# Smart Disaster Response in Vehicular Tunnels: Technologies for Search and Rescue Applications
## 3 Proposed Disaster Response Systems for Tunnel Accidents
### Artictecture of Smart Disaster Response System  
We assume that there are at least several Internet protocol (IP) cameras, fire detection sensors (e.g., smoke, temperature, gas sensors, etc.) and radars for tracking moving objects in the tunnel. They are connected to a wired or wireless network (i.e., IoT network). The collected data are stored and monitored through the control server in the tunnel management office. At the initial ignition, the approximate fire point and the position of victims can be known through these IoT facilities. When an accident occurs, the tunnel manager first reports to the fire station after the initial response. The initial response includes operation of a tunnel entrance blocking facility, ventilation fan operation, emergency radio broadcast, and dispatch of tow vehicles when necessary. The principles of the general accident response manual specifies arrival on the spot within 5 min after receipt of the first report, but it is actually difficult to achieve this for tunnels outside the city. For some off-urban highways it takes more than 15 min for fire fighting crews to arrive. Therefore,it is very important to actively work with patrol cars or management staff of the tunnel management agency. As part of the initial response of the on-site patrol officer, an UAV or unmanned ground vehicle (UGV) can be deployed for rapid internal navigation and information gathering. The disaster information obtained from the robot can be transmitted to the surrounding fire fighters through device-to-device (D2D) networking or IoT networks. After the fire fighters arrive, the ubiquitous sensor network (USN) server's initially collected information (e.g., video, fire location) and on-site map data are downloaded to the fire fighter's field command headquarters (or computer in the fire truck). In addition, it is possible to access the web server of the tunnel management office through smart devices (e.g., smart phones, laptop computers) equipped with an Internet interface, which are consulted by the fire fighters before the arrival at the site, so that the initial accident information can be easily downloaded in advance. The field fire fighting commander determines the number of fire fighters to be sent in and the number of additional robots sent in by considering the initial information (e.g., fire location, fire type, map, etc.) obtained from the IoT sensors. The commanding computer uses the information to divide the search area in the tunnel into n areas (Area A and Area B in Figure 1) by accident point or search priority and then assigns a search area to each fire brigade to enter. At this time, according to the situation in the field, robots can be sent in first for the safety of the fire fighters, and the range and procedure of the search operation can be adjusted according to the commander's judgment. Also, to perform an effective search and minimize unnecessary search delays, the unrecovered areas are reallocated to robots or fire fighters who have already completed their search missions. The patrol robot transmits the position information of isolated victims and the accurate fire location through the wireless network to the surrounding firefighters or the command vehicle via its own sensors (e.g., IR camera, temperature sensor, gas sensor, position sensor, etc.). At this time, it is assumed that the fire fighters have wireless terminals using the same wireless channel. Meanwhile, it is very important to search for victims who cannot escape from the tunnel without assistance. The IP camera in the tunnel, the camera of a robot sent in, or a fire fighter may detect them, but a victim may inform the fire fighter of his or her own position using a smart phone. This enables direct communication with fire fighters through long-term evolution (LTE) or WiFi-Direct technology [37]. If a victim does not carry a smart phone, there is no way to confirm his or her location in this way. However, tunnel accidents occur mainly in vehicles.