprising program code instructions may be performed sequentially such that one instruction is retrieved, loaded and executed at a time. In some example implementations, retrieval, loading and / or execution may be performed in parallel such that multiple instructions are retrieved, loaded, and / or executed together. Execution of the program code instructions may produce a computer-implemented process such that the instructions executed by the computer, processing circuitry or other programmable apparatus provide operations for implementing functions described herein,

[0134] As explained above and reiterated below, the present disclosure includes, without limitation, the following example implementations.

[0135] Clause 1, A method performed by a user equipment (UE), the method comprising: determining that access traffic steering, switching and splitting (ATSSS) is supported by a network with which the UE is registered; sending to the network information indicating ATSSS capabilities of the UE, wherein the information is structured in an information element (IE) including a field set to indicate ATSSS steering functionalities and steering modes (ATSSS-ST) supported by the UE, and including a bit outside of the field that is set to indicate whether the UE supports ATSSS low layer (ATSSS-LL) functionality with only activestandby steering mode (ATSSS-LL-AS); receiving from the network one or more ATSSS rules determined by the network based on the ATSSS supported by the network and the ATSSS capabilities of the UE; and at least one of steering, splitting or switching traffic for a protocol data unit (PD U) session based on the one or more ATSSS rules.

[0136] Clause 2. The method of clause 1, wherein the field set to indicate ATSSS-ST supported by the UE is set to indicate whether the UE supports either or both ATSSS-LL functionality with any steering mode, or multipath transmission control protocol (MPTCP) functionality.

[0037] Clause 3. The method of clause 1 or ciause 2, wherein the bit is one of at least two bits outside of the field that are set to indicate whether the UE supports respective ones of ATSSS-LL-AS and multipath QUIC (MPQUIC) functionality.

[0138] Clause 4. The method of any of clauses 1 to 3, wherein the bit is one of at least two bits outside of the field that are set to indicate whether the UE supports respective ones of ATSSS-LL-AS, and at least one of multipath QUIC (MPQUIC) user datagram protocol (MPQUIC-UDP) functionality, MPQUIC internet protocol (MPQUIC-IP) functionality, MPQUIC transport control protocol (MPQUIC-TCP) functionality, or MPQUIC ethernet (MPQUIC-E) functionality.

[0139] Clause 5. The method of clause 4, wherein bits of the field set to indicate ATSSS-ST supported by the UE are set to indicate ATSSS not supported, and one or more of the at least two bits outside of the field are set to indicate the UE supports one or more of ATSSS-LL-AS, MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E.

[0140] Clause 6. The method of clause 4 or clause 5, wherein the bit of the at least two bits is set to indicate the UE supports ATSSS-LL-AS when any other bit of the at least two bits is set to indicate the UE supports at least one of MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E.

[0141] Clause 7. The method of any of clauses 1 to 6, wherein sending to the network the information indicating the ATSSS capabilities of the UE comprises sending to the network a PDU session establishment request to initiate establishment of the PDU session, and wherein the PDU session establishment request includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

[0142] Clause 8. The method of any of clauses 1 to 7, wherein the method further comprises sending to the network a PDU session establishment request to initiate establishment of the PDU session, and wherein sending to the network the information indicating the ATSSS capabilities of the UE comprises sending to the network a non-access stratum (NAS) message during the establishment of the PDU session, and the NAS message includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

[0143] Clause 9. The method of clause 8, wherein the method further comprises receiving from the network an indication of network support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and wherein the NAS message is sent to the network based on the indication of the network support.

[0144] Clause 10. The method of clause 9, wherein the PDU session establishment request includes a version of the IE without the bit outside of the field that is set to indicate whether the UE supports ATSSS- LL-AS, and an indication of UE support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field, and wherein the indication of the network support for the information indicating the ATSSS capabilities of the UE structured in the IE is received from the network based on the indication of the UE support.

