UE-satellite-UE communication

Abstract

There are provided measures for (e.g. enabling / facilitating / realizing enhancements and / or improvements for) management / control of UE-satellite-UE communication, i.e. a satellite communication between a first user equipment and a second user equipment. Such measures may, for example, comprise that a network function, element or entity, such as e.g. a P-CSCF, requests, for a call between a first user equipment and a second user equipment via a satellite communication, insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, obtains the addressing information for the local breakout point, and provides the addressing information for the local breakout point towards a network entity of a network serving the second user equipment.

Description

UE-SATELLITE-UE COMMUNICATIONTECHNICAL FIELD

[0001] This disclosure generally refers to mobile or wireless communication technology and systems. Various example embodiments relate to measures / mechanisms (including, e.g. methods, apparatuses and computer program products) for (e.g. enabling or otherwise facilitating or realizing enhancements and / or improvements for) managem ent / control of UE- satellite-UE communication, i.e. a satellite communication between a first user equipment and a second user equipment.BACKGROUND

[0002] Examples of mobile or wireless communication technology and systems may include fifth generation (5G), sixth generation (6G) and / or new radio (NR). Fifth generation (5G) and sixth generation (6G) wireless systems refer to the next generation (NG) of radio systems and network architecture. 5G and 6G network technology is based on new radio (NR) technology, but the 5G / 6G (or NG) network can also build on E-UTRAN radio. It is estimated that NR may provide bitrates on the order of 10-20 Gbit / s or higher and may support at least enhanced mobile broadband (eMBB) and ultra-reliable low-latency communication (URLLC) as well as massive machine-type communication (mMTC). NR is expected to deliver extreme broadband and ultra-robust, low-latency connectivity and massive networking to support the Internet of Things (loT).

[0003] Such mobile or wireless communication technology and systems may support (communication via) non-terrestrial networks (NTNs), i.e. any network that involves nonterrestrial flying objects. Satellite-based communication can potentially play an important role in leveraging communication infrastructure for 5G / 6G / NR services. By use of NTN, UE- satellite-UE communication, i.e. a satellite communication between a first user equipment and a second user equipment, can be realized.LIST OF ACRONYMS AND ABBREVIATIONS 3GPP 3rd Generation Partnership Project5G Fifth Generation6G Sixth GenerationAAA Authorization Authentication AnswerAAR Authorization Authentication RequestAF Application FunctionAGW Access GatewayAMF Access and Mobility Management FunctionANI Access Network InformationAPI Application Programming InterfaceDL DownlinkEPS Evolved Packet SystemFAR Forwarding Action RuleGRE Generic Routing EncapsulationHSS Home Subscriber ServerI / S-CSCF Interrogating / Serving Call Session Control FunctionI-UPF Intermediate User Plane FunctionIBCF Interconnection Border Control FunctionIMS IP Multimedia SubsystemIP Internet ProtocolISL Inter-Satellite LinkL2TP Layer 2 Tunneling ProtocolL-PSA Local PDU Session AnchorMMTel Multimedia TelephonyN3IW Non-3GPP InterWorking FunctionNAS Non-Access StratumNAS-MM NAS Mobility ManagementNAS-SM NAS Session ManagementNPLI Network Provided Location InformationNTN Non-T erre stri al N etworkP-CSCF Proxy Call Session Control FunctionPANI P-Access-Network-InfoPCC Policy and Charging ControlPCF Policy Control FunctionPDU Packet Data UnitPDR Packet Detection RulePMIP Proxy Mobile Internet ProtocolPSA PDU Session AnchorPtP Point-to-PointQoS Quality of ServiceRAA Re-Authorization AnswerRAN Radio Access NetworkRAR Re-Authorization RequestSDF Service data FlowSDN Software Defined NetworkingSDP Session Description ProtocolSIP Session Initiation ProtocolSMF Session Management FunctionTAS Telephony Application ServerTNGF Trusted Non-3GPP Gateway FunctionTrGW Transition GatewayUDM Unified Data ManagementUDP User Datagram ProtocolUE User EquipmentUPF User Plane FunctionUL UplinkUL-CL Uplink ClassifierURI Uniform Resource IdentifierW-AGF Wireless Access Gateway FunctionSUMMARY

[0004] Various example embodiments address at least part of issues, problems and / or drawbacks described herein or otherwise recognized by a person skilled in the art in view of this disclosure.

[0005] Various example embodiments are set out in the claims.

[0006] Some of the various example embodiments are described with respect to certain aspects. These aspects are not intended to indicate key or essential features of the various example embodiments, nor are they intended to be used to limit the scope of thereof. Other features, aspects, and elements will be recognized by a person skilled in the art in view of this disclosure.

[0007] According to an example aspect, there is provided a method, comprising: requesting, for a call between a first user equipment and a second user equipment via a satellite communication, insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, obtaining the addressing information for the local breakout point, and providing the addressing information for the local breakout point towards a network entity of a network serving the second user equipment.

[0008] According to an example aspect, there is provided an apparatus, comprising: means for requesting, for a call between a first user equipment and a second user equipment via a satellite communication, insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, means for obtaining the addressing information for the local breakout point, and means for providing the addressing information for the local breakout point towards a network entity of a network serving the second user equipment.

[0009] According to an example aspect, there is provided 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: request, for a call between a first user equipment and a second user equipment via a satellite communication, insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, obtain the addressing information for the local breakout point, and provide the addressing information for the local breakout point towards a network entity of a network serving the second user equipment.

[0010] According to an example aspect, there is provided an apparatus, comprising: one more circuitry configured to request, for a call between a first user equipment and a second user equipment via a satellite communication, insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, obtain the addressing information for the local breakout point, and provide the addressing information for the local breakout point towards a network entity of a network serving the second user equipment.

[0011] According to various developments / modifications, any one of the aforementioned method-related and / or apparatus-related example aspects may include one or more of the following features:the method, functionality, operability or configuration comprises or enables: invoking policy control function services including authorization of resources for the call and (together with) insertion of the local breakout point for the call, the insertion of a local breakout point and the report of addressing information for the local breakout point are requested at a policy control function of a network serving the first user equipment, the addressing information for the local breakout point is obtained from a policy control function of a network serving the first user equipment, the method, functionality, operability or configuration comprises or enables: sending, towards a proxy call session control function of the network serving the second user equipment, a message including the addressing information for the local breakout point, wherein the addressing information for the local breakout point may be contained in a session initiation protocol message or a session initiation protocol header or a session description protocol message, and / or the addressing information for the local breakout point may be contained in a P -Access-Network-Info header, the method, functionality, operability or configuration comprises or enables: obtaining addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the second user equipment, and providing the addressing information for the remote breakout point towards at least one network entity of a network serving the first user equipment, the method, functionality, operability or configuration comprises or enables: receiving, from a proxy call session control function of the network serving the second user equipment, a message including the addressing information for the remote breakout point, wherein the addressing information for the remote breakout point may be contained in a session initiation protocol message or a session initiation protocol header or a session description protocol message, and / or the addressing information for the remote breakout point may be contained in a P-Access-Network-Info header, the method, functionality, operability or configuration comprises or enables: invoking policy control function services including authorization of resources for the call in accordance with the addressing information for the remote breakout point, the method, functionality, operability or configuration comprises or enables: obtaining addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the first user equipment, wherein the requesting comprises requesting insertionof the local breakout point for the call in accordance with the addressing information for the remote breakout point, the method, functionality, operability or configuration comprises or enables: invoking policy control function services including authorization of resources for the call and (together with) insertion of the local breakout point for the call in accordance with the addressing information for the remote breakout point, the addressing information of a breakout point for the call is or comprises an IP address of a tunnel endpoint of a tunnel for transferring one or more media or service data flows of the call in the satellite communication, the tunnel is or comprises a point-to-point tunnel, the tunnel endpoint is or comprises an intermediate user plane function at the satellite providing connectivity for the respective user equipment, the satellite communication is or comprises call-related communication in an IP network in a single satellite, a single satellite constellation or across multiple satellite constellations, the first user equipment comprises a local user equipment served by a first network comprising a network entity performing the method, the second user equipment comprises a remote user equipment served by a second network, the first user equipment comprises an originating or calling party of the call and the second user equipment comprises a terminating or called party of the call, or the second user equipment comprises an originating or calling party of the call and the first user equipment comprises a terminating or called party of the call, the local breakout point is or comprises an intermediate user plane function at the satellite providing connectivity for the first user equipment, each one of the first network and the second network is or comprises an IP multimedia subsystem, the call is an IP multimedia subsystem call or a multimedia telephony call. the method is operable by or at or the apparatus is (operated or located) in or at a proxy call session control function, and / or the method is performed or the apparatus is configured to operate during or as part of an IP multimedia subsystem session and / or call or an establishment procedure thereof.

[0012] According to an example aspect, there is provided a method, comprising: obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, inserting the local breakout point for the call relating to the satellite providing connectivity for the first user equipment, retrieving the addressing information for the local breakout point, and reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0013] According to an example aspect, there is provided an apparatus, comprising: means for obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, means for inserting the local breakout point for the call relating to the satellite providing connectivity for the first user equipment, means for retrieving the addressing information for the local breakout point, and means for reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0014] According to an example aspect, there is provided 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: obtain, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, insert the local breakout point for the call relating to the satellite providing connectivity for the first user equipment, retrieve the addressing information for the local breakout point, and report the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0015] According to an example aspect, there is provided an apparatus, comprising: one more circuitry configured to obtain, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, insert the local breakout point for the call relating to the satellite providing connectivity for the first user equipment, retrieve theaddressing information for the local breakout point, and report the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0016] According to various developments / modifications, any one of the aforementioned method-related and / or apparatus-related example aspects may include one or more of the following features: the request is obtained via policy control function services and / or rules, including policy and charging control rules, for the call from a policy control function of the network serving the first user equipment, the addressing information for the local breakout point is reported to a policy control function of the network serving the first user equipment, the method, functionality, operability or configuration comprises or enables: allocating one or more intermediate user plane functions at the satellite providing connectivity for the first user equipment, and configuring the one or more intermediate user plane functions to act as a local packet data unit session anchor, wherein the addressing information for the local breakout point is retrieved from the local packet data unit session anchor, the addressing information for the local breakout point is retrieved based on a packet detection rule and / or forwarding action rule with outer header creation request, the method, functionality, operability or configuration comprises or enables: obtaining a request for updating the local breakout point for the call in accordance with addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the second user equipment, and updating a local packet data unit session anchor, corresponding to the local breakout point relating to the satellite providing connectivity for the first user equipment, in accordance with the addressing information for the remote breakout point for the call, the request is obtained via an update of rules, including policy and charging control rules, for the call from a policy control function of a network serving the first user equipment, the updating comprises providing the addressing information for the remote breakout point for the call, the obtaining comprises obtaining a request for insertion of the local breakout point for the call in accordance with addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the first user equipment,the inserting comprises inserting the local breakout point for the call relating to the satellite providing connectivity for the first user equipment in accordance with the addressing information for the remote breakout point for the call, the addressing information of a breakout point for the call is or comprises an IP address of a tunnel endpoint of a tunnel for transferring one or more media or service data flows of the call in the satellite communication, the tunnel is or comprises a point-to-point tunnel, the tunnel endpoint is or comprises an intermediate user plane function at the satellite providing connectivity for the respective user equipment, the satellite communication is or comprises call-related communication in an IP network in a single satellite, a single satellite constellation or across multiple satellite constellations, the first user equipment comprises a local user equipment served by a first network comprising a network entity performing the method, the second user equipment comprises a remote user equipment served by a second network, the first user equipment comprises an originating or calling party of the call and the second user equipment comprises a terminating or called party of the call, or the second user equipment comprises an originating or calling party of the call and the first user equipment comprises a terminating or called party of the call, the local breakout point is or comprises an intermediate user plane function at the satellite providing connectivity for the first user equipment, each one of the first network and the second network is or comprises an IP multimedia subsystem, the call is an IP multimedia subsystem call or a multimedia telephony call, the method is operable by or at or the apparatus is (operated or located) in or at a session management function, the method is performed or the apparatus is configured to operate during or as part of an IP multimedia subsystem session and / or call or an establishment procedure thereof.

