Methods and apparatus for timing synchronization during a wireless uplink random access procedure

摘要

Aspects generally relate to wireless communications and, more particularly, to methods, systems and apparatus for timing synchronization during a wireless uplink random access procedure. For example, certain aspects relate to a technique for receiving first timing advance information associated with uplink wireless communications with a base station (BS), transmitting a random access connection request message to the BS, receiving a random access response from the BS while the first timing advance information is within a valid time period, the random access response comprising second timing advance information associated with uplink wireless communications with the base station, determining, after receiving the random access response, that the valid time period for the first timing advance information has expired, and utilizing the second timing advance information for uplink communications with the BS after determining that the valid time period for the first timing advance information has expired. Numerous other aspects are provided.

主权项

1. A method of wireless communication by a user equipment (UE), comprising:
receiving first timing advance information associated with uplink wireless communications with a base station (BS); initiating a first timer associated with the first timing advance information to measure a valid time period for the first timing advance information; transmitting a random access connection request message to the BS; receiving a random access response from the BS while the first timing advance information is within the valid time period for the first timing advance information, the random access response comprising second timing advance information associated with uplink wireless communications with the BS; transmitting a radio resource control (RRC) connection request to the BS after receiving the random access response; receiving a contention resolution response from the BS responsive to the RRC connection request; determining, after receiving the contention resolution response, that the valid time period for the first timing advance information has expired; utilizing the second timing advance information for uplink communications with the BS after determining that the valid time period for the first timing advance information has expired; initiating a second timer, different from the first timer, associated with the second timing advance information for a valid time period for the second timing advance information after determining that the valid time period for the first timing advance information has expired; and adjusting an expiration of the second timer based on an elapsed time between the receipt of the random access response and the expiration of the valid time period for the first timing advance information.