How to inform MME about UE movement from eNB1 to eNB2 after UE sending Re-establishment-HO failure to eNB2 during HO?

Question

How to inform MME about UE movement from Source eNB to Target eNB after UE sending Re-establishment with HO failure to target eNB during handover. In this case HO notify or path switch is applicable ?

Answer 1

In Case of X2 handover, target eNodeB sends PATH switch request to MME, while in case of S1-AP handover since MME is already aware about ongoing handover singalling, target eNodeB confirms handover by using "HO notify" message to MME.
Please correct me if I am wrong.

Answer 2

Hi,
As far as I know,Handover failure occurs when UE is trying to do rach to the target cell but failed may be because of sync failure or exceeded preambleTransMax,In which case UE sends reestablishment to the target cell with HO-failure cause.
Path switch request(in case of X2-hanover) and Handover notify (in case of S1AP handover) will go to MME only when target ENB receives the reconfiguration complete message from UE and to send reconfiguration complete message UE will do contention free RACH.
So, Unless UE sends Reconfiguration complete to target cell there is no point to mention about the UE movement to the MME.