EPC: S1 release (not implemented)

The S1 release procedure for user inactivity is currently a not implmeneted feature.

When a UE is idle for a certain period of time (usually 10-30 seconds in commercial networks), after the RRC inactivity timer times out, the eNodeB will send a UE Context Release Request with cause #20 (closed) (user inactivity) to the EPC.

user inactivity is the most common cause for S1 release, but it can happen due to:

eNB triggered:

• repeated RRC signaling integrity check failure
• release due to UE generated signaling connection release
• unspecified failure
• O&M intervention

MME triggered:

• authentication failure
• detach
• disallowed CSG cell

More detailed information of S1 release procedure can be found here:

http://www.netmanias.com/en/post/techdocs/6110/emm-lte/emm-procedure-3-s1-release

Related issues:

• RRC inactivity timer is not implemented in the OAI eNodeB
• Service request handling is not implemented in OAI EPC