In this paper, we propose a geographic location-based distributed routing (GDR) system. The GDR system provides information lookup based on latitude and longitude coordinates. Each node of the GDR system utilizes the coordinates as an identifier (ID), and manages an overlay routing table. An ID is generated to reflect the geographical location without using Space Filling Curve (SFC). The ID is in cartesian format (x, y), which represents the longitude x and latitude y. In a system with N nodes, each node has a routing table of size log N and a search is possible in O(log N). We evaluate the routing performance of GDR and other systems based on Chord, Kademlia and CAN. We show that in both the ID is in cartesian format and the ID is generated by using SFC, GDR, Chord and Kademlia have the same mean and the same variance of the path length, while the mean and the variance of the relay length of GDR are smaller than those of Chord and Kademlia. Furthermore, while GDR and CAN have the same mean and the same variance of the relay length, the mean and the variance of the path length of GDR are smaller than those of CAN.

As Internet access had spread, it has become an important potential means of lifeline communication. The Internet can fulfill a role in the everyday life of citizens by offering lifeline communication services such as the police, ambulance, gas, electricity, and water services when an emergency occurs. In these lifeline communications, a caller needs to be able to communicate with the nearby lifeline service in the same manner as on a PSTN (Public Switched Telephone Networks) without being consciously aware of the path the caller's message is taking. Moreover, the lifeline service agency must be able to acquire the caller's location and identity. However, it is very difficult to transfer these essential functions from the PSTN to the Internet without making significant changes, because of large differences between the PSTN and the Internet. In this paper, we discuss how to obtain these functions for lifeline communications in the Internet. We further propose a model and implement a lifeline communication system on the Internet.