Advanced Media Delivery - 5G Multicast Broadcast Services

[dsilhavy]

Background

In the 5G-MAG Reference Tools meetings on October 17th and October 24th we dived into 3GPP Release 19 features, specifically looking at Advanced Media Delivery for 5G Multicast Broadcast Services.

In this thread, we will discuss the different topics that were presented and what it means to add them to the 5G-MAG Reference Tools.

Links

• Slides: Link

Main topics

• In-session Unicast Repair for MBS/MBMS Object Distribution
• Time Synchronization

Related Discussions

• Strategy for adding features from new 3GPP releases to the reference tools

[dsilhavy]

In-session Unicast Repair for MBS/MBMS Object Distribution

Background

For live and low-latency live services using the Object Distribution Method in MBS, in certain cases the transmission of an object is not successful. In this case, unicast repair for individual MBS Clients can improve the service quality. However, the timing of such requests needs to be carefully studied in order to avoid network overloads or significant latencies in the delivery.

Questions

Links

• Project board

Specifications

• TR 26.802, In-session unicast repair for MBS Object Distribution as introduced in clause 5.9
• Stage 3: There are cross-references between the stage 3 specifications for MBS and MBMS

5G-MAG Reference Tools

Which existing components are affected?

• MBS
  • MBSTF
• MBMS
  • MBMS Transmitter
  • MBMS Modem?
  • Android MBMS Client?

What needs to be done from a high level?

How is the support in required 3rd party libraries & frameworks?

What is the estimated effort?

What is in scope of a first MVP/PoC?

Who is interested and can contribute?

[dsilhavy]

Time Synchronization

Background

MBS Client is required to be time-synchronized with the 5G System (i.e. MBSF, MBSTF and/or the MBS AS) with a precision of at least ±1s to support certain MBS User Service functions.

Similar to MBMS, two options are provided in order to achieve this functionality:

1. Usage of SIB9: MBS Client may obtain time information from SIB9 to synchronize the system clock of the UE to UTC wallclock time. If SIB9 is carried in the radio frequency carrying the MBS Distribution Session, the relevant MBS functions shall be time-synchronized to the same UTC wallclock as the NR SIB9 information to a tolerance of ±100 ms or better.
2. Time service: The MBS AS hosts a time service. The MBS Client may obtain time information from this service to synchronize its clock. These may be announced in the User Service Description

Questions

• Do we have a preference for one of the options?
• Candidate for a 5G-MAG challenge?

Links

• Project Board

Specifications

• Stage-2: S4-250390
• Stage-3: S4-251511
• Related dash.js documentation on client-side time synchronization: https://dashif.org/dash.js/pages/usage/clock-sync.html

5G-MAG Reference Tools

Which existing components are affected?

What needs to be done from a high level?

How is the support in required 3rd party libraries & frameworks?

• Check whether SIB9 is supported in srsRAN

What is the estimated effort?

What is in scope of a first MVP/PoC?

Who is interested and can contribute?