# Communication Technologies in Emergency Situations
## 4 Emergency Communications Technologies--A Systematic Literature Review
### Methodology
#### 4.1.4 Included  
Finally, the eligible articles were processed to extract the information regarding the technologies being used, the technologic contributions being addressed, and the type of evaluations supporting those contributions. Table 4 presents the 27 articles with the corresponding data extraction. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Database** & **Query** & **Results** \\ \hline \multirow{4}{*}{Scopus} & TITLE-ABS-KEY (“emergency communications” AND disaster) AND (LIMIT-TO (OA, “all”)) AND (LIMIT-TO (PUBYEAR, 2021) OR LIMIT-TO (PUBYEAR, 2020) OR LIMIT-TO (PUBYEAR, 2019)) & \\ \cline{1-1} \cline{2-3}  & TOPIC: (“emergency communications” disaster) Refined by: OPEN ACCESS & 16 \\ \cline{1-1} \cline{2-3}  & Period of time: 2019–2021. Database: WOS. & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Identification queries and results per database. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Ref.** & **Title** & **Comm. Technologies** & **Contribution** & **Evaluation** \\ \hline
[24] & An overview of aerial wireless relay networks for emergency communications during large-scale disasters & AWRN with multicopter UAVs & Delay, flight schemes, Coverage & Simulation \\ \hline
[33] & Application Research of Tethered UAV Platform in Marine Emergency Communication Network & AWRN with tethered UAVs, Optical fibre (drone-sib), Mesh equipment, 4G-LTE, Automatic Identification System receiver & Data transmission stability and reliability & Field test \\ \hline
[34] & Research on Multi-UAV Networks in Dissster Emergency Communication & SDN-based UAV network & Flight scheme, routing protocols (Network lifetime, and node switching time), Energy Consumption & Simulation \\ \hline
[35] & Fuzzy-logic-based data-differentiated service supported routing protocol for emergency communication networks in underground mines & Hybrid wireless mesh networks & Routing protocol (delay, delivery ratio) & Simulation \\ \hline
[36] & An Efficient Energy Harvesting and Optimal Clustering Technique for Sustainable Post-Disaster Emergency Communication Systems & UAV-supported wireless networks (D2D communications), SWIP technology & Energy consumption, network coverage, network reliability & Simulation \\ \hline
[37] & UAV-Enabled SWIPT in IoT Networks for Emergency Communications & UAV-enabled SWIP technology, IoT & Energy efficiency, network coverage & Simulation \\ \hline
[38] & NOMA-based UAV-aided networks for emergency communications & NOMA-based UAV-aided wireless network, IoT & High spectrum efficiency, massive connections & Simulation \\ \hline
[39] & Performance optimization of tethered balloon technology for public safety and emergency communications & Tethered balloon, WiMax & Delay, throughput, traffic in both directions, SNR & Field test \\ \hline
[40] & Metaheuristic-based optimal 3D positioning of UAVs & UAV’s positioning (Coverage, QoS, forming aerial mesh network to provide emergency communication services) & Aerial wireless mesh networks & Energy consumption, equal load distribution among UAVs, fault tolerance (network lifetime) & Simulation \\ \hline
[41] & Energy minimization UAV trajectory design for delay-tolerant emergency communication & UAV transporting data from and to truck-mounted BSs, Delay & Trajectory algorithm for energy efficiency & Simulation \\ \hline
[42] & Development of IEEE 802.11 compliant antenna with WLAN mobile multimedia messaging application for emergency communication purposes & IEEE 802.11 compliant antenna with WLAN mobile multimedia application & Functionality, Reliability, Usability, Portability, Efficiency, Maintainability & Field test \\ \hline \end{tabular}
\end{table} 
Table 4: Data extraction of the references included in the systematic review.