Establishing data network connection through two 3GPP accesses by dual steering

Abstract

Systems and methods for establishing a data network connection through two access networks are disclosed. In one embodiment, a method comprises, at a first Access and Mobility Management Function (AMF), receiving, via the first access network, a Protocol Data Unit (PDU) session establishment request from a device for a first subscription permanent identifier (SUPI), wherein the PDU session establishment request comprises the first SUPI, a PDU session identifier, and a dual steering (DS) indicator that indicates that the PDU session establishment request is a request to establish a DS PDU session. The method further comprises, at the first AMF, selecting a Session Management Function (SMF) and sending, to the SMF, a request to create a session management (SM) context for the requested PDU session, the request comprising the first SUPI, the PDU session identifier, and the DS indicator. In this manner, connection using two access networks is enabled.

Description

ESTABLISHING DATA NETWORK CONNECTION THROUGH TWO 3GPP ACCESSES BY DUAL STEERINGRelated Applications

[0001] This application claims the benefit of provisional patent application serial number 63 / 620,317, filed January 12, 2024, the disclosure of which is hereby incorporated herein by reference in its entirety.Technical Field

[0002] The present disclosure relates to a wireless communication system and in particular establishing a data network connection through two 3rdGeneration Partnership Project (3GPP) access networks.Background

[0003] Currently, a User Equipment (UE) can simultaneously be connected to a 5thGeneration (5G) system using one Non-3rdGeneration Partnership Project (3GPP) access and one 3GPP access using Access Traffic Steering, Switching, and Splitting (ATSSS). For the nonroaming case, the architecture is as shown in Figure 1 and described in 3GPP Technical Specification (TS) 23.501 vl8.3.0 (see, e.g., Section 4.2.10 of 3GPP TS 23.501 V18.3.0), an excerpt of which is provided below.***** START EXCERPT FROM 3GPP 23.501 *****4.2.10 Architecture Reference Model for ATSSS SupportIn order to support the ATSSS feature, the 5G System Architecture is extended as shown in Figure 4.2.10-1, Figure 4.2.10-2 and Figure 4.2.10-3. The additional functionality that is supported by the UE and the network functions shown in these figures is specified in clause 5.32 below. In summary:- The UE supports one or more of the steering functionalities specified in clause 5.32.6, i.e. the MPTCP functionality, the MPQUIC functionality and the ATSSS-LL functionality. Each steering lunctionality in the UE enables traffic steering, switching and splitting across 3 GPP access and non-3GPP access, in accordance with the ATSSS rules provided by the network. The ATSSS-LL functionality is mandatory in the UE for MA PDU Session of type Ethernet.- The UPF may support the MPTCP Proxy functionality, which communicates with the MPTCP functionality in the UE by using the MPTCP protocol (IETF RFC 8684

[0081] ), as defined in clause 5.32.6.2.1.- The UPF may support the MPQUIC Proxy functionality, which communicates with the MPQUIC functionality in the UE by using the QUIC protocol (RFC 9000

[0166] , RFC 9001

[0167] , RFC 9002

[0168] ) and its multipath extensions (draft-ietf-quic-multipath

[0174] ), as defined in clause 5.32.6.2.2.- The UPF may support ATSSS-LL functionality, which is similar to the ATSSS-LL functionality defined for the UE. There is no user plane protocol defined between the ATSSS-LL functionality in the UE and the ATSSS-LL functionality in the UPF.NOTE 1 : ATSSS-LL functionality is needed in the 5GC for MA PDU Session of type Ethernet.- In addition, the UPF supports Performance Measurement Functionality (PMF), which may be used by the UE to obtain access performance measurements (see clause 5.32.5) over the user-plane of 3GPP access and / or over the user-plane of non-3GPP access.The AMF, SMF and PCF are extended with new functionality that is further discussed in clause 5.32.NOTE 2: The interactions between the UE and PCF that may be required for ATSSS control are specified in TS 23.503

[0045] ,NOTE 3 : The UPF shown in Figure 4.2.10-1 can be connected via an N9 reference point, instead of the N3 reference point.***** END EXCERPT FROM 3GPP 23.501 *****

[0004] For the ATSSS feature, the UE establishes a multi -access (MA) Protocol Data Unit (PDU) session to the User Plane Function (UPF).

[0005] Connecting a DualSteer device to two 3GPP access is a study item in 3GPP Release 19 (see 3 GPP document SI -233371 entitled “New SID on Multi -Access (Dual Steer and ATSSS_Ph4)”) under the topic of Dual Steering (DS). It is required that the User registers to the two accesses with two different Subscription Permanent Identifiers (SUPIs) that are connected to the same subscription. A DualSteer device is a device supporting traffic steering and switching of user data (for different services) across two 3GPP access networks. A DualSteer device can be a single UE or two separate UEs in a single device. In the latter case, each UE is handling one SUPI. Minimum interruption should occur with switching the accesses. Stage 1 requirements for the Dual Steer study have been agreed in SI -233371.Summary

[0006] Systems and methods for establishing a data network connection through two wireless access networks are disclosed. In one embodiment, a method performed in a core network of a wireless communication system for supporting dual steering of data traffic via a first access network and a second access network comprises at a first Access and Mobility Management Function (AMF), receiving, via the first access network, a Protocol Data Unit (PDU) session establishment request from a device for a first subscription permanent identifier (SUPI), wherein the PDU session establishment request comprises the first SUPI, a PDU session identifier, and a dual steering (DS) indicator that indicates that the PDU session establishment request is a request to establish a DS PDU session. The method further comprises, at the first AMF, selecting a Session Management Function (SMF) and sending, to the SMF, a request to create a session management (SM) context for the requested PDU session, the request to create the SM context comprising the first SUPI, the PDU session identifier, and the DS indicator. The method further comprise, at the SMF, receiving the request to create the SM context for the requested PDU session, obtaining a second SUPI associated to the first SUPI for dual steering and informationthat indicates a primary SUPI for the DS PDU session, sending the primary SUPI for the DS PDU session to a Policy and Control Function (PCF) for SM policy association, registering with a first Unified Data Management (UDM) using the first SUPI and the PDU session identifier, and registering with a second UDM (which may be the same UDM as the first UDM or a different UDM) using the second SUPI and the PDU session identifier.

[0007] In one embodiment, the method further comprises, at a second AMF, receiving, via the second access network, a second PDU session establishment request from the device for the second SUPI, wherein the second PDU session establishment request comprises the second SUPI, the PDU session identifier, and a DS indicator that indicates that the second PDU session establishment request is a request associated to a DS PDU session. The method further comprises, at the second AMF, selecting the SMF based on the PDU session identifier and sending, to the SMF, a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the PDU session identifier, and the DS indicator. In one embodiment, the method further comprises, at the SMF, receiving the request to create the SM context for the requested second PDU session, obtaining the primary SUPI for the DS PDU session, and sending the primary SUPI for the DS PDU session to the PCF for SM policy association.

[0008] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0009] Embodiments of a method performed by a device for dual steering of data traffic via a first access network and a second access network are also disclosed. In one embodiment, the method performed by the device for dual steering of data traffic via a first access network and a second access network comprises sending a first PDU session establishment request for a first SUPI to a first AMF via the first access network, wherein the first PDU session establishment request comprises the first SUPI, a PDU session identifier, and a dual steering, DS, indicator that indicates that the PDU session establishment request is for a DS PDU session. The method further comprises sending a second PDU session establishment request for a second SUPI to a second AMF via the second access network, wherein the second PDU session establishment request comprises the second SUPI, the PDU session identifier, and a DS indicator that indicates that the second PDU session establishment request is for a DS PDU session.

[0010] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0011] Corresponding embodiments of a device are also disclosed. In one embodiment, the device comprises a single User Equipment (UE) associated to both the first SUPI and the secondSUPI. In another embodiment, the device comprises a first UE associated to the first SUPI and a second UE associated to the second SUPI.

[0012] Embodiments of a method performed by an AMF for dual steering of data traffic via a first access network and a second access network are also disclosed. In one embodiment, the method performed by the AMF for dual steering of data traffic via a first access network and a second access network comprises receiving, via the first access network, a PDU session establishment request from a device for a first SUPI, wherein the PDU session establishment request comprises the first SUPI, a PDU session identifier, and a DS indicator that indicates that the PDU session establishment request is for a DS PDU session. The method further comprises selecting an SMF and sending, to the SMF, a request to create a session management (SM) context for the requested PDU session, the request to create the SM context comprising the first SUPI, the PDU session identifier, and the DS indicator.

[0013] In one embodiment, the PDU session identifier is common for the requested PDU session and a second PDU session requested by the device for the DS PDU session via the second access network.

[0014] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0015] Corresponding embodiments of an AMF are also disclosed.

[0016] In another embodiment, a method performed by an AMF for dual steering of data traffic via a first access network and a second access network comprises receiving , via the second access network, a PDU session establishment request from a device for a second SUPI, wherein the PDU session establishment request comprises the second SUPI, a PDU session identifier, and a dual steering, DS, indicator that indicates that the PDU session establishment request is for a DS PDU session. The method further comprises selecting an SMF based on the PDU session identifier and sending, to the SMF, a request to create an SM context for the requested PDU session, the request to create the SM context comprising the second SUPI, the PDU session identifier, and the DS indicator.

[0017] In one embodiment, the PDU session identifier is common for the requested PDU session and a first PDU session requested by the device for the DS PDU session via the first access network.

[0018] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0019] Corresponding embodiments of an AMF are also disclosed.

[0020] Embodiments of a method performed by an SMF for dual steering of data traffic via a first access network and a second access network are also disclosed. In one embodiment, themethod performed by an SMF for dual steering of data traffic via a first access network and a second access network comprises receiving a request to create an SM context for a first requested PDU session for dual steering, the request to create the SM context for the first requested PDU session comprising a first SUPI, a PDU session identifier, and a DS indicator that indicates that the first requested PDU session is for a DS PDU session. The method further comprises obtaining a second SUPI associated to the first SUPI for dual steering and information that indicates a primary SUPI for the DS PDU session, sending the primary SUPI for the DS PDU session to a Policy and Control Function (PCF) for SM policy association, registering with a first Unified Data Management (UDM) using the first SUPI and the PDU session identifier, and registering with a second UDM using the second SUPI and the PDU session identifier.

[0021] In one embodiment, the method further comprises receiving a request to create a SM context for a second requested PDU session for the dual steering, the request to create the SM context for the second requested PDU session comprising the second SUPI, the PDU session identifier, and a DS indicator that indicates that the second requested PDU session is for a DS PDU session. The method further comprises obtaining the primary SUPI for the DS PDU session and sending the primary SUPI for the DS PDU session to the PCF (226) for SM policy association.