[0145] Clause 11, The method of any of clauses 1 to 10, wherein sending the information to the network indicating the ATSSS capabilities of the UE comprises sending to the network a PDU session modification request to initiate modification of the PDU session, and the PDU session modification request includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

[0146] Clause 12. The method of clause 11, wherein the method further comprises receiving from the network an indication of network support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and wherein the PDU session modification request is sent to the network based on the indication of the network support.

[0147] Clause 13. The method of clause 12, wherein the method further comprises sending to the network a PDU session establishment request to initiate establishment of the PDU session, and the PDU session establishment request includes a version of the IE without the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and an indication of UE support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and wherein the indication of the network support for the information indicating the ATSSS capabilities of the UE structured in the IE is received from the network based on the indication of the UE support.

[0148] Clause 14. An apparatus comprising: at least one processor; and at least one memory storing instructions of a user equipment (UE), the instructions when executed by the at least one processor causing the apparatus to perform the method of any of clauses 1 to 13.

[0149] Clause 15. An apparatus comprising means for performing the method of any of clauses 1 to 13.

[0150] Clause 16. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 1 to 13.

[0151] Clause 17. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 1 to 13.

[0152] Clause 18. A computer program comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 1 to 13,

[0153] Clause 19. A method comprising: receiving from a user equipment (UE) information indicating access traffic steering, switching and splitting (ATSSS) capabilities of the UE, wherein the information is structured in an information element (IE) including a field set to indicate ATSSS steering functionalities and steering modes (ATSSS-ST) supported by the UE, and including a bit outside of the field that is set to indicate whether the UE supports ATSSS low layer (ATSSS-LL) functionality with only active-standby steering mode (ATSSS-LL-AS); selecting an ATSSS steering functionality and steering mode based on ATSSS supported by the network and the ATSSS capabilities of the UE; and sending one or more ATSSSrules for the ATSSS steering functionality and steering mode to the UE for the UE to at least one of steer, split or switch traffic for a protocol data unit (PDU) session based on the one or more ATSSS rules.

[0154] Clause 20. The method of clause 19 further comprising: sending to a policy control function (PCF) information that indicates the ATSSS steering functionality and steering mode; and receiving from the PCF the one or more ATSSS rules for the ATSSS steering functionality and steering mode.

[0155] Clause 21. The method of clause 19 or clause 20, wherein the field set to indicate ATSSS-ST supported by the UE is set to indicate whether the UE supports either or both ATSSS-LL functionality with any steering mode, or multipath transmission control protocol (MPTCP) functionality.

[0156] Clause 22. The method of any of clauses 19 to 21, wherein the bit is one of at least two bits outside of the field that are set to indicate whether the UE supports respective ones of ATSSS-LL-AS and multipath QUIC (MPQUIC) functionality.

[0157] Clause 23. The method of any of clauses 19 to 22, wherein the bit is one of at least two bits outside of the field that are set to indicate whether the UE supports respective ones of ATSSS-LL-AS, and at least one of multipath QUIC (MPQUIC) user datagram protocol (MPQUIC-UDP) functionality, MPQUIC internet protocol (MPQUIC-IP) functionality, MPQUIC transport control protocol (MPQUIC-TCP) functionality, or MPQUIC ethernet (MPQUIC-E) functionality.

[0158] Clause 24. The method of clause 23, wherein bits of the field set to indicate ATSSS-ST supported by the UE are set to indicate ATSSS not supported, and one or more of the at least two bits outside of the field are set to indicate the UE supports one or more of ATSSS-LL-AS, MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E, and wherein the ATSSS steering functionality and steering mode is selected from the one or more of ATSSS-LL-AS, MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E indicated as supported by the UE.

[0159] Clause 25. The method of clause 23 or clause 24, wherein the bit of the at least two bits is set to indicate the UE supports ATSSS-LL-AS when any other bit of the at least two bits is set to indicate the UE supports at least one of MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E.

[0160] Clause 26. The method of clause 25, wherein selecting the ATSSS steering functionality and steering mode comprises selecting ATSSS-LL-AS for the PDU session when at least one other bit of the at least two bits is set to indicate the UE supports at least one of MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E, but the network supports only ATSSS-LL-AS.

