Research on Never Die Network for Disaster Prevention Based on OpenFlow and Cognitive Wireless Technology

By large tsunami damage due to the Great East Japan Earthquake, many existing network system stopped functioning in various factors. Even under such circumstances, some of the information communication method that including satellite communications, it was able to recover the Network Connectivity, actually quickly and effectively. Although there are some valid information communicating method in disaster, however the information communication method has a strong and weak points, when using each a single unit, it is not possible to follow the disaster area of the situations to be constantly changing. In addition, the emergency information communication system there may not be available in the battery out and do not know how to use in case of emergency. Therefore, it is important to design a systems available without a disaster by providing enough Network Capability. We develop a Never Die Network (NDN) system that is a new network system to achieve both the Network Capability in the normal and Network Connectivity in disaster based on the experience of Great East Japan Earthquake. In this paper, we propose a method for the system to autonomously derive the optimum packet flow by measuring the communication state such as throughput and packet loss in a system such as to considering multiple different access networks. We prepared a test bed that implements a prototype system, and evaluated based on a disaster scenario.