[0017] According to an example aspect, there is provided a method, comprising: obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for report of addressing information for a local breakout point for the call relating to a satellite providing connectivity for the first user equipment, and reportingthe addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0018] According to an example aspect, there is provided an apparatus, comprising: means for obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for report of addressing information for a local breakout point for the call relating to a satellite providing connectivity for the first user equipment, and means for reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0019] According to an example aspect, there is provided 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: obtain, for a call between a first user equipment and a second user equipment via a satellite communication, a request for report of addressing information for a local breakout point for the call relating to a satellite providing connectivity for the first user equipment, and report the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0020] According to an example aspect, there is provided an apparatus, comprising: one more circuitry configured to obtain, for a call between a first user equipment and a second user equipment via a satellite communication, a request for report of addressing information for a local breakout point for the call relating to a satellite providing connectivity for the first user equipment, and report the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0021] According to various developments / modifications, any one of the aforementioned method-related and / or apparatus-related example aspects may include one or more of the following features: the method, functionality, operability or configuration comprises or enables: obtaining a packet detection rule and / or forwarding action rule with outer header creation request, wherein the reporting comprises reporting addressing information corresponding to the outer header being created in response to the outer header creation request, the method is operable by or at or the apparatus is (operated or located) in or at a user plane function and / or an intermediate user plane function at the satellite providing connectivity for the first user equipment, the method is performed or the apparatus is configured to operate during or as part of an IP multimedia subsystem session and / or call or an establishment procedure thereof.According to an example aspect, there is provided a method, comprising: obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, provisioning rules, including policy and charging control rules, for the call with regard to the request for insertion of the local breakout point for the call, obtaining the addressing information for the local breakout point, and reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0022] According to an example aspect, there is provided an apparatus, comprising: means for obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, means for provisioning rules, including policy and charging control rules, for the call with regard to the request for insertion of the local breakout point for the call, means for obtaining the addressing information for the local breakout point, and means for reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0023] According to an example aspect, there is provided 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: obtain, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, provision rules, including policy and charging control rules, for the call with regard to the request for insertion of the local breakout point for the call, obtain the addressing information for the local breakout point, and report the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0024] According to an example aspect, there is provided an apparatus, comprising: one more circuitry configured to obtain, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, provision rules, including policy andcharging control rules, for the call with regard to the request for insertion of the local breakout point for the call, obtain the addressing information for the local breakout point, and report the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0025] According to various developments / modifications, any one of the aforementioned method-related and / or apparatus-related example aspects may include one or more of the following features: the method, functionality, operability or configuration comprises or enables: initiating policy control function services including authorization of resources for the call and (together with) insertion of the local breakout point for the call, the addressing information for the local breakout point is obtained from a session management function of the network serving the first user equipment, the addressing information for the local breakout point is reported towards a proxy call session control function of the network serving the first user equipment, the method, functionality, operability or configuration comprises or enables: obtaining a request for authorization of resources for the call, in accordance with addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the second user equipment, and updating the rules, including the policy and charging control rules, for the call in accordance with addressing information for the remote breakout point, the request comprises a request for insertion of the local breakout point for the call in accordance with addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the second user equipment, the first user equipment is a local user equipment served by a first network comprising a network entity performing the method, the second user equipment comprises a remote user equipment served by a second network the first user equipment comprises an originating or calling party of the call and the second user equipment comprises a terminating or called party of the call, or the second user equipment comprises an originating or calling party of the call and the first user equipment comprises a terminating or called party of the call, the local breakout point is or comprises an intermediate user plane function at the satellite providing connectivity for the first user equipment,each one of the first network and the second network is or comprises an IP multimedia subsystem, the call is an IP multimedia subsystem call or a multimedia telephony call, the method is operable by or at or the apparatus is (operated or located) in or at a policy control function, the method is performed or the apparatus is configured to operate during or as part of an IP multimedia subsystem session and / or call or an establishment procedure thereof.

[0026] According to an example aspect, there is provided a system comprising at least two of the apparatuses according to any one of the aforementioned apparatus-related example aspects (and / or any development / modification thereof).

[0027] According to an example aspect, there is provided a computer-readable medium comprising program instructions for causing an apparatus (e.g. an apparatus according to any one of the aforementioned apparatus-related example aspects (and / or any development / modification thereof)) to perform at least a method according to any one of the aforementioned method-related example aspects (and / or any development / modification thereof).

[0028] According to an example aspect, there is provided a computer program product comprising (computer-executable) computer program code which, when the program code is executed (or run) on a computer or the program is run on a computer (e.g. a computer of an apparatus according to any one of the aforementioned apparatus-related example aspects (and / or any development / modification thereof)), is configured to cause the computer to carry out at least a method according to any one of the aforementioned method-related example aspects (and / or any development / modification thereof).

[0029] The computer program product may comprise or may be embodied as a (tangible / non- transitory) computer-readable (storage) medium or the like, on which the computer-executable computer program code is stored, and / or the program is directly loadable into an internal memory of the computer or a processor thereof.

[0030] The term “non-transitory,” as used herein, is a limitation of the medium itself (referring to e.g. a tangible medium, not a signal) as opposed to a limitation on data storage persistency (e g. RAM vs. ROM).

[0031] Further developments and / or modifications of the aforementioned example aspects are set out in the following.

[0032] By way of example embodiments, technique(s) for (e.g. enabling or otherwise facilitating or realizing enhancements and / or improvements for) managem ent / control of UE- satellite-UE communication, i.e. a satellite communication between a first user equipment and a second user equipment, may be provided.

[0033] This summary is intended to provide a brief overview of some of the aspects (and features thereof) according to the various example embodiments of the disclosure. Accordingly, it will be appreciated that the above-described aspects (and features thereof) are merely examples and should not be construed to narrow the scope of the various example embodiments or disclosure in any way. Other features, aspects, and advantages of the disclosure will become apparent from the following detailed description, drawings and claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In the following, various example embodiments will be described with reference to the accompanying drawings, in which:

[0035] FIG. 1 shows a schematic diagram of an example system configuration for UE-satellite- UE communication;

[0036] FIGs. 2 to 8 each show a flowchart of an example method or process;

[0037] FIGs. 9 to 10 each show an example procedure;

[0038] FIG. 11 shows an example IMS session establishment procedure at a terminating side of an IMS call;

[0039] FIG. 12 shows an example IMS session establishment procedure at an originating side of an IMS call;

[0040] FIG. 13 (including FIGs. 13 A and 13B) shows an example end-to-end IMS session establishment procedure;

[0041] FIG. 14 shows a schematic block diagram of a structure of apparatuses;

[0042] FIG. 15 shows a schematic block diagram of a structure of apparatuses.DETAILED DESCRIPTION

[0043] Various example embodiments are herein described with reference to particular nonlimiting and illustrative examples. A person skilled in the art will appreciate that these various example embodiments are by no means limited to these non-limiting and illustrative examples, and may be more broadly applied.

[0044] References in the specification to "one embodiment," "an embodiment," "an example embodiment," "some example embodiments," "certain example embodiments," "various example embodiments," and so forth, indicate that the referenced embodiment s) may include particular feature(s), structure(s), or character! stic(s), but every referenced embodiment or example embodiment may not necessarily include the particular feature(s), structure(s), or character! stic(s). Moreover, such phrases are not necessarily referring to the same embodiment or example embodiment. Further, when particular feature(s), structure(s), or characteristic(s) are described in connection with an embodiment or an example embodiment, it is submitted that it is within the knowledge of one skilled in the art to implement such feature, structure, or characteristic in connection with any other embodiments or example embodiments whether or not such combination(s) are explicitly described.

[0045] It is to be noted that the detailed description, at times, refers to one or more specifications being used as non-limiting and illustrative examples for certain architectures, network configurations and system deployments. More specifically, the detailed description makes reference to 3GPP standards, being used as non-limiting and illustrative examples. As such, the example embodiments provided herein can specifically employ terminology which is directly related thereto. Such terminology is only used in the context of the non-limiting and illustrative examples, and is not intended to limit the example embodiments in any way. Rather, any other system configuration or deployment may be utilized while complying with what is described herein and / or example embodiments are applicable to it.

[0046] For example, various example embodiments are applicable in any (e.g., mobile / wireless) communication system, such as a 5G / NR system and a next-generation / future system beyond 5G. For example, various example embodiments are applicable in a 3GPP- standardized mobile / wireless communication system of Release 18 / 19 onwards. Furthermore, even though reference to 5G / NR is made, other types of access / system / network are supported / covered as well, such as future 3GPP radio / 6G but also non-3GPP access to 3GPP Core (such as e.g. Untrusted non-3GPP access to 3GPP core using e.g. N3IWF, Trusted non- 3GPP access to 3GPP core using e.g. TNGF, wireline access to 3GPP core using e.g. W-AGF), or the like.

[0047] When reference is made to particular terminology specific for any such example system, these references are to be understood / construed to be more generally applicable in a corresponding, similar or equivalent meaning. More specifically, when reference is made to some network function, entity or element of a 5G / NR or 3GPP system, it shall beunderstood / construed that any network function, entity or element of any system is meant or encompassed, which has or exhibits a corresponding, similar or equivalent characteristic, functionality, purpose or the like. As an illustrative but non-exhaustive example, a reference to P-CSCF, PCF or SMF shall mean or encompass any network function, entity or element of any communication network, which has or exhibits a characteristic, functionality, purpose or the like, which is corresponding, similar or equivalent to that of the referenced P-CSCF, PCF or SMF, respectively.

[0048] Hereinafter, various example embodiments are described using several variants and / or alternatives. It is generally to be noted that, according to certain implementations or constraints, all of the described variants and / or alternatives may be provided alone or in any conceivable combination (e.g. also including combinations of individual features of these various variants and / or alternatives).

[0049] As used herein, the words “comprising” and “including” should be understood as not limiting the example embodiments to consist of only those features that have been mentioned, and example embodiments may also contain, among other things, e.g. features, structures, units, modules, or the like, that have not been specifically mentioned.

[0050] As used herein, “at least one of the following: ” and “at least one of ” and similar expressions, like “one or more of’, 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. As used herein, the expression “and / or” mean at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0051] As used herein, unless to explicitly stated to the contrary, performing a step / operation / functionality “in response to A” does not indicate that the step / operation / functionality is performed immediately after “A” occurs as one or more intervening steps / operations / functionalities may be included therebetween. Analogously, performing a step / operation / functionality “based on A” does not indicate that the step / operation / functionality is performed solely based on “A”, as the referenced step / operation / functionality may be further based on one or more other conditions (such as “B”) in addition to “A”.

[0052] As used herein, according to various example embodiments, any operations of sending or receiving may comprise actual transmission or communication operations, e.g. transmitting or communicating associated information, data, signals or messages, but may additionally oralternatively comprise related processing operations, e.g. preparing / generating / issuing associated information, data, signals or messages before sending and / or obtaining / handling / processing of associated information, data, signals or messages after receiving. For example, sending an information or data at / by a node may comprise generating / issuing and / or transmitting / communicating thereof or a corresponding signal or message in / at / by the node, and receiving a signal or message at / by a node may comprise obtaining / handling and / or processing thereof or a corresponding information or data in / at / by the node. As used herein, a signal or message may refer to and / or encompass any kind of corresponding information, data, signal or the like.

