Methods, apparatuses and computer program for dual steering

Abstract

A method comprising: receiving a request for a first data session with an indication that dual steering is required, dual steering being provided by first data session which is associated with a first subscription and uses a first network access to access a network and by a second data session which is associated with a second subscription and uses a second network access to access the network, the request being associated with the first subscription; sending, to a first session management function, a session management message for the first session; and receiving a response from a second session management function for the first data session, said second session management function handling the first and the second data sessions.

Description

[0001] METHODS, APPARATUSES AND COMPUTER PROGRAM FOR DUAL STEERING

[0002] Technical Field

[0003] This disclosure relates to methods, apparatus and computer programs, and in particular - but not exclusively - to methods, apparatus and computer program relating to dual steering.

[0004] Background

[0005] A communication system can be seen as a facility that enables communication sessions between two or more entities such as communication devices, base stations and / or other nodes by providing carriers between the various entities involved in the communications path.

[0006] The communication system and associated entities typically operate in accordance with a given standard or specification which sets out what the associated entities are permitted to do and how that should be achieved. Communication protocols and / or parameters that shall be used for the connection are also typically defined. Examples of standard include the so-called 5G standards.

[0007] Summary

[0008] Some example embodiments of this disclosure will be described with respect to certain aspects. These aspects are not intended to indicate key or essential features of the various example embodiments of this disclosure, nor are they intended to be used to limit the scope of thereof. Other features, aspects, and elements will be readily apparent to a person skilled in the art in view of this disclosure.

[0009] According to a first aspect, there is provided an apparatus comprising: means for receiving a user equipment routing policy comprising dual steering information; and means for ensuring, based on the dual steering information of said user equipment routing policy, that a first data session with a network via a first access network and a second data session with the network via a second access network to provide dual steering are established, the first data session being associated with a first subscription and the second data session being associated with a second subscription.

[0010] The first and second data sessions may comprise first and second packet data unit data sessions. The means for ensuring may be for sending one or more data sessions requests comprising an indication that dual steering is required , a data session request being associated with a respective one or more of the first and second data sessions.

[0011] The apparatus may comprise means for determining from the user equipment routing policy that one or more of the first and second data sessions is able to be requested as a data session supporting dual steering.

[0012] The dual steering information may be provided by a dual steering indicator in a respective route selection descriptor parameter.

[0013] The apparatus may comprise means for determining for an application if the respective route selection descriptor parameter comprises the dual steering indicator for that application.

[0014] The apparatus may comprise means for determining for a respective single network slice selection assistance information and data network name combination if the respective route selection descriptor parameter comprises a dual steering indicator.

[0015] One or more route selection descriptor parameters may be associated with a validity criterion such that the respective route selection descriptor parameter is only valid for a data session supporting dual steering.

[0016] The dual steering information may comprise information about one or more combinations of said first access network and said second access network.

[0017] The dual steering information may comprise information about one or more combinations of said first access network and said second access network preferred for a respective application.

[0018] The dual steering information may comprise information a first indicator associated with the first subscriber indicating for first application traffic if the first data session is to be active or on standby and a second indicator associated with the second subscriber indicating for the first application traffic if the second data session is to be active or on standby.

[0019] The user equipment routing policy may comprise: one or more first rules associated with the first subscriber and received via the first access network, the one or more first rules comprising information about dual steering; and one or more second rules associated with the second subscriber and received via the second access network the one or more second rules comprising information about dual steering. The apparatus may comprise means for combining one or more first rules and one or more second rules to provide one or more rules for dual steering.

[0020] The apparatus may comprise or be a user equipment of the dual steer device.

[0021] The apparatus may be a dual steer device.

[0022] According to a second aspect, there is provided method comprising: receiving a user equipment routing policy comprising dual steering information; and ensuring, based on the dual steering information of said user equipment routing policy, that a first data session with a network via a first access network and a second data session with the network via a second access network to provide dual steering are established, the first data session being associated with a first subscription and the second data session being associated with a second subscription.

[0023] The first and second data sessions may comprise first and second packet data unit data sessions.

[0024] The method may comprise sending one or more data sessions requests comprising an indication that dual steering is required, a data session request being associated with a respective one or more of the first and second data sessions.

[0025] The method may comprise determining from the user equipment routing policy that one or more of the first and second data sessions is able to be requested as a data session supporting dual steering.

[0026] The dual steering information may be provided by a dual steering indicator in a respective route selection descriptor parameter.

[0027] The method may comprise determining for an application if the respective route selection descriptor parameter comprises the dual steering indicator for that application.

[0028] The method may comprise determining for a respective single network slice selection assistance information and data network name combination if the respective route selection descriptor parameter comprises a dual steering indicator.

[0029] One or more route selection descriptor parameters may be associated with a validity criterion such that the respective route selection descriptor parameter is only valid for a data session supporting dual steering.

[0030] The dual steering information may comprise information about one or more combinations of said first access network and said second access network. The dual steering information may comprise information about one or more combinations of said first access network and said second access network preferred for a respective application.

[0031] The dual steering information may comprise information a first indicator associated with the first subscriber indicating for first application traffic if the first data session is to be active or on standby and a second indicator associated with the second subscriber indicating for the first application traffic if the second data session is to be active or on standby.

[0032] The user equipment routing policy may comprise: one or more first rules associated with the first subscriber and received via the first access network, the one or more first rules comprising information about dual steering; and one or more second rules associated with the second subscriber and received via the second access network the one or more second rules comprising information about dual steering.

[0033] The method may comprise combining one or more first rules and one or more second rules to provide one or more rules for dual steering.

[0034] The method may be performed by an apparatus.

[0035] The apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform any of the methods discussed in relation to the second aspect.

[0036] The apparatus may comprise or be a user equipment of the dual steer device.

[0037] The apparatus may be a dual steer device.

[0038] According to a third aspect, there is provided an apparatus comprising: means for receiving a request for a first data session with an indication that dual steering is required in which the first data session is associated with a first subscription and uses a first network access to access a network data session; and means for sending, to a session management function, a message comprising one or more of: an indication that dual steering is required; a subscriber identity associated with the first subscription; a subscriber identity associated with a second subscription associated with the dual steering; and / or information identifying a second data session associated with the dual steering.

[0039] The message may comprise a request to establish the first data session or a request to modify the first data session. The apparatus may comprise means for, prior to sending to the session management function the request to establish or modify the first data session, retrieving from a user data management function, session management function data associated with the second subscription.

[0040] The session management function data may comprise registration data associated with the second subscription, the apparatus may further comprise means for determining from the session management function registration data associated with the second subscription that the second data session is already established with a session management function and selecting the same session management function for the first data session.

[0041] The session management function data may comprise data session management function selection data associated with the second subscription, the apparatus may further comprise means for determining from the session management function selection data associated with the second subscription that the second data session is already established with a session management function and selecting the same session management function for the first data session.

[0042] The apparatus may comprise means for receiving a registration message associated with one of the first and second subscriptions, the registration request comprising information indicating that the respective subscription supports dual steering.

[0043] The registration message may comprise a subscriber identity associated with the respective one of the first and second subscriptions.

[0044] The apparatus may comprise means for providing the information indicating that the respective subscription supports dual steering to a user data management function and receiving from the user data management function, a subscriber identity for the other of the first and second subscriptions.

[0045] The apparatus may comprise means for receiving a set of one or more single network slice selection assistance information and data network name combination applicable for dual steering via the first and second data sessions.

[0046] The apparatus may comprise means for implementing an access and mobility function.

[0047] The apparatus may be an access and mobility function.

[0048] The apparatus may implement an access and mobility function. According to a fourth aspect, there is provided a method comprising: receiving a request for a first data session with an indication that dual steering is required in which the first data session is associated with a first subscription and uses a first network access to access a network data session; and sending, to a session management function, a message comprising one or more of: an indication that dual steering is required; a subscriber identity associated with the first subscription; a subscriber identity associated with a second subscription associated with the dual steering; and / or information identifying a second data session associated with the dual steering.

[0049] The message may comprise a request to establish the first data session or a request to modify the first data session.

[0050] The method may comprise prior to sending to the session management function the request to establish or modify the first data session, retrieving from a user data management function, session management function data associated with the second subscription.

[0051] The session management function data may comprise registration data associated with the second subscription, the method further comprising determining from the session management function registration data associated with the second subscription that the second data session is already established with a session management function and selecting the same session management function for the first data session.

[0052] The session management function data may comprise data session management function selection data associated with the second subscription, the method may further comprise determining from the session management function selection data associated with the second subscription that the second data session is already established with a session management function and selecting the same session management function for the first data session.

[0053] The method may comprise receiving a registration message associated with one of the first and second subscriptions, the registration request comprising information indicating that the respective subscription supports dual steering.

[0054] The registration message may comprise a subscriber identity associated with the respective one of the first and second subscriptions.

[0055] The method may comprise providing the information indicating that the respective subscription supports dual steering to a user data management function and receiving from the user data management function, a subscriber identity for the other of the first and second subscriptions.

[0056] The method may comprise receiving a set of one or more single network slice selection assistance information and data network name combination applicable for dual steering via the first and second data sessions.

[0057] The methods of the fourth aspect may be performed by an apparatus.

[0058] The apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform any of the methods discussed in relation to the fourth aspect.

[0059] The apparatus may implement an access and mobility function.

[0060] According a fifth aspect, there is provided an apparatus comprising: means for receiving from an access and mobility function, a session management message associated with a first data session, said first data session and a second data session together to provide dual steering, said first data session being associated with a first subscription and using a first network access to access a network and the second data session is associated with a second subscription and uses a second network access to access the network, said session management message comprising one or more of: an indication that dual steering is required; a subscriber identity associated with the first subscription; a subscriber identity associated with the second subscription; and / or information identifying the second data session.