[0022] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0023] Corresponding embodiments of an SMF are also disclosed.

[0024] In another embodiment, a method performed in a core network of a wireless communication system for supporting dual steering of data traffic via a first access network and a second access network comprises at a first AMF, receiving, via the first access network, a PDU session establishment request from a device for a first SUPI, wherein the PDU session establishment request comprises the first SUPI, a first PDU session identifier, and a DS session identifier. The method further comprises, at the first AMF, selecting an SMF and sending, to the SMF, a request to create a SM context for the requested PDU session, the request to create the SM context comprising the first SUPI, the PDU session identifier, and the DS session identifier. The method further comprises, at the SMF, receiving the request to create the SM context for the requested PDU session, obtaining a second SUPI associated to the first SUPI for dual steering and information that indicates a primary SUPI for the DS session, sending the primary SUPI for the DS session to a PCF for SM policy association, registering with a first UDM using the first SUPI and the first PDU session identifier, and registering with a second UDM using the second SUPI and the DS session identifier.

[0025] In one embodiment, the method further comprises at a second AMF, receiving, via the second access network, a second PDU session establishment request from the device for the second SUPI, wherein the second PDU session establishment request comprises the second SUPI, a second PDU session identifier, and the DS session identifier. The method further comprises, at the second AMF, selecting the SMF based on the DS session identifier and sending, to the SMF, a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the second PDU session identifier, and the DS session identifier. In one embodiment, the method further comprises, at the SMF, receiving the request to create the SM context for the requested second PDU session, obtaining the primary SUPI for the DS session, and sending the primary SUPI for the DS session to the PCF for SM policy association.

[0026] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0027] In one embodiment, a method performed by a device for dual steering of data traffic via a first access network and a second access network comprises sending a first PDU session establishment request for a first SUPI to a first AMF via the first access network, wherein the first PDU session establishment request comprises the first SUPI, a first PDU session identifier, and a DS session identifier and sending a second PDU session establishment request for a second SUPI to a second AMF via the second access network, wherein the second PDU session establishment request comprises the second SUPI, a second PDU session identifier, and the DS session identifier.

[0028] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0029] Corresponding embodiments of a device are also disclosed. In one embodiment, the device comprises a single UE associated to both the first SUPI and the second SUPI. In another embodiment, the device comprises a first UE associated to the first SUPI and a second UE associated to the second SUPI.

[0030] In one embodiment, a method performed by an AMF for dual steering of data traffic via a first access network and a second access network comprises receiving, via the first access network, a PDU session establishment request from a device for a first SUPI, wherein the PDU session establishment request comprises the first SUPI, a first PDU session identifier, and a dual steering, DS, session identifier. The method further comprises selecting an SMF and sending, to the SMF, a request to create an SM context for the requested PDU session, the request to create the SM context comprising the first SUPI, the first PDU session identifier, and the DS session identifier.

[0031] In one embodiment, the DS session identifier is common for the requested PDU session and a second PDU session requested by the device for the DS session via the second access network.

[0032] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0033] Corresponding embodiments of an AMF are also disclosed.

[0034] In another embodiment, a method performed by an AMF for dual steering of data traffic via a first access network and a second access network comprises receiving, via the second access network, a PDU session establishment request from a device for a second SUP I, wherein the PDU session establishment request comprises the second SUP I, a second PDU session identifier, and a dual steering, DS, session identifier. The method further comprises selecting an SMF based on the DS session identifier and sending, to the SMF, a request to create a SM context for the requested PDU session, the request to create the SM context comprising the second SUPI, the second PDU session identifier, and the DS session identifier.

[0035] In another embodiment, the DS session identifier is common for the requested PDU session and a first PDU session requested by the device for the DS PDU session via the first access network.

[0036] In another embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0037] Corresponding embodiments of an AMF are also disclosed.

[0038] In one embodiment, a method performed by an SMF for dual steering of data traffic via a first access network and a second access network comprises receiving a request to create a SM context for a first requested PDU session for dual steering, the request to create the SM context for the first requested PDU session comprising a first SUPI, a first PDU session identifier, and a DS session identifier. The method further comprises obtaining a second SUPI associated to the first SUPI for dual steering and information that indicates a primary SUPI for the DS session, sending the primary SUPI for the DS session to a PCF for SM policy association, registering with a first UDM using the first SUPI and the first PDU session identifier, and registering with a second UDM using the second SUPI and the DS session identifier.

[0039] In one embodiment, the method further comprises receiving a request to create a SM context for a second requested PDU session for the dual steering, the request to create the SM context for the second requested PDU session comprising the second SUPI, a second PDU session identifier, and the DS session identifier. The method further comprises obtaining the primary SUPI for the DS session and sending the primary SUPI for the DS session to the PCF (226) for SM policy association.

[0040] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0041] Corresponding embodiments of an SMF are also disclosed.

[0042] In another embodiment, a method performed in a core network of a wireless communication system for supporting dual steering of data traffic via a first access network and a second access network comprises at a first AMF, receiving, via the first access network, a PDU session establishment request from a device for a first SUPI, wherein the PDU session establishment request comprises the first SUPI, a PDU session identifier, and a DS indicator that indicates that the PDU session establishment request is a request to establish a DS PDU session. The method further comprises, at the first AMF, selecting a first SMF and sending, to the first SMF, a request to create an SM context for the requested first PDU session, the request to create the SM context comprising the first SUPI, the PDU session identifier, and the DS indicator. The method further comprises, at the first SMF, receiving the request to create the SM context for the requested first PDU session, obtaining information that indicates a primary SUPI for the DS PDU session, sending the primary SUPI for the DS PDU session to a PCF for SM policy association, and registering with a first UDM using the first SUPI and the PDU session identifier.

[0043] In one embodiment, the method further comprises, at a second AMF, receiving , via the second access network, a second PDU session establishment request from the device for the second SUPI, wherein the second PDU session establishment request comprises the second SUPI, the PDU session identifier, and a DS indicator that indicates that the second PDU session establishment request is a request associated to a DS PDU session. The method further comprises, at the second AMF, selecting a second SMF and sending, to the second SMF, a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the PDU session identifier, and the DS indicator. In one embodiment, the method further comprises, at the second SMF, receiving the request to create the SM context for the requested second PDU session, obtaining the first SUPI associated to the second SUPI for dual steering, obtaining an SMF identity of the first SMF based on the first SUPI, and sending, to the second AMF, a request for redirection of the second AMF to the first SMF, the request for redirection comprising the SMF identity of the first SMF. In one embodiment, the method further comprises, at the second AMF, receiving the request for redirection and, in response to the request for redirection, sending, to the first SMF, a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the PDU session identifier, and the DS indicator. In one embodiment, the method further comprises at the first SMF, receiving the request to create a SM context for the requested second PDUsession, obtaining the primary SUPI for the DS PDU session, and sending the primary SUPI for the DS PDU session to the PCF for SM policy association.

[0044] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0045] In one embodiment, a method performed by a device for dual steering of data traffic via a first access network and a second access network comprises sending a first PDU session establishment request for a first SUPI to a first AMF via the first access network, wherein the first PDU session establishment request comprises the first SUPI, a PDU session identifier, and a DS indicator that indicates that the PDU session establishment request is for a DS PDU session. The method further comprises sending a second PDU session establishment request for a second SUPI to a second AMF via the second access network, wherein the second PDU session establishment request comprises the second SUPI, the PDU session identifier, and a DS indicator that indicates that the second PDU session establishment request is for a DS PDU session.

[0046] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0047] Corresponding embodiments of a device are also disclosed. In one embodiment, the device comprises a single UE associated to both the first SUPI and the second SUPI. In another embodiment, the device comprises a first UE associated to the first SUPI and a second UE associated to the second SUPI.

[0048] In one embodiment, a method performed by an AMF for dual steering of data traffic via a first access network and a second access network comprises receiving, via the first access network, a PDU session establishment request from a device for a first SUPI, wherein the PDU session establishment request comprises the first SUPI, a PDU session identifier, and a DS indicator that indicates that the PDU session establishment request is for a DS PDU session. The method further comprises selecting an SMF and sending, to the SMF, a request to create an SM context for the requested PDU session, the request to create the SM context comprising the first SUPI, the PDU session identifier, and the DS indicator.

[0049] In one embodiment, the PDU session identifier is common for the requested PDU session and a second PDU session requested by the device for the DS PDU session via the second access network.

[0050] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0051] Corresponding embodiments of an AMF are also disclosed.

[0052] In one embodiment, a method performed by an AMF for dual steering of data traffic via a first access network and a second access network comprises receiving, via the secondaccess network, a PDU session establishment request from a device for a second SUP I, wherein the PDU session establishment request comprises the second SUP I, a PDU session identifier, and a DS indicator that indicates that the PDU session establishment request is for a DS PDU session. The method further comprises selecting a second SMF and sending, to the second SMF, a request to create an SM context for the requested PDU session, the request to create the SM context comprising the second SUPI, the PDU session identifier, and the DS indicator. The method further comprises receiving, from the second SMF, a request for redirection of the AMF to a first SMF and, in response to the request for redirection, sending, to the first SMF, a request to create a SM context for the requested PDU session, the request to create the SM context comprising the second SUPI, the PDU session identifier, and the DS indicator.

[0053] In one embodiment, the PDU session identifier is common for the requested PDU session and a first PDU session requested by the device for the DS PDU session via the first access network.

[0054] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0055] Corresponding embodiments of an AMF are also disclosed.

[0056] In one embodiment, a method performed by an SMF for dual steering of data traffic via a first access network and a second access network comprises receiving a request to create an SM context for a first requested PDU session for dual steering, the request to create the SM context for the first requested PDU session comprising a first SUPI, a PDU session identifier, and a DS indicator that indicates that the first requested PDU session is for a DS PDU session. The method further comprises obtaining information that indicates a primary SUPI for the DS PDU session, sending the primary SUPI for the DS PDU session to a PCF for SM policy association, and registering with a first UDM using the first SUPI and the PDU session identifier.

[0057] In one embodiment, the method further comprises receiving a request to create a SM context for a second requested PDU session for the dual steering, the request to create the SM context for the second requested PDU session comprising the second SUPI, the PDU session identifier, and a DS indicator that indicates that the second requested PDU session is for a DS PDU session. The method further comprises obtaining the primary SUPI for the DS PDU session and sending the primary SUPI for the DS PDU session to the PCF (226) for SM policy association.

[0058] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0059] Corresponding embodiments of an SMF are also disclosed.

