4G/LTE - Timers

 

 

 

 

Timer (EPS Mobile Management - NW Side)

 

Following table comes from 24.301 - 10.2 Timers of EPS mobility management (Table 10.2.2: EPS mobility management timers – Network side)

TIMER
NUM.
TIMER
VALUE
STATE CAUSE OF START NORMAL STOP ON THE
1st, 2nd, 3rd, 4th
EXPIRY (NOTE 1)
T3413 NOTE 2 EMM REGISTERED Paging procedure for EPS services initiated Paging procedure for EPS services completed Network dependent
T3422 6s EMM DEREGISTERED INITIATED DETACH REQUEST sent DETACH ACCEPT received Retransmission of DETACH REQUEST
T3450 6s EMM-COMMON PROC-INIT ATTACH ACCEPT sent
TRACKING AREA UPDATE ACCEPT sent with GUTI
TRACKING AREA UPDATE ACCEPT sent with TMSI
GUTI REALLOCATION COMMAND sent
ATTACH COMPLETE received
TRACKING AREA UPDATE COMPLETE received
GUTI REALLOCATION COMPLETE received
Retransmission of the same message type, i.e. ATTACH ACCEPT,TRACKING AREA UPDATE ACCEPT or GUTI REALLOCATION COMMAND
T3460 6s EMM-COMMON PROC-INIT AUTHENTICATION REQUEST sent
SECURITY MODE COMMAND sent
AUTHENTICATION RESPONSE received
AUTHENTICATION FAILURE received
SECURITY MODE COMPLETE received
SECURITY MODE REJECT received
Retransmission of the same message type, i.e.AUTHENTICATION REQUEST or SECURITY MODE COMMAND
T3470 6s EMM-COMMON PROC-INIT IDENTITY REQUEST sent IDENTITY RESPONSE received Retransmission of IDENTITY REQUEST
Mobile
reachable
Default 4 min greater than T3412 All except EMM DEREGISTERED Entering EMM-IDLE mode NAS signalling connection established Network dependent, but typically paging is halted on 1st expiry
Implicit
detach
timer
NOTE 3 All except EMM DEREGISTERED The mobile reachable timer
expires while the network is in
EMM-IDLE mode
NAS signalling connection established Implicitly detach the UE on 1st expiry
           
NOTE 1: Typically, the procedures are aborted on the fifth expiry of the relevant timer. Exceptions are described in the corresponding procedure description.
NOTE 2: The value of this timer is network dependent.
NOTE 3: The value of this timer is network dependent. If ISR is activated, the default value of this timer is 4 minutes greater than T3423.