3-D Simulation of MANET with UAV in Mountainous Areas

摘要

In recent years, there has been a worldwide boom in mountain climbing because the activity has become easier due to the higher functionality and lighter weight of mountaineering equipment. Along with this boom, mountain distress accidents have also increased. In the event of a disaster, effective communication with search and rescue victims is important. Mobile communication in the mountains, however, is limited because radio waves from the base station may be blocked due to topographic features, vegetation in the surrounding environment, etc. Therefore, a mobile ad hoc network (MANET) could be a useful means of communication. Recently, unmanned aerial vehicles (UAVs, e.g., drones and balloons) have become smaller and more sophisticated, with the result that UAVs could now be available as relay devices for MANETs. However, the effectiveness of MANETs in combination with UAVs in mountainous areas has not yet been clarified and no construction method has yet been established. Furthermore, in the case of mountain communication simulations, elevation differences of several thousand meters on mountain trails and radio wave propagation losses peculiar to mountains must be considered, as these conditions differ from those of common MANET simulations. Therefore, in this study, we simulated 3-dimensional MANET with UAVs using the Hotaka mountain range as an example case. Our radio wave propagation model includes the 2-ray ground reflection model, the double knife-edge diffraction loss model, and the standard model of vegetation attenuation. We simulated communication between a climber and a basecamp or hut on the mountain by MANET relayed by drones and a balloon in four scenarios, finding that the UAV expands the communicable area substantially in the mountains. We also examined the influence of rainfall and snow on mountain MANET communication.