[0061] The apparatus may comprise means for linking the first and second data sessions.

[0062] The apparatus may comprise means for selecting a common user plane function for the first and second data sessions.

[0063] The apparatus may comprise means for selecting a common policy control function for the first and second data sessions and providing to the policy control function one or more of: the indication that dual steering is required; the subscriber identity associated with the first subscription; the subscriber identity associated with the second subscription; and / or information identifying the second data session.

[0064] The apparatus may comprise means for receiving from the policy control function one or more dual steering rules or policies and providing the one or more dual steering rules or policies to a dual steer device associated with the first and second subscriptions.

[0065] The apparatus may comprise means for implementing a session management function.

[0066] The apparatus may be a session management function, The apparatus may implement session management function.

[0067] According a sixth aspect, there is provided a method comprising: receiving from an access and mobility function, a session management message associated with a first data session, said first data session and a second data session together to provide dual steering, said first data session being associated with a first subscription and using a first network access to access a network and the second data session is associated with a second subscription and uses a second network access to access the network, said session management message comprising one or more of: an indication that dual steering is required; a subscriber identity associated with the first subscription; a subscriber identity associated with the second subscription; and / or information identifying the second data session.

[0068] The method may comprise linking the first and second data sessions.

[0069] The method may comprise selecting a common user plane function for the first and second data sessions.

[0070] The method may comprise selecting a common policy control function for the first and second data sessions and providing to the policy control function one or more of: the indication that dual steering is required; the subscriber identity associated with the first subscription; the subscriber identity associated with the second subscription; and / or information identifying the second data session.

[0071] The method may comprise receiving from the policy control function one or more dual steering rules or policies and providing the one or more dual steering rules or policies to a dual steer device associated with the first and second subscriptions.

[0072] The methods of the sixth aspect may be performed by an apparatus.

[0073] The apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform any of the methods discussed in relation to the sixth aspect.

[0074] The apparatus may implement a session management function.

[0075] According to an seventh aspect, there is provided an apparatus comprising: means for receiving a request for a first data session with an indication that dual steering is required, dual steering being provided by first data session which is associated with a first subscription and uses a first network access to access a network and by a second data session which is associated with a second subscription and uses a second network access to access the network, the request being associated with the first subscription; means for sending, to a first session management function, a session management message for the first session; and means for receiving a response from a second session management function for the first data session, said second session management function handling the first and the second data sessions.

[0076] The apparatus may comprise means for, prior to receiving the response from the second session management function, receiving from the first session management function information indicating that a session management message for the first data session is to be sent to the second session management function.

[0077] The information received from the first session management function may indicate dual steering as a cause for sending of the session management message to the second session management function.

[0078] The apparatus may comprise means for, prior to receiving the response from the second session management function, sending a session management message associated with the first data session to the second session management function for the first data session.

[0079] The request for the first data session may comprise an indication that dual steering is required.

[0080] The apparatus may comprise means for, prior to receiving the response from the second session management function, receiving a session establishment request message from the second session management function, when the first session establishment request has been forwarded from the first session management function.

[0081] The apparatus may comprise means for implementing an access and mobility function.

[0082] The apparatus may be an access and mobility function,

[0083] The apparatus may implement an access and mobility function.

[0084] According to an eighth aspect, there is provided a method comprising: receiving a request for a first data session with an indication that dual steering is required, dual steering being provided by first data session which is associated with a first subscription and uses a first network access to access a network and by a second data session which is associated with a second subscription and uses a second network access to access the network, the request being associated with the first subscription; sending, to a first session management function, a session management message for the first session; and receiving a response from a second session management function for the first data session, said second session management function handling the first and the second data sessions. The method may comprise, prior to receiving the response from the second session management function, receiving from the first session management function information indicating that a session management message for the first data session is to be sent to the second session management function.

[0085] The information received from the first session management function may indicate dual steering as a cause for sending of the session management message to the second session management function.

[0086] The method may comprise prior to receiving the response from the second session management function, sending a session management message associated with the first data session to the second session management function for the first data session.

[0087] The request for the first data session may comprise an indication that dual steering is required.

[0088] The method may comprise prior to receiving the response from the second session management function, receiving a session establishment request message from the second session management function, when the first session establishment request has been forwarded from the first session management function.

[0089] The methods of the eight aspect may be performed by an apparatus.

[0090] The apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform any of the methods discussed in relation to the eighth aspect.

[0091] The apparatus may implement an access and mobility function.

[0092] According to a ninth aspect, there is provided an apparatus comprising: means for receiving at a first session management function, a session management message, from an access and mobility function, for a first data session with an indication that dual steering is required, dual steering being provided by first data session which is associated with a first subscription and uses a first network access to access a network and by a second data session which is associated with a second subscription and uses a second network access to access the network, the session management message being associated with the first subscription; means for retrieving subscription data associated with the first subscription, said subscription data comprising information indicating a second session management function associated with said second season; and means for determining from said subscription data that the first data session is to be associated with the second management function. The apparatus may comprise means for sending a response to the access and mobility function, indicating that the first data session is to be managed by the second session management function.

[0093] The response may comprise a request to redirect to the second session management function.

[0094] The apparatus may comprise means for implementing a session management function.

[0095] The apparatus may be a session management function,

[0096] The apparatus may implement session management function.

[0097] According to a tenth aspect, there is provided a method comprising: receiving at a first session management function, a session management message, from an access and mobility function, for a first data session with an indication that dual steering is required, dual steering being provided by first data session which is associated with a first subscription and uses a first network access to access a network and by a second data session which is associated with a second subscription and uses a second network access to access the network, the session management message being associated with the first subscription; retrieving subscription data associated with the first subscription, said subscription data comprising information indicating a second session management function associated with said second season; and determining from said subscription data that the first data session is to be associated with the second management function.

[0098] The method may comprise sending a response to the access and mobility function, indicating that the first data session is to be managed by the second session management function.

[0099] The response may comprise a request to redirect to the second session management function.

[0100] The methods of the tenth aspect may be performed by an apparatus.

[0101] The apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform any of the methods discussed in relation to the tenth aspect.

[0102] The apparatus may implement a session management function.

[0103] According to an eleventh aspect, there is provided an apparatus comprising: means for sending to the network a request to establish a first data session with an indication that dual steering is required for the first data session, dual steering being provided by the first data session which is associated with a first subscription and by a second data session which is associated with a second subscription, the request being associated with the first subscription; and means for sending to the network user data associated with dual steering via the first data session.

[0104] The apparatus may comprise means for sending a request to register to the network, the request to register associated with the first subscription, said request to register comprising an indication that dual steering is supported.

[0105] The apparatus may comprise a first user equipment of a dual steer device, the first user equipment being associated with the first subscription.

[0106] The apparatus may be the dual steer device and further comprise a second user equipment, the second user equipment being associated with the second subscription.

[0107] The apparatus may comprise a user equipment of a dual steer device, the first subscription and the second subscription being associated with the user equipment.

[0108] The apparatus may comprise means for sending a request to the network to establish the second data session, said request comprising an indication that dual steering is required for the second data session.

[0109] According to a twelfth aspect, there is provided a method comprising: sending to the network a request to establish a first data session with an indication that dual steering is required for the first data session, dual steering being provided by the first data session which is associated with a first subscription and by a second data session which is associated with a second subscription, the request being associated with the first subscription; and sending to the network user data associated with dual steering via the first data session.

[0110] The method may comprise sending a request to register to the network, the request to register associated with the first subscription, said request to register comprising an indication that dual steering is supported.

[0111] The method may comprise sending a request to the network to establish the second data session, said request comprising an indication that dual steering is required for the second data session.

[0112] The method may comprise sending a request to the network to establish the second data session, said request comprising an indication that dual steering is required for the second data session.

[0113] The method may be performed by an apparatus. The apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform any of the methods discussed in relation to the second aspect.

[0114] The apparatus may comprise or be a user equipment of the dual steer device.

[0115] The apparatus may be a dual steer device.

[0116] According to an aspect, there is provided a computer readable medium comprising program instructions stored thereon for performing at least one of the above methods.

[0117] According to an aspect, there is provided a non-transitory computer readable medium comprising program instructions stored thereon for performing at least one of the above methods.

[0118] According to an aspect, there is provided a non-volatile tangible memory medium comprising program instructions stored thereon for performing at least one of the above methods.

[0119] In the above, many different aspects have been described. It should be appreciated that further aspects may be provided by the combination of any two or more of the aspects described above.

[0120] Various other aspects are also described in the following detailed description and in the attached claims.

[0121] Brief Description of the Figures

[0122] Some example embodiments of this disclosure will now be described, by way of nonlimiting and illustrative example only, with reference to the accompanying Figures in which:

[0123] Fig. 1 shows a schematic representation of a 5G system;

[0124] Fig. 2 shows schematically a first example of a dual steer device and a UPF of a 5GC;

[0125] Fig. 3 shows schematically a second example of a dual steer device and a UPF of a 5GC;

[0126] Fig. 4 shows a schematic representation of an apparatus;

[0127] Fig. 5 schematically shows a first procedure in which a common SMF is used for a PDU session;

[0128] Fig. 6 schematically shows a second procedure in which a common SMF is used for a PDU session; Fig. 7 schematically shows a procedure in UE route selection policy rules with dual steer information are used;

[0129] Fig. 8 shows a first method of some example embodiments:

[0130] Fig. 9 shows a second method of some example embodiments;

[0131] Fig. 10 shows a third method of some example embodiments;

[0132] Fig.l 1 shows a fourth method of some example embodiments;

[0133] Fig. 12 shows a fifth method of some example embodiments; and

[0134] Fig. 13 shows a sixth method of some example embodiments;

[0135] Detailed Description

[0136] In the following, the various example embodiments of this disclosure are explained with reference to communication devices capable of communication via a wireless communication system (e.g., a cellular system or a mobile communication system) serving such communication devices. An example wireless communication system is shown in Fig. 1.

