No abstract

Mobile devices have shown to be very useful during and post disaster. If the communication infrastructure breaks down, however, they become almost useless as most services rely on Internet connectivity. Building post-disaster networks based purely on smartphones remains a challenging task, and, as of today, no practical solutions exist. The rapidly growing Internet of Things (IOT) offers the possibility to improve this situation. With an increase in smart spaces such as smart homes and smart offices, we move towards digital cities that are deeply penetrated by IOT technology. Many IOT devices are battery powered and can aid in mediating an emergency network. In scenarios where the electrical grid is still operational, yet communication infrastructure failed, non-battery powered IOT devices can similarly help to relief congestion or build a backup network in case of cyber attacks. With the recent release of the Bluetooth Mesh standard, a common interface between mobile devices and the IOT has become available. The key idea behind this standard is to allow existing and new devices to build large-scale multi-hop sensor networks. By enabling hundreds of devices to communicate with each other, Bluetooth Mesh (BT MESH) becomes a practical technical solution for enabling communication post disaster. In this paper, we propose a novel emergency network concept that utilizes the parts of digital cities that remains operational in case of disaster, thus mediating largescale post-disaster device-to-device communication. Since the Bluetooth Mesh standard is backwards compatible to Bluetooth 4.0, most of today's mobile devices can join such a network. No special hardware or software modifications are necessary, especially no jail-breaking of the smartphones.