rjb1000
commented
1 year ago Based on discussion with @kuehnhammer on today's 5G-MAG Reference Tools call, he has convinced me that the figures in TS 103 720 are incorrect with respect to the reference model for eMBMS.
- The choice of the left hand deployment architecture by R&S seems valid.
- It potentially allows a single 5G Broadcast Transmitter (Core) to manage multiple 5G Broadcast Transmitter (Radio Access Network) instances.
- The choice of the right hand deployment architecture seems equally valid.
Reference architecture
Amend figure 5.2.1-1 to explicitly depict an MCE between the MME and the eNodeB.
M3 must be shown between the MME and the MCE.
Two deployment options
Replace figure 5.2.2-1 with two deployment options.
M2 exposed between Core and RAN
This corresponds to the R&S deployment choice. M3 (between the MME and MCE) is hidden inside the Core.
M3 exposed between Core and RAN
This is a modification of the deployment model already documented in TS 103 720, with M3 now terminating on an MCE instantiated inside the eNodeB. M2 is hidden inside the eNodeB.
dvargasparedero
Context
The depiction of interface M3 between MME and eNodeB is unclear.
Problem description
TS 136 300 15.1.1 defines interface M3 between MME and MCE, and M2 between MCE and eNodeB. For the logical MCE entity, two deployment options are given: a centralized MCE serving multiple eNodeBs, and a distributed architecture where each eNodeB is deployed with an MCE alongside it (see Figure 15.1.1-2), and mandates that in both cases the M2 interface between MCE and eNodeB be kept.
The architecture and deployment diagrams in TS 103 720 show a direct M3 interface between eNodeB and MME, which does not match the above.
Additionally, the currently available commercial broadcast core by R&S uses interfaces M1 and M2 for communication with the eNodeB, i.e. it has an integrated MCE. To maintain compatibility with new cores, it would be good if the TS reflects this model as well.
Suggested solution
Add the MCE component in Figure 5.2.1-1, and possibly adapt Figure 5.2.2-1 to show the MCE as part of the integrated core components with M1 and M2 as RAN interfaces; and/or add another deployment model with distributed MCEs alongside the eNodeB (keeping the M2 interface).