[0161] Clause 27. The method of any of clauses 19 to 26, wherein receiving from the UE the information indicating the ATSSS capabilities of the UE comprises receiving from the UE a PDU session establishment request to initiate establishment of the PDU session, and wherein the PDU session establishment request includes the IE in which the information indicating the ATSSS capabilities of the UE is structured,

[0162] Clause 28. The method of any of clauses 19 to 27, wherein the method further comprises receiving from the UE a PDU session establishment request to initiate establishment of the PDU session, andwherein receiving from the UE the information indicating the ATSSS capabilities of the UE comprises receiving from the UE a non-access stratum (NAS) message during the establishment of the PDU session, and the NAS message includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

[0163] Clause 29. The method of clause 28, wherein the method further comprises sending to the UE an indication of network support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and wherein the NAS message is received from the UE based on the indication of the network support.

[0164] Clause 30. The method of clause 29, wherein the PDU session establishment request includes a version of the IE without the bit outside of the field that is set to indicate whether the UE supports ATSSS- LL-AS, and an indication of UE support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field, and wherein the indication of the network support for the information indicating the ATSSS capabilities of the UE structured in the IE is sent to the UE in a PDU session establishment accept, based on the indication of the UE support.

[0165] Clause 31. The method of any of clauses 19 to 30, wherein receiving from the UE the information indicating the ATSSS capabilities of the UE comprises receiving from the UE a PDU session modification request to initiate modification of the PDU session, and the PDU session modification request includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

[0166] Clause 32. The method of clause 31, wherein the method further comprises sending to the UE an indication of network support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and wherein the PDU session modification request is received from the UE based on the indication of the network support.

[0167] Clause 33. The method of clause 32, wherein the method further comprises receiving from the UE a PDU session establishment request to initiate establishment of the PDU session, and the PDU session establishment request includes a version of the IE without the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and an indication of UE support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and wherein the indication of the network support for the information indicating the ATSSS capabilities of the UE structured in the IE is sent to the UE in a PDU session establishment accept, based on the indication of the UE support.

[0168] Clause 34. An apparatus comprising: at least one processor: and at least one memory storing instructions that when executed by the at least one processor causing the apparatus to perform the method of any of clauses 19 to 33.

[0169] Clause 35. An apparatus comprising means for performing the method of any of clauses 19 to 33.

[0170] Clause 36, A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 19 to 33.

[0171] Clause 37. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 19 to 33.

[0172] Clause 38. A computer program comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 19 to 33.

[0173] Many modifications and other implementations of the disclosure set forth herein will come to mind to one skilled in the art to which the disclosure pertains having the benefit of the teachings presented in the foregoing description and the associated figures. Therefore, it is to be understood that the disclosure is not to be limited to the specific implementations disclosed and that modifications and other implementations are intended to be included within the scope of the appended claims. Moreover, although the foregoing description and the associated figures describe example implementations in the context of certain example combinations of elements and / or functions, it should be appreciated that different combinations of elements and / or functions may be provided by alternative implementations without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and / or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

WE CLAIM:

1. A method performed by a user equipment (UE), the method comprising: determining that access traffic steering, switching and splitting (ATSSS) is supported by a network with which the UE is registered;sending to the network information indicating ATSSS capabilities of the UE, wherein the information is structured in an information element (IE) including a field set to indicate ATSSS steering functionalities and steering modes (ATSSS-ST) supported by the UE, and including a bit outside of the field that is set to indicate whether the UE supports ATSSS low layer (ATSSS-LL) functionality with only activestandby steering mode (ATSSS-LL-AS);receiving from the network one or more ATSSS rules determined by the network based on the ATSSS supported by the network and the ATSSS capabilities of the UE; andat least one of steering, splitting or switching traffic for a protocol data unit (PDU) session based on the one or more ATSSS rules.

2. The method of claim 1, wherein the field set to indicate ATSSS-ST supported by the UE is set to indicate whether the UE supports either or both ATSSS-LL functionality with any steering mode, or multipath transmission control protocol (MPTCP) functionality.

