A new version of the greedy perimeter stateless routing scheme in flying ad hoc networks

Flying ad hoc networks (FANETs) belong to the family of mobile ad hoc networks (MANETs). They have gained high popularity due to their extensive applications in various industries such as emergency management, military missions, and supervision. However, these networks face important challenges in guaranteeing reliable data transmission because of their dynamic nature and lack of infrastructure. In this paper, a new version of the greedy perimeter stateless routing scheme called GPSR+AODV is proposed in FANET. It combines two routing schemes, namely GPSR and AODV, and is a family member of geographic routing methods. In GPSR+AODV, each UAV consists of a certain hello broadcast period that is adjusted based on the prediction of its spatial coordinates in the future. Additionally, GPSR+AODV modifies the greedy forwarding process and restricts the search space for finding the next-hop node by obtaining a refined candidate set, calculated in the cylindrical coordinate system. Then, each UAV in the refined candidate set is evaluated under a fitness function, and the most suitable next-hop node with the maximum fitness is determined. This function is a combination of four criteria, namely relative velocity, energy level, buffer capacity, and distance to destination. When failing in the greedy forwarding process, GPSR+AODV changes the forwarding technique and uses an AODV-based perimeter forwarding technique to select the best next-hop node. Lastly, GPSR+AODV is implemented by the NS2 simulator, and the simulation results show a successful performance in terms of packet delivery rate, throughput, and delay compared to AGGR, AeroRP, and GPSR. However, the routing overhead in the proposed scheme is higher than that in AGGR.