What is the meaning of Release Cause - Release due to E-UTRAN generated reason?

4G LTE
1

Hi All,
Can anyone tell me in LTE S1 UE Context Release Request (ENB > MME) message what is the meaning of Release Cause - Release due to E-Utran generated reason?
What are the scenario when eNB can send this message?

2

This release is due to timer TX2RELOCOverall Expiry.
Mainly poor coverage, overshooting cell, HO failures, re-establishment failure, etc.

3

Thank you for the response @Ameen.
As I know, if these realease cause is present in the S1 UE context Release Command message (MME to eNB) then generally the reasons at eNB side are mention by you as above.
eNB sent req message and in response MME send the command message.

However when eNB send the same release cause in UE context release req, is it due to the same reasons?

4

You can check the UE context release req message details for cause value.
You can find it there, values like User inactivity, RC lost with UE, subscription expiry, etc.
Many more cause values.
By this you can find the reason.
For RC lost with UE and user inactivity are most seem cause values which are due to the above reasons.

5

Actually I got “Release due to E-UTRAN Generated Reason” in S1 UE context release Request message only (eNB>MME).
Both release req and release command has same release cause value - “Release due to E-UTRAN Generated Reason”.
And it is not for single call, there are many drops like this in the network.:roll_eyes:

6

Consult the vendor.
This is very generic cause to be used by eNB. It is typically used by MME to refer to radio related issue because MME does not have clear picture about radio side. ENB should use a more specifc cause from the 3GPP list

7

Hi Ameen…in our NW we have S1AP:UE CONTEXT RELEASE REQUEST message sent by the eNB to the MME with the RNL cause as “Inter-RAT redirection” and in other cases “CS Fallback Triggered”.

That means iRNL cause can be redirection/CSFB. My question is that ERAB is already established so RNL should trigger SRVCC, no ? Why a redirection or csfb ? since simply put…csfb is service HO while SRVCC is coverage HO. So if UE has a QCi1 ERAB and it is lost, then why not a SRVCC ?