Local area network reactivation in never die network for a large scale disaster

If a large scale disaster such as East Japan Great Earthquake is occurred, many resident areas would be isolated with others because of the disconnection of transportations, communications, and so on. In fact, in the earthquake, there were many areas in the coast side of northern Japan where is isolated because of the damages, blackouts, and congestions of network information systems. In case of such a large-scale disaster, it is considered that there are two important functions for Disaster Information Network System. One is to keep connectivity even if the network condition is bad. Thus, significant information such as rescue and evacuation could be transmitted between disaster areas and disaster headquarter. Another is to reactivate network connections quickly inside of a disaster area. Just after earthquake in a disaster area, local disaster information such as evacuation shelter, food supply, and local damage is tend be important. Therefore, in order to provide local disaster information, network connection within a resident area should be reactivated as fast as possible even if it is isolated from other areas. In this paper, Never Die Network consisted of cognitive wireless networks and satellite system that we have proposed is introduced, and the evaluations are held in assumptions of rural areas such as the coast cities of Iwate Prefecture where heavily disaster by East Japan Great Earthquake. The results shows that the proposed system is quickly recovered than other traditional network systems such as wired, wireless, and cognitive wireless network systems, and it is considered to be useful for the isolation by a ultra large scale disaster.