WO2024033833A1

WO2024033833A1 - Apparatus, method, and computer program

Info

Publication number: WO2024033833A1
Application number: PCT/IB2023/058051
Authority: WO
Inventors: Parthasarathi RAVINDRAN; Devaki Chandramouli; Markus Sakari ISOMÄKI
Original assignee: Nokia Technologies Oy
Priority date: 2022-08-09
Filing date: 2023-08-09
Publication date: 2024-02-15

Abstract

There is provided an apparatus, method, and computer program for a first policy control function that cause the first policy control function to: receive, from a network exposure interface, at least one first request to determine a first policy in respect of resources to be reserved for a first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set; and abstain from determining said first policy until the number of at least one first requests received equals the number of user equipment comprised in the first set.

Description

APPARATUS, METHOD, AND COMPUTER PROGRAM

Related Applications

[0001] This patent application claims the benefit of priority of Indian Provisional Patent Application No. 202241045428 filed August 9, 2022, the contents of which are hereby incorporated by reference as if reproduced in their entirety.

Technical Field

[0002] The examples described herein generally relate to apparatus, methods, and computer programs, and more particularly (but not exclusively) to apparatus, methods and computer programs for wireless communication systems.

Background

[0003] A communication system can be seen as a facility that enables communications between two or more entities such as communication devices, base stations and/or other network nodes by providing links between the various entities involved in a communications path.

[0004] The communication system may be a wireless communication system that comprises various network. Examples of networks in a wireless communication system comprise public land mobile networks (PLMN) operating based on radio access technology specified by various standards organizations such as those provided by 3GPP, radio access networks, satellite-based communication networks and different wireless local networks, for example wireless local area networks (WLAN). The radio access network can typically be divided into cells, and are therefore often referred to as cellular networks.

[0005] The wireless communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and/or parameters which shall be used for the connection are also typically defined. Examples of standard are the so-called 4G, 5G, and 6G standards.

Summary

[0006] According to a first aspect, there is provided a method for a network exposure function, the method comprising: receiving, from an application function, a reservation request to reserve resources for an application function session, the reservation request comprising an indication of a plurality of user equipment for which resources are to be reserved, and an indication that the plurality of user equipment are to be jointly admitted and/or their resources are to be jointly retained; determining that a first policy control function is associated with a first set of user equipment of the plurality of user equipment; and signalling, to the first policy control function, at least one first request to determine a first policy in respect of resources to be reserved for the first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set.

[0007] The method may comprise: determining that a second policy control function is associated with a second set of user equipment of the plurality of user equipment; and signalling, to the second policy control function, at least one second request to determine a second policy in respect of resources to be reserved for the second set of user equipment, the at least one second request comprising an indication of a number of user equipment comprised in the second set.

[0008] The method may comprise: receiving, from the first and second policy control functions, respective indications that the first and second sets of user equipment were successfully jointly admitted; and signalling, to the application function, an indication that the plurality of user equipment were successfully jointly admitted.

[0009] The method may comprise receiving, from the first policy control function, an indication that the first set of user equipment were successfully jointly admitted; receiving, from the second policy control function, an indication that the second set of user equipment were not successfully jointly admitted; and signalling, to the application function, an indication that the plurality of user equipment were not successfully jointly admitted.

[0010] The method may comprise signalling, to the first policy control function, an indication that the plurality of user equipment were not successfully jointly admitted.

[0011] Signalling the at least one first request may comprise signalling a plurality of first requests for resources to be reserved, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment.

[0012] The method may comprise: receiving, from the first policy control function, an indication that resources could not be retained in respect of at least one of the first set of user equipment; identifying all policy control functions that serve a flow group associated with the first set of user equipment; and signalling, to at least one of said all policy control functions, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment.

[0013] The method may comprise: signalling, to the application function, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment. [0014] The method may comprise: subsequent to signalling said at least one of said policy control functions, receiving from said at least one of said policy control functions, an indication that resources could not be retained in respect of at least one of the plurality of user equipment served by the said at least one of said policy control functions.

[0015] The at least one first request may comprise at least one of: an identifier of at least one of the user equipment comprised in the first set; an identifier of a flow group to which the first set of user equipment are associated; and an indication that the user equipment in the first set are to be jointly admitted.

[0016] The at least one first request may relate to the provision of a multi-modality service.

[0017] The at least one first request may comprise support information for configuring for a Low Latency, Low Loss, Scalable Throughput data traffic.

[0018] According to a second aspect, there is provided a method for a first policy control function, the method comprising: receiving, from a network exposure interface, at least one first request to determine a first policy in respect of resources to be reserved for a first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set; and abstaining from determining said first policy until the number of at least one first requests received equals the number of user equipment comprised in the first set.

[0019] The method may comprise: attempting to determine said first policy when the number of at least one first requests received equals the number of user equipment comprised in the first set; and when the first policy is successfully determined, signalling to the network exposure function an indication that the first set of user equipment have been successfully jointly admitted; and when the first policy is not successfully determined, signalling to the network exposure function an indication that the first set of user equipment have not been successfully jointly admitted.

[0020] The method may comprise, when the first policy is successfully determined: providing the first policy to a session management function; receiving, from the session management function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment; and signalling, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment.

[0021] The method may comprise, when the first policy is successfully determined: receiving, from the network exposure function, an indication that at least one user equipment associated with a same flow group as the first set of user equipment has not had resources retained in respect of it; signalling, to a session management function, an instruction to release and/or reconfigure resources for each user equipment in the first set of user equipment; and signalling, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment. [0022] The receiving the at least one first request may comprise receiving a plurality of first requests for resources to be reserved and/or retained, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment.

[0023] The at least one first request may comprise at least one of: an identifier of at least one of the user equipment comprised in the first set; an identifier of a flow group to which the first set of user equipment are associated; and an indication that the user equipment in the first set are to be jointly admitted.

[0024] The at least one first request may relate to the provision of a multi-modal service.

[0025] The at least one first request may comprise support information for configuring for a Low Latency, Low Loss, Scalable Throughput data traffic.

[0026] According to a third aspect, there is provided an apparatus for a network exposure function, the apparatus comprising means for: receiving, from an application function, a reservation request to reserve resources for an application function session, the reservation request comprising an indication of a plurality of user equipment for which resources are to be reserved, and an indication that the plurality of user equipment are to be jointly admitted and/or their resources are to be jointly retained; determining that first policy control function is associated with a first set of user equipment of the plurality of user equipment; and signalling, to the first policy control function, at least one first request to determine a first policy in respect of resources to be reserved for the first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set.

[0027] The apparatus may comprise means for: determining that a second policy control function is associated with a second set of user equipment of the plurality of user equipment; and signalling, to the second policy control function, at least one second request to determine a second policy in respect of resources to be reserved for the second set of user equipment, the at least one second request comprising an indication of a number of user equipment comprised in the second set.

[0028] The apparatus may comprise means for: receiving, from the first and second policy control functions, respective indications that the first and second sets of user equipment were successfully jointly admitted; and signalling, to the application function, an indication that the plurality of user equipment were successfully jointly admitted.

[0029] The apparatus may comprise means for: receiving, from the first policy control function, an indication that the first set of user equipment were successfully jointly admitted; receiving, from the second policy control function, an indication that the second set of user equipment were not successfully jointly admitted; and signalling, to the application function, an indication that the plurality of user equipment were not successfully jointly admitted. [0030] The apparatus may comprise means for: signalling, to the first policy control function, an indication that the plurality of user equipment were not successfully jointly admitted.

[0031] The means for signalling the at least one first request may comprise means for: signalling a plurality of first requests for resources to be reserved, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment.

[0032] The apparatus may comprise means for: receiving, from the first policy control function, an indication that resources could not be retained in respect of at least one of the first set of user equipment; identifying all policy control functions that serve a flow group associated with the first set of user equipment; and signalling, to at least one of said all policy control functions, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment.

[0033] The apparatus may comprise means for: signalling, to the application function, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment.

[0034] The apparatus may comprise means for: subsequent to signalling said at least one of said policy control functions, receiving from said at least one of said policy control functions, an indication that resources could not be retained in respect of at least one of the plurality of user equipment served by the said at least one of said policy control functions.

[0035] The at least one first request may comprise at least one of: an identifier of at least one of the user equipment comprised in the first set; an identifier of a flow group to which the first set of user equipment are associated; and an indication that the user equipment in the first set are to be jointly admitted.

[0036] The at least one first request may relate to the provision of a multi-modality service.

[0037] The at least one first request may comprise support information for configuring for a Low Latency, Low Loss, Scalable Throughput data traffic.

[0038] According to a fourth aspect, there is provided an apparatus for a first policy control function, the apparatus comprising means for: receiving, from a network exposure interface, at least one first request to determine a first policy in respect of resources to be reserved for a first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set; and abstaining from determining said first policy until the number of at least one first requests received equals the number of user equipment comprised in the first set.

[0039] The apparatus may comprise means for: attempting to determine said first policy when the number of at least one first requests received equals the number of user equipment comprised in the first set; and when the first policy is successfully determined, signalling to the network exposure function an indication that the first set of user equipment have been successfully jointly admitted; and when the first policy is not successfully determined, signalling to the network exposure function an indication that the first set of user equipment have not been successfully jointly admitted.

[0040] The apparatus may comprise means for, when the first policy is successfully determined: providing the first policy to a session management function; receiving, from the session management function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment; and signalling, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment.

[0041] The apparatus may comprise means for, when the first policy is successfully determined: receiving, from the network exposure function, an indication that at least one user equipment associated with a same flow group as the first set of user equipment has not had resources retained in respect of it; signalling, to a session management function, an instruction to release and/or reconfigure resources for each user equipment in the first set of user equipment; and signalling, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment. [0042] The means for receiving the at least one first request may comprise means for receiving a plurality of first requests for resources to be reserved and/or retained, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment.

[0043] The at least one first request may comprise at least one of: an identifier of at least one of the user equipment comprised in the first set; an identifier of a flow group to which the first set of user equipment are associated; and an indication that the user equipment in the first set are to be jointly admitted.

[0044] The at least one first request may relate to the provision of a multi-modality service.

[0045] The at least one first request may comprise support information for configuring for a Low Latency, Low Loss, Scalable Throughput data traffic.

