Type of early timing advance acquisition

Abstract

A wireless device receives, from a base station, a radio resource control (RRC) reconfiguration message comprising a layer 1 and/or layer 2 triggered mobility (LTM) configuration of the wireless device. The LTM configuration comprises a configuration of a candidate cell for an LTM, a first identifier of the candidate cell, and a second identifier of the candidate cell for an early timing advance acquisition (ETA). The ETA comprises a user equipment (UE) based timing advance (TA) measurement. The wireless device measures a TA value of the candidate cell based on the RRC reconfiguration message comprising the second identifier. The wireless device receives an LTM cell switch command indicating the candidate cell. In response to receiving the LTM cell switch command, the wireless device transmits, via the candidate cell and based on the TA value, an uplink packet.