A wireless interface type for OSPF

We report on a new wireless interface type for the OSPF routing protocol that greatly improves performance in multihop wireless networks. In this paper, we describe how to adapt OSPF to adequately handle wireless networks in a scalable manner. Our simulation-based study first illustrates that the operation of legacy OSPF routers in mobile ad hoc network environments can generate prohibitive amounts of overhead for networks as small as 20 nodes. Next, we study the possibility of constraining the number of OSPF adjacencies formed in the wireless network, and find that, while scalability can be improved in this manner, the performance does not approach that of the OLSR protocol designed specifically for mobile networks. Consequently, we describe how OSPF can be extended to incorporate key design concepts from OLSR, such that the scaling performance of OLSR can be approached while maintaining backward compatibility with legacy OSPF routers. Our "wireless" interface type achieves bandwidth efficiency within a factor of two to three of OLSR, and allows wireless networks to be incorporated into larger heterogeneous networks. Finally, we describe some strategies and open issues regarding the composition of large heterogeneous networks including wireless subnets.