# Communication Technologies in Emergency Situations
## 4 Emergency Communications Technologies--A Systematic Literature Review
### Communication Technologies Integration  
As can be seen up to now, a lot of works included in this systematic review focus on the deployment of Aerial Wireless Networks from several different perspectives. However, none of the papers presented until now include any integrated solution. Not surprisingly, in this short range category, there are also some works including Internet of Things (IoT) technologies. Indeed, the following highlighted works integrate Aerial Wireless Network technologies with IoT. Ref. [58], for example, studies the network performance of collaboration between the Internet of Public Safety Things (IoPST) and drones, as this collaboration can support public safety requirements such as real-time analytics, real-time monitoring, and enhanced decision-making to help smart cities meet their public safety requirements. The contribution of this work lies in improving the level of public safety in smart cities through collaborating between smart wearable devices and drone technology. Thus, the collaboration between drones and IoPST devices establishes a public safety network that shows satisfying results in terms of enhancing efficiency and information accuracy. More in line with the previous references, in [38], an emergency communications framework of NOMA-based UAV-aided networks is established. The addressed disaster scenarios are divided into three broad categories, referred to as emergency areas, wide areas, and dense areas. First, a UAV-enabled uplink NOMA system is presented to gather information from IoT devices in emergency areas (with a DQL-based path planning algorithm to identify the priority devices). Then, a joint UAV deployment and resource allocation scheme for a multi-UAV enabled NOMA system is developed to extend the UAV coverage for IoT devices in wide areas. Furthermore, a UAV equipped with an antenna array has been considered to provide wireless service for multiple devices that are densely distributed in disaster areas. Simulation results are provided to validate the effectiveness of the above three schemes. A couple of even more relevant works, from our point of view, also integrate SWIPT technology in the integration of Aerial Wireless Networks and IoT. Ref. [37] establishes an emergency communications framework of UAV-enabled SWIPT for IoT networks. First, the trajectory optimization and beam pattern design have been investigated to deliver energy for IoT devices in densely distributed areas. Then, a trajectory planning and resource scheduling scheme has been established to provide wide-area wireless services for users. Furthermore, a dynamic path planning scheme with an intelligent prediction mechanism is established to improve the EE of the system. In line with this last point, in [36], an efficient UAV-assisted emergency communication with clustering techniques was adopted in which an optimal cluster head was introduced and utilized to harvest energy for stable networks that enhanced the network coverage and reliability. Finally, in [33], a wireless emergency communication relay system based on a single tethered UAV is presented. From the perspective of practical application in a maritime emergency, the characteristics and network coverage of the emergency communication system are analysed. The tethered UAV is equipped with various communication loads such as a MESH self-networking relay station, 4G-LTE (long term evolution fourth generation mobile communication) base station including NB-IOT narrowband Internet of Things function, AIS (Automatic Identification System), and so on. When the communication support ship enters the scene of maritime emergencies, the tethered UAV platform lifts off, stays for a long time, and realizes the relay communication service of various carriers within a radius of tens of kilometres through its various communication payloads, which provides key communication support for the Marine emergency communication network. Indeed, ref.