A comparison of OLSR and OSPF-MDR for large-scale airborne mobile ad-hoc networks

In this paper, we compare the proactive MANET routing schemes of OLSR and OSPF-MDR via high-fidelity simulation, and consider their suitability for large-scale airborne networks. A successful MANET routing scheme must be bandwidth efficient and robust to frequent topology changes. To assess the two protocols, we simulate them in networks with up to 400 mobile nodes, under a variety of network densities. We evaluate them on the basis of the amount of routing overhead generated, the rate of successful packet delivery, and the time it takes until all of the routing tables converge. We find that OLSR requires up to an order magnitude higher router overhead than OSPF-MDR, while providing only a marginal benefit in packet delivery success rates. The largest difference between the two protocols is the time it takes for their routing tables to converge in the presence of packet loss. OLSR has consistent convergence times for networks of all sizes, while the convergence time of OSPF-MDR increases with network size.