A videoconferencing network for digital computer workstations that operate on a local area network (LAN) to exchange data. The network includes a signalling local area network (A-LAN), connected to a first port of a plurality of workstations, for transmitting and receiving data signals between selected...http://www.google.de/patents/US5374952?utm_source=gb-gplus-sharePatent US5374952 - Videoconferencing system
