A.2 Downlink Media path setup for MBMS Delivery
23.4683GPPGroup Communication System Enablers for LTE (GCSE_LTE)Release 17Stage 2TS
A.2.1 General
This clause describes two procedures for establishing MBMS Delivery on the downlink:
– using pre-established MBMS bearers, or
– using dynamic establishment of MBMS bearers
A.2.2 Use of Pre-established MBMS bearers
In this scenario, the GCS AS pre-establishes MBMS bearer(s) in certain pre-configured areas before the start of the group communication session. When a UE originates a request for group communication for one of these areas, the pre-established MBMS bearer(s) is used for the DL traffic.
Figure A.2.2-1: Use of Pre-established MBMS Bearers
1. The GCS AS pre-establishes the MBMS bearers for the group communication session according to the procedures defined in clause 5.1.2.3.1. The BM-SC returns the MBMS service description associated with the MBMS bearer(s) to the GCS AS.
2. The UE establishes a group communication session with the GCS AS. The GCS AS passes the service description associated with the MBMS bearer service to the UE. The UE obtains the TMGI(s), identifying the MBMS bearer (s), from the service description.
3. The UE starts monitoring the MSI and MCCH of received MBSFN broadcast(s) for the TMGI(s).
4. Having detected a TMGI on MCCH the UE monitors the MSI and receives the DL data on the MTCH corresponding to the TMGI.
A.2.3 Use of Dynamic MBMS bearer establishment
In this scenario, the GCS AS uses a unicast bearer for communication with the UE on the DL at the start of the group communication session. When the GCS AS decides to use an MBMS bearer for the DL data, the GCS AS establishes one using the procedures defined in clause 5.1.2.3.1. The GCS AS provides the service description associated with MBMS bearer(s), obtained from the BM-SC, to the UE. The UE starts using the MBMS bearer(s) to receive DL data and stops using the unicast bearer for the DL data.
NOTE: The GCS AS logic for determining when to establish the new MBMS Delivery bearer is implementation specific. For example, the GCS AS could decide to establish the MBMS delivery based on the location of the UE’s that are a part of the group communication session.
Figure A.2.3-1: Use of Dynamic MBMS Bearer Establishment
1. The UE establishes a group communication session with the GCS AS.
2. The downlink data is sent by Unicast Delivery.
3. The GCS AS establishes the MBMS bearer(s) for the group communication session according to the procedures defined in clause 5.1.2.3.1. The BM-SC returns the service description associated with the MBMS bearer(s) to the GCS AS.
4. The GCS AS provides the service description associated with the MBMS bearer(s) to the UE. The UE obtains the TMGI(s) from the service description.
5. The UE starts monitoring the MSI and MCCH of received MBSFN broadcast(s) for the TMGI(s).
6. Having detected a TMGI on MCCH the UE monitors the MSI and receives the DL data on the MTCH corresponding to the TMGI.
7. The UE notifies the GCS AS that it is receiving the data over MBMS for the given TMGI. The GCS AS stops sending DL data over unicast to the UE.
