Hi Experts.
If UE is Voice centric, VoLTE is disabled and CSFB by eNB is not activated.
Can that scenario could be an problem for UE data transfer?
As long as UE gets Combined Attach Accept, there shall be no issue with data.
And one more. Is there a possibility that UE initiate detach in order to find a network that supports Voice?
If UE gets Attach Accept with:
- #18 would make it to search for other RAT
- #16 would make it to retry TAU 5 times
- #17 after 5 attempts may move UE to lower RAT, then to another PLMN
If you’re looking for UE initiated Detach and try on other PLMN, that needs multiple EHPLMN/PPLMN and NW sending EPS only attach.
I see one log file, it describe eNB disable CSFB.
When UE request CSFB, not RRC-release to UMTS, but 10s later UE will automaticly search and request CS service in UMTS.
Do you mean on emm cause?
Yes, MM can cause UE to move away from this PLMN/Tracking area or RAT.
Autonomously UE cannot move away.
Ok, but no other RATs awailable in this scenario.
Only 4G test cell in the lab.
Ok I see, it will try another Rat. But what if no other RAT? 
Data centric UE will attach to EPS domain only, not combined attach to CS donain, right?
Yes, exactly right, for this case.
In that case will search for other PLMN.