能量最佳分簇水下声传感器网络时钟同步研究

Study on Clock Synchronization of Underwater Acoustic Sensor Networks Based on Optimal Energy Clustering

时钟同步技术不仅是水下传感器网络节点协同工作的基础问题也是必要条件。与陆地传感器网络不同,电磁波在水下传播受到的衰减严重,而水声信道带宽窄且信号传播速率低,在水下传播具有很大的时延,给水下传感器网络的时钟同步带来了诸多挑战。文中研究了水下传感器网络的分簇技术,在此基础上提出传感器网络的时间同步算法。该算法将时间同步分为簇间节点同步和簇内同步两个过程,通过求数学期望的方法计算求得最佳的簇数值,当网络分簇的个数为最佳簇数时,全网络的能耗达到最低并延长了网络的生命周期。MATLAB仿真结果表明,与MU-Sync时间同步算法相比,基于能量最佳分簇的水下声传感器网络时间同步算法能耗低且精度高,显示出最佳分簇时钟同步算法的优点。

Clock synchronization technology is the fundamental problem and also a necessary condition for underwater sensor networks＇ nodes to coUaboratively work. Unlike terrestrial sensor networks,acoustic channel bandwidth is very narrow ,resulting in low signal trans- mission rate, and the propagation delay is very large in water. The clustering technology for underwater sensor networks is proposed and synchronization protocol is put forward for underwater acoustic sensor networks on the basis. It divides the time synchronization into inter -cluster and intra-cluster synchronization. The optimal number of clusters are calculated by the method of mathematical expectation. The WSN energy consumption will be the lowest when clustered by the optimal number of clusters, and it improves the lifetime of WSN. The simulation on MATLAB shows that compared with another clock synchronization protocol,MU-Sync, the optimal cluster clock synchro- nization technology not only degrades energy consumption, but also behaves high precision, validating its advantages.