Patent ID: 6215811
Filing Date: 2001-04-10
Classification: H04B,H04W

Abstract:
In a spread-spectrum-communications system having a plurality of base stations and a remote unit, with the remote unit communicating with a first base station using spread-spectrum modulation, with the remote unit despreading a first received-spread-spectrum signal transmitted from the first base station, and with the remote unit transmitting data to the first base station at a first data rate and a first power level, a method comprising the steps of:monitoring, at said remote unit, a first signal quality of the first received-spread-spectrum signal;scanning, at said remote unit, a plurality of received-spread-spectrum signals radiated from the plurality of base stations, respectively;storing, at said remote unit, a plurality of signal qualities for the plurality of received-spread-spectrum signals, respectively;selecting, from the plurality of received-spread-spectrum signals, at said remote unit, using the plurality of signal qualities from the plurality of received-spread-spectrum signals, a second received-spread-spectrum signal having a second signal quality transmitted from a second base station;determining when the first signal quality falls below any of a predetermined handoff threshold and the second signal quality;initiating, from said remote unit, upon the first signal quality falling below any of the predetermined handoff threshold and the second signal quality, handoff to the second base station;queuing, upon requesting handoff to the second base station, data for transmission at said remote unit;storing the queued data;synchronizing, at said remote unit, to the second received-spread-spectrum signal and handing off from said first base station to said second base station; andtransmitting, from said remote unit to said second base station, the stored data at a second data rate, with the second data rate greater than the first data rate, thereby transferring the stored data to said second base station.