A radio telephone system which comprises a base unit (1) connected to a wire line (3) and at least one radio telephone set (2) to be coupled with the base unit (1) through a radio circuit, and in which coupling between the base unit and the radio telephone set is controlled on the basis of an identification...http://www.google.com.au/patents/US5097500?utm_source=gb-gplus-sharePatent US5097500 - Radio telephone system which writes an identification code via radio link when units are electrically connected
