Hello All.
What is the recommended value of Inactivity Timer in a LTE cell?
(brings out popcorn)
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Vendor document mentions the recommended value.
I’ve mostly seen 20ms but some of the high volume cells also had 10ms.
The inactivity timer that I know is usually between 30-60 seconds.
This is the LTE inactivity timer that release the access bearers and requires signaling to set them up again.
You have to be careful with lower value like 10ms, a large number of RRC connection requests could also congest PUCCH.
Actually it is configured as 10 ms in our network.
We observe too many context release due to inactivity timer.
Yes that would happen.
You can check the vendor’s recommended value from the CPI.
Smaller value usually also improves call drop rate but at the same time in high traffic areas, it can degrade the setup success rate.
It can’t be in ms. Must be in second.
10 seconds.
Anything between 2 sec to 10 sec.
30-60 seems like very large numbers.
I have seen around 10sec I guess.
It is generally 10 seconds, but there are features in Nokia which can adaptively select a lower value based on device traffic profile.
Yes you’re right, it’s in seconds not millisecond. 
Can you please tell some feature for this?
Data session profile
I suppose the inactivity timer you mentioned should be a timer used in MME? when the timer timeout, MME will consider the UE is not reachable and it will release corresponding UEcontext, which means the UE will be EMM_DEREGISTER state, which also means MME don’t have any the UE context.
Usually the inactive timer in MME should be larger than periodic TAU update timer, because the inactive timer in MME will be reset after receiving the TAU update message.
Different vendors have their own optimized paramter, you can refer to their CPI to get the value.
Qustion is not very specific therefore I will give you the minimum inactivity timer value in a network and maximum one related to UE.Minimum one I could think of is the Idle Mode timer .In technical terms T3412(Periodic Tracking Area Ipdate timer) usually between 30-60 seconds and set in MME .This is the timer where UE goes from connected mode to idle mode.Maximum one I can think of is SIP contact expiery timer which can be set in PCSCF.This is the timer where UE will do a re-registraion towards IMS adn Usually network set this to values like 7200S(2 hours) or 3600(1 hour) to avoide un necessory signalling lode in IMS.