M.2 Operation Overview
36.3003GPPEvolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN)Overall descriptionRelease 17Stage 2TS
Table M.2-1 below gives a network overview of the DC operations.
Table M.2-1: Dual Connectivity Operations
|
# |
Network Action |
Corresponding clause |
Remarks |
|
1 |
Intra-PCell Handover |
10.1.2.8.2.1 Intra-MeNB handover involving SCG change |
Causes also intra-PSCell Change or Intra-SeNB Change. Also used for KeNB refresh. Done via Handover like in Rel-8; SCG can be retained during the Handover. |
|
2 |
Intra-PSCell SCG Change |
10.1.2.8.2 SeNB Modification (MeNB initiated SeNB Modification) 10.1.2.8.2 SeNB Modification (SeNB initiated SeNB Modification) |
Also used for S-KeNB refresh. Does not require intra-PCell Handover. |
|
3 |
Intra-MeNB Handover |
10.1.2.8.2.1 Intra-MeNB handover involving SCG change |
Causes also intra-PSCell Change or Intra-SeNB Change. Done via Handover like in Rel-8; SCG can be retained during the Change. |
|
4 |
Intra-SeNB SCG Change |
10.1.2.8.2 SeNB Modification (MeNB initiated SeNB Modification) 10.1.2.8.2 SeNB Modification (SeNB initiated SeNB Modification) |
Requires SCG change but does not require intra-PCell Handover. |
|
5 |
Inter-MeNB Handover |
10.1.2.8.5 MeNB to eNB Change 10.1.2.8.7 eNB to MeNB change 10.1.2.8.8 Inter-MeNB handover without SeNB change |
Done via Handover like in Rel-8; Involves SCG release, or intra SeNB Change or inter-SeNB Change. |
|
6 |
Inter-SeNB SCG Change |
10.1.2.8.4 Change of SeNB |
Requires SCG change. |
|
7 |
SCG addition by MeNB |
10.1.2.8.1 SeNB Addition 10.1.2.8.7 eNB to MeNB change |
Only the MeNB can request an SCG to be added. |
|
8 |
SCG SCell addition by MeNB |
10.1.2.8.2 SeNB Modification (MeNB initiated SeNB Modification) |
Only the MeNB can request to add SCells to the SCG.If the SeNB wants to use the new SCell as PSCell it needs to initiate an SeNB modification. |
|
9 |
Non-last SCG SCell release by MeNB |
10.1.2.8.2 SeNB Modification (MeNB initiated SeNB Modification) |
For requesting the release of the last SCG SCell i.e. PSCell, the MeNB has to request SCG release instead. |
|
10 |
Non-last SCG SCell release by SeNB |
10.1.2.8.2 SeNB Modification (SeNB initiated SeNB Modification) |
For requesting the release of the last SCG SCell i.e. PSCell, the SeNB has to request SCG release instead. The SeNB can request to release the PSCell only if it also chooses a new PSCell. |
|
11 |
SCG release by MeNB |
10.1.2.8.3 SeNB Release (MeNB initiated SeNB Release) |
The MeNB can always request the release of the SCG and the SeNB has to comply. |
|
12 |
SCG release by SeNB |
10.1.2.8.3 SeNB Release (SeNB initiated SeNB Release) |
The SeNB can always request the release of the SCG and the MeNB has to comply |
|
13 |
SCG bearer addition by MeNB |
10.1.2.8.2 SeNB Modification (MeNB initiated SeNB Modification) (10.1.2.8.1 MeNB initiated SeNB Addition) |
If this is the first bearer to be added in the SeNB, SCG addition is used instead. |
|
14 |
SCG bearer release |
10.1.2.8.2 SeNB Modification (MeNB initiated SeNB Modification) 10.1.2.8.2 SeNB Modification (SeNB initiated SeNB Modification) |
Allowed for both the MeNB and the SeNB, but the SeNB cannot request to release the last SCG bearer if that would result in no bearers in SeNB – SCG release should be used instead. The SeNB cannot initiate the release of an SCG bearer and make changes to SCG-Config at the same time e.g. change the configuration of the physical layer. |
|
15 |
Split bearer addition by MeNB |
10.1.2.8.2 SeNB Modification (MeNB initiated SeNB Modification) |
|
|
16 |
Split bearer release |
10.1.2.8.2 SeNB Modification (MeNB initiated SeNB Modification) 10.1.2.8.2 SeNB Modification (SeNB initiated SeNB Modification) |
Allowed for both the MeNB and the SeNB, but the SeNB cannot request to release the last split bearer if that would result in no bearers in SeNB – SCG release should be used instead. The SeNB cannot initiate the release of an SCG bearer and make changes to SCG-Config at the same time e.g. change the configuration of the physical layer. |
|
17 |
MCG to SCG bearer type change (and vice versa) |
10.1.2.8.2 SeNB Modification (MeNB initiated SeNB Modification) 10.1.2.8.2 SeNB Modification (SeNB initiated SeNB Modification) |
Either the MeNB or the SeNB can request to release an SCG bearer. Done via SCG change, i.e. L2 reset is required for the UE. The SeNB can only request change from SCG to MCG by requesting release of SCG bearer. The MeNB makes the decision on whether to release the DRB entirely or change it to MCG bearer. |
|
18 |
MCG to Split Bearer Change (and vice versa) |
10.1.2.8.2 SeNB Modification (MeNB initiated SeNB Modification) 10.1.2.8.2 SeNB Modification (SeNB initiated SeNB Modification) |
The SeNB can always request to release the SCG part of a split bearer. Done via SCG change, i.e. L2 reset is required for the UE. MeNB makes the decision on whether to release the DRB entirely or change it to MCG bearer. |
Annex N (informative):
Sidelink communication