Proactive route maintenance in wireless ad hoc networks

This paper presents a new routing scheme for wireless ad hoc networks that provides fresh routing information along active routes with affordable cost. The proposed routing mechanism, called proactive route maintenance (PRM), is used to replace the naive route mechanism in existing reactive (on-demand) routing protocols to improve reliability and reduce route discovery cost. The assumption behind PRM is the communication locality, i.e., most data packets are transported along a few active routes. Data packets are forwarded via multiple optimal paths to meet certain QoS requirements, such as fault tolerance and load balance. Routing information is disseminated along active routes and advertised only by active nodes that forward data packets. Alternative paths are dynamically discovered and maintained by active nodes and their 1-hop neighbors (called passive nodes). The routing overhead in passive nodes is light. PRM maintains reliable end-to-end connections in dynamic networks with low overhead, and has the desirable properties including high delivery ratio, low latency, fair load distribution, self-healing, and self-optimization.