WO2025212764A1

WO2025212764A1 - Dual steer session management

Info

Publication number: WO2025212764A1
Application number: PCT/US2025/022737
Authority: WO
Inventors: Vivek G Gupta; Anikethan Ramakrishna VIJAYA KUMAR; Haijing Hu; Nirlesh KOSHTA; Sridhar Prakasam
Original assignee: Apple Inc
Current assignee: Apple Inc
Priority date: 2024-04-02
Filing date: 2025-04-02
Publication date: 2025-10-09
Anticipated expiration: 2026-10-02

Abstract

An apparatus configured to generate a first request message to establish a first Protocol Data Unit (PDU) session with a first access network, wherein the first request message comprises an indication that a dual steer functionality is supported, process a first accept message indicating the first PDU session is established with the first access network, wherein the first accept message further comprises a PDU session identification (ID) for the first PDU session, generate a second request message to establish a second PDU session with a second access network, wherein the second request message comprises an indication that the dual steer functionality is supported and the PDU session ID for the first PDU session and process a second accept message indicating the second PDU session is established with the second access network, wherein the first and second sessions are associated PDU sessions of the dual steer functionality.

Description

Dual Steer Session Management

Inventors: Vivek G Gupta, Anikethan Ramakrishna Vijaya Kumar, Haijing Hu, Nirlesh Koshta and Sridhar Prakasam

Priority/Incorporation By Reference

[ 0001 ] This application claims priority to U.S. Provisional Application Serial No. 63/573,088 filed on April 2, 2024, and entitled “Dual Steer Session Management,” the entirety of which is incorporated by reference herein.

Background

[ 0002 ] A user equipment (UE) may establish a connection to multiple different networks or types of networks. Some UEs and networks support multiple access (MA). UEs that support MA may be referred to as dual steer UEs. In Third Generation Partnership (3GPP) networks such as 5G New Radio (5GNR) networks, Long Term Evolution (LTE) networks, a UE may request the network to set up an MA session for the UE through the use of a Multiple Access Dual Steer Protocol Data Unit (MADS-PDU). The typical use of an MADS-PDU session is for access to a 3GPP network and another type of network (e g., a Wi-Fi network). There is a desire to have the multiple networks be 3 GPP type networks. However, there are no current procedures to set up and manage MADS-PDU sessions when both access networks are 3GPP type networks.

Summary

[ 0003 ] Some example embodiments are related to an apparatus having processing circuitry configured to generate, for transmission to a first access network, a first request message to establish a first Protocol Data Unit (PDU) session with the first access network, wherein the first request message comprises an indication that a dual steer functionality is supported, process, based on signaling received from the first access network, a first accept message indicating the first PDU session is established with the first access network, wherein the first accept message further comprises a PDU session identification (ID) for the first PDU session, generate, for transmission to a second access network, a second request message to establish a second PDU session with the second access network, wherein the second request message comprises an indication that the dual steer functionality is supported and the PDU session ID for the first PDU session and process, based on signaling received from the second access network, a second accept message indicating the second PDU session is established with the second access network, wherein the first PDU session and the second PDU session are associated PDU sessions of the dual steer functionality.

[0004 ] Other example embodiments are related io a method for processing, based on signaling received from a first user equipment (UE) of a dual steer functionality UE, a first request message to establish a first Protocol Data Unit (PDU) session with a first access network, wherein the first request message comprises an indication that the first UE supports a dual steer functionality, selecting a session management function (SMF) and a user plane function (UPF) to establish the first PDU session with the first UE, reporting an SMF identification (ID) of the SMF to a Unified Data Management (UDM) function and generating, for transmission to the first UE, a first accept message indicating the first PDU session is established with the first access network, wherein the first accept message further comprises a PDU session identification (ID) for the first PDU session.

[ 0005 ] Still further example embodiments are related to a method for processing, based on signaling received from a first user equipment (UE) of a dual steer functionality UE, a first request message to establish a first Protocol Data Unit (PDU) session with a first access network, wherein the first request message comprises an indication that a dual steer functionality is supported and Session identification (ID) of a second PDU session associated with the dual steer functionality UE, determining a Session Management Function (SMF) hosting the second PDU session based on a mapping of a SMF ID of the SMF that is hosting a second PDU session and the Session ID stored in a Unified Data Management (UDM) function, selecting the SMF hosting the second PDU session to establish the first PDU session with the first UE and generating, for transmission to the first UE, an accept message indicating the first PDU session is established with the first access network. Brief Description of the Drawings

[ 0006 ] Fig. 1 shows an example network arrangement according to various example embodiments.

[ 0007 ] Fig. 2 shows an example user equipment (UE) according to various example embodiments.

[ 0008 ] Fig. 3 shows an example base station according to various example embodiments.

[ 0009 ] Fig. 4 shows an example registration procedure for a dual steer UE according to various example embodiments.

[ 0010 ] Fig. 5 shows an example session management procedure for a dual steer UE according to various example embodiments.

[ 0011 ] Fig. 6 shows a second example session management procedure for a dual steer UE according to various example embodiments.

[ 0012 ] Fig. 7 shows an end-to-end call flow for session management procedures for a home routed MADS-PDU session according to various example embodiments.

[ 0013] Fig. 8 shows an end-to-end call flow for session management procedures for handoff to a second leg of a home routed MADS-PDU session according to various example embodiments.

[ 0014 ] Fig. 9 shows an end-to-end call flow for session management procedures for a local breakout MADS-PDU session according to various example embodiments.

[ 0015 ] Fig. 10 shows a home routed architecture diagram for dual steer support for a PDU session handover according to various example embodiments. [ 0016] Fig. 11 shows an alternative home routed architecture diagram for dual steer support for a PDU session handover according to various example embodiments.

[ 0017 ] Fig. 12 shows a home routed architecture diagram for dual steer support for a MADS-PDU session handover according to various example embodiments.

[ 0018 ] Fig. 13 shows an alternative home routed architecture diagram for dual steer support for an MADS-PDU session handover according to various example embodiments.

[ 0019] Fig. 14 shows a local breakout architecture diagram for dual steer support for an MADS-PDU session according to various example embodiments.

[ 0020 ] Fig. 15 shows an alternative local breakout architecture diagram for dual steer support for an MADS-PDU session according to various example embodiments.

[ 0021 ] Fig. 16 shows a local breakout architecture diagram for dual steer support for an MADS-PDU session handover according to various example embodiments.

[ 0022 ] Fig. 17 shows an alternative local breakout architecture diagram for dual steer support for an MADS-PDU session handover according to various example embodiments.

[ 0023] Fig. 18 shows an example layer diagram for a dual steer UE having a single subscriber identity module (SIM) with a non-access stratum (NAS) layer instantiated according to various example embodiments.

[ 0024 ] Fig. 19 shows an example layer diagram for a dual steer UE having a single SIM with a NAS layer, an access stratum (AS) layer and layer 2 instantiated according to various example embodiments. [ 0025 ] Fig. 20 shows an example layer diagram for a dual steer UE having dual SIM with a NAS layer, an access stratum (AS) layer and layer 2 instantiated according to various example embodiments.

[ 0026] Fig. 21 shows an example layer diagram for a dual steer UE having two separate physical UEs according to various example embodiments.

[ 0027 ] Fig. 22 shows an example of a 5G Session Management (5GSM) Capability IE according to various example embodiments.

[ 0028 ] Figs. 23 A-C show an example of a dual steer container according to various example embodiments.

[ 0029] Fig. 24 shows an example of a dual steer IE that indicates dual steer specific information from a UE to the network or from the network to the UE according to various example embodiments.

[ 0030 ] Fig. 25 shows an example of a PDU Session Establishment Request sent by a UE to the network to initiate establishment of a PDU session according to various example embodiments.

[ 0031 ] Fig. 26 shows an example of a PDU Session Establishment Accept message sent by the network to a UE to indicate successful establishment of a PDU session according to various example embodiments.

[ 0032 ] Fig. 27 shows an example of a PDU Session Establishment Reject message sent by the network to a UE to indicate unsuccessful establishment of a PDU session according to various example embodiments.

[ 0033 ] Fig. 28 shows an example of a PDU Session Modification Request sent by the UE to request a modification of a PDU session according to various example embodiments. [ 0034 ] Fig. 29 shows an example of a PDU Session Modification Command message sent by the network to the UE indicating a modification of a PDU session according to various example embodiments.

[ 0035 ] Fig. 30 shows an example of a PDU Session Release Request sent by the UE to the network to request a release of a PDU session according to various example embodiments.

[ 0036 ] Fig. 31 shows an example of a PDU Session Release Command sent by the network to the UE to indicate a release of a PDU session according to various example embodiments.

Detailed Description

[ 0037 ] The example embodiments may be further understood with reference to the following description and the related appended drawings, wherein like elements are provided with the same reference numerals. The example embodiments relate to session management procedures for a user equipment (UE) that is dual steer capable. Specifically, the session management procedures relate to a scenario where both access networks are 3 GPP type networks.

[ 0038 ] The example embodiments are described with regard to a UE. However, reference to a UE is merely provided for illustrative purposes. The example embodiments may be utilized with any electronic component that may establish a connection to an accessory device and is configured with the hardware, software, and/or firmware to exchange information and data with accessory devices. Therefore, the UE as described herein is used to represent any electronic component.

[ 0039 ] The example embodiments are also described with reference to a 5G New Radio (NR) network. However, the example embodiments may also be implemented in other types of networks, including but not limited to LTE networks, future evolutions of the cellular protocol (e g., 5G-advanced networks, 6G networks, etc.), or any other type of network. [ 0040 ] The example embodiments are related to dual steering between two 3GPP networks. A dual steer UE is capable of steering and switching user traffic between two 3GPP access networks connected to the same or different public land mobile networks (PLMN). The dual steer UE may be a single UE for non-simultaneous transmission, or two separate UEs for simultaneous transmission. For example, the subscriber of the dual steer UE may have two subscriptions and identifiers (e.g., subscription permanent identifier (SUP I)), sharing one subscription profile from the same operator. At any given time, the dual steer UE may transmit all traffic of a service on only one of the two 3GPP accesses.

[ 0041 ] A UE may register with 3GPP access network either in a single registration mode or in a dual registration mode. The UE may provide the appropriate credentials in the registration message such as a Fifth Generation Globally Unique Temporary Identifier (5G-GUTI) if the UE has one available to use, or a Subscription Concealed Identifier (SUCI) or Permanent Equipment Identifier (PEI).

