A cordless telephone is composed of a base unit connected to a telephone line and a handset unit capable of radio communications with the base unit. When the handset unit or the base unit initially transmits radio waves for forming a radio link, a channel is selected from a group of channels through...http://www.google.fr/patents/US5870678?utm_source=gb-gplus-shareBrevet US5870678 - Cordless telephone apparatus
