Method and apparatus for timer handling in conditional mobility in a wireless communication system

A User Equipment (UE), comprising:

• a memory;
• and
• a processor operatively coupled with the memory, wherein the processor is configured to execute a program code to:
• receive a configuration of at least one candidate cell including a first candidate cell;
• start or restart a first timer, for time alignment, associated with the first candidate cell in response to receiving a Medium Access Control (MAC) Control Element (CE) indicating a Timing Advance (TA) associated with the first candidate cell;
• and
• if the UE determines to initiate a conditional Layer 1 (L1)/Layer 2 (L2) Triggered Mobility (LTM) Cell switch on the first candidate cell, the UE starts a timeAlignmentTimer with a value based on remaining time of the first timer associated with the first candidate cell, wherein the timeAlignmentTimer is associated with a Timing Advance Group (TAG) of the first candidate cell and controls how long a MAC entity considers Serving Cells to the TAG to be uplink time aligned for the TAG.