WO2025171604A1

WO2025171604A1 - Management of ue-satellite-ue communication

Info

Publication number: WO2025171604A1
Application number: PCT/CN2024/077293
Authority: WO
Inventors: Laurent Thiébaut; Hong Xie; Alexander Milinski; Xu Chen
Original assignee: Nokia Solutions and Networks Investment China Co Ltd; Nokia Technologies Oy
Current assignee: Nokia Solutions and Networks Investment China Co Ltd; Nokia Technologies Oy
Priority date: 2024-02-16
Filing date: 2024-02-16
Publication date: 2025-08-21
Anticipated expiration: 2026-08-16

Abstract

There are provided measures for (e. g. enabling/facilitating/realizing enhancements and/or improvements for) management 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, obtains first information regarding user equipment connectivity via satellite access for a first user equipment involved in a call, obtains second information regarding user equipment connectivity via satellite access for a second user equipment involved in the call, and detects, based on the first information and the second information, whether a satellite communication between the first user equipment and the second user equipment is feasible.

Description

MANAGEMENT OF UE-SATELLITE-UE COMMUNICATION

TECHNICAL FIELD

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) management of UE-satellite-UE communication, i.e. a satellite communication between a first user equipment and a second user equipment.

BACKGROUND

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/sor 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 (IoT) .

Such mobile or wireless communication technology and systems may support (communication via) non-terrestrial networks (NTNs) , i.e. any network that involves non-terrestrial 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 Project
5G            Fifth Generation
6G            Sixth Generation
AAA           Authorization Authentication Answer
AAR         Authorization Authentication Request
AF          Application Function
AGW         Access Gateway
AMF         Access and Mobility Management Function
ANI         Access Network Information
API         Application Programming Interface
DL          Downlink
EPS         Evolved Packet System
FAR         Forwarding Action Rule
GRE         Generic Routing Encapsulation
HSS         Home Subscriber Server
I/S-CSCF    Interrogating/Serving Call Session Control Function
I-UPF       Intermediate User Plane Function
IBCF        Interconnection Border Control Function
IMS         IP Multimedia Subsystem
IP          Internet Protocol
ISL         Inter-Satellite Link
L2TP        Layer 2 Tunneling Protocol
L-PSA       Local PDU Session Anchor
MME         Mobility Management Entity
MMTel       Multimedia Telephony
N3IW        Non-3GPP InterWorking Function
NAS         Non-Access Stratum
NAS-MM      NAS Mobility Management
NAS-SM      NAS Session Management
NPLI        Network Provided Location Information
NTN         Non-Terrestrial Network
P-CSCF      Proxy Call Session Control Function
PANI        P-Access-Network-Info
PCC         Policy and Charging Control
PCF         Policy Control Function
PDU         Packet Data Unit
PDR         Packet Detection Rule
PMIP        Proxy Mobile Internet Protocol
PSA         PDU Session Anchor
PtP         Point-to-Point
QoS         Quality of Service
RAA         Re-Authorization Answer
RAN          Radio Access Network
RAR          Re-Authorization Request
SDF          Service data Flow
SDN          Software Defined Networking
SDP          Session Description Protocol
SIP          Session Initiation Protocol
SMF          Session Management Function
TAS          Telephony Application Server
TNGF         Trusted Non-3GPP Gateway Function
TrGW         Transition Gateway
UDM          Unified Data Management
UDP          User Datagram Protocol
UE           User Equipment
UPF          User Plane Function
UL           Uplink
UL-CL        Uplink Classifier
URI          Uniform Resource Identifier
W-AGF        Wireless Access Gateway Function

SUMMARY

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.

Various example embodiments are set out in the claims.

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.

According to an example aspect, there is provided a method, comprising: obtaining first information regarding user equipment connectivity via satellite access for a first user equipment involved in a call, obtaining second information regarding user equipment connectivity via satellite access for a second user equipment involved in the call, and detecting, based on the first information and the second information, whether a satellite communication between the first user equipment and the second user equipment is feasible.

According to an example aspect, there is provided an apparatus, comprising: means for obtaining first information regarding user equipment connectivity via satellite access for a first user equipment involved in a call, means for obtaining second information regarding user equipment connectivity via satellite access for a second user equipment involved in the call, and means for detecting, based on the first information and the second information, whether a satellite communication between the first user equipment and the second user equipment is feasible.

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 first information regarding user equipment connectivity via satellite access for a first user equipment involved in a call, obtain second information regarding user equipment connectivity via satellite access for a second user equipment involved in the call, and detect, based on the first information and the second information, whether a satellite communication between the first user equipment and the second user equipment is feasible.

According to an example aspect, there is provided an apparatus, comprising: one more circuitry configured to obtain first information regarding user equipment connectivity via satellite access for a first user equipment involved in a call, obtain second information regarding user equipment connectivity via satellite access for a second user equipment involved in the call, and detect, based on the first information and the second information, whether a satellite communication between the first user equipment and the second user equipment is feasible.

