Multicast Architecture Enhancement for 5G Media Streaming
The present document identifies and evaluates potential enhancements to the 5G Media Streaming (5GMS) [1] in order to provide multicast-broadcast media streaming services. It has the following objectives:
- Define scenarios where multicast ingestion or multicast distribution might be used, including potential IGMP termination options [2], [3], and [4]. Examples for such collaboration scenarios are transparent multicast delivery, multicast linear IPTV delivery, hybrid unicast/multicast (e.g. MooD or service continuity), and multicast Adaptive Bit Rate (ABR) for Over the Top (OTT) live streaming.
- Identify the relevant key issues and gaps in 5GMS to support the above scenarios based on the existing 5GS multicast architecture.
- Document architecture extensions and procedures to support the above-defined scenarios.
- Identify protocols to support the above extensions and procedures in 5GMS.
- Identify Procedures for managing downlink multicast streaming and session lifecycle.
- Select a subset of relevant scenarios that should be supported in extensions to 5G Media Streaming.
A revision of the present document identifies and evaluates a set of potential improvements and extensions, referred to as Key Issues:
- In-session Unicast Repair for MBS Object Distribution.
- MBS User Service and Delivery Protocols for eMBMS.
- Selected MBMS Functionalities not supported in MBS.
For each of the above key topics, the following objectives are identified:
1. Document the key topics in more detail, in particular how they relate to the 3GPP Media Delivery architecture and/or the MBS User Service architecture.
2. Study collaboration scenarios between the Application Service Provider and the 5G System and for each of the key topics.
3. Based on existing architectures, develop one or more deployment architectures that address the key topics and the collaboration models.
4. Map the key topics to basic functions and develop high-level call flows.
5. Identify the issues that need to be solved.
6. Provide candidate solutions including call flows, protocols and APIs for each of the identified issues.
7. Coordinate work with other 3GPP groups e.g. SA2, SA3, SA5, SA6 and others as needed.
8. Coordinate work with external organizations such as DASH-IF, CTA WAVE, ISO/IEC JTC29 WG3 (MPEG Systems), 5G-MAG, DVB or IETF, as needed.
9. Identify gaps and recommend potential normative work for stage-2 and stage-3, including which existing specifications would be impacted and/or if any new specifications would preferably be developed.