## 2 Related Works  
In several reports from emergency management agencies, the first 72-h aftermath the occurrence of a disaster is considered the most critical to organize first response actions and save human lives [18]. In such catastrophic situations, an efficient deployment of mobile wireless communication nodes is an extremely challenging real problem to be tackled, since predeployed network infrastructures may be totally or partly destroyed. A dramatic evidence of this was provided by the Japan earthquake in 2011: over 14,000 cellular base stations were damaged, and one million fixed network lines were out of service [19; 20]. The growing use of mobile devices during the last decade has enabled a better and quicker crisis response against disaster events [21]. Unfortunately, most of these mobile nodes in the composed networks rely on capabilities of wireless equipment, e.g., self-configuration and self-organization; they do not assume the presence of other communication infrastructures within the disaster scenario. In this context, it requires interoperability among highly heterogeneous portable equipment in terms of coverage, cost, autonomy, and other similar factors, to form a temporary DAWN, which requires reliability, interoperability, and adaptiveness [20; 22]. Required mobile nodes can range from traditional RF front-ends installed on ground vehicles and portable masts to last-generation devices operating from unmanned aerial fleets of drones, helicopters, and airplanes. However, the diversity in the set of deployable nodes has produced a lot of research that is directly related to disaster/emergency response communications deployment, especially to the next-hop selection [23]. Mobile nodes deployment represents a very active research niche in DAWNs, as pointed out in [24; 25; 26; 27; 28] by [PERSON], [PERSON], [PERSON], et al., and more recently in [29] by [PERSON], [PERSON], et al. Furthermore, in this context, routing protocols have been extensively investigated for rescue operations in post-disaster scenarios, and several adaptive routing protocols have been proposed. For DAWNs, AODV [30] and LEACH [31] are two classical and popular routing protocols that mainly find a route through flooding and reply messages. As discussed above, many considerations, such as mobile nodes deployment, routing protocols, network bandwidth, etc., need to be associated with resource allocations in DAWNs. In this paper, in order to proceed with the literature review regarding solutions for the optimum resource allocation problem in DAWN, we will focus our study on next-hop node selection protocols under the assumption that mobile node power is constrained for disaster situations. Routing in DAWNs is crucial because of the absence of a central routing. Each intermediate node is part of the path between a source and a destination, and thus is like a router. In [32], [PERSON], et al. designed a framework for disaster management which considered both the reliability and energy efficiency. The authors used the hop-count metric for message transmission, and the message have to reach the destination as quickly as possible due to a high emergency level with fewer hops. A location-based routing protocol for DAWN was presented in [33] by [PERSON], et al. The route was searched based on the request zone during the route discovery. [PERSON], et al. in [34] proposed the forwarding methods of opportunistic networks in disaster areas. The authors compared four different opportunistic routing protocols for emergency scenarios such as Epidemic, MaxProp, Probabilistic Routing Protocol using History of Encounters and Transitivity (PRoPHET), and Time To Return (TTR), but these forwarding methods do not consider the energy for long emergency situations with a high density of nodes or many messages. The hybrid protocol Chameleon (CML), which uses two protocols--AODV and Optimized Link State Routing (OLSR)--was presented in [35; 36; 37] by [PERSON], et al.