Methods for updating timing advance and beam and bandwidth part switching for non-terrestrial networks

A method of performing a timing advance adjustment between a user equipment (UE) and a non-terrestrial network (NTN), the method comprising:

• receiving and decoding a medium access control (MAC) control element (CE) including closed loop information;
• receiving and decoding system information including open loop information;
• determining a timing advance value based on either the closed loop information or the open loop information;
• and
• controlling timing of an uplink transmission signal, transmitted from the UE, based on the timing advance value,
• wherein determining the timing advance value comprises:
• configuring a priority timer,
• assigning a priority to either a closed loop method or an open loop method, and
• using either the closed loop method or the open loop method to determine the timing advance value based on the assigned priority and a state of the priority timer.