Patent ID: 6845090

Claim:
A communication system, comprising: a first terminal device connected to first and second networks, having only a reception function with respect to the first network and transmission and reception functions with respect to the second network, the first network being a radio network according to IEEE 802.11 and the second network being a radio network slower than the first network; a second terminal device connected to the first network and a third network different from the first and second networks, having at least a transmission function with respect to the first network and transmission and reception functions with respect to the third network; a third terminal device connected to the second and third networks, having transmission and reception functions with respect to the second and third networks; and a fourth device provided on the third network, having transmission and reception functions with respect to the third network; wherein the first terminal device carries out a prescribed procedure required in using the first terminal as a receiving side in the first network, by carrying out communications with the third terminal device through the second network; the third terminal device carries out the prescribed procedure by carrying out communications with the second terminal device through the third network; the third terminal device carries out another prescribed procedure required in relaying packets transferred from the fourth device towards the first terminal device at the second terminal device, by transferring a control information received from the first terminal device through the second network, to the second terminal device through the third network; the first terminal device transmits a packet transmission request with respect to the fourth device, to the third terminal device through the second network; the third terminal device transfers the packet transmission request received from the first terminal device, to the fourth device through the third network; the fourth device transmits packets in response to the packet transmission request received from the third terminal device, to the second terminal device through the third network; and the second terminal device transfers the packets received from the fourth device, to the first terminal device through the first network.