Patent ID: 7664502

Claim:
A radio network controller ( 100 ) for controlling a plurality of base stations (BS 1 , BS 2 , BSX) communicating with a mobile terminal (MT) via radio, wherein said radio network controller ( 100 ) selects a frame to be transmitted to a fixed network (N) from among frames having same content which is received from the same mobile terminal (MT) via different base stations (BS 1 , BS 2 , BSX), said radio network controller ( 100 ) comprising: a buffer ( 160 ) which buffers said frames respectively received from said different base stations (BS 1 , BS 2 , BSX) and has a predetermined capacity determined in accordance with a predetermined data transmission time difference; a transmission time difference detecting section ( 144 ) which detects a data transmission time difference as a difference between data transmission times of different paths from the different base stations (BS 1 , BSX) to said radio network controller ( 100 ); a buffer control section ( 152 ) which expands the capacity of said buffer ( 160 ) when said transmission time difference between a new base station (BSX) commencing communication with said same mobile terminal (MT) and another base station (BS 1 ) already communicating with said same mobile terminal (MT) is larger than said predetermined data transmission time difference; and a buffer assigning section ( 153 ) which assigns storage locations in said buffer ( 160 , 161 ) to said received frames, and wherein said storage locations in said buffer ( 160 , 161 ) to be assigned to said frames are each determined in accordance with a remainder that is generated when a frame number is divided by a given divisor, wherein the frame number appended to each of said received frames indicates a transmission order of the received frames.