无线传感器SMAC协议竞争退避机制分析及优化

针对无线传感器网络能量受限和退避时采用固定竞争窗口的特点，提出了一种基于节点剩余能量和信道冲突次数的MAC协议（EC—SMAC）．该协议改进了SMAC的竞争退避机制，根据节点剩余能量和信道冲突次数来动态的调整竞争窗口，减少传输节点之间的冲突，从而使全网负载均衡，同时延长网络生命周期．仿真实验表明：在保证网络吞吐量和时延稳定的前提下，平均延长了7％的网络生命周期．

Analysis and Optimization of Competition Backoff Mechanism of SMAC Protocol for WSN

We propose a MAC protocol based on node residual energy and the number of channel conflict(EC-SMAC) according to WSN's characteristic that energy is constrained and competition window is fixed when backoff. The proposed protocol improves competition backoff mechanism of SMAC, it dynamically adjusts competition window according to node residual energy and the number of channel conflict, thus reducing conflict between transmission nodes and balancing network load and extending lifetime of network. Simulation results show that our proposed protocol extends 7% lifetime of network under the premise of ensuring network throughput and stable delay.