[0137] FIG. 1 shows a schematic representation of a deployment comprising a 5G system (5GS).

[0138] The 5GS may comprise multiple public land mobile networks (PLMNs). Each PLMN may comprise a wireless access network comprising a plurality of 5G (radio) access network (R)AN 3GPP-1 and 3GPP2, a 5G core network (5GC), one or more application functions (AF) and one or more data networks (DN) 210. In the example shown in Fig. 1, a dual steer device 200 / 300 of some example embodiments is connected to the 5GC via two different RANs 3GPP- 1 and 3GPP2. The dual steer devices 200 / 300 of some example embodiments are described in more detail later. However, it should be appreciated that the dual steer device may be connected via one or one or more different access networks to the example RANs shown in Fig. 1.

[0139] Some examples of an access network is a 5G (radio) access network, for example a3GPP RAN. Other examples of access networks may be untrusted or wireline non 3 GPP access to a 3GPP core (N3IWF -Non-3GPP Inter-Working Function or W-AGF- wireline5G access gateway function). In another example, one RAN may correspond to a terrestrial (radio access) network while the other RAN may correspond to a terrestrial (radio access) network. In another example, the two (R)AN may be operated by different operators e.g. different PLMN(s), thus possibly controlled by different AMF(s). A 5G RAN may comprise one or more base stations. Abase station may be an evolved NodeB (eNB) or a gNodeB (gNB). A gNB may comprise distributed units connected to one or more centralized units.

[0140] The 5GC shown in Fig. 1 comprises network functions (NF). The network functions shown in Fig. 1 comprise a unified data repository (UDR), a network exposure function (NEF), a network repository function (NRF), a user data management (UDM) function, a policy control function (PCF), an access and mobility management function (AMF), an authentication server function (AUSF), a session management function (SMF), and a user plane function (UPF) 206. It should be appreciated that more than one of a given type of network function may be provided in the 5GC. It should be appreciated that 5GC shown in Fig. 1 may comprise other network functions (NF).

[0141] Some example embodiments relate to a so-called “ dual steer device”.

[0142] A dual steer device is a device supporting traffic steering, traffic splitting and / or traffic switching, of user data across two access networks. The user data may relate to a user equipment data session. The two access networks may be different access networks. The access networks may be two 3 GPP access networks. For example, in some example embodiments, the two access networks may be two different 3GPP access networks. For example, the two different access networks may be provided by different RANs.

[0143] Traffic steering may steer the traffic to one or other or both of the two access networks. Traffic may be split between both of the two access networks. In another example, the traffic may be directed to only one of the access networks. In another example, the traffic may be switched from one of the two access networks to the other of the two access networks.

[0144] A dual steer device may be associated with a first subscription and a second subscription. The first subscription is associated with a first subscriber identifier and the second subscription is associated with a second subscriber identifier. The first and second subscriber identifiers are different subscriber identifiers. The first and second subscriber identifiers may be unique identifiers which are used to represent the identity of a subscriber in a network . The first and second subscriber identifiers may comprise a SUPI (subscription permanent identifier) or any other suitable subscriber identifier.

[0145] Each of the first and second identifiers may be stored in a respective subscriber identity module SIM. For example, the SIM may be store in a universal SIM (USIM).

[0146] The first and second subscriber identities may be linked to a single subscription profile. When a dual steer device provides dual steering, the dual steer device has a first session with a network associated with the first subscriber identifier and via a first access network and a second session associated with the second subscriber identifier and via a second access network. Traffic such as user data may be sent to the network via the first and second sessions. The traffic may be steered, switched and / or split between the first and second sessions..

[0147] The traffic may, for example, comprise data from an application of the dual steer device.

[0148] The first and second sessions may be packet data unit (PDU) sessions.

[0149] Reference is made to Fig. 2 which shows a first example of a dual steer device 200. The dual steer device 200 in this example comprises a first UE, UE1 and a second UE, UE2. The first UE, UE 1 is associated with the first subscriber identifier, SUPI-land the second UE is associated with a second subscriber identifier, SUPI-2. For example, the first UE, UE1 may have a first SIM, e.g. a USIM, storing the first subscriber identifier, SUPI-1 and the second UE may have a second SIM, e.g. a USIM, storing the second subscriber identifier SUPI-2.

[0150] A so-called dual steer layer 204 is provided. The dual steer layer comprises a controlling function. The dual steer layer may be implemented by computer executable code running on at least one processor. The dual steer layer may be referred to a controller. The dual steer layer may be implemented by an apparatus, such as shown in Fig. 4.

[0151] The first UE, UE 1 has network access via first access network 3GPP1 and the second UE, UE2 has network access via a second access network 3GPP2. The first and second access networks are different.

[0152] The dual steer layer will manage the steering, switching and / or splitting of traffic to one or other or both of the two access networks via the first and second UEs.

[0153] The dual steer device may support, if required, simultaneous data transmission over both of the two access networks.

[0154] The traffic which is managed by the dual steer layer may comprise application traffic from an application 202 or any other suitable traffic.

[0155] In some example embodiments the dual steer device may be provided, for example, within a single housing.

[0156] In other example embodiments, the dual steer device may be implemented as a system. Where the dual steer device is implemented as a system, the dual steer layer part of the system is arranged to communicate with the application, for example, and the first and second UEs. That communication may be wired and / or wireless. Reference is made to Fig. 3 which shows a second example of a dual steer device 300. The dual steer device in this example comprises a one UE 302. The UE 302 is associated with the first subscriber identifier SUPI-2 and the second subscriber identifier SUPI-2. For example, the UE may have a first SIM, e.g. a USIM, storing the first subscriber identifier SUPI- land a second SIM, e.g. a USIM, storing the second subscriber identifier SUPI-2.

[0157] Again a dual steer layer 204 is provided, as discussed in relation to Fig. 2. In some example embodiments, the dual steer layer and the application may be provided within the UE. The dual steer device may be implemented within the UE In other example embodiments, the application and / or the dual steer layer may be outside the UE.

[0158] The UE has a first network access associated with the first subscriber identifier via a first access network 3GPP1 and a second network access associated with the second subscriber identifier via a second access network 3GPP2. The first and second access networks are different.

[0159] Regardless of the implementation of the dual-steer device, the dual steer layer 204 may be provided with one or more rules / policies for controlling the steering, switching and / or splitting of the traffic. The dual steer layer is responsible for steering of UL (uplink) data, that is the data from the dual steer device to the network.

[0160] As shown in both Figs. 2 and 3, a user plane function UPF 206 is provided which responsible for steering DL (downlink) data, that is the data from the network to the dual steer device. The UPF is provided with one or more rules / policies 208 for controlling the steering, switching and / or splitting of the DL traffic.

[0161] The traffic from the dual steer device may be provided by the UPF 206 to a DN 210. The DN 210 may provide traffic to the UPF which is for the dual steer device.

[0162] In some example embodiments, the dual-steer device may support traffic steering, splitting, and / or switching of the user data across two access networks.

[0163] Data anchoring may be provided in the HPLMN (home public land mobile network) or in the SNPN (Standalone Non Public Network). The user data may be for different services or for the same service.

[0164] In some example embodiments, the dual-steer device may aim to minimize service interruption when switching the user data, between the two access networks.

[0165] In some example embodiments, the dual-steer device may support changing one 3 GPP access network to a non-3GPP access network of the same subscription (and vice versa). One or more of the following traffic steering, switching and / or splitting examples may be supported by a dual steer device of some example embodiments: traffic steering, switching and / or splitting between two 3GPP access networks belonging to the same or different PLMN(s) or SNPN. The two 3 GPP access networks may be associated with the same or with different RAT (radio access technology). An example of usage of different kinds of 3GPP access is where one corresponds to a terrestrial access network (TNT) and the other to a non-terrestrial access network; traffic steering , switching and / or splitting between two 3GPP access networks of one PLMN and one PNI-NPN (public network integrated non-public network). The two 3 GPP access networks may be associated with the same or with different RAT (radio access technology); and / or traffic steering, switching and / or splitting across LTEZEPC (long term evolution / evolved packet core) and NR / 5GC (new radio / 5G core), with anchoring in 5GC. In other words one access network may be a 4G access network and the other access network may be a 5G access network.

[0166] As mentioned, a dual steer device may uses two subscriptions / SUPIs sharing one subscription profile from the same operator for accessing two access networks through which steering, switching and / or splitting of user data can be performed. In the following examples, the two access networks are 3 GPP access networks. However, it should be appreciated that the access network may be any other suitable type of access network.

[0167] In some example embodiments, the HPLMN may control the traffic policies / rules that are provided to the dual steer device and the network, for the steering of user data across the two 3 GPP access.

[0168] The two SUPIs associated with the dual steer subscriptions may have independent registrations and thereafter independent PDU session establishment for accessing different services.

