Patent ID: 8929305
Filing Date: 2015-01-06
Classification: H04L,H04W

Abstract:
1. A method of a mobile station for performing ranging in a broadband wireless access system, the method comprising: transmitting a first ranging preamble code for a ranging procedure to a base station through a first ranging opportunity of a first frame; and determining whether or not the ranging procedure is successful based on at least one of a timer indicating a time limit, a first message transmitted by the base station, and uplink resource allocation information for transmitting a second message to the base station, wherein the first message comprises a frame index indicating a frame containing ranging opportunities to which the first message refers, a bitmap indicating a decoding status of the ranging opportunities in the frame indicated by the frame index, and at least one index of a ranging preamble code decoded successfully from the ranging opportunities, wherein if the first message has been received from the base station before the timer expires but the at least one index of the ranging preamble code included in the first message does not correspond to the first ranging preamble code transmitted by the mobile station, the ranging procedure is determined to be failed, and wherein if the uplink resource allocation information has been received solely without receiving the first message before the timer expires, the ranging procedure is determined to be successful.