Abstract: The distance to a communicating party is detected using whether or not an electromagnetic-coupled RF field formation is achieved or not as simple measurement means. If the distance to the communicating party is short, i.e., if it is possible to form an RF field, then transmission power is reduced. As a result, power consumption is reduced. Since a reduction in transmission power is accompanied by restriction of the zone in which communication is possible, leakage of information is prevented and security is enhanced.

Abstract: The distance to a communicating party is detected using whether or not an electromagnetic-coupled RF field formation is achieved or not as simple measurement means. If the distance to the communicating party is short, i.e., if it is possible to form an RF field, then transmission power is reduced. As a result, power consumption is reduced. Since a reduction in transmission power is accompanied by restriction of the zone in which communication is possible, leakage of information is prevented and security is enhanced.

Abstract: A communication terminal adaptor, or an automatic dialer, for connecting a communication terminal such as a facsimile apparatus and a telephone line network, is capable of handling both the push button signal and the dial pulse signal in mixed manner, and transmitting the identification information of the communication terminal, stored in advance in the adaptor, upon receiving the tone prompt signal from the destination station without referring to the communication terminal. Thus the telephone connection can be made in simpler and more prompt manner.

Abstract: A data communication apparatus includes a command receiving unit for receiving a command for setting up a call; a discriminating unit for discriminating a bearer capability included in the command received by the command receiving unit; and a judging unit for judging if a modem is to be used or not, in accordance with a discrimination result by the discriminating unit.