LAUSR

When there are multiple barriers in a wireless sensor network (WSN), the sleep–wakeup schedule can be used to alternate working barriers to extend the overall network lifetime. However, when one working barrier is being replaced by another, if any intruder comes into the potential-breach-point between these two barriers, the barrier-breach problem may occur. In this letter, the proposed algorithm uses mobile elements to check presence of intruders at potential-breach-points. Compared with the extant algorithms, the proposed algorithm has two major advantages. First, it does not remove crossing barriers, so the overall network lifetime of barrier coverage can be extended. Second, it does not alternate working barriers always based on the order of barrier’s distance to the front side, from near to far, so the sleep–wakeup schedule can be flexibly arranged.