3. The method of claim 1 or claim 2, wherein the bit is one of at least two bits outside of the field that are set to indicate whether the UE supports respective ones of ATSSS-LL-AS and multipath QUIC (MPQUIC) functionality.

4. The method of any of claims 1 to 3, wherein the bit is one of at least two bits outside of the field that are set to indicate whether the UE supports respective ones of ATSSS-LL-AS, and at least one of multipath QUIC (MPQUIC) user datagram protocol (MPQUIC-UDP) functionality, MPQUIC internet protocol (MPQUIC-IP) functionality, MPQUIC transport control protocol (MPQUIC-TCP) functionality, or MPQUIC ethernet (MPQUIC-E) functionality.

5. The method of claim 4, wherein bits of the field set to indicate ATSSS-ST supported by the UE are set to indicate ATSSS not supported, and one or more of the at least two bits outside of the field are set to indicate the UE supports one or more of ATSSS-LL-AS, MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E.

6. The method of claim 4 or claim 5, wherein the bit of the at least two bits is set to indicate the UE supports ATSSS-LL-AS when any other bit of the at least two bits is set to indicate the UE supports at least one of MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E.

7. The method of any of claims 1 to 6, wherein sending to the network the information indicating the ATSSS capabilities of the UE comprises sending to the network a PDU session establishment request to initiate establishment of the PDU session, and wherein the PDU session establishment request includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

8. The method of any of claims 1 to 7, wherein the method further comprises sending to the network a PDU session establishment request to initiate establishment of the PDU session, and wherein sending to the network the information indicating the ATSSS capabilities of the UE comprises sending to the network a non-access stratum (NAS) message during the establishment of the PDU session, and the NAS message includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

9. The method of claim 8, wherein the method further comprises receiving from the network an indication of network support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, andwherein the NAS message is sent to the network based on the indication of the network support.

10. The method of claim 9, wherein the PDU session establishment request includes aversion of the IE without the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and an indication of UE support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field, andwherein the indication of the network support for the information indicating the ATSSS capabilities of the UE structured in the IE is received from the network based on the indication of the UE support.

11. The method of any of claims 1 to 10, wherein sending the information to the network indicating the ATSSS capabilities of the UE comprises sending to the network a PDU session modification request to initiate modification of the PDU session, and the PDU session modification request includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

12. The method of claim 11, wherein the method further comprises receiving from the network an indication of network support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, andwherein the PDU session modification request is sent to the network based on the indication of the network support.

13. The method of claim 12, wherein the method further comprises sending to the network a PDU session establishment request to initiate establishment of the PDU session, and the PDU session establishment request includes a version of the IE without the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and an indication of UE support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, andwherein the indication of the network support for the information indicating the ATSSS capabilities of the UE structured in the IE is received from the network based on the indication of the UE support.

14. An apparatus comprising:at least one processor; andat least one memory storing instructions of a user equipment (UE), the instructions when executed by the at least one processor causing the apparatus to perform the method of any of claims 1 to 14.

15. A method comprising:receiving from a user equipment (UE) information indicating access traffic steering, switching and splitting (ATSSS) capabilities of the UE, wherein the information is structured in an information element (IE) including a field set to indicate ATSSS steering functionalities and steering modes (ATSSS-ST) supported by the UE, and including a bit outside of the field that is set to indicate whether the UE supports ATSSS low layer (ATSSS-LL) functionality with only active-standby steering mode (ATSSS-LL-AS);selecting an ATSSS steering functionality and steering mode based on ATSSS supported by the network and the ATSSS capabilities of the UE; andsending one or more ATSSS rules for the ATSSS steering functionality and steering mode to the UE for the UE to at least one of steer, split or switch traffic for a protocol data unit (PDU) session based on the one or more ATSSS rules.

16. The method of claim 15 further comprising:sending to a policy control function (PCF) information that indicates the ATSSS steering functionality and steering mode; andreceiving from the PCF the one or more ATSSS rules for the ATSSS steering functionality and steering mode.

