# Emergency Communication System Based on Wireless LPWAN and SD-WAN Technologies: A Hybrid Approach
## 2 Related Work
For critical infrastructures or emergencies, Cisco SD-WAN can provide uninterrupted communication services, efficient data transmission, and enhanced security. It enables organizations to prioritize critical traffic and dynamically select the optimal path based on real-time network conditions. Cisco SD-WAN can also detect and respond to threats, ensuring the safety and integrity of data transmission. Overall, Cisco SD-WAN can help organizations to provide efficient and reliable communication services during crises. The authors of [3] offer a dependable, adaptable, and scalable IoT-based system that monitors and alerts passengers and crew to the safest route to muster stations during an emergency evacuation. They also examine the factors that determine a ship's safe evacuation, which could be helpful for other kinds of structures, including schools, homes, and hospitals. This proposal offers an IoT dashboard using a private LTE/4G cellular sensor network and a dependable open-source IoT platform. The suggested architecture recognizes not-safe locations and instantly guides passengers in the safest path to the muster station. Except for implementation approaches, some researchers are focusing on existing network improvement. In case the traditional electric emergency communication system cannot fulfil the requirements of emergency communications, [PERSON] et al. [20] have proposed network architecture for rapidly deploying wireless networks based on Long Term Evolution (LTE) technology. Its design enables the communication between portable terminals, UAVs, data terminals, and dependable users in the field of the cluster coverage area. It is a self-organizing LTE private network for quickly constructing wireless networks. This architecture has multiple LTE mini-base stations covering a communication network area. The nearby base stations can communicate with one another. Building a wireless multi-hop self-organizing network for information sharing requires a wireless channel between the base stations. Once a base station receives pieces of information, it forwards them to neighbor base stations. If one base station fails, neighbor base stations forward the information. This LTE ad hoc network is capable of swift deploying a self-organized communication network and effectively avoiding communication breakdowns. A UAV carries the LTE terminal equipment, a camera, and a processing module for data analysis to get around the limitations of current communication networks. The camera collects video data. After the processing and data analysis, the data package is transmitted from the video device to the command and dispatch desk for monitoring analysis, and further commands. [PERSON] [21] proposed a network case for disasters and emergencies composed of small UAVs instead of a single large UAV for Flying Ad Hoc Networks (FANETs) implementation. The UAVs are highly beneficial in 5G and 6G networks due to their low-cost communication capabilities and flexibility. He introduced a new cluster-size-based back-off mechanism for performance optimization. UAVs join a cluster once deployed in a specific area while the clusters are formed by grouping adjacent UAVs. In every cluster, a Cluster Head (CH) is connected to an Emergency Communication Vehicle (ECV).To explore the performance of this mechanism, a Markov-chain analytical study is presented that takes into account the Nakagami-m fading channels. However, high FANET node mobility can result in rapid topology changes and frequent link breakage, with unstable communications that result in packet losses and collisions. To avoid this issue, the networks can divide into smaller clusters or groups for the efficient control of their topology and channel contention reduction. The performance metrics, influencing parameters, and other relationships among them are taken into consideration while analytical simulation results verify this study. A quantitative comparison of the known cluster-based methods shows that the proposed architecture is superior to all.