Handling of user-plane resources of pdu sessions of a dualsteer device

Abstract

DualSteer supports traffic steering and switching of user data across two access networks (RAN 108). A DualSteer device (400) may have two subscriptions (SUPI), and establish two PDU sessions, which m

Description

TECHNOLOGICAL FIELD

[0001] The present disclosure relates generally to telecommunications and, in particular, to steering, splitting and switching of traffic comprising user data across two radio 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 user equipment. 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 steering, splitting and switching of traffic comprising user data across two radio access networks in a telecommunications system. The present disclosure includes, without limitation, the following example implementations.

[0007] Some example implementations provide an apparatus to implement a session management function (SMF), the apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: request a user plane function (UPF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; determine which one of the two PDU sessions is the active PDU session; determine to deactivate user plane resources of the other of the two PDU sessions; and initiate, based on the determining to deactivate, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

[0008] Some example implementations provide an apparatus implemented by a session management function (SMF), the apparatus comprising: means for requesting an user plane function (UPF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; means for determining which one of the two PDU sessions is the active PDU session; means for determining to deactivate user plane resources of the other of the two PDU sessions; and means for initiating, based on the determining to deactivate, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

[0009] Some example implementations provide a method performed by a session management function (SMF), the method comprising: requesting a user plane function (UPF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; determining which one of the two PDU sessions is the active PDU session; determining to deactivate user plane resources of the other of the two PDU sessions; and initiating, based on the determining to deactivate, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

[0010] Some example implementations provide a computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes a session management function (SMF) to at least: request a user plane function (UPF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; determine which one of the two PDU sessions is the active PDU session; determine to deactivate user plane resources of the other of the two PDU sessions; and initiate, based on the determining to deactivate, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

[0011] Some example implementations provide an apparatus to implement a user plane function (UPF), the apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: receive requests from a session management function (SMF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; determine which one of the two PDU sessions is the active PDU session; and route downlink traffic through the one of the two PDU sessions as the active PDU session.

[0012] Some example implementations provide an apparatus to implement an user plane function (UPF), the apparatus comprising: means for receiving requests from a session management function (SMF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; means for determining which one of the two PDU sessions is the active PDU session; and means for routing downlink traffic through the one of the two PDU sessions as the active PDU session.

[0013] Some example implementations provide a method performed by a user plane function (UPF), the method comprising: receiving requests from a session management function (SMF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; determining which one of the two PDU sessions is the active PDU session; and routing downlink traffic through the one of the two PDU sessions as the active PDU session.

[0014] Some example implementations provide a computer-readable storage medium that is non-transitory and having instructions stored therein that, in response to execution by at least one processing circuitry, causes a user plane function (UPF) to at least: receive requests from a session management function (SMF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; determine which one of the two PDU sessions is the active PDU session; and route downlink traffic through the one of the two PDU sessions as the active PDU session.

[0015] Some example implementations provide an apparatus implemented by a dual steer device, the apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: send packet data unit (PDU) session establishment requests to request a session management function (SMF) to establish two packet data unit (PDU) sessions, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session that is indicated in at least one of the PDU session establishment requests, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; send uplink traffic through the one of the two PDU sessions as the active PDU session, wherein user plane resources for the other of the two PDU sessions are deactivated; determine to switch to the other of the two PDU sessions to be the active PDU session; and initiate, based on the determining to switch, one or more operations of a procedure to activate the user plane resources of the other of the two PDU sessions.

[0016] Some example implementations provide an apparatus implemented by a dual steer device, the apparatus comprising: means for sending packet data unit (PDU) session establishment requests to request a session management function (SMF) to establish two packet data unit (PDU) sessions, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session that is indicated in at least one of the PDU session establishment requests, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; means for sending uplink traffic through the one of the two PDU sessions as the active PDU session, wherein user plane resources for the other of the two PDU sessions are deactivated; means for determining to switch to the other of the two PDU sessions to be the active PDU session; and means for initiating, based on the determining to switch, one or more operations of a procedure to activate the user plane resources of the other of the two PDU sessions.

[0017] Some example implementations provide a method performed by a dual steer device, the method comprising: sending packet data unit (PDU) session establishment requests to request a session management function (SMF) to establish two packet data unit (PDU) sessions, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session that is indicated in at least one of the PDU session establishment requests, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; sending uplink traffic through the one of the two PDU sessions as the active PDU session, wherein user plane resources for the other of the two PDU sessions are deactivated; determining to switch to the other of the two PDU sessions to be the active PDU session; and initiating, based on the determining to switch, one or more operations of a procedure to activate the user plane resources of the other of the two PDU sessions.

[0018] Some example implementations provide a computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes a dual steer device to at least: send packet data unit (PDU) session establishment requests to request a session management function (SMF) to establish two packet data unit (PDU) sessions, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session that is indicated in at least one of the PDU session establishment requests, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; send uplink traffic through the one of the two PDU sessions as the active PDU session, wherein user plane resources for the other of the two PDU sessions are deactivated; determine to switch to the other of the two PDU sessions to be the active PDU session; and initiate, based on the determining to switch, one or more operations of a procedure to activate the user plane resources of the other of the two PDU sessions.

[0019] 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.

[0020] 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)

[0021] 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:

[0022] 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;

[0023] FIG. 2 illustrates a deployment of a PLMN, according to some example implementations;

[0024] FIG. 3 more particularly depicts aspects of a 5G deployment, referred to at times as the 5G system (5GS), according to some example implementations;

[0025] FIG. 4 illustrates a DualSteer device in the 5GS, according to some example implementations;

[0026] FIGS. 5A, 5B and 5C illustrate a signaling chart of DualSteer procedures, according to some example implementations;

[0027] FIGS. 6 A, 6B and 6C illustrate a signaling chart of Dual Steer procedures, according to other example implementations;

[0028] FIGS. 7A and 7B are flowcharts illustrating various steps in a method performed by a session management function (SMF), according to various example implementations;

[0029] FIGS. 8A and 8B are flowchart illustrating various steps in a method performed by a user plane function (UPF), according to various example implementations;

[0030] FIG. 9 is a flowchart illustrating various steps in a method performed by a dual steer device, according to various example implementations;

[0031] FIG. 10 illustrates an apparatus according to some example implementations. DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[0034] 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.

[0035] Reference may be made herein to terms specific to a particular system, architecture or the like, but it should be understood that example implementations of the present disclosure may be equally applicable to any of a number of systems, architectures and the like. For example, reference may be made to 3GPP technologies such as Global System for Mobile Communications (GSM), UMTS, LTE, LTE Advanced, 5GNR, 5G Advanced and 6G; however, it should be understood that example implementations of the present disclosure may be equally applicable to non-3GPP technologies such as IEEE 802, Bluetooth and Bluetooth Low Energy.

[0036] 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 work together 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.

[0037] 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.

[0038] 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 more public land mobile networks (PLMNs) 102 coupled to one or more other external data networks 104 - notably including a wide area network (WAN) such as the Internet. Each of the PLMNs includes a core network (CN) 106 backbone such as the Evolved Packet Core (EPC) of LTE, the 5G core network (5GC) or the like; and each of the core networks and the Internet are coupled to one or more radio access networks (RANs) 108, air interfaces or the like that implement one or more radio access technologies (RATs). 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.

[0039] In addition, the system 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 (IIoT 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-IoT) device, an enhanced machine-type communication (eMTC) device, a reduced capability (RedCap) device, an ambient loT device, or the like.

[0040] In operation, these UEs 110 may be configured to connect to one or more of the RANs 108 according to their particular radio access technologies 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 be configured to 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).

[0041] Examples of radio access technologies include 3GPP radio access technologies such as GSM, UMTS, LTE, LTE Advanced, 5GNR, 5G Advanced, and 6G. Other examples of radio access technologies 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 radio access technology may refer to any 2G, 3G, 4G, 5G, 6G or higher generation mobile communication technology and their different versions, as well as to any other wireless radio access technology that may be arranged to interwork with such a mobile communication technology to provide access to the CN 106 of a mobile network operator (MNO).

[0042] 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 radio access nodes that are configured to interact with UEs 110. In various examples, a radio access 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), or the like. The RAN may include some type of network controlling / governing entity responsible for control of the radio access nodes. The network controlling / governing entity and radio access 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.

[0043] ARAN 108 may be centralized or distributed. In various examples, components of a RAN may be interconnected by Ethernet, Gigabit Ethernet, Asynchronous Transfer Mode (ATM), optical fiber, dark fiber, passive wavelength division multiplexing (WDM), WDM passive optical network (WDM-PON), optical transport network (OTN), time sensitive networking (TSN) and / or any other data link layer network, possibly including radio links. The RAN may be connected to a CN 106 through one or more gateways, network functions or the like.

[0044] As will be appreciated, a PLMN 102 may be deployed in a number of different manners. FIG. 2 illustrates a deployment 200 of a PLMN, such as a 4G LTE, 5G or 6G deployment, according to some example implementations. As shown, the deployment includes a CN 106, and RAN 108 with one or more radio access nodes 202 configured to interact with UEs 110. In a 4G LTE deployment, the EPC is the CN, and the evolved UMTS terrestrial radio access network (E-UTRAN) is the RAN; and the E-UTRAN includes one or more eNBs (radio access nodes) configured to connect UEs to the E-UTRAN to thereby access the EPC. Similarly, in a 5G deployment, the 5GC is the CN 106, and the next generation (NG) radio access network (NG-RAN) is the RAN 108; and the NG-RAN includes one or more gNBs (radio access nodes) configured to connect UEs 110 to the NG-RAN to thereby access the 5GC (at times referred to as the NGC). The term ‘gNB’ in 5G may correspond to the eNB in 4G LTE.