[0053] In the drawings, it is to be noted that lines / arrows interconnecting individual blocks or entities are generally meant to illustrate an operational coupling there-between, which may be a physical and / or logical coupling, which on the one hand is implementation-independent (e.g. wired or wireless) and on the other hand may also comprise an arbitrary number of intermediary functional blocks or entities not shown. In flowcharts or sequence diagrams, the illustrated order of operations or actions is generally non-limiting and illustrative, and any other order of respective operations or actions is conceivable, if feasible.

[0054] It should be noted that all concepts described herein, although described in a specific manner or context, may be more generally applicable, e.g. in another specific manner or context, as will be apparent to the skilled person.

[0055] Various example embodiments relate to considerations in a (e.g. mobile / wireless) communication system or network, such as a 5G / NR system and a next-generation / future system beyond 5G. For example, various example embodiments are applicable in a 3GPP- standardized mobile / wireless communication system or network of Release 18 / 19 onwards. Such considerations relate to (managem ent / control of) UE-satellite-UE communication, i.e. a satellite communication between a first user equipment and a second user equipment.

[0056] For a UE-satellite-UE deployment in / with (3GPP -based) mobile or wireless communication technology and systems, an IMS(-based) solution is usable. That is, IMS architecture and / or procedures may be enhanced to support UE-satellite-UE communication. For support of a UE-satellite-UE scenario in NTN, e.g. a UE-satellite-UE communication for an IMS / MMTel call or service, there are various challenges, e.g. including the following:- How to ensure routing of IMS user plane traffic remains in the satellite.- Potential impacts on IMS procedures and functions to manage UE-satellite-UE communication.- Minimize service interruption if the serving satellite changes.

[0057] For UEs being served by satellite access in regenerative architecture (i.e. RAN on-board satellite), the delay due to a longer transmission path between the satellite and ground station is significantly high. In such architecture, the voice telephony services will not only occupy critical satellite bandwidth but also suffer quality issues due to longer path delays. The effective way for UEs under satellite access is to offload user plane traffic via satellite by avoiding IMS U-plane traffic handling at the ground.

[0058] Accordingly, there is room for enhancement and / or improvement (e.g. by addressing one or more of the above challenges) in this regard, and the technique(s) disclosed herein refers to at least part of such aspects, issues or considerations which are exemplified in the context of IMS architecture and / or procedures in the framework of a 5G / NR system.

[0059] When herein reference is made to satellite communication between two user equipments (UEs) or UE-satellite-UE communication, this is meant to refer to a communication (of user plane traffic) which takes place via one or more satellites or satellite constellations, without any terrestrial transmission. With reference to FIG. 1, a satellite communication or UE-satellite-UE communication could thus be a communication / transmission from the left-hand UE to the right-hand UE via (the RAN and I- UPF of) the left-hand satellite, the PtP tunnel and (the RAN and I-UPF of) the right-hand satellite, or vice versa.

[0060] FIG. 1 shows a schematic diagram of an example system configuration for UE-satellite- UE communication.

[0061] As shown in FIG. 1, the system configuration is composed of two portions on the lefthand side and the right-hand side of the dash-dotted line, each portion comprising terrestrial, ground or earth-bound components depicted in the lower part of FIG. 1 and non-terrestrial, airborne or satellite-based components depicted in the upper part of FIG. 1. In each of the system portions, a UE is served by a (terrestrial, ground or earth-bound) network, which may comprise 5G / NR network functions, entities or elements and IMS network functions, entities or elements. For example, UPF, PCF, SMF, AMF, UDM represent the 5G / NR network, while P-CSCF, I / S-CSCF, TAS, IBCF and HSS represent the IMS network. Further, the UE may be provided with (non-terrestrial, airborne or satellite-based) UE connectivity via satellite access by a satellite which may comprise a (regenerative) RAN and a UPF, such as an I-UPF, relating to the 5G / NR network. A PtP N6 tunnel (providing N6 PtP tunneling e.g. based on IP over IP,UDP / IPv6, PMIP / GRE or L2TP) may be established between satellites (of the same satellite constellation or different satellite constellations) providing connectivity for the UEs.

[0062] When an IMS / MMTel call or service is being established or is (to be) established between the two UEs (, control plane traffic may be exchanged via the respective 5G / NR and IMS networks (i.e. via the network functions, entities or elements in the lower part of FIG. 1, while it is noted that the connections between these network functions, entities or elements is illustrative and does not necessarily show a particular signaling path), and use plane traffic may be exchanged via the respective satellites (i.e. via the network functions, entities or elements and the tunnel in the upper part of FIG. 1). That is, as mentioned above, user plane traffic may be offloaded to satellite communication, i.e. UE-satellite-UE communication. Even though the description refers to establishment of an IMS call, it may apply during such a call, e.g. when one of the peers of such call moves from a situation where it is not served by a satellite with satellite offloading capability to a situation where it is served by a satellite with satellite offloading capability.

[0063] Hereinafter, the UE and all network functions, entities or elements in the same portion of the system configuration are considered to be “local”, while, from the perspective of the UE and any network function, entity or element in one portion of the system configuration, the UE and all network functions, entities or elements in the other portion of the system configuration are considered to be “remote”. For example, when establishing an IMS / MMTel call or service between the two UEs, for the UE or any network function, entity or element at the originating side, the UE or all network functions, entities or elements at the originating side are local, while the UE and all network functions, entities or elements at the terminating side are remote, and vice versa.

[0064] It is to be noted that an (IMS / MMTel) call relates to and / or is using on a corresponding (PDU) session for IMS / MMtel services (while the (PDU) session exists independently of the call). The (PDU) session is to carry call media (e.g. voice packets), IP / media flows, or the like. For the call-related and / or IMS-related (PDU) session, it is assumed that any involved UE gets an IP address from a PSA UPF (located in the ground network), and registers onto the (IMS) network with this fixed IP address (related to the ground network PSA UPF). Thus, the UEs involved in a (IMS) call keep their IP addresses unchanged and do not need to re-register at the (IMS) network when changing the serving satellite.

[0065] Example embodiments relate to managem ent / control of UE-satellite-UE communication (i.e. user plane traffic offloading). As detailed below, example embodimentscan facilitate (how) to manage / control call / session establishment using an IP network, which is built by an ISL (Inter Satellite Link) or set of ISLs at asatellite constellation or possibly between satellite constellation(s) and provides for possible local or satellite traffic switching, for the transfer of user plane traffic of a call. Thereby, it can be achieved that user plane traffic offloading is carried out for a call with the involved parties being under coverage with a suitable regenerative satellite or satellite constellation(s).

[0066] It is to be noted that user plane traffic (offloading) may be referred to as IMS user plane traffic (offloading).

[0067] As noted above, the ISL or set of ISL (inter-satellite links) at satellite constellation(s) is assumed to build an IP network. When parties involved in an IMS call / session are served by satellites that can exchange user plane traffic over ISL(s), this user plane traffic is tunneled between local UPFs located on these satellites. Example embodiments provide for techniques to define how IMS entities can exchange tunnel information and control the UPF via PCF and SMF for the I-UPF on satellite to send IMS user flows on proper tunnels over ISL links.

[0068] FIG. 2 shows a flowchart of an example method or process according to at least one example embodiment. This example method or process may be performed or carried out at / by an apparatus. The apparatus may implement (at least in part) or, stated in other words, the method or process may be a method or process of (or, stated in other words, operable or for use in / by) a P-CSCF as an example of a network function, entity or element of a communication system. The P-CSCF may be at the originating side or the terminating side of a call (which may be ongoing or may be to be established or under establishment).

[0069] As shown in FIG. 2, the method or process comprises a step / operation (SI 10) of requesting, for a call between a first user equipment and a second user equipment via a satellite communication, insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, a step / operation (S120) of obtaining the addressing information for the local breakout point, and a step / operation (S130) of providing the addressing information for the local breakout point towards a network entity of a network serving the second user equipment.

[0070] The request in step / operation SI 10 may be or comprise a request for invoking policy control function services (i.e. a PCF request) including authorization of resources for the call and (together with) insertion of the local breakout point for the call. Such request may request at the PCF invoking of corresponding policy control function services.

[0071] As indicated by dashed lines, the method or process may further comprises a step / operation (S140) of obtaining addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the second user equipment, and a step / operation (SI 50) providing the addressing information for the remote breakout point towards at least one network entity of a network serving the first user equipment.

[0072] FIG. 3 shows a flowchart of an example method or process according to at least one example embodiment. This example method or process may be performed or carried out at / by an apparatus. The apparatus may implement (at least in part) or, stated in other words, the method or process may be a method or process of (or, stated in other words, operable or for use in / by) a P-CSCF as an example of a network function, entity or element of a communication system. The P-CSCF may be at the originating side of a call (which may be ongoing or may be to be established or under establishment).

[0073] As shown in FIG. 3, the method or process comprises a step / operation (S210) of obtaining addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the first user equipment, a step / operation (S220) of requesting, for a call between a first user equipment and a second user equipment via a satellite communication, insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment in accordance with the addressing information for the remote breakout point and report of addressing information for the local breakout point, a step / operation (S230) of obtaining the addressing information for the local breakout point, and a step / operation (S240) of providing the addressing information for the local breakout point towards a network entity of a network serving the second user equipment.

[0074] The request in step / operation S220 may be or comprise a request for invoking policy control function services (i.e. a PCF request) including authorization of resources for the call in accordance with the addressing information for the remote breakout point. Such request may request at the PCF invoking of corresponding policy control function services.

[0075] FIG. 4 shows a flowchart of an example method or process according to at least one example embodiment. This example method or process may be performed or carried out at / by an apparatus. The apparatus may implement (at least in part) or, stated in other words, the method or process may be a method or process of (or, stated in other words, operable or for use in / by) a SMF as an example of a network function, entity or element of a communication system. The SMF may be at the originating side or the terminating side of a call (which may be ongoing or may be to be established or under establishment).

[0076] As shown in FIG. 4, the method or process comprises a step / operation (S310) of obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, a step / operation (S320) of inserting the local breakout point for the call relating to the satellite providing connectivity for the first user equipment, a step / operation (S330) of retrieving the addressing information for the local breakout point, and a step / operation (S340) of reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0077] As indicated by dashed lines, the method or process may further comprises a step / operation (S350) of obtaining a request for updating the local breakout point for the call in accordance with addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the second user equipment, and a step / operation (S360) of updating a local packet data unit session anchor, corresponding to the local breakout point relating to the satellite providing connectivity for the first user equipment, in accordance with the addressing information for the remote breakout point for the call.

[0078] FIG. 5 shows a flowchart of an example method or process according to at least one example embodiment. This example method or process may be performed or carried out at / by an apparatus. The apparatus may implement (at least in part) or, stated in other words, the method or process may be a method or process of (or, stated in other words, operable or for use in / by) a SMF as an example of a network function, entity or element of a communication system. The SMF may be at the originating side of a call (which may be ongoing or may be to be established or under establishment).

