For LTE, when t3402 timer come into picture?

4G LTE
1

Hi Experts.
For LTE, when t3402 timer come into picture?

2

When deregistered for 5 consecutive attach failures.

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image1287×514 150 KB

https://www.sharetechnote.com/html/Handbook_LTE_Timer_EPS_UE.html

3

Is it tx from network to UE?
I mean timer value?

4

Is sent by NW in attach accept.
Usually is 12 minutes.

5

This looks like MME own internal timer. Not something sent to UE.

6

Nope. This is sent to UE in TAU/attach accept.
This is used as a plmn/ta backoff mechanism at UE when failure count reaches 5.
If not sent, Default value is 12min.

7

Right. Sorry.
Yes: You are are correct! :wink:

8

After 5 MM attempts, 5 times attach/tau/service request gets some failures, UE starts T3402 and disabled S1 mode for 12 mins (if no other configured).