A system for determining whether or not two of a plurality of nodes (transmission devices) disposed in a complicated communication network, which includes control signal transmission paths and main signal transmission paths in a mixed condition, are physically connected to each other by...http://www.google.fr/patents/US5841761?utm_source=gb-gplus-shareBrevet US5841761 - System for detecting a connection state between two nodes in a digital communication network
System for detecting a connection state between two nodes in a digital ...