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 first information comprises information on whether the first user equipment is provided with connectivity via satellite access and/or a first satellite constellation providing connectivity for the first user equipment and/or a first satellite constellation supporting satellite-based offloading of user plane traffic for the call,

the second information comprises information on whether the second user equipment is provided with connectivity via satellite access and/or a second satellite constellation providing connectivity for the second user equipment and/or a second satellite constellation supporting satellite-based offloading of user plane traffic for the call,

it is detected that the satellite communication is feasible when the first satellite constellation and the second satellite constellation match and support an inter-satellite link, or the first satellite constellation and the second satellite constellation do not match but support an inter-constellation inter-satellite link,

the method, functionality, operability or configuration comprises or enables: controlling establishment of the call and/or user plane transmission for the call via the satellite communication between the first user equipment and the second user equipment when it is detected that the satellite communication is feasible,

the controlling the user plane transmission for the call comprises offloading of user plane traffic of the call via the satellite communication,

the method, functionality, operability or configuration comprises or enables (or the obtaining the first information comprises) : making a subscription (subscribing) to a policy control function for the first information, and/or receiving, from the policy control function, notification of the first information, wherein the subscription may be made at network registration of the first user equipment or at call establishment time, and/or the subscription may last for duration of network registration of the first user equipment or duration of call-related session,

the method, functionality, operability or configuration comprises or enables (or the obtaining the first information comprises) : receiving, from the first user equipment, a message including the first information, wherein the message may be received at network registration of the first user equipment or at call establishment time, and/or the first information may be contained in a session initiation protocol message or header or a session description protocol message, and/or the first information may be contained in a P-Access-Network-Info header.

the method, functionality, operability or configuration comprises or enables (or the obtaining the second information comprises) : receiving, from a proxy call session control function of a network serving the second user equipment, a message including the second information, and/or the method, functionality, operability or configuration comprises or enables: removing the second information from the message, and/or forwarding the message to the first user equipment, wherein the second information may be contained in a session initiation protocol message or header or a session description protocol message, and/or the second information may be contained in a P-Access-Network-Info header,

the method, functionality, operability or configuration comprises or enables: sending, a proxy call session control function of a network serving the second user equipment, the first information, wherein the first information may be contained in a session initiation protocol message or header or a session description protocol message, and/or the first information may be contained in a P-Access-Network-Info header,

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, wherein each one of the first network and the second network may be or comprise an IP multimedia subsystem,

the call is an IP multimedia subsystem call or a multimedia telephony call,

the call is or comprises an IP multimedia subsystem session,

the method is operable by or at or the apparatus is (operated or located) in or at a proxy call session 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.

According to an example aspect, there is provided a method, comprising: obtaining information regarding user equipment connectivity via satellite access for a user equipment involved in a call, and providing the information to a network entity of a network serving the user equipment.

According to an example aspect, there is provided an apparatus, comprising: means for obtaining information regarding user equipment connectivity via satellite access for a user equipment involved in a call, and mans for providing the information to a network entity of a network serving the user equipment.

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 information regarding user equipment connectivity via satellite access for a user equipment involved in a call, and provide the information to a network entity of a network serving the user equipment.

According to an example aspect, there is provided an apparatus, comprising: one or more circuitry configured to obtain information regarding user equipment connectivity via satellite access for a user equipment involved in a call, and provide the information to a network entity of a network serving the user equipment.

the information comprises information on whether the user equipment is provided with connectivity via satellite access and/or a satellite constellation providing connectivity for the user equipment and/or a satellite constellation supporting satellite-based offloading of user plane traffic for the call,

the information is configured to assist the network entity in detecting whether a satellite communication between the user equipment and another user equipment is feasible,

the method, functionality, operability or configuration comprises or enables (or the obtaining the information comprises) : receiving the information via broadcast from a radio access network, wherein the radio access network may be a regenerative radio access network and/or a radio access network deployed on-board at least one satellite of a satellite constellation providing connectivity for first user equipment,

the method, functionality, operability or configuration comprises or enables (or the obtaining the information comprises) : receiving the information via signaling from an access and mobility management function, wherein the signaling from the access and mobility management function may be or comprise a non-access stratum mobility management signaling,

the method, functionality, operability or configuration comprises or enables (or the obtaining the information comprises) : receiving the information via signaling from a mobility management entity function, wherein the signaling from the mobility management entity function may be or comprise a non-access stratum mobility management signaling,

the method, functionality, operability or configuration comprises or enables (or the obtaining the information comprises) : receiving the information via signaling from a session management function, wherein the signaling from the session management function may be or comprise a non-access stratum session management signaling,

the method, functionality, operability or configuration comprises or enables: re-registering at the network whenever provisioning with connectivity via satellite access, provisioning with support of satellite-based offloading of user plane traffic for the call, and/or by a particular satellite constellation starts or stops,

the method, functionality, operability or configuration comprises or enables: sending, to the network entity, a message including the information, wherein the message may be sent at network registration of the user equipment or at call establishment time, and/or the information may be contained in a session initiation protocol message or header or a session description protocol message, and/or the information may be contained in a P-Access-Network-Info header,

the user equipment comprises an originating or calling party of the call or is a terminating or called party of the call,

the network is or comprises an IP multimedia subsystem,

the call is an IP multimedia subsystem call or a multimedia telephony call,

the call is or comprises an IP multimedia subsystem session,

the method is operable by or at or the apparatus is (operated or located) in or at the user equipment,

the network entity is or comprises a proxy call session control function,

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) .

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) .

