Add TS 29.561 to wiki page about relevant 5G MBS specifications

[TuanTranBPK]

I look around the documents and specifications on N6mb/Nmb9 for MB-UPF but don't find them on the wiki. It take a while to figure out the appropriate 3GPP specification.

[jordijoangimenez]

@rjb1000 @Borjis131 you may be across this. Could you have a quick look at the wiki https://github.com/5G-MAG/Standards/wiki/5G-Multicast-Broadcast-Services-(5MBS):-Relevant-Specifications and detect any missings?

There may be some interfaces between MBS core network components not referenced.

[rjb1000]

SA2's TS 23.247 defines reference points N6mb and Nmb9, and the NOTE to figure 5.1-2 specifies that they are functionally identical to each other.

• Clause 8.2 defines the user plane protocol stacks for shared MBS delivery at these reference points, including options for a UDP tunnel or just plain IP multicast.
• Clause 8.2 also specifies that the user plane protocol stack for individual delivery is that same as that specified in clause 8.3.1 of TS 23.501.

I searched in vain for a separate CT3 specification at this reference point. But maybe that's because the above is all that needs to be specified?

[Borjis131]

As @rjb1000 pointed out, Clause 8.2 of 3GPP TS 23.247 has the same information as Clause 20.3 of 3GPP TS 29.561

I do not know if there is more information about N6mb/N9mb in other 3GPP specifications but I suggest you to follow 3GPP TS 23.247 for the high level architecture and then extract the relevant bits of the protocols and APIs needed from the other specifications.

[TuanTranBPK]

That could be an easy understanding for someone who has been working on the subject for a while. But it's not obvious for someone that has just started on the subject and needs to have a big picture from all specifications related to the subject.

I guess that the wiki page is an entry point for everybody. I have no problem to not include TS 29.561, it's just a suggestion.

[Borjis131]

I completely agree with you @TuanTranBPK, starting with these topics always has a steep learning curve. The thing is, that adding another specification to the list that doesn't add more information can be a bit overwhelming for the user that is starting too.

Anyway, I am open to add it if you guys find it useful, this was just my opinion.

[jordijoangimenez]

Some sort of pointers to which specs (+clauses) contain info on reference points / interfaces, etc, would be useful. I suggest to ping David Vargas and get this job started under 5G-MAG's WG CD. It worked well when we did the RAN profiling and perhaps we can do a next level of detail for these things

[TuanTranBPK]

The wiki page "5G-Multicast-Broadcast-Services-(5MBS):-RAN-Procedures-for-MBS-Broadcast" provides some good pointers to which spec/clause for a particular topic. It would be nice if we could do similar thing for the Core Network part, for example the pointers spec/clause for each interface related to 5G MBS.