[0060] In one embodiment, a method performed by a second SMF for dual steering of data traffic via a first access network and a second access network comprises receiving, from a second AMF, a request to create an SM context for a second requested PDU session for dual steering, the request to create the SM context for the second requested PDU session comprising a second SUPI, a PDU session identifier, and a DS indicator that indicates that the second requested PDU session is for a DS PDU session. The method further comprises obtaining a first SUPI associated to the second SUPI for dual steering, obtaining an SMF identity of a first SMF based on the first SUPI, and sending, to the second AMF, a request for redirection of the second AMF to the first SMF, the request for redirection comprising the SMF identity of the first SMF.

[0061] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0062] Corresponding embodiments of a second SMF are also disclosed.

[0063] In another embodiment, a method performed in a core network of a wireless communication system for supporting dual steering of data traffic via a first access network and a second access network comprises, at a first AMF, receiving, via the first access network, a PDU session establishment request from a device for a first SUPI, wherein the PDU session establishment request comprises the first SUPI, a first PDU session identifier, and a DS session identifier. The method further comprises, at the first AMF, selecting a first SMF and sending, to the first SMF, a request to create an SM context for the requested first PDU session, the request to create the SM context comprising the first SUPI, the first PDU session identifier, and the DS session identifier. The method further comprises, at the first SMF, receiving the request to create the SM context for the requested first PDU session, obtaining information that indicates a primary SUPI for the DS session, sending the primary SUPI for the DS session to a PCF for SM policy association, and registering with a first UDM using the first SUPI, the first PDU session identifier, and optionally the DS Session identifier.

[0064] In one embodiment, the method further comprises, at a second AMF, receiving, via the second access network, a second PDU session establishment request from the device for the second SUPI, wherein the second PDU session establishment request comprises the second SUPI, a second PDU session identifier, and the DS session identifier. The method further comprises, at the second AMF, selecting a second SMF and sending, to the second SMF, a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the second PDU session identifier, and the DS session identifier. In one embodiment, the method further comprises, at the second SMF, receiving the request to create the SM context for the requested second PDU session, obtaining the first SUPI associated to the second SUPI for dual steering,obtaining an SMF identity of the first SMF based on the first SUPI and the DS session identifier, and sending, to the second AMF, a request for redirection of the second AMF to the first SMF, the request for redirection comprising the SMF identity of the first SMF. In one embodiment, the method further comprises, at the second AMF, receiving the request for redirection and, in response to the request for redirection, sending, to the first SMF, a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the second PDU session identifier, and the DS session identifier. In one embodiment, the method further comprises, at the first SMF, receiving the request to create a SM context for the requested second PDU session, obtaining the primary SUPI for the DS session, and sending the primary SUPI for the DS session to the PCF for SM policy association.

[0065] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0066] In one embodiment, a method performed by a device for dual steering of data traffic via a first access network and a second access network comprises sending a first PDU session establishment request for a first SUPI to a first AMF via the first access network, wherein the first PDU session establishment request comprises the first SUPI, a first PDU session identifier, and a DS session identifier. The method further comprises sending a second PDU session establishment request for a second SUPI to a second AMF via the second access network, wherein the second PDU session establishment request comprises the second SUPI, a second PDU session identifier, and the DS session identifier.

[0067] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0068] Corresponding embodiments of a device are also disclosed. In one embodiment, the device comprises a single UE associated to both the first SUPI and the second SUPI. In another embodiment, the device comprises a first UE associated to the first SUPI and a second UE associated to the second SUPI.

[0069] In one embodiment, a method performed by an AMF for dual steering of data traffic via a first access network and a second access network comprises receiving, via the first access network, a PDU session establishment request from a device for a first SUPI, wherein the PDU session establishment request comprises the first SUPI, a first PDU session identifier, and a DS session identifier. The method further comprises selecting an SMF and sending, to the SMF, a request to create an SM context for the requested PDU session, the request to create the SM context comprising the first SUPI, the first PDU session identifier, and the DS session identifier.

[0070] In one embodiment, the DS session identifier is common for the requested PDU session and a second PDU session requested by the device for the DS session via the second access network.

[0071] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0072] Corresponding embodiments of an AMF are also disclosed.

[0073] In one embodiment, a method performed by a second AMF for dual steering of data traffic via a first access network and a second access network comprises receiving, via the second access network, a PDU session establishment request from a device for a second SUP I, wherein the PDU session establishment request comprises the second SUP I, a second PDU session identifier, and a DS session identifier. The method further comprises selecting a second SMF and sending, to the second SMF, a request to create an SM context for the requested PDU session, the request to create the SM context comprising the second SUPI, the second PDU session identifier, and the DS session identifier. The method further comprises receiving, from the second SMF, a request for redirection of the second AMF to a first SMF, the request for redirection comprising an SMF identity of the first SMF (224). The method further comprises, in response to the request for redirection, sending, to the first SMF, a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the second PDU session identifier, and the DS session identifier.

[0074] In one embodiment, the DS session identifier is common for the requested PDU session and a first PDU session requested by the device for the DS session via the first access network.

[0075] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0076] Corresponding embodiments of a second AMF are also disclosed.

[0077] In one embodiment, a method performed by a first SMF for dual steering of data traffic via a first access network and a second access network comprises receiving a request to create an SM context for a first requested PDU session for dual steering, the request to create the SM context for the first requested PDU session comprising a first SUPI, a first PDU session identifier, and a DS session identifier. The method further comprises obtaining information that indicates a primary SUPI for the DS PDU session, sending the primary SUPI for the DS session to a PCF for SM policy association, and registering with a first UDM using the first SUPI, the PDU session identifier, and the DS session identifier.

[0078] In one embodiment, the method further comprises receiving a request to create a SM context for a second requested PDU session for the dual steering, the request to create the SM context for the second requested PDU session comprising the second SUPI, the second PDU session identifier, and the DS session identifier. The method further comprises obtaining the primary SUPI for the DS session and sending the primary SUPI for the DS session to the PCF for SM policy association.

[0079] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0080] Corresponding embodiments of a first SMF are also disclosed.

[0081] In one embodiment, a method performed by a second SMF for dual steering of data traffic via a first access network and a second access network comprises receiving, from a second AMF, a request to create an SM context for a second requested PDU session for dual steering, the request to create the SM context for the second requested PDU session comprising a second SUPI, a second PDU session identifier, and a DS session identifier. The method further comprises obtaining a first SUPI associated to the second SUPI for dual steering, obtaining an SMF identity of a first SMF based on the first SUPI and the DS session identifier, and sending, to the second AMF, a request for redirection of the second AMF to the first SMF, the request for redirection comprising the SMF identity of the first SMF.

[0082] In one embodiment, the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

[0083] Corresponding embodiments of a second SMF are also disclosed.Brief Description of the Drawings

[0084] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0085] Figure 1 illustrates the architecture for Access Traffic Steering, Switching, and Splitting (ATSSS) for the non-roaming case as defined in 3rd Generation Partnership Project (3GPP) Technical Specification (TS) 23.501;

[0086] Figure 2 illustrates one example of a system in which embodiments of the present disclosure may be implemented;

[0087] Figures 3 A and 3B illustrate an example embodiment of a procedure for a Dual Steering (DS) connection in accordance with a first alternative of Solution 1 (i.e., Solutionl- Alt.l) of the present disclosure;

[0088] Figures 4A and 4B illustrate an example embodiment of a procedure for a DS connection in accordance with a second alternative of Solution 1 (i.e., Solution l-Alt.2) of the present disclosure;

[0089] Figures 5A and 5B illustrate an example embodiment of a procedure for a DS connection in accordance with a first alternative of Solution 2 (i.e., Solution 2-Alt.l) of the present disclosure;

[0090] Figures 6A and 6B illustrate an example embodiment of a procedure for a DS connection in accordance with a second alternative of Solution 2 (i.e., Solution2-Alt.2) of the present disclosure;

[0091] Figure 7 is a schematic block diagram of a network node according to some embodiments of the present disclosure;

[0092] Figure 8 is a schematic block diagram that illustrates a virtualized embodiment of the network node according to some embodiments of the present disclosure;

[0093] Figure 9 is a schematic block diagram of the network node according to some other embodiments of the present disclosure;

[0094] Figure 10 is a schematic block diagram of a User Equipment (UE) according to some embodiments of the present disclosure; and

[0095] Figure 11 is a schematic block diagram of a UE according to some other embodiments of the present disclosure.Detailed Description

[0096] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments.Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0097] Radio Access Node: As used herein, a “radio access node” or “radio network node” or “radio access network node” or “RAN node” is any node in a Radio Access Network (RAN) of a cellular communications network that operates to wirelessly transmit and / or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3 GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), a relay node, a network nodethat implements part of the functionality of a base station (e.g., a network node that implements a gNB Central Unit (gNB-CU) or a network node that implements a gNB Distributed Unit (gNB- DU)) or a network node that implements part of the functionality of some other type of radio access node.

[0098] Core Network Node: As used herein, a “core network node” is any type of node in a core network or any node that implements a core network function. Some examples of a core network node include, e.g., an Access and Mobility Management Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), or the like.

[0099] User Equipment (UE): As used herein, a UE is a wireless communication device, which may be any type of wireless device that has access to (i.e., is served by) a wireless network (e.g., a cellular network). Some examples of a UE include, but are not limited to: a UE in a 3GPP network, a Machine Type Communication (MTC) device, and an Internet of Things (loT) device. Such UEs may be, or may be integrated into, a device such as, e.g., a mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or Personal Computer (PC).

[0100] Network Node: As used herein, a “network node” is a general term that refers to either a radio access node or a core network node.

[0101] Note that the description given herein focuses on a 3 GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system.

[0102] There currently exist certain challenge(s) with respect to a Dual Steering (DS) in a 3GPP system. Currently there are dual-Subscriber Identity Module (SIM) devices on the market that can connect through two 3GPP accesses via two Subscription Permanent Identifiers (SUPIs). 3GPP Service and Systems Aspects subgroup 2 (SA2) has also done enhancements to support such devices in the Multiple Universal SIM (MUSIM) work item. However, it is assumed that each SUPESIM is used to access a specific service / operator, and there is no support for aggregating traffic over the two 3GPP accesses or switching traffic between them. This is what is to be studied in the new 3GPP SA2 study. The challenges are:1. How to establish Protocol Data Unit (PDU) sessions towards a PDU session anchor (PSA) using two 3GPP accesses with two different SUPIs is an issue that needs to be resolved.2. As mentioned, the two SUPIs can be handled by two UEs in the DualSteer device. These two UEs may not be able to generate a common PDU session identifier (ID) and this can be challenging in establishing a PDU session towards the common anchor UPF.3. Considering both SUPIs are connected to the same subscriber, how to handle the policy for the PDU session is also an issue that needs to be resolved.

