Progressive Route Calculation Protocol for Wireless Mesh Networks

Although network-wide flooding in reactive routing protocols like AODV facilitates the discovery of optimal routes, they engender large control overhead. Some efficient flooding methods cut down the overhead by minimizing the set of nodes participating in packet relays. When used for route discovery, however, these approaches may suppress the detection of optimal routes. A region-based routing (REGR) protocol was proposed in to effectively reduce route discovery overhead without sacrificing route optimality. REGR defines a pre-routing region and tries to find a high-quality route by broadcasting a route request message only within the region. Although the region-limited broadcasting reduces overhead, it is actually not efficient, and may experience frequent packet collision especially in dense networks. In this paper, we propose a progressive route calculation (PROQ) protocol to locate the optimal route around a preliminary route obtained from sketchy network scanning. We propose to use progressive Dijkstra´s algorithm to make nodes on the preliminary route jointly derive a minimum cost spanning tree (MCST) between a source-destination pair. The topology information needed to derive the MCST is delivered along the preliminary route by using unicast packets, which makes the new protocol more efficient and reliable than broadcast approaches. We simulate PROC and compare it with various protocols. The simulation results verify the efficiency of our method.