Patent ID: 7619976

Claim:
A data transmission method in which retransmission requests are issued based on the results of error-correction decoding of received data packets to perform data transmission, comprising: acquiring statistic information indicating whether received data packets have been successfully decoded or not; and transmitting to a transmission source requests to change a window size, which is the number of data units handled in a predetermined layer, based on the rate at which correct decoding has been made or the rate at which correct decoding has not been made, which is indicated by said statistical information, wherein, when the rate at which correct decoding has not been made is greater than a stipulated value or when the rate at which correct decoding has been made is equal to or less than the stipulated value, said window size change request is a request to reduce the window size of a radio link control layer protocol, the rate at which correct decoding has been made or the rate at which correct decoding has not been made is described in terms of the number of data units which have been decoded correctly, or the number of data units which have not been decoded correctly, within a nearest predetermined time interval, and the data transmission is via HSDPA high-speed downlink data transmission which includes a mobile phone.