# Communication Technologies in Emergency Situations
## 3 Desk Research
[16] provides some guidelines on the most suitable communication technologies based on the type of data to be transmitted (including multimedia). In contrast, in this work, this classification is considered too basic for such a complex scenario (network availability, number of users, area to be covered, QoS required, etc.) and thus, it focuses in proposing a model for integrating all these technologies while guaranteeing the ubiquity of the complete solution, while leaving the optimization problem for future works. Another interesting and very recent survey about ICT usage in disaster management can be found in [17]. It describes not only the novel technologies for emergencies but also includes the current ones. Moreover, its scope is very broad because it tries to address all the ICT networks, services, and applications for the complete emergency domain including pre-emergency situations, during emergency scenarios, and post-emergency scenarios. Due to this, the technologies are described at a very high-level and details on Emergency Communication Systems are missing. Nevertheless, it is important to mention that, in this paper, the future technologies are already referred to as _integrated_ emergent ICT networks, services, and applications, because, as is also claimed in the present review, it is impossible to address future ECS without considering the integration of several communication technologies. Ref. [18] presents the concept of Always-On-Networks (AoN) together with a survey on Emergency Communication Systems during a catastrophic disaster. The paper is very interesting and aligned with our review because it focuses on the possible strategies for setting up ECS and the corresponding constraints. Among the requirements, it includes a crucial point which is usually disregarded in most of the works, but especially important from the first responders' perspective, that emergency communication equipment that is not utilized ordinarily tends to fail during an emergency. Nevertheless, the work is very brief and only addresses a few of the possible communication technologies. Ref. [19] describes several case studies of communications systems during harsh environments. It analyses the effects of several real natural disasters on the communication networks and concludes with the definition and description of the requirements for ECS. While it is interesting in its discussion on the requirements of QoS, it totally lacks communication technologies' identification or description. Nevertheless, it is still important to confirm that the requirements presented previously in our paper are aligned with the well-justified ones from [19]. Ref. [20] presents another interesting overview of a post-disaster emergency communication systems in the future networks. Far from being a formal survey or review (as it does not include many references to other works), it includes an interesting classification of the emergency communications based on three network scenarios: congested networks are addressed through priority services, partial networks through device-to-device communications, isolated network scenarios through mobile ad-hoc networks, and drone-assisted communication. Furthermore, a comparative description of the most important wireless technologies for post-disaster emergency management systems is also presented, including, apart from the traditional advantages and disadvantages, their deployment cost and their Quality of Resilience (QoR), parameters not included in the other identified surveys but considered truly relevant from our point of view. Refs. [21; 22; 23] are three interesting surveys focusing on the integration of satellite communication, air networks, and terrestrial networks. Ref. [21] refers to hybrid satellite-aerial-terrestrial networks (HSAT) for emergency scenarios. It includes the architecture of HSAT communication systems and a complete comparison between the characteristics of satellite, terrestrial wireless, and aerial platform systems.