[0045] Some deployments of 4G LTE and 5G in particular are considered standalone (SA) deployments. Other deployments combine 4G LTE and 5G technologies, and are referred to as non-standalone (NSA) deployments. In some deployments, the E-UTRAN includes one or more ng-eNBs that are configured to communicate with the 5GC, and that may also be configured to communicate with one or more gNBs. Similarly, in another deployment, the NG-RAN may include one or more en-gNBs that are configured to communicate with the EPC, and that may also be configured to communicate with one or more eNBs. In various instances, a single UE 110, a dual-mode or multimode UE, may support multiple (two or more) RANs—thereby being configured to connect to multiple RANs, such as 4G LTE and 5G.

[0046] FIG. 3 more particularly depicts aspects of a 5G deployment for a MNO, referred to at times as the 5G system (5GS) 300, according to some example implementations. As shown, the 5G deployment includes a 5GC 302, and NG-RAN 304 with one or more gNBs 306 configured to connect UEs 110 to the NG-RAN to thereby access the 5GC. The 5GC may include a number of network functions (NFs) divided between the control plane (CP) and the user plane (UP). In particular, the 5GC may include, for example, an access and mobility management function (AMF) 308, a session management function (SMF) 310, a user plane function (UPF) 312, and the like. Another example of a NF is a policy control function (PCF).

[0047] In the control plane, the AMF 308 is configured to provide UE-based authentication, authorization, mobility management, etc. The SMF 310 is configured to provide various functionality including session management (SM), UE Internet Protocol (IP) address allocation and management, selection and control of UPF(s) 312, control part of policy enforcement and quality of service (QoS), lawful intercept, termination of SM parts of NAS messages, downlink data notification (DDN), roaming functionality, handle local enforcement to apply QoS for service level agreements (SLAs), charging data collection and charging interface, etc. If the UE 110 has multiple sessions, different SMFs may be allocated to each session to manage them individually and possibly provide different functionalities per session.

[0048] The UPF 312 supports various user plane operations and functionalities, such as packet routing and forwarding, traffic handling (e.g., QoS enforcement), an anchor point for intra-RAT / inter-RAT mobility (when applicable), packet inspection and policy rule enforcement, lawful intercept (UP collection), traffic accounting and reporting, etc. The UPF is the point of interconnect between the 5GC and external data networks (i.e., point of ingress or egress for a data network), and routes packets to and from the data network. As explained above, data network may be configured to provide Internet access, operator services, 3rd party services, etc.

[0049] As also shown in FIG. 3, in some deployments, operations of the gNB 306 or other radio access node may be carried out, at least partly, in a central / centralized unit (CU) 314 (referred to at times as a gNB-CU), such as a server, host or node, operationally coupled to a distributed unit (DU) 316 (referred to at times as a gNB-DU), such as a radio head / node. It is also possible that node operations may be distributed among a plurality of servers, hosts or nodes.

[0050] It should also be understood that the distribution of work between 5GC 302 operations and gNB 306 operations may vary depending on implementation. Thus, a 5G network architecture may be based on a so-called CU-DU split. One CU 314 / gNB-CU (central node) may control one or more DUs 316 / gNB-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 (also called DU) may include, for example, a radio link control (RLC), medium access control (MAC) layer and a physical (PHY) layer, whereas the gNB-CU (also called a 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 a skilled person is familiar with the open systems interconnection (OSI) model and the functionalities within each layer.

[0051] In some example implementations, the server or CU 314 may generate a virtual network through which the server communicates with the radio node. In general, virtual networking may involve a process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Such virtual network may provide flexible distribution of operations between the server and the radio head / node. In practice, any digital signal processing task may be performed in either the CU or the DU 316, and the boundary where the responsibility is shifted between the CU and the DU may be selected according to implementation.

[0052] In 3GPP, gap analysis and studies have been conducted on potential service requirements related to 5GS support of enhanced mechanisms for steering, splitting and switching of traffic comprising user data, pertaining to a UE data session, across two RANs 108. In this regard, a DualSteer device (at times referred to as a dual steer device) is a device supporting traffic steering and switching of traffic comprising user data (for different services) across two RANs (e.g., 3GPP access networks). A DualSteer device may comprise a single UE 110, in case of non-simultaneous data transmission over the two RANs, or two separate UEs in case of simultaneous data transmission over the two radio networks.

[0053] As currently specified in 3GPP, DualSteer includes supporting mechanisms to enable traffic steering and switching of a DualSteer device’s user data across two 3GPP access networks (RANs 108), assuming data anchoring in the home PLMN (HPLMN). These mechanisms should also minimize service interruption when switching between the networks. Additionally, these mechanisms should support changing from one 3GPP access network to a non-3GPP access network of the same subscription and vice versa.

[0054] The target scenarios for these mechanisms include traffic steering and switching between two 3GPP access networks, whether the access networks belong to the same or different PLMNs 102, and whether the access network utilize the same or different RATs. This also includes traffic steering and switching between a 3GPP access network and a public network integrated - non-public network (PNI-NPN), as well as across LTEZEPC and NR / 5GC, with anchoring in 5GC 300.

[0055] It is assumed that the HPLMN is in full control of traffic policies, providing the necessary policies and criteria for a Dual Steer device to connect to an additional PLMN / NPN or an additional RAT within the same PLMN. Furthermore, a subscriber may have two subscriptions / SUPIs (subscription permanent identifiers) sharing one subscription profile from the same MNO.

[0056] FIG. 4 illustrates a DualSteer device 400 in the 5GS 300, according to some example implementations. The DualSteer device has two subscriptions / SUPIs (SUPI-1 402A, SUPL2 402B) that are linked to a single subscription profile from the same MNO. The DualSteeer device may include a DualSteer layer 402 to perform steering and switching of application traffic for an application Appl 404 between the two SUPIs. The DualSteer layer may be provided with rules (DualSteer rules 406) for steering and / or switching of traffic across two RANs (RAN-1 108A, RAN-2 108B), and the HPLMN may be assumed to have full control over the rules and policies provided to the Dual Steer device and to the network (in UPF 312). As also shown, the DualSteer device may access RAN-1 and RAN-2 using the two different SUPIs, which from the network point of view, may be associated with two different UEs (UE-1, UE-2) that perform independent registration and packet data unit (PDU) session establishment procedures.

[0057] A DualSteer device 400 registers to two different RANs 108A, 108B using two SUPIs. For any detected application traffic, the DualSteer device establishes two PDU session (one associated with each respective SUPI). The network links the two PDU sessions such that the two PDU sessions are served by a single SMF 310, UPF 312, PCF, etc.

[0058] The Dual Steer device 400 sends application traffic only via use of one SUPI or UE (accordingly to the Dual Steer rules 406 provided by network), and the Dual Steer device may switch the application traffic to use the other SUPI or UE when one or more switching conditions are met. Also based on the Dual Steer rules, the application traffic may be sent / received only through the RAN associated with one SUPI or UE, namely, the PDU Session is active via use of or in only one SUPI or UE. Even further, when the DualSteer device decides to switch the traffic from the PDU sessions that are subject to switching, ta UP connection associated with second SUPI or UE is activated for the corresponding PDU Session(s) using a UE-triggered service request procedure, and the Dual Steer device moves the application traffic from being associated the first SUPI or UE to the second SUPI or UE. In these situations, however, there are a number of problems with respect to how the second, standby PDU session is indicated, how usage of the standby PDU session is controlled, and handling of the UP resources of the standby PDU session.

[0059] In view of the foregoing, example implementations of the present disclosure provide solutions to the above problems. According to some example implementations, the SMF 312 in the 5GC 302 may deactivates the UP resources of the standby PDU session that is not used for transmitting the application traffic for DualSteer in the DualSteer device 400. This deactivation may save resources and energy at the DualSteer device and network elements / gNB 306 due to the release of the UP resources that are no longer used. It may also prevent unintentional use of the standby PDU session until its UP resources are later re-established.

[0060] In some example implementations, the Dual Steer layer 404 may indicate to each UE or UE associated with a respective SUPI (herein UE / SUPI) 402A, 402B whether the UE / SUPI utilizes a SUPI that is associated with an active PDU session (herein, an active SUPI) or utilizes a SUPI that is associated with a standby PDU session (herein, a standby SUPI). In these example implementations, the SMF 310 may trigger deactivation of the UP resources for the standby PDU session after the SMF receives information from the UE / SUPI during PDU session establishment that indicates whether the PDU session is the active PDU session or the standby PDU session (as per the Dual Steer rules 406 in the UE - provided by the Dual Steer layer). The SMF may then deactivate the UP resources for the standby PDU session immediately after the active PDU session has been established.

[0061] Also, in some of these example implementations, the SMF 310 may deliver the active / standby PDU session information to the UPF 312 to allow the UPF to know which PDU session is the active PDU session that the UPF can use for pushing downlink (DL) traffic.

[0062] The solution of these example implementations has an impact on the UE / SUPI in that the UE / SUPI may set an active or standby flag, or otherwise indicate the PDU session as active or standby, in a PDU session establishment request based on the DualSteer rules 406 at the UE / SUPI. The solution may resolve a problem related to what happens if there is DL traffic first on the PDU session(s) of the Dual Steer device 400 before any uplink (UL) traffic. The UPF 312 may be notified by the indication from the UE (through the SMF 310) of which of the PDU sessions is the active PDU session in order to trigger the traffic on the active PDU session.

[0063] In some examples of the solution, any change in the active / standby status of the PDU session may be communicated by the UE / SUPI to the network (SMF 310 and on to the UPF 312) through a UE-triggered PDU session modification procedure.

[0064] In some other example implementations, the SMF 310 may trigger deactivation of the UP resources for the standby PDU session once the UP resources of the other (active) PDU session that is used for switching the traffic has been successfully activated. In these other example implementations, during PDU session establishment, the SMF may request an event notification from the UPF 312 when any traffic is detected on one of the two PDU sessions. After the two PDU sessions are established, based on the DualSteer rules 406, the Dual Steer device 400 sends UL traffic via one of the two PDU sessions. The UPF detects the application traffic, and memorizes the active path (active PDU session) to be used for DL traffic. The UPF also sends an event notification to the SMF, which then deactivates the UP resources of the other (standby) PDU session.

