Gradual timing adjustment for wireless devices in a non-terrestrial network

An apparatus, comprising one or more processors and memory configured to cause a wireless device to:

• detect a trigger for changing a gradual timing adjustment rate for a non-terrestrial network (NTN) based wireless link with a cellular base station from a first gradual timing adjustment rate to a second gradual timing adjustment rate;
• determine a time window for which to perform gradual timing adjustment at the second gradual timing adjustment rate, wherein the time window for which to perform gradual timing adjustment at the second gradual timing adjustment rate is determined based at least in part on an accumulated amount of gradual timing adjustment or closed-loop timing advance implemented by the wireless device after the trigger for changing the gradual timing adjustment rate;
• and
• perform gradual timing adjustment at the second gradual timing adjustment rate for the time window.

A cellular base station, comprising:

• one or more processors;
• and
• a memory having instructions stored thereon, which when executed by the one or more processors, cause the cellular base station to:
• establish a non-terrestrial network (NTN) based wireless link with a wireless device;
• and
• provide an indication to the wireless device to change, for the NTN based wireless link and during a time window for which to perform the gradual timing adjustment at a second gradual timing adjustment rate, a gradual timing adjustment rate from a first gradual timing adjustment rate to the second gradual timing adjustment rate, wherein the time window for which to perform the gradual timing adjustment at the second gradual timing adjustment rate is based at least in part on an accumulated amount of gradual timing adjustment or closed-loop timing advance implemented by the wireless device after the indication for changing the gradual timing adjustment rate.