In Wireless Sensor Networks (WSNs), a big hole is formed due to the non-uniform deployment, node failure and movement of animals’ residence or fierce wind blowing, resulting a region without sensor working for sensing and communication tasks. The existence of big hole will reduce both the accuracy of the environmental monitoring and the efficiency of sensing and communications. Recently, many studies proposed mechanisms to detach a robot that loads up static sensors to heal the hole and maintain the spatial full coverage. Some other studies utilized mobile sensors to patrol the hole, maintaining the temporal full coverage. However, an irregular hole will result in the redeployment and patrol inefficiency. This thesis proposes a novel mechanism to regularize a big irregular hole for a mobile WSN. Mobile sensors who detect the big hole cooperate with each other to change the shape of the irregular hole to a convex and regular one in a distributed manner. The robot’s redeployment and the mobile sensors’ patrol are therefore can be more efficient. Simulation results reveal that applying the proposed HONOR mechanism saves power consumption and delay time for the robot’s redeployment and the mobile sensors’ patrol.