ABNT: Adaptive beaconing and neighbor timeout for geographical routing in UAV networks

In geographical routing, each node takes forwarding decisions as per position information of neighboring nodes stored in neighbor table. Owing to the highly dynamic behavior of UAV Networks, there is frequent change in topological information so it is challenging to maintain accurate and updated information in neighbor table, which is essential for effective routing. Thus, to maintain an exact view of local topology, periodic beaconing is the most widely used approach. However, the transmission of beacons or hello messages at a fixed rate increases beacon overhead and energy consumption, which negatively affects the routing performance. Therefore, in this work, we propose an adaptive beaconing scheme to control the transmission of beacons at regular interval while improving the accuracy of neighbor table. In this, the fuzzy logic system is used, which combines multiple parameters related to node mobility, traffic load and remaining energy of node to calculate the frequency of beaconing. Additionally, to maintain up-to-date entries in the neighbor table, the timeout timer of each neighbor is computed dynamically by exploiting the mobility features of Unmanned Aerial Vehicles (UAVs) in three dimensional (3D) environment. The performance of the proposed technique is assessed in ns-3 by conducting multiple simulations under different settings. The simulation results indicate that the proposed technique outperforms existing beaconing schemes with regard to beacon overhead, delivery ratio, delay and energy consumption.