面向用电信息采集系统的无线传感器网络MAC协议研究

Research on MAC Protocol in Wireless Sensor Networks for Electricity Information Collection System

针对用电信息采集系统簇头采集器缓存占用率过高且易造成网络拥塞的问题,提出一种节点优先级自适应的PA-MAC(priority adaptive MAC)协议,根据缓存占用率动态调整节点优先级,增强缓存占用率高的节点的信道竞争力,增加节点的数据发送量,使得缓存占用率维持在较理想的水平;然后采用分布式算法,利用节点发送数据包的传输情况评估网络负载状态,结合缓存占用率及当前竞争窗口取值范围,调整竞争窗口的变化,降低数据包的碰撞概率。仿真结果表明,本算法有效缓解了采集器节点的缓存压力,提高了用电信息采集系统本地网络在归一化吞吐量、丢包率及有效传输数据量等方面的性能。

As the cluster head collector in the electricity in- formation collection system has high buffer occupancy rate, a priority adaptive MAC （PA- MAC） protocol is presented to regulate node priority adaptively according to the buffer occupancy rate, which enhances the competition of channel for the nodes with high buffer occupancy rate, and increases data transmission quantity of nodes. By using of distributed algorithm, network load state is evaluated by the transfer- ring status of data packets of node. And by combining buffer occupancy rate and value range of current competing win- dow, the variation of competing window is regulated to re- duce collision probability of data packets. Simulation results show that this algorithm relieves buffer pressure of.collector nodes, and improves such performances as normalized satu- ration throughput, packet loss rate, and congestion recoveryof local network for electricity information collection sys- tem.