Apparatus, methods, and computer programs

Abstract

A method comprising: sending, to a user plane function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising second dual steer information, said dual steer information comprising dual steer information providing a link to a first packet forwarding control protocol session for a first packet data unit session, the second packet forwarding control protocol session being for a second packet data unit session, said first and second packet data unit sessions supporting dual steering; and receiving, from the user plane function, the same address for the second packet data unit session as for the first packet data unit session, in response to the request to establish or modify the second packet forwarding control protocol session.

Description

[0001] APPARATUS, METHODS, AND COMPUTER PROGRAMS

[0002] Technical Field

[0003] This disclosure relates to methods, an apparatus and computer programs, and in particular - but not exclusively - to methods, apparatus and computer programs 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 a first aspect, there is provided a method comprising: sending, to a user plane function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising second dual steer information, said dual steer information comprising dual steer information providing a link to a first packet forwarding control protocol session for a first packet data unit session, the second packet forwarding control protocol session being for a second packet data unit session, said first and second packet data unit sessions supporting dual steering; and receiving, from the user plane function, the same address for the second packet data unit session as for the first packet data unit session, in response to the request to establish or modify the second packet forwarding control protocol session.

[0010] The method may comprise, prior to the sending the request to establish or modify the second packet forwarding control protocol session: sending, to the user plane function, a request to establish or modify the first packet forwarding control protocol session, said request to establish or modify the first packet forwarding control protocol session comprising first dual steer information; and receiving, from the user plane function, the address for the first packet data unit session, in response to the request to establish or modify the first packet forwarding control protocol session.

[0011] The method may comprise: sending to a policy control function, a request for a session management policy association for the first packet data unit session, said request for session management policy association for the first packet data unit session comprising dual steer related information; and receiving from the policy control function, policy information.

[0012] The dual steer related information provided in the request for session management policy association for the first packet data unit session may comprise at least one of: an indicator that the session management policy association is for a dual steer packet data unit session; an identifier of a dual steer bundle of associated packet data unit sessions supporting dual steering; a dual steer identifier for the first session management policy association session; a common dual steer identity for the first session management policy association session and for a second session management policy association associated with the second packet data unit session; or a linked dual steer identity of the second session management policy association session; or a session management policy association session identifier of the first session management policy association session.

[0013] The method may comprise: sending to a policy control function, a request for a session management policy association for the second packet data unit session, said request for session management policy association for the first packet data unit session comprising the dual steer related information; and receiving from the policy control function, policy information.

[0014] The request for a session management policy association for the packet data unit session may corresponds to one of a request to establish, a request to modify the session management policy association or to notify events on the session management policy association.

[0015] The dual steer related information provided in the request for session management policy association for the second packet data unit session may comprise at least one of: an indicator that the session management policy association is for a dual steer packet data unit session; an identifier of a dual steer bundle of associated packet data unit sessions supporting dual steering; a dual steer identifier for the second session management policy association session; a common dual steer identity for the first session management policy association session and for the second session management policy association; a linked dual steer identity of the first session management policy association session; or a session management policy association session identifier of the second session management policy association session.

[0016] The policy may comprise at least one of: one or more rules applicable to the first and the second packet data unit sessions; one or more rules applicable to the first packet data unit session; or one or more rules applicable to the second packet data unit session.

[0017] The method may comprise providing the user plane function with one or more packet processing rules, wherein the packet processing rules comprise at least one of: one or more rules applicable to the first and the second packet forwarding control protocol sessions; one or more rules applicable to the first packet forwarding control protocol session; or one or more rules applicable to the second packet forwarding control protocol session.

[0018] The method may be performed by an apparatus.

[0019] The apparatus may comprise means for implementing the method.

[0020] 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 first aspect.

[0021] The apparatus may implement a session management function.

[0022] According to a second aspect, there is provided a method comprising: receiving, from a session management function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising second dual steer information, said dual steer information comprising dual steer information providing a link to a first packet forwarding control protocol session for a first packet data unit session, the second packet forwarding control protocol session being for a second packet data unit session, said first and second packet data unit sessions being associated packet data unit sessions supporting dual steering; storing an association between the first and second packet forwarding control protocol sessions; and sending, to the session management function, the same address for the second packet data unit session as for the first packet data unit session, in response to the request. The method may comprise, prior to receiving the request to establish or modify the second packet forwarding control protocol session: receiving, from the same or a different session management function, a request to establish or modify the first packet forwarding control protocol session, said request to establish or modify the first packet forwarding control protocol session comprising first dual steer information; and sending, to the said same or different session management function, the address for the first packet data unit session, in response to the request to establish or modify the first packet forwarding control protocol session.

[0023] The method may be performed by an apparatus.

[0024] The apparatus may comprise means for implementing the method.

[0025] 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.

[0026] The apparatus may implement a user plane function.

[0027] One or more of the following features may be used in conjunction with the first and / or second aspects.

[0028] The first dual steer information may comprise at least one of: an indication that the first packet forwarding control protocol session is a packet forwarding control protocol session for a dual steer packet data unit session; an identifier of a dual steer bundle of associated packet data unit sessions supporting dual steering; a dual steer identifier for the first packet forwarding control protocol session; a common dual steer identity for the first and second packet forwarding control protocol sessions; a linked dual steer identity of the second packet forwarding control protocol session; or a packet forwarding control protocol identifier of the first packet forwarding control protocol session.

[0029] The second dual steer information may comprise at least one of: an indication that the second packet forwarding control protocol session is a packet forwarding control protocol session for a dual steer packet data unit session; an identifier of a dual steer bundle of associated packet data unit sessions supporting dual steering; a dual steer identifier of the second packet forwarding control protocol session; the common dual steer identity for the first and second packet forwarding control protocol sessions; a linked dual steer identity of the first packet forwarding control protocol session; or a packet forwarding control protocol identifier of the second packet forwarding control protocol session. A respective dual steer identifier for a respective session may be based on a respective subscriber identifier of a dual steer device and an identifier associated with the respective packet data unit session.

[0030] A respective linked dual steer identifier may be based on a respective subscriber identifier of a dual steer device and an identifier associated with the respective other packet data unit session.

[0031] The request to establish or modify the second packet forwarding control protocol session may comprise the address requested to be used by the user plane function for the second packet data unit session.

[0032] According to a third aspect, there is provided a method comprising: sending, to a user plane function, a request to establish or modify a first packet forwarding control protocol session, said request to establish or modify the first packet forwarding control protocol session comprising an address to be used for the first packet data unit session, the first packet forwarding control protocol session being associated with a first packet data unit session; receiving, from the user plane function, a response to the request; sending, to the user plane function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising the address to be used for the second packet data unit session, the same address being used for the second packet data unit session as for the first packet data unit session, said first and second packet data unit sessions being associated packet data unit sessions supporting dual steering; and receiving, from the user plane function, a response to the request accepting that the same address is being used for the second packet data unit session.

[0033] The method may comprise providing the user plane function with one or more packet processing rules, wherein the packet processing rules comprise at least one of one or more rules applicable to the first and the second packet forwarding control protocol sessions; one or more rules applicable to the first packet forwarding control protocol session; or one or more rules applicable to the second packet forwarding control protocol session.

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

[0035] The apparatus may comprise means for implementing the method.