[0065] Also, in some of these other example implementations, the SMF 310 may provide an indication to the UPF 312 that may be used to inform the PCF not to request activating the deactivated UP resources, and to use only the available UP resources (of the active PDU session that is used for steering or switching the traffic) when there is DL traffic targeting the DualSteer PDU sessions. This indication may also help, when the two UP resources of the two PDU sessions are not active due to no activity and then there is an incoming DL traffic, to determine which one of the PDU sessions to activate. In one example implementation, in this situation, one of the two PDU sessions may be activated. For instance, the last active PDU session may, according to the Dual Steer rules 406, may be activated.

[0066] To illustrate some example implementations, FIGS. 5A-5C illustrate a signaling chart 500 of Dual Steer procedures, according to some examples. In some of these examples, each of UE-l / SUPI-1 402A and UE-2 / SUPI-2 402B, during a respective PDU session establishment procedure, indicates whether the PDU session is the active PDU session or the standby PDU session, which may be based on information obtained from the DualSteer layer 402. The SMF 310 may then deactivate the UP resources (UP connection) of the standby PDU session (e.g., immediately) after the UP resources of the active PDU session have been established. The SMF may also deliver this information (indicative of which is active / standby PDU session) to the UPF 312 to allow the UPF to know which is the active PDU session for pushing DL traffic.

[0067] As shown in FIG. 5A, UE-l / SUPI-1 402A at step 501 successfully registers to the network (in AMF 308) through RAN-1 108A and receives DualSteer rules that indicate to use UE-2 / SUPI-2 402B for steering. UE-2 / SUPI-2 at step 602 successfully registers to the network through RAN-1 108B and receives the DualSteer rules. Traffic for application Appl 404 requiring Dual Steering is triggered at step 503. And UE-l / SUPI-1 402A and UE-2 / SUPI-2 402B initiate respective UE requested PDU session establishment procedures for respective ones of PDU session 1 and PDU session 2.

[0068] During the UE requested PDU session establishment procedure for PDU session 1, UE-l / SUPI-1 at step 504 sends a PDU session establishment request to the SMF 310 (by way of the AMF 310) in which UE-l / SUPI-1 provides a PDU session identity (ID) for PDU session 1. The SMF at step 505 initiates a corresponding N4 session establishment procedure with the UPF 312 by sending a session establishment request (e.g., N4 session establishment request) for PDU session 1. The PDU session establishment request from UE-l / SUPI-1 indicates that dual steering is required (e.g., “DualSteer required”) and that PDU session 1 is the standby PDU session; and the SMF passes this information to the UPF in the session establishment request.

[0069] During establishment of PDU session 1, UP resources may be established for a UP connection for PDU session 1. These UP resources may include a data radio bearer between UE-l / SUPI-1 402A and RAN-1 108A, and a tunnel (e.g., N3 tunnel) between RAN-1 108A and the UPF 312, to carry traffic for PDU session 1 between UE-l / SUPI-1 and the UPF. The tunnel may be conceptually divided into an access network (AN) tunnel (AN tunnel information) on the RAN-1 side, and a CN tunnel (CN tunnel information) on the 5GC side.

[0070] Similar to UE-l / SUPI-1 402A, UE-2 / SUPI-2 at step 506 sends a PDU session establishment request to the SMF 310 (by way of the AMF 310) in which UE-2 / SUPI-2 provides a PDU session ID for PDU session 2, indicates that dual steer is required (e.g., “DualSteer required”) and that PDU session 2 is the active PDU session. In some examples, the PDU session establishment request may also include the PDU session ID for PDU session 1 as a linked PDU session for Dual Steer. The SMF at step 507 initiates a corresponding session establishment procedure (e.g., N4 session establishment procedure) with the UPF 312 by sending a session establishment request (e.g., N4 session establishment request) for PDU session 1. The N4 session establishment request also indicates dual steer is required (e.g., “DualSteer required”), and that PDU session 2 is the active PDU session.

[0071] During establishment of PDU session 2, UP resources may be established for a UP connection for PDU session 2. As above, these UP resources may include a data radio bearer between UE-2 / SUPI-2 402B and RAN-2 108B, and a tunnel (e.g., N3 tunnel) between RAN-2 108B and the UPF 312, to carry traffic for PDU session 2 between UE-2 / SUPI-2 and the UPF.

[0072] As shown in FIG. 5B, the UPF 312 at steps 508, 509 becomes aware that PDU session 2 is the active PDU session (active access path) and sends any DL traffic for the application Appl 404 through PDU session 2. The SMF 310 at step 510 decides to deactivate the UP resources (data radio bearer, tunnel (e.g., N3 tunnel)) for PDU session 1. That is, the SMF determines that the UP connection of PDU session 1 can be deactivated, as PDU session 1 is the standby PDU session. The SMF then at step 511 triggers a procedure for CN-initiated selective deactivation of the UP connection of PDU session 1, such as according to 3GPP TS 23.502.

[0073] Sometime later, as shown at step 512, a condition for traffic switching is met due to, for example, mobility of the Dual Steer device 400. The DualSteer device at step 513 decides to switch the traffic from UE-2 / SUPI-2 402B (PDU session 2) to UE-l / SUPI-1 402A (PDU session 1). UE-l / SUPI-1 at step 514 triggers a service request procedure to activate UP resources (data radio bearer, N3 tunnel) for PDU session 1. That is, the UE-l / SUPI-1 may trigger the service request procedure to request activation of a UP connection for PDU session 1. As shown at step 515, UP resources of PDU session 1 are successfully established between UE-l / SUPI-1 and RAN-1 108A. RAN-1 at step 516 sends SM information ((e.g., N2 SM information (e.g., AN tunnel information)) for PDU session 1 to the SMF 310 (via the AMF 308). The SMF at step 517 initiates a session modificaiton procedure (e.g., N4 session modification procedure) with the UPF 312 by sending a N4 session modification request for PDU session 1. The session modification request indicates dual steer required (e.g., “DualSteer required”) and that PDU session 1 is (now) the active PDU.

[0074] As shown in FIG. 5C, the UPF 312 at steps 518, 519 becomes aware that PDU session 1 is the active PDU session (active access path) and sends any DL traffic for the application Appl 404 through PDU session 1. The SMF 310 at step 520 decides to deactivate the UP resources (data radio bearer, tunnel (e.g., N3 tunnel)) for PDU session 2. That is, the SMF determines that the UP connection of PDU session 2 can be deactivated, as PDU session 2 is (now) the standby PDU session. The SMF then at step 521 triggers a procedure for CN-initiated selective deactivation of the UP connection of PDU session 2, such as in the same manner earlier described for PDU session 1.

[0075] Sometime later, as shown at step 522, traffic for the application Appl 406 is finished, and the UP resources of PDU session 1 are release due to inactivity. That is, the UP connection of PDU session 1 is released due to inactivity. Now, neither PDU session 1 nor PDU session 2 has UP resources (or UP connection).

[0076] The UPF 312 at step 523 detects incoming DL traffic for the DualSteer device 400. The UPF at step 524 triggers a service request procedure to activate UP resources (data radio bearer, tunnel (e.g., N3 tunnel)) for PDU session 1 as the last active PDU session (active path). In this regard, the UPF may trigger the service request procedure to request activation of a UP connection for PDU session 1, which may be carried out as described in 3GPP TS 23.502.

[0077] FIGS. 6A-6C illustrate a signaling chart 600 of Dual Steer procedures, according to other example implementations. As shown in FIG. 6A, the DualSteer procedures include steps 501-503, as descried above. That is; UE-l / SUPI-1 402A and UE-2 / SUPL2 402B successfully register to the network (in AMF 308) through respectively RAN-1 108A and RAN-2 108B, and both receive DualSteer rules that indicate to use UE-2 / SUPL2 for steering. Traffic for application Appl 404 requiring DualSteering is triggered; and again, UE-l / SUPI-1 and UE-2 / SUPI-2 initiate respective UE requested PDU session establishment procedures for respective ones of PDU session 1 and PDU session 2.

[0078] During the UE requested PDU session establishment procedure for PDU session 1, UE-l / SUPI-1 402A at step 604 sends a PDU session establishment request to the SMF 310 (by way of the AMF 310) in which UE-l / SUPI-1 provides a PDU session identity (ID) for PDU session 1. The SMF at step 605 initiates a corresponding N4 session establishment procedure with the UPF 312 by sending a session establishment request (e.g., N4 session establishment request) for PDU session 1. The PDU session establishment request from UE-l / SUPI-1 indicates dual steer required (e.g., “DualSteer required”) and the SMF passes this information to the UPF in the session establishmemt request (e.g., N4 session establishment request). The indication may inform the UPF to use only the active UP resources (of the active PDU session) for any DL traffic to the Dual Steer device 400 (indicating to the UPF not to request activating the other UP resources of the other PDU session). As before, UP resources may be established for a UP connection for PDU session 1 during establishment of PDU session 1.

[0079] Similar to UE-l / SUPI-1 402A, UE-2 / SUPI-2 at step 606 sends a PDU session establishment request to the SMF 310 (by way of the AMF 310) in which UE-2 / SUPI-2 provides a PDU session identity (ID) for PDU session 2, and indicates dual steer required (e.g., “DualSteer required”). The PDU session establishment request may also include the PDU session ID for PDU session 1 (linked PDU session for Dual Steer). The SMF at step 607 initiates a corresponding session establishment procedure (e.g., N4 session establishment procedure) with the UPF 312 by sending a session establishment request (e.g., N4 session establishment request) for PDU session 1. The session establishment request also indicates dual steer required (e.g., “DualSteer required”) (indicating to the UPF to use only the active UP resources for any DL traffic to the DualSteer device 400). And again, UP resources may be established for a UP connection for PDU session 2 during establishment of PDU session 2.