[ 0042 ] The UE may also register with a non-Third Generation Partnership Project (3GPP) access, to which single/dual registration modes are not applicable. For non-3GPP access registration, the UE can provide a 5G-GUTI if available or SUCI as credentials. The UE can register separately for 3GPP access and non-3GPP access, as the network only knows which access type is being used based on how the registration request is received over that particular access. The 3GPP access registration and non-3GPP access registration share the same 5G-GUTI identifier when registering on the same Public Land Mobile Network (PLMN). The registrations have different 5G-GUTIs when registering on different PLMNs. The UE may register with different Access and Mobility Management Function (AMF) entities depending on the deployment. The UE and network may also exchange Dual Steer capability information (DualSteer-ST: comprising supported Dual Steer steering functionality and steering modes) as part of the Fifth Generation Session Management (5GSM) capability exchange during Protocol Data Unit (PDU) activation or modification. [ 0043 ] As stated above, the subscriber of the dual steer UE may have two subscriptions/SUPIs, sharing one subscription profile from the same operator. For any particular service, at any given time, the dual steer UE may transmit all traffic of that service using only a single 3GPP access network. The example embodiments consider the following example scenarios of two 3GPP type networks. The example embodiments include an access network connected to a 3GPP core network and different combinations of these are permissible. For simplicity these combinations may be referred to as an access network. In a first scenario, two NR/5GC accesses in a single PLMN (HPLMN or VPLMN) with each access being NR terrestrial network (TN) or NR non-terrestrial network(NTN). In a second scenario, two NR/5GC accesses in two different PLMNs (including two visited PLMNs (VPLMNs) or a VPLMN and the home PLMN (HPLMN)) with each access being NR TN or NR NTN. In a third scenario, NR/5GC access and Evolved UMTS Terrestrial Radio Access (E-UTRA)/Evolved Packet Core (EPC) access in two different PLMNs (including two VPLMNs or a VPLMN and the HPLMN). In a fourth scenario, NR/5GC access and E-UTRA/EPC access in a single PLMN (HPLMN or VPLMN). In a fifth scenario, Public Network Integrated-Non-Public Network (PNI-NPN) (integrated with the HPLMN or integrated with the VPLMN) and PLMN access (TN/NTN plus TN or NTN). This scenario assumes only non-simultaneous transmission. The example embodiments are not limited to these example scenarios. These example scenarios are only provided as examples of different types of dual steer environments where the example embodiments may be used.

[ 0044 ] There may be various aspects to supporting dual steer UEs, including, but not limited to the overall architecture and function enhancements to 5GS to support a dual steer UEs, enhancing subscription aspects for dual steer UEs, impacts to the registration procedure for dual steer UEs, enhancing network policies provided by the HPLMN to the dual steer UEs and within the network to support dual steer UEs.

[ 0045 ] The example embodiments are related to the aspect of enhancing session management procedures for initial steering and potential subsequent switching between the different access networks (e.g., as described above) for dual steer UEs. These example embodiments will be described in greater detail below. [ 0046] Fig. 1 shows an example network arrangement 100 according to various example embodiments. The example network arrangement 100 includes a UE 110. The UE 110 may be any type of electronic component that is configured to communicate via a network, e.g., mobile phones, tablet computers, desktop computers, smartphones, embedded devices, wearables, Internet of Things (loT) devices, etc. An actual network arrangement may include any number of UEs being used by any number of users. Thus, the example of one UE 110 is merely provided for illustrative purposes. The UE 110 is a dual steer capable device as will be described in greater detail below.

[ 0047 ] The UE 110 may be configured to communicate with one or more networks. In the example of the network arrangement 100, the UE 110 may wirelessly communicate with two 5G NR radio access networks (RANs) 120 and 122. However, the UE 110 may also communicate with other types of networks (e.g., 5G cloud RAN, a next generation RAN (NG- RAN), a legacy cellular network, etc.) and the UE 110 may also communicate with networks over a wired connection. Some example scenarios of different types of access networks with which the UE may establish an MADS-PDU were described above. Thus, the use of two 5G NR RANs is only an example. With regard to the example embodiments, the UE 110 may establish a connection with the 5G NR RANs 120 and 122. Therefore, the UE 110 may have a 5G NR chipset to communicate with the NR RANs 120 and 122.

[ 0048 ] The 5G NR RANs 120 and 122 may be portions of a cellular network that may be deployed by a network carrier (e.g., Verizon, AT&T, T-Mobile, etc.). The RANs 120 and 122 may include cells or base stations that are configured to send and receive traffic from UEs that are equipped with the appropriate cellular chip set. In this example, the 5G NR RAN 120 includes the gNB 120A and the 5G NR RAN 122 includes the gNB 122A. However, reference to a gNB is merely provided for illustrative purposes, any appropriate base station or cell may be deployed (e.g., Node Bs, eNodeBs, HeNBs, eNBs, gNBs, gNodeBs, macrocells, microcells, small cells, femtocells, etc.). [ 0049] Any association procedure may be performed for the UE 110 to connect to the 5G NR RANs 120 and 122. For example, as discussed above, the 5G NR RANs 120 and 122 may be associated with a particular network carrier where the UE 110 and/or the user thereof has a contract and credential information (e.g., stored on a SIM card). Upon detecting the presence of the 5G NR RANs 120 and 122, the UE 110 may transmit the corresponding credential information to associate with the 5G NR RANs 120 and 122. More specifically, the UE 110 may associate with a specific cell (e.g., gNB 120A and/or gNB 122A). An example registration procedure for dual access is described below.

[ 0050 ] The network arrangement 100 also includes a cellular core network 130, the Internet 140, an IP Multimedia Subsystem (IMS) 150, and a network services backbone 160. The cellular core network 130 manages the traffic that flows between the cellular network and the Internet 140. The IMS 150 may be generally described as an architecture for delivering multimedia services to the UE 110 using the IP protocol. The IMS 150 may communicate with the cellular core network 130 and the Internet 140 to provide the multimedia services to the UE 110. The network services backbone 160 is in communication either directly or indirectly with the Internet 140 and the cellular core network 130. The network services backbone 160 may be generally described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a suite of services that may be used to extend the functionalities of the UE 1 10 in communication with the various networks.

[ 0051 ] The cellular core network 130 may comprise one or more network functions. In the example of Fig. 1, the cellular core network 130 comprises an Access and Mobility Management Function (AMF) 131, Session Management Function (SMF) 132, a User Plane Function (UPF) 133, a Unified Data Management (UDM) function 134 and a Policy Control Function (PCF) 135. The cellular core network may comprise multiple instances of each of these functions.

[ 0052 ] The AMF 131 may perform operations related to mobility management such as, but not limited to, paging, non-access stratum (NAS) management and registration procedure management between the UE 110 and the core network 130. The AMF 131 may be equipped with one or more communication interfaces (e.g., Nl, N2, etc.) to communicate directly or indirectly with other network components (e.g., network functions, RANs, UEs, etc.). The example embodiments are not limited to an AMF that performs the above referenced operations. Further, reference to a single AMF 131 is merely for illustrative purposes, an actual network arrangement may include any appropriate number of AMFs. The AMF 131 may also communicate directly with the SMF 132. For example, the AMF 131 may communicate with the SMF 132 over a Nl 1 interface.

[ 0053 ] The SMF 132 may perform operations related to session management such as, but not limited to, session establishment, session release, IP address allocation, policy and quality of service (QoS) enforcement, etc. The SMF 132 may be equipped with one or more communication interfaces (e.g., Ni l, etc.) to communicate directly or indirectly with other network components (e.g., network functions, RANs, UEs, etc.). The example embodiments are not limited to an SMF that performs the above referenced operations. Further, reference to a single SMF 132 is merely for illustrative purposes, an actual network arrangement may include any appropriate number of SMFs.

[ 0054 ] The UPF 133 performs operations related packet data unit (PDU) session management and other types of data flow management. For example, the UPF 133 may facilitate a connection between the UE 110 and a data network (e.g., Internet 140) via a N6 interface. The UPF 133 may be equipped with one or more communication interfaces (e.g., N3, N4, N6, etc.) to communicate directly or indirectly with other network components (e.g., network functions, RANs, UEs, etc.). The example embodiments are not limited to a UPF that performs the above referenced operations. Further, reference to a single UPF 133 is merely for illustrative purposes, an actual network arrangement may include any appropriate number of UPFs.

[ 0055 ] The UDM 134 manages data for operations such as access authorization, user registration, and data network profiles. The UDM 134 also manages subscriber data. The example embodiments are not limited to a UDM that performs the above referenced operations. Further, reference to a single UDM 134 is merely for illustrative purposes, an actual network arrangement may include any appropriate number of UDMs. [ 0056 ] The PCF 135 may perform operations related to the control plane such as, but not limited to, managing policy rules for control plane functions including network slicing, roaming and mobility management. The PCF 135 may be equipped with one or more communication interfaces (e.g., N7, etc.) to communicate directly or indirectly with other network components (e.g., network functions, RANs, UEs, etc.). The example embodiments are not limited to an PCF that performs the above referenced operations. Further, reference to a single PCF 135 is merely for illustrative purposes, an actual network arrangement may include any appropriate number of PCFs.

[ 0057 ] The operations performed by the network functions in the example embodiments related to dual steer capabilities are described in greater detail below.

[ 0058 ] Fig. 2 shows an example UE 110 according to various example embodiments. The UE 110 will be described with regard to the network arrangement 100 of Fig. 1. The UE 110 may represent any electronic device and may include a processor 205, a memory arrangement 210, a display device 215, an input/output (I/O) device 220, a transceiver 225, and other components 230. The other components 230 may include, for example, an audio input device, an audio output device, a battery that provides a limited power supply, a data acquisition device, ports to electrically connect the UE 110 to other electronic devices, sensors to detect conditions of the UE 110, etc.

[ 0059 ] The processor 205 may be configured to execute a plurality of engines for the UE 110. For example, the engines may include a Dual Steer engine 235 for performing operations related to MADS-PDU session management. For example, the Dual Steer engine 235 may include logic and/or circuitry that requests establishment of an MADS-PDU session, requests modification of an MADS-PDU session, measures link quality on different legs of the MADS- PDU session, steers or switches traffics between different legs of the MADS-PDU session, etc. Each of these example operations will be described in more detail below. [ 0060 ] The above referenced engine 235 being applications (e.g., programs) executed by the processor 205 is only an example. The functionality associated with the engines may also be represented as a separate incorporated component of the UE 110 or may be a modular component coupled to the UE 110, e g., an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry to receive signals and processing circuitry to process the signals and other information. The engines may also be embodied as one application or separate applications. In addition, in some UEs, the functionality described for the processor 205 is split among two or more processors such as a baseband processor and an applications processor. The example embodiments may be implemented in any of these or other configurations of a UE.

[ 0061 ] The memory arrangement 210 may be a hardware component configured to store data related to operations performed by the UE 110. The display device 215 may be a hardware component configured to show data to a user while the EO device 220 may be a hardware component that enables the user to enter inputs. The display device 215 and the EO device 220 may be separate components or integrated together such as a touchscreen.