[0079] As shown in FIG. 5, the method or process comprises a step / operation (S410) of obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment in accordance with addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, a step / operation (S420) of inserting the local breakout point for the call relating to the satellite providing connectivity for the first user equipment in accordance with the addressing information for the remote breakout point for the call, a step / operation (S430) of retrieving the addressing information for the local breakout point, and a step / operation (S440) of reportingthe addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0080] FIG. 6 shows a flowchart of an example method or process according to at least one example embodiment. This example method or process may be performed or carried out at / by an apparatus. The apparatus may implement (at least in part) or, stated in other words, the method or process may be a method or process of (or, stated in other words, operable or for use in / by) a UPF (e.g. I-UPF) as an example of a network function, entity or element of a communication system. The UPF (e.g. I-UPF) may be at the originating side or the terminating side of a call (which may be ongoing or may be to be established or under establishment).

[0081] As shown in FIG. 6, the method or process comprises a step / operation (S510) of obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for report of addressing information for a local breakout point for the call relating to a satellite providing connectivity for the first user equipment, and a step / operation (S510) of reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0082] FIG. 7 shows a flowchart of an example method or process according to at least one example embodiment. This example method or process may be performed or carried out at / by an apparatus. The apparatus may implement (at least in part) or, stated in other words, the method or process may be a method or process of (or, stated in other words, operable or for use in / by) a PCF as an example of a network function, entity or element of a communication system. The PCF may be at the originating side of a call (which may be ongoing or may be to be established or under establishment).

[0083] As shown in FIG. 7, the method or process comprises a step / operation (S610) of obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, a step / operation (S620) of provisioning rules, including policy and charging control rules, for the call with regard to the request for insertion of the local breakout point for the call, a step / operation (S630) of obtaining the addressing information for the local breakout point, and a step / operation (S640) of reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0084] The request in step / operation S610 may be or comprise a request for invoking policy control function services (i.e. a PCF request) including authorization of resources for the calland (together with) insertion of the local breakout point for the call. Such request may request at the PCF invoking of corresponding policy control function services.

[0085] FIG. 8 shows a flowchart of an example method or process according to at least one example embodiment. This example method or process may be performed or carried out at / by an apparatus. The apparatus may implement (at least in part) or, stated in other words, the method or process may be a method or process of (or, stated in other words, operable or for use in / by) a PCF as an example of a network function, entity or element of a communication system. The PCF may be at the originating side of a call (which may be ongoing or may be to be established or under establishment).

[0086] As shown in FIG. 8, the method or process comprises a step / operation (S710) of obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment in accordance with addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the second user equipment and report of addressing information for the local breakout point, a step / operation (S720) of provisioning rules, including policy and charging control rules, for the call with regard to the request for insertion of the local breakout point for the call, a step / operation (S730) of obtaining the addressing information for the local breakout point, and a step / operation (S740) of reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0087] The request in step / operation S710 may be or comprise a request for invoking policy control function services (i.e. a PCF request) including authorization of resources for the call in accordance with the addressing information for the remote breakout point. Such request may request at the PCF invoking of corresponding policy control function services.

[0088] FIG. 9 shows an example procedure according to at least one example embodiment. The procedure of FIG. 9 basically corresponds to an overall view / perspective on the interaction / cooperation between a P-CSCF, a PCF, a SMF and a (I-)UPF in the course of call / session establishment, i.e. upon initiation of a call. In the procedure of FIG. 9, the P-CSCF may operate in accordance with the method or process of FIG. 2, PCF may operate in accordance with the method or process of FIG. 7, the SMF may operate in accordance with the method or process of FIG. 4, and the (I-)UPF may operate in accordance with the method or process of FIG. 6. Accordingly, reference is made to the above description of FIGs. 2, 4, 6 and 7 for details of the individual operations of the network functions, entities or elements.

[0089] FIG. 10 shows an example procedure according to at least one example embodiment. The procedure of FIG. 10 basically corresponds to an overall view / perspective on the interaction / cooperation between a P-CSCF, a PCF, a SMF and a (I-)UPF in the course of call / session establishment, i.e. upon initiation of a call. In the procedure of FIG. 10, the P- CSCF may operate in accordance with the method or process of FIG. 3, PCF may operate in accordance with the method or process of FIG. 8, the SMF may operate in accordance with the method or process of FIG. 5, and the (I-)UPF may operate in accordance with the method or process of FIG. 6. Accordingly, reference is made to the above description of FIGs. 3, 5, 6 and 8 for details of the individual operations of the network functions, entities or elements.

[0090] The difference between the procedures of FIGs. 9 and 10 basically resides in that the addressing information for the remote breakout point is received at the P-CSCF at different times or stages within the procedure. While in the procedure of FIG. 9 the P-CSCF receives the addressing information for the remote breakout point after having issued the PCF request, e.g. after having provided the addressing information for the local breakout point to the remote P-CSCF (as illustrated in FIG. 9), in the procedure of FIG. 10 the P-CSCF receives the addressing information for the remote breakout point before issuing the PCF request, e.g. at the time it can detect that satellite offload is possible (such as e.g. during or after initiating call establishment) (as illustrated in FIG. 10). Accordingly, an update of the local breakout point as well as the related PCC rules at the PCF based on the addressing information for the remote breakout point is required in the procedure of FIG. 9, while in the procedure of FIG. 10, the addressing information for the remote breakout point can already been taken into consideration in the initial PCF request such that the local breakout point can be inserted and the related PCC rules can be provisioned (created or updated) at the PCF based on the addressing information for the remote breakout point, and no subsequent update is necessary.

[0091] In any one of the procedures of FIGs. 9 and 10, the PCF provisions (creates or updates) PCC rules, i.e. the user policies related with the call, with regard to (insertion of) the local breakout point (with or without consideration of addressing information for the remote breakout point, depending on availability), e.g. in connection with related resource authorization.. It is to be noted that PCC rules relate to the N7 interface between the PCF and the SMF (and can be provided via the N7 interface to the SMF), and the SMF can determine N4 rules relating to the N4 interface between the SMF and the (I-)UPF based on the PCC rules (and provide the N4 rules vis the N4 interface to the (I-)UPF).

[0092] It is to be noted that the procedures of FIGs. 9 and 10 are described in the context / course of call / session establishment, i.e. starting with / upon initiation of a call, but this is by way of example only, without limitation. The procedure of any one of FIGs. 9 and 10 can take place at any (other) time or at any (other) stage of a call or session. For example, the procedure of any one of FIGs. 9 and 10 can take place in the middle of a call, when e.g. due to mobility of at least one of the two UEs involved in the call (it is detected that) satellite traffic offload that was not possible before becomes possible. Then, a procedure corresponding to any one of the procedures of FIGs. 9 and 10, yet without the call establishment initiation step, can take place or be carried out. That is, the method or process at any one of the P-CSCF, the PCF, the SMF and / or the (I-)UPF may be triggered by or in connection with a satellite (constellation) insertion, i.e. the change of the situation that user plane traffic offloading becomes possible (e.g. by one UE newly entering into satellite coverage) while a call has already been established.

[0093] Any one of the methods or processes of FIGs. 2 to 8 and any one of the procedures of FIGS. 9 and 10 may be performed during or as part of an IMS session establishment procedure and / or a call establishment procedure but also while a call or session is already established and ongoing e.g. when due to mobility of at least one of the two UEs involved in the call or session satellite traffic offload becomes possible (as outlined above).

[0094] In the following, a potential use case of example embodiments is described. This use case is based on IMS architecture and / or procedures in the framework of a 5G / NR system, and may be realized in the example system configuration shown in FIG. 1.

[0095] FIG. 11 shows an example IMS session establishment procedure at a terminating side of an IMS call. This procedure shows provisioning of service information as well as PCC and SMF procedures for IMS session establishment at terminating P-CSCF and PCF.

[0096] As shown in FIG. 11, the procedure comprises the following steps:1. The P-CSCF receives the SDP parameters defined by the originator. It is assumed that both parties (e.g. UE(s)) involved in the call are served by the same satellite constellation (or by multiple satellite constellations supporting user plane traffic offloading, e.g. having an agreement for a joint ISL network), i.e. a UE-satellite-UE- communication (or U-plane offloading) between the two parties (e.g. UE(s)) involved in the call is feasible.2. The P-CSCF identifies the connection information needed (IP address of the up-link IP flow(s), port numbers to be used, etc.).3. The P-CSCF sends the SDP offer to the UE.4. The P-CSCF receives the negotiated SDP parameters from the UE.5. The P-CSCF identifies the connection information needed (IP address of the down-link IP flow(s), port numbers to be used, etc.) to request resource reservation.6. The P-CSCF invokes the Npcf PolicyAuthorization Create service operation to forward the derived service information to the PCF.6a. (if Rx applies instead of N5) The P-CSCF forwards the derived service information to the PCF by sending a Diameter AAR for a new Rx Diameter session. In both cases (6. and 6a) the P-CSCF uses the same request to also fetch the local user location (Access Network Information ANI) and / or UE Time Zone information from the access network (as defined in TS 23.228 e.g. step 6b of Figure R.3-1, step 5 of Figure R.4-1), and asks to insert a local N6 breakout point for the corresponding QoS resources and to report addressing information for this local N6 breakout point.If the P-CSCF assigned IMS-AGW resources before in the context of step 2, it releases the resources.7. The PCF stores the received session information, and performs session binding. For the N5 interface, the PCF creates an "Individual Application Session Context" resource to store the received application session information.8. The PCF sends a [an HTTP "201 Created"] Npcf P obey Authorization C reate response to the P-CSCF [and includes the URI of the "Individual Application Session Context" resource in the Location header field. (8a.) In case 6a applies The PCF sends a Diameter AAA to the P-CSCF],9. If the P-CSCF did not request “access network information” in step 6 (or step 6a for the Rx case), upon reception of the acknowledgement from the PCF, the SDP parameters in the SDP answer are passed to the originator.10. The PCF executes interactions according to clause 5.2.2.2.1 in TS 29.513. This step implies provisions related PCC rules corresponding to the information received in step 6 / 6a. This is executed in parallel with steps 8 (or step 8a for the Rx case) and 9.Upon reception of the PCC rules, the SMF : bl) (based on the PCF request to insert a local N6 breakout point) allocates for the PDU Session (a) (an) I-UPF(s) on the satellite currently serving the UE and configures the I-UPF(s) to act as UL CL (to break out only U-plane traffic corresponding to the SDF indicated by the PCF) and / or as L-PSA (local N6 breakoutpoint); the SMF creates a PDR / FAR referring to the network instance corresponding to the IP network of ISL (inter satellite links) and the UPF answers back with addressing information corresponding to the local N6 breakout point (termination point at the L-PSA of the N6 tunnel over the ISL network) b2) requests QoS resources and ANI (Access Network Information) from the RAN b3) reports ANI to the PCF that contains both the location information received from the RAN and addressing information corresponding to the local N6 breakout point (termination point at the L-PSA of the N6 tunnel over the ISL network).NOTE: As the remote (here originating) N6 termination information (addressing information corresponding to the remote N6 breakout point ) cannot be known at this time, the PCF shall wait for step 14 to receive the N6 termination information from originating side once originating side has set up its own U-plane resources.11. If the P-CSCF requested access network information and / or EPS fallback indication in step 6, the PCF invokes the Npcf PolicyAuthorization Notify service operation to forward EPS fallback indication, if received in step 10, and / or the ANI received in step 10 [by sending an HTTP POST request to the Notification URI received in step 6], I la. Rx equivalent of the N5 procedure described in step 11.12. If step 11 occurs, the P-CSCF acknowledges the receipt of the notification request with an [HTTP "204 No Content"] Npcf_PolicyAuthorization_Notify response.12a. If step I la occurs, the P-CSCF acknowledges the receipt of Diameter RAR.13. If step 11 occurs (or step 1 la for the Rx case), the P-CSCF forwards the SDP answer and includes the location information received from the RAN and addressing information corresponding to the local N6 breakout point (termination point at the L- PSA of the N6 tunnel over the ISL network) (called local outer IP address in the figure) in the next SIP message the P-CSCF sends towards the IMS core network.As a difference with R18 behaviour the IMS Core of the local UE ensures that information corresponding to the addressing information corresponding to the local N6 breakout point (termination point at the L-PSA of the N6 tunnel over the ISL network) is transferred via SIP signaling towards the P-CSCF handling the other party (here originator of the call).14. The terminating P-CSCF receives addressing information (called remote outer IP address in the figure) corresponding to the remote N6 breakout point transferred via SIP signaling (and ensures this information is not sent to the UE).15. The P-CSCF provides (via PCF) the SMF with addressing information corresponding to the remote N6 breakout point. This information is sent to the SMF via traffic steering information in a PCC rule (refer to clause 6.3.1 in TS 23.503 for “Application Function influence on traffic routing Enforcement Control”)16. The SMF Sends a corresponding N4 PDR / FAR to the UPF in such a way that media from the local UE to the remote UE is sent by the local PSA (UL-CL I-UPF) (inserted in step 10 bl) in a tunnel whose destination address corresponds to the addressing information of the remote N6 breakout point: the SMF updates the corresponding FAR / Forwarding Parameters / Outer Header Creation accordingly.If the addressing information of the remote N6 breakout point corresponds to the local PSA (i.e. if both the UEs are served by same satellite) then local traffic switching at the L-PSA needs to take place.NOTE: The local switching can be determined by UPF based on implementation dependant mechanism or by keeping dedicated PtP tunnel for loopback routing.