[0169] The two SUPIs can be registered: in the same PLMN (home HPLM or visited VPLM) with same or different radio access type (e.g. Terrestrial NR (new radio), NTN NR (non-terrestrial new radio), E-UTRA (evolved UMTS (universal mobile telecommunications system) terrestrial radio access,); in two different PLMNs (HPLMN and VPLMN, or VPLMN 1 and VPLMN2) with same or different radio access type; or a combination of PLMN and PNI-NPN.

[0170] For steering, switching and / or splitting of application traffic between the two 3GPP access registrations of the two SUPIs, the 5GC may have a common anchoring UPF 206 for the PDU sessions of the corresponding SUPIs. Since the steering rules / policies may be dynamically provided by the PCF, both the PDU sessions from the two different SUPIs may be served by the same SMF and the same PCF.

[0171] The NFs that are serving the PDU sessions of the two SUPIs of a dual steer device (e.g. SMF, PCF) may correlate the two PDU sessions from the two SUPIs for a dual steer scenario. This may be to allow, enable, or otherwise facilitate, for example, the rules (e.g., relevant, applicable, and / or necessary rules) to be provided to the UPF and the dual steer device.

[0172] In some example embodiments, the access and mobility (AM) subscription data in the UDM stores linkage information between the two SUPIs of the dual steer device and one or more combination of DNN / S-NSSAI that are allowed for dual steer for the said subscription. The linkage information links the two SUPIs of the dual steer device but may also link the DNN / S-NSSAI that are allowed for dual steer for the said subscription .

[0173] This linkage information can be stored as a part of AM data, and / or SM (session management) data, and / or in any other suitable data structure.

[0174] In some example embodiments, SMF selection subscription data from the UDM may comprise a list of combinations of DNN (data network name) and S-NSSAI (single network slice selection assistance information) applicable for dual steering associated with the two SUPIs. The SMF selection subscription data comprises data which allows a SMF to be selected and is based on the common subscription data. Each combination of DNN / S-NSSAI is applicable for dual steering of traffic between the two SUPIs. A (DNN / S-NSSAI) pair is associated with a SMF.

[0175] The linkage information and / or one or more (DNN / S-NSSAI) pairs that are allowed for dual steer for the said subscription and / or one or more (DNN / S-NSSAI) pairs with the information about the selected SMF (referred to a selected SMF information) may be provided to the AMF. The linkage information and / or one or (DNN / S-NSSAI) pairs that are allowed for dual steer for the said subscription and / or one or more (DNN / S-NSSAI) pairs with the associated selected SMF information may be provided to the AMF during a registration procedure. The UDR will store the linkage information. The set of information to be sent by UDM to AMF requires changes in the structure of data stored in UDR.

[0176] In the following examples, a dual steer device with two UEs is used to illustrate some example embodiments. Such a dual steer device may be as shown in Fig. 2. However, it should be appreciated that the various example embodiments of this disclosure may also be used with a dual steer device having a UE associated with two different subscriber identifiers, such as shown in Fig. 3.

[0177] In the following examples, a first subscriber identifier, SUPI-1 and a second subscriber identifier, SUPI-2 are the two subscriber identifiers associated with the dual steer device. When the AMF receives, for example, a request for the establishment of a PDU session (referred to as a PDU session establishment request) associated with the first subscriber identifier, SUPI- 1, the AMF may check the subscription data associated with the first subscriber identifier, SUPI-1 and ensures the first subscriber identifier, SUPI-lis associated with subscription information for dual steering and the DNN / S-NSSAI in the PDU Session Establishment request is allowed for dual steer. The PDU session establishment request associated with the first subscriber identifier, SUPI-1 may include or be associate with an indication, for example an explicit indication, that dual steering is applicable or requested.

[0178] The AMF may send a request for session management (referred to a session management request) to the same SMF that is serving the PDU session associated with the second subscriber identifier, SUPI-2 for the requested DNN / S-NSSAI. This will be in the case where there is an already existing PDU session associated with the second subscriber identifier SUPI-2 with the same DNN / S-NSSAI combination. In some examples, the AMF receives information or an indication about a SMF to use in the SMF selection subscription data received from the UDM. The information about the SMF serving the PDU Session associated with the second subscriber identifier SUPI-2 for the requested DNN / S-NSSAI combination may be provided by the UDM when the AMF requests SMF selection subscription data for the first subscriber identifier, SUPI-1 or may be retrieved, for example explicitly retrieved, by the AMF from the UDM.

[0179] When the AMF receives the PDU session establishment request associated with the first subscriber identifier, SUPI-1 with a request for dual steering, but subscription data associated with the first subscriber identifier, SUPI-1 does not contain a dual steer device indication or the DNN / S-NSSAI in the PDU Session establishment request is not allowed for Dual Steer, then AMF will not provide (e.g.; refrains from providing) a dual steering service associated with the first subscriber identifier, SUPI-1.

[0180] When the AMF receives PDU session establishment request associated with the first subscriber identifier, SUPI-1, if dual steering is not explicitly requested, then the AMF may or may not send (e.g., refrain from sending) the session management request to the same SMF that is serving the PDU Session associated with the second subscriber identifierSUPI-2 for the requested DNN / S-NSSAI combination, if there is an already existing PDU Session associated with the second subscriber identifier SUPL2 to this DNN / S-NSSAI combination.

[0181] The AMF may select for the first PDU session PDU associated with the first subscriber identifier, SUPI-1, a SMF capable of handling (e.g., configured to handle) the DNN / S-NSSAI combinations of the PDU Sessions applicable for dual steering. The AMF may ensure that when dual steering is to be provided, that a common SMF is used for the PDU session associated with the first subscriber identifier. SUPI-1 as well as the PDU session associated with the second subscriber identifier SUPI-2. The common SMF will support the relevant the DNN / S-NSSAI combinations of the two PDU sessions applicable for dual steering.

[0182] The SMF may select a common PCF capable of handling the DNN / S-NSSAI combinations of the two PDU sessions applicable for dual steering.

[0183] The SMF may select a common UPF capable of handling the DNN / S-NSSAI combinations of the two PDU sessions applicable for dual steering.

[0184] A session management request NAS (non-access stratum) PDU session establishment request from the UE to the SMF (received by the SMF via the AMF) may include dual steer related information. For example, the dual steer related information may comprise one or more of the following: an indication whether dual steer is required; linkage information (for example as previously described); the PDU session ID (identity) associated with the linkage information; and / or the like.

[0185] Alternatively, the indication whether dual steer is required may be provided from the UE to AMF in a NAS MM (mobility) message via a UE NAS transport that carries a NAS SM message PDU Session establishment request, In some examples, the AMF may provide this indication to the SMF. This may be provided separately to the PDU session establishment request. If an indication that dual steer is required is provided, the SMF may determine that the dual steering is preferred for the corresponding session. The SMF may link the two PDU sessions associated with the first and second subscriber identifiers SUPI-1 and SUPI-2 of the dual steer device and select the same UPF for both of the PDU sessions.

[0186] The SMF may select the same SM PCF (PCF for session management) and provide the received dual steer information to the PCF. The received dual steer information may be provided as part of the procedure to establish SM policy (referred to a SM policy association establishment) with the PCF. The SMF may provide the reference of the SM policy of a first PDU Session associated with the first subscriber identifier, SUPI-1 when establishing the second SM policy associated with the second subscriber identifier).

[0187] This PCF may generate, dual steer device related policies / rules for an established PDU session and provide them to the SMF. The SMF may send the corresponding rules (e.g. FAR (forwarding action rule) and / or PDR (packet detection rule) and / or MAR (multi access rules)) to the UPF. The rules may be N4 rules. The SMF may send the dual steer rules / policies to the UE or relevant part (communication capabilities) of the UE.

[0188] In a dual steer scenario, the AMF may select the same PCF for the UE policies for both subscriber identifiers . The AMF may determine, when selecting the PCF for the first subscriber identifier SUPI-lthat the PCF is also able to serve the second subscriber identifier SUPI-2. The PCF may determine the dual steer policies / rules which may be sent to the dual steer device. The PCF may determine a URSP (UE route selection policy) which supports dual steering. The URSP may be sent to the dual steer device. This procedure may happen at registration. At registration the AMF establishes a "UE policy association" with the PCF and the PCF then provides UE policies to the UE via AMF (the UE policies also include URSP).

[0189] It should be appreciated that in some examples, if there is no indication that dual steering is required and / or the SMF does not support dual steering feature and / or the subscription (for example obtained from the UDM) associated with a respective subscriber identifier does not allow dual steering for the given subscriber identifier and DNN / S-NSSAI combination, the SMF establishes the PDU session as a regular PDU session.

[0190] Reference is made to Fig. 5 which shows a procedure in which a common SMF is used for a PDU session associated with the first subscriber identifierSUPI-1 of the dual steer device and for a PDU session associated with the second subscriber identifier SUPI-2 of the dual steer. In example embodiments shown in Fig. 5 a first UE and a second UE is shown for ease of reference. However, it should be appreciated that some example embodiments may be alternatively used with a dual steer device such as shown in Fig. 3 with one UE.. In this latter case, UE 1 should be considered as corresponding to the first subscriber identifier, SUPI-1 and UE 2 should be considered as corresponding to the second subscriber identifier, SUPI-2

[0191] The procedure shown in Fig. 5 is made of a registration part, a PDU session establishment part, and selection of a common UPF and a common PCF by the SMF.

[0192] The registration part of the procedure will now be described.

[0193] As referenced at 1, a registration procedure associated with the first subscriber identifier, SUPI-1 is triggered. The registration procedure provides to an AMF, for example a first AMF, AMF1, an indication that dual steering is supported and the first subscriber identifier, SUPI-1. The indication that dual steering is supported is referred to as a dual steer indication in the following.