[ 0062 ] The transceiver 225 may be a hardware component configured to establish a connection with the 5G NR-RAN 120, an LTE-RAN (not pictured), a legacy RAN (not pictured), a WLAN (not pictured), etc. Accordingly, the transceiver 225 may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies). The transceiver 225 includes circuitry configured to transmit and/or receive signals (e.g., control signals, data signals). Such signals may be encoded with information implementing any one of the methods described herein. The processor 205 may be operably coupled to the transceiver 225 and configured to receive from and/or transmit signals to the transceiver 225. The processor 205 may be configured to encode and/or decode signals (e.g., signaling from a base station of a network) for implementing any one of the methods described herein.

[ 0063] Fig. 3 shows an example base station 300 according to various example embodiments. The base station 300 may represent the gNB 120A or the gNB 122 A or any other access node through which the UE 110 may establish a connection and manage network operations.

[ 0064 ] The base station 300 may include a processor 305, a memory arrangement 310, an input/output (I/O) device 315, a transceiver 320, and other components 325. The other components 325 may include, for example, an audio input device, an audio output device, a battery, a data acquisition device, ports to electrically connect the base station 300 to other electronic devices and/or power sources, etc.

[ 0065 ] The processor 305 may be configured to execute a plurality of engines for the UE 110. For example, the engines may include a Dual Steer engine 335 for relaying MADS-PDU information between the UE 110 and the core network 130. Each of these example operations will be described in more detail below. Though engines 335 and 340 are shown as separate engines, in some embodiments, engines 335 and 340 may be combined into a single engine.

[ 0066] The memory arrangement 310 may be a hardware component configured to store data related to operations performed by the base station 300. The VO device 315 may be a hardware component or ports that enable a user to interact with the base station 300.

[ 0067 ] The transceiver 320 may be a hardware component configured to exchange data with the UE 110 and any other UE in the network arrangement 100. The transceiver 320 may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies). The transceiver 320 includes circuitry configured to transmit and/or receive signals (e g., control signals, data signals). Such signals may be encoded with information implementing any one of the methods described herein. The processor 305 may be operably coupled to the transceiver 320 and configured to receive from and/or transmit signals to the transceiver 320. The processor 305 may be configured to encode and/or decode signals (e.g., signaling from a UE) for implementing any one of the methods described herein.

[ 0068 ] As stated above, the example embodiments are related to the aspect of enhancing session management procedures for dual steer capable UEs. This may include initial steering and potential subsequent switching between the different access networks for dual steer UEs. Prior to describing the example embodiments, some terminology related to dual steer UEs will be provided.

[ 0069] Steering describes a process associated with selecting one of the two access networks (e.g., the two 3GPP access networks) on which traffic for a particular service will be handled.

[ 0070 ] Switching describes a process associated with moving the traffic for a service from one of the two access networks to the other one of the two access networks. Examples of different access networks were provided above.

[ 0071 ] The dual steer UE may have the capability and functionality to steer and/or switch user traffic across two accesses based on provided Dual Steer rules, e.g., UE Route Selection Policy (URSP) rules. The UE may use or apply 1) a higher layer functionality, which operates above an internet protocol (LP) layer using Multi-Path TCP (MPTCP); or 2) a lower layer functionality operating below the IP layer using Dual Steer-lower layer (DualSteer-LL). For example, the UE may monitor link quality (e.g., Quality of Service (QoS), Quality of Experience (QoE), round trip time (RTT), etc.) on the two legs of an MADS-PDU session and determine traffic steering and switching decisions based on this monitoring and/or the DualSteer rules.

[ 0072 ] The PCF 135 may provide DualSteer traffic routing rules to the UE 110 via the SMF 132. The SMF 132 may provide N4 interface rules to the UPF 133 dictating how downlink traffic should be routed. Performance Management Function (PMF) messages may be exchanged between the UE 110 and the UPF 133 for RTT measurements over each access type. Thus, dual steering enables intelligently routing device traffic across two simultaneous network connections.

[ 0073 ] Prior to describing the example session management procedures, the following will describe some example registration procedures for a dual steer UE. [ 0074 ] Fig. 4 shows an example registration procedure 400 for a dual steer UE 401 according to various example embodiments. The registration procedure 400 may be performed between a dual steer UE 401 comprising a first UE 402 and a second UE 404 and a first access network 406 and a second access network 408. The first UE 402 and the second UE 404 may be part of a same physical device, e.g., a smartphone, or may be two separate physical devices, e.g., a smartphone and a connected wearable device. As described above, the access networks 406 and 408 may be two 3 GPP access networks. In addition, each access network 406 and 408 has a corresponding AMF with which the dual steer UE 401 will register.

[ 0075 ] In 410, the first UE 402 of the dual steer device 401 sends a registration request to the first access network 406. The registration request includes an indication that the first UE 402 has a dual steer capability, the SUPI of the first UE 402 and an indication that the first UE 402 wants to use this access network as a primary access. The primary access indication indicates to the network that the first UE 402 wants to receive, for example, paging, control messages, etc. using this access. In some example embodiments, the SUCI or the PEI of the first UE 402 may be indicated instead of or in addition to the SUPI. In some example embodiments, the registration request may also include the SUPI, SUCI or PEI of the second UE 404.

[ 0076 ] The AMF of the first access network 406 may perform various operations upon receiving the registration request such as verifying with the UDM function of the network that the first UE 402 is dual steer capable and has a dual steer subscription, creating a context in the network for the first UE 402, etc.

[ 0077 ] In 415, the AMF of the first access network 406 sends a registration accept message to the first UE 402. The registration accept message may include the 5G-GUTI-1 which is the temporary identifier for the first UE 402, an indication that the subscription of the first UE 402 supports dual steer capability and a list of PLMNs available for the dual steer UE 401s.

[ 0078 ] The operation 415 assumes that the registration is successful. In cases where the registration is not successful (e.g., the first UE 402 does not have a dual steer subscription), the AMF of the first access network 406 may, in 420, may send a registration reject message. For the purposes of the example embodiments, it may be considered that the registration procedure is successful.

[ 0079] After the registration of the first UE 402 with the first access network 406 is successful, the dual steer UE 401 may then attempt to register the second UE 404 with the second access network 408. In 425, the second UE 404 of the dual steer UE 401 sends a registration request to the second access network 408. The registration request includes an indication that the second UE 404 has a dual steer capability, the SUPI of the second UE 404, the 5G-GUTI-1 assigned to the first UE 402 and an indication that the second UE 404 wants to use this access network as a secondary access. The secondary access indication indicates to the network that the second UE 404 does not want to receive, for example, paging, mobile terminating (MT) traffic, etc., using this access to conserve UE battery power. Again, in some example embodiments, the SUCI or the PEI of the second UE 404 may be indicated instead of or in addition to the SUPI.

[ 0080 ] The AMF of the second access network 408 may perform various operations upon receiving the registration request. In this case, since the registration request includes the 5G- GUTI-1 assigned to the first UE 402 by the first access network 406, the AMF of the second access network 408 will determine that the second UE 404 is a dual steer UE. The AMF of the second access network 408 may again contact the UDM function of the network to verify that the second UE 404 is dual steer capable and has a dual steer subscription. Based on this information, the UDM will now understand that two access networks 406 and 408 that are being used by the dual steer UE 401, e.g., by keeping the AMF identifications (IDs) in the UDM. The AMF of the second access network 408 may also create a context in the network for the second UE 404.

[ 0081 ] In 430, the AMF of the second access network 408 sends a registration accept message to the second UE 404. The registration accept message may include the 5G-GUTI-2 which is the temporary identifier for the second UE 404, an indication that the subscription of the first UE 402 supports dual steer capability and a list of PLMNs available for dual steer UE 401. [ 0082 ] The operation 430 assumes that the registration is successful. In cases where the registration is not successful, the AMF of the second access network 408 may, in 435, send a registration reject message. For the purposes of the example embodiments, it may be considered that the registration procedure is successful.

[ 0083 ] Thus, at this point, it may be considered that the registration of the dual steer UE 401 with the two access networks 406 and 408 is successful, e g., the registration reject messages of 420 and 435 were not performed. At a later time, in 440, the access networks 406 and 408 may receive an incoming MT call for the dual steer UE 401. As described above, in this example, the dual steer UE 401 has registered to receive primary access (e.g., paging) using the first UE 402 via the first access network 406. Thus, the second access network 408 may ignore the MT call, while the first access network 406 may send, in 445, an AMF paging message to the first UE 402 of the dual steer UE 401. This is just one example operation that mat be performed when the dual steer UE 401 is currently registered with the two access networks 406 and 408.

[ 0084 ] In addition, at any time, the UE 402 or the UE 404 may send a deregistration request, 450 and 455 respectively, to deregister from the access network.

[ 0085 ] In other example embodiments, instead of the registration request including an indication of primary or secondary access, the registration request may include a paging restriction. For example, the paging restriction may indicate that the UE will accept paging or the UE will not accept paging. The result may be similar to the above described example without any indication as to whether a particular access network is a primary access network or a secondary access network.

[ 0086 ] The following will provide examples of session management procedures that may be used for dual steer UEs.

[ 0087 ] Fig. 5 shows an example session management procedure 500 for a dual steer UE 501 according to various example embodiments. Similar to the registration procedure of Fig. 4, the session management procedure 500 is performed between the dual steer UE 501 comprising the first UE 502 and the second UE 504 and a first access network 506 and a second access network 508.

[ 0088 ] In 510, the dual steer UE 501 performs a registration procedure with the first access network 506 and a second access network 508 such that the first UE 502 is registered with the first access network 506 and the second UE 504 is registered with the second access network 508. The registration procedure may be, for example, the registration procedure 400 described above or any other applicable registration procedure for dual steer UEs.

[ 0089] In 515, the first UE 502 of the dual steer UE 501 sends a PDU session establishment request to the first access network 506. The PDU session establishment request may include a dual steer capability of the first UE 502, e.g. a DualSteer-ST Information Element (IE) of a 5G Session Management (5GSM) Capability IE. An example of the 5GSM Capability IE is provided below with reference to Fig. 22.

[ 0090 ] The PDU session establishment request may also include an indication that the request is an initial request for the PDU session and that an MADS-PDU session is being requested. The MADS-PDU Session was described above, e g., there are two legs to the PDU session, one for each access network 506 and 508. In some example embodiments, instead of an MADS-PDU session, two separate PDU sessions may be established, e.g., one for each 3GPP access network.