[0103] Certain aspects of the present disclosure and their embodiments may provide solutions to the aforementioned or other challenges. In this regard, Figure 2 illustrates one example of a system 200 in which embodiments of the present disclosure may be implemented. More specifically, the system 200 of Figure 2 provides an architecture for Dual Steering (DS) from a Home Public Land Mobile Network (HPLMN). As illustrated, the system 200 includes a Dual Steer device 202 including one or more UEs 204 (denoted herein as “UE(s)”). Note that, in one example embodiment, the Dual Steer device 202 includes a single UE 204 having two SUPIs, or a single UE 204 having two SUPIs may form the DualSteer device 202 (i.e., the single UE 204 is the DualSteer device 202). In another embodiment, the DualSteer device 202 includes two UEs 204 each having an associated SUPI.

[0104] As illustrated, in this example, the UE(s) 204 may include any one or more of the following functionalities:• a Multi-Path Transmission Control Protocol (TCP) Protocol (MPTCP) functionality 206 that applies the MPTCP protocol (IETF RFC 8684) and the provisioned ATSSS rules for performing access traffic steering, switching, and splitting.• a Multi-Path Quick User Datagram Protocol (UDP) Internet Connection (MPQUIC) functionality 208 that enables steering, switching, and splitting of UDP traffic between the UE(s) 204 and UPF 210, in accordance with the ATSSS policy created by the network.• an ATSSS Lower Layer (ATSSS-LL) functionality 212 is a data switching function, which decides how to steer, switch, and split the uplink traffic across 3 GPP and non- 3GPP accesses, based on the provisioned ATSSS rules and local conditions (e.g. signal loss conditions). The ATSSS-LL functionality in the UE may be applied to steer, switch and split all types of traffic, including TCP traffic, UDP traffic, Ethernet traffic, etc.• a Performance Measurement Functionality (PMF) 214 that may be used by the UE(s) 204 to obtain access performance measurements over the user-plane of 3 GPP access(es) and / or over the user-plane of non-3GPP access.

[0105] As illustrated, the system 200 includes a first 3GPP access 216 (also referred to herein as “3GPP access 1” or “RANI”) associated with a first AMF 218 (also referred to herein as “AMF1”) and a second 3GPP access 220 (also referred to herein as “3GPP access 2” or “RAN2”)associated with a second AMF 222 (also referred to herein as “AMF2”). The system 200 also includes the UPF 210, an SMF 224 and a PCF 226. As illustrated in Figure 2, in this example, the UPF 210 may include an MPTCP proxy functionality 228, an MPQUIC proxy functionality 230, an ATSSS-LL functionality 232, and a PMF 234.

[0106] For the example embodiments described herein, it is assumed that the UE(s) 204 in the DualSteer device 202 registers to the first 3GPP access 216 (RANI) (and the first AMF 218 (AMF1)) using a first SUPI (SUPI1) and registers to the second 3GPP access 220 (RAN2) (and the second AMF 222 (AMF2)) using a second SUPI (SUP 12).

[0107] The UE(s) 204 in the DualSteer device 202 sends two PDU session establishment requests through two accesses (i.e., the first 3GPP access 216 and the second 3GPP access 220) using different SUPIs (i.e., the first PDU session establishment request with SUPI1 through the first 3GPP access 216 and then the second PDU session establishment request with SUPI2 through the second 3GPP access 220). Both of the PDU session establishment requests contain a (new) flag, referred to herein by the exemplary name “DS PDU indicator”, in the request to indicate that this request is to establish a DS PDU session.

[0108] To handle decisions for policy making, the SMF 224 provides a DS Primary SUPI (e.g., either SUPI1 or SUPI2) to the PCF 226 for all requests related to these PDU Sessions of SUPI1 or SUP 12. In one embodiment, the DS primary SUPI is a new data field in Group data accessible with a DS Group ID, as described below.

[0109] When the Dual Steer device 202 (or more specifically the UE(s) 204) requests the first PDU Session (using SUPI1), the first AMF 218 (AMF1) selects an SMF (i.e., SMF 224) for the first PDU Session.

[0110] To enable the second AMF 222 (AMF2) to choose the same SMF 224 when the UE(s) 204 requests the second PDU Session (using SUPI2), two solutions are disclosed herein and are described below as “Solution 1” and “Solution 2” and related alternatives.

[0111] Solution 1 - UE Context Registration: In Solution 1, upon receiving the first PDU Session Establishment request from the DualSteer device 202 (i.e. for SUPI1):1. The SMF 224 retrieves SUPI2 from a UDM using a new Group ID, referred to herein by the exemplary name “DS Group ID”, in the subscription data that points to SUPI1 and SUPI2.2. The SMF 224 registers an associated SMF UE PDU Session context in the UDM for both SUPI1 and SUPI2. In one embodiment, there is a separate registration for each SUPI (i.e., one registration for SUPI1 and another registration for SUPI2).3. Then, upon receiving the second PDU Session Establishment request from the DualSteer device 202 (i.e., for SUPI2), the second AMF 222 (AMF2) retrieves the SMF UE contextfrom the UDM and uses it to find the SMF 224. Note that the UE context is provided from the UDM to the second AMF 222 when the DualSteer device 202 (i.e., the UE(s) 204) registers to the second 3GPP access 220 with SUPI2.

[0112] Solution 2: SMF redirection: In Solution 2, upon receiving the second PDU Session Establishment request from the DualSteer device 202 (i.e., for SUP 12):1. The second AMF 222 (AMF2) selects a new SMF, SMF2.2. SMF2 retrieves SUPI1 from the UDM using a new Group ID, referred to herein by the exemplary name “DS Group ID”, in the subscription data that points to SUPI1 and SUPI2.3. SMF2 retrieves SMF1 ID (i.e., an identifier of the SMF 224) from the UDM using SUPI1 and the PDU session ID.4. SMF2 sends a redirect request to the second AMF 222 (AMF2) with SMF1 ID.5. The second AMF 222 (AMF2) selects the SMF 224 (SMF1).

[0113] In both Solution 1 and Solution 2, it is assumed that the DualSteer device 202 provides the same PDU Session ID for both PDU Sessions with different SUPIs. However, in some embodiments, the Dual Steer device 202 may not be able to provide the same PDU session ID for both PDU sessions with different SUPIs. For example, in case there are two UEs 204 in the DualSteer device 202, or two 3GPP modems in a single UE 204, the two UEs 204 or two 3GPP modems may not be able to coordinate the selection of a PDU Session ID. Therefore, alternative solutions (Alternative 2) are also described below for both Solution 1 and Solution 2 where the UE(s) 204 in the Dual Steer device 202 may generate different / independent PDU Session IDs for the two SUPIs but, in this case, the UE(s) 204 also includes, in both PDU Session Establishment requests, a common new parameter (referred to herein by the exemplary name “DS Session ID”), which is added to the Non-Access Stratum (NAS) message and will be received by the SMF 224. In this case, in step 2 above for Solution 1, the SMF 224 provides the DS Session ID to a new field, DS Session ID(s), when registering the PDU Session context of SUPI2 in the UDM, and it may use a special / reserved value for PDU Session ID (which is not possible to be selected by the UEs). In step 3 above for Solution 1, the second AMF 222 (AMF2) uses the DS Session ID to find the SMF 224. Furthermore, for Solution2, in step 3, SMF2 uses the DS PDU ID instead of the PDU session ID to retrieve the SMF1 ID.

[0114] Embodiments of the present disclosure provide a new method and signaling to establish a connection to a data network (DN) with two 3GPP accesses and two SUPIs.

[0115] Embodiments of the present disclosure involve new parameters in the UE subscription data, namely, DS Session ID, DS Group ID, DS Primary SUPI.

[0116] Embodiments of the present disclosure involve new parameters in the group subscription data, namely, DS Group ID, DS Primary SUPI.

[0117] Embodiments of the present disclosure involve a new method and signaling to handle policy decisions for connections with two SUPIs connected to the same Subscription Profile.

[0118] Certain embodiments may provide one or more of the following technical advantage(s). Embodiments of the proposed solutions handle connection from a UE(s) in a DualSteer device to the DN using two 3GPP accesses. Embodiments of the present disclosure may use a simple architecture including a single UPF (as PSA) and single SMF which make the task of PDU session establishment easier to handle. This also has no impact on PCF since the SMF sends the DS primary SUPI to the PCF for policy making. Embodiments of the present disclosure have minimal impact to the AMF.

[0119] Now, a more detailed description of the different alternatives of Solution 1 and Solution 2 will be provided in the following subsections.Solution 1 -Alt.1: UE Context Registration with Common PDU Session ID

[0120] Figures 3 A and 3B illustrate an example embodiment of a procedure for a DS connection in accordance with a first alternative of Solution 1 (i.e., Solutionl-Alt. l). In Solution 1-Alt.1, it is assumed that the UE(s) 204 can transmit the same PDU session ID for both SUPIs. The steps of the procedure of Figure 3A and 3B are as follows:

[0121] Step 1 : The UE 204 (i.e., the UE 204 in the case the DualSteer device 202 has a single UE 204, e.g., with two 3GPP modems or a first UE 204 (with SUPI1) in the case where the DualSteer device 202 has two UEs 204) registers to the 5G core (5GC) through the first AMF 218 (AMF1). This step is, for example, the same as described in current 3GPP specifications (see, e.g., 3GPP TS 23.502 V18.3.0, Figure 4.3.2.2.1-1).

[0122] Step 2: UE 204 sends PDU session establishment request of type initial request, using SUPI 1, to the first AMF 218 via the first 3GPP access 216. The UE 204 includes in the N1 SM container a new flag, DS PDU Indicator, which indicates that this PDU session is used for Dual Steering.

[0123] Step 3-4: Same as in current 3GPP specifications (see, e.g., 3GPP TS 23.502 vl8.3.0, Figure 4.3.2.2.1-1). More specifically, the first AMF 218 performs SMF selection whereby the SMF 224 is selected and sends an Nsmf_PDUSession_CreateSMContext request to the SMF 224. This request includes the DS PDU indicator within the N1 SM container.

[0124] Steps 5a and 5b: The SMF 224 retrieves the subscription data of the UE 204 from a first UDM 300, where the retrieved subscription data includes a new internal Group ID, DS Group ID, which identifies a group that includes SUPI1 and SUPI2. The retrieved subscriptiondata also includes the group data DS primary SUPI, which can be either SUPI1 or SUPI2. Thus, the SMF 224 obtains SUPI1, SUPI2, and DS primary SUPI from the first UDM 300. The DS primary SUPI is used in policy decision and / or charging.

