Abstract—Barrier coverage based on Wireless Sensor Net-works (WSNs) has been widely used to prevent intruder tres-passing in monitoring systems. Traditionally, enabling perfect barrier coverage is considered the most important goal of barrier coverage studies. Imperfect coverage has been deemed to be a failure. In our research, we attempted to use the redundant sensor nodes in WSNs to prolong the optimal network lifetime of barrier coverage by adding imperfect barrier coverage. Specifically, we devised two schemes, CIBC-1 and CIBC-2, to construct imperfect barrier coverage in order to improve the performance of the existing optimal network lifetime scheduling algorithms for barrier coverage. Our simulation results indicate that our schemes ...