[ 0091 ] When the AMF of the first access network 506 receives the PDU session establishment request, the AMF may perform certain operations. For example, the AMF, based on the first UE identification information, may determine from the UE context with the first access network 506 that the first UE 502 is a dual steer UE and is attempting to establish a dual steer PDU session. The AMF may select an SMF that is dual steer capable and may pass the dual steer capabilities of the first UE 502, the UE ID and other information to the SMF. The SMF then selects a UPF that has a dual steer capability and the PDU session is established. In some cases the network may select a UPF such that the UPF acts as a common PDU Session Anchor for the Dual Steer device. [ 0092 ] If the above operations are successful, in 520, the AMF of the first access network 506 sends a PDU Session Establishment Accept message to the first UE 502. The PDU Session Establishment Accept message may include a PDU session ID for this PDU session, a dual steer container that may include, for example, rules and/or policies for the PDU session, and a selected PDU session type. The PDU session type indicate the type of PDU session, e.g., dual steer PDU session or single PDU session. That is, if the AMF determines that the UE does not support dual steer capabilities, the network may just establish a single PDU session in response to the PDU session establishment request.

[ 0093] If there was an error establishing the PDU session, in 525, the AMF of the first access network 506 may send a PDU Session Establishment Reject message indicating a reason, e.g., 5GSM cause code, that the PDU session was not established. For the purposes of the example embodiments, it may be considered that the dual steer PDU session establishment was successful.

[ 0094 ] In 530, the second UE 504 of the dual steer UE 501 sends a PDU session establishment request to the second access network 508 to establish the second leg of the dual steer PDU session. Similar to the PDU session establishment request described above, this request may also include the dual steer capabilities of the second UE 504 (e.g. DualSteer-ST IE), an indication that the request is an initial request for the PDU session and that an MADS-PDU session is being requested. The PDU session establishment request may also include the PDU Session ID that was returned to the first UE 502 in 520.

[ 0095 ] When the AMF of the second access network 508 receives the PDU session establishment request, the AMF may perform certain operations. The indication of the PDU Session ID in the PDU session establishment request indicates to the AMF of the second access network 508 that this is a request for a second leg of the dual steer PDU session. The AMF of the second access network 508 may query the UDM using PDU Session ID whether a first PDU session has already been established for this DualSteer device. If so, then the AMF may query the UDM for the identification of the SMF selected for the first access network 506 to host the dual steer PDU session. The selected SMF then selects the same UPF (which acts as common PDU Session Anchor (PSA) that has the dual steer capability and the second leg of the PDU session is established.

[ 0096] If the above operations are successful, in 535, the AMF of the second access network 508 sends a PDU Session Establishment Accept message to the second UE 504. The PDU Session Establishment Accept message may include the PDU session ID for this PDU session, a dual steer container that may include, for example, rules and/or policies for the PDU session, and a selected PDU session type as previously described above.

[ 0097 ] If there was an error establishing the PDU session, in 540, the AMF of the second access network 508 may send a PDU Session Establishment Reject message indicating a reason, e.g., 5GSM cause code, that the PDU session was not established. For the purposes of the example embodiments, it may be considered that the dual steer PDU session establishment was successful.

[ 0098 ] In the above example, the PDU Session ID for the first leg and the second leg are the same PDU Session ID and this links the two legs of the dual steer PDU session, e.g., the network will use the same SMF and UPF for the two legs. In some example embodiments, a different identifier may be used to link the two legs of the dual steer PDU Session. For example, the network may generate some other type of identifier such as a correlation identifier or linkage identifier to link the two legs. In any case, this identifier may be returned to the first UE 502 in the PDU Session Establishment Accept message and the second UE 504 may include the identifier in the PDU Session Establishment Request. Thus, the use of the PDU Session ID is only an example and there may be other manners of linking the two legs of the dual steer PDU session.

[ 0099] Once the dual steer PDU session is established, the dual steer PDU session may also be modified for any number of reasons to change the properties of the PDU session. For example, the first UE 502 may request a change to the Quality of Service (QoS) of the current PDU session. This is only an example and the example embodiments may be applied to a modification request for any reason. In the example of Fig. 5, the first UE 502 makes the modification request to the network but the second UE 504 may also make a modification request.

[ 0100 ] In 545, the first UE 502 sends a PDU Session Modification Request to the first access network 506. The PDU Session Modification Request may include the dual steer capabilities, an indication that the request is for an existing PDU session and that the request is for an MADS-PDU session.

[ 0101 ] If the network can accommodate the modification request, in 550, the AMF of the first access network 506 sends a PDU Session Establishment Command to the first UE 502 indicating the changes to the PDU session. The PDU Session Establishment Command may include the PDU session ID for this PDU session, a dual steer container that may include, for example, rules and/or policies for the PDU session, and a selected PDU session type as previously described above.

[ 0102 ] If there was an error modifying the PDU session, in 555, the AMF of the first access network 506 may send a PDU Session Modification Reject message indicating a reason, e g., 5GSM cause code, that the PDU session was not modified. For the purposes of the example embodiments, it may be considered that the dual steer PDU session modification was successful.

[ 0103] In some example embodiments, the dual steer UE 501 may also enable user plane resources for preferred access for transmitting traffic for a particular service. Some examples of preferred access networks were described above. For example, when the dual steer PDU session is started, neither the first leg nor the second leg may be indicated as the preferred access. Based on link monitoring, the dual steer UE 501 may determine that one of the UEs 502 and 504 should be the preferred access for the service being executed. In the example of Fig. 5, the first UE 502 makes the request for user plane resources for first access network which is the preferred access. While the below example describes a request for establishing user plane resources for the preferred access, the request may also be for establishing this access as the primary access. The request for primary access indicates to the network that all paging and MT terminated messages should be routed over the access network that is indicated as the primary access.

[ 0104 ] In 560, the first UE 502 sends a Registration Request to the first access network 506. The Registration Request may include the dual steer capabilities, the SUPI of the first UE 502 and an indication of a request for primary access.

[ 0105 ] In 565, the AMF of the first access network 506 may send a Registration Accept message to the first UE 502 that includes the 5G-GUTI-1 for the first UE 502, an indication that the UE subscription supports the dual steer capability and a list of PLMNs that may be used by the first UE 502 for dual steer. Thus, at the completion of operation 565, the first UE 502 and the first access network 506 may be used as a primary access via the dual steer PDU session.

[ 0106] In some example embodiments, the PDU session for an access network may be released and a new PDU session may be established using a different access.

[ 0107 ] In 570, the first UE 502 sends a PDU Session Release Request to the first access network 506 to release the first access of the dual steer PDU session. In 575, the first access network 506 sends a PDU Session Release Command to release the first access of current dual steer PDU session. Thus, at this point, the second leg of the dual steer PDU session is the only active leg. Thus, the traffic for the session may be switched to the second leg. The traffic switching across PDU sessions may not change the primary/secondary access as the concept of a primary or secondary access network is independent of a service, but specifies over which access network the UE is to receive paging and mobile-terminated control messages from the network to optimize UE battery power. From a Dual Steer perspective, an access network may be preferred based on link conditions and thus traffic may be steered or switched to that access network and the corresponding PDU session.

[ 0108 ] The preferred access network may not necessarily be the primary access network as well. An access network is preferred to carry a certain type of traffic, whereas primary access network is better suited for paging and MT calls, etc. in that sense terrestrial networks are better suited to be primary access networks as compared to non-terrestrial networks].

[ 0109] At a subsequent time, the first UE 502 may establish a new dual steer PDU session with the access network. This process is shown in Fig. 5 as operations 580-590. The operations 580-590 are similar to the operations 515-525 described above for establishing a dual steer PDU session and will not be described again.

[ 0110 ] In some example embodiments, instead of using the Registration Request to enable user plane resources for preferred access, a Service Request may be used. Some examples of preferred access were described above. Again, in the example of Fig. 5, the first UE 502 makes the request for user plane resources but the second UE 504 may also make the request.

[ 0111 ] In 593, the first UE 502 sends a Service Request to the first access network 506. The Service Request may include the dual steer capabilities, the SUPI of the first UE 502 and an indication of a request for the first access network to also be the primary access.

[ 0112 ] In 597, the AMF of the first access network 506 may send a Service Accept message to the first UE 502 that includes the 5G-GUTI-1 for the first UE 502, an indication that the UE subscription supports the dual steer capability and a list of PLMNs that may be used by the first UE 502 for dual steer. Thus, at the completion of operation 597, the first UE 502 and the first access network 506 may be used as a primary access via the dual steer PDU session.

[ 0113] Fig. 6 shows a second example session management procedure 600 for a dual steer UE 601 according to various example embodiments. The session management procedure 600 is performed between the dual steer UE 601 comprising the first UE 602 and the second UE 604 and a first access network 606 and a second access network 608. The operations 610-655 are similar to the operations 510-555 described above with reference to Fig. 5 and therefore will not be described again. [ 0114 ] In the example of Fig. 6, instead of using a release request/command as shown in Fig. 5 to switch the access from one leg of the dual steer PDU session to the other leg, a suspend request on one leg of the dual steer PDU session may be used. In this manner, the access network does not need to release the context associated with the suspended leg of the PDU session such that the suspended leg may be resumed at a later time without having to establish a new PDU session. These example embodiments are described below.

[ 0115 ] In 660, the first UE 602 sends a PDU Session Suspend Request to the AMF of the first access network 606. As stated above, this request may be associated with a determination by the dual steer UE 601 that the PDU session leg between the first UE 602 and the first access network 606 is not the optimal leg to be used for traffic for the service (e.g., based on link monitoring such as described above). To switch the traffic to the other leg of the dual steer PDU session, the dual steer UE 601 requests that the underperforming leg of the PDU session be suspended so that the traffic is routed through the other leg.

[ 0116] In 665, the AMF of the first access network 606 sends a PDU Session Suspend Accept message indicating to the first UE 602 that this leg of the dual steer PDU session is suspended. Thus, the traffic for the service of the dual steer PDU session will be exchanged using the other leg, e g., the non-suspended leg of the dual steer PDU session.

[ 0117 ] At a later time, the dual steer UE 601 may want to resume the leg of the dual steer PDU session that was suspended. For example, the link monitoring may indicate that this leg is now the optimal leg for traffic. Thus, in 670, the first UE 602 sends a PDU Session Resume Request to the AMF of the first access network 606. Because the leg of the PDU session associated with the first UE 602 was only suspended and not released, the first access network may still include the context of the PDU session for the first UE 602. Thus, the AMF of the first access network 606 may resume the leg of the dual steer PDU session associated with the first UE 602 and send a PDU Session Resume Accept message to the first UE 602. Because this leg of the dual steer PDU session is indicated as the preferred access, the traffic for the service may then again be switched to this leg of the PDU session. [ 0118 ] Similar to the operations described with respect to Fig. 5, in some example embodiments, a Service Request may be used to enable user plane resources for preferred access. Again, in the example of Fig. 6, the first UE 602 makes the request for user plane resources but the second UE 604 may also make the request.