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) .

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.

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) .

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

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

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

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

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

FIG. 2 shows a flowchart of an example method or process;

FIG. 3 shows a flowchart of an example method or process;

FIG. 4 shows an example procedure;

FIG. 5 shows an example IMS session establishment procedure at a terminating side of an IMS call;

FIG. 6 shows an example IMS session establishment procedure at an originating side of an IMS call;

FIG. 7 (including FIGs. 7A and 7B) shows an example end-to-end IMS session establishment procedure;

FIG. 8 shows a schematic block diagram of a structure of apparatuses;

FIG. 9 shows a schematic block diagram of a structure of apparatuses.

DETAILED DESCRIPTION

Various example embodiments are herein described with reference to particular non-limiting 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.

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 characteristic (s) , but every referenced embodiment or example embodiment may not necessarily include the particular feature (s) , structure (s) , or characteristic (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.

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.

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.

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 be understood/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.

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) .

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.

As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” 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.

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” .

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 or alternatively 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.

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.

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.

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 (management of) UE-satellite-UE communication, i.e. a satellite communication between a first user equipment and a second user equipment.

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.

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.

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 therein 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.

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.

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

As shown in FIG. 1, the system configuration is composed of two portions on the left-hand 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 portion, 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.

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 (terrestrial, ground or earth-bound) 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 user plane traffic may be exchanged via the respective (non-terrestrial, airborne or satellite-based) components (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

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.

It is to be noted that an (IMS/MMTel) call relates to and/or is based 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.

Example embodiments relate to detection whether UE-satellite-UE communication (i.e. user plane traffic offloading) is possible. As detailed below, example embodiments can facilitate to identify if an originating or calling party and a terminating or called party are under satellite access enabling UE-satellite-UE communication. Thereby, it can be ensured that user plane traffic offloading is initiated/established for a call with the involved parties being under coverage with a suitable regenerative satellite or satellite constellation (s) , while avoiding user plane traffic offloading for/a call with two involved parties being not under coverage of a suitable regenerative satellite or satellite constellation (s) . Stated in other words, example embodiments can facilitate to determine when to try to use an IP network, which is built by an ISL or set of ISLs at a satellite or satellite constellation (s) and provides for possible local or satellite traffic switching, for the transfer of user plane traffic of a call.

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

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) .

As shown in FIG. 2, the method or process comprises a step/operation (S110) of obtaining first information regarding user equipment connectivity via satellite access for a first user equipment involved in a call, a step/operation (S120) of obtaining second information regarding user equipment connectivity via satellite access for a second user equipment involved in the call, and a step/operation (S130) of detecting, based on the first information and the second information, whether a satellite communication between the first user equipment and the second user equipment is feasible.

The first information may comprise information on whether the first user equipment is provided with connectivity via satellite access and/or a first satellite constellation providing connectivity for the first user equipment and/or a first satellite constellation supporting satellite-based offloading of user plane traffic for the call. The second information may comprise information on whether the second user equipment is provided with connectivity via satellite access and/or a second satellite constellation providing connectivity for the second user equipment and/or a second satellite constellation supporting satellite-based offloading of user plane traffic for the call. For example, any such information may comprise a satellite ID and/or a satellite constellation ID and/or property/attribute information for one or more satellites or satellite constellations.

In the detecting step/operation (S130) , it may be detected that the satellite communication is feasible when (i) the first satellite constellation and the second satellite constellation match (i.e. are the same) and support an inter-satellite link (ISL) , and/or (ii) the first satellite constellation and the second satellite constellation do not match but support an inter-constellation inter-satellite link (ISL) . Matching satellite constellations also encompass matching satellites, i.e. when the two user equipments are provided with connectivity by the same satellite and/or same satellite constellation. For example, a satellite communication may be realized by a single/common satellite serving both user equipments, a single/common satellite constellation serving both user equipments, or different/distinct satellite constellations serving the two user equipments, when these different/distinct satellite constellations support satellite-based offloading of user plane traffic for the call (e.g. are capable of interacting, establishing an IP network via ISL (s) , or the like) . Such information may be (at least partly) provided by the aforementioned first/second information and/or (eta least partly) available at the P-CSCF.

As shown by dashed line, the method or process may comprise a step/operation (S140) of controlling establishment of the call and/or user plane transmission for the call via the satellite communication between the first user equipment and the second user equipment when it is detected that the satellite communication is feasible. Controlling user plane transmission for the call may comprise offloading of user plane traffic of the call via the satellite communication. When it is detected that the satellite communication is not feasible, no further step/operation regarding establishment of a satellite communication or otherwise specific for satellite communication may take place, or a step/operation of denying or preventing call establishment for a satellite communication may be performed, and/or one or more corresponding notifications may be made, or the like. In such case, a call between the first user equipment and the second user equipment may be (tried to be) established in a ground-based manner, i.e. with/including terrestrial transmission, such as e.g. with the following call flow (referring to FIG. 1) : left-hand UE –left-hand satellite –left-hand (terrestrial, ground or earth-bound) 5G/NR and IMS network –right-hand (terrestrial, ground or earth-bound) 5G/NR and IMS networks –right-hand satellite –right-hand UE.

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 UE as an example of a network function, entity or element of a communication system. The UE 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) .

