【摘要】 现有的时间同步算法大多采用消息交换来实现较高的同步精度,存在节点通信开销过大、能耗不均等问题。为此,提出一种能量均衡的低开销时间同步算法。该算法基于簇状层次型网络拓扑,簇头间采用双向消息交换机制完成到Sink节点的同步,并利用最大似然估计补偿节点时钟频偏和相偏,提高簇间同步精度,降低同步过程频次。簇成员节点采用双向消息交换机制和参考广播机制相结合的方式与簇头同步,考虑节点广播特性及剩余能量参数,在降低节点开销的同时均衡各节点能耗。仿真结果表明,该算法在保证一定精度的同时,可降低网络通信开销、均衡节点能耗与长整个网络寿命。更多还原

【Abstract】 Aiming at the problem of high overhead and unbalanced energy consumption caused by exchanging majority of messages for higher accuracy in typical algorithms,an energy-balanced and low-overhead time synchronization algorithm for wireless sensor networks is proposed.Based on a hierarchical topology /cluster heads accomplish the process by pair-wise message exchange mechanism with the Sink node,and adopt maximum likelihood estimation for the clock offset and skew correction,thus improving precision and decreasing the times of the synchronization process.Considing broadcasting properties and remaining energy,cluster members synchronizes to their cluster head by adopting pair-wise packet exchange and reference broadcast mechanism,thus reducing numbers of transmission packets and balancing the energy in the network.Simulation results show that the proposed algorithm relatively has less packet cost,balances the energy consumption and extends the network lifetion.while guaranteeing the precision.更多还原