[0194] As referenced at 2, the first AMF, AMF1 provides the dual steer indication and the first subscriber identifier, SUPI-1 to the UDM.

[0195] As referenced at 3, the UDM provides to the first AMF, AMF1 the second subscriber identifier SUPI, SUPI-2, associated with the dual steer subscriptions and the list of DNN / S- NSSAI combinations that are applicable / allowed for dual steering.

[0196] As referenced at 4, the first AMF, AMF1 stores the information received from the UDM. The first AMF, AMF1 may store the information as part of the UE context information in the AMF.

[0197] As referenced at 5, the first AMF, AMF1 sends a registration accept message to the dual steer device either to the first UE, UE1 where the dual steer device has two UEs or to the part of the UE handling the first subscriber identifier where the dual steer device has one UE.

[0198] As referenced at 6, a PDU session is established associated with the first subscriber identifier, SUPI-1. The session is established with a SMF and a PCF both of which are capable of supporting dual steering for the dual steering device.

[0199] The registration procedure associated with the second subscriber identifier, SUPI-2 is now described.

[0200] As referenced at 7, a registration procedure associated with the second subscriber identifier, SUPI-2 is triggered. The registration procedure provides to an AMF, for example a second AMF, AMF, a dual steer indication and the second subscriber identifier, SUPI-2. In some examples, the AMF is a different AMF to that serving the first subscriber identifier, SUPI-lduring registration. However, it should be appreciated that the same AMF may serving the first subscriber identifier, SUPI-land the second subscriber identifier, SUPI-2.

[0201] As referenced at 8, the second AMF, AMF2 provides the dual steer indication and the second subscriber identifier, SUPI-2 to the UDM.

[0202] As referenced at 9, the UDM provides to the second AMF, AMF2 the first subscriber identifier, SUPI-1, associated with the dual steer subscriptions and the list of DNN / S-NSSAI combinations that are applicable / allowed for dual steering.

[0203] As referenced at 10, the second AMF, AMF2 stores the information received from the UDM. The second AMF, AMF2 may store the information as part of the UE context information in the AMF.

[0204] As referenced at 11, the second AMF, AMF2 sends a registration accept message to the dual steer device either to the second UE, UE2 where the dual steer device has two UEs or to the part (communication capabilities) of the UE handling the second subscriber identifier where the dual steer device has one UE.

[0205] The PDU session establishment associated with the second subscriber identifier, SUPI- 2 will now be described.

[0206] As referenced at 12, the second UE, UE 2 or the part (communication capabilities) of the UE handling the second subscriber identifier SUPI- 2 sends a PDU session request to the second AM, AMF 2 associated with the second subscriber identifier. In some examples, dual steering is required for the PDU session. The request comprises an indication that dual steering is required, e.g. “dual steer required = YES”. The request may comprise the second subscriber identifier, SUPI-2 .

[0207] A first alternative will now be described. In this first alternative, the AMF logic retrieves the SMF for the linked subscriber identifier SUPI and selects a common SMF.

[0208] If the second UE, UE 2 or the part (communication capabilities) of the UE handling the second subscriber identifier SUPI- 2 shas indicated that dual steer is required, and if the DNN / S-NSSAI requested is allowed for dual steer (according to subscription data received from UDM during registration), the AMF retrieves SMF registration data for SUPI-1 from the UDM.

[0209] Thus, as referenced at 13a, the second AMF, AMF2 sends a request for SMF registration data for the first subscriber identifier, SUPI-1. As referenced at 14a, the UDM sends the SMF registration data to the second AMF, AMF2. This may provide the identity of a SMF which is already serving a PDU session associated with the first subscriber identifier, SUPI-1. for the same (DNN / S-NSSAI)

[0210] If there is an SMF already serving a PDU session associated with the first subscriber identifier, SUPI-1 with the DNN / S-NSSAI combination requested by second UE, UE 2 or the part (communication capabilities) of the UE handling the second subscriber identifier SUPI- 2 s, the AMF selects the same SMF to serve the PDU session request associated with the second subscriber identifierSUPI-2.

[0211] As referenced at 15, the AMF sends a request to create a context, for example, a Nsmf PDUSession CreateSMContext request to the selected SMF. The request may include dual steer related information. The dual steer related information may comprise the dual steer indication, and / or the linked subscriber identifier SUPI, and / or the identity of a PDU session associated with the linked subscriber identifier SUPI.

[0212] A second alternative will now be described. In this second alternative, the UDM provides the SMF with the linked subscriber identifier SUPI and the AMF selects a common SMF.

[0213] As referenced at 13b, the second AMF, AMF2 sends a request for SMF selection subscription data for the second subscriber identifier SUPI-2.

[0214] As referenced at 14b, the UDM identifies that second subscriber identifier SUPI-2 is associated with a dual steer subscription. In the response provided to the AMF the UDM also includes the SMF registration data related to the first subscriber identifier, SUPI-1.

[0215] If second UE, UE 2 or the part (communication capabilities) of the UE handling the second subscriber identifier SUPI- 2 has indicated that dual steer is required, and if the requested DNN / S-NSSAI associated with the second subscriber identifier SUPI-2 is allowed for dual steering (according to subscription data received from UDM during registration), the AMF then performs the following check, The AMF checks from the SMF registration data associated with the first subscriber identifier, SUPI-1 provided by the UDM, if there is already an SMF serving a PDU Session associated with the first subscriber identifier, SUPI-1 to the DNN / S-NSSAI for the session to be associated with the second subscriber identifier. If an SMF is found, then the AMF selects the same SMF to serve the PDU session request associated with the second subscriber identifier, SUPI-2 as used for the session associated with the first subscriber identifier, SUPI-1 ). This is then followed by the part of the procedure referenced at 15 and is as previously discussed.

[0216] The part of the procedure relating to the selection of a common UPF and a common PCF is now described.

[0217] As referenced at 16, based on the dual steer information received from the AMF, the SMF links the two PDU session from the two subscriber identifiers SUPIs of dual steer device and select the same UPF. The SMF also selects the same PCF.

[0218] As referenced at 17, the SMF provides dual steer information received from the AMF or from UDM to the PCF in SM (session management) policy association signaling (e.g.SM policy association establishment). This allows the PCF to generate dual steer policies / rules and provide those dual steer policies / rules to the SMF. The SMF then further sends corresponding N4 policies to the UPF and the dual steer device or respective UE of the dual steer device.

[0219] In another example, the session management (SM) subscription data in the UDM has the DNN / S-NSSAI related SM subscription information of one subscriber identifier (e.g. SUPL1) of a dual steer containing a linkage to the other subscriber identifier (e.g. SUPL2) of the dual steer device together with the DNN / S-NSSAI of that other subscriber identifier for which dual steering of traffic is applicable.

[0220] If a SMF is registered for the other subscriber identifier, the reference of that SMF (e.g. SMF set, SMF instance, UR1 (universal resource indicator) for N11 / N16 services) may also be provided. This may be provided as part of the SM subscription data. N11 is the reference point between AMF and SMF and N16 is the reference point between a V-SMF and a H-SMF (N16 is used for a roaming scenario)

[0221] This linkage information may be provided to the SMF during the PDU session establishment procedure for one subscriber identifier SUPI. The reference to the SMF registered for the other subscriber identifier SUPI may also be provided.

[0222] When a first SMF, SMF-1 receives a PDU Session establishment request associated with the first subscriber identifier, SUPI-1, if a dual steer indication is included, then the SMF- 1 redirects the PDU Session establishment request (for example a Nsmf_PDUSession_CreateSMContext request) to a second SMF, SMF-2 that is serving the PDU Session associated with the second subscriber identifier SUPL2 for the requested DNN / S- NSSAI , if there is an already existing PDU Session from SUPL2 to this DNN / S-NSSAI. Redirection may be provided even if the second SMF, SMF-2 is initially selected, too. If AMF has selected a SMF SMF-2 which is not handling (e.g., not configured to handle) the DNN / S-NSSAI associated with the first subscriber identifier, SUPI-1, the initially selected SMF-2 might redirect to another SMF which is able (e.g., configured) to handle the PDU sessions of both subscriber identifiers SUPI-1, SUPI-2.

[0223] No UE SM context is established in the first SMF, SMF-1. The PDU Session establishment request is redirected to the second SMF, SMF-2. The information about the second SMF, SMF-2 that is serving the PDU session associated with the second subscriber identifier SUPI-2 for the requested DNN / S-NSSAI may be retrieved by the SMF from the UDM.

[0224] In another example, information about the second SMF, SMF-2 that is serving the PDU session of associated with the second subscriber identifier SUPI-2 for the requested DNN / S- NSSAI may be provided by the UDM when the SMF requests SM subscription data for the first subscriber identifier, SUPI-1.

[0225] The redirection of the session management request to the second SMF, SMF-2, can be performed by the first SMF, SMF-1 by sending a request for redirection to the AMF. This may be a HTTPS (hypertext transfer protocol secure) REDIRECT request, for example. This case may happen when the AMF does not support dual steer and has selected the second SMF, SMF- 2, because it has been unable to get dual steer related information from the UDM.