[0125] Step 6: The SMF 224 may perform Session Management (SM) Policy Association Establishment as described in current 3GPP specifications (see, e.g., 3GPP TS 23.502, Figure4.3.2.2.1-1 Step 7b) using the DS Primary SUPI.

[0126] Step 7: Same as in current 3GPP specifications (see, e.g., 3GPP TS 23.502, Figure4.3.2.2.1-1).

[0127] Step 8: The SMF 224 registers with the first UDM 300 the same as in current 3GPP specifications (see, e.g., 3GPP TS 23.502, Figure 4.3.2.2.1-1 step 16c).

[0128] Step 9: The SMF 224 also registers with a second UDM 302 using SUPI2 and the PDU session ID.

[0129] Step 10: If the DualSteer device 202 is not already registered with SUPI2 through the second 3 GPP access 220, it does it in this step.

[0130] Step 11 : The UE 204 (i.e., the UE 204 in the case the DualSteer device 202 has a single UE 204, e.g., with two 3 GPP modems or a second UE 204 (with SUPI2) in the case where the DualSteer device 202 has two UEs 204) in the DualSteer device 202 sends a PDU Session Establishment Request (with SUPI2) to the second AMF 222 via the second 3GPP access 220. This step is the same as step 2 but with PDU session request type set to Existing PDU. The UE 204 in the DualSteer device 202 sends the same PDU session ID in the PDU Session Establishment request message.

[0131] Step 12. The second AMF 222 (AMF2) chooses the same SMF 224 for PDU session establishment (based on the PDU session ID using, e.g., the same mechanisms as in current 3 GPP specifications).

[0132] Step 13-15. The same as steps 4-8. More specifically, the second AMF 222 sends an Nsmf_PDUSession_CreateSMContext request to the SMF 224 (step 13). This request includes the DS PDU indicator within the N1 SM container. The SMF 224 retrieves the subscription data of the UE 204 from the first UDM 302, where the retrieved subscription data includes the new internal Group ID, DS Group ID, which identifies the group that includes SUPI1 and SUPI2 (steps 14a and 14b). The retrieved subscription data also includes the group data DS primary SUPI, which can be either SUPI1 or SUPI2. Thus, the SMF 224 obtains SUPI1, SUP 12, and DS primary SUPI from the second UDM 302. The DS primary SUPI is used in policy decision and / or charging. The SMF 224 may perform SM Policy Association Establishment as described in current 3GPP specifications (see, e.g., 3GPP TS 23.502, Figure 4.3.2.2.1-1 Step 7b) using the DS Primary SUPI (step 15).

[0133] Step 16: The SMF 224 performs N4 session modification procedure to accommodate the traffic from the second 3GPP access 220.Solutionl-Alt.2: UE context registration without common PDU Session ID

[0134] Figures 4A and 4B illustrate an example embodiment of a procedure for a DS connection in accordance with a second alternative of Solution 1 (i.e., Solutionl-Alt.2). In Solution l-Alt.2, it is assumed that the UE(s) in the DualSteer device 202 cannot transmit the same PDU session ID for both SUPIs, and the Dual Steer device 202 sends two independent PDU session IDs. However, it is assumed that the Dual Steer device 202 can include the same new ID, DS Session ID, in both PDU session establishment requests. The steps of the procedure of Figures 4A and 4B the same as those of Figures 3 A and 3B except for the following:• In Steps 2, 4, 11, 13, a new parameter DS Session ID is transmitted with the request. Here, there is no need for DS PDU indicator.• In Step 9, the SMF 224 registers the PDU session with SUPI2 and DS Session ID, which is a new parameter in the UE context in SMF data in subscription information. As a required input, the SMF 224 uses a reserved PDU Session ID which is not possible to be selected by the UEs.• In Step 12, the second AMF 222 (AMF2) selects the SMF 224 based on the DS Session ID instead of PDU session ID.Solution 2- Altl: SMF redirecting with common PDU session ID

[0135] Figures 5A and 5B illustrate an example embodiment of a procedure for a DS connection in accordance with a first alternative of Solution 2 (i.e., Solution 2-Alt.l). In Solution 2 -Alt.1, it is assumed that the UE(s) 204 can transmit the same PDU session ID for both SUPIs. The steps of the procedure of Figure 5 A and 5B are as follows:

[0136] Steps 1 to 10: Steps 1-10 are the same as steps 1-8, 10, and 11 of Figures 3 A and 3B described above. Note, however, that step 9 of Figure 3 A is not included in the procedure of Figures 5 A and 5B.

[0137] Step 11 : The AMF1 selects an SMF, which in this example is a second SMF 500 (SMF2).

[0138] Steps 12-13: These steps are the same as steps 13 and 14 in Figure 3B but where the interactions are with the second SMF 500, rather than the first SMF 224.

[0139] Steps 14 and 14b: The second SMF 500 uses SUPH to get the list of PDU Sessions for that SUPH. Then, using the PDU Session ID from the request of step 12, the second SMF 500 obtains the SMF ID of SMF1 from the list.

[0140] Step 15: The second SMF 500 sends, to the second AMF 222, a request for redirection of the second AMF 222 AMF to the first SMF 224. This request includes the SMF1 ID (i.e., the SMF ID of the first SMF 224).

[0141] Steps 16-19: These steps are the same as Steps 13 to 16 in Figure 3B.Solution 2- Alt2: SMF redirecting without common PDU session ID

[0142] Figures 6A and 6B illustrate an example embodiment of a procedure for a DS connection in accordance with a second alternative of Solution 2 (i.e., Solution2-Alt.2). In Solution 2-Alt.2, it is assumed that the UE(s) in the DualSteer device 202 cannot transmit the same PDU session ID for both SUPIs, and the Dual Steer device 202 sends two independent PDU session IDs. However, it is assumed that the Dual Steer device 202 can include the same new ID, DS Session ID, in both PDU session establishment requests. The steps of the procedure of Figures 6 A and 6B are as follows:

[0143] Steps 1 to 10: These steps are the same as steps 1-8, 10, and 11 of Figures 4A and 4B, except that, in step 8, the DS Session ID is also included in in registration of SUPI1 and PDU ID1. The DS Session ID is later used in steps 14a and 14b to obtain the SMF ID of the first SMF 224 (SMF1) Note that step 9 of Figure 4A is not included in the procedure of Figures 6A and 6B.

[0144] Step 11 : The first AMF 218 (AMF1) selects a SMF, which in this example is the second SMF 500 (SMF2).

[0145] Step 12-13: These steps are the same as steps 13 and 14 of Figure 4B but involving the second SMF 500 rather than the first SMF 224.

[0146] Steps 14a and 14b: The second SMF 500 uses SUPI1 to get the list of SMFs that are serving SUPI1 and then uses the DS Session ID from the request of step 12 to obtain the SMF ID of the first SMF 224 (SMF1).

[0147] Step 15: The second SMF 500 sends, to the second AMF 222, a request for redirection of the second AMF 500 to the first SMF 224 (SMF1). This request includes the SMF ID of the first SMF 224 (i.e., SMF1 ID).

[0148] Steps 16-19: These steps are the same as Steps 13 to 16 of Figure 4B.Further Description

[0149] Figure 7 is a schematic block diagram of a network node 700 according to some embodiments of the present disclosure. Optional features are represented by dashed boxes. The network node 700 may be, for example, a core network node that implements a NF (e.g., AMF, SMF, UPF, PCF, UDM, or the like) or a network node that implements all or part of thefunctionality of an NF (e.g., all or part of the functionality of the AMF, SMF, UPF, PCF, UDM, or the like ), as described herein. As illustrated, the network node 700 includes a one or more processors 704 (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), and / or the like), memory 706, and a network interface 708. The one or more processors 704 are also referred to herein as processing circuitry. The one or more processors 704 operate to provide one or more functions of the network node 700 as described herein (e.g., one or more functions of an AMF, SMF, UPF, PCF, UDM, or the like described herein). In some embodiments, the function(s) are implemented in software that is stored, e.g., in the memory 706 and executed by the one or more processors 704.

[0150] Figure 8 is a schematic block diagram that illustrates a virtualized embodiment of the network node 700 according to some embodiments of the present disclosure. Again, optional features are represented by dashed boxes. As used herein, a “virtualized” network node is an implementation of the network node 700 in which at least a portion of the functionality of the network node 700 is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the network node 700 includes one or more processing nodes 800 coupled to or included as part of a network(s) 802. Each processing node 800 includes one or more processors 804 (e.g., CPUs, ASICs, FPGAs, and / or the like), memory 806, and a network interface 808. In this example, functions 810 of the network node 700 described herein (e.g., one or more functions of an AMF, SMF, UPF, PCF, UDM, or the like described herein) are implemented at the one or more processing nodes 800 or distributed across the two or more processing nodes 800 in any desired manner. In some particular embodiments, some or all of the functions 810 of the network node 700 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 800.

[0151] In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the network node 700 or a node (e.g., a processing node 800) implementing one or more of the functions 810 of the network node 700 in a virtual environment according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

[0152] Figure 9 is a schematic block diagram of the network node 700 according to some other embodiments of the present disclosure. The network node 700 includes one or more modules 900, each of which is implemented in software. The module(s) 900 provides thefunctionality of the network node 700 described herein. This discussion is equally applicable to the processing node 800 of Figure 8 where the modules 900 may be implemented at one of the processing nodes 800 or distributed across multiple processing nodes 800.

[0153] Figure 10 is a schematic block diagram of a UE 1000 according to some embodiments of the present disclosure. As illustrated, the UE 1000 includes one or more processors 1002 (e.g., CPUs, ASICs, FPGAs, and / or the like), memory 1004, and one or more transceivers 1006 each including one or more transmitters 1008 and one or more receivers 1010 coupled to one or more antennas 1012. The transceiver(s) 1006 includes radio-front end circuitry connected to the antenna(s) 1012 that is configured to condition signals communicated between the antenna(s) 1012 and the processor(s) 1002, as will be appreciated by on of ordinary skill in the art. The processors 1002 are also referred to herein as processing circuitry. The transceivers 1006 are also referred to herein as radio circuitry. In some embodiments, the functionality of the UE 1000 described above may be fully or partially implemented in software that is, e.g., stored in the memory 1004 and executed by the processor(s) 1002. Note that the UE 1000 may include additional components not illustrated in Figure 10 such as, e.g., one or more user interface components (e.g., an input / output interface including a display, buttons, a touch screen, a microphone, a speaker(s), and / or the like and / or any other components for allowing input of information into the UE 1000 and / or allowing output of information from the UE 1000), a power supply (e.g., a battery and associated power circuitry), etc.

