A user equipment (UE) receives a timing advance medium access control (MAC) control element. The UE applies a timing advance command of the timing advance MAC control element and to start or restart a time alignment timer. The UE releases physical uplink control channel (PUCCH) resources and releases any assignment sounding reference signal (SRS) resources, when the time alignment timer expires. The UE flushes hybrid automatic request (HARQ) buffers, when the time alignment timer expires or is stopped.