[0046] According to a fifth aspect, there is provided an apparatus for a network exposure function, the apparatus comprising: at least one processor; and at least one memory comprising code that, when executed by the at least one processor, causes the apparatus to: receive, from an application function, a reservation request to reserve resources for an application function session, the reservation request comprising an indication of a plurality of user equipment for which resources are to be reserved, and an indication that the plurality of user equipment are to be jointly admitted and/or their resources are to be jointly retained; determine that first policy control function is associated with a first set of user equipment of the plurality of user equipment; and signal, to the first policy control function, at least one first request to determine a first policy in respect of resources to be reserved for the first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set. [0047] The apparatus may be caused to: determine that a second policy control function is associated with a second set of user equipment of the plurality of user equipment; and signal, to the second policy control function, at least one second request to determine a second policy in respect of resources to be reserved for the second set of user equipment, the at least one second request comprising an indication of a number of user equipment comprised in the second set.

[0048] The apparatus may be caused to: receive, from the first and second policy control functions, respective indications that the first and second sets of user equipment were successfully jointly admitted; and signal, to the application function, an indication that the plurality of user equipment were successfully jointly admitted.

[0049] The apparatus may be caused to: receive, from the first policy control function, an indication that the first set of user equipment were successfully jointly admitted; receive, from the second policy control function, an indication that the second set of user equipment were not successfully jointly admitted; and signal, to the application function, an indication that the plurality of user equipment were not successfully jointly admitted.

[0050] The apparatus may be caused to: signal, to the first policy control function, an indication that the plurality of user equipment were not successfully jointly admitted.

[0051] The signalling the at least one first request may comprise: signalling a plurality of first requests for resources to be reserved, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment.

[0052] The apparatus may be caused to: receive, from the first policy control function, an indication that resources could not be retained in respect of at least one of the first set of user equipment; identify all policy control functions that serve a flow group associated with the first set of user equipment; and signal, to at least one of said all policy control functions, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment.

[0053] The apparatus may be caused to: signal, to the application function, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment.

[0054] The apparatus may be caused to: subsequent to signalling said at least one of said policy control functions, receive from said at least one of said policy control functions, an indication that resources could not be retained in respect of at least one of the plurality of user equipment served by the said at least one of said policy control functions.

[0055] The at least one first request may comprise at least one of: an identifier of at least one of the user equipment comprised in the first set; an identifier of a flow group to which the first set of user equipment are associated; and an indication that the user equipment in the first set are to be jointly admitted. [0056] The at least one first request may relate to the provision of a multi-modality service.

[0057] The at least one first request may comprise support information for configuring for a Low Latency, Low Loss, Scalable Throughput data traffic.

[0058] According to a sixth aspect, there is provided an apparatus for a first policy control function, the apparatus comprising: at least one processor; and at least one memory comprising code that, when executed by the at least one processor, causes the apparatus to: receive, from a network exposure interface, at least one first request to determine a first policy in respect of resources to be reserved for a first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set; and abstain from determining said first policy until the number of at least one first requests received equals the number of user equipment comprised in the first set.

[0059] The apparatus may be caused to: attempt to determine said first policy when the number of at least one first requests received equals the number of user equipment comprised in the first set; and when the first policy is successfully determined, signal to the network exposure function an indication that the first set of user equipment have been successfully jointly admitted; and when the first policy is not successfully determined, signal to the network exposure function an indication that the first set of user equipment have not been successfully jointly admitted.

[0060] The apparatus may be caused to: when the first policy is successfully determined: provide the first policy to a session management function; receiving, from the session management function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment; and signal, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment.

[0061] The apparatus may be caused to, when the first policy is successfully determined: receive, from the network exposure function, an indication that at least one user equipment associated with a same flow group as the first set of user equipment has not had resources retained in respect of it; signal, to a session management function, an instruction to release and/or reconfigure resources for each user equipment in the first set of user equipment; and signal, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment.

[0062] The receiving the at least one first request may comprise receiving a plurality of first requests for resources to be reserved and/or retained, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment.

[0063] The at least one first request may comprise at least one of: an identifier of at least one of the user equipment comprised in the first set; an identifier of a flow group to which the first set of user equipment are associated; and an indication that the user equipment in the first set are to be jointly admitted. [0064] The at least one first request may relate to the provision of a multi-modality service.

[0065] The at least one first request may comprise support information for configuring for a Low Latency, Low Loss, Scalable Throughput data traffic.

[0066] According to a seventh aspect, there is provided an apparatus for a network exposure function, the apparatus comprising: receiving circuitry for receiving, from an application function, a reservation request to reserve resources for an application function session, the reservation request comprising an indication of a plurality of user equipment for which resources are to be reserved, and an indication that the plurality of user equipment are to be jointly admitted and/or their resources are to be jointly retained; determining circuitry for determining that first policy control function is associated with a first set of user equipment of the plurality of user equipment; and signalling circuitry for signalling, to the first policy control function, at least one first request to determine a first policy in respect of resources to be reserved for the first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set.

[0067] The apparatus may comprise: determining circuitry for determining that a second policy control function is associated with a second set of user equipment of the plurality of user equipment; and signalling circuitry for signalling, to the second policy control function, at least one second request to determine a second policy in respect of resources to be reserved for the second set of user equipment, the at least one second request comprising an indication of a number of user equipment comprised in the second set.

[0068] The apparatus may comprise: receiving circuitry for receiving, from the first and second policy control functions, respective indications that the first and second sets of user equipment were successfully jointly admitted; and signalling circuitry for signalling, to the application function, an indication that the plurality of user equipment were successfully jointly admitted.

[0069] The apparatus may comprise: receiving circuitry for receiving, from the first policy control function, an indication that the first set of user equipment were successfully jointly admitted; receiving circuitry for receiving, from the second policy control function, an indication that the second set of user equipment were not successfully jointly admitted; and signalling circuitry for signalling, to the application function, an indication that the plurality of user equipment were not successfully jointly admitted.

[0070] The apparatus may comprise: signalling circuitry for signalling, to the first policy control function, an indication that the plurality of user equipment were not successfully jointly admitted.

[0071] The signalling circuitry for signalling the at least one first request may comprise: signalling circuitry for signalling a plurality of first requests for resources to be reserved, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment. [0072] The apparatus may comprise: receiving circuitry for receiving, from the first policy control function, an indication that resources could not be retained in respect of at least one of the first set of user equipment; identifying all policy control functions that serve a flow group associated with the first set of user equipment; and signalling circuitry for signalling, to at least one of said all policy control functions, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment.

[0073] The apparatus may comprise: signalling circuitry for signalling, to the application function, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment.

[0074] The apparatus may comprise: receiving circuitry for subsequent to signalling said at least one of said policy control functions, receiving from said at least one of said policy control functions, an indication that resources could not be retained in respect of at least one of the plurality of user equipment served by the said at least one of said policy control functions.

[0075] The at least one first request may comprise at least one of: an identifier of at least one of the user equipment comprised in the first set; an identifier of a flow group to which the first set of user equipment are associated; and an indication that the user equipment in the first set are to be jointly admitted.

[0076] The at least one first request may relate to the provision of a multi-modality service.

[0077] The at least one first request may comprise support information for configuring for a Low Latency, Low Loss, Scalable Throughput data traffic.

[0078] According to an eighth aspect, there is provided an apparatus for a first policy control function, the apparatus comprising: receiving circuitry for receiving, from a network exposure interface, at least one first request to determine a first policy in respect of resources to be reserved for a first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set; and abstaining circuitry for abstaining from determining said first policy until the number of at least one first requests received equals the number of user equipment comprised in the first set.

[0079] The apparatus may comprise: attempting circuitry for attempting to determine said first policy when the number of at least one first requests received equals the number of user equipment comprised in the first set; and signalling circuitry for when the first policy is successfully determined, signalling to the network exposure function an indication that the first set of user equipment have been successfully jointly admitted; and signalling circuitry for, when the first policy is not successfully determined, signalling to the network exposure function an indication that the first set of user equipment have not been successfully jointly admitted.

[0080] The apparatus may comprise, when the first policy is successfully determined: providing circuitry for providing the first policy to a session management function; receiving, from the session management function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment; and signalling circuitry for signalling, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment. [0081] The apparatus may comprise, when the first policy is successfully determined: receiving circuitry for receiving, from the network exposure function, an indication that at least one user equipment associated with a same flow group as the first set of user equipment has not had resources retained in respect of it; signalling circuitry for signalling, to a session management function, an instruction to release and/or reconfigure resources for each user equipment in the first set of user equipment; and signalling circuitry for signalling, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment.

[0082] The receiving circuitry for receiving the at least one first request may comprise receiving circuitry for receiving a plurality of first requests for resources to be reserved and/or retained, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment.

[0083] The at least one first request may comprise at least one of: an identifier of at least one of the user equipment comprised in the first set; an identifier of a flow group to which the first set of user equipment are associated; and an indication that the user equipment in the first set are to be jointly admitted.

[0084] The at least one first request may relate to the provision of a multi-modalilty service.

[0085] The at least one first request may comprise support information for configuring for a Low Latency, Low Loss, Scalable Throughput data traffic.

[0086] According to a ninth aspect, there is provided non-transitory computer readable medium comprising program instructions for causing an apparatus for a network exposure function to perform at least the following: receive, from an application function, a reservation request to reserve resources for an application function session, the reservation request comprising an indication of a plurality of user equipment for which resources are to be reserved, and an indication that the plurality of user equipment are to be jointly admitted and/or their resources are to be jointly retained; determine that first policy control function is associated with a first set of user equipment of the plurality of user equipment; and signal, to the first policy control function, at least one first request to determine a first policy in respect of resources to be reserved for the first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set.

[0087] The apparatus may be caused to: determine that a second policy control function is associated with a second set of user equipment of the plurality of user equipment; and signal, to the second policy control function, at least one second request to determine a second policy in respect of resources to be reserved for the second set of user equipment, the at least one second request comprising an indication of a number of user equipment comprised in the second set.

[0088] The apparatus may be caused to: receive, from the first and second policy control functions, respective indications that the first and second sets of user equipment were successfully jointly admitted; and signal, to the application function, an indication that the plurality of user equipment were successfully jointly admitted.

[0089] The apparatus may be caused to: receive, from the first policy control function, an indication that the first set of user equipment were successfully jointly admitted; receive, from the second policy control function, an indication that the second set of user equipment were not successfully jointly admitted; and signal, to the application function, an indication that the plurality of user equipment were not successfully jointly admitted.

[0090] The apparatus may be caused to: signal, to the first policy control function, an indication that the plurality of user equipment were not successfully jointly admitted.

[0091] The signalling the at least one first request may comprise: signalling a plurality of first requests for resources to be reserved, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment.