[0036] 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 third aspect. The apparatus may implement a session management function.

[0037] According to a fourth aspect, there is provided a method comprising: receiving, from a session management function, a request to establish or modify a first packet forwarding control protocol session, said request to establish or modify the first packet forwarding control protocol session comprising an address to be used for the first packet data unit session, the first packet forwarding control protocol session being associated with a first packet data unit session; sending, to the session management function, a response to the request; receiving, from the same or a different session management function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising the address to be used for the second packet data unit session, the same address being used for the second packet data unit session as for the first packet data unit session, said first and second packet data unit sessions being associated packet data unit sessions supporting dual steering; and sending, to said same or different session management function, a response to the request accepting that the same address is being used for the second packet data unit session.

[0038] The method may be performed by an apparatus.

[0039] The apparatus may comprise means for implementing the method.

[0040] 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.

[0041] The apparatus may implement a user plane function.

[0042] One or more of the following features may be used in conjunction with the third and / or fourth aspects.

[0043] The request to establish or modify the second packet forwarding control protocol session may comprise an indication that the second packet forwarding control protocol session is for a dual steer packet data unit session.

[0044] The address may comprise an IP address, an internet protocol IP address prefix or a media access control MAC address.

[0045] The address may comprise an address associated with dual steer device supporting dual steering.

[0046] The method may comprise providing the user plane function with one or more packet processing rules, wherein the packet processing rules comprise at least one of: one or more rules applicable to the first and the second packet forwarding control protocol sessions; one or more rules applicable to the first packet forwarding control protocol session; or one or more rules applicable to the second packet forwarding control protocol session.

[0047] According to a fifth aspect, there is provided a method comprising: receiving a packet associated with a first packet forwarding control protocol session; determining which of packet detection rules associated with the first packet forwarding control protocol session and a second packet forwarding control protocol session, wherein the first and second packet forwarding control protocol sessions are for associated packet data unit sessions supporting dual steering, has a highest precedence; and applying one or more instructions of the packet detection rule with the highest precedence to the packet.

[0048] The packet may be a downlink packet.

[0049] The method may comprise determining the packet matches the first packet forwarding control protocol session and looking up the second packet forwarding control protocol session supporting dual steering with the first packet forwarding control protocol session.

[0050] The instructions associated with the packet detection rule may define the steering, splitting and / or switching of the packets between the first and second sessions. The DL packet data record ma comprise the dual steer rule identity.

[0051] The instructions associated with the packet detection rule may define a steering functionality to be used.

[0052] The steering functionality may comprise at least one of access traffic steering, switching, splitting low layer, multi path transmission control protocol, or multipath QUIC.

[0053] The instructions associated of the packet detection rule may define a steering mode.

[0054] The steering mode may comprise at least one of active / standby; smallest delay; load balancing; priority based; or redundant.

[0055] According to a sixth aspect, there is provided a method comprising: determining that a first session management function, serving a first packet data unit session and a second packet data unit session, is no longer able to support the first packet data unit session and the second packet data unit session, the first and second packet data unit sessions being associated packet data unit sessions supporting dual steering; and moving the first and second packet data unit sessions to a second session management function, said second session management function belonging to a same session management function set as the first session management function. According to a seventh aspect, there is provided a method comprising: determining that a first session management function, serving a first packet data unit session supporting dual steer, is no longer able to support the first packet data unit session; and moving the first packet data unit session to a second session management function, said second session management function supporting a second packet data unit session, the first and second packet data unit sessions supporting dual steering.

[0056] According to an eighth aspect, there is provided a method comprising: determining that a first session management function, serving a first packet data unit session and a second packet data unit session, is no longer able to support the first packet data unit session and the second packet data unit session, the first and second packet data unit sessions supporting dual steering; and moving session management policy association for the first and second packet data unit sessions to a second session management function, said second session management function belonging to a same session management function set as the first session management function.

[0057] According to a ninth aspect, there is provided a method comprising: determining that a first session management function, serving a first packet data unit session supporting dual steer, is no longer able to support the first packet data unit session; and moving session management policy association for the first packet data unit session to a second session management function, said second session management function supporting a second packet data unit session, the first and second packet data unit sessions supporting dual steering.

[0058] According to a tenth aspect, there is provided a method comprising: providing a first dual steer packet forwarding control protocol session for a first packet data unit session, the first dual steer packet forwarding control protocol session being associated with a first subscriber identifier associated with a dual steer device; providing a second dual steer packet forwarding control protocol session for a second packet data unit session, the second dual steer packet forwarding control protocol session being associated with a second subscriber identifier associated with the dual steer device, said first and second packet data unit sessions supporting dual steering; and intercepting or tracing dual steer traffic using one of said first and second identifiers, to intercept or trace dual steer traffic of both of the first and second packet data unit sessions.

[0059] According to a eleventh aspect, there is provided a method comprising: providing a first session management policy association for a first packet data unit session, the first session management policy association associated with a first subscriber identifier associated with a dual steer device; providing a second session management policy association for a second packet data unit session, the second session management policy association being associated with a second subscriber identifier associated with the dual steer device, said first and second packet data unit sessions supporting dual steering; and intercepting or tracing dual steer traffic using one of said first and second identifiers, to intercept or trace dual steer traffic of both of the first and second packet data unit sessions.

[0060] According to a twelfth aspect, there is provided a method comprising: based on a common address or a common dual steer identifier, retrieving information about a first packet data unit session and a second packet data unit session, said first and second packet data unit sessions together supporting dual steering and binding the information about the first and second packet data unit sessions together to a dual steer bundle.

[0061] For one or more of the fifth, sixth, seventh and tenth aspects, the method may be performed by an apparatus.

[0062] 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 respective aspect.

[0063] The apparatus may comprise means for implementing the method.

[0064] The apparatus may implement a user plane function.

[0065] For one or more of the eighth, ninth, eleventh and twelfth aspects, the method may be performed by an apparatus.

[0066] 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 respective aspect.

[0067] The apparatus may comprise means for implementing the method.

[0068] The apparatus may implement a policy control function.

[0069] 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.

[0070] 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. 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.

[0071] 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.

[0072] Various other aspects are also described in the following detailed description and in the attached claims.

[0073] Brief Description of the Figures

[0074] 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:

[0075] Fig. 1 shows a schematic representation of a 5G system;

[0076] Fig. 2 shows schematically a first example of a dual steer device and a UPF of a 5GC;

[0077] Fig. 3 shows schematically a second example of a dual steer device and a UPF of a 5GC;

[0078] Fig. 4 shows a schematic representation of an apparatus;

[0079] Figs. 5a and b schematically shows a first procedure in which a same address is used for two PF CP sessions;

[0080] Fig. 6 schematically shows a downlink DL packet processing flow;

[0081] Fig. 7 shows a first method of some example embodiments;

[0082] Fig. 8 shows a second method of some example embodiments;

[0083] Fig. 9 shows a third method of some example embodiments;

[0084] Fig. 10 shows a fourth method of some example embodiments:

[0085] Fig. 11 shows a fifth method of some example embodiments;

[0086] Fig. 12 shows a sixth method of some example embodiments:

[0087] Fig. 13 shows a seventh method of some example embodiments;

[0088] Fig. 14 shows an eighth method of some example embodiments;

[0089] Fig. 15 shows a ninth method of some example embodiments:

[0090] Fig. 16 shows a tenth method of some example embodiments;

[0091] Fig. 17 shows an eleventh method of some example embodiments: and

[0092] Fig. 18 shows a twelfth method of some example embodiments. Detailed Description

[0093] In the following, the various example embodiments of this disclosure 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.

