User equipment and base station involved in a handover

Abstract

The present disclosure relates to a user equipment (UE) that comprises a receiver of the UE receives, from a source base station of a source radio cell, a common timing advance value for a target radio cell. The UE is connected to the source radio cell and is involved in a handover procedure to hand over the UE from the source radio cell to the target radio cell. Further, the common timing advance value is received from the source base station in a first message of the handover procedure, which also comprises a timing indication for transmitting a second message from the UE to the target base station. Then, a processor of the UE determines a first uplink timing of uplink transmissions to the target base station with respect to downlink transmissions from the target base station, based on the received common timing advance value and the timing indication. A transmitter of the UE transmits a second message of the handover procedure to the target base station based on the determined uplink timing. The processor determines a UE-specific timing advance value, specific to the UE and the target radio cell, to be used by the UE for performing uplink transmissions in the target radio cell.