Maximizing End-to-End Reliability of Routing with Redundant Path by Optimal Link Layer Scheduling

A cross layer approach is important for designing multi-hop wireless network routing protocols. In this paper, we maximize the path reliability by proper scheduling of transmissions at link layer over different paths. In our scheme, each node involved in the routing maintains two paths towards the destination. When forwarding a packet, the transmissions at link layer are optimally scheduled by considering the instantaneous channel reliability, the end-to-end reliability at the parent nodes and the remaining number of transmissions at this hop. We convert the decision process of the transmission scheduling into a Markov decision model and derive the optimal policy using backward induction algorithm. Results show that the end-to-end reliability can be improved significantly with the optimal transmission schedule.