The GLI system: A global system managing geographical location information of mobile entities

We propose the Geographical Location Information (GLI) system that maps a mobile entity on the Internet to a geographical position. Users can look up the latest geographical location information of registered mobile entities (forward-lookup) and can also search for mobile entities within a specified area (reverse-lookup). The GLI system consists of home and area servers. The home server maintains latest geographical location information of the mobile entities and processes forward-lookup requests. The area server maintains the latest geographical location information of the mobile entities in the area that it manages and processes reverse-lookup requests. To provide a highly scalable system, home and area servers are managed in a distributed manner based on a hierarchical server structure and delegation of authority to servers that manage lower layers. To reduce the amount of traffic due to distributed management, the delegation information of authority is cached by the servers. In our performance evaluation of the GLI system, the prototype implementation can handle 4,500-8,000 requests/sec for location lookup and location registration. We found that 52 home servers and 33 area servers are enough to handle all cars in Japan under some assumed parameters through the performance evaluation.