[0097] FIG. 12 shows an example IMS session establishment procedure at an originating side of an IMS call. This procedure shows provisioning of service information as well as PCC and SMF procedures for IMS session establishment at terminating P-CSCF and PCF.

[0098] As shown in FIG. 12, the procedure comprises the following steps:1. The P-CSCF receives the SDP parameters defined by the originator within an SDP offer in SIP signaling. It is assumed that both parties (e.g. UE(s)) involved in the call are served by the same satellite constellation (or by multiple satellite constellations supporting user plane traffic offloading, e.g. having an agreement for a joint ISL network), i.e. a UE-satellite-UE-communication (or U-plane offloading) between the two parties (e.g. UE(s)) involved in the call is feasible.2. The P-CSCF identifies the connection information needed (IP address of the down link IP flow(s), port numbers to be used, etc.).3. The P-CSCF forwards the SDP offer in SIP signaling.4. The P-CSCF gets the negotiated SDP parameters from the terminating side through SIP signaling interaction together with addressing information corresponding to the remote N6 breakout point (termination point at the L-PSA of the N6 tunnel over the ISL network) (called remote outer IP address in the figure) and / or LUPF’s local termination information. (This corresponds to local outer IP address from terminating side in step 13 in FIG. 11)5. The P-CSCF identifies the connection information needed (IP address of the up-link media IP flow(s), port numbers to be used, etc.).6. The P-CSCF invokes the Npcf PolicyAuthorization Create service operation to forward the derived session information to the PCF by sending an HTTP POST request to the "Application Sessions" resource.6a. The P-CSCF provides session information to the PCF by sending a Diameter AAR for a new Rx Diameter session.7. The PCF stores application session information and performs session binding. For N5 interface, the PCF creates an "Individual Application Session Context" resource to store the received application session information.8. The PCF replies to the P-CSCF with a HTTP "201 Created" response and includes the URI of the "Individual Application Session Context" resource in the Location header field.8a. The PCF sends a Diameter AAA to the P-CSCF.9. Upon reception of the acknowledgement from the PCF, the SDP parameters are passed to the UE in SIP signaling.10. The PCF executes interactions according to figure 5.2.2.2-1 in TS 29.513. This step implies provisioning of PCC rules and is executed in parallel with steps 8 and 9 (steps 8a and 9a for Rx case).Upon reception of the PCC rules, the SMF : bl) (based on the PCF request to insert a local N6 breakout point) allocates for the PDU Session (a) (an) I-UPF(s) on the satellite currently serving the UE and configures the UPF(s) to act as UL CL (to break out only U-plane traffic corresponding to the SDF indicated by the PCF) and / or as L-PSA (local N6 breakout point); the SMF creates a PDR / FAR referring to the network instance corresponding to the IP network of ISL (inter satellite links) and the UPF answers back with addressing information corresponding to the local N6 breakout point (termination point at the L-PSA of the N6 tunnel over the ISL network),, provides addressing information of the remote N6 breakout point (called remote outer IP address in the figure) and the I-UPF answers back with addressing information corresponding to the local N6 breakout point (termination point at the L-PSA of the N6 tunnel over the ISL network of the terminating side)If the addressing information of the remote N6 breakout point corresponds to the local PSA (i.e. if both the UEs are served by same satellite) then local traffic switching at the L-PSA needs to take place.NOTE: The local switching can be determined by the PSAUPF based on implementation dependent mechanism or by keeping dedicated PtP tunnel for loopback routing. b2) requests QoS resources and ANI (Access Network Information) from the RAN b3) reports ANI to the PCF that contains both the information received from the RAN and addressing information corresponding to the local N6 breakout point (termination point at the L-PSA of the N6 tunnel over the ISL network).11. If the P-CSCF requested ANI and / or EPS fallback indication in step 6, the PCF invokes the Npcf PolicyAuthorization Notify service operation to forward the EPS fallback indication, if received in step 10, and / or the ANI received in step 10 in an HTTP POST request sent to the Notification URI received in step 6.I la. If the P-CSCF requested ANI and / or EPS fallback indication in step 6a, the PCF forwards the EPS fallback indication, if received in step 10, and the ANI received in step 10 in a Diameter RAR.12. If step 11 occurs, the P-CSCF acknowledges the receipt of the notification request with an [HTTP "204 No Content"] Npcf_PolicyAuthorization_Notify response to the PCF.12a. If step I la occurs, the P-CSCF acknowledges the receipt of Diameter RAR.13. If step 11 occurs (step 1 la for Rx case), the P-CSCF forwards the network provided location information in a subsequent SIP message to IMS core network together with addressing information corresponding to the local N6 breakout point (termination point at the L-PSA of the N6 tunnel over the ISL network) (called local outer IP address in the figure). (This corresponds to remote outer IP address from originating side in step 14 in FIG. 11)

[0099] As noted above, in the procedures of FIGs. 11 and 12, it is assumed that a UE-satellite- UE-communi cation (or U-plane offloading) between the two parties (e.g. UE(s)) involved in the call is feasible e.g. both parties (e.g. UE(s)) involved in the call are served by the same satellite constellation.

[0100] FIG. 13 (including FIGs. 13 A and 13B) shows an example end-to-end IMS session establishment procedure. The procedure of FIG. 13 corresponds to a combination of the procedures of FIGs. 11 and 12, and is provided for facilitating an overview of an end-to-endcall (establishment) flow. Accordingly, reference is made to the description of FIGs. 11 and 12 for details.

[0101] As described above, one or more example embodiments can encompass / realize one or more of the following aspects.

[0102] The IMS U-plane entity routing is moved on-board the satellite(s) to avoid delay caused by the longer distance between the regenerative RAN on-board satellite and U-plane functions at the ground.

[0103] The IMS contact address is kept anchored to ground UPF. This helps in avoiding frequent re-REGISTER when there is frequent satellite change.

[0104] For U-plane offloading on-board satellites, I-UPF is inserted onboard satellites and appropriate filter rules are provided / applied for U-plane traffic routing.

[0105] According to one or more example embodiments, when parties involved in a (IMS) call (which may still be under establishment) are served by satellites that can exchange user plane traffic over ISL(s), this user plane traffic is tunneled between local I-UPFs located on these satellites.

[0106] According to one or more example embodiments, when the P-CSCF invokes PCF services to request Authorization of QoS resources and to fetch the user location (ANI) from the access network, the P-CSCF may ask to insert a local N6 breakout point (I-UPF) for the corresponding QoS resources and to report addressing information for this local N6 breakout point.

[0107] According to one or more example embodiments, addressing information for the local N6 breakout point of a party involved in a session is exchanged between P-CSCF(s) (of parties involved in a session) over SIP.

[0108] According to one or more example embodiments, the SMF supports the necessary PCC rules and procedures to support the actions described herein(above).

[0109] According to one or more example embodiments, it may be assumed that the ISL(s) (Inter Satellite Link) can be within the same satellite or same satellite constellation or across different constellations depending on the satellite operator’s deployments. An ISL IP network using ISL links is used for UE-satellite-UE user plane communication where UPF (I-UPF) onboard a satellite relating to a UE can route user plane packets to UPF (I-UPF) onboard a satellite relating to the other UE can. PtP (refer to 3GPP TS 29.561) tunnelling can be applicable for I-UPF to I-UPF packet forwarding where the media flows with the inner source / destination IP address of both UE(s) may be sent in an PtP tunnel, where the outersource / destination IP address(es) corresponding to (the IP address(es) of) the I-UPF(s) serving each of the UE(s). It may be assumed that each I-UPF in every satellite will have a dedicated PtP tunnel over the ISL link to avoid any routing mechanism at I-UPF. It is to be noted that this means that no IMS level media entities (IMS-AGW, TrGW) on the ground shall / will be used in the session path.

[0110] According to one or more example embodiments, a sequence of operations at various network functions, entities or elements may include one or more of the operations which are described below as examples for the P-CSCF / PCF / SMF at the originating side of an IMS call where QoS resources are reserved in case the P-CSCF detected that direct routing within the satellite constellation is possible a) If applicable, the P-CSCF removes the IMS-AGW on the ground it may have assigned to the session path, as it is not needed for user plane traffic within a satellite constellation. b) When the P-CSCF invokes PCF services to request Authorization of QoS resources and to fetch the user location (ANI) from the access network (as defined in 3 GPP TS 23.228 V18.4.0 e.g. step 6b of Figure R.3-1, step 5 of Figure R.4-1), the P-CSCF may ask to insert a local N6 breakout point for the corresponding QoS resources and to report addressing information for this local N6 breakout point.NOTE: This is done using Rx / N5 services and not Nnef Traffic Influence API. Using Nnef Traffic Influence API would be possible but would require more API invocation between P-CSCF (acting as an AF) and the PCF, which in turn would have induced more N7 and N4 signaling. c) The PCF, via PCC rules, transfers the request to the SMF. Thereupon, the SMF : cl) (based on the PCF request to ask to insert a local N6 breakout point) allocates for the Session (a) I-UPF(s) on the satellite currently serving the UE and configures the UPF(s) to act as UL CL (to break out only traffic corresponding to the SDF indicated by the PCF) and / or as L-PSA (local N6 breakout point); it retrieves from the L-PSA UPF the local (outer IP) addressing information corresponding to the local N6 breakout point c2) requests QoS resources and location information from the RAN c3) reports to the PCF, ANI that contains both the location information received from the RAN and (outer IP) address information corresponding to the local N6 breakout point (and retrieved from the L-PSA).d) The PCF reports the information provided by the SMF to the P-CSCF, which ensures that the (outer IP) addressing information corresponding to the local N6 breakout point is transferred via SIP header (e.g. SIP PANI) to the P-CSCF handling the other party. e) When the P-CSCF receives (outer IP) addressing information corresponding to the N6 breakout point of the other party, it transfers the information to the PCF, which updates the corresponding PCC rule to the SMF. The SMF updates the PSA UPF with the received (outer IP) addressing information to be used for UL media traffic to be sent on the ISL IP network.If Step b) and Step e) take place at the same time, the P-CSCF, having received remote (outer IP) addressing information from the remote party before it has requested Authorization of QoS resources, can at the same time request local traffic switching and provide remote (outer IP) addressing information.