17. The method of claim 15 or claim 16, wherein the field set to indicate ATSSS-ST supported by the UE is set to indicate whether the UE supports either or both ATSSS-LL functionality with any steering mode, or multipath transmission control protocol (MPTCP) functionality.

18. The method of any of claims 15 to 17, wherein the bit is one of at least two bits outside of the field that are set to indicate whether the UE supports respective ones of ATSSS-LL-AS and multipath QUIC (MPQUIC) functionality.

19. The method of any of claims 15 to 18, wherein the bit is one of at least two bits outside of the field that are set to indicate whether the UE supports respective ones of ATSSS-LL-AS, and at least one of multipath QUIC (MPQUIC) user datagram protocol (MPQUIC-UDP) functionality, MPQUIC internet protocol (MPQUIC-IP) functionality, MPQUIC transport control protocol (MPQUIC-TCP) functionality, or MPQUIC ethernet (MPQUIC-E) functionality.

20. The method of claim 19, wherein bits of the field set to indicate ATSSS-ST supported by the UE are set to indicate ATSSS not supported, and one or more of the at least two bits outside of the field are set to indicate the UE supports one or more of ATSSS-LL-AS, MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E, andwherein the ATSSS steering functionality and steering mode is selected from the one or more of ATSSS-LL-AS, MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E indicated as supported by the UE.

21. The method of claim 19 or claim 20, wherein the bit of the at least two bits is set to indicate the UE supports ATSSS-LL-AS when any other bit of the at least two bits is set to indicate the UE supports at least one of MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E.

22. The method of claim 21, wherein selecting the ATSSS steering functionality and steering mode comprises selecting ATSSS-LL-AS for the PDU session when at least one other bit of the at least twobits is set to indicate the UE supports at least one of MPQUIC-UDP, MPQUIC-IP, MPQUIC-TCP or MPQUIC-E, but the network supports only ATSSS-LL-AS.

23. The method of any of claims 15 to 22, wherein receiving from the UE the information indicating the ATSSS capabilities of the UE comprises receiving from the UE a PDU session establishment request to initiate establishment of the PDU session, and wherein the PDU session establishment request includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

24. The method of any of claims 15 to 23, wherein the method further comprises receiving from the UE a PDU session establishment request to initiate establishment of the PDU session, and wherein receiving from the UE the information indicating the ATSSS capabilities of the UE comprises receiving from the UE a non-access stratum (NAS) message during the establishment of the PDU session, and the NAS message includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

25. The method of claim 24, wherein the method further comprises sending to the UE an indication of network support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, andwherein the NAS message is received from the UE based on the indication of the network support.

26. The method of claim 25, wherein the PDU session establishment request includes a version of the IE without the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and an indication of UE support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field, andwherein the indication of the network support for the information indicating the ATSSS capabilities of the UE structured in the IE is sent to the UE in a PDU session establishment accept, based on the indication of the UE support.

27. The method of any of claims 15 to 26, wherein receiving from the UE the information indicating the ATSSS capabilities of the UE comprises receiving from the UE a PDU session modification request to initiate modification of the PDU session, and the PDU session modification request includes the IE in which the information indicating the ATSSS capabilities of the UE is structured.

28. The method of claim 27, wherein the method further comprises sending to the UE an indication of network support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, andwherein the PDU session modification request is received from the UE based on the indication of the network support.

29. The method of claim 28, wherein the method further comprises receiving from the UE a PDU session establishment request to initiate establishment of the PDU session, and the PDU session establishment request includes a version of the IE without the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, and an indication of UE support for the information indicating the ATSSS capabilities of the UE structured in the IE including the bit outside of the field that is set to indicate whether the UE supports ATSSS-LL-AS, andwherein the indication of the network support for the information indicating the ATSSS capabilities of the UE structured in the IE is sent to the UE in a PDU session establishment accept, based on the indication of the UE support.

30. An apparatus comprising:at least one processor; andat least one memory storing instructions that when executed by the at least one processor causing the apparatus to perform the method of any of claims 15 to 29.

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