US Patent 8976780 Uplink timing maintenance upon time alignment timer expiry

Systems, apparatuses, and methods for uplink timing maintenance in wireless communications are provided. Certain aspects of the disclosure involve, at a user equipment (UE), detecting a downlink transmission timing has changed by an amount of time. The UE may determine that a time alignment timer (TAT) is not running or determine the downlink transmission timing change is not compensated for. The UE can adjust a timing advance based on the amount of time that the downlink transmission timing has changed.