[0111] According to one or more example embodiments, e.g. in the configuration of FIG. 1, the IBCF in the IMS (at either side) may allow SIP to carry information regarding (outer IP) addressing information. The IBCF does not need to add a TrGW to the session path.

[0112] According to one or more example embodiments, e.g. in the configuration of FIG. 1, the P-CSCF in the IMS (at either side), when invoking PCF for Authorization of QoS resources and to fetch the user location (ANI), may request to insert a local N6 breakout point for the corresponding QoS resources and to report addressing information for this local N6 breakout point. The P-CSCF may send addressing information for the local N6 breakout point (received from PCF) to the other end of the call (e.g. to the remote P-CSCF) via SIP signaling.

[0113] According to one or more example embodiments, e.g. in the configuration of FIG. 1, the PCF (at either side) may support a request to insert a local N6 breakout point for the corresponding QoS resources and to report (outer IP) addressing information for this local N6 breakout point and transform this request into relevant PCC rules. Further, the PCF may notify the consumer (e.g. the P-CSCF) when receiving from the SMF (outer IP) addressing information for the local N6 breakout point.

[0114] According to one or more example embodiments, e.g. in the configuration of FIG. 1, the SMF (at either side) may, based on the PCF request (PCC rule) to insert a local N6 breakout point, one or more of:o allocating for the Session (a) I-UPF(s) on the satellite currently serving the UE; o configuring the UPF(s) to act as UL CL (to break out only traffic corresponding to the SDF indicated by the PCF) and / or as L-PSA (local N6 breakout point); o retrieving from the L-PSA UPF the local (outer IP) addressing information corresponding to the local N6 breakout point; o providing the remote (outer IP) addressing information to the L-PSA UPF.

[0115] Further, the SMF may report to the PCF ANI that contains both the location information received from the RAN and (outer IP) addressing information corresponding to the local N6 breakout point (and retrieved from the L-PSA).

[0116] According to one or more example embodiments, e.g. in the configuration of FIG. 1, the UPF (I-UPF) (at either side) may provide to SMF the local (outer IP) addressing information corresponding to the network instance in a PDR. Further, the UPF may detect, based on the remote (outer IP) addressing information, that some traffic is to be locally switched at the UPF (based on FAR / Forwarding Rules / Outer Header creation containing the L-PSA own outer IP address)

[0117] The above-described functionality as well as its related operations, procedures, methods and processes may be implemented by respective functional elements, entities, modules, units, processors, or the like, as described below. These functional elements, entities, modules, units, processors, or the like, e.g., the implementation of one or more example embodiments, may be realized in a cloud environment, by SDN, by NFV / NFVI, or the like.

[0118] While various example embodiments are described with reference to operations, procedures, methods and processes, these example embodiments also cover respective apparatuses, entities, modules, units, network nodes and / or systems, including software and / or hardware thereof.

[0119] Respective example embodiments are described below, while for the sake of brevity reference is made to the detailed description of respective corresponding configurations / setups, schemes, structures, processes, sequences, methods as well as functionalities, principles and operations according to FIGS. 1 to 13. These configurations / setups, schemes, structures, processes, sequences, methods as well as functionalities, principles and operations equally apply for respective apparatuses, entities, modules, units, network nodes and / or systems, including software and / or hardware thereof.

[0120] In Figures 14 and 15, the blocks are basically configured to perform respective methods, procedures and / or functions as described above. The entirety of blocks are basically configured to perform the methods, procedures and / or functions as described above, respectively. With respect to Figures 14 and 15, it is to be noted that the individual blocks are meant to illustrate respective functional blocks implementing a respective function, process or procedure, respectively. Such functional blocks are implementation-independent, i.e. may be implemented by means of any kind of hardware or software or combination thereof, respectively.

[0121] Further, in Figures 14 and 15, only those functional blocks are illustrated, which relate to any one of the above-described methods, procedures and / or functions. A skilled person will acknowledge the presence of any other conventional functional blocks required for an operation of respective structural arrangements, such as e.g. a power supply, a central processing unit, respective memories or the like. Among others, one or more memories are provided for storing programs or program instructions for controlling or enabling the individual functional entities or any combination thereof to operate as described herein in relation to example embodiments.

[0122] FIG. 14 shows a schematic diagram illustrating a structure of apparatuses according to at least one example embodiment. Herein, an apparatus can represent a physical entity or component, e.g., a structural device implementing a specific network element, entity or function or the functionality thereof as such, or a functional or logical entity or component. For example, the illustrated apparatus may be realized in or by a server or the like in a cloud environment, e.g., by a cloud-based implementation.

[0123] As indicated in FIG. 14, according to at least one example embodiment, an apparatus 1400 may comprise or realize at least one processor 1410 and at least one memory 1420 and at least one interface 1430, which may be operationally connected or coupled, for example by a bus 1440 or the like, respectively. The processor 1410 and the memory 1420 may be included in or be part of processing circuitry.

[0124] The processor 1410 and / or the interface 1430 of the apparatus 1400 may also include a modem or the like to facilitate communication over a (e.g., hardwire or wireless) link, respectively. The interface 1430 of the apparatus 1400 may include at least one transmitter and / or at least receiver and / or at least one transceiver connected or coupled to one or more antennas, antenna units, such as antenna arrays or communication facilities or means for (e.g., hardwire or wireless) communications with the linked, coupled or connected device(s), respectively. The interface 1430 of the apparatus 1400 is generally configured to communicatewith at least one other apparatus, device, node or entity (in particular, the interface thereof), and may be (considered or referred to as) a network interface.

[0125] The memory 1420 of the apparatus 1400 may represent a (non-transitory / tangible) storage medium (e.g., RAM, ROM, EPROM, EEPROM, etc.) and store respective software, programs, program products, macros or applets, etc. or parts of them, which may be assumed to comprise program instructions or computer program code that, when executed by the respective processor, enables the respective electronic device or apparatus to operate in accordance with example embodiments described herein. Further, the memory 1420 of the apparatus 1400 may (comprise a database to) store any data, information, or the like, which is used in the operation of the apparatus.

[0126] According to various example embodiments, respective apparatuses (and / or parts thereof) may represent means for performing respective operations and / or exhibiting respective functionalities, and / or the respective devices (and / or parts thereof) may have functions for performing respective operations and / or exhibiting respective functionalities.

[0127] In view of the above, the illustrated apparatus 1400 can be used in practicing one or more of the example embodiments, as described herein.

[0128] According to at least one example embodiment, the illustrated apparatus 1400 may represent or realize / embody a (e.g., part of a) P-CSCF. Hence, the apparatus 1400 may be configured to perform a procedure and / or exhibit a functionality and / or implement a mechanism, as described (e.g., for a P-CSCF) in any one of FIGS. 1 to 3 and 9 to 13.

[0129] Accordingly, the apparatus 1400 may be caused or the apparatus 1400 or its at least one processor 1410 (e.g., together with instructions stored in its at least one memory 1420) may be configured to request, for a call between a first user equipment and a second user equipment via a satellite communication, insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, obtain the addressing information for the local breakout point, and provide the addressing information for the local breakout point towards a network entity of a network serving the second user equipment.

[0130] Further, the apparatus 1400 may be caused or the apparatus 1400 or its at least one processor 1410 (e.g., together with instructions stored in its at least one memory 1420) may be configured to perform any one of the methods, functionalities or operations, as described with respect to a P-CSCF.

[0131] According to at least one example embodiment, the illustrated apparatus 1400 may represent or realize / embody a (e.g., part of a) SMF. Hence, the apparatus 1400 may be configured to perform a procedure and / or exhibit a functionality and / or implement a mechanism, as described (e.g., for a SMF) in any one of FIGS. 1, 4 to 5 and 9 to 13.

[0132] Accordingly, the apparatus 1400 may be caused or the apparatus 1400 or its at least one processor 1410 (e.g., together with instructions stored in its at least one memory 1420) may be configured to obtain, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, insert the local breakout point for the call relating to the satellite providing connectivity for the first user equipment, retrieve the addressing information for the local breakout point, and report the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0133] Further, the apparatus 1400 may be caused or the apparatus 1400 or its at least one processor 1410 (e.g., together with instructions stored in its at least one memory 1420) may be configured to perform any one of the methods, functionalities or operations, as described with respect to a SMF.

[0134] According to at least one example embodiment, the illustrated apparatus 1400 may represent or realize / embody a (e.g., part of a) (I-)UPF. Hence, the apparatus 1400 may be configured to perform a procedure and / or exhibit a functionality and / or implement a mechanism, as described (e.g., for a (I-)UPF) in any one of FIGS. 1, 6, 9 to 13.

[0135] Accordingly, the apparatus 1400 may be caused or the apparatus 1400 or its at least one processor 1410 (e.g., together with instructions stored in its at least one memory 1420) may be configured to obtain, for a call between a first user equipment and a second user equipment via a satellite communication, a request for report of addressing information for a local breakout point for the call relating to a satellite providing connectivity for the first user equipment, and report the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0136] Further, the apparatus 1400 may be caused or the apparatus 1400 or its at least one processor 1410 (e.g., together with instructions stored in its at least one memory 1420) may be configured to perform any one of the methods, functionalities or operations, as described with respect to a (I-)UPF.

[0137] According to at least one example embodiment, the illustrated apparatus 1400 may represent or realize / embody a (e.g., part of a) PCF. Hence, the apparatus 1400 may be configured to perform a procedure and / or exhibit a functionality and / or implement a mechanism, as described (e.g., for a PCF) in any one of FIGS. 1 and 7 to 13.

[0138] Accordingly, the apparatus 1400 may be caused or the apparatus 1400 or its at least one processor 1410 (e.g., together with instructions stored in its at least one memory 1420) may be configured to obtain, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, provision rules, including policy and charging control rules, for the call with regard to the request for insertion of the local breakout point for the call, obtain the addressing information for the local breakout point, and report the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0139] Further, the apparatus 1400 may be caused or the apparatus 1400 or its at least one processor 1410 (e.g., together with instructions stored in its at least one memory 1420) may be configured to perform any one of the methods, functionalities or operations, as described with respect to a PCF.

[0140] As mentioned above, an apparatus according to at least one example embodiment may be structured by comprising respective one or more units or means or circuitries for performing corresponding operations, procedures and / or functions. For example, such one or more units or means or circuitries may be implemented / realized on the basis of an apparatus structure, as illustrated in FIG. 14, e.g., by one or more processors 1410, one or more memories 1420, one or more interfaces 1430, or any combination thereof.

[0141] FIG. 15 shows a schematic diagram illustrating a structure of apparatuses according to at least one example embodiment.

[0142] As shown in FIG. 15, an apparatus 1510 according to at least one example embodiment may represent or realize / embody a (e.g., part of a) P-CSCF. Hence, the apparatus 1510 may be configured to perform a procedure and / or exhibit a functionality and / or implement a mechanism, as described (e.g., for a P-CSCF) in any one of FIGS. 1 to 3 and 9 to 13.

[0143] The apparatus 1510 may comprise (at least) one or more unit / means / circuitry, denoted by requesting section 1511, which represent any implementation for (or configured to) requesting (request) requesting, for a call between a first user equipment and a second userequipment via a satellite communication, insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, unit / means / circuitry, denoted by obtaining section 1512, which represent any implementation for (or configured to) obtaining (obtain) the addressing information for the local breakout point, and unit / means / circuitry, denoted by providing section 1513, which represent any implementation for (or configured to) providing (provide) the addressing information for the local breakout point towards a network entity of a network serving the second user equipment.

