We use this procedure to release RRC Connection. This procedure will release of the established radio bearers as well as radio resources.
Initiation:
Network will initiate RRC Connection release to move the UE from RRC_CONNECTED to RRC_IDLE.
Below are the steps performed by UE on reception of RRCRelease
stop timer T380, if running;
stop timer T320, if running;
If RRCRelease message includes the cellReselectionPriorities, then store the cell reselection priority information.
If the RRCRelease includes suspendConfig, then reset MAC and release default MAC cell group.
-> suspend all SRB(s) and DRB(s), except SRB0;
-> indicate PDCP suspend to lower layers of all DRBs;
Source TS 38.331