[0154] In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the UE 1000 according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

[0155] Figure 11 is a schematic block diagram of the UE 1000 according to some other embodiments of the present disclosure. The UE 1000 includes one or more modules 1100, each of which is implemented in software. The module(s) 1100 provide the functionality of the UE 1000 described herein.

[0156] Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitrymay be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and / or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according to one or more embodiments of the present disclosure.

[0157] While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.).

[0158] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

Claims1. A method performed in a core network of a wireless communication system for supporting dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following:• at a first Access and Mobility Management Function, AMF, (218): o receiving (Fig. 3 A, step 2), via the first access network, a Protocol Data Unit, PDU, session establishment request from a device (202; 204) for a first subscription permanent identifier, SUPI, wherein the PDU session establishment request comprises the first SUPI, a PDU session identifier, and a dual steering, DS, indicator that indicates that the PDU session establishment request is a request to establish a DS PDU session; o selecting (Fig. 3 A, step 3) a Session Management Function, SMF, (224); o sending (Fig. 3A, step 4), to the SMF (224), a request to create a session management, SM, context for the requested PDU session, the request to create the SM context comprising the first SUPI, the PDU session identifier, and the DS indicator;• at the SMF (224): o receiving (Fig. 3 A, step 4) the request to create the SM context for the requested PDU session; o obtaining (Fig. 3 A, steps 5a and 5b) a second SUPI associated to the first SUPI for dual steering and information that indicates a primary SUPI for the DS PDU session; o sending (Fig. 3A, step 6) the primary SUPI for the DS PDU session to a Policy and Control Function, PCF, (226) for SM policy association; o registering (Fig. 3 A, step 8) with a first Unified Data Management, UDM, using the first SUPI and the PDU session identifier; and o registering (Fig. 3 A, step 9) with a second UDM (which may be the same UDM as the first UDM or a different UDM) using the second SUPI and the PDU session identifier.

2. The method of claim 1, further comprising any one or more of the following:• at a second AMF (222): o receiving (Fig. 3B, step 11), via the second access network, a second PDU session establishment request from the device (202; 204) for the second SUPI, wherein the second PDU session establishment request comprises the second SUPI, thePDU session identifier, and a DS indicator that indicates that the second PDU session establishment request is a request associated to a DS PDU session; o selecting (Fig. 3B, step 12) the SMF (224) based on the PDU session identifier; o sending (Fig. 3B, step 13), to the SMF (224), a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the PDU session identifier, and the DS indicator.

3. The method of claim 2, further comprising any one or more of the following:• at the SMF (224): o receiving (Fig. 3B, step 13) the request to create the SM context for the requested second PDU session; o obtaining (Fig. 3B, steps 14a and 14b) the primary SUPI for the DS PDU session; o sending (Fig. 3B, step 15) the primary SUPI for the DS PDU session to the PCF (226) for SM policy association.

4. The method of any of claims 1 to 3, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

5. A method performed by a device (202) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: sending (Fig. 3 A, step 2) a first Protocol Data Unit, PDU, session establishment request for a first subscription permanent identifier, SUPI, to a first Access and Mobility Management Function, AMF, (218) via the first access network, wherein the first PDU session establishment request comprises the first SUPI, a PDU session identifier, and a dual steering, DS, indicator that indicates that the PDU session establishment request is for a DS PDU session; and sending (Fig. 3B, step 11) a second PDU session establishment request for a second SUPI to a second AMF (222) via the second access network, wherein the second PDU session establishment request comprises the second SUPI, the PDU session identifier, and a DS indicator that indicates that the second PDU session establishment request is for a DS PDU session.

6. The method of claim 5, wherein the first access network is a first 3GPP access network, and the second access network is a second 3 GPP access network.

7. A device adapted to perform the method of claim 5 or 6.

8. The device of claim 7, wherein the device comprises a single User Equipment, UE, associated to both the first SUPI and the second SUPI.

9. The device of claim 7, wherein the device comprises a first User Equipment, UE, associated to the first SUPI and a second UE associated to the second SUPI.

10. A method performed by an Access and Mobility Management Function, AMF, (218) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 3 A, step 2), via the first access network, a Protocol Data Unit, PDU, session establishment request from a device (202; 204) for a first subscription permanent identifier, SUPI, wherein the PDU session establishment request comprises the first SUPI, a PDU session identifier, and a dual steering, DS, indicator that indicates that the PDU session establishment request is for a DS PDU session; selecting (Fig. 3 A, step 3) a Session Management Function, SMF, (224); and sending (Fig. 3 A, step 4), to the SMF (224), a request to create a session management, SM, context for the requested PDU session, the request to create the SM context comprising the first SUPI, the PDU session identifier, and the DS indicator.

11. The method of claim 10, wherein the PDU session identifier is common for the requested PDU session and a second PDU session requested by the device (202; 204) for the DS PDU session via the second access network.

12. The method of claim 10 or 11, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

13. An Access and Mobility Management Function, AMF, (218) adapted to perform the method of any of claims 10 to 12.

14. A method performed by an Access and Mobility Management Function, AMF, (222) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 3B, step 11), via the second access network, a Protocol Data Unit, PDU, session establishment request from a device (202; 204) for a second subscription permanentidentifier, SUPI, wherein the PDU session establishment request comprises the second SUPI, a PDU session identifier, and a dual steering, DS, indicator that indicates that the PDU session establishment request is for a DS PDU session; selecting (Fig. 3B, step 12) a Session Management Function, SMF, (224) based on the PDU session identifier; and sending (Fig. 3B, step 13), to the SMF (224), a request to create a session management, SM, context for the requested PDU session, the request to create the SM context comprising the second SUPI, the PDU session identifier, and the DS indicator.

15. The method of claim 14, wherein the PDU session identifier is common for the requested PDU session and a first PDU session requested by the device (202; 204) for the DS PDU session via the first access network.

16. The method of claim 14 or 15, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

17. An Access and Mobility Management Function, AMF, (222) adapted to perform the method of any of claims 14 to 16.

18. A method performed by a Session Management Function, SMF, (224) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 3 A, step 4) a request to create a session management, SM, context for a first requested Protocol Data Unit, PDU, session for dual steering, the request to create the SM context for the first requested PDU session comprising a first Subscription Permanent Identifier, SUPI, a PDU session identifier, and a dual steering, DS, indicator that indicates that the first requested PDU session is for a DS PDU session; obtaining (Fig. 3 A, steps 5a and 5b) a second SUPI associated to the first SUPI for dual steering and information that indicates a primary SUPI for the DS PDU session; sending (Fig. 3 A, step 6) the primary SUPI for the DS PDU session to a Policy and Control Function, PCF, (226) for SM policy association; registering (Fig. 3 A, step 8) with a first Unified Data Management, UDM, using the first SUPI and the PDU session identifier; and registering (Fig. 3 A, step 9) with a second UDM using the second SUPI and the PDU session identifier.

19. The method of claim 18, further comprising any one or more of the following: receiving (Fig. 3B, step 13) a request to create a SM context for a second requested PDU session for the dual steering, the request to create the SM context for the second requested PDU session comprising the second SUPI, the PDU session identifier, and a DS indicator that indicates that the second requested PDU session is for a DS PDU session; obtaining (Fig. 3B, steps 14a and 14b) the primary SUPI for the DS PDU session; and sending (Fig. 3B, step 15) the primary SUPI for the DS PDU session to the PCF (226) for SM policy association.

20. The method of claim 18 or 19, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

21. A Session Management Function, SMF, (224) adapted to perform the method of any of claims 18 to 20.

22. A method performed in a core network of a wireless communication system for supporting dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following:• at a first Access and Mobility Management Function, AMF, (218): o receiving (Fig. 4A, step 2), via the first access network, a Protocol Data Unit, PDU, session establishment request from a device (202; 204) for a first subscription permanent identifier, SUPI, wherein the PDU session establishment request comprises the first SUPI, a first PDU session identifier, and a dual steering, DS, session identifier; o selecting (Fig. 4A, step 3) a Session Management Function, SMF, (224); o sending (Fig. 4A, step 4), to the SMF (224), a request to create a session management, SM, context for the requested PDU session, the request to create the SM context comprising the first SUPI, the PDU session identifier, and the DS session identifier;• at the SMF (224): o receiving (Fig. 4A, step 4) the request to create the SM context for the requested PDU session; o obtaining (Fig. 4A, steps 5a and 5b) a second SUPI associated to the first SUPI for dual steering and information that indicates a primary SUPI for the DS session;o sending (Fig. 4A, step 6) the primary SUPI for the DS session to a Policy and Control Function, PCF, (226) for SM policy association; o registering (Fig. 4A, step 8) with a first Unified Data Management, UDM, using the first SUPI and the first PDU session identifier; and o registering (Fig. 4A, step 9) with a second UDM using the second SUPI and the DS session identifier.

23. The method of claim 22, further comprising any one or more of the following:• at a second AMF (222): o receiving (Fig. 4B, step 11), via the second access network, a second PDU session establishment request from the device (202; 204) for the second SUPI, wherein the second PDU session establishment request comprises the second SUPI, a second PDU session identifier, and the DS session identifier; o selecting (Fig. 4B, step 12) the SMF (224) based on the DS session identifier; o sending (Fig. 4B, step 13), to the SMF (224), a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the second PDU session identifier, and the DS session identifier.

24. The method of claim 23, further comprising any one or more of the following:• at the SMF (224): o receiving (Fig. 4B, step 13) the request to create the SM context for the requested second PDU session; o obtaining (Fig. 4B, steps 14a and 14b) the primary SUPI for the DS session; o sending (Fig. 4B, step 15) the primary SUPI for the DS session to the PCF (226) for SM policy association.

25. The method of any of claims 22 to 24, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

26. A method performed by a device (202) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: sending (Fig. 4A, step 2) a first Protocol Data Unit, PDU, session establishment request for a first subscription permanent identifier, SUPI, to a first Access and Mobility Management Function, AMF, (218) via the first access network, wherein the first PDU session establishmentrequest comprises the first SUPI, a first PDU session identifier, and a dual steering, DS, session identifier; and sending (Fig. 4B, step 11) a second PDU session establishment request for a second SUPI to a second AMF (222) via the second access network, wherein the second PDU session establishment request comprises the second SUPI, a second PDU session identifier, and the DS session identifier.

27. The method of claim 26, wherein the first access network is a first 3GPP access network, and the second access network is a second 3 GPP access network.