[0094] FIG. 1 shows a schematic representation of a communication network comprising a 5G system (5GS).

[0095] The communication may comprise a public land mobile network (PLMN). The PLMN may comprise a wireless access network comprising a plurality of access nodes (AN), 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 ANs. The dual steer devices 200 / 300 of some example embodiments are described in more detail later.

[0096] The access network may be a 3 GPP access network. For example, the access network may be a radio access networks (RAN) specified in 3GPP standardisation, such as 5G RAN. Other examples of access networks may be untrusted or wireline non 3 GPP access to a 3 GPP 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 non-terrestrial (radio access) network. In another example, the two (R)AN may be operated by different operators e.g. different PLMN(s). In this latter option, the RANs may be controlled by different AMF(s).

[0097] 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.

[0098] The 5GC shown in Fig. 1 comprise 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.

[0099] Some example embodiments relate to a so-called “dual steer device”. 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.

[0100] 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.

[0101] 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.

[0102] 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).

[0103] The first and second subscriber identities may be linked to a single subscription profile.

[0104] When a dual steer device provides dual steering, the dual steer device has a first data session with a network associated with the first subscriber identifier and via a first access network and a second data 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 data sessions. The traffic may be steered, switched and / or split between the first and second sessions.

[0105] The traffic may, for example, comprise data from an application of the dual steer device.

[0106] The first and second sessions may be packet data unit (PDU) sessions.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] The dual steer device may support, if required, simultaneous data transmission over both of the two access networks.

[0112] The traffic which is managed by the dual steer layer may comprise application traffic from an application 202 or any other suitable traffic.

[0113] In some example embodiments, the dual steer device may be provided, for example, within a single housing.

[0114] 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.

[0115] 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 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] In some example embodiments, the dual-steer device may support traffic steering, splitting, and / or switching of the user data across two access networks.

[0122] 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.

[0123] In some example embodiments, the dual-steer device may aim to minimize service interruption when switching the user data, between the two access networks.

[0124] 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).

[0125] 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 3GPP 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.

[0126] A dual steer PDU (packet data unit) session is a PDU session that is triggered by a dual steer device and is intended to be used for dual steering. Dual steering is steering, switching and / or splitting of traffic. The traffic may be of an application.

[0127] In the following examples, a dual steer device with two UEs each having its own subscriber identifier is used to illustrate some example embodiments. However, it should be appreciated that the example embodiments may also be used with a dual steer device having a UE with one part associated with one subscriber identifier and one part associated with the other subscriber identifier. In the following references to parts of the UE are to a dual steer device which has a UE with one part associated with the first subscriber identifier and one part associated with the second subscriber identifier.

[0128] For a dual steer device to achieve dual steering, the dual steer device registers with each of the two access networks (which may be the same or different). The two access networks may each be a 3 GPP network access.

[0129] Each registration is triggered by a different subscription, for example SUPI and / or IMSI (international mobile subscriber identity). After registration, the dual steer device establishes two dual steer PDU sessions, one for each different subscription.

[0130] A first dual steer PDU session, PDU session 1 that goes over the first access network, where the first dual steer PDU session, PDU session 1 corresponds to the first identity, SUPI- 1. The first identity, SUPI-1 corresponds to the first registration. The first dual steer PDU session, PDU session 1 has a leg (user-plane resources) on the first access network.

[0131] A second dual steer PDU session, PDU session 2 that goes over the second access network, where the second dual steer PDU session, PDU session 2 corresponds to the second identity, SUPI-2. The second identity, SUPI-2 corresponds to the second registration. The second dual steer PDU session, PDU session 2 has a leg (user-plane resources) on the second access network.

[0132] In some example embodiments, the dual steer device may have a common network access for both of the sessions associated with different subscriptions. The two UEs of the dual steer device or the two parts of the UE may be connected to the same cell. In other words, the two sessions may be via a common access network. The first and second access network in the above example may the same access network.

[0133] The first and second dual steer PDU sessions may serve certain application traffic.

[0134] In some example embodiments, the core network may be the same for both registrations. When the dual steer device needs to start working in a dual steer mode in order to serve an application that requires dual steering, the same address is allocated and used for the two dual steer PDU sessions.

[0135] Some example embodiments may ensure that same UE IP address is used for the two dual steer PDU sessions. This may be required in some example embodiments for handling certain application traffic.

[0136] The PDU sessions that need to be linked together due to dual steer may provide a dual steer bundle. In the example embodiments, two bundled PDU sessions may be provided for dual steering. However, it should be appreciated that in some example embodiments, there may be more than two bundled PDU sessions.

[0137] In some example embodiments, the two dual steer PDU sessions may be served by the same SMF.

[0138] In some example embodiments, the two dual steer PDU sessions may be served by different SMFs from a same SMF set.

[0139] In some example embodiments, the two dual steer PDU sessions may be served by the same UPF.

[0140] In some example embodiments, the two dual steer PDU sessions may be served by the same PCF.

[0141] In some example embodiments, two PFCP (protocol forwarding control protocol) sessions may be established for the two dual steer PDU sessions, one PFCP session per dual steer PDU session.

[0142] In some example embodiments, two PFCP sessions may be established in the UPF for the two dual steer PDU sessions, one PFCP session per dual steer PDU session.

[0143] The two dual steer PDU session and the two related PFCP sessions are assigned the same UE IP address.

[0144] The SMF may provide dual steer related information at PFCP session creation / modification. The dual steer related information may comprise correlation information enabling the UPF to correlate the two dual steer PFCP sessions. The term "dual steer PFCP session" refers to a PFCP session that is established for a dual steer PDU session.

[0145] The SMF may provide to the UPF information instructing the UPF to assign the same UE IP address to the two PFCP sessions.

[0146] In some example embodiments, the SMF may provide to the UPF, for each PFCP session one or more of: an indication that the PFCP session is a dual steer PFCP session; a dual steer ID (identifier); and / or a linked dual steer ID set to the dual steer ID of the other dual steer PFCP session.

[0147] In other example embodiments, the SMF may provide to the UPF, for each PFCP session one or more of: an indication that the PFCP session is a dual steer PFCP session; and / or a dual steer ID per PFCP session, with the same dual steer ID assigned to both dual steer PFCP sessions.

[0148] The two dual steer PDU sessions, and the two related PFCP sessions, are assigned the same UE IP address.

[0149] In some example embodiments, the dual steer ID may be set to, or be associated with, the SUPI and the PDU Session ID associated with the dual steer PFCP session. In other example embodiments, the dual steer ID may be set to an identifier chosen by the SMF or provided by the PCF.

[0150] In some example embodiments, the linked dual steer ID may be set to, or associated with, the SUPI and PDU session ID of the other dual steer PDU session, in order to uniquely identify a certain dual steer PDU session within a certain UE.

[0151] In some example embodiments, the dual steer ID and the linked dual steer ID may be defined in the DL PDRs (packet detection rules) or DL traffic endpoint comprising the UE IP address.

