Optimizing Routing Performance in Flying Ad-hoc Networks using an Adaptive Hello Interval Scheme

Abstract

Hello messaging is a widely used scheme to obtain local link connectivity infor- mation. Traditional routing protocols that are used for FANETs scenarios, includ- ing the well-known Ad hoc On-Demand Distance Vector Routing (AODV) and Optimized Link State Routing (OLSR), make use of fixed hello interval for peri- odic hello messages to realize the change in the topology to maintain the local connections up-to-date. However, it involves a tradeoff where a shorter value of hello interval ensures quick detection of link changes but also leads to an increase in the overhead and energy consumption. On the other hand, a longer hello in- terval reduces overhead and energy consumption but compromises the ability to discover new neighbors and detect link breaks promptly. One of the approaches to balance this tradeoff is to make the hello interval scheme adaptive such that the value of the hello interval is not fixed but is adjusted according to the network conditions.This work proposes an adaptive hello interval scheme which sets the hello in- terval based on three network parameters, namely the transmission range of the UAV, the network density of the node, and the relative speed of UAV with re- spect to neighboring UAVs. Considering relative speed ensures that the UAV evaluates the movement dynamics of nearby UAVs when setting the hello inter- val. This refinement contributes to improved performance in terms of throughput and overhead efficiency while simultaneously reducing the network's overhead and energy requirements.