Editing My Intra-NR Notes (section)

== 9.2.3 Mobility in RRC_CONNECTED ==

=== 9.2.3.1	Overview ===

Network controlled mobility applies to UEs in RRC_CONNECTED and is categorized into two types of mobility: cell level mobility and beam level mobility. Beam level mobility includes intra-cell beam level mobility and inter-cell beam level mobility.

'''Cell Level Mobility''' requires explicit RRC signalling to be triggered, i.e. handover. For inter-gNB handover, the signalling procedures consist of at least the following elemental components illustrated in Figure 9.2.3.1-1:

<center>[[File:Inter-gNB handover procedures.png|Inter-gNB handover procedures sequence diagram]]</center>

:1.	The source gNB initiates handover and issues a HANDOVER REQUEST over the Xn interface.
:2.	The target gNB performs admission control and provides the new RRC configuration as part of the HANDOVER REQUEST ACKNOWLEDGE.
:3.	The source gNB provides the RRC configuration to the UE by forwarding the RRCReconfiguration message received in the HANDOVER REQUEST ACKNOWLEDGE. The RRCReconfiguration message includes at least cell ID and all information required to access the target cell so that the UE can access the target cell without reading system information. For some cases, the information required for contention-based and contention-free random access can be included in the RRCReconfiguration message. The access information to the target cell may include beam specific information, if any.
:4.	The UE moves the RRC connection to the target gNB and replies with the RRCReconfigurationComplete.

NOTE 1:	User Data can also be sent in step 4 if the grant allows.

See spec for full details.

<center>[[My 3GPP 38.300 Notes|To My 3GPP 38.300 Notes]]</center>