LTE: When does an eNodeB issues RRC Connection Release message towards an UE ?

Question

I saw RRC Connection Reject message in specification. There is an IE "deprioritisationReq" within the RRCConnectionReject message. I want to know when eNodeB includes this IE while rejecting a rrc connection request for an UE.

Answer 1

There are several reasons for an RRC connection releases to be sent by the eNB to the UE. Among them:

1) Expiration of the inactivity time( about 10 secs)
2) As a result of a drop call of some sort
3) In case of a tracking area update
4) During a Detach

Comments

In addition to Avigdor's answer -
RRC connection is also released is case of CS fallback.

Answer 2

Following are the reasons:

• Expiration of the inactivity timer
• RLF observed at eNB
• loadBalancingTAU required
• Detach Procedure
• UE initiated/terminated CS-Fallback