A personal communications system enables the operator to simultaneously transmit voice and data communication to a remote site. The personal communications system is equipped with two telephone line interfaces to allow connection between two remote sites. The connection between the first...http://www.google.se/patents/US5764628?utm_source=gb-gplus-sharePatent US5764628 - Dual port interface for communication between a voice-over-data system and a conventional voice system
Dual port interface for communication between a voice-over-data system and a ...
