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.