[0152] In some example embodiments, no linked dual steer ID is provided, only a dual steer ID and the same dual steer ID is provided for each dual steer PFCP session, thus enabling the UPF to correlate the two dual steer PFCP sessions using the same dual steer ID.

[0153] In some example embodiments, the UPF may assign the same UE IP address to both dual steer PFCP sessions. This may be based on the information received from the SMF, such as previously described. In other example embodiments, the SMF may provide the UPF with the UE IP address already assigned to the first dual steer PFCP session, when establishing the second dual steer PF CP session.

[0154] In other example embodiments, the SMF may provide the UPF with the UE IP address in 5GC deployments where the UE IP addresses are usually assigned by the UPF. For example, the UPF accepts being instructed to assign a specific UE IP address (which is provided by the SMF) to a dual steer PFCP session. The UPF will know that a PFCP session is a dual steer PFCP session based on one or more dual steer indicators. The one or more dual steer indicators may be as previously described.

[0155] In 5GC deployments, UE IP addresses may be assigned by UPF (e.g. for SMF set deployment) or by the SMFs. This may be based on the policies of the operator of the network.

[0156] In some example embodiments where the UPF assigns the UE IP address, if one of the two PFCP sessions has already been established, the UPF may assign the same UE IP address to the second PFCP session when the latter is established. If none of the two PFCP sessions has been established yet, the UPF assigns a new UE IP address to the PFCP session being established. In either case, the UPF indicates the UE IP address assigned to each PFCP session in its response to the SMF(s).

[0157] In some example embodiments where the SMF assigns the UE IP address, the SMF provides the UE IP address already assigned to the first dual steer PDU session when establishing the PFCP session of the second dual steer PDU session.

[0158] The indication that the PFCP session is a dual steer PFCP session may be use by the UPF, in deployments where the UE IP addresses are assigned by the SMF, to accept the SMF imposing the same UE IP address of the PFCP session.

[0159] The indication that the PFCP session is a dual steer PFCP session may be use by the UPF, in deployments where the UE IP addresses are assigned by the UPF, to allocate the same UE IP address for the 2 PFCP session.

[0160] In some example embodiments, the dual steer bundle ID and / or the dual steer ID values used on the UPF and on the PCF interface do not need to have the same values (for PCF interface and for UPF interface.

[0161] Reference is made to Fig. 5a and 5b, which show a procedure in which the UPF allocates the same UE IP address to the two PFCP sessions, of some example embodiments. Signalling between the UE(s) and the SMF transit via different access networks (for example, 3 GPP access 1 and 3 GPP access 2) and the AMF to reach the SMF, However, it should be noted that this is not shown in Fig. 5a and 5b.

[0162] In the example embodiments shown in Fig. 5a and Fig. 5b, 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 a first part of the UE and UE 2 should be considered as corresponding to a second part of the UE.

[0163] As referenced at 0, the first UE, UE-1, is registered over the first network access, 3GPP access 1, and establishes a first dual steer PDU session, PDU1, over the first network access, 3 GPP access 1.

[0164] As referenced at 1, the SMF establishes an SM (session management) policy association for the first PDU session, PDU1. The SMF may send to the PCF a SM policy association request comprising one or more of: the first subscriber identifier, SUPI 1; the UE IP address and / or prefix; the dual steer bundle ID; the dual steer session ID; and / or a dual steer SM policy association indication.

[0165] The establishing of the SM policy association may generally be as described in TS 23.502 clause 4.16.4 but modified to include the information discussed previously which is sent by the SMF to the PCF. The information may be sent in a message, such as an Npcf SMPolicyControl Create message. Alternatively or additionally, at least a part of the information may also be sent in an Npcf SMPolicyControl Update message.

[0166] The PCF responds to the request with the policy information. This may comprise policy information targeting the bundle which is indicated by a dedicated tag in the corresponding PCC rules or PDU session related policy information (for example the Session MBR information may apply for the bundle). This may include DL PDR(s) and their dual steer Rule.

[0167] The part of the procedure referenced at 2 may take place before or after the part of the procedure referenced at 3. This order may depend on local policies of the SMF. In general, an SM Policy control create is performed before the PFCP session (as for example shown in part 6 of the procedure).

[0168] As referenced at 2, the SMF establishes a PFCP session for the first PDU session, PDU1. As part of this, the SMF may send a dual steer PFCP session indication and / or a dual steer bundle ID and / or a dual steer session ID to the UPF. The SMF may send a request to allocate a UE IP address and / or IPv6 prefix to the UPF. This may be with the dual steer PFCP session indication and / or a dual steer bundle ID and / or a dual steer session ID.

[0169] The dual steer global bundle ID may be allocated by the SMF. The same value is used in the part of the procedure referenced at 6 for the second PFCP session.

[0170] The dual steer session ID may be allocated by the SMF to the PDU session. The same value is used in the part of the procedure referenced at 6 for the second PFCP session.

[0171] The UPF responds to the request from the SMF with the UE IP address and / or prefix that the UPF has allocated.

[0172] After PFCP session establishment, an SM policy control update procedure optionally may be performed (for example as shown in part 3 of the procedure).

[0173] As referenced at 3, the SMF updates an SM (session management) policy association update for the first PDU session, PDU1. The SMF may send, to the PCF, an SM policy association request comprising one or more of the first subscriber identifier, SUPI 1; the UE IP address and / or prefix; the dual steer bundle ID; the dual steer session ID; and a dual steer SM policy association indication.

[0174] The establishing or updating of the SM policy association may generally be as described in TS 23.502 clause 4.16.4 but modified to include the information discussed previously which is sent by the SMF to the PCF. The information may be sent in a message, such as an Npcf SMPolicyControl Create message. Alternatively or additionally, at least a part of the information may be sent in an Npcf SMPolicyControl Update message.

[0175] The PCF responds to the request from the SMF with policy information. This may include policy information targeting the bundle which is indicated by a dedicated tag in the corresponding PCC (policy and charging control) rules or PDU session related policy information (for example the Session MBR (maximum bit rate) information may apply for the bundle). This may include DL PDR(s) and their associated dual steer rule.

[0176] As referenced at 4, the PDU session establishment proceeds further and the SMF replies to the PDU session establishment request of the first UE, UE1. The establishment of the first PDU session, PDU1, has been completed. The SMF reply to the PDU session establishment request may include dual steer related rules sent to the UE and based on the policy information targeting the bundle received in step 3 As referenced at 5, the second UE, UE-2, is registered over the second network access, 3GPP access 2, and establishes a second dual steer PDU session, PDU2, over the second network access, 3 GPP access 2.

[0177] As referenced at 6, the SMF establishes an SM (session management) policy association for the second PDU session, PDU2. The SMF may send to the PCF a SM policy association request comprising one or more of: the second subscriber identifier, SUPI 2; the UE IP address and / or prefix; the dual steer bundle ID; the dual steer session ID; a linked dual steer session ID; and / or a dual steer SM policy association indication.

[0178] The dual steer bundle ID may be the same value as used in the part of the procedure referenced 3.

[0179] The dual steer session ID may be the value allocated by the SMF to the second PDU session, PDU 2, then the same value may be sent as linked Dual Steer ID on the first SM Policy association.