[0080] As shown at step 608, traffic (e.g., UL traffic) for the application Appl 406 is transmitted through PDU session 2. As traffic is received through PDU session 2, the UPF 312 at step 609 memorizes PDU session 2 as the active PDU session (active access path) and sends any DL traffic to the Dual Steer device 400 through PDU session 2, as shown in FIG. 6B. The UPF at step 610 reports detected traffic on UE-2 / SUPI-2 402B (for PDF session 2) to the SMF 310.

[0081] The SMF 310 at step 611 decides to deactivate the UP resources (data radio bearer, tunnel (e.g., N3 tunnel)) for PDU session 1. That is, the SMF determines that the UP connection of PDU session 1 can be deactivated, as PDU session 1 is the standby PDU session. The SMF then at step 612 triggers a procedure for CN-initiated selective deactivation of the UP connection of PDU session 1, such as according to 3GPP TS 23.502.

[0082] Sometime later, as shown at step 613, a condition for traffic switching is met due to, e.g., mobility of the Dual Steer device 400. The Dual Steer device at step 614 decides to switch the traffic from UE-2 / SUPI-2 402B (PDU session 2) to UE-l / SUPI-1 402A (PDU session 1). UE-l / SUPI-1 at step 615 triggers a service request procedure to activate UP resources (data radio bearer, N3 tunnel) for PDU session 1. That is; the UE-l / SUPI-1 may trigger the service request procedure to request activation of a UP connection for PDU session 1. UP resources of PDU session 1 are successfully established between UE-l / SUPI-1 and RAN-1 108A at step 616, and RAN-1 at step 617 sends N2 SM information (e.g., AN tunnel information) for PDU session 1 to the SMF 310 (via the AMF 308).

[0083] As shown in FIG. 6C, the SMF 310 at step 618 decides to deactivate the UP resources (data radio bearer, tunnel (e.g., N3 tunnel)) for PDU session 2. That is, the SMF determines that the UP connection of PDU session 2 can be deactivated, as PDU session 2 is (now) the standby PDU session. In some examples, this decision / determination may be made based on one or more of the following information: AN tunnel information for PDU session 1, prior information that the two PDU sessions are used for DualSteer (e.g., “DualSteer required” indication), and / or having a linked PDU session ID included during establishment of PDU session 2.

[0084] The SMF 310 at step 619 triggers a procedure for CN-initiated selective deactivation of the UP connection of PDU session 2, such as in the same manner earlier described for PDU session 1. Traffic for the application Appl 406 is switched to be transmitted through PDU session 1 at step 620. As traffic is now received through PDU session 1, the UPF 312 at step 621 memorizes PDU session 1 as the active PDU session (active access path) and sends any DL traffic to the DualSteer device 400 through PDU session 1. Sometime later, traffic for the application Appl 406 is finished, and the procedures may continue with steps 522-524 as described above.

[0085] FIGS. 7A and 7B are flowcharts illustrating various steps in a method 700 performed by a session management function (SMF), according to various example implementations. The method includes requesting a user plane function (UPF) to establish two packet data unit (PDU) sessions for a dual steer device, as shown at block 702 of FIG. 7A. The two PDU sessions comprise a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device. Traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session. The method includes determining which one of the two PDU sessions is the active PDU session, as shown at block 704. The method includes determining to deactivate user plane resources of the other of the two PDU sessions, as shown at block 706. And the method includes initiating, based on the determining to deactivate, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions, as shown at block 708.

[0086] In some examples, the requesting to establish the two PDU sessions comprises receiving, from the dual steer device, PDU session establishment requests for the two PDU sessions, the PDU session establishment requests comprising respective information that identifies the active PDU session or a standby PDU session. In some of these examples, the determining which of the two PDU sessions is the active PDU session is based on the respective information included in at least one of the PDU session establishment requests.

[0087] In some examples, the requesting to establish the two PDU sessions comprises sending, to the UPF, the respective information that identifies the one of the two PDU sessions as the active PDU session for routing downlink traffic through the one of the two PDU sessions.

[0088] In some examples, the requesting to establish the two PDU sessions further comprises sending, to the UPF, the respective information included in the PDU session establishment requests.

[0089] In some examples, the sending the information included in the PDU session establishment request comprises sending, to the UPF, at least one N4 session establishment request to establish at least one N4 session for the two PDU sessions. In some of these examples, the at least one N4 session establishment request comprises the respective information included in at least one of the PDU session establishment requests.

[0090] In some examples, the sending the at least one N4 session establishment request comprises sending the at least one N4 session establishment request further comprising an indication that the two PDU sessions are for dual steering.

[0091] In some examples, the method 700 further includes receiving, from the UPF, a notification that indicates traffic detected on the one of the two PDU sessions. In some of these examples, the determining which of the two PDU sessions is the active session is based on the notification received from the UPF.

[0092] In some examples, the method 700 further includes subscribing to an event notification from the UPF to notify when traffic is detected on either of the two PDU sessions. In some of these examples, the receiving the notification comprises receiving the event notification that indicates traffic detected on the one of the two PDU sessions.

[0093] In some examples the method 700 further comprises initiating one or more operations of a service request procedure to activate the user plane resources of the other of the two PDU sessions to switch the other of the two PDU sessions to being the active PDU session, as shown at block 710 of FIG. 7B. The method includes determining to deactivate user plane resources of the one of the two PDU sessions as a standby PDU session, as shown at block 712. And the method includes initiating, based on the determining to deactivate the user plane resources of the other of the two PDU sessions, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions, as shown at block 714.

[0094] In some examples, the method 700 further includes sending, to the UPF, information that identifies the other of the two PDU sessions as the active PDU session for routing downlink traffic through the other of the two PDU sessions.

[0095] In some examples, the sending the information that identifies the other of the two PDU sessions as the active PDU session comprises sending, to the UPF, a N4 session modification request. In some of these examples, the N4 session modification request comprises the information that identifies the other of the two PDU sessions as the active PDU session.

[0096] FIGS. 8A and 8B are flowcharts illustrating various steps in a method 800 performed by a user plane function (UPF), according to various example implementations. The method includes receiving requests from a session management function (SMF) to establish two packet data unit (PDU) sessions for a dual steer device, as shown at block 802 of FIG. 8 A. The two PDU sessions comprise a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device. Traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session. The method includes determining which one of the two PDU sessions is the active PDU session, as shown at block 804. And the method includes routing downlink traffic through the one of the two PDU sessions as the active PDU session, as shown at block 806.

[0097] In some examples, the receiving the requests to establish the two PDU sessions comprises receiving, from the SMF, information that identifies the one of the two PDU sessions as the active PDU session. In some of these examples, the determining which of the two PDU sessions is the active PDU session is based on the information received from the SMF.

[0098] In some examples, the receiving the information that identifies the one of the two PDU sessions as the active PDU session comprises receiving, from the SMF, at least one N4 session establishment request to establish at least one N4 session for the two PDU sessions. In some of these examples, the at least one N4 session establishment request comprises the information that identifies the one of the two PDU sessions as the active PDU session.

[0099] In some examples, the receiving the at least one N4 session establishment request comprises receiving the at least one N4 session establishment request further comprising an indication that the two PDU sessions are for dual steering.

[0100] In some examples, the method 800 further includes receiving, from the SMF, information that identifies the other of the two PDU sessions as the active PDU session. In some of these examples, the routing the downlink traffic comprises routing the downlink traffic through the other of the two PDU sessions as the active PDU session.

[0101] In some examples, the receiving the information that identifies the other of the two PDU sessions as the active PDU session comprises receiving, from the SMF, a N4 session modification request. In some of these examples, the N4 session modification request comprises the information that identifies the other of the two PDU sessions as the active PDU session.

[0102] In some examples, the method 800 further includes detecting traffic on the one of the PDU sessions. In some of these examples, the determining which of the two PDU sessions is the active PDU session is based on the traffic detected on the one of the two PDU sessions.

[0103] In some examples, the method 800 further includes sending, to the SMF, a notification that indicates traffic detected on the one of the two PDU sessions.

[0104] In some examples, the method 800 further includes receiving, from the SMF, a request for a subscription to an event notification from the UPF to notify when traffic is detected on either of the two PDU sessions. In some of these examples, the sending the notification comprises receiving the event notification that indicates the traffic detected on the one of the two PDU sessions.

[0105] In some examples, the method 800 further includes detecting traffic on the other of the two PDU sessions in connection with a switch to the other of the two PDU sessions as the active PDU session. In some of these examples, the routing the downlink traffic comprises routing the downlink traffic through the other of the two PDU sessions as the active PDU session.

[0106] In some examples, the method 800 further includes receiving downlink traffic for the device when user plane resources on the two PDU sessions are deactivated, as shown at block 808 of FIG. 8B. In some of these examples, the method includes initiating, based on the receiving the downlink traffic, one or more operations of a procedure to activate the user plane resources of the one of the two PDU sessions, as shown at block 810. And the method includes routing the downlink traffic through the one of the two PDU sessions, as shown at block 812.

[0107] FIG. 9 is a flowchart illustrating various steps in a method 900 performed by a dual steer device, according to various example implementations. The method includes sending packet data unit (PDU) session establishment requests to request a session management function (SMF) to establish two packet data unit (PDU) sessions, as shown at block 902. The two PDU sessions comprise a first PDU session associated with a first, subscriber identity' of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device. Traffic for the dual steer device is to be steered via an active PDU session that is indicated in at least one of the PDU session establishment requests, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session. The method includes sending uplink traffic through the one of the two PDU sessions as the active PDU session, In some of these examples, user plane resources for the other of the two PDU sessions are deactivated, as shown at block 904. The method includes determining to switch to the other of the two PDU sessions to be the active PDU session, as shown at block 906. And the method includes initiating, based on the determining to switch, one or more operations of a procedure to activate the user plane resources of the other of the two PDU sessions, as shown at block 908,

[0108] In some examples, the dual steer device comprises a user equipment associated with the first subscriber identity and the second subscriber identity,

[0109] In some examples, the dual steer device comprises a first user equipment associated with the first subscriber identity, and a second user equipment associated with the second subscriber identity'.