[0092] The apparatus may be caused to: receive, from the first policy control function, an indication that resources could not be retained in respect of at least one of the first set of user equipment; identify all policy control functions that serve a flow group associated with the first set of user equipment; and signal, to at least one of said all policy control functions, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment.

[0093] The apparatus may be caused to: signal, to the application function, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment.

[0094] The apparatus may be caused to: subsequent to signalling said at least one of said policy control functions, receive from said at least one of said policy control functions, an indication that resources could not be retained in respect of at least one of the plurality of user equipment served by the said at least one of said policy control functions.

[0095] The at least one first request may comprise at least one of: an identifier of at least one of the user equipment comprised in the first set; an identifier of a flow group to which the first set of user equipment are associated; and an indication that the user equipment in the first set are to be jointly admitted.

[0096] The at least one first request may relate to the provision of a multi-modality service.

[0097] The at least one first request may comprise support information for configuring for a Low Latency, Low Loss, Scalable Throughput data traffic. [0098] According to a tenth aspect, there is provided non-transitory computer readable medium comprising program instructions for causing an apparatus for a first policy control function to perform at least the following: receive, from a network exposure interface, at least one first request to determine a first policy in respect of resources to be reserved for a first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set; and abstain from determining said first policy until the number of at least one first requests received equals the number of user equipment comprised in the first set.

[0099] The apparatus may be caused to: attempt to determine said first policy when the number of at least one first requests received equals the number of user equipment comprised in the first set; and when the first policy is successfully determined, signal to the network exposure function an indication that the first set of user equipment have been successfully jointly admitted; and when the first policy is not successfully determined, signal to the network exposure function an indication that the first set of user equipment have not been successfully jointly admitted.

[0100] The apparatus may be caused to: when the first policy is successfully determined: provide the first policy to a session management function; receiving, from the session management function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment; and signal, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment.

[0101] The apparatus may be caused to, when the first policy is successfully determined: receive, from the network exposure function, an indication that at least one user equipment associated with a same flow group as the first set of user equipment has not had resources retained in respect of it; signal, to a session management function, an instruction to release and/or reconfigure resources for each user equipment in the first set of user equipment; and signal, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment.

[0102] The receiving the at least one first request may comprise receiving a plurality of first requests for resources to be reserved and/or retained, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment.

[0103] The at least one first request may comprise at least one of: an identifier of at least one of the user equipment comprised in the first set; an identifier of a flow group to which the first set of user equipment are associated; and an indication that the user equipment in the first set are to be jointly admitted.

[0104] The at least one first request may relate to the provision of a multi-modality service.

[0105] The at least one first request may comprise support information for configuring for a Low Latency, Low Loss, Scalable Throughput data traffic. [0106] According to an eleventh aspect, there is provided a computer program product stored on a medium that may cause an apparatus to perform any method as described herein.

[0107] According to a twelfth aspect, there is provided an electronic device that may comprise apparatus as described herein.

[0108] According to a thirteenth aspect, there is provided a chipset that may comprise an apparatus as described herein.

Brief description of Figures

[0109] Some examples, will now be described, merely by way of illustration only, with reference to the accompanying drawings in which:

[0110] Figures 1A and IB show a schematic representation of a 5G system;

[0111] Figure 2 shows a schematic representation of a network apparatus;

[0112] Figure 3 shows a schematic representation of a user equipment;

[0113] Figure 4 shows a schematic representation of a non-volatile memory medium storing instructions which when executed by a processor allow a processor to perform one or more of the steps of the methods of some examples;

[0114] Figure 5 shows a schematic representation of a network;

[0115] Figures 6 to 8 illustrate example signalling;

[0116] Figures 9A to 9C illustrate example signalling; and

[0117] Figures 10 and 11 illustrate example signalling that may be performed by apparatus described herein.

Detailed description

[0118] In the following description of examples, certain aspects are explained with reference to mobile communication devices capable of communication via a wireless cellular system and mobile communication systems serving such mobile communication devices. For brevity and clarity, the following describes such aspects with reference to a 5G wireless communication system. However, it is understood that such aspects are not limited to 5G wireless communication systems, and may, for example, be applied to other wireless communication systems (for example, current 6G proposals).

[0119] Before describing in detail the examples, certain general principles of a 5G wireless communication system are briefly explained with reference to Figures 1A and IB.

[0120] Figure 1A shows a schematic representation of a 5G system (5GS) 100. The 5GS may comprise a user equipment (UE) 102 (which may also be referred to as a communication device or a terminal), a 5G access network (AN) (which may be a 5G Radio Access Network (RAN) or any other type of 5G AN such as an AN comprising a Non-3GPP Interworking Function (N3IWF) and a Trusted Non3GPP Gateway Function (TNGF) for Untrusted / Trusted Non-3GPP access or an AN comprising a Wireline Access Gateway Function (W-AGF) for Wireline access) 104, a 5G core (5GC) 106, one or more application functions (AF) 108 and one or more data networks (DN) 110.

[0121] The 5G RAN may comprise one or more gNodeB (gNB) distributed unit functions connected to one or more gNodeB (gNB) unit functions. The RAN may comprise one or more access nodes.

[0122] The 5GC 106 may comprise one or more Access and Mobility Management Functions (AMF) 112, one or more Session Management Functions (SMF) 114, one or more authentication server functions (AUSF) 116, one or more unified data management (UDM) functions 118, one or more user plane functions (UPF) 120, one or more unified data repository (UDR) functions 122, one or more network repository functions (NRF) 128, and/or one or more network exposure functions (NEF) 124. The role of an NEF is to provide secure exposure of network services (e.g., voice, data connectivity, charging, subscriber data, and so forth) to other network functions of the 5GC and network functions of 3rd parties. Although NRF 128 is not depicted with its interfaces, it is understood that this is for clarity reasons and that NRF 128 may have a plurality of interfaces with other network functions.

[0123] The 5GC 106 also comprises a network data analytics function (NWDAF) 126. The NWDAF is responsible for providing network analytics information upon request from one or more network functions or apparatus within the network. Network functions can also subscribe to the NWDAF 126 to receive information therefrom. Accordingly, the NWDAF 126 is also configured to receive and store network information from one or more network functions or apparatus within the network. The data collection by the NWDAF 126 may be performed based on at least one subscription to the events provided by the at least one network function.

[0124] Figure IB shows a schematic representation of a service-based architecture of a 5GC represented in 3GPP TS 23.501. It is understood that this schematic representation is intended to illustrate potential network functions that may be comprised in a core network, and the presently described principles are not limited to core networks comprising only the described network functions.

[0125] Figure IB shows a 5GC 106’ comprising a UPF 120’ connected to an SMF 114’ over an N4 interface. The SMF 114’ is connected to each of a UDM 122’, an NEF 124’, an NWDAF 126’, an AF 108’, a Policy Control Function (PCF) 130’, an AMF 112’, and a Charging function 132’ over an interconnect medium that also connects these network functions to each other. The 5GC 106’ further comprises a network repository function (NRF) 133’ and a network function 134’ that connect to the interconnect medium. [0126] 3GPP refers to a group of organizations that develop and release different standardized communication protocols. 3GPP develops and publishes documents pertaining to a system of “Releases” (e.g., Release 15, Release 16, and beyond).

[0127] To manage data traffic for a UE using multiple access concurrently, an operator can define policies to flexibly use multiple access for different data flows.

[0128] For 3GPP Release 18, 5G System (5GS) enhancements to support extended reality (XR) and media services are being considered (see, for example, 3GPP (TR 23.700-60)).

[0129] At least one of the studies being performed for of Release 18 XR and media service relates to supporting application synchronization (e.g., so that service users of media services have synchronised playout of data) and Quality of Service (QoS) policy coordination for multi-modal traffic among multiple UEs.

[0130] There are several objectives associated with this study. For example, one objective relates to whether (and how) to enable, for multiple UEs, delivering application-related tactile and multi-modal data (e.g., audio, video and haptic data related to a specific time) with the application to a user at a similar time, focusing on the need for policy control enhancements (e.g., QoS policy coordination).

[0131] Another objective relates to potential enhancements to policy control to support coordination handling at the application.

[0132] Another objective relates to whether (and how) any interaction is to be performed between an AF and the 5GS for QoS policy coordination among multiple UEs.

[0133] Most of the solutions proposed in 3GPP standardization aim to solve is how a 5G System (5GS) can perform joint admission control and (enforcement of) joint QoS requirement fulfilment for a group of traffic flows for one or more UEs. In particular, a request for the joint QoS is made by an Application Function, which enumerates the traffic flows and their requirements and provides a policy for joint admission and joint QoS fulfilment (a so-called “joint policy”). As used herein, joint admission control may refer to the 5GS admitting all the traffic flows in the group or none of them. Further as used herein, joint QoS fulfilment may refer to QoS requirements being fulfilled for all the traffic flows in the group or none of them. The traffic flows may be related to multiple UEs, and there may be multiple PCFs involved. For example, each UE receiving jointly admitted flows may be served by a separate PCF.

[0134] To address at least one of these issues, joint admission may be limited to use a same PCF in creation of a Protocol Data Unit (PDU) session, and/or establishment of a multi-modal communication may use the overhead of communication in a binding support function (BSF) in the 5GC, and/or the network may predefine groups of UEs that may be jointly admitted based on a configuration of those UEs in a UDM or UDR.

[0135] These examples are illustrated with respect to Figures 6 to 8. [0136] Figure 6 illustrates signalling that may be between various network functions (otherwise referred to as network entities) of a 5GC for dynamically coordinating across multiple PCFs using a group policy that is predefined at an application for a group of UEs. Figure 6 illustrates that when a PCF receives policy requirements of multiple UEs from multiple sources (for example, from both an application and from other PCFs), either at the same time or within a predetermined time duration of each other, the PCF may determine a group policy that fulfils the multiple requirements.

[0137] As can be seen in Figure 6, this results in application functions (e.g., AF1, AF2) provisioning group policies at an application level, and requesting policies for session establishment from respective PCFs. The respective PCFs are then configured to exchange a policy determined in dependence on their received policy request in order that they may modify their determined policy so that it is consistent with for the multiple UEs. In other words, in the example of Figure 6, PCFs exchange information for coordinating the policies they provide in respect of a multi-modality service.