28. A device adapted to perform the method of claim 26 to 27.

29. The device of claim 28, wherein the device comprises a single UE associated to both the first SUPI and the second SUPI.

30. The device of claim 28, wherein the device comprises a first UE associated to the first SUPI and a second UE associated to the second SUPI.

31. A method performed by an Access and Mobility Management Function, AMF, (218) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 4A, step 2), via the first access network, a Protocol Data Unit, PDU, session establishment request from a device (202; 204) for a first subscription permanent identifier, SUPI, wherein the PDU session establishment request comprises the first SUPI, a first PDU session identifier, and a dual steering, DS, session identifier; selecting (Fig. 4A, step 3) a Session Management Function, SMF, (224); and sending (Fig. 4A, step 4), to the SMF (224), a request to create a session management, SM, context for the requested PDU session, the request to create the SM context comprising the first SUPI, the first PDU session identifier, and the DS session identifier.

32. The method of claim 31, wherein the DS session identifier is common for the requested PDU session and a second PDU session requested by the device (202; 204) for the DS session via the second access network.

33. The method of claim 31 or 32, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

34. An Access and Mobility Management Function, AMF, (218) adapted to perform the method of any of claims 31 to 33.

35. A method performed by an Access and Mobility Management Function, AMF, (222) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 4B, step 11), via the second access network, a Protocol Data Unit, PDU, session establishment request from a device (202; 204) for a second subscription permanent identifier, SUPI, wherein the PDU session establishment request comprises the second SUPI, a second PDU session identifier, and a dual steering, DS, session identifier; selecting (Fig. 4B, step 12) a Session Management Function, SMF, (224) based on the DS session identifier; and sending (Fig. 4B, step 13), to the SMF (224), a request to create a session management, SM, context for the requested PDU session, the request to create the SM context comprising the second SUPI, the second PDU session identifier, and the DS session identifier.

36. The method of claim 35, wherein the DS session identifier is common for the requested PDU session and a first PDU session requested by the device (202; 204) for the DS PDU session via the first access network.

37. The method of claim 35 or 36, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

38. An Access and Mobility Management Function, AMF, (222) adapted to perform the method of any of claims 35 to 37.

39. A method performed by a Session Management Function, SMF, (224) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 4A, step 4) a request to create a session management, SM, context for a first requested Protocol Data Unit, PDU, session for dual steering, the request to create the SMcontext for the first requested PDU session comprising a first Subscription Permanent Identifier, SUPI, a first PDU session identifier, and a dual steering, DS, session identifier; obtaining (Fig. 4A, steps 5a and 5b) a second SUPI associated to the first SUPI for dual steering and information that indicates a primary SUPI for the DS session; sending (Fig. 4A, step 6) the primary SUPI for the DS session to a Policy and Control Function, PCF, (226) for SM policy association; registering (Fig. 4A, step 8) with a first Unified Data Management, UDM, using the first SUPI and the first PDU session identifier; and registering (Fig. 4A, step 9) with a second UDM using the second SUPI and the DS session identifier.

40. The method of claim 39, further comprising any one or more of the following: receiving (Fig. 4B, step 13) a request to create a SM context for a second requested PDU session for the dual steering, the request to create the SM context for the second requested PDU session comprising the second SUPI, a second PDU session identifier, and the DS session identifier; obtaining (Fig. 4B, steps 14a and 14b) the primary SUPI for the DS session; and sending (Fig. 4B, step 15) the primary SUPI for the DS session to the PCF (226) for SM policy association.

41. The method of claim 39 or 40, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

42. A Session Management Function, SMF, (224) adapted to perform the method of any of claims 39 to 41.

43. A method performed in a core network of a wireless communication system for supporting dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following:• at a first Access and Mobility Management Function, AMF, (218): o receiving (Fig. 5 A, step 2), via the first access network, a Protocol Data Unit, PDU, session establishment request from a device (202; 204) for a first subscription permanent identifier, SUPI, wherein the PDU session establishment request comprises the first SUPI, a PDU session identifier, and a dual steering,DS, indicator that indicates that the PDU session establishment request is a request to establish a DS PDU session; o selecting (Fig. 5A, step 3) a first Session Management Function, SMF, (224); o sending (Fig. 5A, step 4), to the first SMF (224), a request to create a session management, SM, context for the requested first PDU session, the request to create the SM context comprising the first SUPI, the PDU session identifier, and the DS indicator;• at the first SMF (224): o receiving (Fig. 5 A, step 4) the request to create the SM context for the requested first PDU session; o obtaining (Fig. 5A, steps 5a and 5b) information that indicates a primary SUPI for the DS PDU session; o sending (Fig. 5A, step 6) the primary SUPI for the DS PDU session to a Policy and Control Function, PCF, (226) for SM policy association; o registering (Fig. 5A, step 8) with a first Unified Data Management, UDM, using the first SUPI and the PDU session identifier.

44. The method of claim 43, further comprising any one or more of the following:• at a second AMF (222): o receiving (Fig. 5B, step 10), via the second access network, a second PDU session establishment request from the device (202; 204) for the second SUPI, wherein the second PDU session establishment request comprises the second SUPI, the PDU session identifier, and a DS indicator that indicates that the second PDU session establishment request is a request associated to a DS PDU session; o selecting (Fig. 5B, step 11) a second SMF (500); o sending (Fig. 5B, step 12), to the second SMF (500), a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the PDU session identifier, and the DS indicator.

45. The method of claim 44, further comprising any one or more of the following:• at the second SMF (500): o receiving (Fig. 5B, step 12) the request to create the SM context for the requested second PDU session;o obtaining (Fig. 5B, steps 13a and 13b) the first SUPI associated to the second SUPI for dual steering; o obtaining (Fig. 5, steps 14a and 14b) an SMF identity of the first SMF (224) based on the first SUPI; o sending (Fig. 5B, step 15), to the second AMF (222), a request for redirection of the second AMF (222) to the first SMF (224), the request for redirection comprising the SMF identity of the first SMF (224).

46. The method of claim 45, further comprising:• at the second AMF (222): o receiving (Fig. 5B, step 15) the request for redirection; and o in response to the request for redirection:■ sending (Fig. 5B, step 16), to the first SMF (224), a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the PDU session identifier, and the DS indicator.

47. The method of claim 46, further comprising one or more of the following:• at the first SMF (224): o receiving (Fig. 5B, step 16) the request to create a SM context for the requested second PDU session; o obtaining (Fig. 5B, steps 17a and 17b) the primary SUPI for the DS PDU session; o sending (Fig. 5B, step 18) the primary SUPI for the DS PDU session to the PCF (226) for SM policy association.

48. The method of any of claims 43 to 47, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

49. A method performed by a device (202) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: sending (Fig. 5A, step 2) a first Protocol Data Unit, PDU, session establishment request for a first subscription permanent identifier, SUPI, to a first Access and Mobility Management Function, AMF, (218) via the first access network, wherein the first PDU session establishment request comprises the first SUPI, a PDU session identifier, and a dual steering, DS, indicator that indicates that the PDU session establishment request is for a DS PDU session; andsending (Fig. 5B, step 10) a second PDU session establishment request for a second SUPI to a second AMF (222) via the second access network, wherein the second PDU session establishment request comprises the second SUPI, the PDU session identifier, and a DS indicator that indicates that the second PDU session establishment request is for a DS PDU session.

50. The method of claim 49, wherein the first access network is a first 3GPP access network, and the second access network is a second 3 GPP access network.

51. A device adapted to perform the method of claim 49 or 50.

52. The device of claim 51, wherein the device comprises a single UE associated to both the first SUPI and the second SUPI.

53. The device of claim 51, wherein the device comprises a first UE associated to the first SUPI and a second UE associated to the second SUPI.

54. A method performed by an Access and Mobility Management Function, AMF, (218) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 5 A, step 2), via the first access network, a Protocol Data Unit, PDU, session establishment request from a device (202; 204) for a first subscription permanent identifier, SUPI, wherein the PDU session establishment request comprises the first SUPI, a PDU session identifier, and a dual steering, DS, indicator that indicates that the PDU session establishment request is for a DS PDU session; selecting (Fig. 5A, step 3) a Session Management Function, SMF, (224); and sending (Fig. 5A, step 4), to the SMF (224), a request to create a session management, SM, context for the requested PDU session, the request to create the SM context comprising the first SUPI, the PDU session identifier, and the DS indicator.

55. The method of claim 54, wherein the PDU session identifier is common for the requested PDU session and a second PDU session requested by the device (202; 204) for the DS PDU session via the second access network.

56. The method of claim 54 or 55, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

57. An Access and Mobility Management Function, AMF, (218) adapted to perform the method of any of claims 54 to 56.

58. A method performed by an Access and Mobility Management Function, AMF, (222) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 5B, step 10), via the second access network, a Protocol Data Unit, PDU, session establishment request from a device (202; 204) for a second subscription permanent identifier, SUPI, wherein the PDU session establishment request comprises the second SUPI, a PDU session identifier, and a dual steering, DS, indicator that indicates that the PDU session establishment request is for a DS PDU session; selecting (Fig. 5B, step 11) a second Session Management Function, SMF, (500); sending (Fig. 5B, step 12), to the second SMF (500), a request to create a session management, SM, context for the requested PDU session, the request to create the SM context comprising the second SUPI, the PDU session identifier, and the DS indicator; receiving (Fig. 5B, step 14), from the second SMF (500), a request for redirection of the AMF (222) to a first SMF (224); and in response to the request for redirection, sending (Fig. 5B, step 16), to the first SMF (224), a request to create a SM context for the requested PDU session, the request to create the SM context comprising the second SUPI, the PDU session identifier, and the DS indicator.

59. The method of claim 58, wherein the PDU session identifier is common for the requested PDU session and a first PDU session requested by the device (202; 204) for the DS PDU session via the first access network.

60. The method of claim 58 or 59, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

61. An Access and Mobility Management Function, AMF, (222) adapted to perform the method of any of claims 58 to 60.

62. A method performed by a Session Management Function, SMF, (224) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following:receiving (Fig. 5 A, step 4) a request to create a session management, SM, context for a first requested Protocol Data Unit, PDU, session for dual steering, the request to create the SM context for the first requested PDU session comprising a first Subscription Permanent Identifier, SUPI, a PDU session identifier, and a dual steering, DS, indicator that indicates that the first requested PDU session is for a DS PDU session; obtaining (Fig. 5A, steps 5a and 5b) information that indicates a primary SUPI for the DS PDU session; sending (Fig. 5A, step 6) the primary SUPI for the DS PDU session to a Policy and Control Function, PCF, (226) for SM policy association; registering (Fig. 5A, step 8) with a first Unified Data Management, UDM, using the first SUPI and the PDU session identifier.