As shown in FIG. 3, the method or process comprises a step/operation (S210) of obtaining information regarding user equipment connectivity via satellite access for a user equipment involved in a call, and a step/operation (S220) of providing the information to a network entity of a network serving the user equipment.

The information may comprise information on whether the user equipment is provided with connectivity via satellite access and/or a satellite constellation providing connectivity for the user equipment and/or a satellite constellation supporting satellite-based offloading of user plane traffic for the call. The information may be configured to assist the network entity (which may be a P-CSCF) in detecting whether a satellite communication between the user equipment and another user equipment is feasible. For example, such information may comprise a satellite ID and/or a satellite constellation ID and/or property/attribute information for one or more satellites or satellite constellations.

Although not shown in FIG. 3, the UE may re-register at the network whenever provisioning with connectivity via satellite access, provisioning with support of satellite-based offloading of user plane traffic for the call, and/or by a particular satellite constellation starts or stops.

FIG. 4 shows an example procedure according to at least one example embodiment. The procedure of FIG. 4 basically corresponds to an overall view/perspective on the interaction/cooperation between a local P-CSCF and a remote a P-CSCF together with a PCF and/or a UE (which is the local UE, from the perspective of the local P-CSCF and the PCF) in the course of call/session establishment, wherein the local P-CSCF operates in accordance with the method or process of FIG. 2, and the UE may operate in accordance with the method or process of FIG. 3. Accordingly, reference is made to the above description of FIGs. 2 and 3 for details of the individual operations of the network functions, entities or elements.

As shown in FIG. 4, there may be various alternatives for the local P-CSCF to obtain the first information.

In an alternative, the local P-CSCF, in, for or as part of obtaining the first information, may make a subscription (i.e. subscribe) to a PCF for the first information and receive notification of the first information from the PCF. The subscription may be made at network registration of the first user equipment or at call establishment time (e.g., time when call establishment occurs) . The subscription may last for duration of network registration of the first user equipment or duration of call-related session.

In another alternative, the local P-CSCF, in, for or as part of obtaining the first information, may receive a message including the first information from the UE. The message may be sent by the UE and/or received at the local P-CSCF at network registration of the first user equipment or at call establishment time (e.g., time when call establishment occurs) . The first information may be contained in a SIP message or header or an SDP message, and/or the first information may be contained in a P-Access-Network-Info (PANI) header. Before providing the first information to the local P-CSCF, the UE may obtain the information (or part thereof) in various ways, e.g. by receiving the information via broadcast from a RAN (which may be a regenerative RAN and/or a RAN deployed on-board at least one satellite of a satellite constellation providing connectivity for first user equipment) , receiving the information via signaling from an AMF (wherein this signaling may be or comprise a non-access stratum mobility management (NAS-MM) signaling) , or receiving the information via signaling from a MME (wherein this signaling may be or comprise a non-access stratum mobility management (NAS-MM) signaling) , or receiving the information via signaling from a SMF (wherein this signaling may be or comprise a non-access stratum session management (NAS-SM) signaling) .

In, for or as part of obtaining the second information, the local P-CSCF may receive a message including the second information from the remote P-CSCF. The second information may be contained in a SIP message or header or an SDP message, and/or the second information may be contained in a P-Access-Network-Info header (PANI) .

The message containing the second information, after being received from the remote P-CSCF, may be forwarded to the UE after removing the second information (e.g. a header containing the second information) from the message.

Then, the local P-CSCF may detect whether a satellite communication between the first user equipment and the second user equipment is feasible, and control establishment of the call and/or user plane transmission for the call via the satellite communication between the first user equipment and the second user equipment when it is detected that the satellite communication is feasible.

Also, the local P-CSCF may provide the first information to the remote P-CSF. In, for or as part of providing the first information, the local P-CSCF may send a message including the first information to the remote P-CSCF. The first information may be contained in a SIP message or header or an SDP message, and/or the first information may be contained in a P-Access-Network-Info header (PANI) .

It is to be noted that the procedure of FIG. 4 is shown in an illustrative and exemplary manner, without limitation. For example, either one or both of the two alternatives for obtaining the first information may take place, certain sequences of operations may be different, or the like. As an example, the message with the first information may be transmitted from the local P-CSCF to the remote P-CSCF before the message with the second information is received at the local P-CSCF from the remote P-CSCF, the message with the second information may be received at the local P-CSCF from the remote P-CSCF before or during obtaining the first information from the UE and/or the PCF, or the like. Any one of the methods or processes of FIGs. 2 and 3 and the procedure of FIGS. 4 may be performed during or as part/portion 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) .

It is to be noted that the procedure of FIGs. 4 is described in the context/course of call/session establishment, but this is by way of example only, without limitation. The procedure of FIG. 4 can take place at any (other) time or at any (other) stage of a call or session. For example, the procedure of FIG. 4 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 the procedure of FIG. 4, yet without a call establishment initiation step, can take place or be carried out. That is, the method or process at any one of the local P-CSCF, the remote P-CSCF, the PCF and the UE 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.

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.

FIG. 5 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.

Although not shown in FIG. 5, the procedure starts with the following initial step.