[0226] In another example, redirection of the session management request to the second SMF, SMF-2 can be performed by the first SMF, SMF-1, by sending a Nsmf PDUSession CreateSMContext response or other message to the AMF. The response or other message may comprise information identifying the second SMF, SMF-2. The response or other message may comprise information requesting the AMF to forward the PDU Session establishment request to the second SMF, SMF-2 directly. In another example, redirection of the session management request to the second SMF, SMF-2 can be performed by the first SMF, SMF-1 by forwarding the request for a creation of a context (e.g. a Nsmf_PDUSession_CreateSMContext request) directly to the selected second SMF, SMF-2. The second SMF, SMF-2 replies to the AMF. The AMF accepts that the second SMF, SMF-2 is handling the PDU Session although the second SMF, SMF-2, was not selected by the AMF and / or SCP (service communication proxy). In any of the above example, the AMF and / or SCP which selected the first SMF, SMF-1 accepts that the first SMF, SMF-1 has decided to redirect the request. An indication of the reasoning for redirecting may be provide to the AMF and / SCP. The reasoning for the redirecting, for example, may be that dual steer support is required.

[0227] A request to establish a PDU session, a PDU session establishment request, from either to the first UE, UE1 where the dual steer device has two UEs or the part (communication capabilities) of the UE handling the first subscriber identifier where the dual steer device has one UE.

[0228] The PDU session establishment request may be a NAS SM message PDU session establishment request In some example embodiments, the SMF may receive the indication whether dual steer is required directly from AMF (e.g. outside the PDU session establishment request message). In this alternative, the indication whether dual steer is required may be included by the UE or relevant part (communication capabilities) of the UE in the NAS MM message UL NAS transport that carries the NAS SM message PDU session establishment request.

[0229] The second SMF, SMF 2, has the linked subscriber identifier SUPI and the linked (or dual steer) DNN / S-NSSAI information from the UDM. This linked subscriber identifier- SUPI and the linked (or dual steer) DNN / S-NSSAI information may be from SM subscription data in the UDM. Based on this information, the second SMF, SMF 2 is able to link the two PDU sessions associated with the second subscriber identifiers SUPIs of the dual steer device and select the same UPF for both of the PDU sessions.

[0230] The second SMF, SMF 2 may also select the same PCF. The second SMF, SMF 2 may provide the received dual steer information to the PCF. The received dual steer information may be provided to the PCF in SM policy association establishment. This allows the PCF to generate dual steer rules / policies and provide them to the second SMF, SMF 2. The second SMF, SMF 2 then further sends the rules / policies to the UPF and to the UE or relevant part (communication capabilities) of the UE.

[0231] If there is no indication that dual steer is required and / or the SMF does not support dual steering and / or the subscription (for example from the UDM) or relevant part (communication capabilities) of the UE does not allow dual steering for the subscriber identifier and DNN / S- NSSAI, the SMF establishes the PDU session as a regular PDU session.

[0232] Reference is now made to Fig. 6 which shows another example procedure in which a common SMF is used for a PDU session for the first subscriber identifier ,SUPI-1 of the dual steer device and for a PDU session for the second subscriber identifier, SUPI-2 of the dual steer.

[0233] The registration part of the procedure will now be described.

[0234] As referenced at 1, a registration procedure associated with the first subscriber identifier, SUPI-1 is triggered and a request for registration is sent to a first AMF, AMF1.

[0235] As referenced at 2, the first AMF, AMF1, provides request for registration to the UDM.

[0236] As referenced at 3, the UDM provides a response to the first AMF.

[0237] As referenced at 4, the first AMF, AMF1, sends a registration accept message to the dual steer device either to the first UE, UE1, where the dual steer device has two UEs or to the part (communication capabilities) of the UE handling the first subscriber identifier where the dual steer device has one UE.

[0238] As referenced at 5, a registration procedure associated with the second subscriber identifier, SUPI-2, is triggered and a request for registration is sent to a second AMF, AMF2.

[0239] As referenced at 6, the second AMF, AMF2, provides request for registration to the UDM.

[0240] As referenced at 7, the UDM provides a response to the second AMF.

[0241] As referenced at 8, the second AMF, AMF2, sends a registration accept message to the dual steer device either to the second UE, UE2, where the dual steer device has two UEs or to the part (communication capabilities) of the UE handling the second subscriber identifier where the dual steer device has one UE.

[0242] The PDU session establishment associated with the second subscriber identifier, SUPI- 2 will now be described.

[0243] As referenced at 9, when the second UE, UE2, or the part (communication capabilities) of the UE associated with the second subscriber identifier initiates a request for PDU Session establishment, an indication is provided as to whether dual steer is required for the requested PDU session.

[0244] The NAS SM message PDU Session establishment request may comprise dual steer related information, for example an indication as to whether dual steer is required.

[0245] Alternatively, the indication that dual steer is required is in the NAS MM message UL NAS transport that carries the NAS SM message PDU session establishment request.

[0246] As referenced at 10, the second SMF, SMF-2, receives a request for the creation of the context for the PDU session from the second AMF, AMF 2. The request may be a Nsmf PDUSession CreateSMContext Request . The request comprises the indication that dual steer is required.

[0247] As referenced at 11, the second SMF, SMF-2, may retrieve session management subscription data from the UDM. The second SMF, SMF-2, may perform a Nudm SDM Get operation to retrieve the session management subscription data from the UDM. The SMF may also provide to the UDM the indication that dual steer is required.

[0248] As referenced at 12, the UDM provides session management (SM) subscription data.

[0249] The session management (SM) subscription data in the UDM contains a linkage to the first subscriber identifier, SUPI-1 together with the DNN / S-NSSAI of that subscriber identity, SUPI-1 for which dual steer of traffic associated with the two subscriber identifiers SUPIs is applicable. If a SMF, for example SMF-1, is registered for the linked first subscriber identifier SUPI-1, a reference to that SMF, SMF-1 is provided in response to the second SMF, SMF-2. A reference to that SMF, may comprise one or more of a SMF set, a SMF instance, and / or a URJ for Nl l / N16 services.

[0250] The second SMF, SMF-2, redirects the session management request to the first SMF, SMF-1 using one of the alternatives below.

[0251] In a first alternative, As referenced at 13a, the second SMF, SMF-2 may send a redirection request to the second AMF, AMF2. The redirection request may comprise a reference to the first SMF, SMF-1 and / or reasoning for the redirection. The redirection request may request redirection to the identified SMF.

[0252] On example of a redirection request is an HTTPS REDIRECT .

[0253] Another example is an Nsmf PDUSession CreateSMContext Response.

[0254] As referenced at 13b, the second AMF, AMF2 then sends a request for the creation of the context for the PDU session to the first AMF, AMF-1. The request for the creation of the context for the PDU session may be a Nsmf PDUSession CreateSMContext request.

[0255] In a second alternative, as referenced at 13c, the second SMF, SMF-2 forwards the request for the creation of the context for the PDU session to the first SMF, SMF-1. The request for the creation of the context for the PDU session may be a Nsmf_PDUSession_CreateSMContext request,

[0256] Regardless of which of the first and second alternatives is used, As referenced at 14, the first SMF, SMF-1 handles the PDU session request. The first SMF, SMF-1 ensures that the same PCF and the same UPF that are handling the PDU session associated with the first subscriber identifier, SUPI-1 for the dual steer DNN / S-NSSAI which also selected for the session associated with the second subscriber identifier SUPI-2. The first SMF, SMF-la sends response for the creation of the context for the PDU session to the second AMF, AMF-1. The response for the creation of the context for the PDU session may be a Nsmf_PDUSession_CreateSMContext response.

[0257] In the case of the second alternative, the second AMF, AMF2 assumes that the request was forwarded to the first SMF, SMF-1 by the second SMF, SMF -2 for dual steer.

[0258] The NRF profile may be enhanced for NF registration and accordingly NF discovery for:

[0259] 1. a SMF to register with an indication of support for dual steering and other consumer NFs (e.g. AMF, SMF) to discover a SMF that supports dual steering.

[0260] 2. a PCF to register with indication of support for dual steering and other consumer NFs (e.g. SMF) to discover a PCF that supports dual steering.

[0261] 3. UPF to register with indication of support for dual steering and other consumer NFs (e.g. SMF) to discover a UPF that supports dual steering. A UE route selection policy (URSP) rule may contains a traffic descriptor (TD) that identifies the application and for each TD a one / more corresponding route selection descriptor (RSD) which provides the PDU session parameters e.g. PDU session type, DNN / S-NSSAI to be used, preferred access type etc. The URSP may include a dual steer indication in a RSD parameter. If a dual steer indication is present in the RSD parameter, this indicates to a UE or relevant part (communication capabilities) of the UE that for a PDU session to a DNN / S-NSSAI combination, the UE can request a dual steer PDU session. The UE route selection policy (URSP) may include a dual steer parameter “DualSteer Active = YES / NO” in a RSD, which indicates to the UE or relevant part (communication capabilities) of the UE whether this UE or the relevant part (communication capabilities) of the UE is the preferred active path or a standby path for the application identified by the TD.

[0262] If dual steer is required for a detected application matching a TD and the RSD in the URSP rule contains a dual steer indication for that application then the UE or the relevant part (communication capabilities) of the UE may include an indication that dual steering is required, for example “dual steer required=TRUE” . This indication that dual steering is required may be provided in a request for a PDU session establishment message. The request for a PDU session establishment message may be a NAS SM message PDU Session establishment request.

[0263] Alternatively, the indication that dual steering is required may be provided in a NAS MM message UL NAS Transport that carries the NAS SM message PDU Session establishment request.

[0264] Alternatively or additionally, the URSP can be enhanced to include dual steer access preference. The preference may indicate one or more preferred 3 GPP access RATs combinations, such as those previously discussed. The dual steer access preference may indicate, for a certain application, on which 3GPP RATs the dual steer PDUs are to be established.

[0265] Alternatively or additionally, the UE or relevant part (communication capabilities) of the UE may receive a validity criterion for RSDs that allows, enables or otherwise facilitates the use of some RSDs for a subscriber identifier, SUPI only if the UE or relevant part (communication capabilities) of the UE is capable of dual steering and dual steering has been requested.

