An efficient storage policy for moving target path extraction in wireless sensor networks

In wireless sensor networks, the storage policy of the sensed event affects the number of control messages required. If the number of control messages can be reduced, the network lifetime can be increased because transmitting unnecessary control messages requires extra energy consumption. A local storage method with a small control overhead is proposed for an object-tracking application in wireless sensor networks. The main idea is to store the detected events in a local storage and maintain the relation of the sensed data through a low-cost implicit linked list among sensor nodes. When an object moves across the sensing field, the detecting sensor can automatically construct a linked list along the moving path of the object. The stored event records can be extracted by tracing the linked list from head to tail to obtain the complete information. When the memory space in a sensor node is full, a link reconstruction mechanism is proposed to distribute the heavy loads of sensor nodes to nearby nodes. Finally, performance analysis and simulation have been conducted to verify that the proposed method can reduce the amount of control messages and increase the network lifetime.