3 Definitions of terms and abbreviations

23.2473GPPArchitectural enhancements for 5G multicast-broadcast servicesRelease 18TS

3.1 Terms

For the purposes of the present document, the terms and definitions defined in TR 21.905 [1] and the following apply:

5GC Individual MBS traffic delivery: 5G CN receives a single copy of MBS data packets and delivers separate copies of those MBS data packets to individual UEs via per-UE PDU sessions, hence for each such UE one PDU session is required to be associated with a Multicast MBS Session.

5GC Shared MBS traffic delivery: 5G CN receives a single copy of MBS data packets and delivers a single copy of those MBS data packets to a RAN node.

Area Session Identifier: A unique identifier within an MBS Session used for an MBS session with location dependent content. When present, the Area Session ID, together with the TMGI, is used to uniquely identify the data flow of an MBS Session in a specific MBS service area.

Associated PDU Session: A PDU Session associated to a multicast MBS session that is used for 5GC Individual MBS traffic delivery method and for signalling related to a user’s participation in a multicast MBS session such as join and leave requests.

Associated QoS Flow: A unicast QoS Flow that belongs to the associated PDU Session and is used for 5GC Individual MBS traffic delivery method. The associated QoS Flow is mapped from a multicast QoS Flow in a multicast MBS session.

Broadcast communication service: A 5GS communication service in which the same service and the same specific content data are provided simultaneously to all UEs in a geographical area (i.e. all UEs in the broadcast coverage area are authorized to receive the data).

NOTE 1: For the broadcast communication service, the content provider and network may not be aware whether the authorized UEs are actually receiving the data being delivered.

Broadcast MBS session: An MBS session to deliver the broadcast communication service. A broadcast MBS session is characterised by the content to send and the geographical area where to distribute it.

Broadcast service area: The area within which data of one or multiple Broadcast MBS session(s) are sent.

MBS QoS Flow: The finest granularity for QoS forwarding treatment for MBS data. Providing different QoS forwarding treatment requires separate MBS QoS Flows in 5GS supporting MBS.

MBS Service Announcement: Mechanism to allow users to be informed about the available MBS services.

MBS session: A multicast MBS session or a broadcast MBS session.

MBS service area: The area within which data of one Multicast or Broadcast MBS session may be sent. For location dependent MBS, for each MBS service area, an Area Session ID, which is unique per MBS Session ID, is allocated and the same location dependent content data for an MBS session is delivered to the UE(s) within an MBS service area.

Multicast communication service: A 5GS communication service in which the same service and the same specific content data are provided simultaneously to a dedicated set of UEs (i.e. not all UEs in the coverage of the MBS service area are authorized to receive the data).

NOTE 2: For multicast communication service, the content provider and network can be aware whether the authorized UEs are actually receiving the data being delivered.

Multicast MBS session: An MBS session to deliver the multicast communication service. A multicast MBS session is characterised by the content to send, by the list of UEs that may receive the service and optionally by a geographical area where to distribute it.

3.2 Abbreviations

For the purposes of the present document, the abbreviations given in TR 21.905 [1], TS 23.501 [5] and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905 [1].

CDN Content Delivery Network

FEC Forward Error Correction

FSA Frequency Selection Area

LL SSM Lower Layer SSM

MBMS Multimedia Broadcast/Multicast Service

MBS Multicast/Broadcast Service.

MBSF Multicast/Broadcast Service Function.

MBSTF Multicast/Broadcast Service Transport Function.

MB-SMF Multicast/Broadcast Session Management Function.

MB-UPF Multicast/Broadcast User Plane Function

PTM Point To Multipoint

PTP Point To Point

SSM Source Specific IP Multicast address.

TMGI Temporary Mobile Group Identity