[0266] Since the dual steering may be per service, the PCF may receive the subscriber identifier (for example SUPI-1) and associated subscriber identifier (for example SUPI-2) for a PDU session when the PDU session is associated with dual steering.

[0267] The PCF may indicate to the SMF the SDFs (service data flows) that use a PDU session associated with the first subscriber identifier, SUPI-and which have to use the other PDU session associated with the second subscriber identifier, SUPI-2.

[0268] The SMF may cause the same IP address to be assigned to the two PDU sessions and which of the two legs to use for DL traffic at UPF shall be based on policy received from the PCF.

[0269] The URSP rules may be configured so that the UL traffic uses one of the PDU sessions as a default (match all) and the other only for specific SDFs (service data flows).

[0270] In some example embodiments each subscriber identifier is provided with an indicator in the URSP rule, which indicates for a specific application traffic if the respective UE or part of the UE is dual steer active or in standby. This may be provided by a parameter in the RSD

[0271] The URSP may be for example: “Traffic Descriptor: Application descriptor=Appl; Route Selection Descriptor (RSD) will contain along with other parameter one dual steer parameter, for example dual steer active

[0272] = YES / NO”

[0273] For example:

[0274] The network sends a URSP or URSP rule to SUPI-1 with “Dual Steer Active = YES” for Appl

[0275] The network sends a URSP or URSP rulel to SUPI-2 with “Dual Steer Active = NO” for Appl

[0276] In some example embodiments, when RSD contains the parameter “Dual Steer Active = YES / NO”, (and / or any other suitable dual steer indication) the individual SUPIs sends this information to the dual steer layer.

[0277] The dual steer layer combines the rules and creates a dual steer rule, for example “Traffic Descriptor: Application descriptor=Appl; Dual Steer Active = SUPI-1 (or other internal identifier); Dual Steer Standby= SUPI-2 (or other internal identifier)

[0278] Reference is now made to Fig. 7 which shows a procedure in which UE route selection policy (URSP) provides support for dual steering.

[0279] As referenced at 1, the first subscriber identifier, SUPI-1 of the dual steer device is registered over a first network access, 3GPP 1.

[0280] As referenced at 2, the second subscriber identifier SUPI-2 of the dual steer device is registered over a second network access, 3 GPP 2

[0281] As referenced at 3 and 4, procedure is followed to deliver UE policy to the UE or relevant part (communication capabilities) of the UE that registered to the network.

[0282] In some example embodiments, this may the procedure "4.2.4.3 UE Configuration Update procedure for transparent UE Policy delivery" from 3 GPP standard TS 23.502

[0283] In some example embodiments, when subscriber identifier is being registered, the AMF performs UE policy association establishment with the PCF and then PCF delivers UE policies. URSP may be provided to the UE or relevant part (communication capabilities) of the UE. In some example embodiments, the URSP policy may include dual steer information such as discussed previously.

[0284] As referenced at 5, the dual steer device follows the URSP rules / policy to establish the two PDU sessions over different network accesses, for example two different 3GPP accesses. As referenced at 6, the dual steer device establishes a first PDU session via the first access network 3GPPls, 3 GPP 1. This is in respect of the first subscriber identifier, SUPI-1.

[0285] As referenced at 7, the dual steer device establishes a second PDU session via the second access network 3GPP2. This is in respect of the second subscriber identifier SUPI-2.

[0286] In the previous examples, reference has been made to the subscriber identifier being SUPIs. In some example embodiments, the subscriber identifier may be an GPSI (generic public subscription identifiers) or any other suitable identifiers.

[0287] FIG. 4 illustrates an example of an apparatus 201.

[0288] The apparatus 201 may comprise or implement one or more of the network functions shown in FIG. 1. The apparatus 201 may have at least one processor and at least one memory storing instructions of one or more the network functions shown in FIG. 1 that, when executed by at least one of the at least one processor cause operations or actions of the one or more network functions to be performed.

[0289] Alternatively, the apparatus 201 may comprise or implement at least a part of the dual steer device of Fig. 2 or of Fig. 3. The apparatus 201 may have at least one processor and at least one memory storing instructions that, when executed by at least one of the at least one processor cause operations or actions of at least a part of the dual steer device to be performed.

[0290] In some examples, the apparatus 201 may comprise at least one random access memory (RAM) 211a, and / or at least one read only memory (ROM) 211b. The apparatus 201 may comprise at least one processor 212, 213 and / or a network interface 214. The at least one processor 212, 213 may be coupled to the at least one memory which in some examples is the RAM 211a and the ROM 211b. The at least one processor 212, 213 may be configured to execute an appropriate software code 215.

[0291] The software code 215 may, for example, include software code of one or more of the network functions or at least a part of the dual steer device. The software code may include software code which allows the apparatus to perform one or more operations of one or more of the present aspects.

[0292] Reference is made to Fig. 8 which shows a method of some example embodiments.

[0293] This method may be performed by an apparatus.

[0294] The apparatus may comprise or implement an access and mobility function.

[0295] The apparatus may comprise suitable means, such as circuitry for providing the method.

[0296] Alternatively or additionally, the apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor cause the apparatus at least to provide the method below.

[0297] Alternatively or additionally, the apparatus may be such as discussed in relation to Fig. 4.

[0298] The method may be provided by computer program code or computer executable instructions.

[0299] The method may comprise as referenced Al, receiving a request for a first data session with an indication that dual steering is required in which the first data session is associated with a first subscription and uses a first network access to access a network data session.

[0300] The method may comprise as referenced A2, sending, to a session management function, a message comprising one or more of: an indication that dual steering is required; a subscriber identity associated with the first subscription; a subscriber identity associated with a second subscription associated with the dual steering; and / or information identifying a second data session associated with the dual steering.

[0301] It should be appreciated that the method outlined in Fig. 8 may be modified to include any of the previously described features.

[0302] Reference is made to Fig. 9 which shows a method of some example embodiments.

[0303] This method may be performed by an apparatus.

[0304] The apparatus may comprise or implement a session management function.

[0305] The apparatus may comprise suitable means, such as circuitry for providing the method. Alternatively or additionally, the apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor cause the apparatus at least to provide the method below.

[0306] Alternatively or additionally, the apparatus may be such as discussed in relation to Fig. 4.

[0307] The method may be provided by computer program code or computer executable instructions.

[0308] The method may comprise as referenced Bl, receiving from an access and mobility function, a session management message associated with a first data session, said first data session and a second data session together to provide dual steering, said first data session being associated with a first subscription and using a first network access to access a network and the second data session is associated with a second subscription and uses a second network access to access the network, said session management message comprising one or more of: an indication that dual steering is required; a subscriber identity associated with the first subscription; a subscriber identity associated with the second subscription; and / or information identifying the second data session.

[0309] It should be appreciated that the method outlined in Fig. 9 may be modified to include any of the previously described features.

[0310] Reference is made to Fig. 10 which shows a method of some example embodiments.

[0311] This method may be performed by an apparatus.

[0312] The apparatus may be a dual steer device.

[0313] The dual steer device may comprise a first user equipment, the first user equipment being associated with a first subscription.

[0314] The dual steer device may comprise a second user equipment, the second user equipment being associated with a second subscription.

[0315] The dual steer device may comprise a user equipment, a first subscription and a second subscription being associated with the user equipment.

[0316] The apparatus may comprise suitable means, such as circuitry for providing the method.

[0317] Alternatively or additionally, the apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor cause the apparatus at least to provide the method below.

[0318] Alternatively or additionally, the apparatus may be such as discussed in relation to Fig. 2, 3 or 4.

[0319] The method may be provided by computer program code or computer executable instructions.

[0320] The method may comprise as referenced Cl, receiving a user equipment routing policy comprising dual steering information.

[0321] The method may comprise as referenced C2, ensuring, based on the dual steering information of said user equipment routing policy, that a first data session with a network via a first access network and a second data session with the network via a second access network to provide dual steering are established, the first data session being associated with a first subscription and the second data session being associated with a second subscription.

[0322] It should be appreciated that the method outlined in Fig. 10 may be modified to include any of the previously described features. Reference is made to Fig. 11 which shows a method of some example embodiments.

[0323] This method may be performed by an apparatus.

[0324] The apparatus may comprise or implement an access and mobility function.

[0325] The apparatus may comprise suitable means, such as circuitry for providing the method.

[0326] Alternatively or additionally, the apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor cause the apparatus at least to provide the method below.

[0327] Alternatively or additionally, the apparatus may be such as discussed in relation to Fig. 4.

[0328] The method may be provided by computer program code or computer executable instructions.

[0329] The method may comprise as referenced DI, receiving a request for a first data session with an indication that dual steering is required, dual steering being provided by first data session which is associated with a first subscription and uses a first network access to access a network and by a second data session which is associated with a second subscription and uses a second network access to access the network, the request being associated with the first subscription.

[0330] The method may comprise as referenced D2, sending, to a first session management function, a session management message for the first session.

[0331] The method may comprise as referenced D3, receiving a response from a second session management function for the first data session, said second session management function handling the first and the second data sessions.

[0332] It should be appreciated that the method outlined in Fig. 11 may be modified to include any of the previously described features.

[0333] Reference is made to Fig. 12 which shows a method of some example embodiments.

[0334] This method may be performed by an apparatus.

[0335] The apparatus may comprise or implement a session management function.

[0336] The apparatus may comprise suitable means, such as circuitry for providing the method.

