Friday, November 11, 2011

LTE Timers

Timer Start Stop At expiry
T300 Transmission of RRCConnectionRequest Reception of RRCConnectionSetup or RRCConnectionReject message, cell re-selection and upon abortion of connection establishment by upper layers Perform the actions
T301 Transmission of RRCConnectionReestabilshmentRequest Reception of RRCConnectionReestablishment or RRCConnectionReestablishmentReject message as well as when the selected cell becomes unsuitable Go to RRC_IDLE
T303 Access barred while performing RRC connection establishment for mobile originating calls Upon entering RRC_CONNECTED and upon cell re-selection Inform upper layers about barring alleviation as specified
T304 Reception of RRCConnectionReconfiguration message including the MobilityControl Info or reception of MobilityFromEUTRACommand message including CellChangeOrder Criterion for successful completion of handover to EUTRA or cell change order is met (the criterion is specified in the target RAT in case of inter-RAT) In case of cell change order from E-UTRA or intra E-UTRA handover, initiate the RRC connection re-establishment procedure; In case of handover to E-UTRA, perform the actions defined in the specifications applicable for the source RAT.
T305 Access barred while performing RRC connection establishment for mobile originating signalling Upon entering RRC_CONNECTED and upon cell re-selection Inform upper layers about barring alleviation as specified
T310 Upon detecting physical layer problems i.e. upon receiving N310 consecutive out-of-sync indications from lower layers Upon receiving N311 consecutive in-sync indications from lower layers, upon triggering the handover procedure and upon initiating the connection re-establishment procedure If security is not activated: go to RRC_IDLE else: initiate the connection re-establishment procedure
T311 Upon initiating the RRC connection re-establishment procedure Selection of a suitable E-UTRA cell or a cell using another RAT. Enter RRC_IDLE
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 signalling.
T321 Upon receiving measConfig including a reportConfig with the purpose set to reportCGI Upon acquiring the information needed to set all fields of globalCellId for the requested cell, upon receiving measConfig that includes removal of the reportConfig with the purpose set to reportCGI Initiate the measurement reporting procedure, stop performing the related measurements and remove the corresponding measId