A portable server has an antenna and radio communicating portion having a receivable distance of several m to several tens of m and an authentication antenna and authentication radio communicating portion having a receivable distance of several mm to several cm, which is extremely shorter than the receivable distance of the radio communicating portion. When an authentication button is operated by a user and when another apparatus is arranged within a range of the receivable distance of the authentication radio communicating portion, the authentication radio communicating portion performs authentication processing with the other apparatus through the authentication antenna and registers authentication data resulting from the authentication with a memory. The radio communicating portion connects to the authenticated other apparatus through an antenna based on the authentication data and performs data communication. The invention is applicable to a radio communication system including a mobile terminal.