A distributed communication system that is capable of providing emergency call diversion during an event such as a power outage, network or sub-network failure, site closure, or the like, allows devices within the system affected by the event to rapidly inform one another that it is necessary to enter...http://www.google.com/patents/US20030185200?utm_source=gb-gplus-sharePatent US20030185200 - System and method for emergency call diversion
