An IoTbased Emergency Evacuation System During a fire emergency, most people tend to panic and head towards a known exit that is not necessarily the best option. Therefore, a system that dynamically directs people to the safest exit is needed to reduce congestion, speed up the evacuation process and to save lives. This paper presents a system that uses IoT technologies to track location of the fire and building occupants, and then directs the occupants smartly towards a safe exit. The system uses Bluetooth Low Energy (BLE) beacons for indoor localization using the occupantu0027s mobile phones. The system also tracks areas of danger using smoke and temperature sensors. For resiliency in face of a fire, the system uses multiple networks including WiFi and the DigiMesh. A publishsubscribe architecture using an MQTT broker was implemented. In case of a fire, occupants can use a smart mobile application that provides the occupants with a live map of the current danger levels within the building. In addition, smart exit signs are deployed throughout the building that dynamically change their state based on location of the fire to guide the occupants to safety. Realtime information gathered from sensors and occupants is also provided to emergency response services. The proposed system can be scaled to a citywide emergency network.

An Efficient Staged Evacuation Planning Algorithm Applied to MultiExit Buildings When the occupant density of buildings is large enough, evacuees are prone to congestion during emergency evacuation, which leads to the extension of the overall escape time. Especially for multiexit buildings, itxe2x80x99s a challenging problem to afford an effective evacuation plan. In this paper, a novel evacuation planning algorithm applied to multiexit buildings is proposed, which is based on an indoor route network model. Firstly, evacuees are grouped by their location proximity, then all groups are approximately equally classified into several evacuation zones, each of which has only one safe exit. After that, all evacuation groups in the same zone are sorted by their shortest path length, then the time window of each evacuation group occupying the safe exit is calculated in turn. In the case of congestion at the safe exit, the departure time of each evacuation group is delayed in its arrival order. The objectives of the proposed algorithm include minimizing the total evacuation time of all evacuees, the travel time of each evacuee, avoiding traffic congestion, balancing traffic loads among different exits, and achieving high computational efficiency. Case studies are conducted to examine the performance of our algorithm. The influences of group number, group size, evacuation speed on the total evacuation time are discussed on a singleexit network, and that of partitioning methods and evacuation density on the performance and applicability in different congestion levels are also discussed on a multiexit network. Results demonstrate that our algorithm has a higher efficiency and performs better for evacuations with a large occupant density.