0. At IMS initial registration onto the P-CSCF, the P-CSCF subscribes (e.g. by Npcf_PolicyAuthorization_Subscribe targeting the UE IP address in the contact header) onto the PCF about the UE connectivity via satellite connection (e.g. Event = [Access Network Information Reporting-> “Current Satellite ID+Satellite Constellation ID” ] ) . At subscription it gets notified (whether/that) the UE is served by a satellite/satellite constellation and later it gets notified (whether/that) the UE has changed the satellite/satellite constellation or, stated in other words, the serving satellite/satellite constellation for the UE has changed (e.g. by Npcf_PolicyAuthorization_Notify) . The P-CSCF stores the association between the UE and a satellite/satellite constellation.

As shown in FIG. 5, the procedure comprises the following steps.

1. The P-CSCF receives the SDP parameters defined by the originator together with originated side IMS core generated SIP header e.g. PANI indicating that the originator is served by a satellite of a given constellation (Satellite ID+ Satellite constellation ID) . The following assumes 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) , which may be detected based on a match between the remote UE information received in PANI and the local UE information retrieved at step 0.

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 (removing any SIP header e.g. PANI indicating that the other party is served by a satellite of a given constellation received from the other party) .

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) ,

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_PolicyAuthorization_Create 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.

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] .

11a. 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 11a occurs, the P-CSCF acknowledges the receipt of Diameter RAR.

13. If step 11 occurs (or step 11a for the Rx case) , the P-CSCF forwards the SDP answer and includes the network provided location information (ANI) in the next SIP message the P-CSCF sends towards the IMS core network.

As shown in FIG. 5, the procedure may further comprise the following steps.

14. The terminating P-CSCF receives SDP offer with network provided location information (ANI) of the other party.

15. The P-CSCF provides (via PCF) the SMF with the network provided location information (ANI) of the other party. 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) (previously inserted) : the SMF updates the corresponding FAR/Forwarding Parameters / Outer Header Creation accordingly.

FIG. 6 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 originating P-CSCF and PCF.

Although not shown in FIG. 6, the procedure starts with the following initial step.

As shown in FIG. 6, 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.

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 together with originated side IMS core generated SIP header e.g. PANI indicating that the originator is served by a satellite of a given constellation (Satellite ID+ Satellite constellation ID) . (This step corresponds to step 1 in FIG. 5 on the terminating side) .

4. The P-CSCF gets the negotiated SDP parameters from the terminating side through SIP signaling interaction together with SIP header e.g. PANI indicating that the terminating UE is served by a satellite of a given constellation (Satellite ID+ Satellite constellation ID (This corresponds to Step13 in FIG. 5 on the terminating side) .

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) .

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.

11a. 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 11a occurs, the P-CSCF acknowledges the receipt of Diameter RAR.

13. If step 11 occurs (step 11a for Rx case) , the P-CSCF forwards the network provided location information in a subsequent SIP message to IMS core network. The P-CSCF, based on local configuration, may also include the EPS fallback indication, if received.

FIG. 7 (including FIGs. 7A and 7B) shows an example end-to-end IMS session establishment procedure. The procedure of FIG. 7 corresponds to a combination of the procedures of FIGs. 5 and 6, and is provided for facilitating an overview of an end-to-end call (establishment) flow. Accordingly, reference is made to the description of FIGs. 5 and 6 for details.

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

The P-CSCF (e.g. upon UE registration) subscribes to the PCF for the UE connectivity via satellite access (i.e. satellite and/or satellite constellation) and generates information about UE accessing the network via a satellite and/or satellite constellation.

The UE generates information in SIP signaling about UE accessing the network via a satellite and/or satellite constellation. This may be based on RAN broadcast information or on information sent to the UE over NAS signaling. The UE provides this information to the P-CSCF. Optionally, this information may be generated at/by the UE when the UE registers in the (IMS) network, and may be provided over SIP (e.g. in PANI) .

Information about UE accessing the network via a satellite and/or satellite constellation is exchanged between P-CSCF (s) (of parties involved in a call/session) over SIP (e.g. in PANI) but shall not be transferred to the remote UE (but removed before message forwarding to the UE) .

When parties involved in a session are served by one or more satellites and/or one or more satellite constellations that can exchange user plane traffic over ISL (s) , some local traffic switching (e.g. at a L-PSA of a corresponding satellite) may be applied.

The SMF supports necessary PCC rules and procedures to support the actions described herein (above) .

According to one or more example embodiments, for the UE to detect/identify that a satellite and/or satellite constellation supports UE-UE communication via satellite offload and UE-satellite-UE communication is supported, it may be that:

- the information is broadcast over the air by the RAN, and/or

- AMF or SMF or MME provides the information to the UE vis NAS signalling, e.g. via NAS MM signaling (NAS MM via registration accept) for AMF or MME, NAS SM signaling (via PDU session related signaling) for SMF.

In this option:

- The UE may re-REGISTER when it starts and stops being served by a satellite and/or satellite constellation.

- The information that a UE is served by satellite, i.e. (a satellite of a) satellite constellation and by which satellite and/or satellite combination may be carried in a SIP header that is sent (for an IMS call) up to the other party’s P-CSCF but shall not be sent to the other UE.