[0110] 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, radio access node 202, 5GC 302, gNB 306, AMF 308, SMF 310, UPF 312, CU 314, DU 316, Dual Steer device 400, UE-l / SUPI-1 402A and / or UE-2 / SUPI-2 402B, 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.

[0111] According to some example implementations, at least some of the method 700 described with respect to FIGS. 7 A and 7B may be carried out by an apparatus comprising means for performing functions corresponding steps of the method. Similarly, at least some of the method 800 described with respect to FIGS. 8A and 8B may be carried out by an apparatus comprising means for performing functions corresponding steps of the method. And at least some of the method 900 described with respect to FIG. 9 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 SAIF, UPF or any suitable apparatus, such as a server, host or node. Other examples of a suitable apparatus may include a user equipment, user device, user terminal, dual steer device, or the like.

[0112] 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 disclosure. 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.

[0113] The processing circuitry 1002 may be composed of one or more processors alone 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 collection of electronic circuits some of which may be packaged as an integrated circuit or multiple 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).

[0114] 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.

[0115] 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 nonvolatile 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.

[0116] 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.

[0117] In addition to the memory 1004 (e.g., computer-readable storage medium), the processing circuitry7 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 user interfaces. The communications interface may be configured to transmit and / or receive information, such as to and / or from other apparatus(es), 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 (X l('), wireless NIC (AMC) or the like.

[0118] 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 examples 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.

[0119] 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.

[0120] 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.

[0121] 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, such that 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.

[0122] 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.

[0123] As explained above and reiterated below, the present disclosure includes, without limitation, the following example implementations.

[0124] Clause 1. An apparatus to implement a session management function (SMF), the apparatus comprising: at least one memory' configured to store instructions; and at least one processing circuitry / configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: request a user plane function (UPF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; determine which one of the two PDU sessions is the active PDU session; determine to deactivate user plane resources of the other of the two PDU sessions, and initiate, based on the determining to deactivate, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

[0125] Clause 2. The apparatus of clause 1, wherein the apparatus caused to request to establish the two PDU sessions comprises the apparatus caused to receive, from the dual steer device, PDU session establishment requests for the two PDU sessions, the PDU session establishment requests comprising respective information that identifies the active PDU session or a standby PDU session, and wherein the apparatus is caused to determine which of the two PDU sessions is the active PDU session based on the respective information included in at least one of the PDU session establishment requests.

[0126] Clause 3. The apparatus of clause 2, wherein the apparatus caused to request to establish the two PDU sessions comprises the apparatus caused to send, to the UPF, the respective information that identifies the one of the two PDU sessions as the active PDU session for routing downlink traffic through the one of the two PDU sessi ons,

[0127] Clause 4. The apparatus of clause 2 or clause 3, wherein the apparatus caused to request to establish the two PDU sessions further comprises the apparatus caused to send, to the UPF, the respective information included in the PDU session establishment requests.

[0128] Clause 5. The apparatus of clause 4, wherein the apparatus caused to send the information included in the PDU session establishment request comprises the apparatus caused to send, to the UPF, at least one N4 session establishment request to establish at least one N4 session for the two PDU sessions, wherein the at least one N4 session establishment request comprises the respective information included in at least one of the PDU session establishment requests.

[0129] Clause 6. The apparatus of clause 5, wherein the apparatus caused to send the at least one N4 session establishment request comprises the apparatus caused to send the at least one N4 session establishment request further comprising an indication that the two PDU sessions are for dual steering.

[0130] Clause 7. The apparatus of any of clauses 1 to 6, wherein the at least one processing circuitry' is configured to execute the instructions to cause the apparatus to further receive, from the UPF, a notification that indicates traffic detected on the one of the two PDU sessions, and wherein the apparatus is caused to determine which of the two PDU sessions is the active session based on the notification received from the UPF.

[0131] Clause 8. The apparatus of clause 7, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further subscribe to an event notification from the UPF to notify when traffic is detected on either of the two PDU sessions, and wherein the apparatus caused to receive the notification comprises the apparatus caused to receive the event notification that indicates traffic detected on the one of the two PDU sessions.

[0132] Clause 9. The apparatus of any of clauses 1 to 8, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further at least: initiate one or more operations of a service request procedure to activate the user plane resources of the other of the two PDU sessions to switch the other of the two PDU sessions to being the active PDU session; determine to deactivate user plane resources of the one of the two PDU sessions as a standby PDU session; and initiate, based on the determining to deactivate the user plane resources of the other of the two PDU sessions, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

[0133] Clause 10. The apparatus of clause 9, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further send, to the UPF, information that identifies the other of the two PDU sessions as the active PDU session for routing downlink traffic through the other of the two PDU sessions.

[0134] Clause 11. The apparatus of clause 10, wherein the apparatus caused to send the information that identifies the other of the two PDU sessions as the active PDU session comprises the apparatus caused to send, to the UPF, aN4 session modification request, wherein the N4 session modification request comprises the information that identifies the other of the two PDU sessions as the active PDU session.

[0135] Clause 12. An apparatus implemented by a session management function (SMF), the apparatus comprising: means for requesting an user plane function (UPF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; means for determining which one of the two PDU sessions is the active PDU session; means for determining to deactivate user plane resources of the other of the two PDU sessions; and means for initiating, based on the determining to deactivate, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

[0136] Clause 13. The apparatus of clause 12, wherein the means for requesting to establish the tw'O PDU sessions comprises means for receiving, from the dual steer device, PDU session establishment requests for the two PDU sessions, the PDU session establishment requests comprising respective information that identifies the active PDU session or a standby PDU session, and wherein the means for determining which of the tw'O PDU sessions is the active PDU session is based on the respective information included in at least one of the PDU session establishment requests,

[0137] Clause 14. The apparatus of clause 13, wherein the means for requesting to establish the two PDU sessions comprises means for sending, to the UPF, the respective information that identifies the one of the two PDU sessions as the active PDU session for routing downlink traffic through the one of the two PDU sessions.

[0138] Clause 15. The apparatus of clause 13 or clause 14, wherein the means for requesting to establish the two PDU sessions further comprises means for sending, to the UPF, the respective information included in the PDU session establishment requests.

[0139] Clause 16. The apparatus of clause 15, wherein the means for sending the information included in the PDU session establishment request comprises means for sending, to the UPF, at least one N4 session establishment request to establish at least one N4 session for the two PDU sessions, wherein the at least one N4 session establishment request comprises the respective information included in at least one of the PDU session establi shment requests.

[0140] Clause 17. The apparatus of clause 16, wherein the means for sending the at least one N4 session establishment request comprises means for sending the at least one Nz session establishment request further comprising an indication that the two PDU sessions are for dual steering.

[0141] Clause 18. The apparatus of any of clauses 12 to 17, wherein the apparatus further comprises means for receiving, from the UPF, a notification that indicates traffic detected on the one of the two PDU sessions, and wherein the means for determining which of the two PDU sessions is the active session is based on the notification received from the UPF.

[0142] Clause 19. The apparatus of clause 18, wherein the apparatus further comprises means for subscribing to an event notification from the UPF to notify when traffic is detected on either of the two PDU sessions, and wherein the means for receiving the notification comprises means for receiving the event notification that indicates traffic detected on the one of the two PDU sessions.

[0143] Clause 20. The apparatus of any of clauses 12 to 19 further comprising: means for initiating one or more operations of a service request procedure to activate the user plane resources of the other of the two PDU sessions to switch the other of the two PDU sessions to being the active PDU session; means for determining to deactivate user plane resources of the one of the two PDU sessions as a standby PDU session; and means for initiating, based on the determining to deactivate the user plane resources of the other of the two PDU sessions, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

[0144] Clause 21. The apparatus of clause 20, wherein the apparatus further comprises means for sending, to the UPF, information that identifies the other of the two PDU sessions as the active PDU session for routing downlink traffic through the other of the two PDU sessions.

[0145] Clause 22. The apparatus of clause 21, wherein the means for sending the information that identifies the other of the two PDU sessions as the active PDU session comprises means for sending, to the UPF, a N4 session modification request, wherein the N4 session modification request comprises the information that identifies the other of the two PDU sessions as the active PDU session.

[0146] Clause 23. A method performed by a session management function (SMF), the method comprising: requesting a user plane function (UPF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; determining which one of the two PDU sessions is the active PDU session; determining to deactivate user plane resources of the other of the two PDU sessions; and initiating, based on the determining to deactivate, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

[0147] Clause 24. The method of clause 23, wherein the requesting to establish the two PDU sessions comprises receiving, from the dual steer device, PDU session establishment requests for the two PDU sessions, the PDU session establishment requests comprising respective information that identifies the active PDU session or a standby PDU session, and wherein the determining which of the two PDU sessions is the active PDU session is based on the respective information included in at least one of the PDU session establishment requests.

[0148] Clause 25. The method of clause 24, wherein the requesting to establish the two PDU sessions comprises sending, to the UPF, the respective information that identifies the one of the two PDU sessions as the active PDU session for routing downlink traffic through the one of the two PDU sessions.

[0149] Clause 26. The method of clause 24 or clause 25, wherein the requesting to establish the two PDU sessions further comprises sending, to the UPF, the respective information included in the PDU session establishment requests.

[0150] Clause 27. The method of clause 26, wherein the sending the information included in the PDU session establishment request comprises sending, to the UPF, at least one N4 session establishment request to establish at least one N4 session for the two PDU sessions, wherein the at least one N4 session establishment request comprises the respective information included in at least one of the PDU session establishment requests.

[0151] Clause 28. The method of clause 27, wherein the sending the at least one N4 session establishment request comprises sending the at least one N4 session establishment request further comprising an indication that the two PDU sessions are for dual steering.

