Patent ID: 7701855

Claim:
A communication device adapted to select one of a plurality of stepwise differentiated transmission speeds as the transmission speed to be used for data communication between itself and another communication device through at least one intervening a processor communication device, the device comprising: a maximum speed information requesting section adapted to transmit a maximum speed information requesting command only to said another communication device at the minimum one of the transmission speeds, requesting transmission in return of maximum speed information for target node, which is the maximum data communication speed information of said another communication device; a maximum speed information acquisition section adapted to acquire maximum speed information for target node from said another communication device; a confirmation information transmitting section adapted to transmit confirmation information for confirming the capability of transmission for data communication with said another communication device, switching the transmission speed for transmitting the confirmation information within a range between an upper limit equal to speed of the maximum speed information of the self node, which is the maximum speed for the communication device to transmit data to another communication device, or that of the target node, whichever lower, and a lower limit equal to the transmission speed higher than the minimum transmission speed by a step; and a transmission speed selecting section adapted to detect the reception information transmitted back from said another communication device in response to the reception of the confirmation information, and select the maximum transmission speed for the detected reception information as transmission speed for transmitting data to said another communication device for data communication.