LTE EPS mobility management timers - EMM timers

Lately many times I had to reach towards the EPS Mobility Management (EMM) timers, because it took me some time to google them here you go. Hope any one will find them as useful I did. 

In the two tables you can easily find the times name it's default or suggested value, what is triggering it and what happens in case it will finally expire.

EPS mobility management timers – UE side

TIMER NUM.	TIMER VALUE	STATE	CAUSE OF START	NORMAL STOP	ON EXPIRY
T3402	Default 12 min. NOTE 1	EMM-DEREGISTERED EMM-REGISTERED	At attach failure and the attempt counter is equal to 5. At tracking area updating failure and the attempt counter is equal to 5.	ATTACH REQUEST sent TRACKING AREA UPDATE REQUEST sent	Initiation of the attach procedure or TAU procedure
T3410	15s	EMM-REGISTERED-INITIATED	ATTACH REQUEST sent	ATTACH ACCEPT received ATTACH REJECT received	Start T3411 or T3402 as described in subclause 5.5.1.2.6
T3411	10s	EMM-DEREGISTERED. ATTEMPTING-TO-ATTACH EMM-REGISTERED. ATTEMPTING-TO-UPDATE	At attach failure due to lower layer failure, T3410 timeout or attach rejected with other EMM cause values than those treated in subclause 5.5.1.2.5. At tracking area updating failure due to lower layer failure, T3430 timeout or TAU rejected with other EMM cause values than those treated in subclause 5.5.3.2.5.	ATTACH REQUEST sent TRACKING AREA UPDATE REQUEST sent	Retransmission of the ATTACH REQUEST or TRACKING AREA UPDATE REQUEST
T3412	Default 54 min. NOTE 2 NOTE 5	EMM-REGISTERED	In EMM-REGISTERED, when EMM-CONNECTED mode is left.	When entering state EMM-DEREGISTERED or when entering EMM-CONNECTED mode.	Initiation of the periodic TAU procedure if the UE is not attached for emergency bearer services. Implicit detach from network if the UE is attached for emergency bearer services.
T3416	30s	EMM-REGISTERED-INITIATED EMM-REGISTERED EMM-DEREGISTERED-INITIATED EMM-TRACKING-AREA-UPDATING-INITIATED EMM-SERVICE-REQUEST-INITIATED	RAND and RES stored as a result of a UMTS authentication challenge	SECURITY MODE COMMAND received SERVICE REJECT received TRACKING AREA UPDATE ACCEPT received AUTHENTICATION REJECT received AUTHENTICATION FAILURE sent EMM-DEREGISTERED or EMM-NULL entered	Delete the stored RAND and RES
T3417	5s	EMM-SERVICE-REQUEST-INITIATED	SERVICE REQUEST sent EXTENDED SERVICE REQUEST sent in case f, g, i and j in subclause 5.6.1.1	Bearers have been set up SERVICE REJECT received	Abort the procedure
T3417ext	10s	EMM-SERVICE-REQUEST-INITIATED	EXTENDED SERVICE REQUEST sent in case d in subclause 5.6.1.1 EXTENDED SERVICE REQUEST sent in case e in subclause 5.6.1.1 and the CSFB response was set to "CS fallback accepted by the UE"	Inter-system change from S1 mode to A/Gb mode or Iu mode is completed Inter-system change from S1 mode to A/Gb mode or Iu mode is failed SERVICE REJECT received	Abort the procedure
T3418	20s	EMM-REGISTERED-INITIATED EMM-REGISTERED EMM-TRACKING-AREA-UPDATING-INITIATED EMM-DEREGISTERED-INITIATED EMM-SERVICE-REQUEST-INITIATED	AUTHENTICATION FAILURE (EMM cause = #20 "MAC failure" or #26 "non-EPS authentication unacceptable") sent	AUTHENTICATION REQUEST received	On first expiry, the UE should consider the network as false and follow item f of subclause 5.4.2.7, if the UE is not attached for emergency bearer services. On first expiry, the UE will follow subclause 5.4.2.7 under “For items c, d, and e:”, if the UE is attached for emergency bearer services.
T3420	15s	EMM-REGISTERED-INITIATED EMM-REGISTERED EMM-DEREGISTERED-INITIATED EMM-TRACKING-AREA-UPDATING-INITIATED EMM-SERVICE-REQUEST-INITIATED	AUTHENTICATION FAILURE (cause = #21 "synch failure") sent	AUTHENTICATION REQUEST received	On first expiry, the UE should consider the network as false and follow item f of subclause 5.4.2.7, if the UE is not attached for emergency bearer services. On first expiry, the UE will follow subclause 5.4.2.7 under “For items c, d, and e:”, if the UE is attached for emergency bearer services.
T3421	15s	EMM-DEREGISTERED-INITIATED	DETACH REQUEST sent	DETACH ACCEPT received	Retransmission of DETACH REQUEST
T3423	NOTE 3	EMM-REGISTERED	T3412 expires while the UE is in EMM-REGISTERED.NO-CELL-AVAILABLE and ISR is activated.	When entering state EMM-DEREGISTERED or when entering EMM-CONNECTED mode.	Set TIN to "P‑TMSI"
T3430	15s	EMM-TRACKING-AREA-UPDATING-INITIATED	TRACKING AREA UPDATE REQUEST sent	TRACKING AREA UPDATE ACCEPT received TRACKING AREA UPDATE REJECT received	Start T3411 or T3402 as described in subclause 5.5.3.2.6
T3440	10s	EMM-REGISTERED-INITIATED EMM-TRACKING-AREA-UPDATING-INITIATED EMM-DEREGISTERED-INITIATED EMM-SERVICE-REQUEST-INITIATED EMM-REGISTERED	ATTACH REJECT, DETACH REQUEST, TRACKING AREA UPDATE REJECT with any of the EMM cause #11, #12, #13, #14 or #15 SERVICE REJECT received with any of the EMM cause #11, #12, #13 or #15 TRACKING AREA UPDATE ACCEPT received after the UE sent TRACKING AREA UPDATE REQUEST in EMM-IDLE mode with no "active" flag	Signalling connection released Bearers have been set up	Release the signalling connection and proceed as described in subclause 5.3.1.2
T3442	NOTE 4	EMM-REGISTERED	SERVICE REJECT received with EMM cause #39 "CS domain temporarily not available"	TRACKING AREA UPDATE REQUEST sent	None
NOTE 1: The default value of this timer is used if the network does not indicate another value in an EMM signalling procedure. NOTE 2: The value of this timer is provided by the network operator during the attach and tracking area updating procedures. NOTE 3: The value of this timer may be provided by the network in the ATTACH ACCEPT message and TRACKING AREA UPDATE ACCEPT message. The default value of this timer is identical to the value of T3412. NOTE 4: The value of this timer is provided by the network operator when a service request for CS fallback is rejected by the network with EMM cause #39 "CS domain temporarily not available". NOTE 5: The default value of this timer is used if the network does not indicate a value in the TRACKING AREA UPDATE ACCEPT message and the UE does not have a stored value for this timer.

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 if the UE is not attached for emergency bearer services. Implicitly detach the UE which is attached for emergency bearer services.
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.

Source:

TS 23.401 3GPP