PURPOSE: To attain the transmission of both data with satisfied quality by using a protocol respectively suitable for control data and multimedia data.

CONSTITUTION: Control data received by a terminal control data communication section 35 are fed to a terminal control section 32 and multimedia data received by a multimedia data reception section 36 are fed to a decoding section 33. The control section 32 controls the decoding section 33 according to the control data similarly to the case with a conventional system and the decoding section 33 applies expansion decoding to the multimedia data and outputs the data through a multimedia data output section. Thus, a protocol suitable for the control data in which reliability with respect to a data error has precedence is used for the control data and a protocol suitable for transmission of the multimedia data in which time-consecutiveness suitable for the transmission has precedence is used for the multimedia data and then both the data are sent. Thus, both the data are sent with a quality satisfying the both.