The wireless sensor network is a resource-constrained self-organizing system that consists of a large number of tiny sensor nodes. Due to the low-cost and low-power nature of sensor nodes, sensor nodes are failure-prone when sensing and processing data. Most presented fault-tolerant research for wireless sensor networks focused on crash faults or power faults and less on Byzantine faults. Hence, in this paper, we propose a power-saving data aggregation algorithm for Byzantine faults to provide power savings and high success rates even in the environment with high fault rates. The algorithm utilizes the concept of Byzantine masking quorum systems to mask the erroneous values and to finally determine the correct value. Our simulation results demonstrate that when the fault rate of sensor nodes is up to 50%, our algorithm still has 48% success rate to obtain the correct value. Under the same condition, other fault-tolerant algorithms are almost failed.

The AODV routing protocol, which is simple and efficient, is often used in wireless sensor networks to transmit data. The AODV routing protocol constructs a path from the source node, which detects the target, to the sink node. Whenever the target moves, the path will be reconstructed and the RREQ packet will be broadcasted to flood the wireless sensor network. The localization repair routing protocol sets up a reconstruction area and restricts the broadcast of the RREQ packet to that area to avoid broadcast storm. However, this method cannot reconstruct the path once the target moves out of the reconstruction area. In this paper, we propose a lightweight routing protocol for mobile target detection. When the path breaks because of the movement of the target, the nodes can repair the path effectively using the presented routing information to achieve the lightweight effect.