Sensing coverage hole identification and coverage hole healing methods for wireless sensor networks

Wireless sensor networks are often deployed for event detection and environmental monitoring. However, their success in providing quality of service can only be ensured if the network does not have any sensing coverage holes. The existence of sensing coverage holes is unavoidable due to various factors such as environmental disasters, random deployment and hardware failure of the sensor nodes. Therefore, detecting the sensing coverage holes is essential for the successful operation of the network. We present a chord-based hole detection method for identifying the sensing coverage holes; this method is effective in identifying both closed and open holes in the region of interest. Since it is also necessary to heal the sensing coverage holes to improve the quality of service of the sensor network, we also propose a sensing coverage hole healing method, namely, the chord-based hole covering (CBHC) method. The CBHC method provides complete sensing coverage of the network using the minimum number of sensor nodes by minimizing the sensing coverage area overlap. Additionally, our proposed method for sensing coverage hole identification can also identify the boundary of the sensor network. The simulation results demonstrate the satisfactory performances of both the proposed hole identification and hole healing methods in identifying the sensing coverage holes and efficiently covering the sensing coverage holes, respectively.