1Dynamic Routing for Flying Ad Hoc Networks

This paper reports experimental results concerning self-organizing networks of small flying robots without any central infrastructure. Flying ad hoc networks (FANETs) composed of small unmanned aerial vehicles (UAVs) are flexible, inexpensive and fast to deploy. This makes them a very attractive technology for many civilian and military applications. The communication between UAVs is a crucial and very challenging aspect. The main challenge is due to the high-mobility of the nodes. The topology of these networks is more dynamic than that of mobile ad hoc networks (MANETs) and of vehicle ad hoc networks (VANETs). As a consequence, the existing routing protocols designed for MANETs partly fail to track network topology changes. In this work, we present experiments carried out using a test-bed composed of two autonomous fixed-wing UAVs and nodes on the ground. Our experiments aim at evaluating the link performance and the communication range as well as the routing performance. In particular, we compare two different routing algorithms for ad hoc networks: optimized link-state routing (OLSR), and predictive-OLSR (P-OLSR). The latter being an OLSR extension that we have designed for FANETs, which takes advantage of the GPS information available on board. To the best of our knowledge, P-OLSR is currently the only FANET-specific routing technique which has an available Linux implementation. Our experimental results show P-OLSR significantly outperforms OLSR in rerouting in the presence of frequent network topology changes