[0152] Clause 29. The method of any of clauses 23 to 28, wherein the method further comprises receiving, from the UPF, a notification that indicates traffic detected on the one of the two PDU sessions, and wherein the determining which of the two PDU sessions is the active session is based on the notification received from the UPF.

[0153] Clause 30. The method of clause 29, wherein the method further comprises subscribing to an event notification from the UPF to notify when traffic is detected on either of the two PDU sessions, and wherein the receiving the notification comprises receiving the event notification that indicates traffic detected on the one of the two PDU sessions.

[0154] Clause 31. The method of any of clauses 23 to 30 further comprising: initiating one or more operations of a service request procedure to activate the user plane resources of the other of the two PDU sessions to switch the other of the two PDU sessions to being the active PDU session; determining to deactivate user plane resources of the one of the two PDU sessions as a standby PDU session; and initiating, based on the determining to deactivate the user plane resources of the other of the two PDU sessions, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

[0155] Clause 32. The method of clause 31, wherein the method further comprises sending, to the UPF, information that identifies the other of the two PDU sessions as the active PDU session for routing downlink traffic through the other of the two PDU sessions.

[0156] Clause 33. The method of clause 32, wherein the sending the information that identifies the other of the two PDU sessions as the active PDU session comprises sending, to the UPF, a N4 session modification request, wherein the N4 session modification request comprises the information that identifies the other of the two PDU sessions as the active PDU session.

[0157] Clause 34. computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes a session management function (SMF) to at least: request a user plane function (UPF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first, subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; determine which one of the two PDU sessions is the active PDU session; determine to deactivate user plane resources of the other of the two PDU sessions; and initiate, based on the determining to deactivate, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

[0158] Clause 35. The computer-readable storage medium of clause 34, wherein the SMF caused to request to establish the two PDU sessions comprises the SMF caused to receive, from the dual steer device, PDU session establishment requests for the two PDU sessions, the PDU session establishment requests comprising respective information that identifies the active PDU session or a standby PDU session, and wherein the SMF is caused to determine which of the tw?o PDU sessions is the active PDU session based on the respective information included in at least one of the PDU session establishment requests.

[0159] Clause 36. The computer-readable storage medium of clause 35, wherein the SMF caused to request to establish the two PDU sessions comprises the SMF caused to send, to the UPF, the respective information that identifies the one of the two PDU sessions as the active PDU session for routing downlink traffic through the one of the two PDU sessions.

[0160] Clause 37. The computer-readable storage medium of clause 35 or clause 36, wherein the SMF caused to request to establish the two PDU sessions further comprises the SMF caused to send, to the UPF, the respective information included in the PDU session establishment requests.

[0161] Clause 38. The computer-readable storage medium of clause 37, wherein the SMF caused to send the information included in the PDU session establishment request comprises the SMF caused to send, to the UPF, at least one N4 session establishment request to establish at least one N4 session for the two PDU sessions, wherein the at least one N4 session establishment request comprises the respective information included in at least one of the PDU session establishment requests.

[0162] Clause 39. The computer-readable storage medium of clause 38, wherein the SMF caused to send the at least one N4 session establishment request comprises the SMF caused to send the at least one N4 session establishment request further comprising an indication that the two PDU sessions are for dual steering.

[0163] Clause 40. The computer-readable storage medium of any of clauses 34 to 39, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the SMF to further receive, from the UPF, a notification that indicates traffic detected on the one of the two PDU sessions, and wherein the SMF is caused to determine which of the two PDU sessions is the active session based on the notification received from the UPF.

[0164] Clause 41. The computer-readable storage medium of clause 40, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the SMF to further subscribe to an event notification from the UPF to notify when traffic is detected on either of the two PDU sessions, and wherein the SMF caused to receive the notification comprises the SMF caused to receive the event notification that, indicates traffic detected on the one of the two PDU sessions.

[0165] Clause 42. The computer-readable storage medium of any of clauses 34 to 41, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the SMF to further at least: initiate one or more operations of a service request procedure to activate the user plane resources of the other of the two PDU sessions to switch the other of the two PDU sessions to being the active PDU session; determine to deactivate user plane resources of the one of the two PDU sessions as a standby PDU session; and initiate, based on the determining to deactivate the user plane resources of the other of the two PDU sessions, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

[0166] Clause 43. The computer-readable storage medium of clause 42, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the SMF to further send, to the UPF, information that identifies the other of the two PDU sessions as the active PDU session for routing downlink traffic through the other of the two PDU sessions.

[0167] Clause 44. The computer-readable storage medium of clause 43, wherein the SMF caused to send the information that identifies the other of the two PDU sessions as the active PDU session comprises the SMF caused to send, to the UPF, a N4 session modification request, wherein theN4 session modification request comprises the information that identifies the other of the two PDU sessions as the active PDU session.

[0168] Clause 45. An apparatus comprising means for performing the method of any of clauses 23 to 33.

[0169] Clause 46. 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 23 to 33.

[0170] Clause 47. 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 23 to 33.

[0171] Clause 48. 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 23 to 33.

[0172] Clause 49. An apparatus to implement a user plane function (UPF), the apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: receive requests from a session management function (SMF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; determine which one of the two PDU sessions is the active PDU session; and route downlink traffic through the one of the two PDU sessions as the active PDU session.

[0173] Clause 50. The apparatus of clause 49, wherein the apparatus caused to receive the requests to establish the two PDU sessions comprises the apparatus caused to receive, from the SMF, information that identifies the one of the two PDU sessions as the active PDU session, and wherein the apparatus is caused to determine which of the two PDU sessions is the active PDU session based on the information received from the SMF.

[0174] Clause 51. The apparatus of clause 50, wherein the apparatus caused to receive the information that identifies the one of the tw'O PDU sessions as the active PDU session comprises the apparatus caused to receive, from the SMF, at least one N4 session establishment request to establish at least one N4 session for the two PDU sessions, wherein the at least one N4 session establishment request comprises the information that identifies the one of the two PDU sessions as the active PDU session.

[0175] Clause 52. The apparatus of clause 51, wherein the apparatus caused to receive the at least one N4 session establishment request comprises the apparatus caused to receive the at least one N4 session establishment request further comprising an indication that the two PDU sessions are for dual steering.

[0176] Clause 53. The apparatus of any of clauses 50 to 52, wherein the at least one processing circuitry' is configured to execute the instructions to cause the apparatus to further receive, from the SMF, information that, identifies the other of the two PDU sessions as the active PDU session, and wherein the apparatus caused to route the downlink traffic comprises the apparatus caused to route the downlink traffic through the other of the two PDU sessions as the active PDU session.

[0177] Clause 54. The apparatus of clause 53, wherein the apparatus caused to receive the information that identifies the other of the two PDU sessions as the active PDU session comprises the apparatus caused to receive, from the SMF, a N4 session modification request, wherein theN4 session modification request comprises the information that identifies the other of the two PDU sessions as the active PDU session.

[0178] Clause 55. The apparatus of any of clauses 49 to 54, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further detect traffic on the one of the PDU sessions, and wherein the apparatus is caused to determine which of the two PDU sessions is the active PDU session based on the traffic detected on the one of the two PDU sessions.

[0179] Clause 56. The apparatus of clause 55, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further send, to the SMF, a notification that indicates traffic detected on the one of the two PDU sessions.

[0180] Clause 57. The apparatus of clause 56, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further receive, from the SMF, a request for a subscription to an event notification from the UPF to notify when traffic is detected on either of the two PDU sessions, and wherein the apparatus caused to send the notification comprises the apparatus caused to receive the event notification that indicates the traffic detected on the one of the two PDU sessions.

[0181] Clause 58. The apparatus of any of clauses 55 to 57, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further detect traffic on the other of the two PDU sessions in connection with a switch to the other of the two PDU sessions as the active PDU session, and wherein the apparatus caused to route the downlink traffic comprises the apparatus caused to route the downlink traffic through the other of the two PDU sessions as the active PDU session.

[0182] Clause 59. The apparatus of any of clauses 49 to 58, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further at least.: receive downlink traffic for the device when user plane resources on the two PDU sessions are deactivated; initiate, based on the receiving the downlink traffic, one or more operations of a procedure to activate the user plane resources of the one of the two PDU sessions; and route the downlink traffic through the one of the two PDU sessions.

[0183] Clause 60. An apparatus to implement an user plane function (UPF), the apparatus comprising: means for receiving requests from a session management function (SMF) to establish two packet data unit. (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; means for determining which one of the two PDU sessions is the active PDU session; and means for routing downlink traffic through the one of the two PDU sessions as the active PDU session.

[0184] Clause 61. The apparatus of clause 60, wherein the means for receiving the requests to establish the two PDU sessions comprises means for receiving, from the SMF, information that identifies the one of the two PDU sessions as the active PDU session, and wherein the determining which of the two PDU sessions is the active PDU session is based on the information received from the SMF.

[0185] Clause 62. The apparatus of clause 61, wherein the means for receiving the information that identifies the one of the two PDU sessions as the active PDU session comprises means for receiving, from the SMF, at least one N4 session establishment request to establish at least one N4 session for the two PDU sessions, wherein the at least one N4 session establishment request comprises the information that identifies the one of the two PDU sessions as the active PDU session.

[0186] Clause 63. The apparatus of clause 62, wherein the means for receiving the at least one N4 session establishment request comprises means for receiving the at least one N4 session establishment request further comprising an indication that the two PDU sessions are for dual steering.

[0187] Clause 64. The apparatus of any of clauses 61 to 63, wherein the apparatus further comprises means for receiving, from the SMF, information that identities the other of the two PDU sessions as the active PDU session, and wherein the means for routing the downlink traffic comprises means for routing the downlink traffic through the other of the two PDU sessions as the active PDU session.

