Patent ID: 8514757

Claim:
A base station (BS) for communicating with a mobile station (MS) in a wireless access system, the BS comprising: a processor configured to: receive a first ranging request (RNG-REQ) message from the MS, transmit a first ranging response (RNG-RSP) message to the MS in response to the first RNG-REQ, wherein the first RNG-RSP message comprises a first periodic ranging frame offset, allocate a first uplink bandwidth (UL-BW) when a first time indicated by the first periodic ranging frame offset is reached, wherein the first UL-BW is allocated for a second RNG-REQ message to be transmitted by the MS, receive the second RNG-REQ message from the MS through the first UL-BW, transmit a second RNG-RSP message in response to the second RNG-REQ message to the MS, wherein the second RNG-RSP message comprises a second periodic ranging frame offset, allocate a second UL-BW when a second time indicated by the second periodic ranging frame offset is reached, wherein the second UL-BW is allocated for a third RNG-REQ message to be transmitted by the MS, and receive the third RNG-REQ message from the MS through the second UL-BW.