# Building Fire Evacuation: An IoT-Aided Perspective in the 5G Era
## 5 Opportunities in the 5G Era
### Network Slicing Technology in Emergency Communication  
Network slicing has emerged as one of the essential components in 5G technologies [88]. Compared with previous mobile network communications, the 5G network allows numerous users with varying requirements to operate within one network. Therefore, it is imperative to apply a technique to subdivide one network into various virtual networks and accommodate various priorities and use cases. By employing network function virtualization (NFV) and software-defined networking (SDN) to manage the dynamically changing capacity requirements, the network slicing technology will fit the needs by unlocking and orchestrating the specific resources to create network slices fitting different application scenarios [89].  
In the 5G era, one of the most useful applications for network slicing is mission-critical communications [90]. Mission-critical communication is mainly used for emergency response (ER) operations where the communication needs to be reliable, available, and secure in any circumstance. In the past, mission-critical communication was mainly supported by public safety networks (PSNs), such as Terrestrial Trunked Radio (TETRA), Digital Mobile Radio (DMR), and Project 25 (P25), all of which are private networks only serving the ER services [19]. To some extent, these networks provide dedicated and reliable communication for mission-critical operations, but they are developed by narrowband communication technologies, so only voice services are supported. With the wide distribution of public cellular base stations and the demand of using faster and rich information communication to support public safety services, such as voice and video calling, internet/intranet access, high-quality imaging, and real-time video recording [91], it is inevitable to evolve PSNs from traditional radio-based networks to commercial cellular networks. However, it is dangerous to directly use commercial cellular networks for ER communication because the reliability, availability, and security of commercial networks may not be guaranteed in some circumstances. For example, in large public events, thousands of mobile usersmay connect to the network at once, causing the network to collapse easily. Emergency communication under the same network can be severely disturbed in such a situation. The network slicing technology provides a possible approach for solving this. Through the 5G network slicing, we can bypass the commercial consumer networks, which may already be congested or at full capacity, and create additional network capacity to support the ER information that involves transmitting significant amounts of real-time data in a reliable and uninterrupted manner.  
In the building fire evacuation situation, a sharp increase of network connection by occupants and citizens may emerge at the surrounding area of the building after the fire occurrence. Therefore, it is necessary to create two slices, one of which is dedicated to emergency responders and the others to serve public users. Communicating under the network slice for ER, the IC can enable liaising with responders in the fire building without interference. As a result, the real-time evacuation progress can be reported to IC clearly and on time. Moreover, the broadband network slice will support many bandwidth-hungry applications to facilitate fire-ground situational awareness. These applications include using drones with high-resolution cameras to monitor fire development on building exteriors and setting up video channels to collect real-time fire situations from the firefighters entering the fire-ground. With the help of the 5G network slicing technology, more effective and efficient fire evacuation and ER operations can be conducted.