RAB establishment fai due to Cell reselection

[nhake]

Dear Expert

I found a case that RAB establishment fail as describe below:
- UE already active PDP context and in Cell_FACH state
- UE received CS call and signalling procedures take place.
During exchange signalling : UE performe CELL_UPDATE with cause cellReselection and receive CELL_UPDATE_CONFIRM. At the time RNC send CELL_UPDATE_CONFIRM, RNC receive RAB_ASSIGNMENT_REQUEST require establish CS RAB. Immidiately, RNC send RAB_ASSIGNMENT_RESPONSE with the failure cause "release-due-to-utran-generated-reason". So CS call attempt fail

i think there is collision between Cell_Update and RAB establishment in RNC
Do you have any explanation in this case?

P/S: E******* vendor

[webkasperl]

That's a bad E/// SW limitation and smartphone users in mobility suffer from this
Maybe new SW version will bring improvement???