GPS-based geographic addressing, routing, and resource discovery

Reviewer: John S. Edwards

As a recent purchaser of a Magellan Pathfinder GPS system for a cartographically challenged wife, and having read much about the coming advances in GPS applications, I was eager to read this article. The authors introduce their concept by stating, “GPS cards will soon be included in cars manufactured in the US and Europe and possibly in every other form of mobile computer as well.” From this premise, and given that each such device can keep track of its position, they embark on a description of how messages could be addressed to small geographical areas and what types of services might use the techniques. As computer scientists, they succeed in the first case and fall somewhat short in the second. They discuss the relevant emerging protocols and router technology to allow a sender to define a geographic area and target messages to the selected area. They also suggest ways for the targets to decline to receive messages. So far, so good. When they turn to possible services, they mention emergency messages and geographic-multicast advertising messages. The case for emergency services is more believable. With sufficient encryption, the technique could also be used by fire, law enforcement, or military personnel to organize their tasks. GPS is certainly coming.