[0337] Alternatively or additionally, the apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor cause the apparatus at least to provide the method below.

[0338] Alternatively or additionally, the apparatus may be such as discussed in relation to Fig. 4.

[0339] The method may be provided by computer program code or computer executable instructions.

[0340] The method may comprise as referenced El, receiving at a first session management function, a session management message, from an access and mobility function, for a first data session with an indication that dual steering is required, dual steering being provided by first data session which is associated with a first subscription and uses a first network access to access a network and by a second data session which is associated with a second subscription and uses a second network access to access the network, the session management message being associated with the first subscription..

[0341] The method may comprise as referenced E2, retrieving subscription data associated with the first subscription, said subscription data comprising information indicating a second session management function associated with said second session.

[0342] The method may comprise as referenced E3, determining from said subscription data that the first data session is to be associated with the second management function.

[0343] It should be appreciated that the method outlined in Fig. 12 may be modified to include any of the previously described features.

[0344] Reference is made to Fig. 13 which shows a method of some example embodiments.

[0345] This method may be performed by an apparatus.

[0346] The apparatus may be a dual steer device.

[0347] The dual steer device may comprise a first user equipment, the first user equipment being associated with a first subscription.

[0348] The dual steer device may comprise a second user equipment, the second user equipment being associated with a second subscription.

[0349] The dual steer device may comprise a user equipment, a first subscription and a second subscription being associated with the user equipment.

[0350] The apparatus may comprise suitable means, such as circuitry for providing the method.

[0351] Alternatively or additionally, the apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor cause the apparatus at least to provide the method below.

[0352] Alternatively or additionally, the apparatus may be such as discussed in relation to Fig. 2, 3 or 4. The method may be provided by computer program code or computer executable instructions.

[0353] The method may comprise as referenced Fl, sending to the network a request to establish a first data session with an indication that dual steering is required for the first data session, dual steering being provided by the first data session which is associated with a first subscription and by a second data session which is associated with a second subscription, the request being associated with the first subscription.

[0354] The method may comprise as referenced F2, sending to the network user data associated with dual steering via the first data session.

[0355] It should be appreciated that the method outlined in Fig. 13 may be modified to include any of the previously described features.

[0356] Computer program code may be downloaded and stored in one or more memories of the apparatus described herein.

[0357] Therefore, although certain example embodiments were described above, by way of non-limiting and illustrative example, and with reference to certain example architectures for communication systems operated by mobile network operators, technologies and standards, further example embodiments may be applied to any other suitable forms of communication systems than those illustrated and described herein. For example, some example embodiments have been described in relation to a 5G communication system (5GS). It should be appreciated that other example embodiments may be provided in any other suitable communication system(s) or in any suitable combination with a 5GS.

[0358] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0359] As used herein, the expression “and / or” includes any and all combinations of the listed terms, including at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0360] As used herein, the term “or” refers to a non-exclusive “or” unless otherwise indicated (e.g., use of “or else” or “or in the alternative”).

[0361] As used herein, unless stated explicitly, performing a respective feature, step, or functionality “in response to A” does not indicate that the respective feature, step, or functionality is performed immediately after “A” occurs as one or more intervening features, steps, or functionalities may be included performed (at least in part) between an occurrence of the respective feature, step, or function and “A”. Analogously, performing a respective feature, step, or functionality “based on A” does not indicate that the respective feature, step, or functionality is performed solely based on “A” as the respective feature, step, or functionality may be further based on one or more other features, steps, or functionalities in addition to “A”.

[0362] In general, the various example embodiments of this disclosure may be implemented in hardware or special purpose circuitry, software, logic or any combination thereof. Some aspects of this disclosure may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the disclosure is not limited thereto. While various aspects of this disclosure may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting and illustrative examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0363] As used herein, the term “circuitry” may refer to one or more or all of the following:

[0364] (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and

[0365] (b) combinations of hardware circuits and software, such as (as applicable):

[0366] (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and

[0367] (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

[0368] (c) hardware circuit(s) and or processor(s), such as a microprocessor s) or a portion of a microprocessor s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.”

[0369] This definition of circuitry applies to all uses of this term herein , including in any claims. As a further example, as used here, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, an integrated circuit such as a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, and / or other computing or network device.

[0370] The various example embodiments of this disclosure may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and / or macros, may be stored in any apparatus-readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computerexecutable components which, when the program is run, are configured to carry out the various example embodiments of this disclosure. The one or more computer-executable components may be include software code or any portion(s ) thereof.

[0371] Further in this regard it should be noted that any blocks of the logic flow as in the Figs, may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on physical media such as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media (for example DVD and the data variants thereof, CD). The physical media is a non-transitory media.

[0372] The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0373] The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), FPGA, gate level circuits and processors based on multi core processor architecture, as non-limiting and illustrative examples.

[0374] The various example embodiments of the disclosure may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0375] The foregoing description has provided, by way of non-limiting and illustrative examples, a full and informative description of the various example embodiments of this disclosure. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the drawings and the claims. Indeed, there are further example embodiments comprising a combination of one or more example embodiments with any of the other example embodiments described herein. The scope of protection sought for some of the various example embodiments of this disclosure is set out by the claims. The various example embodiments in addition to its respective aspects and features thereof described herein that do not fall under the scope of the claims (if any) are to be interpreted as examples useful for understanding the various example embodiments of this disclosure. It should be noted that different claims with differing claim scope may be pursued in related applications, such as divisional or continuation applications.

Claims

CLAIMS1. A method comprising: receiving a request for a first data session with an indication that dual steering is required, dual steering being provided by first data session which is associated with a first subscription and uses a first network access to access a network and by a second data session which is associated with a second subscription and uses a second network access to access the network, the request being associated with the first subscription; sending, to a first session management function, a session management message for the first session; and receiving a response from a second session management function for the first data session, said second session management function handling the first and the second data sessions.

2. The method as claimed in claim 1, comprising, prior to receiving the response from the second session management function, receiving from the first session management function information indicating that a session management message for the first data session is to be sent to the second session management function.

3. The method as claimed in claim 2 wherein the information received from the first session management function indicates dual steering as a cause for sending of the session management message to the second session management function.

4. The method as claimed in claim 2 or 3, comprising prior to receiving the response from the second session management function, sending a session management message associated with the first data session to the second session management function for the first data session.

5. The method as claimed in any preceding claim, wherein the request for the first data session comprises an indication that dual steering is required.

6. The method as claim 1, comprising prior to receiving the response from the second session management function, receiving a session establishment request message from thesecond session management function, when the first session establishment request has been forwarded from the first session management function,7. A method comprising: receiving at a first session management function, a session management message, from an access and mobility function, for a first data session with an indication that dual steering is required, dual steering being provided by first data session which is associated with a first subscription and uses a first network access to access a network and by a second data session which is associated with a second subscription and uses a second network access to access the network, the session management message being associated with the first subscription; retrieving subscription data associated with the first subscription, said subscription data comprising information indicating a second session management function associated with said second season; and determining from said subscription data that the first data session is to be associated with the second management function.

8. The method as claimed in claim 7, comprising sending a response to the access and mobility function, indicating that the first data session is to be managed by the second session management function.

9. The method as claimed in claim 8, wherein the response comprises a request to redirect to the second session management function.

10. An apparatus comprising: means for sending to the network a request to establish a first data session with an indication that dual steering is required for the first data session, dual steering being provided by the first data session which is associated with a first subscription and by a second data session which is associated with a second subscription, the request being associated with the first subscription; and means for sending to the network user data associated with dual steering via the first data session.

11. The apparatus as claimed in claim 10, comprising means for sending a request to register to the network, the request to register associated with the first subscription, said request to register comprising an indication that dual steering is supported.

12. The apparatus as claimed in claim 10 or 11, wherein the apparatus comprises a first user equipment of a dual steer device, the first user equipment being associated with the first subscription.

13. The apparatus as claimed in claim 9, wherein the apparatus is the dual steer device and further comprises a second user equipment, the second user equipment being associated with the second subscription.

14. The apparatus as claimed in claims 10 or 11 wherein the apparatus comprises a user equipment of a dual steer device, the first subscription and the second subscription being associated with the user equipment.

15. The apparatus as claimed in claim 13 or 14, comprising means for sending a request to the network to establish the second data session, said request comprising an indication that dual steering is required for the second data session.

16. A method comprising: sending to the network a request to establish a first data session with an indication that dual steering is required for the first data session, dual steering being provided by the first data session which is associated with a first subscription and by a second data session which is associated with a second subscription, the request being associated with the first subscription; and sending to the network user data associated with dual steering via the first data session.

17. An apparatus comprising: means for receiving a request for a first data session with an indication that dual steering is required, dual steering being provided by first data session which is associated with a first subscription and uses a first network access to access a network and by a second data sessionwhich is associated with a second subscription and uses a second network access to access the network, the request being associated with the first subscription; means for sending, to a first session management function, a session management message for the first session; and means for receiving a response from a second session management function for the first data session, said second session management function handling the first and the second data sessions.

18. An apparatus comprising: means for receiving, at a first session management function, a session management message, from an access and mobility function, for a first data session with an indication that dual steering is required, dual steering being provided by first data session which is associated with a first subscription and uses a first network access to access a network and by a second data session which is associated with a second subscription and uses a second network access to access the network, the session management message being associated with the first subscription; means for retrieving subscription data associated with the first subscription, said subscription data comprising information indicating a second session management function associated with said second season; and means for determining from said subscription data that the first data session is to be associated with the second management function.

19. A computer program comprising computer executable code which when run cause the method of any of claims 1 to 9, and 16 to be performed.

Images