[0180] The linked dual steer session ID may be the same value as the dual steer session ID used in the part of the procedure referenced 3.

[0181] The establishing of the SM policy association may generally be as described in TS 23.502 clause 4.16.4 but modified to include the information discussed previously which is sent by the SMF to the PCF. The information may be sent in a message, such as an Npcf SMPolicyControl Create message. Alternatively or additionally, at least a part of the information may also be sent in an Npcf SMPolicyControl Update message.

[0182] The PCF responds to the request with the policy information. This may comprise policy information targeting the bundle which is indicated by a dedicated tag in the corresponding PCC rules or PDU session related policy information (for example the Session MBR information may apply for the bundle). This may include DL PDR(s) and their dual steer Rule.

[0183] As referenced at 7, the SMF establishes a PFCP session for the second PDU Session. As part of this procedure, the SMF may send to the UPF one or more of: the UE IP address and / or prefix; a dual steer PFCP session indication; a dual steer bundle ID; and / or a dual steer session ID.

[0184] The dual steer bundle ID may be the same value as used in the part of the procedure referenced 3. The same value is used for the first PFCP session. The dual steer session ID may be the value allocated by the SMF to the second PDU session, PDU 2, then the same value is sent as linked dual steer ID for the first PFCP session, in the part of the procedure referenced 8 and described below.

[0185] The linked dual steer session ID may be the same value as the dual steer session ID used in the part of the procedure referenced 3.

[0186] As referenced at 8, the SMF may update the first PCFP session for example to provide the linked dual steer ID. This may be the dual steer session ID allocated in the part of the procedure referenced step 7.

[0187] As referenced at 9, the PDU session establishment proceeds further and the SMF replies to the PDU session establishment request of the second UE, UE2. The establishment of the second PDU session, PDU2, has been completed. The SMF reply to the PDU session establishment request may include dual steer related rules sent to the UE and based on the policy information targeting the bundle received in in the part of the procedure referenced at 6.

[0188] As an alternative to the example embodiments described in relation to Fig. 5a and Fig. 5b, the dual steer session ID may be allocated by the SMF or by the PCF

[0189] The UPF is configured to process the DL packets where the two dual steer PFCP sessions share the same UE IP address.

[0190] The PFCP model currently does not allow PFCP sessions for regular PDU sessions to have overlapping DL PDRs and therefore to have DL PDRs with the same UE IP address. Accordingly, some example embodiments extend the PFCP model to allow two dual steer PFCP sessions to be provisioned with overlapping PDRs, i.e. with the same UE IP address. As an example of such embodiments, the PDI (packet detection information) may include a dual steer information. The dual steer information may comprise one or more of: the dual steer ID; the linked dual steer ID; and / or the dual steer bundle ID. The dual steer information is considered by the UPF and allows overlapping PDRs, i.e. with the same UE IP address.

[0191] Where the UPF has knowledge that the two PFCP sessions are part of a bundle, the PDR / PDI may be not provide the bundling information.

[0192] In some example embodiments, session binding is the association of the session information to one PDU session or to a dual steer bundle. The PCF may perform the session binding, which may take the following PDU Session parameters into account: a) For an IP type PDU Session, the UE IPv4 address and / or IPv6 prefix. In some example embodiments, for an Ethernet type PDU Session, the UE MAC address(es). In other example embodiments, any other suitable UE address may be taken into account; b) The UE identity (e.g. SUPI), if present; c) The information about the data network (DN) the user is accessing, e.g. DNN (data network name) and slice information (S-NSSAI), if present.

[0193] Once the PCF has determined the impacted PDU Session(s), and here instead of determining one PDU Session, the PCF in case of bundled PDU Sessions may determine more than one PDU Session, the PCF may identify the PCC rules affected by the AF session information, including new PCC rules to be installed and existing PCC rules to be modified or removed.

[0194] For each PDU session, the SMF establishes a PF CP session in the UPF using the PF CP protocol providing a set of rules to the UPF. The rules may comprise one or more of packet detection rules (PDRs), QoS enforcement rules (QERs), usage reporting rules (URRs), FARs (forwarding action rules) and MARs (multi-access rules).

[0195] Reference is made to Fig. 6 which schematically shows the downlink DL packet processing flow for dual steer PF CP session by a UPF, of some example embodiments.

[0196] As referenced at 600, a packet is received by the UPF.

[0197] As referenced at 602, the UPF determines that a DL packet matches a dual steer PF CP session. This may be based on the target IP address and on dual steer information associated with this target IP address. The UPF performs a look up for the second (that is the linked dual steer session) dual steer PFCP session (if already setup).

[0198] As referenced at 604, the UPF performs a looks up for the DL PDR 606 matching the DL packet with the highest precedence among all DL PDRs of both dual steer PFCP sessions.

[0199] As referenced at 610, the UPF further processes the DL packet according to the packet processing rules 608 associated with this DL PDR. The processing may comprise steering, switching or splitting the traffic according to the dual steer Rules.

[0200] When simultaneous transmission of the two dual steer PDU sessions is supported, different Service Data Flows (SDFs) of the PDU session may be steered to different dual steer PDU sessions, e.g. SDFs A and B steered to the dual steer PDU session 1 and SDFs C and D to the dual steer PDU session 2. When simultaneous transmission of the two dual steer PDU sessions is not supported, all the traffic of the PDU session is transferred on a single dual steer PDU session at any time. The dual steer PDU session used for transferring the traffic may be changed over time. Which dual steer PDU session is to be used may, for example, be defined according to the dual steer rules that the SMF has obtained from the PCF and distributed to the UPF.

[0201] In some example embodiments, a dual steer rule is defined in the PFCP protocol. This may be used in the UPF, as discussed in relation to Fig. 6. This rule may at least support dual steer functionality with simultaneous traffic over the two dual steer PDU sessions.

[0202] The dual steer rule of some example embodiments may indicate how the DL traffic should be steered between the two PDU sessions (e.g. two 3GPP accesses), the steering functionality used (e.g. ATSSS-LL (e.g. access traffic steering, switching, splitting low layer; MPTCP (multi path transmission control protocol), or MPQUIC (multipath QUIC)), and / or the steering mode (e.g. active-standby; smallest delay; load balancing; priority-based; or redundant).

[0203] In some example embodiments, a dual steer rule may enable steering, switching and splitting of DL traffic between two (dual steer) PDU sessions, thus between two 3GPP access paths.

[0204] In some example embodiments, a dual steer rule may be associated with two FARs (forwarding action rule) of the two dual steer PFCP sessions, one FAR per dual steer PFCP session.

[0205] The SMF may provide common packet processing rules (e.g. dual steer rule, QER (quality of service enforcement rules), and / or URR (usage reporting rule) only once to the UPF. The common packet processing rules may be provided via either of the two dual steer PFCP sessions. The common packet processing may be applied by the UPF to both dual steer PFCP sessions. This may be achieved, for example, by associating DL PDRs of both PFCP sessions with these common rules. For example, the DL PDRs of both PFCP sessions may include the dual steer rule ID, QER ID, and / or URR ID. Alternatively, the common packet processing rules may explicitly indicate in the rule that the rule is applicable to any N4 / PDU session of the dual steer grouping.