[0138] Figure 7 illustrates example signalling between various network functions of a 5CG when a same PCF is selected for multiple UE for providing a multi-modality service. In the example shown in Figure 7, a binding support function of the 5GC is maintaining a PCF register. The SMF may query the binding support function whether the binding support function already has an existing PCF serving a combination of Subscriber Permanent Identifier (SUPI), slice identifier (e.g., single- network slice selection assistance information), data network name, and internal group identifier. When the binding support function sends a response to the query which indicates that there is such an existing PCF, this existing PCF may be used for additional UEs subscribing to receive the multi-modality service. When the binding support function sends a response to the query which indicates that there is not such an existing PCF, a new PCF may be selected by the SMF for policy establishment.

[0139] Figure 8 illustrates an example in which there is QoS policy coordination for multiple UEs’ Quality of Service (QoS) flows by using the binding support function (BSF) as a coordinating network function. In ethe example illustrated in Figure 8, PCFs signal the BSF after generating their policy charging control rules. The PCFs register themselves at the BSF, and perform discovery and subscription procedures to discover (and receive updates from) other PCFs related to providing the multi-modality service. The PCFs may subsequently update their policies while coordinating with each other. A limitation of using the binding support function (BSF) as a coordinating network function for QoS policy coordination for multiple UEs’ Quality of Service (QoS) flows is that it involves a lot of signalling is sent between various network functions.

[0140] The following aims to address at least one of the above-mentioned objectives.

[0141] Throughout the following, reference will be made to a “multimodality” and “multimodal”. These terms may generally be considered to indicate the presence of multiple types of communication within a single medium. For example, a text message may comprise text (written words) and graphical features (e.g., pictures and emojis). Similarly, in the present context, the terms “multimodality” and “multimodal” may refer to multiple data types associated with a single application (for example, visual data, audio data, haptic data, etc.). Each data type or data type instance may be carried over the network within a separate traffic flow for the multi-modality service. Therefore, in general, a multi-modality service (or multi-modal session) may be considered as comprising multiple traffic flows (otherwise referred to service flows) that are all associated with a common flow group policy.

[0142] Further, it is understood that multi-modal data may be considered as input data from different kinds of devices/sensors, and/or as output data to different kinds of destinations for the same task or application (e.g., when data is being provided to one or more UEs). Multi-modal data may comprise more than one single-modal data, and there is strong dependency among each single-modal data. Single-modal data may be considered as a single (i.e., only one) type of data.

[0143] The following proposes that, for multimodal services with multiple UE(s) from an AF, a network exposure function (NEF) may co-ordinate a particular multi-modal session across multiple PCFs. Individual PCFs have no need to co-ordinate with each other directly.

[0144] In particular, the following relates to an NEF that, when requesting, via a PCF request, that a PCF determines a group policy in respect of a plurality of UE, identifies the number of UEs in that plurality, and identifies a UE in that plurality of UEs. The PCF request may identify a single (i.e., only one) UE in the plurality of UEs. The PCF request may further indicate that this PCF request relates to the establishment of a group policy to be applied in respect of the plurality of UEs. In other words, this PCF request may relate to requesting a joint admittance of the plurality of UEs.

[0145] The PCF may then wait until it has received analogous policy requests from the NEF in respect of every UE in the plurality of UEs before determining the requested policy. In other words, the PCF may abstain from establishing a group policy in respect of the plurality of UEs until policy requests have been received in respect of every UE in the plurality of UEs.

[0146] The NEF may also forward information related to this multi-modal session to the PCFs associated with UEs in the group. The forwarded information may comprise, for example, information related to failure of joint-QoS fulfilment for UEs in the group when resources cannot be reserved and/or configured by a Radio Access Network (RAN), and/or joint admission control failure for one or more service flows or out of synchronization issues.

[0147] The presently described embodiments enable a PCF to remain as the decision maker for determining policies for the service flows within the group and to maintain the same policy for multi-modal sessions across multiple PCFs. In particular, the NEF may be mainly used for forwarding messages across PCFs associated with a jointly admitted/handled group of UEs to facilitate coordination therebetween. [0148] Further, when multiple PDU sessions for a single UE are managed by multiple PCFs, the NEF may co-ordinate across the multiple PCFs.

[0149] The NEF may use a group identifier (herein labelled as a “flow co-ordination group-ID”) to aggregate multi-modal sessions.Jn other words, the NEF may use a group identifier to group together a set of UEs and a set of PCFs that are associated with a same multi-modal session. This aggregation supports NEF to identify the related PCF in the multi-modal session during any failure.

[0150] The RAN may perform consistent marking of Explicit Congestion Notification (ECN) for the purpose of Eow Eatency, Eow Foss, Scalable Throughput (E4S) across all service flows in the flow group to ensure that the data rate adaptation request is also synchronized. For example, when a RAN entity marks 10% of packets for service flow 1, then the RAN entity may do the same for all service flows in the group. The AF may also request for consistent data rate across all service flows in the flow group. ECN is currently defined in draft-ietf-tsvwg-ecn-14s-id-27, “Explicit Congestion Notification (ECN) Protocol for Very Low Queuing Delay (L4S).

[0151] These concepts are illustrated further with reference to the example of Figures 9A to 9C.

[0152] Figures 9 A to 9C illustrates signalling between a first UE 901, a second UE 902, a third UE 903, a first SMF 904, a second SMF 905, a first PCF 906, a second PCF 907, an NEF 908 and an application function 909. The signalling shown in these examples may illustrate multiple PCF handling with joint admission failure. In the present example, the first and third UEs 901, 903 are assumed to share a common PCF (e.g., the first PCF 906), and the second UE is assumed to receive policies from another PCF (e.g., the second PCF 907).

[0153] In this example of Figures 9A to 9C, the NEF discovers multiple PCFs related to, other otherwise associated with, the multiple UEs that are grouped for joint handling and/or joint admission, and performs authorization. The NEF may co-ordinate operations across the multiple PCFs using a flow co-ordination group-ID. In case of any failure in one of the service flows associated with this group of service flows, the NEF may signal (i.e., send) an indication of this failure to the PCFs in this group of service flows.

[0154] During 9001, respective PDU sessions are established for each UE.

[0155] At 9002, the AF 909 signals the NEF 908. The AF 909 may signal the NEF 908 at 9002 by sending a request to create an application function session with a predetermined QoS. In other words, the AF 909 may send a request to the NEF 909 to reserve resources in respect of at least one PDU session that has been established. The signal (e.g., the request) sent by the AF 909 at 9002 may comprise an Nnef_AFsessionWithQoS_Update request message service operation. The signal (e.g., the request) sent at 9002 may identify a group of service flows related to multiple UEs. The group of service flows may indicate those service flows that are intended to be played out simultaneously, such as a service flow for audio data, a service flow for visual data, a service flow for haptic data, etc. [0156] For example, at least one of the following information may be comprised in the signal (e.g., the request) sent at 9002: identification of UEs that are to be jointly handled/admitted (for example, an identification of the first UE 901, an identification of the second UE 902, and an identification of the third UE 903); related to each UE in the group of service flows, a set of service flow descriptions and their QoS requirements; flow group QoS policies (i.e. QoS policies for the service flow group) that are to be applied across the service flows; an indication that joint-admission is to be performed for the identified UEs and/or flows; and indication that joint-fulfilment is to be performed for the identified UEs and/or flow; or an indication that communications to be delivered to the identified UEs and/or flow are to be delivered in sync. It is understood that, in some examples, not all of the presently mentioned information may be comprised in the signal (e.g., the request) sent at 9002, while in other examples, all of the presently mentioned information may be comprised in the signal (e.g., the request) sent at 9002.

[0157] The signal (e.g., the request) sent at9002 may comprise an identifier for this group of UEs and/or service flows (labelled herein as a Flow-group-id). The signal (e.g., the request) sent at 9002 may comprise information that indicates whether an L4S congestion avoidance mechanism is to be supported for the given AF’s service flows in the 5GS (or is not to be supported).

[0158] During 9003, the NEF 908 authorizes the request received from the AF 909 at 9002, and discovers those PCFs related to each of the UEs included in the request received from AF 909. The authorization of request received from the AF 909 and the discover those PCFs related to each of the UEs included in the request received from AF 909 is as described in 3GPP TS 23.502 (see, for example Section 4.15.6.6 (step 3) of 3GPP TS 23.502). For example, the NEF 908 may discover the related PCFs by querying a binding support function for this information. In the present example, the NEF may discover the first PCF 906 is associated with the first and third UEs, and the second PCF 907 is associated with the second UE 902.

[0159] Based on the discovery, the NEF may determine how many separate requests are to be sent to each PCF for authorizing a policy that covers the whole group of service flows (flow group). These requests are labelled as Npcf_PolicyAuthorization_Create requests herein. In practice, the number of separate requests to be sent to each PCF may correspond to the number of different UEs for the group served by each PCF.

[0160] At 9004, the NEF 908 signals the first PCF 906. The NEF may signal the first PCF 906 at 9004 by sending a request for policy authorization in respect of the first UE 901. For example, of the signal (e.g., the request sent by the NEF 908) at 9004 may comprise anNpcf_PolicyAuthorization_create request. The signal (e.g., the request sent by the NEF 908) at 9004 may comprise information for identifying the first UE 901, in addition to information related to the flow group and/or QoS properties to which the policy will belong. For example, the signal (e.g., the request sent by the NEF 908) at 9004 may comprise at least one of: an address for the first UE 901, an identifier of the first UE 901, an identification of the flow-group-ID, an identification of the flow group’s QoS policies, a total number of requests for this PCF to cover the whole flow-group (which, in the present example, is two, as the first PCF is serving both the first and third UEs), QoS requirements, or any policies for the flow group policies (such as, for example, the above- mentioned joint-admission, joint-QoS fulfilment, and/or L4S support information). The QoS requirements may comprise QoS parameters that characterize (or otherwise define) the QoS to be met by the policies for the flow group. In addition, the QoS requirements may comprise a QoS reference. In addition, where applicable, the QoS requirements may comprise alternative service requirements for a given UE to which the QoS requirements are to be applied.

[0161] The first PCF 906 may use the received number of requests for the group of service flows to determine when the first PCF has received all requests related to the group of service flow, and can proceed with signalling an associated SMF with full information relating to all of the service flows/UEs in the group of service flows that are served by the first PCF 906. This is discussed later in relation to the PCFs signalling SMFs in Figures 9A-9C.

[0162] At 9005, the first PCF 906 performs session binding. However, as the first PCF 906 can determine from the received signals that the PCF 906 expects to receive two requests for this flow group, but the first PCF 906 knows that it has only received one request, the PCF abstains from signalling an SMF in respect of this flow group until the remaining messages/requests have been received.

