Network connection of a terminal such as a mobile apparatus can be implemented at a transmission speed higher than that by a radio LAN. A connection method between a terminal and a connection apparatus is configured by replacing a radio LAN with electromechanical coupling, and transmission between the terminal and the connection apparatus is carried out using a baseband as it is without up conversion into a radio frequency band. This eliminates a bottleneck by the throughput of the radio LAN and eliminates the problems of the cost and the power consumption which arise from up conversion of a transmission signal. Further, bridging of data can be carried out by simple code conversion, and since the apparatus configuration is simplified, the cost can be reduced.