Patent ID: 6535494
Filing Date: 2003-03-18
Classification: H04B,H04W

Abstract:
A code division multiple access (CDMA) mobile telecommunication method for a CDMA mobile telecommunication system wherein a plurality of radio base stations are disposed under one base control station and a control channel signal and a traffic channel signal from said base control station are communicated between said radio base stations and a mobile station, comprising:transmitting, when a call is to be connected, an origination signal or a page response signal to which signal strength information of an adjacent cell is added from said mobile station to a particular one of said radio base stations which exhibits the highest signal strength; transmitting, when said base control station receives the origination signal or page response signal from said mobile station through the particular radio base station, control channel information used by the particular radio base station from said base control station to a radio base station of the adjacent cell if said base control station discriminates from the signal strength information of the adjacent cell included in the origination signal or page response signal that said mobile station is present in a boundary region of the adjacent cell; starting, when the radio base station of the adjacent cell receives the control channel information from said base control station, communication of the control channel by the radio base station of the adjacent cell in accordance with the control channel information; transmitting, when said base control station is to transmit a descending control channel signal to said mobile station, the descending control channel signal from said base control station to the particular radio base station and the adjacent radio base station; transmitting, when each of the particular radio base station and the radio base station of the adjacent cell receives an ascending control channel signal from said mobile station, the ascending control channel signal with a signal quality of the received ascending control channel signal added to the ascending control channel signal from the radio base station and the radio base station of the adjacent cell to said base control station; selecting, by said base control station, one of the ascending control channel signals received through the particular radio base station and the radio base station of the adjacent cell based on the signal qualities of the ascending control channel signals, and wherein said mobile station, said particular radio base station, and said radio base station of the adjacent cell enter a soft hand-off state on a control channel selected by said base control station, said particular radio base station and said radio base station of the adjacent cell starting up a traffic channel for voice communication by said mobile station while in said soft hand-off state.