[0163] At 9006, the NEF 908 signals the second PCF 907. The NEF 908 may signal the second PCF 907 at 9006 by sending a request for policy authorization in respect of the second UE 902. For example, this signal (e.g., the request sent by the NEF 908) at 9006 may comprise an Npcf_PolicyAuthorization_create request. The signal (e.g., the request sent at 9006 may comprise information for identifying the second UE 902, in addition to information related to the flow group and/or QoS properties to which the policy will belong. For example, the signal (e.g., the request sent at 9006) may comprise at least one of: an address for the second UE 902, an identifier of the second UE 902, an identification of the flow-group-ID, an identification of the flow group’s QoS policies, a total number of requests for this PCF to cover the whole flow-group (which, in the present example, is one, as the second PCF is serving only the second UE), QoS requirements, or any policies for the flow group policies (such as, for example, the above-mentioned jointadmission, joint-QoS fulfilment, and/or E4S support information).

[0164] The second PCF 907 may use the received number of requests for the group to determine when the second PCF has received all requests related to the group, and can proceed with signalling an associated SMF with full information relating to all of the service flows/UEs in the group that are served by the second PCF 907. This is discussed later in relation to the PCFs signalling SMFs in Figures 9A-9C.

[0165] During 9007, the second PCF 907 performs session binding. As the second PCF 907 can determine from the received signalling that the second PCF 907 expects to receive one requests for this flow group, and the second PCF 907 knows that it has only received one request, the second PCF 907 may proceed with signalling an SMF in respect of this flow group.

[0166] For example, for the given flow group-ID, the second PCF 907 can proceed immediately with the creation of group policy across multiple PDU sessions for the second UE 902, and may signal during 9008, to an SMF, information in respect of this group flow. For example, the second PCF 907 may signal during 9008, to the SMF, information in respect of at least one of: flow-group IDs/policies associated with the flow group, QoS requirements, or flow group policies in respect of at least one of: joint-admission, joint- QoS fulfilment; or L4S support information. This information to the SMF may correspond to the information received by the second PCF 907 during 9006.

[0167] At 9009, the NEF 908 signals the first PCF 906. The NEF 908 may signal the first PCF 906 at 9009 by sending a request for policy authorization in respect of the third UE 903. For example, the signal (e.g., the request sent by the NEF 908) at 9009 may comprise anNpcf_PolicyAuthorization_create request. The signal (e.g., the request sent by the NEF 908) at 9009 may comprise information for identifying the third UE 903, in addition to information related to the flow group and/or QoS properties to which the policy will belong. For example, the signalling of 9008 may comprise at least one of: an address for the third UE 903, an identifier of the third UE 903, an identification of the flow-group-ID, an identification of the flow group’s QoS policies, a total number of requests for this PCF to cover the whole flow-group (which, in the present example, is two, as the first PCF is serving both the first and third UEs), QoS requirements, or any policies for the flow group policies (such as, for example, the above-mentioned joint-admission, joint-QoS fulfilment, and/or L4S support information).

[0168] The first PCF 906 may use the received number of requests for the group to determine when the first PCF has received all requests related to the group, and can proceed with signalling an associated SMF with full information relating to all of the service flows/UEs in the group that are served by the first PCF 906. This is discussed later in relation to the PCFs signalling SMFs in Figures 9A-9C.

[0169] During 9010, the first PCF 906 performs session binding. As the first PCF 906 can determine from the received signalling that the PCF 906 expects to receive two requests for this flow group, and the first PCF 906 knows that it has received two request, the PCF proceeds with signalling an SMF in respect of this flow group as all of the remaining messages/requests have been received.

[0170] During 9011, the first PCF 906 determines that the first PCF 906 has received all of the requests that it expects to receive in respect of this Flow-group ID, and proceeds with creating a group policy for multiple PDU that are related to the flows associated with the first and third UEs.

[0171] After the group policy has been established, the first PCF 906 communicates with an SMF in respect of the flows of the first and third UEs. This signalling of the first PCF 906 with an SMF may provide the SMF with information in respect of at least one of: flow-group ID/policies, QoS requirements, or policies for the group flow, which may comprise at least one of: joint-admission, joint-QoS fulfilment, or L4S support information).

[0172] Figure 9B illustrates signalling between the same entities as depicted in Figure 9A, and so the same notation will be employed.

[0173] Figure 9B illustrates two separate cases: 9012 to 9015 relate to the case when there has been successful joint admission of all of the UE associated with the group flow, while 9016 to 9020 relate to the case when there has not been successful join admission of all of the UE associated with the group flow. Therefore, in Figure 9A, the first PCF 906 may send a signal at 9012 or 9016, depending on whether the joint admission has been successful.

[0174] At 9012, the first PCF 906 signals the NEF 908. The first PCF 906 may signal the NEF 908 by sending a request to the NEF 908. The signal (or the message sent by first PCF 906) at 9012 may comprise an indication that joint admission for the flow group having the flow group-ID has been successful for the flows in the flow group associated with the first and third UEs.

[0175] At 9013, the second PCF 907 signals the NEF 908. The second PCF 908 may signal the NEF 908 by sending a message to the NEF 908. of the signal (or the message sent by the second PCF 907) at 9013 may comprise an indication that joint admission for the flow group having the flow group-ID has been successful for the flows in the flow group associated with the second UE 902.

[0176] During 9014, the NEF determines that the NEF 908 has received admission results in respect of all of the UEs in the flow group, and that the overall result is indicated as being successful.

[0177] At 9015, the NEF 908 signals the AF 909. The NEF 908 may signal the AF 909 by sending a message to the AF 909. The signal (or the message sent by the NEF 908) at 9015 may indicate that joint admission has successfully been performed in respect of all of the UEs in the flow group. After receiving, and in response to, signal (or message), the application function may proceed with sending data traffic to the UEs. For example, the application may proceed with sending multi-modal data traffic to the UEs.

[0178] As mentioned above, 9016 to 9020 relate to the example cases in which not all of the UEs in the flow group were successfully admitted.

[0179] At 9016, the first PCF 906 signals the NEF 908. The first PCF 906 may signal the NEF 908 by sending a message to the NEF 908. of the signal (or the message sent by the first PCF 906) at 9016 may comprise an indication that joint admission for the flow group having the flow group-ID has been successful for the flows in the flow group associated with the first and third UEs.

[0180] At 9017, the second PCF 907 signals the NEF 908. The second PCF 907 may signal the NEF 908 by sending a message to the NEF 908. The signal (or the message sent by the second PCF 907) at 9017 may comprise an indication that joint admission for the flow group having the flow group-ID has not been successful for the flows in the flow group associated with the second UE 902. [0181] During 9018, the NEF 908 determines that the NEF 908 has received admission results in respect of all of the UEs in the flow group, and that the overall result is indicated as not being successful in respect of the second UE 902.

[0182] At 9019, the NEF 908 signals the first PCF 906. The NEF 908 may signal the first PCF 906 by sending a message to the first PCF 906. The signal inform the first PCF 906 that the joint admission has been unsuccessful. In embodiments the NEF 908 signals the first PCF 906 by sending a message to the first PCF 906, the message may include an indication that the joint admission has been unsuccessful. Where there are more than two PCFs being considered, the NEF may inform any PCF reporting a successful result that joint admission has been unsuccessful. The NEF 908 does not inform any PCF reporting an unsuccessful result that joint admission has been unsuccessful. This is because such a reporting PCF is aware of this information, and such signalling would consequently be redundant.

[0183] In response to the signal (or the message sent) at 9019, the PCF 906 may release any resource(s) resource planned for the first and third UEs 901, 903 with respect to the joint admission of 9016. If specified in the policy/policies, the first SMF 904 and a RAN node (e.g., base station which is not shown) will be informed about this failure. This scenario is specific to joint admission scenario, and does not apply to individual admission.

[0184] At 9020, the NEF 908 signals the AF 909. The NEF 908 may signal the AF 909 by sending a message to the AF 909. The signal inform the AF 909 that the joint admission has been unsuccessful. In response to this signalling that the joint admission has been unsuccessful, the AF 909 may terminate the application function session (e.g., terminate a multi-modality session). In embodiments the NEF 908 signals the AF 909 by sending a message to the AF 909, the message may include an indication that that the joint admission has been unsuccessful. The AF 909 may terminate the application function session (e.g., terminate a multi-modality sessionjbecause the AF 909 is unable to guarantee a minimum quality of experience for all of the UEs attempting to join the application function session.

[0185] Figure 9C shows to signalling between various network functions of a 5GC and an operation that may be performed by a NEF 908 of the 5GC in the event that QoS fulfillment has failed in respect of at least part of the UEs comprised in the flow group. The QoS fulfillment may be considered to have failed when insufficient resources and/or radio bearers (according to the policy/policies defined by the PCF(s)) have been allocated to at least one of the UEs in the flow group by a RAN node (e.g., base station) responsible for performing admission control between the at least one UE and a 5GC. The signalling may be as described above in relation to any of Figures 9 A and 9B, and so the same notation will be described below. The signalling may occur following the signalling of Figure 9A, and/or after the signalling of 9015. [0186] In Figure 9C, a RAN node (e.g., a base station such as a gNB) of the RAN connecting the second UE 902 to a 5GC comprising at least the first and second SMFs 904, 905, the first and second PCFs 906, 907, and the NEF 908, signals the second SMF 905. The RAN node may be responsible for performing admission procedures for admitting a UE access to the 5CG for receiving a multi-modality service. The signal sent by the RAN node may inform the second SMF 905 that a joint QoS fulfillment policy failure has occurred in the RAN for the second UE 902. In the present context, the joint QoS fulfillment policy failure may relate to the inability of the RAN node to reserve resources (e.g., radio bearers) for fulfilling QoS requirements associated with the flow group.

[0187] At 9021, the second SMF 905 signals the second PCF 907. The second SMF 905 may signal the second PCF 907 by sending a message to the second PCF 907. The signal at 9021 may indicate to the second PCF 907 that the joint QoS fulfillment policy has failed in respect of the second UE (and/or any other UEs comprised in that flow group that are associated with the second PCF). In embodiments the second SMF 905 signals the second PCF 907 by sending a message to the second PCF 907, the message may include an indication that the joint QoS fulfillment policy has failed in respect of the second UE.

[0188] In response to this signalling at 9021, the second PCF 907 may release all service flows related to that flow group ID.

