The present invention is an E911 backup system that bridges and monitors standard analog E911 trunks in an emergency 911 answering system ("E911"), also know as a public safety answering position (PSAP) equipment. The E911 backup system has the ability to take control of these trunks in the event of...http://www.google.fr/patents/US6327342?utm_source=gb-gplus-shareBrevet US6327342 - E911 backup system for emergency 911 call answering systems
E911 backup system for emergency 911 call answering systems
