Opportunistic Routing Protocol For Asynchronous Duty-cycled WSN

Opportunistic Routing(OR)is adapted to improve the performance of low Duty-cycled Wireless Sensor Networks by exploiting its broadcast nature.In contrast to traditional routing,where packets are transmitted along pre-determined paths,OR uses a prioritization metric to select a set of candidates as potential forwarders.This solves the sender's waiting time problem.However,too many candidates may simultaneously wake up,generating more duplicate packets,occupying the restricted resources and hinder the packet delivery performance.Consciously,to restrict the number of candidates and to counterbalance between the waiting time problem and the duplicate packets problem,this research proposed a new protocol that combines two main parts.First,each node defines a Candidates Zone(CZ)such that the packets generated by the node will be routed via any path within the CZ.Expressly,the nodes within the CZ are allowed to be selected as candidates.The size of CZ is controlled by the network density.Second,the candidates within the CZ are prioritized based on the OR metric,which is defined as the multiplication offour-distributions:direction distribution,transmission-distance distribution,perpendicular-distance distribution and residual energy distribution.Through an extensive performance evaluation study and simulation of large-scale scenarios,the results demonstrated that our protocol achieved better performance compared to the state-of-the-art solutions in terms of network lifetime,energy consumption,routing efficiency,sender waiting time and duplicate packets.