IEEE 802.22-based WRAN system for disaster-resistant network systems

When the great disaster strikes, it is most important for victims to receive and transmit appropriate information in order to evacuate immediately and to request for assistance and rescue. The Great East Japan Earthquake teaches us the importance of information communication technology (ICT) using wireless communication technology, e.g., television (TV), radio, the community wireless system for disaster, and mobile phone. However, after the disaster occurrence, particularly, mobile phones were left unusable for a long time due to network congestion, physical damage to base stations, and out-of-fuel of standby power systems. To combat these problems, the ICT services require more robustness, availability, flexibility, and redundancy. In this paper, we discuss the competence of IEEE standard 802.22-based wireless regional area network (WRAN) using television white space (TVWS) which can provide wide service area and utilize geographically or temporally unoccupied resource of TV frequency bands, although the frequency bands are allocated by regulatory domain. Furthermore, we introduce and evaluate a developed prototype of the WRAN equipment. The prototype provides point-to-multipoint service and throughput up to 12.2 Mbps in downstream (DS) and 9.5 Mbps in upstream (US).