[0144] Further, the apparatus 1510 may comprise one or more unit / means / circuitry, denoted by invoking section 1514, which represent any implementation for (or configured to) invoking (invoke) policy control function services including authorization of resources for the call together with insertion of the local breakout point for the call. Further, the apparatus 1510 may comprise one or more unit / means / circuitry, denoted by sending section 1515, which represent any implementation for (or configured to) sending (send), towards a proxy call session control function of the network serving the second user equipment, a message including the addressing information for the local breakout point. Further, the apparatus 1510 may comprise one or more unit / means / circuitry, denoted by receiving section 1516, which represent any implementation for (or configured to) receiving (receive), from a proxy call session control function of the network serving the second user equipment, a message including the addressing information for the remote breakout point.

[0145] Further, the requesting means 1511 (or dedicated, separate or different obtaining means) may represent any implementation for (or configured to) performing or carrying out (perform or carry out) any requesting(-related) operation or functionalitiy of a P-CSCF, as described herein. Further, the obtaining means 1512 (or dedicated, separate or different obtaining means) may represent any implementation for (or configured to) performing or carrying out (perform or carry out) any obtaining(-related) operation or functionalitiy of a P- CSCF, as described herein. Further, the providing means 1513 (or dedicated, separate or different obtaining means) may represent any implementation for (or configured to) performing or carrying out (perform or carry out) any providing(-related) operation or functionalitiy of a P-CSCF, as described herein.

[0146] As shown in FIG. 15, an apparatus 1520 according to at least one example embodiment may represent or realize / embody a (e.g., part of a) SMF. Hence, the apparatus 1520 may beconfigured to perform a procedure and / or exhibit a functionality and / or implement a mechanism, as described (e.g., for a SMF) in any one of FIGS. 1, 4 to 5 and 9 to 13.

[0147] The apparatus 1520 may comprise (at least) one or more unit / means / circuitry, denoted by obtaining section 1521, which represent any implementation for (or configured to) obtaining (obtain) , for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, one or more unit / means / circuitry, denoted by inserting section 1522, which represent any implementation for (or configured to) inserting (insert) the local breakout point for the call relating to the satellite providing connectivity for the first user equipment, one or more unit / means / circuitry, denoted by retrieving section 1523, which represent any implementation for (or configured to) retrieving (retriev) retrieving the addressing information for the local breakout point, and one or more unit / means / circuitry, denoted by reporting section 1524, which represent any implementation for (or configured to) reporting (report) reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0148] Further, the apparatus 1520 may comprise one or more unit / means / circuitry, denoted by allocating section 1524, which represent any implementation for (or configured to) allocating (allocate) one or more intermediate user plane functions at the satellite providing connectivity for the first user equipment, and one or more unit / means / circuitry, denoted by configuring section 1525, which represent any implementation for (or configured to) configuring (configure) the one or more intermediate user plane functions to act as a local packet data unit session anchor. Further, the apparatus 1520 may comprise one or more unit / means / circuitry, denoted by updating section 1526, which represent any implementation for (or configured to) updating (update) a local packet data unit session anchor, corresponding to the local breakout point relating to the satellite providing connectivity for the first user equipment, in accordance with the addressing information for the remote breakout point for the call.

[0149] Further, the obtaining means 1521 (or dedicated, separate or different obtaining means) may represent any implementation for (or configured to) performing or carrying out (perform or carry out) any obtaining(-related) operation or functionalitiy of a SMF, as described herein. Further, the inserting means 1522 (or dedicated, separate or different obtaining means) may represent any implementation for (or configured to) performing or carrying out (perform orcarry out) any inserting(-related) operation or functionalitiy of a SMF, as described herein. Further, the retrieving means 1523 (or dedicated, separate or different obtaining means) may represent any implementation for (or configured to) performing or carrying out (perform or carry out) any retrieving(-related) operation or functionalitiy of a SMF, as described herein.

[0150] Further, the reporting means 1524 (or dedicated, separate or different obtaining means) may represent any implementation for (or configured to) performing or carrying out (perform or carry out) any reporting(-related) operation or functionalitiy of a SMF, as described herein.

[0151] As shown in FIG. 15, an apparatus 1530 according to at least one example embodiment may represent or realize / embody a (e.g., part of a) (I-)UPF. Hence, the apparatus 1520 may be configured to perform a procedure and / or exhibit a functionality and / or implement a mechanism, as described (e.g., for a (I-)UPF) in any one of FIGS. 1, 6, 9 to 13.

[0152] The apparatus 1530 may comprise (at least) one or more unit / means / circuitry, denoted by obtaining section 1531, which represent any implementation for (or configured to) obtaining (obtain), for a call between a first user equipment and a second user equipment via a satellite communication, a request for report of addressing information for a local breakout point for the call relating to a satellite providing connectivity for the first user equipment, and one or more unit / means / circuitry, denoted by reporting section 1532, which represent any implementation for (or configured to) reporting (report) the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0153] Further, the obtaining means 1531 (or dedicated, separate or different obtaining means) may represent any implementation for (or configured to) performing or carrying out (perform or carry out) any obtaining(-related) operation or functionalitiy of a (I-)UPF, as described herein. Further, the reporting means 1532 (or dedicated, separate or different obtaining means) may represent any implementation for (or configured to) performing or carrying out (perform or carry out) any reporting(-related) operation or functionalitiy of a (I-)UPF, as described herein.

[0154] As shown in FIG. 15, an apparatus 1540 according to at least one example embodiment may represent or realize / embody a (e.g., part of a) PCF. Hence, the apparatus 1520 may be configured to perform a procedure and / or exhibit a functionality and / or implement a mechanism, as described (e.g., for a PCF) in any one of FIGS. 1 and 7 to 13.

[0155] The apparatus 1540 may comprise (at least) one or more unit / means / circuitry, denoted by obtaining section 1541, which represent any implementation for (or configured to) obtaining (obtain), for a call between a first user equipment and a second user equipment via a satellitecommunication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, one or more unit / means / circuitry, denoted by provisioning section 1542, which represent any implementation for (or configured to) provisioning (provision) rules, including policy and charging control rules, for the call with regard to the request for insertion of the local breakout point for the call, one or more unit / means / circuitry, denoted by obtaining section 1543, which represent any implementation for (or configured to) obtaining (obtain) the addressing information for the local breakout point, and one or more unit / means / circuitry, denoted by reporting section 1544, which represent any implementation for (or configured to) reporting (report) reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

[0156] Further, the apparatus 1540 may comprise one or more unit / means / circuitry, denoted by initiating section 1545, which represent any implementation for (or configured to) initiating (initiate) policy control function services including authorization of resources for the call together with insertion of the local breakout point for the call.

[0157] Further, the obtaining means 1541 or 1543 (or dedicated, separate or different obtaining means) may represent any implementation for (or configured to) performing or carrying out (perform or carry out) any obtaining(-related) operation or functionalitiy of a PCF, as described herein. Further, the provisioning means 1542 (or dedicated, separate or different obtaining means) may represent any implementation for (or configured to) performing or carrying out (perform or carry out) any provisioning(-related) operation or functionalitiy of a PCF, as described herein. Further, the reporting means 1544 (or dedicated, separate or different obtaining means) may represent any implementation for (or configured to) performing or carrying out (perform or carry out) any reporting(-related) operation or functionalitiy of a PCF, as described herein.

[0158] For further details regarding the operability / functionality of the apparatuses (or units / means thereof) according to example embodiments, reference is made to the above description in connection with any one of FIGS. 1 to 13, respectively.

[0159] According to example embodiments, any one of the (at least one) processor, the (at least one) memory and the (at least one) interface, as well as any one of the illustrated units / means, may be implemented as individual modules, chips, chipsets, circuitries or the like, or one or more of them can be implemented as a common module, chip, chipset, circuitry or the like, respectively.

[0160] As used herein, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions), and (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.

[0161] 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, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0162] According to some example embodiments, a system may comprise any conceivable combination of any depicted or described apparatuses and other network elements or functional entities, which are configured to cooperate as described above.

[0163] In general, it is to be noted that respective functional blocks or elements according to various embodiments described herein can be implemented by any known means, either in hardware and / or software, respectively, if it is only adapted to perform the described functions of the respective parts. The mentioned method steps can be realized in individual functional blocks or by individual devices, or one or more of the method steps can be realized in a single functional block or by a single device.

[0164] Generally, a basic system architecture of a (tele)communication network including a mobile communication system where some examples of example embodiments are applicable may include an architecture of one or more communication networks including wireless access network sub- / system(s) and possibly core network(s). Such an architecture may include one or more communication network control elements or functions, such as e.g. access network elements, radio access network elements, access service network gateways or base transceiver stations, like a base station, an access point, a NodeB (NB), an eNB or a gNB, a distributed ora centralized unit, which controls a respective coverage area or cell(s) and with which one or more communication stations such as communication elements or functions, like user devices or terminal devices, like a UE, or another device having a similar function, such as a modem chipset, a chip, a module, and so forth, which can also be part of a station, an element, a function or an application capable of conducting a communication, such as a UE, an element or function usable in a machine-to-machine communication architecture, or attached as a separate element to such an element, function or application capable of conducting a communication, or the like, are capable to communicate via one or more channels via one or more communication beams for transmitting several types of data in a plurality of access domains. Furthermore, core network elements or network functions, such as gateway network elements / functions, mobility management entities, a mobile switching center, servers, databases and the like may be included.

[0165] The general functions and interconnections of the described elements and functions, which also depend on the actual network type, are known to those skilled in the art and described in corresponding specifications, so that a detailed description thereof is omitted herein. It should be appreciated that several additional network elements and signaling links may be employed for a communication to or from an element, function or application, like a communication endpoint, a communication network control element, such as a server, a gateway, a radio network controller, and other elements of the same or other communication networks besides those described in detail herein below.

[0166] A communication network architecture as being considered in examples of example embodiments may also be able to communicate with other networks, such as a public switched telephone network or the Internet, including the Internet-of-Things. The communication network may also be able to support the usage of cloud services for virtual network elements or functions thereof, wherein it is to be noted that the virtual network part of the (tele)communication network can also be provided by non-cloud resources, e.g. an internal network or the like. It should be appreciated that network elements of an access system, of a core network, and so forth, and / or respective functionalities may be implemented by using any node, host, server, access node or entity, and so forth being suitable for such a usage. Generally, a network function can be implemented either as a network element on a dedicated hardware, as a software instance running on a dedicated hardware, or as a virtualized function instantiated on an appropriate platform, e.g. a cloud infrastructure.

[0167] Any method step is suitable to be implemented as software or by hardware without changing the idea or scope of the various example embodiments. Such software may be software code independent and can be specified using any known or future developed programming language, such as e.g. Java, C++, C, and Assembler, as long as the functionality defined by the method steps is preserved. Such hardware may be hardware type independent and can be implemented using any known or future developed hardware technology or any hybrids of these, such as MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), TTL (Transistor-Transistor Logic), and so forth, using for example ASIC (Application Specific IC (Integrated Circuit)) components, FPGA (Field-programmable Gate Arrays) components, CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components. A device / apparatus may be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device / apparatus or module, instead of being hardware implemented, be implemented as software in a (software) module, such as a computer program or a computer program product comprising executable software code portions for execution / being run on a processor. A device may be regarded as a device / apparatus or as an assembly of more than one device / apparatus, whether functionally in cooperation with each other or functionally independently of each other but in a same device housing, for example.

