Radio communication system and base station

Abstract

A radio communication system includes a grouping unit for grouping a plurality of base stations into a plurality of groups (Soft Handoff Groups) and a determining unit for selecting base stations belonging to one and the same group selected from the groups produced by the grouping unit and for determining the base stations as base stations to send communication packets to an access terminal.

1 . A radio communication system including access terminals and a plurality of base stations communicable with the access terminals, comprising: 
 grouping means for grouping the base stations into a plurality of groups in association with Soft Handoff; and    a determining unit for selecting, from the base stations, base stations belonging to one of the groups produced by the grouping means, and for determining the base stations as base stations which send communication packets to the access terminal.    
   
   
       2 . A radio communication system including access terminals and a plurality of base stations communicable with the access terminals, comprising: 
 a calculating unit for calculating distance between the access terminal and a first base station selected from the base stations, according to respective positional information of the access terminal and the first base station;    a comparing unit for comparing a calculated result calculated by the calculating unit with a predetermined parameter (Soft Combine Radius (SCR)); and    a requesting unit for requesting, according to a result of the comparison by the comparing unit, a second base station selected from the base stations to send a communication packet to the access terminal.    
   
   
       3 . A radio communication system according to  claim 2 , wherein the requesting unit requests the second base station selected from the base stations to send a communication packet to the access terminal if the calculated result from the calculating unit is more than a value of the parameter.  
   
   
       4 . A radio communication system according to  claim 3 , wherein the requesting unit requests the second base station to interrupt transmission of a communication packet being transmitted to the access terminal if the calculated result from the calculating unit is equal to or less than the value of the parameter as a result of movement of the access terminal.  
   
   
       5 . A radio communication system including access terminals and a plurality of base stations communicable with the access terminals, comprising: 
 a calculating unit for calculating distance between a first base station selected from the base stations and a second base station selected from the base stations, according to respective positional information of the first and second base stations;    a comparing unit for comparing a calculated result calculated by the calculating unit with a predetermined parameter (Soft Combine Radius (SCR)); and    a determining unit for determining, according to a result of the comparison from the comparing unit, the base station which sends communication packets to the access terminal.    
   
   
       6 . A radio communication system according to  claim 5 , wherein the determining unit determines the second base station as a base station to send a communication packet to the access station if the calculated result from the calculating unit is equal to or less than a value of the parameter.  
   
   
       7 . A radio communication system including a plurality of access terminals and a plurality of base stations communicable with the access terminals, comprising: 
 a power measuring unit for measuring received power received from each of the base stations;    a collecting unit for comparing a measured result measured by the power measuring unit with a predetermined power threshold value and collecting information on the base stations being associated with received power exceeding the power threshold value; and    a determining unit for determining, according to a collection result collected by the collecting unit, the base stations to communicate with the access terminals.    
   
   
       8 . A radio communication system according to  claim 7 , wherein the determining unit selects, from the base stations associated with received power exceeding the power threshold value, n base stations for communicating with the access terminals in descending order of amount of information collected by the base stations.  
   
   
       9 . In a radio communication system including a plurality of access terminals and a plurality of base stations communicable with the access terminals, each of the base stations comprises: 
 a receiving unit for receiving, from each of the access terminals, information of the base stations associated with high received power; and    a determining unit for executing statistic processing for the information of the base stations received by the receiving unit, thereby producing statistic information and determining, according to the statistic information, the base stations to communicate with the access terminals.    
   
   
       10 . A base station according to  claim 9 , wherein the determining unit selects, from the base stations received from the access terminals, n base stations to communicate with the access terminals in descending order of amount of information received by the receiving unit.