[ 0119] In 680, the first UE 602 sends a Service Request to the first access network 606. The Service Request may include the dual steer capabilities, the SUPI of the first UE 602 and an indication of a request for the first access network to also be the primary access.

[ 0120 ] In 685, the AMF of the first access network 606 may send a Service Accept message to the first UE 702 that includes the 5G-GUTI-1 for the first UE 602, an indication that the UE subscription supports the dual steer capability and a list of PLMNs that may be used by the first UE 702 for dual steer. Thus, at the completion of operation 685, the first UE 602 and the first access network 606 may be used as a primary access via the dual steer PDU session.

[ 0121 ] Fig. 7 shows an end-to-end call flow 700 for session management procedures for a home routed MADS-PDU session according to various example embodiments. The call flow 700 includes a dual steer UE 701 comprising a first UE 702 with a first SUPI-1 and a second UE 704 with a second SUPI-2. The call flow 700 further includes a first access network 710 that includes an AMF 712, an SMF 714 and a UPF 716. The call flow 700 also includes a second access network 720 that includes an AMF 722, an SMF 724 and a UPF 726.

[ 0122 ] In 730, the first UE 702 performs a registration procedure with the AMF 712 using the SUPI-1, e.g., the registration procedure 400 described above. The first UE 702 may indicate whether the first UE 702 supports a dual steer capability during the registration procedure. The AMF 712 may indicate to the UE 702 that the network supports the dual steer capability during the registration procedure (e.g., in a Registration Accept message).

[ 0123] Similarly, in 735, the second UE 704 performs a registration procedure with the AMF 722 using the SUPI-2, e.g., the registration procedure 400 described above. The second UE 704 may indicate whether the second UE 704 supports a dual steer capability during the registration procedure. The AMF 722 may indicate to the UE 704 that the network supports the dual steer capability during the registration procedure (e.g., in a Registration Accept message).

[ 0124 ] If the AMF 712 indicates that dual steer is not supported by the AMF 712, then the UE 702 may not initiate a PDU session activation/modification for dual steer (until indicated by the AMF 712 in a Registration Accept or modified in a Configuration Update Command Procedure based on a subscription change indicated by the UDM) or a registration procedure performed on a new tracking area (TA) or PLMN. The UE 702 may request a PDU session activation including a same Single - Network Slice Selection Assistance Information (S-NSSAI) over both accesses only if the S-NSSAI is in the allowed NSSAI list. Similar operations and restrictions may be applied when the AMF 722 indicates that dual steer is not supported.

[ 0125 ] For the UE 701 configured to run in dual steer mode, if during SUPI-2 registration procedure, dual steer registration fails and no other PLMN can provide dual steer service, then the UE 701 may periodically searching for PLMNs (e.g., based on 3GPP Technical Specification (TS) 23.122 based on the access type) which can provide dual steer service. In this state, the UE 701 may not attempt to register in normal mode. For example, in NTN access, the UE search may rely on the satellite almanac information for searching and camping.

[ 0126] In 740, the first UE 702 sends a PDU Session Establishment Request to the SMF 714 via the AMF 712. As described above, the PDU Session Establishment Request may include the DualSteer-ST IE and a request type indicating a dual steer type of PDU session activation. The UE 702 SUPI-1 may include the request type in an uplink (UL) non-access stratum (NAS) transport message. The request type may indicate a request to establish either an MADS-PDU session or a single leg PDU session.

[ 0127 ] In 745, the AMF 712 updates the UDM as to the selected SMF 714 for a dual steer PDU session. The UDM may maintain a mapping table that maps active SMF IDs to SUPIs. This operation is used for dual steer functionality to help the AMF in SMF selection. The concept is to contact the same home SMF (H-SMF) when activating the PDU session on the second leg using SUPI-2. Thus, as stated above, the AMF 712 updates the home UDM (H-UDM) about the SMF ID of the SMF 714 selected for activating the PDU session. This information may be used later when the second UE 704 initiates PDU session activation on the second leg of the MADS-PDU session.

[ 0128 ] In 750, the SMF 714 selects the UPF(s) (e.g., UPF 716) and provides the IP address for the PDU session to the first UE 702. The AMF 712 and/or the SMF 714 may decide if the PDU session needs to be a local breakout or home routed. The Session and Service Continuity (SSC) mode may be decided based on configuration or the SSC mode provided by the UE 702 in the Session Establishment Request.

[ 0129] In 755, the SMF 714 queries the UPF 716 to determine if the UE 702 is allowed to have an MADS-PDU session based on operator policy and subscription data. If the UE 702 indicates “DualSteer-LL Capability” then the SMF 714 derives the steering and switching rules. The SMF 714 may also provide measurement assistance information for the UE 702. The SMF 714 may indicate to the UPF 716 to measure performance measurements. The SMF 714 may also provide the MPTCP proxy information and the "link-specific multipath" addresses/prefixes of the UE 702 in the PDU Session Establishment Accept message.

[ 0130 ] In 760, the PDU Session is created on the second leg (e g., the UE 704 with the access network 720) by selecting the H-SMF 724 (which is the same SMF as 712) derived from the UDM that maintains the mapping table of SMF IDs with the SUPIs (e.g., the SUPI-1 mapped to the SMF ID of SMF 714). Thus, at the completion of 760, the two legs of the MADS-PDU session are established.

[ 0131 ] Fig. 8 shows an end-to-end call flow 800 for session management procedures for handoff to a second leg of a home routed MADS-PDU session according to various example embodiments. The call flow 800 includes a dual steer UE 801 comprising a first UE 802 with a first SUPI-1 and a second UE 804 with a second SUPI-2. The call flow 800 further includes a first access network 810 that includes an AMF 812, an SMF 814 and a UPF 816. The call flow 800 also includes a second access network 820 that includes an AMF 822, an SMF 824 and a UPF 826. [ 0132 ] The operations 830-855 are similar to the operations 730-755 described above with reference to Fig. 7 and will not be described again.

[ 0133] In 860, the UE 802 loses network coverage but the UE 804 remains in network coverage, e.g., the dual steer UE 801 wants to handover to the second leg of the MADS-PDU Session. The example of losing coverage is only an example, there may be other reasons why the dual steer UE 801 may want to switch to the second leg of the MADS-PDU session.

[ 0134 ] In 865, the UE 806 sends a PDU Session Establishment Request with a reqType “Existing PDU Session” for handover of the PDU session established on access network 710 to the access network 720 (e.g., the second leg of the MADS-PDU session).

[ 0135 ] In 870, the PDU Session is created on leg 2 by selecting the H-SMF derived from UDM that maintains a mapping table of SMF ID with the SUPIs, e.g., the SMF ID of SMF 814.

[ 0136] Fig. 9 shows an end-to-end call flow 900 for session management procedures for a local breakout MADS-PDU session according to various example embodiments. The call flow 900 includes a dual steer UE 901 comprising a first UE 902 with a first SUPI-1 and a second UE 904 with a second SUPI-2. The call flow 900 further includes an AMF 912, an SMF 914, a UPF 916 and a H-UDM 918.

[ 0137 ] The operations 930-955 are similar to the operations 730-755 described above with reference to Fig. 7 and will not be described again. However, in this example, the UPF selection 945 may be performed prior to the AMF 912 updating the H-UDM 918 about the SMF ID. In 960, the data radio bearers (DRBs) are established for the UE 902.

[ 0138 ] In 970, the UE 902 detects loss of coverage or packet measurement characteristics (e g., RTT, packet loss, latency, etc.) on the UE 902 link that indicates the connection is not sufficient for the ongoing service. [ 0139] In 975, the dual steer UE 901 determines that transferring the DRBs to UE 904 is to be performed. Thus, the UE 904 initiates a PDU Session Establishment Request for SUPI-2 indicating the request is for dual steer.

[ 0140 ] In 980, the AMF 912 fetches from the H-UDM 918 the SMF ID to be selected as it is a Dual Steer type of PDU Session, e.g., the SMF ID of the SMF 914.

[ 0141 ] In 985, the UE 904 sends a PDU Session Establishment Request that includes same PDU Session ID (received on SUPI1), the DualSteer-ST IE and includes a request type indicating dual steer type of PDU session activation. The UE 904 includes request type in a UL NAS Transport message. The request type may indicate a request to establish an MADS PDU session. The UE 904 may also indicate “DualSteer-EL Capability” or the MPTCP functionality or both.

[ 0142 ] In 990, the SMF 914 establishes new N9, N3 tunnels and updates the dual steer rules, if needed, in the DualSteer Container IE in the PDU Session Establishment Accept message. In 995, the DRBs are established for the UE 904.

[ 0143] The following provides some example network architectures to implement the dual steer capability for home routed architectures and local breakout configurations.

[ 0144 ] Fig. 10 shows a home routed architecture diagram 1000 for dual steer support for a PDU session handover according to various example embodiments. To support PDU session handover from one access network to another in a home routed configuration, the UE (SUP 12) provides the 5G-GUTI-1 received by the UE (SUPI1) during registration procedure and sends a Service Request (or a new NAS message) for AMF-1 via AMF-2. AMF-1 decrypts and successfully checks the integrity protection on the Service Request message (or new NAS message) sent by the UE (SUPI-1). The AMF-1 then sends the SMF-1 and all other PDU session details (UE SUPI1 context) on leg-1 to the AMF-2. The AMF-2 may then use the context to select the SMF and subsequently the H-SMF and accordingly the H-UPF for continuing the PDU session using the “Existing PDU session” type. [ 0145 ] Fig. 11 shows an alternative home routed architecture diagram 1100 for dual steer support for a PDU session handover according to various example embodiments. To support PDU Session handover from one access network to another in a local breakout configuration, the AMF-2, during activation of any new PDU session on leg 1, will update the UDM about the SMF ID selected for the SMF PDU session creation. Any PDU session release may cause the UDM to be updated for either of the SMFs. Similarly in leg-2, the AMF on detecting transfer of PDU session from leg-1 (type of PDU session is “Existing PDU session” then it fetches from the UDM, information of the SMF to be selected) in this case the H-SMF.

[ 0146] Fig. 12 shows a home routed architecture diagram 1200 for dual steer support for a MADS-PDU session handover according to various example embodiments. To support MADS-PDU Session for dual steer from one access network to another in a local breakout configuration, the UE (SUPI2) provides the 5G-GUTI-1 (received on UE(SUPIl) during the registration procedure) and sends a Service Request message (or a new NAS message) for the AMF-1 via the AMF-2. The AMF-1 decrypts and successfully checks the integrity protection on the Service Request message (or a new NAS message) sent by the UE(SUPI-l). Then, the AMF- 1 sends the SMF-1 ID and all other PDU session details on leg-1 to the AMF-2. The AMF-2 selects the SMF and accordingly the UPF is selected for continuing the PDU session using the “Existing PDU session” type.