[0206] The common packet processing rules may be modified or deleted via the same PFCP session that was used to provision them, or alternatively, via the other dual steer PFCP session. When one of the dual steer PDU sessions is deleted, common rules are maintained. Common rules are only deleted when both dual steer PDU sessions are deleted.

[0207] The SMF may, in other example embodiments, provide one or more QERs and / or one or more URRs specific to a given dual steer PDU session. For example, this may allow different QoS requirements for each PDU session / 3GPP access path and / or to support measuring / charging the traffic based on the PDU session / 3GPP access path used to send the traffic.

[0208] These common rules may be modified or deleted via the same PFCP session that was used to provision them, or alternatively, via the other dual steer PFCP session. When one of the dual steer PDU sessions is deleted, common rules are maintained. Common rules may only deleted when both dual steer PDU sessions are deleted.

[0209] The SMF may alternatively provision QERs and URRs specific to a given dual steer PDU session, e.g. to support different QoS requirements for each PDU session / 3GPP access path or to support measuring / charging the traffic based on the PDU session / 3GPP access path used to send the traffic.

[0210] In some example embodiments, where the same SMF establishes the two dual steer PFCP sessions, upon detecting that the SMF serving the dual steer PFCP sessions is no longer responsive, the UPF may move both dual steer PFCP sessions to a same alternative SMF of the SMF set. The UPF may use the dual steer PFCP session indication, the dual steer bundle ID, the dual steer ID and or the linked dual steer ID to assist in moving both dual steer PFCP sessions to a same alternative SMF of the SMF set.

[0211] In some example embodiments, where the different SMFs of the same set are associated with the two dual steer PFCP sessions, upon detecting that one of the SMFs serving one of the dual steer PFCP sessions is no longer responsive, the UPF may move that dual steer PFCP session to the other SMF serving the other dual steer PFCP session. The UPF may use the dual steer PFCP session indication, the dual steer bundle ID, the dual steer ID and or the linked dual steer ID to assist in moving the dual steer PFCP sessions the other SMF.

[0212] In some example embodiments, the same PCF may be selected to control all the dual steer PDU sessions that needs to be bundled. In some example embodiments, there may be one (for example N7) SM policy association per PDU session, This SM policy association may be established when a PDU session is established and released when the PDU session is released. The SMF may provide dual steer related information at SM policy association creati on / modifi cati on .

[0213] In some example embodiments, the SMF may provide to the PCF, for each SM policy association at least one of: an indication that the SM policy association relates to a dual steer PF CP session; a dual steer bundle ID; a dual steer ID (identifier); or a linked dual steer ID set to the dual steer ID of the other dual steer SM policy association.

[0214] In some example embodiments, when the PCF provides PCC rule(s) on an SM policy association, the PCF may indicate whether the PCC rule(s) apply only to the corresponding PDU session or to all PDU sessions in the dual steer bundle.

[0215] In some example embodiments, when one of the dual steer PDU sessions is deleted, common rules may maintained. Common rules may only be deleted when all dual steer PDU sessions in the dual steer bundle are deleted.

[0216] In some example embodiments, this mirrors the SMF behaviour. This may require a simpler SMF behaviour.

[0217] In some example embodiments, as the PDU sessions related to a dual steer bundle and established on a DNN / S-NSSAI combination share the same IP address, the PCF may be able at session binding to retrieve all PDU sessions which are part of the same dual steer bundle.

[0218] In some example embodiments, PCC rule information may indicate how the DL traffic should be steered between the two PDU sessions (e.g. two 3 GPP accesses), the steering functionality used (e.g. ATSSS-LL (e.g. access traffic steering, switching, splitting low layer; MPTCP (multi path transmission control protocol), or MPQUIC (multipath QUIC)), and / or the steering mode (e.g. active-standby; smallest delay; load balancing; priority-based; or redundant). This PCC rule information may at least support dual steer functionality with simultaneous traffic over the two dual steer PDU sessions.

[0219] In some example embodiments, the PCF may, on detecting that the SMF serving a PDU session of a dual steer bundle is no longer responsive, move all SM policy association related to the dual steer bundle to a same alternative SMF of the SMF set. The PCF can use the dual steer related information received at SM Policy Association creation / modification to determine which SM policy associations are impacted. In some example embodiments, the PCF may, where the different SMFs of the same set are associated with the two dual steer PDU sessions, upon detecting that one of the SMFs serving one of the dual steer PFCP sessions is no longer responsive, the PCF may move that the respective SM policy association to the other SMF serving the other dual steer PDU session. The PCF can use the dual steer related information received at SM Policy Association creation / modification to determine which SM policy associations are impacted.

[0220] In some example embodiments, each dual steer PFCP session is provisioned in the UPF with its own user identifier. The user identifier may be the SUPI, for example SUPI-1 and SUPI-2. This may be the case, for example, when policies of a network operator require the user identifier to be sent to the UPF.

[0221] Interception or tracing of UL / DL traffic for a given user identifier, e.g. SUPI, may result in intercepting all the UL / DL traffic exchanged on any of the two dual steer PDU sessions.

[0222] In some example embodiments, each dual steer SM policy association is provisioned in the PCF with its own user identifier. The user identifier may be the SUPI, for example SUPI-1 and SUPI-2.

[0223] Interception or tracing at PCF for a given user identifier, e.g. SUPI, or UE IP address on a DNN / S-NSSAI (single network slice selection assistance information) combination may result in intercepting exchanges related to any of the dual steer PDU sessions in the dual steer bundle.

[0224] Some example embodiments may ensure that a same IP address is used for both of the two dual steer PDU sessions.

[0225] Fig. 4 illustrates an example of an apparatus 201.

[0226] 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.

[0227] 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. In this example, 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 this example 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.

[0228] 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.

[0229] Reference is made to Figs. 7 and 9, which show methods of some example embodiments.

[0230] This method may be performed by an apparatus.

[0231] The apparatus may comprise or implement a session management function.

[0232] The apparatus may comprise suitable means, such as circuitry for providing the method.

[0233] 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.

[0234] Alternatively or additionally, the apparatus may be such as discussed in relation to Fig. 4.

[0235] The method may be provided by computer program code or computer executable instructions.

[0236] Referring to Fig. 7:

[0237] The method may comprise as referenced at Al, sending, to a user plane function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising second dual steer information, said dual steer information comprising dual steer information providing a link to a first packet forwarding control protocol session for a first packet data unit session, the second packet forwarding control protocol session being for a second packet data unit session, said first and second packet data unit sessions supporting dual steering.

[0238] The method may comprise as referenced at A2, receiving, from the user plane function, the same address for the second packet data unit session as for the first packet data unit session, in response to the request to establish or modify the second packet forwarding control protocol session.

[0239] Referring to Fig. 9:

[0240] The method may comprise as referenced at Cl, sending, to a user plane function, a request to establish or modify a first packet forwarding control protocol session, said request to establish or modify the first packet forwarding control protocol session comprising an address to be used for the first packet data unit session, the first packet forwarding control protocol session being associated with a first packet data unit session.

[0241] The method may comprise as referenced at C2, receiving from the user plane function, a response to the request.

[0242] The method may comprise as referenced at C3, sending, to the user plane function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising the address to be used for the second packet data unit session, the same address being used for the second packet data unit session as for the first packet data unit session, said first and second packet data unit sessions being associated packet data unit sessions supporting dual steering.