[0189] At 9022, the second PCF 907 signals the NEF 908. The second PCF 907 may signal the NEF 908 by sending a message to the NEF 908. The signal at 9023 may indicate to the NEF 908 that the joint QoS fulfillment policy has failed in respect of the second UE (and/or any other UEs comprised in that flow group that are associated with the second PCF). The signal may comprise an identifier of the flow group id. In embodiments the second PCF signals the NEF 908 by sending a message to the NEF, the message may include an indication that that the joint QoS fulfillment policy has failed in respect of the second UE.

[0190] In response to of the signal at 9022, during 9023, the NEF 908 identifies the corresponding flow group id and the related PCFs for which the joint failure information has to be passed. The related PCFs are the PCFs that are associated with other UEs comprised in this flow group. In the present case, the related PCFs comprises the first PCF.

[0191] At 9024, the NEF 908 signals the first PCF 906. The NEF 908 may signal the first PCF 906 by sending a message to the first PCF 906. The signal at 9024 may indicate to the first PCF that there has been a joint QoS fulfillment failure in respect of the flow group id. The signal may comprise an identifier of the flow group id. In embodiments the NEF 908 signals the first PCF 906 by sending a message to the first PCF 906, the message may include an indication that there has been a joint QoS fulfillment failure in respect of the flow group id.

[0192] At 9025, the NEF 908 signals the AF 909. The NEF 908 may signal the AF 909 by sending a message to the AF 909. The signal may indicate that there has been a joint QoS fulfillment failure in respect of the flow group id. The signal may comprise an identifier of the flow group id. the signal at 9025 may indicate which of the UE comprised in the flow group caused the joint QoS fulfillment failure event to occur. The signal 9025 may identify the UE causing the joint QoS fulfillment failure event to occur. For example, in the present example, this signalling of 9025 may comprise an identifier of the second UE 902. In embodiments the NEF 908 signals the AF 909 by sending a message, the message may comprise an identifier of the flow group id, an indication of which of the UE comprised in the flow group caused the joint QoS fulfillment failure event to occur, and/or information identifying the UE causing the joint QoS fulfillment failure event to occur.

[0193] At 9026, the first PCF 906 signals the first SMF 904. The first PCF 906 may signal the first SMF 904 by sending a message to the first SMF 904. The signal may indicate to the first SMF 904 that resource flows established in respect of the first UE 901 are to be released and/or reconfigured. For example, the signal may indicate to the first SMF 904 that resources flows established in respect of the joint admission policy for the first UE 901 are to be released and/or reconfigured such that they are no longer consistent with the joint admission policy. Although not shown, the first SMF 904 may cause the release and/or reconfiguration of these resources in respect of the first UE 901 in response to the signal at 9026. In embodiments the first PCF 906 signals the first SMF 904 by sending a message to the first SMF 904, the message may include an indication that resource flows established in respect of the first UE 901 are to be released and/or reconfigured.

[0194] At 9027, the first PCF 906 signals the first SMF 904. The first PCF 906 may signal the first SMF 904 by sending a message to the first SMF 904. The signal may indicate to the first SMF 904 that resource flows established in respect of the third UE 903 are to be released and/or reconfigured. For example, the signal may indicate to the first SMF 904 that resources flows established in respect of the joint admission policy for the third UE 903 are to be released and/or reconfigured such that they are no longer consistent with the joint admission policy. Although not shown, the first SMF 904 may cause the release and/or reconfiguration of these resources in respect of the third UE 903 in response to the signal at 9027. In the embodiment the first PCF 906 signals the first SMF 904 by sending a message to the first SMF 904, the message may include an indication that resource flows established in respect of the third UE 903 are to be released and/or reconfigured.

[0195] At 9028, the first PCF 906 signals the NEF 908. The signal may indicate that the resources related to this joint QoS multi-modality session have been released and/or reconfigured. The first PCF 906 may indicate this release and/or reconfiguration by signalling, to the NEF 908, an indication that there has been a joint QoS fulfillment failure in respect of at least one of the first and third UEs.

[0196] Figures 10 and 11 illustrate example operations that may be performed by network function implemented on apparatus described herein. In particular, Figures 10 and 11 illustrate different aspects of the above examples of Figures 9A to 9C. Consequently, it is understood that features of the examples of Figures 9A to 9C may be implemented in the below operations, even without any explicit disclosure. Further, is understood that features of the examples of Figures 9A to 9C may be used to understand the following operations.

[0197] Figure 10 illustrates operations that may be performed by a network exposure function (NEF) implemented on an apparatus. It will be appreciated that the apparatus implementing the NEF may be implement or comprise only the NEF or may implement or comprises other network functions of a 5GC.

[0198] At 1001, the NEF receives, from an application function, a reservation request to reserve resources for an application function session (e.g., multi-modality session), the reservation request comprising an indication of a plurality of user equipment for which resources are to be reserved, and an indication that the plurality of user equipment are to be jointly admitted and/or their resources are to be jointly retained.

[0199] At 1002, the NEF determines that first policy control function is associated with a first set of user equipment of the plurality of user equipment. The first set may comprise a single user equipment. The first set may comprise a plurality of user equipment.

[0200] At 1003, the NEF signals, to the first policy control function, at least one first request to determine a first policy in respect of resources to be reserved for the first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set.

[0201] The NEF may: determine that a second policy control function is associated with a second set of user equipment of the plurality of user equipment; and signal (e.g., in response to the determination), to the second policy control function, at least one second request to determine a second policy in respect of resources to be reserved for the second set of user equipment, the at least one second request comprising an indication of a number of user equipment comprised in the second set. The second set may comprise a single user equipment. The second set may comprise a plurality of user equipment.

[0202] The NEF may receive, from the first and second policy control functions, respective indications that the first and second sets of user equipment were successfully jointly admitted, and signal, to the application function, an indication that the plurality of user equipment were successfully jointly admitted. The indication that the plurality of user equipment were successfully jointly admitted may correspond to an indication that at least one group policy was established in respect of both the first and second sets.

[0203] The NEF may receive, from the first policy control function, an indication that the first set of user equipment were successfully jointly admitted (e.g., an indication that a group policy was established in respect of the first set), receive, from the second policy control function, an indication that the second set of user equipment were not successfully jointly admitted (e.g., an indication that a group policy was not established in respect of the second set), and signal, to the application function, an indication that the plurality of user equipment were not successfully jointly admitted.

[0204] The NEF may signal, to the first policy control function, an indication that the plurality of user equipment were not successfully jointly admitted. [0205] Signalling the at least one first request may comprise signalling a plurality of first requests for resources to be reserved, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment. In other words, each first request may correspond to and uniquely identify a single (i.e., only one) user equipment comprised in the first set, while also providing an indication of the number of user equipment comprised in the first set. The plurality of first requests may be signalled when the first set comprises a plurality of user equipment.

[0206] Similarly, signalling the at least one second request may comprise signalling a plurality of second requests for resources to be reserved, each of the plurality of second requests comprising an indication of the number of user equipment comprised in the second set, and respectively comprising respective identifiers of different user equipment within the second set of user equipment. In other words, each second request may correspond to and uniquely identify a single (i.e., only one) user equipment comprised in the second set, while also providing an indication of the number of user equipment comprised in the second set. The plurality of second requests may be signalled when the second set comprises a plurality of user equipment.

[0207] The NEF may receive, from the first policy control function, an indication that resources could not be retained in respect of at least one of the first set of user equipment, identify all policy control functions that serve a flow group associated with the first set of user equipment; and signal, to at least one of said all policy control functions, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment. The at least one of said all policy control functions signalled may be a PCF that is not responsible for establishing a policy in respect of the at least one of the first set of user equipment for which resources could not be retained. The NEF may abstain from signalling the indication that resources could not be retained to any PCF that is responsible for establishing a policy in respect of the at least one of the first set of user equipment for which resources could not be reserved. It is understood that references made here to “resources could not be retained in respect of at least one of the first set of user equipment” indicates that there has been a QoS fulfillment failure in respect of retaining resources for that at least one of the first set of user equipment. In other words, a RAN entity (configured to provide network access to the at least one of the first set of user equipment) has been unable to retain resources (e.g., bearers and/or time/frequency resources) that fulfil the policy established by a PCF in respect of the at least one of the first set of user equipment.

[0208] The NEF may signal, to the application function, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment.

[0209] The NEF may, subsequent to signalling said at least one of said policy control functions, receive from said at least one of said policy control functions, an indication that resources could not be retained in respect of at least one of the plurality of user equipment served by the said at least one of said policy control functions.

[0210] Figure 11 illustrates example operations that may be performed by a first policy control function (PCF) implemented on an apparatus. It will be appreciated that the apparatus implementing the PCF may be implement or comprise only the PCF or may implement or comprises other network functions of a 5GC, such as the NEF of Figure 10. The first policy control function may be the first policy control function described above in relation to Figure 10. The first policy control function may correspond to the second policy control function described above in relation to Figure 10.

[0211] At 1101, the first PCF receives, from a network exposure interface, at least one first request to determine a first policy in respect of resources to be reserved for a first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set.

[0212] At 1102, the first PCF abstains from determining said first policy until the number of at least one first requests received equals the number of user equipment comprised in the first set.

[0213] The first PCF may attempt to determine said first policy when the number of at least one first requests received equals the number of user equipment comprised in the first set; and, when the first policy is successfully determined, signal to the network exposure function an indication that the first set of user equipment have been successfully jointly admitted; and when the first policy is not successfully determined, signal to the network exposure function an indication that the first set of user equipment have not been successfully jointly admitted.

[0214] When the first policy is successfully determined, the first PCF may provide the first policy to a session management function, receive, from the session management function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment, and signal, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment.

[0215] When the first policy is successfully determined, the first PCF may receive, from the network exposure function, an indication that at least one user equipment associated with a same flow group as the first set of user equipment has not had resources retained in respect of it, signal, to a session management function, an instruction to release and/or reconfigure resources for each user equipment in the first set of user equipment, and signal, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment.

[0216] The receiving the at least one first request may comprise receiving a plurality of first requests for resources to be reserved and/or retained, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment. [0217] In all of the above examples discussed with respect to the examples of Figures 10 and 11, the at least one first request may comprise at least one of: an identifier of at least one of the user equipment comprised in the first set; an identifier of a flow group to which the first set of user equipment are associated; and an indication that the user equipment in the first set are to be jointly admitted.

[0218] Further, in both of the above examples of Figures 10 and 11, the at least one first request may relate to the provision of a multi-modality service.