[ 0147 ] Fig. 13 shows an alternative home routed architecture diagram 1300 for dual steer support for an MADS-PDU session handover according to various example embodiments. To support an MADS-PDU Session across two access networks in a home routed configuration, the AMF-2, during activation of any new PDU session on leg 1, updates the UDM about the SMF ID selected for SMF PDU session creation. The PDU session may cause the UDM to be updated for either of the SMFs.

[ 0148 ] Fig. 14 shows a local breakout architecture diagram 1400 for dual steer support for an MADS-PDU session according to various example embodiments. To support MADS-PDU Session for dual steer from one access network to another in a local breakout configuration, the UE (SUPI2) provides the 5G-GUTI-1 (received by the UE(SUPIl) during the registration procedure) and sends a Service Request message (or a new NAS message) for the AMF-1 via the AMF-2. The AMF-1 decrypts and successfully checks the integrity protection on the Service Request message (or a new NAS message) sent by the UE(SUPI-l). Then, the AMF-1 sends the SMF-1 ID and all other PDU session details on leg-1 to the AMF-2. The AMF-2 may select the SMF and accordingly UPF is selected for continuing the PDU session using the “Existing PDU session” type.

[ 0149] Fig. 15 shows an alternative local breakout architecture diagram 1500 for dual steer support for an MADS-PDU session according to various example embodiments. In this example, the UE is camped on 2 access networks (e.g., NTN & TN) using the same AMF and different UPFs or the same UPF in the home network or both legs in same VPLMN in the local breakout configuration for the MADS-PDU session. The operations in this architecture are similar to those describe with respect to the operations for the architecture 1400 of Fig. 14.

[ 0150 ] Fig. 16 shows a local breakout architecture diagram 1600 for dual steer support for an MADS-PDU session handover according to various example embodiments. To support PDU session handover from one access network to another in the local breakout configuration, the UE(SUPI2) provides the 5G-GUTI-1 (received on UE(SUPIl) during the registration procedure) and sends a Service Request message (or a new NAS message) for the AMF-1 via the AMF-2. The AMF-1 decrypts and successfully checks the integrity protection on the Service Request message (or new NAS message) sent by the UE(SUPI-l). Then, the AMF-1 will send the SMF-1 and all other PDU session details (UE SUPI1 context) on leg-1 to the AMF-2. The AMF-2 may use the context to select the SMF and accordingly the UPF for continuing the PDU session using the “Existing PDU session” type.

[ 0151 ] Fig. 17 shows an alternative local breakout architecture diagram 1700 for dual steer support for an MADS-PDU session handover according to various example embodiments. To support PDU session handover from one access network to another in the local breakout configuration, the AMF-2, during activation of any new PDU session on leg 1, may update the UDM about the SMF ID selected for the SMF PDU session creation. Similarly, in leg-2, the AMF on detecting transfer of the PDU session from leg-1 (type of PDU session is “Existing PDU session” then it fetches from the UDM, information of the SMF to be selected) in this case SMF-1.

[ 0152 ] The following provides some example layer diagrams to implement the dual steer capability for a dual steer UE.

[ 0153] Fig. 18 shows an example layer diagram 1800 for a dual steer UE having a single subscriber identity module (SIM) with a non-access stratum (NAS) layer instantiated according to various example embodiments. In this example, a common Universal SIM (USIM) has separate elementary files (EFs) to store NAS contexts for each instance of NAS- 1 and NAS-2. Based on service loss or service recovery on one of the legs, the other NAS entity may initiaten a search using the same AS layer.

[ 0154 ] Fig. 19 shows an example layer diagram 1900 for a dual steer UE having a single SIM with a NAS layer, an access stratum (AS) layer and layer 2 instantiated according to various example embodiments. In this example, a common USIM havs separate EFs to store NAS contexts for each instance of NAS- 1 and NAS-2 and the AS and radio link control (RLC) layers are also instantiated. Based on service loss or service recovery on one of the legs, the other NAS and AS entities utilize the same Physical Layer (PHY) and RF for search.

[ 0155 ] Fig. 20 shows an example layer diagram 2000 for a dual steer UE having dual SIM with a NAS layer, an access stratum (AS) layer and layer 2 instantiated according to various example embodiments. In this example, separate USIMs store the NAS contexts for each NAS- 1/AS-l and NAS-2/AS-2 instance. Both NAS instances may exchange messages to each other. Based on service loss or service recovery on one of the legs, the other NAS and AS entities utilize same PHY and RF for search.

[ 0156] Fig. 21 shows an example layer diagram 2100 for a dual steer UE having two separate physical UEs according to various example embodiments. In this example, separate USIM on the separate UEs store the respective NAS and AS contexts. Both NAS instances may exchange messages to each other. Based on service loss or service recovery on one of the legs, the other NAS and AS entities utilize same PHY and RF for search.

[ 0157 ] The following provides some example session management messages that may be exchanged between a dual steer UE and an access network during dual steer operations.

[ 0158 ] Fig. 22 shows an example of a 5G Session Management (5GSM) Capability IE 2200 according to various example embodiments. The DualSteer-ST IE of the 5GSM Capability IE 2200 may indicate the dual steer functionalities and steering modes supported by the dual steer UE, e.g., as sent in the PDU Session Establishment Request 515. These may include, but are not limited to, dual steer not supported, dual steer Low-Layer (Dual Steer LL) functionality with any steering mode allowed for Dual Steer-LL supported, MPTCP functionality with any steering mode and Dual Steer-LL functionality with only active-standby steering mode supported, MPTCP functionality with any steering mode and Dual Steer-LL functionality with any steering mode allowed for DualSteer-LL supported, Multipath Quick UDP Internet Connection (MPQU1C) functionality with any steering mode and DualSteer-LL functionality with only active- standby steering mode supported, MPQUIC functionality with any steering mode and Dual Steer-LL functionality with any steering mode allowed for Dual Steer-LL supported, MPTCP functionality with any steering mode, MPQUIC functionality with any steering mode and DualSteer-LL functionality with only active- standby steering mode supported, MPTCP functionality with any steering mode, MPQUIC functionality with any steering mode and DualSteer-LL functionality with any steering mode allowed for DualSteer-LL supported. These are only examples of supported dual steer functionalities and steering modes.

[ 0159] As stated above, the information received by the dual steer UEs when receiving messages from the access network related to the dual steer PDU session (e.g., the PDU Session Establishment Accept message in 525) may include a dual steer container that includes various information related to the dual steer PDU session. Figs. 23A-C show an example of a dual steer container according to various example embodiments. [ 0160 ] Fig. 23 A shows an example of a dual steer container information element 2300 including various information related to the dual steer PDU session. Fig. 23B shows an example of dual steer container contents 2310 included in the dual steer IE 2300. Fig. 23C shows an example of dual steer parameters 2320 included in the dual steer container contents 2310. This is only an example of information that may be included in the dual steer container and it may include additional information.

[ 0161 ] The dual steer container IE 2300 transfer parameters associated with dual steer functionality. In some example embodiments, the dual steer container IE 2300 is a type 6 IE with a minimum length of 3 octets and a maximum length of 65538 octets. This is only an example of a dual steer IE. The dual steer parameters 2320 are the contents of the dual steer container and indicate the parameters associated with the dual steer functionality (e.g., dual steer rules). The dual steer container contents 2310 may include one or more dual steer parameters.

[ 0162 ] Fig. 24 shows an example of a dual steer IE 2400 that indicates dual steer specific information from a UE to the network or from the network to the UE according to various example embodiments. In some examples, the dual steer IE 2400 is a type 4 information element with a length of 3 octets but is not limited to being this type or length of IE.

[ 0163] A first example field of the dual steer IE 2400 is a 3GPP access primary access type (Primary Access) (e.g., octet 3, bit 1). If this bit is set to 0, 3GPP access used in dual steer is not primary access. If this bit is set to 1, 3GPP access used in dual steer is primary access.

[ 0164 ] A second example field of the dual steer IE 2400 is a 3GPP access secondary access type (Secondary Access) (e.g., octet 3, bit 2). If this bit is set to 0, 3GPP access used in dual steer is not secondary access. If this bit is set to 1, 3GPP access used in dual steer is secondary access.

[ 0165 ] A third example field of the dual steer IE 2400 is a Dual Steer Registration (DSR) included in direction from the network to the UE only (e.g., octet 3, bit 3). If this bit is set to 0, Dual Steer Registration is not enabled. If this bit is set to 1, Dual Steer Registration is enabled. [ 0166] A fourth example field of the dual steer IE 2400 is a single leg PDU session a DualSteer PDU (DSP) (e.g., octet 3, bit 4). If this bit is set to 0, the PDU session is not Dual Steer PDU. If this bit is set to 1, the PDU session is Dual Steer PDU.

[ 0167 ] Fig. 25 shows an example of a PDU Session Establishment Request 2500 sent by a UE to the network to initiate establishment of a PDU session according to various example embodiments. This request may be sent by the UE to the network, e.g., operation 515 of Fig. 5. For the purposes of this description, only those fields related to the dual steer functionality are described.

[ 0168 ] A first field may be a 5GSM capability IE that indicates if the UE supports dual steer functionality and includes the dual steer steering modes. A second field may be a dual steer field that indicates the UE supports dual steer functionality and wants to establish a leg of PDU session that is subject to dual steer functionality. A third field may be a dual steer PDU session ID that indicates the UE supports dual steer functionality and wants to establish a second leg of PDU session that is subject to dual steer functionality. This IE indicates the PDU session ID of first leg of PDU session already created earlier.

[ 0169] Fig. 26 shows an example of a PDU Session Establishment Accept message 2600 sent by the network to a UE to indicate successful establishment of a PDU session according to various example embodiments. This request may be sent by the network to the UE, e.g., operation 520 of Fig. 5. For the purposes of this description, only those fields related to the dual steer functionality are described.

[ 0170 ] A first field may be the dual steer container described above with reference to Figs 23A-C. The network may include this information element if the network establishes the PDU session as requested by the UE for session management.

[ 0171 ] Fig. 27 shows an example of a PDU Session Establishment Reject message 2700 sent by the network to a UE to indicate unsuccessful establishment of a PDU session according to various example embodiments. This request may be sent by the network to the UE, e.g., operation 525 of Fig. 5. For the purposes of this description, only those fields related to the dual steer functionality are described.

[ 0172 ] A first field may be a 5GSM cause field indicating a reason (cause) for the dual steer UE not being able to establish a PDU session for dual steer switching or steering of traffic.