[0188] Clause 65. The apparatus of clause 64, wherein the means for receiving the information that identifies the other of the two PDU sessions as the active PDU session comprises means for receiving, from the SMF, a N4 session modification request, wherein the N4 session modification request comprises the information that, identifies the other of the tw?o PDU sessions as the active PDU session.

[0189] Clause 66. The apparatus of any of clauses 60 to 65, wherein the apparatus further comprises means for detecting traffic on the one of the PDU sessions, and wherein the means for determining which of the two PDU sessions is the active PDU session is based on the traffic detected on the one of the two PDU sessions.

[0190] Clause 67. The apparatus of clause 66, wherein the apparatus further comprises means for sending, to the SMF, a notification that indicates traffic detected on the one of the two PDU sessions.

[0191] Clause 68. The apparatus of clause 67, wherein the apparatus further comprises means for receiving, from the SMF, a request for a subscription to an event notification from the UPF to notify when traffi c is detected on either of the two PDU sessions, and wherein the means for sending the notification comprises means for receiving the event notification that indicates the traffic detected on the one of the two PDU sessions.

[0192] Clause 69. The apparatus of any of clauses 66 to 68, wherein the apparatus further comprises means for detecting traffic on the other of the two PDU sessions in connection with a switch to the other of the two PDU sessions as the active PDU session, and wherein the means for routing the downlink traffic comprises means for routing the downlink traffic through the other of the two PDU sessions as the active PDU session.

[0193] Clause 70. The apparatus of any of clauses 60 to 69 further comprising: means for receiving downlink traffic for the device when user plane resources on the two PDU sessions are deactivated; means for initiating, based on the receiving the downlink traffic, one or more operations of a procedure to activate the user plane resources of the one of the two PDU sessions; and means for routing the downlink traffic through the one of the two PDU sessions.

[0194] Clause 71. A method performed by a user plane function (UPF), the method comprising: receiving requests from a session management function (SMF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; determining which one of the two PDU sessi ons is the active PDU session; and routing downlink traffi c through the one of the two PDU sessions as the active PDU session.

[0195] Clause 72. The method of clause 71, wherein the receiving the requests to establish the two PDU sessions comprises receiving, from the SMF, information that identifies the one of the two PDU sessions as the active PDU session, and wherein the determining which of the two PDU sessions is the active PDU session is based on the information received from the SMF.

[0196] Clause 73. The method of clause 72, wherein the receiving the information that identifies the one of the two PDU sessions as the active PDU session comprises receiving, from the SMF, at least one N4 session establishment request to establish at least one N4 session for the two PDU sessions, wherein the at least one N4 session establishment-request comprises the information that identifies the one of the two PDU sessions as the active PDU session.

[0197] Clause 74. The method of clause 73, wherein the receiving the at least one N4 session establishment request comprises receiving the at least one N4 session establishment request further comprising an indication that the two PDU sessions are for dual steering.

[0198] Clause 75. The method of any of clauses 72 to 74, wherein the method further comprises receiving, from the SMF, information that identifies the other of the two PDU sessions as the active PDU session, and wherein the routing the downlink traffic comprises routing the downlink traffic through the other of the two PDU sessions as the active PDU session.

[0199] Clause 76. The method of clause 75, wherein the receiving the information that identifies the other of the two PDU sessions as the active PDU session comprises receiving, from the SMF, a N4 session modification request, wherein the N4 session modification request comprises the information that identifies the other of the two PDU sessions as the active PDU session.

[0200] Clause 77. The method of any of clauses 71 to 76, wherein the method further comprises detecting traffic on the one of the PDU sessions, and wherein the determining which of the trvo PDU sessions is the active PDU session is based on the traffic detected on the one of the two PDU sessions.

[0201] Clause 78. The method of clause 77, wherein the method further comprises sending, to the SMF, a notification that indicates traffic detected on the one of the two PDU sessions.

[0202] Clause 79. The method of clause 78, wherein the method further comprises receiving, from the SMF, a request for a subscription to an event notification from the UPF to notify when traffic is detected on either of the two PDU sessions, and wherein the sending the notification comprises receiving the event notification that indicates the traffic detected on the one of the two PDU sessions.

[0203] Clause 80. The method of any of clauses 77 to 79, wherein the method further comprises detecting traffic on the other of the two PDU sessions in connection with a switch to the other of the two PDU sessions as the active PDU session, and wherein the routing the downlink traffic comprises rou ting the downlink traffic through the other of the two PDU sessions as the active PDU session.

[0204] Clause 81. The method of any of clauses 71 to 80 further comprising: receiving downlink traffic for the device when user plane resources on the two PDU sessions are deactivated; initiating, based on the receiving the downlink traffic, one or more operations of a procedure to activate the user plane resources of the one of the two PDU sessions, and routing the downlink traffic through the one of the two PDU sessions.

[0205] Clause 82. A computer-readable storage medium that is non-transitory and having instructions stored therein that, in response to execution by at least one processing circuitry, causes a user plane function (UPF) to at least: receive requests from a session management function (SMF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; determine which one of the two PDU sessions is the active PDU session; and route downlink traffic through the one of the two PDU sessions as the active PDU session.

[0206] Clause 83. The computer-readable storage medium of clause 82, wherein the UPF caused to receive the requests to establish the two PDU sessions comprises the UPF caused to receive, from the SMF, information that identifies the one of the two PDU sessions as the active PDU session, and wherein the UPF is caused to determine which of the two PDU sessions is the active PDU session based on the information received from the SMF.

[0207] Clause 84. The computer-readable storage medium of clause 83, wherein the UPF caused to receive the information that identifies the one of the two PDU sessions as the active PDU session comprises the UPF caused to receive, from the SMF, at least one N4 session establishment request to establish at least one N4 session for the two PDU sessions, wherein the at least one N4 session establishment request comprises the information that identifies the one of the two PDU sessions as the active PDU session.

[0208] Clause 85. The computer-readable storage medium of clause 84, wherein the UPF caused to receive the at least one N4 session establishment request comprises the UPF caused to receive the at least one N4 session establishment request further comprising an indication that the two PDU sessions are for dual steering.

[0209] Clause 86. The computer-readable storage medium of any of clauses 83 to 85, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the UPF to further receive, from the SMF, information that identifies the other of the two PDU sessions as the active PDU session, and wherein the UPF caused to route the downlink traffic comprises the UPF caused to route the downlink traffic through the other of the two PDU sessions as the active PDU session.

[0210] Clause 87. The computer-readable storage medium of clause 86, wherein the UPF caused to receive the information that identifies the other of the two PDU sessions as the active PDU session comprises the UPF caused to receive, from the SMF, aN4 session modification request, wherein theN4 session modification request comprises the information that identifies the other of the two PDU sessions as the active PDU session.

[0211] Clause 88. The computer-readable storage medium of any of clauses 82 to 87, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the UPF to further detect traffic on the one of the PDU sessions, and wherein the UPF is caused to determine which of the two PDU sessions is the active PDU session based on the traffic detected on the one of the two PDU sessions.

[0212] Clause 89. The computer-readable storage medium of clause 88, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the UPF to further send, to the SMF, a notification that indicates traffic detected on the one of the two PDU sessions.

[0213] Clause 90. The computer-readable storage medium of clause 89, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the UPF to further receive, from the SMF, a request for a subscription to an event notification from the UPF to notify when traffic is detected on either of the two PDU sessions, and wherein the UPF caused to send the notification comprises the UPF caused to receive the event notification that indicates the traffic detected on the one of the two PDU sessions.

[0214] Clause 91. The computer-readable storage medium of any of clauses 88 to 90, wherein the computer-readable storage medium has further instractions stored therein that, in response to execution by the at least one processing circuitry, causes the UPF to further detect traffic on the other of the two PDU sessions in connection with a switch to the other of the two PDU sessions as the active PDU session, and wherein the UPF caused to route the downlink traffic comprises the UPF caused to route the downlink traffic through the other of the two PDU sessions as the active PDU session.

[0215] Clause 92. The computer-readable storage medium of any of clauses 82 to 91, wherein the computer-readable storage medium has further instructions stored therein that, in response to execution by the at least one processing circuitry, causes the UPF to further at least: receive downlink traffic for the device when user plane resources on the two PDU sessions are deactivated; initiate, based on the receiving the downlink traffic, one or more operations of a procedure to activate the user plane resources of the one of the two PDU sessions; and route the downlink traffic through the one of the two PDU sessions.

[0216] Clause 93. An apparatus comprising means for performing the method of any of clauses 71 to 81.

[0217] Clause 94. 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 71 to 81.

[0218] Clause 95. 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 71 to 81.

[0219] Clause 96. 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 71 to 81.

[0220] Clause 97. An apparatus implemented by a dual steer device, the apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory', and execute the instructions to cause the apparatus to at least: send packet data unit (PDU) session establishment requests to request a session management function (SMF) to establish two packet data unit (PDU) sessions, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session that is indicated in at least one of the PDU session establishment requests, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; send uplink traffic through the one of the two PDU sessions as the active PDU session, wherein user plane resources for the other of the two PDU sessions are deactivated; determine to switch to the other of the two PDU sessions to be the active PDU session; and initiate, based on the determining to switch, one or more operations of a procedure to activate the user plane resources of the other of the two PDU sessions.

[0221] Clause 98. The apparatus of clause 97, wherein the dual steer device comprises a user equipment associated with the first subscriber identity and the second subscriber identity.

[0222] Clause 99. The apparatus of clause 97 or clause 98, wherein the dual steer device comprises a first user equipment associated with the first subscriber identity, and a second user equipment associated with the second subscriber identity.

[0223] Clause 100. An apparatus implemented by a dual steer device, the apparatus comprising: means for sending packet data unit (PDU) session establishment requests to request a session management function (SMF) to establish two packet data unit (PDU) sessions, the tw?o PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session that is indicated in at least one of the PDU session establishment requests, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; means for sending uplink traffic through the one of the two PDU sessions as the active PDU session, wherein user plane resources for the other of the two PDU sessions are deactivated, means for determining to switch to the other of the two PDU sessions to be the active PDU session; and means for initiating, based on the determining to switch, one or more operations of a procedure to activate the user plane resources of the other of the two PDU sessions.

