Patent ID: 8612554

Claim:
A portable file server configured to wirelessly transmit and receive data to and from a terminal, the portable file server comprising: a radio field intensity input unit configured to receive through an antenna an input identifying a distance indicating a radio field intensity value from a user interface displayed by the terminal; the antenna configured to wirelessly transmit and receive the data within a radio field that is in accordance with a radio field intensity determined by a signal current amount controlled by a current controller; and the current controller configured to increase or decrease the signal current amount for the data in accordance with the radio field intensity value, wherein the user interface presents a list of distinct distances corresponding to a plurality of predetermined field intensities, the input identifies the distance from the list of distinct distances, and the radio field intensity value indicated by the distance is one of the plurality of predetermined field intensities, wherein each distance represents an effective distance of the radio field for wirelessly transmitting and receiving data to and from the terminal, wherein the radio field intensity input unit receives the input from the terminal if a password received from the terminal matches a password stored in the portable file server, and wherein the radio filed intensity value is selectable by both the portable file server and through the user interface displayed by the terminal when the password received from the terminal matches the password stored in the portable file server.