[ 0173] Fig. 28 shows an example of a PDU Session Modification Request 2800 sent by the UE to request a modification of a PDU session according to various example embodiments. This request may be sent by the UE to the network, e.g., operation 545 of Fig. 5. For the purposes of this description, only those fields related to the dual steer functionality are described.

[ 0174 ] A first field may be a 5GSM capability field indicating if the UE supports dual steer functionality and includes the dual steer steering modes if the UE wishes to modify them. A second field may be a dual steer field that indicates the UE supports dual steer functionality and wants to modify a leg of PDU session that is subject to the dual steer functionality.

[ 0175 ] Fig. 29 shows an example of a PDU Session Modification Command message 2900 sent by the network to the UE indicating a modification of a PDU session according to various example embodiments. This request may be sent by the network to the UE, e.g., operation 550 of Fig. 5. For the purposes of this description, only those fields related to the dual steer functionality are described.

[ 0176] A first field may be the dual steer container described above with reference to Figs 23A-C. The network may include this information element if the network establishes the PDU session as requested by the UE for session management.

[ 0177 ] Fig. 30 shows an example of a PDU Session Release Request 3000 sent by the UE to the network to request a release of a PDU session according to various example embodiments. This request may be sent by the UE to the network, e.g., operation 570 of Fig. 5. For the purposes of this description, only those fields related to the dual steer functionality are described. [ 0178 ] A first field may be a dual steer field that indicates the dual steer UE wants to release a leg of PDU session that is subject to dual steer functionality. This IE indicates which access is being released (primary or secondary) and whether the session supports dual steer functionality.

[ 0179] Fig. 31 shows an example of a PDU Session Release Command 3100 sent by the network to the UE to indicate a release of a PDU session according to various example embodiments. This request may be sent by the network to the UE, e.g., operation 575 of Fig. 5. For the purposes of this description, only those fields related to the dual steer functionality are described.

[ 0180 ] A first field may be a dual steer field that indicates the dual steer PDU session has been released.

Examples

[ 0181 ] In a first example, a method, comprising generating, for transmission to a first access network, a first request message to establish a first Protocol Data Unit (PDU) session with the first access network, wherein the first request message comprises an indication that a dual steer functionality is supported, processing, based on signaling received from the first access network, a first accept message indicating the first PDU session is established with the first access network, wherein the first accept message further comprises a PDU session identification (ID) for the first PDU session, generating, for transmission to a second access network, a second request message to establish a second PDU session with the second access network, wherein the second request message comprises an indication that the dual steer functionality is supported and the PDU session ID for the first PDU session and processing, based on signaling received from the second access network, a second accept message indicating the second PDU session is established with the second access network, wherein the first PDU session and the second PDU session are associated PDU sessions of the dual steer functionality. [ 0182 ] In a second example, the method of the first example, wherein the first request message further comprises an indication that a request type of the first request message is an initial request.

[ 0183] In a third example, the method of the second example, wherein the second request message further comprises an indication that a request type of the second request message is an initial request.

[ 0184 ] In a fourth example, the method of the first example, wherein the first request message further comprises an indication that the first PDU session is a Multi-Access DualSteer PDU (MADS-PDU) session and the second request message further comprises an indication that the second PDU session is the MADS-PDU session.

[ 0185 ] In a fifth example, the method of the first example, wherein the first PDU session is a separate PDU session from the second PDU session.

[ 0186] In a sixth example, the method of the first example, wherein the first accept message further comprises a dual steer container comprising information related to the dual steer functionality.

[ 0187 ] In a seventh example, the method of the sixth example, wherein the information related to the dual steer functionality comprises UE Route Selection Policy (URSP) rules related to selecting the first access network or the second access network to exchange traffic for a service being executed and parameters and parameter values associated with the URSP rules.

[ 0188 ] In an eighth example, the method of the first example, further comprising generating, for transmission to the first access network, a modification request to modify the first PDU session with the first access network, wherein the modification request comprises an indication that the dual steer functionality is supported and an indication that a request type of the modification request is for an existing PDU session. [ 0189] In a ninth example, the method of the eighth example, further comprising processing, based on signaling received from the first access network, an establishment command indicating the first PDU session has been modified, wherein the establishment command comprises the PDU session ID for the first PDU session and a dual steer container comprising information related to the dual steer functionality.

[ 0190 ] In a tenth example, the method of the eighth example, further comprising processing, based on signaling received from the first access network, a modification reject message indicating the first access network has not modified the first PDU session, wherein the modification reject message comprises a cause code indicating a reason for not modifying the first PDU session.

[ 0191 ] In an eleventh example, the method of the first example, further comprising generating, for transmission to the first access network, a registration request for the first access network to cause the first access network supporting the dual steer functionality to be a primary access.

[ 0192 ] In a twelfth example, the method of the eleventh example, wherein the registration request comprises an indication of the dual steer functionality and an identification.

[ 0193] In a thirteenth example, the method of the twelfth example, wherein the identification comprises a subscription permanent identifier (SUP I).

[ 0194 ] In a fourteenth example, the method of the eleventh example, wherein generating the registration request is based on type of first access network and a connection to a core network so as to receive all paging and mobile terminated messages over the primary access.

[ 0195 ] In a fifteenth example, the method of the eleventh example, further comprising processing, based on signaling received from the first access network, a registration accept message indicating the first access network is the primary access for a service. [ 0196] In a sixteenth example, the method of the fifteenth example, wherein the registration accept message comprises a Fifth Generation Globally Unique Temporary Identifier (5G-GUTI), an indication of public land mobile networks (PLMNs) that support the dual steer functionality and an indication that a subscription supports dual steer functionality.

[ 0197 ] In a seventeenth example, the method of the first example, further comprising determining the first access network does not satisfy criteria to operate as a preferred access for a service being executed, generating, for transmission to the first access network, a session release message for the first access network to release the first PDU session and processing, based on signaling received from the first access network, a session release command indicating the first access network has released the first PDU session, wherein the second access network supporting the second PDU session operates as the preferred access for the service being executed based on URSP rules.

[ 0198 ] In an eighteenth example, the method of the seventeenth example, further comprising determining the first access network does not satisfy the criteria based on a link quality of the first access network.

[ 0199] In a nineteenth example, the method of the seventeenth example, further comprising generating, for transmission to the first access network, a third request to establish a third PDU session with the first access network, wherein the third request comprises an indication that the dual steer functionality is supported and processing, based on signaling received from the first access network, a third accept message indicating the third PDU session is established with the first access network, wherein the third accept message further comprises a PDU session ID for the third PDU session.

[ 0200 ] In a twentieth example, the method of the first example, further comprising generating, for transmission to the first access network, a service request for the first access network to establish user plane resources over the first access network of the dual steer functionality for a service being executed and for the first access network to be a primary access. [ 0201 ] In a twenty first example, the method of the twentieth example, wherein the service request comprises an indication of the dual steer functionality and an identification.

[ 0202 ] In a twenty second example, the method of the twenty first example, wherein the identification comprises a subscription permanent identifier (SUPI).

[ 0203] In a twenty third example, the method of the twentieth example, wherein generating the service request for the first access network to be a primary access is based on type of first access network and a connection to core network so as to receive all paging and mobile terminated messages over the primary access.

[ 0204 ] In a twenty fourth example, the method of the twentieth example, further comprising processing, based on signaling received from the first access network, a service accept message indicating the first access network is the primary access for the service.

[ 0205 ] In a twenty fifth example, the method of the twenty fourth example, wherein the service accept message comprises a Fifth Generation Globally Unique Temporary Identifier (5G- GUTI), an indication of public land mobile networks (PLMNs) that support the dual steer functionality and an indication that a subscription supports dual steer functionality.

[ 0206] In a twenty sixth example, the method of the first example, further comprising determining the first access network does not satisfy criteria to operate as a preferred access for a service being executed based on UE Route Selection Policy (URSP) rules, generating, for transmission to the first access network, a session suspend request for the first access network to suspend the first PDU session and processing, based on signaling received from the first access network, a session suspend accept message indicating the first access network has suspended the first PDU session, wherein the second PDU session operates as the preferred access for the service. [ 0207 ] In a twenty seventh example, the method of the twenty sixth example, wherein determining the first access network does not satisfy the criteria to be the preferred access is based on a link quality of the first access network.

[ 0208 ] In a twenty eighth example, the method of the twenty sixth example, further comprising generating, for transmission to the first access network, a session resume request to resume the first PDU session with the first access network and processing, based on signaling received from the first access network, a session resume accept message indicating the first PDU session has been resumed by the first access network.

[ 0209] In a twenty ninth example, one or more processors configured to perform any of the methods of the first through twenty eighth examples.

[ 0210 ] In a thirtieth example, a user equipment (UE) configured to perform any of the methods of the first through twenty eighth examples.

[ 0211 ] In a thirty first example, a method, comprising processing, based on signaling received from a first user equipment (UE) of a dual steer functionality UE, a first request message to establish a first Protocol Data Unit (PDU) session with a first access network, wherein the first request message comprises an indication that the first UE supports a dual steer functionality, selecting a session management function (SMF) and a user plane function (UPF) to establish the first PDU session with the first UE, reporting an SMF identification (ID) of the SMF to a Unified Data Management (UDM) function and generating, for transmission to the first UE, a first accept message indicating the first PDU session is established with the first access network, wherein the first accept message further comprises a PDU session identification (ID) for the first PDU session.

[ 0212 ] In a thirty second example, the method of the thirty first example, wherein the first request message further comprises an indication that a request type of the first request message is an initial request. [ 0213] In a thirty third example, the method of the thirty first example, wherein the first request message further comprises an indication that the PDU session is a Multi-Access DualSteer PDU (MADS-PDU) session.

[ 0214 ] In a thirty fourth example, the method of the thirty first example, wherein the first accept message further comprises a dual steer container comprising information related to the dual steer functionality.

[ 0215 ] In a thirty fifth example, the method of the thirty fourth example, wherein the information related to the dual steer functionality comprises rules that are processed by the UPF for selecting the first access network or a second access network to exchange traffic for a service being executed by the dual steer UE and parameters and parameter values associated with the rules.

[ 0216] In a thirty sixth example, the method of the thirty first example, further comprising processing, based on signaling received from the first UE, a modification request to modify the first PDU session with the first access network, wherein the modification request comprises an indication that the first UE supports the dual steer functionality and an indication that a request type of the modification request is for an existing PDU session.

[ 0217 ] In a thirty seventh example, the method of the thirty sixth example, further comprising generating, for transmission to the first UE, an establishment command indicating the first PDU session has been modified, wherein the establishment command comprises the PDU session ID for the first PDU session and a dual steer container comprising information related to the dual steer functionality.

