A new hybrid approach for scalable table-driven routing in MANETs

OLSR is one of the representative proactive routing protocol for MANETs. However, link-state routing scheme in general poses high load with control messages so that reducing the control load is highly required. On the other hand, table-driven distance-vector routing is known as a low-load routing protocol. However, since it requires large time for path convergence in face of topology changes, it is generally not suitable for MANETs. There are several hybrid routing protocols of link-state and distance-vector schemes in the literature to take advantages of both schemes. By applying link-state schemes only for destinations within k-hop distance, they can reduce control load significantly while keeping fast convergence for destinations within k-hop distance. However, they fundamentally have a drawback of slow convergence for destinations outside the k-hop area even if topology change occurs as close as within k-hop distance. In this paper, we propose a new fundamental mechanism of hybrid routing protocol that also apply link-state routing within k-hop area, but achieves fast convergence for all destinations. Our new proposal takes both fast convergence and low-load advantages for every destination, which namely means to achieve a new design of scalable table-driven routing protocols that have both advantages of link-state and distance-vector routing schemes in the fundamental mean.