[0243] The method may comprise as referenced at C4, receiving from the user plane function, a response to the request accepting that the same address is being used for the second packet data unit session.

[0244] Reference is made to Figs. 8, 10 to 13 and 16, which show methods of some example embodiments.

[0245] This method may be performed by an apparatus.

[0246] The apparatus may comprise or implement a user plane function.

[0247] The apparatus may comprise suitable means, such as circuitry for providing the method.

[0248] 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.

[0249] Alternatively or additionally, the apparatus may be such as discussed in relation to Fig. 4.

[0250] The method may be provided by computer program code or computer executable instructions.

[0251] Referring to Fig. 8: The method may comprise as referenced at Bl, receiving, from a session management function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising second dual steer information, said dual steer information comprising dual steer information providing a link to a first packet forwarding control protocol session for a first packet data unit session, the second packet forwarding control protocol session being for a second packet data unit session, said first and second packet data unit sessions being associated packet data unit sessions supporting dual steering.

[0252] The method may comprise as referenced at B2, storing an association between the first and second packet forwarding control protocol sessions.

[0253] The method may comprise as referenced at B3, sending, to the session management function, the same address for the second packet data unit session as for the first packet data unit session, in response to the request.

[0254] Referring to Fig. 10:

[0255] The method may comprise as referenced at DI, receiving, from a session management function, a request to establish or modify a first packet forwarding control protocol session, said request to establish or modify the first packet forwarding control protocol session comprising an address to be used for the first packet data unit session, the first packet forwarding control protocol session being associated with a first packet data unit session.

[0256] The method may comprise as referenced at D2, sending to the session management function, a response to the request.

[0257] The method may comprise as referenced at D3, receiving, from the same or a different session management function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising the address to be used for the second packet data unit session, the same address being used for the second packet data unit session as for the first packet data unit session, said first and second packet data unit sessions being associated packet data unit sessions supporting dual steering.

[0258] The method may comprise as referenced at D4, sending to said same or different session management function, a response to the request accepting that the same address is being used for the second packet data unit session.

[0259] Referring to Fig. 11 : The method may comprise as referenced at El, receiving a packet associated with a first packet forwarding control protocol session.

[0260] The method may comprise as referenced at E2, determining which of packet detection rules associated with the first packet forwarding control protocol session and a second packet forwarding control protocol session, wherein the first and second packet forwarding control protocol sessions are for associated packet data unit sessions supporting dual steering, has a highest precedence.

[0261] The method may comprise as referenced at E3, applying one or more instructions of the packet detection rule with the highest precedence to the packet.

[0262] Referring to Fig. 12:

[0263] The method may comprise as referenced at Fl, determining that a first session management function, serving a first packet data unit session and a second packet data unit session, is no longer able to support the first packet data unit session and the second packet data unit session, the first and second packet data unit sessions being associated packet data unit sessions supporting dual steering.

[0264] The method may comprise as referenced at F2, moving the first and second packet data unit sessions to a second session management function, said second session management function belonging to a same session management function set as the first session management function.

[0265] Referring to Fig. 13:

[0266] The method may comprise as referenced at Gl, determining that a first session management function, serving a first packet data unit session supporting dual steer, is no longer able to support the first packet data unit session.

[0267] The method may comprise as referenced at G2, moving the first packet data unit session to a second session management function, said second session management function supporting a second packet data unit session, the first and second packet data unit sessions supporting dual steering.

[0268] Referring to Fig. 16:

[0269] The method may comprise as referenced at JI, providing a first dual steer packet forwarding control protocol session for a first packet data unit session, the first dual steer packet forwarding control protocol session being associated with a first subscriber identifier associated with a dual steer device. The method may comprise as referenced at J2, providing a second dual steer packet forwarding control protocol session for a second packet data unit session, the second dual steer packet forwarding control protocol session being associated with a second subscriber identifier associated with the dual steer device, said first and second packet data unit sessions supporting dual steering.

[0270] The method may comprise as referenced at J3, intercepting or tracing dual steer traffic using one of said first and second identifiers, to intercept or trace dual steer traffic of both of the first and second packet data unit sessions.

[0271] Reference is made to Figs. 14, 15, 17 and 18, which show methods of some example embodiments.

[0272] This method may be performed by an apparatus.

[0273] The apparatus may comprise or implement a policy control function.

[0274] 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.

[0275] Alternatively or additionally, the apparatus may be such as discussed in relation to Fig. 4.

[0276] The method may be provided by computer program code or computer executable instructions.

[0277] Referring to Fig. 14:

[0278] The method may comprise as referenced at Hl, determining that a first session management function, serving a first packet data unit session and a second packet data unit session, is no longer able to support the first packet data unit session and the second packet data unit session, the first and second packet data unit sessions supporting dual steering.

[0279] The method may comprise as referenced at H2, moving session management policy association for the first and second packet data unit sessions to a second session management function, said second session management function belonging to a same session management function set as the first session management function.

[0280] Referring to Fig. 15:

[0281] The method may comprise as referenced at II, determining that a first session management function, serving a first packet data unit session supporting dual steer, is no longer able to support the first packet data unit session.

[0282] The method may comprise as referenced at 12, moving session management policy association for the first packet data unit session to a second session management function, said second session management function supporting a second packet data unit session, the first and second packet data unit sessions supporting dual steering.

[0283] Referring to Fig. 17:

[0284] The method may comprise as referenced at KI, providing a first session management policy association for a first packet data unit session, the first session management policy association associated with a first subscriber identifier associated with a dual steer device.

[0285] The method may comprise as referenced at K2, providing a second session management policy association for a second packet data unit session, the second session management policy association being associated with a second subscriber identifier associated with the dual steer device, said first and second packet data unit sessions supporting dual steering.

[0286] The method may comprise as referenced at K3, intercepting or tracing dual steer traffic using one of said first and second identifiers, to intercept or trace dual steer traffic of both of the first and second packet data unit sessions.

[0287] Referring to Fig. 18:

[0288] The method may comprise as referenced at LI, based on a common address and / or a common dual steer identifier, retrieving information about a first packet data unit session and a second packet data unit session, said first and second packet data unit sessions together supporting dual steering and binding the information about the first and second packet data unit sessions together to a dual steer bundle.

[0289] It should be appreciated that the method outlined in any one or more of Figs. 7 to 18 may be modified to include any of the previously described features.

[0290] Computer program code may be downloaded and stored in one or more memories of the apparatus described herein.

[0291] 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.

[0292] 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.

[0293] 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.

[0294] 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”).

[0295] 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 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”.

[0296] 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.

[0297] As used herein, the term “circuitry” may refer to one or more or all of the following:

[0298] (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable):

[0299] (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and

[0300] (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

[0301] (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.”

[0302] This definition of circuitry applies to all uses of this term herein, including in any claims. As a further example, as used herein, 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.

[0303] 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 include software code or any portion(s) thereof.

[0304] 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 non-transitory media. 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).

[0305] 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.

[0306] 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.

