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 ?