[0168] Apparatuses and / or units / means or parts thereof can be implemented as individual devices, but this does not exclude that they may be implemented in a distributed fashion throughout the system, as long as the functionality of the device is preserved. Such and similar principles are to be considered as known to a skilled person.

[0169] Software in the sense of the description comprises software code as such comprising code means or portions or a computer program or a computer program product for performing the respective functions, as well as software (or a computer program or a computer program product) embodied on a tangible medium, such as a computer-readable (storage) medium having stored thereon a respective data structure or code means / portions or embodied in a signal or in a chip, potentially during processing thereof.

[0170] Various example embodiments also cover any conceivable combination of method steps and operations described above, and any conceivable combination of nodes, apparatuses, modules or elements described above, as long as the above-described concepts of methodology and structural arrangement are applicable.

[0171] In view of the above, there are provided measures for (e.g. enabling / facilitating / realizing enhancements and / or improvements for) management / control of UE-satellite-UE communication, i.e. a satellite communication between a first user equipment and a second user equipment. Such measures may, for example, comprise that a network function, element or entity, such as e.g. a P-CSCF, requests, for a call between a first user equipment and a second user equipment via a satellite communication, insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, obtains the addressing information for the local breakout point, and provides the addressing information for the local breakout point towards a network entity of a network serving the second user equipment.

[0172] Even though various example embodiments are described above with reference to the accompanying drawings, it is to be understood that the various example embodiments are not restricted thereto. Rather, it is apparent to those skilled in the art that the various example embodiments can be modified in many ways without departing from the intended scope.

Claims

Claims1. A method, comprising: requesting, for a call between a first user equipment and a second user equipment via a satellite communication, insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, obtaining the addressing information for the local breakout point, and providing the addressing information for the local breakout point towards a network entity of a network serving the second user equipment.

2. The method according to claim 1, comprising: invoking policy control function services including authorization of resources for the call and insertion of the local breakout point for the call.

3. The method according to claim 1 or 2, wherein the insertion of a local breakout point and the report of addressing information for the local breakout point are requested at a policy control function of a network serving the first user equipment, and / or the addressing information for the local breakout point is obtained from a policy control function of a network serving the first user equipment.

4. The method according to any one of claims 1 to 3, comprising: sending, towards a proxy call session control function of the network serving the second user equipment, a message including the addressing information for the local breakout point.

5. The method according to claim 4, wherein the addressing information for the local breakout point is contained in a session initiation protocol message or a session initiation protocol header or a session description protocol message, and / or the addressing information for the local breakout point is contained in a P-Access- Network-Info header.

6. The method according to any one of claims 1 to 5, comprising: obtaining addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the second user equipment, and providing the addressing information for the remote breakout point towards at least one network entity of a network serving the first user equipment.

7. The method according to claim 6, comprising: receiving, from a proxy call session control function of the network serving the second user equipment, a message including the addressing information for the remote breakout point.

8. The method according to claim 7, wherein the addressing information for the remote breakout point is contained in a session initiation protocol message or a session initiation protocol header or a session description protocol message, and / or the addressing information for the remote breakout point is contained in a P-Access- Network-Info header.

9. The method according to any one of claims 6 to 8, comprising: invoking policy control function services including authorization of resources for the call in accordance with the addressing information for the remote breakout point.

10. The method according to any one of claims 1 to 5, comprising: obtaining addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the first user equipment, wherein the requesting comprises requesting insertion of the local breakout point for the call in accordance with the addressing information for the remote breakout point.

11. The method according to claim 10, comprising: invoking policy control function services including authorization of resources for the call and insertion of the local breakout point for the call in accordance with the addressing information for the remote breakout point.

12. The method according to any one of claims 1 to 11, wherein the addressing information of a breakout point for the call is or comprises an IP address of a tunnel endpoint of a tunnel for transferring one or more media or service data flows of the call in the satellite communication.

13. The method according to claim 12, wherein the tunnel is or comprises a point-to-point tunnel, and / or the tunnel endpoint is or comprises an intermediate user plane function at the satellite providing connectivity for the respective user equipment, and / or the satellite communication is or comprises call-related communication in an IP network in a single satellite, a single satellite constellation or across multiple satellite constellations.

14. The method according to any one of claims 1 to 13, wherein: the first user equipment comprises a local user equipment served by a first network comprising a network entity performing the method, and / or the second user equipment comprises a remote user equipment served by a second network, and / or the first user equipment comprises an originating or calling party of the call and the second user equipment comprises a terminating or called party of the call, or the second user equipment comprises an originating or calling party of the call and the first user equipment comprises a terminating or called party of the call, and / or the local breakout point is or comprises an intermediate user plane function at the satellite providing connectivity for the first user equipment.

15. The method according to claim 14, wherein: each one of the first network and the second network is or comprises an IP multimedia subsystem.

16. The method according to any one of claims 1 to 15, wherein: the call is an IP multimedia subsystem call or a multimedia telephony call.

17. The method according to any one of claims 1 to 16, wherein: the method is operable by or at a proxy call session control function, and / or the method is performed during or as part of an IP multimedia subsystem session and / or call or an establishment procedure thereof.

18. A method, comprising: obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, inserting the local breakout point for the call relating to the satellite providing connectivity for the first user equipment, retrieving the addressing information for the local breakout point, and reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

19. The method according to claim 18, wherein the request is obtained via policy control function services and / or rules, including policy and charging control rules, for the call from a policy control function of the network serving the first user equipment, and / or the addressing information for the local breakout point is reported to a policy control function of the network serving the first user equipment.

20. The method according to claim 18 or 19, comprising: allocating one or more intermediate user plane functions at the satellite providing connectivity for the first user equipment, and configuring the one or more intermediate user plane functions to act as a local packet data unit session anchor, wherein the addressing information for the local breakout point is retrieved from the local packet data unit session anchor.

21. The method according to claim 20, wherein the addressing information for the local breakout point is retrieved based on a packet detection rule and / or forwarding action rule with outer header creation request.

22. The method according to any one of claims 18 to 21, comprising: obtaining a request for updating the local breakout point for the call in accordance with addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the second user equipment, and updating a local packet data unit session anchor, corresponding to the local breakout point relating to the satellite providing connectivity for the first user equipment, in accordance with the addressing information for the remote breakout point for the call.

23. The method according to claim 22, wherein the request is obtained via an update of rules, including policy and charging control rules, for the call from a policy control function of a network serving the first user equipment, and / or the updating comprises providing the addressing information for the remote breakout point for the call.

24. The method according to any one of claims 18 to 23, wherein the obtaining comprises obtaining a request for insertion of the local breakout point for the call in accordance with addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the first user equipment, and the inserting comprises inserting the local breakout point for the call relating to the satellite providing connectivity for the first user equipment in accordance with the addressing information for the remote breakout point for the call.

25. The method according to any one of claims 18 to 24, wherein the addressing information of a breakout point for the call is or comprises an IP address of a tunnel endpoint of a tunnel for transferring one or more media or service data flows of the call in the satellite communication.

26. The method according to claim 25, wherein the tunnel is or comprises a point-to-point tunnel, and / or the tunnel endpoint is or comprises an intermediate user plane function at the satellite providing connectivity for the respective user equipment, and / or the satellite communication is or comprises call-related communication in an IP network in a single satellite, a single satellite constellation or across multiple satellite constellations.

27. The method according to any one of claims 18 to 26, wherein: the first user equipment comprises a local user equipment served by a first network comprising a network entity performing the method, and / or the second user equipment comprises a remote user equipment served by a second network, and / or the first user equipment comprises an originating or calling party of the call and the second user equipment comprises a terminating or called party of the call, or the second user equipment comprises an originating or calling party of the call and the first user equipment comprises a terminating or called party of the call, and / or the local breakout point is or comprises an intermediate user plane function at the satellite providing connectivity for the first user equipment.

28. The method according to claim 27, wherein: each one of the first network and the second network is or comprises an IP multimedia subsystem.

29. The method according to any one of claims 18 to 28, wherein: the call is an IP multimedia subsystem call or a multimedia telephony call.

30. The method according to any one of claims 18 to 29, wherein: the method is operable by or at a session management function, and / or the method is performed during or as part of an IP multimedia subsystem session and / or call or an establishment procedure thereof.

31. A method, comprising: obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for report of addressing information for a local breakout point for the call relating to a satellite providing connectivity for the first user equipment, and reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

32. The method according to claim 31, comprising: obtaining a packet detection rule and / or forwarding action rule with outer header creation request, wherein the reporting comprises reporting addressing information corresponding to the outer header being created in response to the outer header creation request.

33. The method according to claim 31 or 32, wherein: the method is operable by or at a user plane function and / or an intermediate user plane function at the satellite providing connectivity for the first user equipment, and / or the method is performed during or as part of an IP multimedia subsystem session and / or call or an establishment procedure thereof.

34. A method, comprising: obtaining, for a call between a first user equipment and a second user equipment via a satellite communication, a request for insertion of a local breakout point for the call relating to a satellite providing connectivity for the first user equipment and report of addressing information for the local breakout point, provisioning rules, including policy and charging control rules, for the call with regard to the request for insertion of the local breakout point for the call, obtaining the addressing information for the local breakout point, and reporting the addressing information for the local breakout point towards a network entity of a network serving the first user equipment.

35. The method according to claim 34, comprising: initiating policy control function services including authorization of resources for the call and insertion of the local breakout point for the call.

36. The method according to claim 34 or 35, wherein the addressing information for the local breakout point is obtained from a session management function of the network serving the first user equipment, and / or the addressing information for the local breakout point is reported towards a proxy call session control function of the network serving the first user equipment.

37. The method according to any one of claims 34 to 36, comprising: obtaining a request for authorization of resources for the call, in accordance with addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the second user equipment, and updating the rules, including the policy and charging control rules, for the call in accordance with addressing information for the remote breakout point.

38. The method according to any one of claims 34 to 36, wherein the request comprises a request for insertion of the local breakout point for the call in accordance with addressing information for a remote breakout point for the call relating to a satellite providing connectivity for the second user equipment.

39. The method according to any one of claims 34 to 38, wherein: the first user equipment comprises a local user equipment served by a first network comprising a network entity performing the method, and / or the second user equipment comprises a remote user equipment served by a second network, and / or the first user equipment comprises an originating or calling party of the call and the second user equipment comprises a terminating or called party of the call, or the second user equipment comprises an originating or calling party of the call and the first user equipment comprises a terminating or called party of the call, and / or the local breakout point is or comprises an intermediate user plane function at the satellite providing connectivity for the first user equipment.

40. The method according to claim 39, wherein: each one of the first network and the second network is or comprises an IP multimedia subsystem.

41. The method according to any one of claims 34 to 40, wherein: the call is an IP multimedia subsystem call or a multimedia telephony call.

42. The method according to any one of claims 34 to 41, wherein: the method is operable by or at a policy control function, and / or the method is performed during or as part of an IP multimedia subsystem session and / or call or an establishment procedure thereof.

43. 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 the method according to any one of claims 1 to 17.

44. 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 the method according to any one of claims 18 to 30.

45. 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 the method according to any one of claims 31 to 33.

46. 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 the method according to any one of claims 34 to 42.

47. A system comprising at least two of: an apparatus according to claim 43,. an apparatus according to claim 44, an apparatus according to claim 45, and an apparatus according to claim 46.

48. A computer program product comprising computer program code which, when the computer program code is executed on a computer, is configured to cause the computer to carry out the method according to any one of claims 1 to 17 or any one of claims 18 to 30 or any one of claims 31 to 33 or any one of claims 34 to 42.

Images