[ 0218 ] In a thirty eighth example, the method of the thirty sixth example, further comprising generating, for transmission to the first UE, a modification reject message indicating the first access network has not modified the first PDU session, wherein the modification reject message comprises a cause code indicating a reason for not modifying the first PDU session. [ 0219] In a thirty ninth example, the method of the thirty first example, further comprising processing, based on signaling received from the first UE, a registration request for the first access network to cause the first access network of the dual steer functionality to be a primary access for a service being executed by the dual steer UE.

[ 0220 ] In a fortieth example, the method of the thirty ninth example, wherein the registration request comprises an indication of the dual steer functionality and an identification of the first UE.

[ 0221 ] In a forty first example, the method of the fortieth example, wherein the identification of the first UE comprises a Subscription Concealed Identifier (SUCI) of the first UE.

[ 0222 ] In a forty second example, the method of the thirty ninth example, further comprising generating, for transmission to the first UE, a registration accept message indicating the first access network is the primary access for the dual steer functionality UE.

[ 0223 ] In a forty third example, the method of the forty second example, wherein the registration accept message comprises a Fifth Generation Globally Unique Temporary Identifier (5G-GUTI) of the first UE, an indication of public land mobile networks (PLMNs) that support the dual steer functionality and an indication that a subscription of the first UE supports dual steer functionality.

[ 0224 ] In a forty fourth example, the method of the thirty first example, further comprising processing, based on signaling received from the first UE, a session release message for the first access network to release the first PDU session and generating, for transmission to the first UE, a session release command indicating the first access network has released the first PDU session, wherein a second access network operates as a preferred access for a second PDU session supporting a service being executed by the dual steer functionality UE. [ 0225 ] In a forty fifth example, the method of the forty fourth example, further comprising processing, based on signaling received from the first UE, a request to establish a new PDU session with the first access network, wherein the request comprises an indication that the first UE supports a dual steer functionality and generating, for transmission to the first UE, an accept message indicating the new PDU session is established with the first access network, wherein the accept message further comprises a PDU session ID for the new PDU session.

[ 0226] In a forty sixth example, the method of the thirty first example, further comprising processing, based on signaling received from the first UE, a service request for the first access network to cause the first access network of the dual steer functionality to be a primary access for a service being executed by the dual steer UE.

[ 0227 ] In a forty seventh example, the method of the forty sixth example, wherein the service request comprises an indication of the dual steer functionality and an identification of the first UE.

[ 0228 ] In a forty eighth example, the method of the forty seventh example, wherein the identification of the first UE comprises a Subscription Concealed Identifier (SUCI) of the first UE.

[ 0229] In a forty ninth example, the method of the forty sixth example, further comprising generating, for transmission to the first UE, a service accept message indicating the first PDU session is the primary access for the service being executed by the dual steer UE.

[ 0230 ] In a fiftieth example, the method of the forty ninth example, wherein the service accept message comprises a Fifth Generation Globally Unique Temporary Identifier (5G-GUTI) of the first UE, an indication of public land mobile networks (PLMNs) that support the dual steer functionality and an indication that a subscription of the first UE supports dual steer functionality. [ 0231 ] In a fifty first example, the method of the thirty first example, further comprising processing, based on signaling received from the first UE, a session suspend request for the first access network to suspend the first PDU session and generating, for transmission to the first UE, a session suspend accept message indicating the first access network has suspended the first PDU session, wherein a second access network operates as a preferred access for a second PDU session supports a service being executed by the dual steer UE.

[ 0232 ] In a fifty second example, the method of the fifty first example, further comprising processing, based on signaling received from the first UE, a session resume request to resume the first PDU session with the first access network and generating, for transmission to the first UE, a session resume accept message indicating the first PDU session has been resumed by the first access network.

[ 0233 ] In a fifty third example, the method of the thirty first example, further comprising verifying with the UDM function that a subscription of the first UE supports the dual steer functionality.

[ 0234 ] In a fifty fourth example, the method of the thirty first example, further comprising determining whether the first PDU session is a home routed session or a local breakout session.

[ 0235 ] In a fifty fifth example, one or more processors configured to perform any of the methods of the thirty first through fifty fourth examples.

[ 0236 ] In a fifty sixth example, a network function configured to perform any of the methods of the thirty first through fifty fourth examples.

[ 0237 ] In a fifty seventh example, a method, comprising processing, based on signaling received from a first user equipment (UE) of a dual steer functionality UE, a first request message to establish a first Protocol Data Unit (PDU) session with a first access network, wherein the first request message comprises an indication that a dual steer functionality is supported and Session identification (ID) of a second PDU session associated with the dual steer functionality UE, determining a Session Management Function (SMF) hosting the second PDU session based on a mapping of a SMF ID of the SMF that is hosting a second PDU session and the Session ID stored in a Unified Data Management (UDM) function, selecting the SMF hosting the second PDU session to establish the first PDU session with the first UE and generating, for transmission to the first UE, an accept message indicating the first PDU session is established with the first access network.

[ 0238 ] In a fifty eighth example, one or more processors configured to perform the method of the fifty seventh example.

[ 0239 ] In a fifty sixth example, a network function configured to perform the method of the fifty seventh example.

[ 0240 ] Those skilled in the art will understand that the above-described example embodiments may be implemented in any suitable software or hardware configuration or combination thereof. An example hardware platform for implementing the example embodiments may include, for example, an Intel x86 based platform with compatible operating system, a Windows OS, a Mac platform and MAC OS, a mobile device having an operating system such as iOS, Android, etc. The example embodiments of the above described method may be embodied as a program containing lines of code stored on a non-transitory computer readable storage medium that, when compiled, may be executed on a processor or microprocessor.

[ 0241 ] Although this application described various embodiments each having different features in various combinations, those skilled in the art will understand that any of the features of one embodiment may be combined with the features of the other embodiments in any manner not specifically disclaimed or which is not functionally or logically inconsistent with the operation of the device or the stated functions of the disclosed embodiments. [ 0242 ] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.

[ 0243 ] It will be apparent to those skilled in the art that various modifications may be made in the present disclosure, without departing from the spirit or the scope of the disclosure. Thus, it is intended that the present disclosure cover modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalent.

Claims

What is claimed:

1 . An apparatus comprising processing circuitry configured to: generate, for transmission to a first access network, a first request message to establish a first Protocol Data Unit (PDU) session with the first access network, wherein the first request message comprises an indication that a dual steer functionality is supported; process, based on signaling received from the first access network, a first accept message indicating the first PDU session is established with the first access network, wherein the first accept message further comprises a PDU session identification (ID) for the first PDU session; generate, for transmission to a second access network, a second request message to establish a second PDU session with the second access network, wherein the second request message comprises an indication that the dual steer functionality is supported and the PDU session ID for the first PDU session; and process, based on signaling received from the second access network, a second accept message indicating the second PDU session is established with the second access network, wherein the first PDU session and the second PDU session are associated PDU sessions of the dual steer functionality.

2. The apparatus of claim 1, wherein the first request message further comprises an indication that a request type of the first request message is an initial request.

3. The apparatus of claim 2, wherein the second request message further comprises an indication that a request type of the second request message is an initial request.

4. The apparatus of claim 1, wherein the first request message further comprises an indication that the first PDU session is a Multi-Access DualSteer PDU (MADS-PDU) session and the second request message further comprises an indication that the second PDU session is the MADS-PDU session.

5. The apparatus of claim 1, wherein the first PDU session is a separate PDU session from the second PDU session.

6. The apparatus of claim 1, wherein the first accept message further comprises a dual steer container comprising information related to the dual steer functionality.

7. The apparatus of claim 6, wherein the information related to the dual steer functionality comprises UE Route Selection Policy (URSP) rules related to selecting the first access network or the second access network to exchange traffic for a service being executed and parameters and parameter values associated with the URSP rules.

8. The apparatus of claim 1, wherein the processing circuitry is further configured to: generate, for transmission to the first access network, a modification request to modify the first PDU session with the first access network, wherein the modification request comprises an indication that the dual steer functionality is supported and an indication that a request type of the modification request is for an existing PDU session.

9. The apparatus of claim 8, wherein the processing circuitry is further configured to: process, based on signaling received from the first access network, an establishment command indicating the first PDU session has been modified, wherein the establishment command comprises the PDU session ID for the first PDU session and a dual steer container comprising information related to the dual steer functionality.

10. The apparatus of claim 8, wherein the processing circuitry is further configured to: process, based on signaling received from the first access network, a modification reject message indicating the first access network has not modified the first PDU session, wherein the modification reject message comprises a cause code indicating a reason for not modifying the first PDU session.

11. The apparatus of claim 1, wherein the processing circuitry is further configured to: generate, for transmission to the first access network, a registration request for the first access network to cause the first access network supporting the dual steer functionality to be a primary access.

12. The apparatus of claim 11, wherein the registration request comprises an indication of the dual steer functionality and an identification.

13. The apparatus of claim 12, wherein the identification comprises a subscription permanent identifier (SUPI).

14. The apparatus of claim 11, wherein the processing circuity generates the registration request based on type of first access network and a connection to a core network so as to receive all paging and mobile terminated messages over the primary access.

15. The apparatus of claim 11, wherein the processing circuitry is further configured to: process, based on signaling received from the first access network, a registration accept message indicating the first access network is the primary access for a service.

16. The apparatus of claim 15, wherein the registration accept message comprises a Fifth Generation Globally Unique Temporary Identifier (5G-GUTI), an indication of public land mobile networks (PLMNs) that support the dual steer functionality and an indication that a subscription supports dual steer functionality.

17. The apparatus of claim 1, wherein the processing circuitry is further configured to: determine the first access network does not satisfy criteria to operate as a preferred access for a service being executed; generate, for transmission to the first access network, a session release message for the first access network to release the first PDU session; and process, based on signaling received from the first access network, a session release command indicating the first access network has released the first PDU session, wherein the second access network supporting the second PDU session operates as the preferred access for the service being executed based on URSP rules.

18. A method, compri si ng : processing, based on signaling received from a first user equipment (UE) of a dual steer functionality UE, a first request message to establish a first Protocol Data Unit (PDU) session with a first access network, wherein the first request message comprises an indication that the first UE supports a dual steer functionality; selecting a session management function (SMF) and a user plane function (UPF) to establish the first PDU session with the first UE; reporting an SMF identification (ID) of the SMF to a Unified Data Management (UDM) function; and generating, for transmission to the first UE, a first accept message indicating the first PDU session is established with the first access network, wherein the first accept message further comprises a PDU session identification (ID) for the first PDU session.

19. The method of claim 18, wherein the first request message further comprises an indication that a request type of the first request message is an initial request.

20. The method of claim 18, wherein the first request message further comprises an indication that the PDU session is a Multi-Access DualSteer PDU (MADS-PDU) session.