According to one or more example embodiments, upon UE registration, the P-CSCF subscribes to the PCF for the UE connectivity via a satellite and/or satellite constellation. At subscription time, the P-CSCF gets notified (whether/that) the UE is served by which satellite/satellite constellation, and then the P-CSCF gets notified when serving satellite/satellite constellation changes for the UE. The subscription may be lasting for the whole registration of the UE or for the duration of every SIP session only.

According to one or more example embodiments, it may be assumed that the AMF notifies the SMF (that notifies the PCF) about whether a UE is served by a given satellite/satellite constellation. Further, it may be assumed that the ISL (s) can be within the same satellite, the same satellite constellation or across different constellations, depending on the satellite operator’s deployments.

According to one or more example embodiments, the information that a UE is served by satellite, i.e. (a satellite of) a satellite constellation and by which satellite and/or satellite combination may be carried in a SIP header that is sent (for an IMS call) between the originating and the terminating party’s P-CSCF but shall not be sent to the other UE. Thus, this information may be added by P-CSCF of one party (of the call) sent up to the other party’s P-CSCF and removed by this other party’s P-CSCF.

According to one or more example embodiments, based on SIP header information associated with the remote party of a call and information received from the PCF for the local UE, a P-CSCF may detect that both parties of a call are served by the same satellite, the same satellite constellation or satellite constellations that supports inter-constellation ISL (s) . This applies for both originating and terminating P-CSCF.

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 header information regarding UE connectivity via satellite access capable of UE-satellite-UE be sent to the other party of the call.

According to one or more example embodiments, e.g. in the configuration of FIG. 1, the P-CSCF in the IMS (at either side) may, upon UE registration, subscribe onto the PCF for the local UE connectivity via satellite access capable of UE-satellite-UE. Further, the P-CSCF may generate/receive a SIP header, e.g. PANI, related to the local/remote connectivity via satellite access capable of UE-satellite-UE, but shall ensure that such header is not sent out to the local UE. Further, the P-CSCF may, based on the SIP header, e.g. PANI, associated with the remote party of a call and the information received from the PCF for the local UE, detect that both parties of a call are served by the same satellite, the same satellite constellation or satellite constellations that support traffic switching at satellite network level.

According to one or more example embodiments, e.g. in the configuration of FIG. 1, the PCF (at either side) may support subscription for the UE connectivity via a satellite and/or satellite constellation.

According to one or more example embodiments, e.g. in the configuration of FIG. 1, the SMF (at either side) may notify the PCF about when/whether a UE is served by a given satellite/satellite constellation.

In the option where the UE generate SIP header information regarding UE connectivity via satellite access capable of UE-satellite-UE communication, according to one or more example embodiments, e.g. in the configuration of FIG. 1, the UE (at either side) may receive information that the constellation supports UE-satellite-UE communication via satellite offload, either broadcast over the air by the RAN or provided by AMF or SMF or MME to the UE.via NAS signalling.

According to one or more example embodiments, e.g. in the configuration of FIG. 1, the UE (at either side) , upon UE IMS REGISTER, i.e. when the UE registers at the IMS network, the UE may provide in SIP header, e.g. PANI, information on a satellite and/or satellite constellation that is providing connectivity to the UE. The UE may support SIP header, e.g. PANI, to send access information such as e.g. satellite ID and/or satellite constellation ID. The UE may re-REGISTER when it starts and stops being served by a satellite and/or satellite constellation.

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.

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.

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 7. 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.

In Figures 8 and 9, 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 8 and 9, 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.

Further, in Figures 8 and 9, 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.

FIG. 8 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.

As indicated in FIG. 8, according to at least one example embodiment, an apparatus 800 may comprise or realize at least one processor 810 and at least one memory 820 and at least one interface 830, which may be operationally connected or coupled, for example by a bus 840 or the like, respectively. The processor 810 and the memory 820 may be included in or be part of processing circuitry.

The processor 810 and/or the interface 830 of the apparatus 800 may also include a modem or the like to facilitate communication over a (e.g., hardwire or wireless) link, respectively. The interface 830 of the apparatus 800 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 830 of the apparatus 800 is generally configured to communicate with 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.

The memory 820 of the apparatus 800 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 820 of the apparatus 800 may (comprise a database to) store any data, information, or the like, which is used in the operation of the apparatus.

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.

In view of the above, the illustrated apparatus 800 can be used in practicing one or more of the example embodiments, as described herein.

According to at least one example embodiment, the illustrated apparatus 800 may represent or realize/embody a (e.g., part of a) P-CSCF. Hence, the apparatus 800 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, 2 and 4 to 7.

Accordingly, the apparatus 800 may be caused or the apparatus 800 or its at least one processor 810 (e.g., together with instructions stored in its at least one memory 820) may be configured to obtaining first information regarding user equipment connectivity via satellite access for a first user equipment involved in a call, to obtaining second information regarding user equipment connectivity via satellite access for a second user equipment involved in the call, and to detecting, based on the first information and the second information, whether a satellite communication between the first user equipment and the second user equipment is feasible.

Further, the apparatus 800 may be caused or the apparatus 800 or its at least one processor 810 (e.g., together with instructions stored in its at least one memory 820) may be configured to perform any one of the methods, functionalities or operations, as described with respect to a P-CSCF.

