An Energy Efficient Distributed Link Scheduling Protocol for Wireless Sensor Networks

To decrease the scheduling length and energy cost, a distributed link scheduling (DLS) protocol is proposed for Wireless Sensor Networks, which is based on graph coloring. Every node is required to construct its two-hop conflict graph, the scheduling order of every link is decided by its priority and interference degree in the conflict graph. The proposed DLS algorithm relaxes the problem of long scheduling length caused by randomize scheduling and frequent state transition in traditional algorithms. Since DLS can assign adjacent slot for every node, the times of node's state transition and the energy cost can be decreased. The efficiency on decreasing the scheduling length and network energy cost of DLS has been analyzed. The simulation results show that the scheduling length of the proposed DLS protocol is less than DS-fPrIM(Distributed Scheduling-fixed Power protocol Interferences Model) and DRAND (Distributed Randomized time slot scheduling) about 12 slots. The scheduling energy cost of DLS is the same as DS-fPrIM, less than DRAND. DLS has less state transitions than DS-fPrIM and DRAND about 1 time. The results also indicate that the proposed DLS protocol has good performance on energy efficiency.