Directional Antenna Control Based Mobile Adhoc Network for Disaster Information System

Japan is one of the most frequent occurrence countries of the natural disasters in the world such as earthquake and tsunamis as represented by the great 2011 East Japan earthquake. When large disaster occurs, information and communication technology performs the most important role to protect or reduce the damage from the serious disaster. Especially the residents in the mountain area are completely isolated by cutting off the information network. In the stricken area, inter-vehicle communication means are suitable from the points of mobility and preservation of electric power supply to be able to reconstruct the information network quickly. However, in mountain area, it is difficult to arrange the place for vehicles to guarantee the enough communication quality and distance between the communication nodes. In order to preserve the enough communication distance, directional antenna is used. However, the direction of both antennas between the neighbor communication nodes has to be identical. In this paper, we introduce a directional antenna control method for mobile adhoc network for disaster information system. The antenna direction both nodes are controlled by antenna actuator using the GPS data and electric power density. By exchange the GPS data between the communication nodes, rough antenna can be realized, then more correct control can be realized by periodically observing the power electric density and control the direction more precisely and correctly to maximize their intensities. In order to verify the effect of the control method, a prototype system is build and evaluated the performance of the suggested method.