LTE Timers

Timer	Start	Stop	At Expiry	Recommended Value
T300	This timer is started when the UE sends RRCConnectionRequest.	Reception of RRCConnectionSetup or RRCConnectionReject message, cell re-selection and upon abortion of connection establishment by upper layers	the UE directly enters the RRC_IDLE state	200ms
T301	This timer is started when the UE sends an RRC Connection Reestablishment Request message	The timer is stopped if the UE receives an RRC Connection Reestablishment or RRC Connection Reestablishment Reject message. The timer is also stopped if the selected cell becomes an unsuitable cell.	the UE enters the RRC_IDLE mode.	200ms
T302	Reception of RRCConnectionReject while performing RRC connection establishment	This timer is stopped when the UE enters the RRC_CONNECTED mode or performs cell reselection	Informs upper Layers	4s
T303	Starts when access is barred while performing RRC CONNECTION ESTABLISHMENT for MO(Mobile Originating) calls	Upon entering RRC_CONNECTED and upon cell re-selection	Informs upper Layers
T304	Starts at the Receipt of RRC CONNECTION RECONFIGURATION message along with Mobility Control Info OR at the receipt of mobility from EUTRA command message including CELL CHANGE ORDER	Criterion for successful completion of handover to EUTRA or cell Change order is met (the criterion is specifiedin the target RAT incase of inter-RAT)	In case of cell change order from E-UTRA or intra E-UTRA handover,initiate theRRCconnectionreestablishment procedure; Incase of handover toEUTRA, perform the actions defined in thespecificationsapplicable forthe source RAT	For EUTRAN: 500ms for GERAN: 8000ms
T305	Access barred while performing RRCconnectionestablishment for mobile originating signalling	Upon entering RRC_CONNECTEDand upon cell re-selection	Informs upper Layers
T310	Upon detecting physical layer problemsi.e. upon receiving N310 consecutiveout-of-sync indications from lowerlayers	Upon receiving N311 consecutive in-sync indications from lower layers,upon triggering the handover procedure and upon initiating the connection re-establishment procedure	the UE enters the RRC_IDLE mode if the security mode is not activated. If the security mode is activated, the UE initiates an RRC connection reestablishment procedure.	1000ms
T311	Upon initiating the RRC connection re-establishment procedure	the UE selects an E-UTRAN or inter-RAT cell to camp on.	the UE enters the RRC_IDLE mode	1000ms
T320	Upon receiving t320 or upon cell (re)selection to E-UTRA from another RAT with validity time configured for dedicated priorities (in which case the remaining validity time is applied)	Upon entering RRC_CONNECTED,when PLMN selection is performed on request by NAS, or upon cell (re)selection to another RAT (in which case the timer is carried on to the other RAT)	Discard the cell reselection priority information provided by dedicated signaling
T321	starts upon receipt of measConfig including a reportConfig with the purpose set to reportCGI	Stops at either of following cases: 1. Upon acquiring the information needed to set all fields of Global CellId for the requested cell 2. upon receipt of measConfig that includes removal of the reportConfig with the purpose set to reportCGI	At expiry initiates the measurement reporting procedure, stop performing the related measurements and remove the corresponding measID