Annex B (Informative):
Change history
|
Change history |
|||||||
|
Date |
Meeting |
TDoc |
CR |
Rev |
Cat |
Subject/Comment |
New version |
|
2014-02 |
SP-63 |
SP-140118 |
– |
– |
– |
MCC Editorial Update for Presentation to TSG SA for Approval |
1.0.0 |
|
2014-02 |
SP-63 |
– |
– |
– |
– |
MCC Editorial update for publication after TSG SA approval |
12.0.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0007 |
1 |
F |
Update clauses 5.2 & 5.4 for GCSE |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0008 |
2 |
F |
Update clause 4.2.1 for GCSE |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0009 |
1 |
F |
Update clause 4.2.3 for GCSE |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0010 |
2 |
F |
Update of GC1reference point for GCSE |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0016 |
1 |
F |
Fix misleading text on uplink bearer |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0017 |
1 |
F |
Corrections to the TMGI allocation and deallocation procedures |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0018 |
2 |
F |
Proposed change of terminology for used TMGIs over MB2 |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0019 |
2 |
F |
Charging requirements for GCSE_LTE |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0021 |
2 |
F |
Clarifications to service description from BM-SC |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0032 |
1 |
F |
Clarification of actions consequent upon TMGI expiry |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0035 |
1 |
F |
Deactivate the MBMS bearer procedure |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0037 |
2 |
F |
Priority and Pre-emption for GCS |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0038 |
1 |
F |
Clarifications to security requirements |
12.1.0 |
|
2014-06 |
SP-64 |
SP-140259 |
0039 |
1 |
F |
Flow ID allocation by BM-SC only |
12.1.0 |
|
2014-09 |
SP-65 |
SP-140420 |
0022 |
2 |
F |
Clarifications to roaming models and MBMS Delivery media flow in the figures |
12.2.0 |
|
2014-09 |
SP-65 |
SP-140420 |
0044 |
1 |
F |
Requirements for MB2 and GC1 |
12.2.0 |
|
2014-12 |
SP-66 |
SP-140678 |
0050 |
1 |
F |
Clarifications for priority related PCRF actions |
12.3.0 |
|
2014-12 |
SP-66 |
SP-140678 |
0055 |
1 |
F |
Add missing FlowID parameter to ‘Activate MBMS Bearer Request’ |
12.3.0 |
|
2015-03 |
SP-67 |
SP-150018 |
0048 |
2 |
D |
Abbreviations – addition and correction |
12.4.0 |
|
2015-03 |
SP-67 |
SP-150018 |
0049 |
2 |
F |
Clarification on Service Continuity from MBMS delivery to Unicast delivery |
12.4.0 |
|
2015-03 |
SP-67 |
SP-150027 |
0056 |
2 |
C |
Paging Priority for Push To Talk |
13.0.0 |
|
2015-06 |
SP-68 |
SP-150227 |
0059 |
1 |
A |
Correct FlowID per agreement with CT WG3 |
13.1.0 |
|
2015-06 |
SP-68 |
SP-150227 |
0064 |
1 |
A |
Correction of specification of Group Call suspension |
13.1.0 |
|
2015-09 |
SP-69 |
SP-150489 |
0066 |
1 |
A |
Clarify BM-SC behaviour in case of overlapping broadcast areas |
13.2.0 |
|
2015-09 |
SP-69 |
SP-150504 |
0067 |
3 |
B |
Adding ProSe UE-to-Network Relaying to the GCSE_LTE architecture |
13.2.0 |
|
2015-09 |
SP-69 |
SP-150506 |
0070 |
2 |
B |
MBMS bearer establishment and update with cell ID list |
13.2.0 |
|
2015-12 |
SP-70 |
SP-150616 |
0075 |
5 |
F |
Clarification on the elements of the MBMS service description |
13.3.0 |
|
2017-03 |
– |
– |
– |
– |
– |
Update to Rel-14 version (MCC) |
14.0.0 |
|
2017-12 |
SP-78 |
SP-170928 |
0080 |
1 |
C |
MBMS session setup procedure /event notification alignment with RAN WG3 |
15.0.0 |
|
2017-12 |
SP-78 |
SP-170928 |
0081 |
6 |
F |
MB2 improvements for GCS AS to be able to request application of FEC and/or RoHC to a MBMS bearer |
15.0.0 |
|
2019-09 |
SP-85 |
SP-190602 |
0082 |
– |
F |
Fix missed update to Modify MBMS Bearer procedure – add resources reporting |
15.1.0 |
|
2020-07 |
– |
– |
– |
– |
– |
Update to Rel-16 version (MCC) |
16.0.0 |
|
2022-03 |
– |
– |
– |
– |
– |
Update to Rel-17 version (MCC) |
17.0.0 |