[0224] Clause 101. The apparatus of clause 100 or clause 100, wherein the dual steer device comprises an user equipment associated with the first subscriber identity and the second subscriber identity.

[0225] Clause 102. The apparatus of clause 100 or clause 101, wherein the dual steer device comprises a first user equipment associated with the first subscriber identity, and a second user equipment associated with the second subscriber identity.

[0226] Clause 103. A method performed by a dual steer device, the method comprising: sending packet data unit (PDU) session establishment requests to request a session management function (SMF) to establish two packet data unit (PDU) sessions, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session that is indicated in at least one of the PDU session establishment requests, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first. PDU session and the second PDU session; sending uplink traffic through the one of the two PDU sessions as the active PDU session, wherein user plane resources for the other of the two PDU sessions are deactivated; determining to switch to the other of the two PDU sessions to be the active PDU session; and initiating, based on the determining to switch, one or more operations of a procedure to activate the user plane resources of the other of the two PDU sessions.

[0227] Clause 104. The method of clause 103 or clause 103, wherein the dual steer device comprises a user equipment associated with the first subscriber identity and the second subscriber identity.

[0228] Clause 105. The method of clause 103 or clause 104, wherein the dual steer device comprises a first user equipment associated with the first subscriber identity, and a second user equipment associated with the second subscriber identity.

[0229] Clause 106. A computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes a dual steer device to at least: send packet data unit (PDU) session establishment requests to request a session management function (SMF) to establish two packet data unit (PDU) sessions, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session that is indicated in at least one of the PDU session establishment requests, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session; send uplink traffic through the one of the two PDU sessions as the active PDU session, wherein user plane resources for the other of the two PDU sessions are deactivated; determine to switch to the other of the two PDU sessions to be the active PDU session; and initiate, based on the determining to switch, one or more operations of a procedure to activate the user plane resources of the other of the two PDU sessions.

[0230] Clause 107. The computer-readable storage medium of clause 106 or clause 106, wherein the dual steer device comprises a user equipment associated with the first subscriber identity and the second subscriber identity.

[0231] Clause 108. The computer-readable storage medium of clause 106 or clause 107, wherein the dual steer device comprises a first user equipment associated with the first subscriber identity, and a second user equipment associated with the second subscriber identity.

[0232] Clause 109. An apparatus comprising means for performing the method of any of clauses 103 to 105.

[0233] Clause 110. 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 103 to 105.

[0234] Clause 111. 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 103 to 105.

[0235] Clause 112. 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 103 to 105.

[0236] 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 5 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

1. A method performed by a session management function (SMF), the method comprising:requesting a user plane function (UPF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session;determining which one of the two PDU sessions is the active PDU session;determining to deactivate user plane resources of the other of the two PDU sessions; andinitiating, based on the determining to deactivate, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions.

2. The method as claimed in claim 1, wherein the requesting to establish the two PDU sessions comprises receiving, from the dual steer device, PDU session establishment requests for the two PDU sessions, the PDU session establishment requests comprising respective information that identifies the active PDU session or a standby PDU session, andwherein the determining which of the two PDU sessions is the active PDU session is based on the respective information included in at least one of the PDU session establishment requests.

3. The method as claimed in claim 2, wherein the requesting to establish the two PDU sessions comprises sending, to the UPF, the respective information that identifies the one of the two PDU sessions as the active PDU session for routing downlink traffic through the one of the two PDU sessions.

4. The method as claimed in claim 2 or claim 3, wherein the requesting to establish the two PDU sessions further comprises sending, to the UPF, the respective information included in the PDU session establishment requests.

5. The method as claimed in claim 4, wherein the sending the information included in the PDU session establishment request comprises sending, to the UPF, at least one N4 session establishment request to establish at least one N4 session for the two PDU sessions, wherein the at least one N4 session establishment request comprises the respective information included in at least one of the PDU session establishment requests.

6. The method as claimed in claim 5, wherein the sending the at least one N4 session establishment request comprises sending the at least one N4 session establishment request further comprising an indication that the two PDU sessions are for dual steering.

7. The method as claimed in any of claims 1 to 6, wherein the method further comprises receiving, from the UPF, a notification that indicates traffic detected on the one of the two PDU sessions, andwherein the determining which of the two PDU sessions is the active session is based on the notification received from the UPF.

8. The method as claimed in claim 7, wherein the method further comprises subscribing to an event notification from the UPF to notify when traffic is detected on either of the two PDU sessions, andwherein the receiving the notification comprises receiving the event notification that indicates traffic detected on the one of the two PDU sessions.

9. The method as claimed in any of claims 1 to 8, wherein further comprising: initiating one or more operations of a service request procedure to activate the user plane resources of the other of the two PDU sessions to switch the other of the two PDU sessions to being the active PDU session;determining to deactivate user plane resources of the one of the two PDU sessions as a standby PDU session; andinitiating, based on the determining to deactivate the user plane resources of the other of the two PDU sessions, one or more operations of a procedure to deactivate the user plane resources of the other of the two PDU sessions10. The method as claimed in claim 9, wherein the method further comprises sending, to the UPF, information that identifies the other of the two PDU sessions as the active PDU session for routing downlink traffic through the other of the two PDU sessions.

11. The method as claimed in claim 10, wherein the sending the information that identifies the other of the two PDU sessions as the active PDU session comprises sending, to the UPF, a N4 session modification request, wherein the N4 session modification request comprises the information that identifies the other of the two PDU sessions as the active PDU session.

12. An apparatus comprising means for performing the method as claimed in any of claims 1 to 11.

13. A method performed by a user plane function (UPF), the method comprising:receiving requests from a session management function (SMF) to establish two packet data unit (PDU) sessions for a dual steer device, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session;determining which one of the two PDU sessions is the active PDU session; and routing downlink traffic through the one of the two PDU sessions as the active PDU session.

14. The method as claimed in claim 13, wherein the receiving the requests to establish the two PDU sessions comprises receiving, from the SMF, information that identifies the one of the two PDU sessions as the active PDU session, andwherein the determining which of the two PDU sessions is the active PDU session is based on the information received from the SMF.

15. The method as claimed in claim 14, wherein the receiving the information that identifies the one of the two PDU sessions as the active PDU session comprises receiving, from the SMF, at least one N4 session establishment request to establish at least one N4 session for the two PDU sessions, wherein the at least one N4 session establishment request comprises the information that identifies the one of the two PDU sessions as the active PDU session.

16. The method as claimed in claim 15, wherein the receiving the at least one N4 session establishment request comprises receiving the at least one N4 session establishment request further comprising an indication that the two PDU sessions are for dual steering.

17. The method as claimed in any of claims 14 to 16, wherein the method further comprises receiving, from the SMF, information that identifies the other of the two PDU sessions as the active PDU session, andwherein the routing the downlink traffic comprises routing the downlink traffic through the other of the two PDU sessions as the active PDU session.

18. The method as claimed in claim 17, wherein the receiving the information that identifies the other of the two PDU sessions as the active PDU session comprises receiving, from the SMF, a N4 session modification request, wherein the N4 session modification request comprises the information that identifies the other of the two PDU sessions as the active PDU session.

19. The method as claimed in any of claims 13 to 18, wherein the method further comprises detecting traffic on the one of the PDU sessions, andwherein the determining which of the two PDU sessions is the active PDU session is based on the traffic detected on the one of the two PDU sessions.

20. The method as claimed in claim 19, wherein the method further comprises sending, to the SMF, a notification that indicates traffic detected on the one of the two PDU sessions.

21. The method as claimed in claim 20, wherein the method further comprises receiving, from the SMF, a request for a subscription to an event notification from the UPF to notify when traffic is detected on either of the two PDU sessions, andwherein the sending the notification comprises receiving the event notification that indicates the traffic detected on the one of the two PDU sessions.

22. The method as claimed in any of claims 19 to 21, wherein the method further comprises detecting traffic on the other of the two PDU sessions in connection with a switch to the other of the two PDU sessions as the active PDU session, andwherein the routing the downlink traffic comprises routing the downlink traffic through the other of the two PDU sessions as the active PDU session.

23. The method as claimed in any of claims 13 to 22 further comprising: receiving downlink traffic for the device when user plane resources on the two PDU sessions are deactivated;initiating, based on the receiving the downlink traffic, one or more operations of a procedure to activate the user plane resources of the one of the two PDU sessions; androuting the downlink traffic through the one of the two PDU sessions.

24. An apparatus comprising means for performing the method as claimed in any of claims 13 to 23.

25. A method performed by a dual steer device, the method comprising: sending packet data unit (PDU) session establishment requests to request a session management function (SMF) to establish two packet data unit (PDU) sessions, the two PDU sessions comprising a first PDU session associated with a first subscriber identity of the dual steer device and a second PDU session associated with a second subscriber identity of the dual device, wherein traffic for the dual steer device is to be steered via an active PDU session that is indicated in at least one of the PDU session establishment requests, the active PDU session comprising the first PDU session or the second PDU session and switchable between the first PDU session and the second PDU session;sending uplink traffic through the one of the two PDU sessions as the active PDU session, wherein user plane resources for the other of the two PDU sessions are deactivated;determining to switch to the other of the two PDU sessions to be the active PDU session; andinitiating, based on the determining to switch, one or more operations of a procedure to activate the user plane resources of the other of the two PDU sessions.

26. The method as claimed in claim 25, wherein the dual steer device comprises a user equipment associated with the first subscriber identity and the second subscriber identity.

27. The method as claimed in claim 25 or claim 26, wherein the dual steer device comprises a first user equipment associated with the first subscriber identity, and a second user equipment associated with the second subscriber identity.

28. An apparatus comprising means for performing the method as claimed in any of claims 25 to 27.s

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