According to at least one example embodiment, the illustrated apparatus 800 may represent or realize/embody a (e.g., part of a) UE. Hence, the apparatus 800 may be configured to perform a procedure and/or exhibit a functionality and/or implement a mechanism, as described (e.g., for a UE) in any one of FIGS. 1, 3 and 4 to 7.

Accordingly, the apparatus 800 may be caused or the apparatus 800 or its at least one processor 810 (e.g., together with instructions stored in its at least one memory 820) may be configured to obtaining information regarding user equipment connectivity via satellite access for a user equipment involved in a call, and to provide the information to a network entity of a network serving the user equipment.

Further, the apparatus 800 may be caused or the apparatus 800 or its at least one processor 810 (e.g., together with instructions stored in its at least one memory 820) may be configured to perform any one of the methods, functionalities or operations, as described with respect to a UE.

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. 8, e.g., by one or more processors 810, one or more memories 820, one or more interfaces 830, or any combination thereof.

FIG. 9 shows a schematic diagram illustrating a structure of apparatuses according to at least one example embodiment.

As shown in FIG. 9, an apparatus 910 according to at least one example embodiment may represent or realize/embody a (e.g., part of a) P-CSCF. Hence, the apparatus 910 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, 2 and 4 to 7.

The apparatus 910 may comprise (at least) one or more unit/means/circuitry, denoted by first obtaining section 911, which represent any implementation for (or configured to) obtaining (obtain) first information regarding user equipment connectivity via satellite access for a first user equipment involved in a call, one or more unit/means/circuitry, denoted by second obtaining section 912, which represent any implementation for (or configured to) obtaining (obtain) second information regarding user equipment connectivity via satellite access for a second user equipment involved in the call, and one or more unit/means/circuitry, denoted by detecting section 911, which represent any implementation for (or configured to) detecting (detect) , based on the first information and the second information, whether a satellite communication between the first user equipment and the second user equipment is feasible.

Further, the apparatus 910 may comprise one or more unit/means/circuitry, denoted by controlling section 914, which represent any implementation for (or configured to) control (controlling) establishment of the call and/or user plane transmission for the call via the satellite communication between the first user equipment and the second user equipment when it is detected that the satellite communication is feasible. Further, the apparatus 910 may comprise one or more unit/means/circuitry, denoted by subscribing section 915, which represent any implementation for (or configured to) subscribe (subscribing) to a policy control function for the first information, and one or more unit/means/circuitry, denoted by receiving section 916, which represent any implementation for (or configured to) receive (receiving) , from the policy control function, notification of the first information. Additionally or alternatively, the receiving section 916 may represent any implementation for (or configured to) receive (receiving) , from a proxy call session control function of a network serving the second user equipment, a message including the second information. Further, the apparatus 910 may comprise one or more unit/means/circuitry, denoted by removing section 917, which represent any implementation for (or configured to) remove (removing) second information from a message, and one or more unit/means/circuitry, denoted by forwarding section 917, which represent any implementation for (or configured to) forward (forwarding) a message to the first user equipment. Further, the apparatus 910 may comprise one or more unit/means/circuitry, denoted by sending section 919, which represent any implementation for (or configured to) send (sending) , to a proxy call session control function of a network serving the second user equipment, the first information.

As shown in FIG. 9, an apparatus 920 according to at least one example embodiment may represent or realize/embody a (e.g., part of a) UE. Hence, the apparatus 920 may be configured to perform a procedure and/or exhibit a functionality and/or implement a mechanism, as described (e.g., for a UE) in any one of FIGS. 1, 3 and 4 to 7.

The apparatus 920 may comprise (at least) one or more unit/means/circuitry, denoted by obtaining section 921, which represent any implementation for (or configured to) obtaining (obtain) information regarding user equipment connectivity via satellite access for a user equipment involved in a call, and one or more unit/means/circuitry, denoted by providing section 922, which represent any implementation for (or configured to) provide (providing) the information to a network entity of a network serving the user equipment.

Further, the apparatus 920 may comprise one or more unit/means/circuitry, denoted by receiving section 923, which represent any implementation for (or configured to) receive (receiving) the information. Further, the apparatus 920 may comprise one or more unit/means/circuitry, denoted by re-registering section 924, which represent any implementation for (or configured to) re-register (re-registering) at the network whenever provisioning with connectivity via satellite access, provisioning with support of satellite-based offloading of user plane traffic for the call, and/or by a particular satellite constellation starts or stops. Further, the apparatus 920 may comprise one or more unit/means/circuitry, denoted by sending section 925, which represent any implementation for (or configured to) send (sending) , to the network entity, a message including the information.

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 7, respectively.

According to some 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.

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.

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.

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.

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.

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 or a 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.

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.

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.

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.

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.

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.

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.

