N310 and N311 are number of out-of-sync and in-sync indications respectively and T310 and T311 are timers related to RLF and RRC Conncetion Re-establishment procedures.
N310
Number of consecutive out-of-sync indications from lower layers. If reached, it triggers T310 timer.
T310
Start Upon detecting physical layer problems i.e. upon receiving N310 consecutive out-of-sync indications from lower layers and stop upon receiving N311 consecutive in-sync indications from lower layers, upon triggering the handover procedure and upon initiating the connection re-establishment procedure.
Upon expiry - If security is not activated: go to RRC_IDLE, else: initiate the connection re-establishment procedure.
N311
Number of consecutive in-sync indications from lower layers,time bound by T311.
T311
Start Upon initiating the RRCconnection reestablishmentmprocedure(RRE). RRE Procedure includes Cell Reselection and RRC Connection. This timer is for Cell Reselection process only. Stop upon Selection of a suitable E-UTRA cell or a cell using another RAT.
Upon expiry - UE enter RRC_IDLE.
