Patent ID: 7672276

Claim:
A base station apparatus for wirelessly communicating with terminals, comprising: a receiver/demodulator for receiving and demodulating a signal that has been transmitted from a terminal; an information extraction unit for extracting, from the demodulated data, information indicative of the receiving state of the terminal and retransmission control information indicative of arrival/non-arrival of data; a transmit buffer for holding transmit data and retransmit data on a per-terminal basis; a transmit-data size setting unit for setting size of data, which is transmitted to said terminal, based upon the receiving state of said terminal; a transmit terminal selector for deciding, based upon the receiving stale of each terminal, to which terminal the data of said size is to be transmitted; a transmitter for modulating and transmitting the data of said size being held in said transmit buffer; a transmission speed calculation unit for calculating transmission speed based upon size of said transmit data and time of transmission and time of reception of said data; and handover control means for exercising control, if a terminal requires handover based upon a required transmission speed, which is decided by service quality of said transmit data, and the calculated transmission speed, in such a manner that said terminal is handed over to another base station apparatus having a different carrier frequency.