In view of the above, there are provided measures for (e.g. enabling/facilitating/realizing enhancements and/or improvements for) management 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, obtains first information regarding user equipment connectivity via satellite access for a first user equipment involved in a call, obtains second information regarding user equipment connectivity via satellite access for a second user equipment involved in the call, and detects, based on the first information and the second information, whether a satellite communication between the first user equipment and the second user equipment is feasible. 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

A method, comprising:

obtaining first information regarding user equipment connectivity via satellite access for a first user equipment involved in a call,

obtaining second information regarding user equipment connectivity via satellite access for a second user equipment involved in the call, and

detecting, based on the first information and the second information, whether a satellite communication between the first user equipment and the second user equipment is feasible.
The method according to claim 1, wherein:

the first information comprises information on whether the first user equipment is provided with connectivity via satellite access and/or a first satellite constellation and/or a first satellite constellation supporting satellite-based offloading of user plane traffic for the call, and

the second information comprises information on whether the second user equipment is provided with connectivity via satellite access and/or a second satellite constellation and/or a second satellite constellation supporting satellite-based offloading of user plane traffic for the call.
The method according to claim 2, wherein it is detected that the satellite communication is feasible when

the first satellite constellation and the second satellite constellation match and support an inter-satellite link, or

the first satellite constellation and the second satellite constellation do not match but support an inter-constellation inter-satellite link.
The method according to any one of claims 1 to 3, comprising:

controlling establishment of the call and/or user plane transmission for the call via the satellite communication between the first user equipment and the second user equipment when it is detected that the satellite communication is feasible.
The method according to claim 4, wherein:

the controlling the user plane transmission for the call comprises offloading of user plane traffic of the call via the satellite communication.
The method according to any one of claims 1 to 5, comprising:

making a subscription to a policy control function for the first information, and

receiving, from the policy control function, notification of the first information.
The method according to claim 6, wherein

the subscription is made at network registration of the first user equipment or at call establishment time, and/or

the subscription lasts for duration of network registration of the first user equipment or duration of call-related session.
The method according to any one of claims 1 to 5, comprising:

receiving, from the first user equipment, a message including the first information.
The method according to claim 8, wherein

the message is received at network registration of the first user equipment or at call establishment time, and/or

the first information is contained in a session initiation protocol message or header or a session description protocol message, and/or

the first information is contained in a P-Access-Network-Info header.
The method according to any one of claims 1 to 9, comprising:

receiving, from a proxy call session control function of a network serving the second user equipment, a message including the second information.
The method according to claim 10, comprising:

removing the second information from the message, and

forwarding the message to the first user equipment.
The method according to claim 10 or 11, wherein:

the second information is contained in a session initiation protocol message or header or a session description protocol message, and/or

the second information is contained in a P-Access-Network-Info header.
The method according to any one of claims 1 to 12, comprising:

sending, to a proxy call session control function of a network serving the second user equipment, the first information.
The method according to claim 13, wherein:

the first information is contained in a session initiation protocol message or header or a session description protocol message, and/or

the first information is contained in a P-Access-Network-Info header.
The method according to any one of claims 1 to 14, 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.
The method according to claim 15, wherein:

each one of the first network and the second network is or comprises an IP multimedia subsystem.
The method according to any one of claims 1 to 16, wherein:

the call is an IP multimedia subsystem call or a multimedia telephony call, and/or

the call is or comprises an IP multimedia subsystem session.
The method according to any one of claims 1 to 17, 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.
A method, comprising:

obtaining information regarding user equipment connectivity via satellite access for a user equipment involved in a call, and

providing the information to a network entity of a network serving the user equipment.
The method according to claim 19, wherein:

the information comprises information on whether the user equipment is provided with connectivity via satellite access and/or a satellite constellation and/or a satellite constellation supporting satellite-based offloading of user plane traffic for the call, and/or

the information is configured to assist the network entity in detecting whether a satellite communication between the user equipment and another user equipment is feasible.
The method according to claim 19 or 20, comprising:

receiving the information via broadcast from a radio access network, or

receiving the information via signaling from an access and mobility management function, or

receiving the information via signaling from a mobility management entity function, or

receiving the information via signaling from a session management function.
The method according to claim 21, wherein

the radio access network is a regenerative radio access network and/or a radio access network deployed on-board at least one satellite of a satellite constellation providing connectivity for first user equipment, or

the signaling from the access and mobility management function is or comprises a non-access stratum mobility management signaling, or

the signaling from the mobility management entity function is or comprises a non-access stratum mobility management signaling, or

the signaling from the session management function is or comprises a non-access stratum session management signaling.
The method according to any one of claims 19 to 22, comprising:

re-registering at the network whenever provisioning with connectivity via satellite access, provisioning with support of satellite-based offloading of user plane traffic for the call, and/or by a particular satellite constellation starts or stops.
The method according to any one of claims 19 to 23, comprising:

sending, to the network entity, a message including the information.
The method according to claim 24, wherein

the message is sent at network registration of the user equipment or at call establishment time, and/or

the information is contained in a session initiation protocol message or header or a session description protocol message, and/or

the information is contained in a P-Access-Network-Info header.
The method according to any one of claims 19 to 25, wherein:

the user equipment comprises an originating or calling party of the call or is a terminating or called party of the call, and/or

the network is or comprises an IP multimedia subsystem.
The method according to any one of claims 19 to 26, wherein:

the call is an IP multimedia subsystem call or a multimedia telephony call, and/or

the call is or comprises an IP multimedia subsystem session.
The method according to any one of claims 19 to 27, wherein:

the method is operable by or at the user equipment, and/or

the network entity is or comprises 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.
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 18.
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 19 to 28.
A system comprising at least:

an apparatus according to claim 29, and.

an apparatus according to claim 30.
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 18 or 19 to 28.