[0219] Further, in both of the above examples of Figures 10 and 11, the at least one first request may comprise support information for configuring for a Low Latency, Low Loss, Scalable Throughput data traffic.

[0220] It is understood that although the above examples are discussed in the context of first and second PCFs, the presently described techniques are not limited to only two PCFs, and may be applied when the UEs associated with a particular joint admission are associated to more than two PCFs.

[0221] The presently described techniques are associated with a plurality of advantages. For example, the presently described techniques provide support for handling multiple PCFs in the optimized path of multimodality call flow using the NEF (and, in general, supports handling multiple PCFs for joint admission).

[0222] Further, as the presently described techniques are implemented by 5GC entities (namely, the NEF and the PCFs), the AF providing the multi-modality service (which may comprise a third party function located in a different administrative domain to the 5GC entities), may not have to become aware of the complexity and/or configuration of 5GC. This may be useful for maintaining the security and/or integrity of the 5GC.

[0223] Further, the presently described techniques mean that there is no need to co-ordinate across multiple PCFs for joint policy handling, which provides scalability in 5GC.

[0224] Figure 2 shows an example of a control apparatus for a communication system, for example to be coupled to and/or for controlling a station of an access system, such as a RAN node, e.g. a base station, gNB, a central unit of a cloud architecture or a node of a core network such as an MME or S-GW, a scheduling entity such as a spectrum management entity, or a server or host, for example an apparatus hosting an NRF, NWDAF, AMF, SMF, UDM/UDR, and so forth. The control apparatus may be integrated with or external to a node or module of a core network or RAN. In some examples, base stations comprise a separate control apparatus unit or module. In other examples, the control apparatus can be another network element, such as a radio network controller or a spectrum controller. The control apparatus 200 can be arranged to provide control on communications in the service area of the system. The apparatus 200 comprises at least one memory 201, at least one data processing unit 202, 203 and an input/output interface 204. Via the interface the control apparatus can be coupled to a receiver and a transmitter of the apparatus. The receiver and/or the transmitter may be implemented as a radio front end or a remote radio head. For example, the control apparatus 200 or processor 201 can be configured to execute an appropriate software code to provide the control functions.

[0225] A possible wireless communication device will now be described in more detail with reference to Figure 3 showing a schematic, partially sectioned view of a communication device 300. Such a communication device is often referred to as user equipment (UE) or terminal. An appropriate mobile communication device may be provided by any device capable of sending and receiving radio signals. Nonlimiting examples comprise a mobile station (MS) or mobile device such as a mobile phone or what is referred to as a ’ smart phone’ , a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), personal data assistant (PDA) or a tablet provided with wireless communication capabilities, or any combinations of these or the like. A mobile communication device may provide, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia and so on. Users may thus be offered and provided numerous services via their communication devices. Non-limiting examples of these services comprise two-way or multi-way calls, data communication or multimedia services or simply an access to a data communications network system, such as the Internet. Users may also be provided broadcast or multicast data. Non-limiting examples of the content comprise downloads, television and radio programs, videos, advertisements, various alerts and other information.

[0226] A wireless communication device may be for example a mobile device, that is, a device not fixed to a particular location, or it may be a stationary device. The wireless device may need human interaction for communication, or may not need human interaction for communication. As described herein, the terms UE or “user” are used to refer to any type of wireless communication device.

[0227] The wireless device 300 may receive signals over an air or radio interface 307 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Figure 3, a transceiver apparatus is designated schematically by block 306. The transceiver apparatus 306 may be provided, for example, by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the wireless device.

[0228] A wireless device is typically provided with at least one data processing entity 301, at least one memory 302 and other possible components 303 for use in software and hardware aided execution of Tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The data processing, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 304. The user may control the operation of the wireless device by means of a suitable user interface such as keypad 305, voice commands, touch sensitive screen or pad, combinations thereof or the like. A display 308, a speaker and a microphone can be also provided. Furthermore, a wireless communication device may comprise appropriate connectors (either wired or' wireless) to other devices and/or for connecting external accessories, for example hands-free equipment, thereto.

[0229] Figure 4 shows a schematic representation of non-volatile memory media 400a (e.g. computer disc (CD) or digital versatile disc (DVD)) and 400b (e.g. universal serial bus (USB) memory stick) storing instructions and/or parameters 402 which when executed by a processor allow the processor to perform one or more of the steps of the methods of Figure 10 and/or Figure 11, and/or methods otherwise described previously.

[0230] As provided herein, various aspects are described in the detailed description of examples and in the claims. In general, some examples may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although examples are not limited thereto. While various examples may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0231] The examples may be implemented by computer software stored in a memory and executable by at least one data processor of the involved entities or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any procedures, e.g., as in Figure 10 and/or Figure 11, and/or otherwise described previously, may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media (such as hard disk or floppy disks), and optical media (such as for example DVD and the data variants thereof, CD, and so forth).

[0232] The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (AStudy ItemC), gate level circuits and processors based on multicore processor architecture, as nonlimiting examples. [0233] Additionally or alternatively, some examples may be implemented using circuitry. The circuitry may be configured to perform one or more of the functions and/or method steps previously described. That circuitry may be provided in the base station and/or in the communications device and/or in a core network entity.

[0234] As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analogue and/or digital circuitry);

(b) combinations of hardware circuits and software, such as:

(i) a combination of analogue 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 the communications device or base station to perform the various functions previously described; 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.

[0235] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, 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 integrated device.

[0236] The foregoing description has provided by way of non-limiting examples a full and informative description of some examples. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the claims. However, all such and similar modifications of the teachings will still fall within the scope of the claims.

[0237] In the above, different examples are described using, as an example of an access architecture to which the described techniques may be applied, a radio access architecture based on long term evolution advanced (LTE Advanced, LTE-A) or new radio (NR, 5G), without restricting the examples to such an architecture, however. The examples may also be applied to other kinds of communications networks having suitable means by adjusting parameters and procedures appropriately. Some examples of other options for suitable systems are the universal mobile telecommunications system (UMTS) radio access network (UTRAN), wireless local area network (WLAN or WiFi), worldwide interoperability for microwave access (WiMAX), Bluetooth®, personal communications services (PCS), ZigBee®, wideband code division multiple access (WCDMA), systems using ultra-wideband (UWB) technology, sensor networks, mobile ad-hoc networks (MANETs) and Internet Protocol multimedia subsystems (IMS) or any combination thereof.

[0238] Figure 5 depicts examples of simplified system architectures only showing some elements and functional entities, all being logical units, whose implementation may differ from what is shown. The connections shown in Figure 5 are logical connections; the actual physical connections may be different. It is apparent to a person skilled in the art that the system typically comprises also other functions and structures than those shown in Figure 5.

[0239] The examples are not, however, restricted to the system given as an example but a person skilled in the art may apply the solution to other communication systems provided with necessary properties.

[0240] The example of Figure 5 shows a part of an exemplifying radio access network. For example, the radio access network may support sidelink communications described below in more detail.

[0241] Figure 5 shows devices 500 and 502. The devices 500 and 502 are configured to be in a wireless connection on one or more communication channels with a node 504. The node 504 is further connected to a core network 506. In one example, the node 504 may be an access node such as (eZg)NodeB serving devices in a cell. In one example, the node 504 may be a non-3GPP access node. The physical link from a device to a (eZg)NodeB is called uplink or reverse link and the physical link from the (eZg)NodeB to the device is called downlink or forward link. It should be appreciated that (eZg)NodeBs or their functionalities may be implemented by using any node, host, server or access point etc. entity suitable for such a usage.

[0242] A communications system typically comprises more than one (eZg)NodeB in which case the (eZg)NodeBs may also be configured to communicate with one another over links, wired or wireless, designed for the purpose. These links may be used for signalling purposes. The (eZg)NodeB is a computing device configured to control the radio resources of communication system it is coupled to. The NodeB may also be referred to as a base station, an access point or any other type of interfacing device including a relay station capable of operating in a wireless environment. The (eZg)NodeB includes or is coupled to transceivers. From the transceivers of the (eZg)NodeB, a connection is provided to an antenna unit that establishes bi-directional radio links to devices. The antenna unit may comprise a plurality of antennas or antenna elements. The (eZg)NodeB is further connected to the core network 506 (CN or next generation core NGC). Depending on the deployed technology, the (eZg)NodeB is connected to a serving and packet data network gateway (S-GW +P-GW) or user plane function (UPF), for routing and forwarding user data packets and for providing connectivity of devices to one or more external packet data networks, and to a mobile management entity (MME) or access mobility management function (AMF), for controlling access and mobility of the devices. [0243] Examples of a device are a subscriber unit, a user device, a user equipment (UE), a user terminal, a terminal device, a mobile station, a mobile device, etc

[0244] The device typically refers to a mobile or static device (e.g. a portable or non-portable computing device) that includes wireless mobile communication devices operating with or without an universal subscriber identification module (USIM), including, but not limited to, the following types of devices: mobile phone, smartphone, personal digital assistant (PDA), handset, device using a wireless modem (alarm or measurement device, etc.), laptop and/or touch screen computer, tablet, game console, notebook, and multimedia device. It should be appreciated that a device may also be a nearly exclusive uplink only device, of which an example is a camera or video camera loading images or video clips to a network. A device may also be a device having capability to operate in Internet of Things (loT) network which is a scenario in which objects are provided with the ability to transfer data over a network without requiring human-to- human or human-to-computer interaction, e.g. to be used in smart power grids and connected vehicles. The device may also utilise cloud. In some applications, a device may comprise a user portable device with radio parts (such as a watch, earphones or eyeglasses) and the computation is carried out in the cloud.

[0245] The device illustrates one type of an apparatus to which resources on the air interface are allocated and assigned, and thus any feature described herein with a device may be implemented with a corresponding apparatus, such as a relay node. An example of such a relay node is a layer 3 relay (self-backhauling relay) towards the base station. The device (or, in some examples, a layer 3 relay node) is configured to perform one or more of user equipment functionalities.

[0246] Various techniques described herein may also be applied to a cyber-physical system (CPS) (a system of collaborating computational elements controlling physical entities). CPS may enable the implementation and exploitation of massive amounts of interconnected information and communications technology, ICT, devices (sensors, actuators, processors microcontrollers, etc.) embedded in physical objects at different locations. Mobile cyber physical systems, in which the physical system in question has inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robotics and electronics transported by humans or animals.

[0247] Additionally, although the apparatuses have been depicted as single entities, different units, processors and/or memory units (not all shown in Figure 5) may be implemented.