[0307] 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 their 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: sending, to a user plane function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising second dual steer information, said dual steer information comprising dual steer information providing a link to a first packet forwarding control protocol session for a first packet data unit session, the second packet forwarding control protocol session being for a second packet data unit session, said first and second packet data unit sessions supporting dual steering; and receiving, from the user plane function, the same address for the second packet data unit session as for the first packet data unit session, in response to the request to establish or modify the second packet forwarding control protocol session.

2. The method as claimed in claim 1, comprising, prior to the sending the request to establish or modify the second packet forwarding control protocol session: sending, to the user plane function, a request to establish or modify the first packet forwarding control protocol session, said request to establish or modify the first packet forwarding control protocol session comprising first dual steer information; and receiving, from the user plane function, the address for the first packet data unit session, in response to the request to establish or modify the first packet forwarding control protocol session.

3. The method as claimed in claim 2, comprising: sending, to a policy control function, a request for session management policy association for the first packet data unit session, said request for session management policy association for the first packet data unit session comprising dual steer related information; and receiving, from the policy control function, policy information.

4. The method as claimed in claim 3, wherein the dual steer related information, provided in the request for session management policy association for the first packet data unit session, comprises at least one of:an indicator that the session management policy association is for a dual steer packet data unit session; an identifier of a dual steer bundle of associated packet data unit sessions supporting dual steering; a dual steer identifier for the first session management policy association session; a common dual steer identity for the first session management policy association session and for a second session management policy association associated with the second packet data unit session; a linked dual steer identity of the second session management policy association session; or a session management policy association session identifier of the first session management policy association session.

5. The method as claimed in any preceding claim, comprising: sending, to a policy control function, a request for session management policy association for the second packet data unit session, said request for session management policy association for the second packet data unit session comprising the dual steer related information; and receiving, from the policy control function, policy information.

6. The method as claimed in claim 5, wherein the dual steer related information, provided in the request for session management policy association for the second packet data unit session, comprises at least one of: an indicator that the session management policy association is for a dual steer packet data unit session; an identifier of a dual steer bundle of associated packet data unit sessions supporting dual steering; a dual steer identifier for the second session management policy association session; a common dual steer identity for the first session management policy association session and for the second session management policy association; or a linked dual steer identity of the first session management policy association session; ora session management policy association session identifier of the second session management policy association session.

7. The method as claimed in any of claims 3 to 6, wherein the policy comprises at least one of one or more rules applicable to the first and the second packet data unit sessions; one or more rules applicable to the first packet data unit session; or one or more rules applicable to the second packet data unit session.

8. A method comprising: receiving, from a session management function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising second dual steer information, said dual steer information comprising dual steer information providing a link to a first packet forwarding control protocol session for a first packet data unit session, the second packet forwarding control protocol session being for a second packet data unit session, said first and second packet data unit sessions being associated packet data unit sessions supporting dual steering; storing an association between the first and second packet forwarding control protocol sessions; and sending, to the session management function, the same address for the second packet data unit session as for the first packet data unit session, in response to the request.

9. The method as claimed in claim 8, comprising prior to receiving the request to establish or modify the second packet forwarding control protocol session: receiving, from the same or a different session management function, a request to establish or modify the first packet forwarding control protocol session, said request to establish or modify the first packet forwarding control protocol session comprising first dual steer information; and sending, to the said same or different session management function, the address for the first packet data unit session, in response to the request to establish or modify the first packet forwarding control protocol session.

10. The method as claimed in any preceding claim, wherein the first dual steer information comprises at least one of an indication that the first packet forwarding control protocol session is a packet forwarding control protocol session for a dual steer packet data unit session; an identifier of a dual steer bundle of associated packet data unit sessions supporting dual steering; a dual steer identifier for the first packet forwarding control protocol session; a common dual steer identity for the first and second packet forwarding control protocol sessions; or a linked dual steer identity of the second packet forwarding control protocol session; or a packet forwarding control protocol identifier of the first packet forwarding control protocol session.

11. The method as claimed in any preceding claim, wherein the second dual steer information comprises at least one of an indication that the second packet forwarding control protocol session is a packet forwarding control protocol session for a dual steer packet data unit session; an identifier of a dual steer bundle of associated packet data unit sessions supporting dual steering; a dual steer identifier of the second packet forwarding control protocol session; the common dual steer identity for the first and second packet forwarding control protocol sessions; or a linked dual steer identity of the first packet forwarding control protocol session; or a packet forwarding control protocol identifier of the second packet forwarding control protocol session.

12. The method as claimed in claim 10 or 11, wherein a respective dual steer identifier for a respective session is based on a respective subscriber identifier of a dual steer device and an identifier associated with the respective packet data unit session.

13. The method as claimed in claim 10, 11 or 12, wherein a respective linked dual steer identifier is based on a respective subscriber identifier of a dual steer device and an identifier associated with the respective other packet data unit session.14 The method as claimed in any preceding claim, wherein the request to establish or modify the second packet forwarding control protocol session comprises the address requested to be used by the user plane function for the second packet data unit session.

15. A method comprising: sending, to a user plane function, a request to establish or modify a first packet forwarding control protocol session, said request to establish or modify the first packet forwarding control protocol session comprising an address to be used for the first packet data unit session, the first packet forwarding control protocol session being associated with a first packet data unit session; receiving, from the user plane function, a response to the request; sending, to the user plane function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising the address to be used for the second packet data unit session, the same address being used for the second packet data unit session as for the first packet data unit session, said first and second packet data unit sessions being associated packet data unit sessions supporting dual steering; and receiving, from the user plane function, a response to the request accepting that the same address is being used for the second packet data unit session.

16. A method comprising: receiving, from a session management function, a request to establish or modify a first packet forwarding control protocol session, said request to establish or modify the first packet forwarding control protocol session comprising an address to be used for the first packet data unit session, the first packet forwarding control protocol session being associated with a first packet data unit session; sending, to the session management function, a response to the request;receiving, from the same or a different session management function, a request to establish or modify a second packet forwarding control protocol session, said request to establish or modify the second packet forwarding control protocol session comprising the address to be used for the second packet data unit session, the same address being used for the second packet data unit session as for the first packet data unit session, said first and second packet data unit sessions being associated packet data unit sessions supporting dual steering; and sending, to said same or different session management function, a response to the request accepting that the same address is being used for the second packet data unit session.

17. The method as claimed in claim 15 or claim 16 wherein the request to establish or modify the second packet forwarding control protocol session comprises an indication that the second packet forwarding control protocol session is for a dual steer packet data unit session.

18. The method as claimed in any preceding claim, wherein the same address comprises an IP address, an internet protocol IP address prefix or a media access control MAC address.

19. The method as claimed in any preceding claim, wherein the same address comprises an address associated with dual steer device supporting dual steering.

20. The method as claimed in any of claims 1 to 7, 10 to 15 and 17 to 19, comprising providing the user plane function with one or more packet processing rules, wherein the one or more packet processing rules comprise at least one of: one or more rules applicable to the first and the second packet forwarding control protocol sessions; one or more rules applicable to the first packet forwarding control protocol session; or one or more rules applicable to the second packet forwarding control protocol session.

21. A computer program comprising computer executable instructions which when run provide one of the methods of any of claims 1 to 20.

22. An apparatus comprising means for performing the method of any one of claims 1 to 20.

23. An apparatus comprising 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 of any one of claims 1 to 20.

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