无线传感器网络中基于协同压缩方法的MAC协议

基于无线信号的广播本质,利用传统MAC协议所忽略的串音(overhearing)数据,提出一种方法以在媒介访问控制层去除数据的空间相关性.根据串音所接收到的数据,事件监测节点间协同地对自身的数据进行压缩后再发送,从而在链路层减少冗余信息的传输.首先针对节点间的协同数据压缩问题进行量化,建立线性规划模型;进而提出一种近似最优的、更低时间复杂度(O(N2))的启发式节点筛选算法.在此基础上,设计一种能量有效的、基于协同压缩方法的MAC协议(CCP-MAC),可分布式地控制节点实现该节点筛选算法,相应节点可从筛选出的被压缩节点子集中接收串音数据,融合冗余数据以后再进行发送.实验结果表明,CCP-MAC利用串音数据协调节点进行数据压缩,可在很大程度上节约能量,延长网络的生命周期.

MAC Protocol for Wireless Sensor Networks via Collaborative Compression

Based on the broadcast nature of wireless signal, this paper proposes an approach that exploits the overhearing data omitted in conventional MAC protocols to eliminate the spatial correlation. Particularly, sensor nodes can prevent the transmission of redundant data in link layer by using the data they overhear to compress their own sensory data collaboratively before the transmission. Firstly, this paper formulates the problem that sensor nodes collaborate their compression to optimize their lifetime, and establish linear programming model for it. This paper also proposes a lower complexity (O(N²)) heuristic node selection algorithm while achieving a nearly optimal performance. Based on that, an efficient Collaborative ComPression-based MAC (CCP-MAC) protocol is designed to implement the above node selection algorithm in a distributed way. As a result, the corresponding node can receive the data it overhears from the selected sensor node subset to compress redundant data before the transmission. Experimental results show that by exploiting the data nodes overhear CCP-MAC can collaborate the nodes to compress sensory data, thereby conserve energy significantly to prolong the network lifetime.