Patent ID: 7864727

Claim:
A congestion control method for a wireless communication system having a plurality of base stations for performing code division multiple access (CDMA) wireless communication and a base station control apparatus for controlling the plurality of base stations, the congestion control method comprising the steps of: the base station control apparatus determining whether a sector is in a light congestion state or a heavy congestion state in accordance with at least two different congestion levels, with reference to a wireless resource usage amount data base having stored a wireless resource usage amount for each sector, based on the wireless resource usage amount; (1) if a sector is determined to be in the light congestion state, the base station control apparatus referencing a neighbor list database having stored, on a sector basis, a neighbor sector and a neighbor search window size indicating the size of an area or the number of chips by which a wireless terminal searches for the neighbor sector, and the wireless resource usage amount database; extracting a sector which has specified the congested sector as a neighbor sector and is not congested itself; and reducing the neighbor search window size of the congested sector with respect to the data of the extracted sector in the neighbor list database to suppress a soft hand-over from the extracted sector to the congested sector; and (2) if a sector is determined to be in the heavy congestion state, the base station control apparatus referencing a radio wave capture state database having stored time-series data of a radio wave capture state of each wireless terminal on a sector basis and the wireless resource usage amount database; extracting a wireless terminal which specifies the congested sector as a neighbor sector and keeps capturing radio waves of a plurality of sectors for a predetermined period of time or longer and sectors serving the wireless terminal; and selecting a sector having a relatively small wireless resource usage amount, from the extracted sectors, and causing forced soft hand-over of the wireless terminal to the selected sector.