In LTE handover procedure, after UE handover to the target cell, if new TAI is not in the TAI list, the TAU will be triggered.
In HO procedure, UL/DL data has been handover to the target cell.
But before TAU, the UE doesn't register to the new MME, in the new cell, how the the DL/UL data transfer between UE and network(S-GW / P-GW) before TAU and after HO.
Also, as we know, if the TAU fails, the DL/UL data transfer will be interrupted, which network element will release the DL/UL throughput?