63. The method of claim 62, further comprising any one or more of the following: receiving (Fig. 5B, step 16) a request to create a SM context for a second requested PDU session for the dual steering, the request to create the SM context for the second requested PDU session comprising the second SUPI, the PDU session identifier, and a DS indicator that indicates that the second requested PDU session is for a DS PDU session; obtaining (Fig. 5B, steps 17a and 17b) the primary SUPI for the DS PDU session; and sending (Fig. 5B, step 18) the primary SUPI for the DS PDU session to the PCF (226) for SM policy association.

64. The method of claim 62 or 63, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

65. A Session Management Function, SMF, (224) adapted to perform the method of any of claims 62 to 64.

66. A method performed by a second Session Management Function, SMF, (500) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 5B, step 12), from a second AMF (222), a request to create a session management, SM, context for a second requested Protocol Data Unit, PDU, session for dual steering, the request to create the SM context for the second requested PDU session comprising a second Subscription Permanent Identifier, SUPI, a PDU session identifier, and a dual steering, DS, indicator that indicates that the second requested PDU session is for a DS PDU session;obtaining (Fig. 5B, steps 13a and 13b) a first SUPI associated to the second SUPI for dual steering; obtaining (Fig. 5, steps 14a and 14b) an SMF identity of a first SMF (224) based on the first SUPI; sending (Fig. 5B, step 15), to the second AMF (222), a request for redirection of the second AMF (222) to the first SMF (224), the request for redirection comprising the SMF identity of the first SMF (224).

67. The method of claim 66, wherein the first access network is a first 3GPP access network, and the second access network is a second 3 GPP access network.

68. A Session Management Function, SMF, (224) adapted to perform the method of any of claims 66 to 67.

69. A method performed in a core network of a wireless communication system for supporting dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following:• at a first Access and Mobility Management Function, AMF, (218): o receiving (Fig. 6A, step 2), via the first access network, a Protocol Data Unit, PDU, session establishment request from a device (202; 204) for a first subscription permanent identifier, SUPI, wherein the PDU session establishment request comprises the first SUPI, a first PDU session identifier, and a dual steering, DS, session identifier; o selecting (Fig. 6A, step 3) a first Session Management Function, SMF, (224); o sending (Fig. 6A, step 4), to the first SMF (224), a request to create a session management, SM, context for the requested first PDU session, the request to create the SM context comprising the first SUPI, the first PDU session identifier, and the DS session identifier;• at the first SMF (224): o receiving (Fig. 6A, step 4) the request to create the SM context for the requested first PDU session; o obtaining (Fig. 6A, steps 5a and 5b) information that indicates a primary SUPI for the DS session; o sending (Fig. 6A, step 6) the primary SUPI for the DS session to a Policy and Control Function, PCF, (226) for SM policy association;o registering (Fig. 6A, step 8) with a first Unified Data Management, UDM, using the first SUPI, the first PDU session identifier, and optionally the DS Session identifier.

70. The method of claim 69, further comprising any one or more of the following:• at a second AMF (222): o receiving (Fig. 6B, step 10), via the second access network, a second PDU session establishment request from the device (202; 204) for the second SUPI, wherein the second PDU session establishment request comprises the second SUPI, a second PDU session identifier, and the DS session identifier; o selecting (Fig. 6B, step 11) a second SMF (500); o sending (Fig. 6B, step 12), to the second SMF (500), a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the second PDU session identifier, and the DS session identifier.

71. The method of claim 70, further comprising any one or more of the following:• at the second SMF (500): o receiving (Fig. 6B, step 12) the request to create the SM context for the requested second PDU session; o obtaining (Fig. 6B, steps 13a and 13b) the first SUPI associated to the second SUPI for dual steering; o obtaining (Fig. 6B, steps 14a and 14b) an SMF identity of the first SMF (224) based on the first SUPI and the DS session identifier; o sending (Fig. 6B, step 15), to the second AMF (222), a request for redirection of the second AMF (222) to the first SMF (224), the request for redirection comprising the SMF identity of the first SMF (224).

72. The method of claim 71, further comprising:• at the second AMF (222): o receiving (Fig. 6B, step 15) the request for redirection; and o in response to the request for redirection:■ sending (Fig. 6B, step 16), to the first SMF (224), a request to create a SM context for the requested second PDU session, the request to create the SMcontext for the requested second PDU session comprising the second SUPI, the second PDU session identifier, and the DS session identifier.

73. The method of claim 72, further comprising one or more of the following:• at the first SMF (224): o receiving (Fig. 6B, step 16) the request to create a SM context for the requested second PDU session; o obtaining (Fig. 6B, steps 17a and 17b) the primary SUPI for the DS session; o sending (Fig. 6B, step 18) the primary SUPI for the DS session to the PCF (226) for SM policy association.

74. The method of any of claims 69 to 73, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

75. A method performed by a device (202) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: sending (Fig. 6A, step 2) a first Protocol Data Unit, PDU, session establishment request for a first subscription permanent identifier, SUPI, to a first Access and Mobility Management Function, AMF, (218) via the first access network, wherein the first PDU session establishment request comprises the first SUPI, a first PDU session identifier, and a dual steering, DS, session identifier; and sending (Fig. 6B, step 10) a second PDU session establishment request for a second SUPI to a second AMF (222) via the second access network, wherein the second PDU session establishment request comprises the second SUPI, a second PDU session identifier, and the DS session identifier.

76. The method of claim 75, wherein the first access network is a first 3GPP access network, and the second access network is a second 3 GPP access network.

77. A device adapted to perform the method of claim 75 to 76.

78. The device of claim 77, wherein the device comprises a single UE associated to both the first SUPI and the second SUPI.

79. The device of claim 77, wherein the device comprises a first UE associated to the first SUPI and a second UE associated to the second SUPI.

80. A method performed by an Access and Mobility Management Function, AMF, (218) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 6A, step 2), via the first access network, a Protocol Data Unit, PDU, session establishment request from a device (202; 204) for a first subscription permanent identifier, SUPI, wherein the PDU session establishment request comprises the first SUPI, a first PDU session identifier, and a dual steering, DS, session identifier; selecting (Fig. 6A, step 3) a Session Management Function, SMF, (224); and sending (Fig. 6A, step 4), to the SMF (224), a request to create a session management, SM, context for the requested PDU session, the request to create the SM context comprising the first SUPI, the first PDU session identifier, and the DS session identifier.

81. The method of claim 80, wherein the DS session identifier is common for the requested PDU session and a second PDU session requested by the device (202; 204) for the DS session via the second access network.

82. The method of claim 80 or 81, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

83. An Access and Mobility Management Function, AMF, (218) adapted to perform the method of any of claims 80 to 82.

84. A method performed by a second Access and Mobility Management Function, AMF, (222) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 6B, step 10), via the second access network, a Protocol Data Unit, PDU, session establishment request from a device (202; 204) for a second subscription permanent identifier, SUPI, wherein the PDU session establishment request comprises the second SUPI, a second PDU session identifier, and a dual steering, DS, session identifier; selecting (Fig. 6B, step 11) a second Session Management Function, SMF, (500);sending (Fig. 6B, step 12), to the second SMF (224), a request to create a session management, SM, context for the requested PDU session, the request to create the SM context comprising the second SUPI, the second PDU session identifier, and the DS session identifier; receiving (Fig. 6B, step 15), from the second SMF (224), a request for redirection of the second AMF (222) to a first SMF (224), the request for redirection comprising an SMF identity of the first SMF (224); and in response to the request for redirection, sending (Fig. 6B, step 16), to the first SMF (224), a request to create a SM context for the requested second PDU session, the request to create the SM context for the requested second PDU session comprising the second SUPI, the second PDU session identifier, and the DS session identifier.

85. The method of claim 84, wherein the DS session identifier is common for the requested PDU session and a first PDU session requested by the device (202; 204) for the DS session via the first access network.

86. The method of claim 84 or 85, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

87. A second Access and Mobility Management Function, AMF, (500) adapted to perform the method of any of claims 84 to 86.

88. A method performed by a first Session Management Function, SMF, (224) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 6A, step 4) a request to create a session management, SM, context for a first requested Protocol Data Unit, PDU, session for dual steering, the request to create the SM context for the first requested PDU session comprising a first Subscription Permanent Identifier, SUPI, a first PDU session identifier, and a dual steering, DS, session identifier; obtaining (Fig. 6A, steps 5a and 5b) information that indicates a primary SUPI for the DS PDU session; sending (Fig. 6A, step 6) the primary SUPI for the DS session to a Policy and Control Function, PCF, (226) for SM policy association; registering (Fig. 6A, step 8) with a first Unified Data Management, UDM, using the first SUPI, the PDU session identifier, and the DS session identifier.

89. The method of claim 88, further comprising any one or more of the following: receiving (Fig. 6B, step 16) a request to create a SM context for a second requested PDU session for the dual steering, the request to create the SM context for the second requested PDU session comprising the second SUPI, the second PDU session identifier, and the DS session identifier; obtaining (Fig. 6B, steps 17a and 17b) the primary SUPI for the DS session; and sending (Fig. 6B, step 18) the primary SUPI for the DS session to the PCF (226) for SM policy association.

90. The method of claim 88 or 89, wherein the first access network is a first 3GPP access network, and the second access network is a second 3GPP access network.

91. A first Session Management Function, SMF, (224) adapted to perform the method of any of claims 88 to 90.

92. A method performed by a second Session Management Function, SMF, (500) for dual steering of data traffic via a first access network and a second access network, the method comprising any one or more of the following: receiving (Fig. 6B, step 12), from a second AMF (222), a request to create a session management, SM, context for a second requested Protocol Data Unit, PDU, session for dual steering, the request to create the SM context for the second requested PDU session comprising a second Subscription Permanent Identifier, SUPI, a second PDU session identifier, and a dual steering, DS, session identifier; obtaining (Fig. 6B, steps 13a and 13b) a first SUPI associated to the second SUPI for dual steering; obtaining (Fig. 6B, steps 14a and 14b) an SMF identity of a first SMF (224) based on the first SUPI and the DS session identifier; sending (Fig. 6B, step 15), to the second AMF (222), a request for redirection of the second AMF (222) to the first SMF (224), the request for redirection comprising the SMF identity of the first SMF (224).

93. The method of claim 92, wherein the first access network is a first 3GPP access network, and the second access network is a second 3 GPP access network.

94. A Session Management Function, SMF, (224) adapted to perform the method of any of claims 92 to 93.

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