Patent ID: 9565703
Date: 2017-02-07
CPC Classifications: H04L,H04W

Claim:
1. A method of performing a random access procedure by a terminal in wireless communication system, the method comprising: receiving, at the terminal, a time advance command (TAC) for operating a time alignment timer (TAT) that is used to control how long the terminal is considered uplink time aligned, wherein the TAC is received in a random access response message; determining, at the terminal, whether a random access preamble to be used by the terminal in the random access procedure was not selected by the terminal; and if it is determined that the random access preamble was not selected by the terminal, applying the TAC, and starting or restarting the TAT; if it is determined that the random access preamble was selected by the terminal and if the TAT is not running, applying the TAC, starting the TAT, and stopping the TAT when a contention resolution is considered not successful; and if it is determined that the random access preamble was selected by the terminal and if the TAT is running, ignoring the received TAC.