[0248] 5G enables using multiple input - multiple output (MIMO) antennas, many more base stations or nodes than the LTE (a so-called small cell concept), including macro sites operating in co-operation with smaller stations and employing a variety of radio technologies depending on service needs, use cases and/or spectrum available. 5G mobile communications supports a wide range of use cases and related applications including video streaming, augmented reality, different ways of data sharing and various forms of machine type applications (such as (massive) machine-type communications (mMTC), including vehicular safety, different sensors and real-time control). 5G is expected to have multiple radio interfaces, e.g. below 6GHz or above 24 GHz, cmWave and mmWave, and also being integrable with existing legacy radio access technologies, such as the LTE. Integration with the LTE may be implemented, at least in the early phase, as a system, where macro coverage is provided by the LTE and 5G radio interface access comes from small cells by aggregation to the LTE. In other words, 5G is planned to support both inter-RAT operability (such as LTE-5G) and inter-RI operability (inter-radio interface operability, such as below 6GHz - cmWave, 6 or above 24 GHz - cmWave and mmWave). One of the concepts considered to be used in 5G networks is network slicing in which multiple independent and dedicated virtual sub-networks (network instances) may be created within the same infrastructure to run services that have different requirements on latency, reliability, throughput and mobility.

[0249] The LTE network architecture is fully distributed in the radio and fully centralized in the core network. The low latency applications and services in 5G require to bring the content close to the radio which leads to local break out and multi-access edge computing (MEC). 5G enables analytics and knowledge generation to occur at the source of the data. This approach requires leveraging resources that may not be continuously connected to a network such as laptops, smartphones, tablets and sensors. MEC provides a distributed computing environment for application and service hosting. It also has the ability to store and process content in close proximity to cellular subscribers for faster response time. Edge computing covers a wide range of technologies such as wireless sensor networks, mobile data acquisition, mobile signature analysis, cooperative distributed peer-to-peer ad hoc networking and processing also classifiable as local cloud/fog computing and grid/mesh computing, dew computing, mobile edge computing, cloudlet, distributed data storage and retrieval, autonomic self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and/or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications).

[0250] The communication system is also able to communicate with other networks 512, such as a public switched telephone network, or a VoIP network, or the Internet, or a private network, or utilize services provided by them. The communication network may also be able to support the usage of cloud services, for example at least part of core network operations may be carried out as a cloud service (this is depicted in Figure 5 by “cloud” 514). This may also be referred to as Edge computing when performed away from the core network. The communication system may also comprise a central control entity, or a like, providing facilities for networks of different operators to cooperate for example in spectrum sharing.

[0251] The technology of Edge computing may be brought into a radio access network (RAN) by utilizing network function virtualization (NFV) and software defined networking (SDN). Using the technology of edge cloud may mean access node operations to be carried out, at least partly, in a server, host or node operationally coupled to a remote radio head or base station comprising radio parts. It is also possible that node operations will be distributed among a plurality of servers, nodes or hosts. Application of cloudRAN architecture enables RAN real time functions being carried out at or close to a remote antenna site (in a distributed unit, DU 508) and non-real time functions being carried out in a centralized manner (in a centralized unit, CU 510).

[0252] It should also be understood that the distribution of labour between core network operations and base station operations may differ from that of the LTE or even be non-existent. Some other technology advancements probably to be used are Big Data and all-IP, which may change the way networks are being constructed and managed. 5G (or new radio, NR) networks are being designed to support multiple hierarchies, where Edge computing servers can be placed between the core and the base station or nodeB (gNB). One example of Edge computing is MEC, which is defined by the European Telecommunications Standards Institute. It should be appreciated that MEC (and other Edge computing protocols) can be applied in 4G networks as well.

[0253] 5G may also utilize satellite communication to enhance or complement the coverage of 5G service, for example by providing backhauling. Possible use cases are providing service continuity for machine-to- machine (M2M) or Internet of Things (loT) devices or for passengers on board of vehicles, Mobile Broadband, (MBB) or ensuring service availability for critical communications, and future railway/maritime/aeronautical communications. Satellite communication may utilise geostationary earth orbit (GEO) satellite systems, but also low earth orbit (LEO) satellite systems, in particular megaconstellations (systems in which hundreds of (nano)satellites are deployed). Each satellite in the megaconstellation may cover several satellite-enabled network entities that create on-ground cells. The on- ground cells may be created through an on-ground relay node or by a gNB located on-ground or in a satellite.

[0254] The depicted system is only an example of a part of a radio access system and in practice, the system may comprise a plurality of (eZg)NodeBs, the device may have an access to a plurality of radio cells and the system may comprise also other apparatuses, such as physical layer relay nodes or other network elements, etc. At least one of the (eZg)NodeBs or may be a Home(eZg)nodeB. Additionally, in a geographical area of a radio communication system a plurality of different kinds of radio cells as well as a plurality of radio cells may be provided. Radio cells may be macro cells (or umbrella cells) which are large cells, usually having a diameter of up to tens of kilometers, or smaller cells such as micro-, femto- or picocells. The (eZg)NodeBs of Figure 5 may provide any kind of these cells. A cellular radio system may be implemented as a multilayer network including several kinds of cells. Typically, in multilayer networks, one access node.

Claims

We Claim:

1. A method for a network exposure function, the method comprising: receiving, from an application function, a reservation request to reserve resources for an application function session, the reservation request comprising an indication of a plurality of user equipment for which resources are to be reserved, and an indication that the plurality of user equipment are to be jointly admitted and/or that their resources are to be jointly retained; determining that a first policy control function is associated with a first set of user equipment of the plurality of user equipment; and signalling, to the first policy control function, at least one first request to determine a first policy in respect of resources to be reserved for the first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set.

2. The method as claimed in claim 1, the method comprising: determining that a second policy control function is associated with a second set of user equipment of the plurality of user equipment; and signalling, to the second policy control function, at least one second request to determine a second policy in respect of resources to be reserved for the second set of user equipment, the at least one second request comprising an indication of a number of user equipment comprised in the second set.

3. The method as claimed in claim 2, the method comprising: receiving, from the first and second policy control functions, respective indications that the first and second sets of user equipment were successfully jointly admitted; and signalling, to the application function, an indication that the plurality of user equipment were successfully jointly admitted.

4. The method as claimed in claim 2, the method comprising: receiving, from the first policy control function, an indication that the first set of user equipment were successfully jointly admitted; receiving, from the second policy control function, an indication that the second set of user equipment were not successfully jointly admitted; and signalling, to the application function, an indication that the plurality of user equipment were not successfully jointly admitted.

5. The method as claimed in claim 4, the method comprising signalling, to the first policy control function, an indication that the plurality of user equipment were not successfully jointly admitted.

6. The method as claimed in any one of claims 1 to 5, wherein signalling the at least one first request comprises signalling a plurality of first requests for resources to be reserved, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment.

7. The method as claimed in any one of claims 1 to 6, comprising: receiving, from the first policy control function, an indication that resources could not be retained in respect of at least one of the first set of user equipment; identifying all policy control functions that serve a flow group associated with the first set of user equipment; and signalling, to at least one of said all policy control functions, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment.

8. The method as claimed in claim 7, comprising signalling, to the application function, an indication that said resources could not be retained in respect of at least one of the plurality of user equipment.

9. The method as claimed in any one of claims 7 to 8, comprising, subsequent to signalling said at least one of said policy control functions, receiving from said at least one of said policy control functions, an indication that resources could not be retained in respect of at least one of the plurality of user equipment served by the said at least one of said policy control functions.

10. A method for a policy control function, the method comprising: receiving, from a network exposure interface, at least one first request to determine a first policy in respect of resources to be reserved for a first set of user equipment, the at least one first request comprising an indication of a number of user equipment comprised in the first set; and abstaining from determining said first policy until the number of at least one first requests received equals the number of user equipment comprised in the first set.

11. The method as claimed in claim 10, comprising: attempting to determine said first policy when the number of at least one first requests received equals the number of user equipment comprised in the first set; and when the first policy is successfully determined, signalling to the network exposure function an indication that the first set of user equipment have been successfully jointly admitted; and when the first policy is not successfully determined, signalling to the network exposure function an indication that the first set of user equipment have not been successfully jointly admitted.

12. The method as claimed in claim 11, when the first policy is successfully determined, the method comprising: providing the first policy to a session management function; receiving, from the session management function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment; and signalling, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment.

13. The method as claimed in claim 11, when the first policy is successfully determined, the method comprising: receiving, from the network exposure function, an indication that at least one user equipment associated with a same flow group as the first set of user equipment has not had resources retained in respect of it; signalling, to a session management function, an instruction to release and/or reconfigure resources for each user equipment in the first set of user equipment; and signalling, to the network exposure function, an indication that resources were not retained in respect of at least one user equipment of the first set of user equipment.

14. The method as claimed in any one of claims 10 to 13, wherein the receiving the at least one first request comprises receiving a plurality of first requests for resources to be reserved and/or retained, each of the plurality of first requests comprising an indication of the number of user equipment comprised in the first set, and respectively comprising respective identifiers of different user equipment within the first set of user equipment.

15. The method as claimed in any one of claims 10 to 14, wherein the at least one first request comprises at least one of: an identifier of at least one of the user equipment comprised in the first set; an identifier of a flow group to which the first set of user equipment are associated; and an indication that the user equipment in the first set are to be jointly admitted.

16. The method as claimed in any one of claims 10 to 15, wherein the at least one first request relates to the provision of a multi-modality service.

17. The method as claimed in any one of claims 10 to 16, wherein the at least one first request comprises support information for configuring for a Low Latency, Low Loss, Scalable Throughput data traffic.

18. An apparatus comprising means for performing the method of any one of claims 1 to 9.

19. An apparatus comprising: at least one processor; and at least one memory storing instructions for a network exposure functions, wherein the instructions when executed by the at least one processor cause the apparatus to perform the method of any one of claims 1 to 9.

20. An apparatus comprising means for performing any one of claims 10 to 17.

21. An apparatus comprising: at least one processor; and at least one memory storing instructions for a policy control function, wherein the instructions when executed by the at least one processor cause the apparatus to perform the method of any one of claims 10 to 17.

22. A computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform the method of any one of claims 1 to 9.

23. A computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform any one of claims 10 to 17.

24. A computer-readable medium comprising instructions which, when executed by an apparatus, cause the apparatus to perform the method of any one of claims 1 to 9.

25. A computer-readable medium comprising instructions which, when executed by an apparatus, cause the apparatus to perform the method of any one of claims 10 to 17.