We propose several localized sensor area coverage protocols for heterogeneous sensors, each with arbitrary sensing and transmission radii. Each sensor have a time out period and listens to messages sent by respective nodes before the time out expires. Sensor nodes whose sensing area is not fully covered (or fully covered but with a disconnected set of active sensors) when the deadline expires decide to remain active for the considered round and transmit an activity message announcing it. In our approach, sensor decides to sleep only if neighbor sensor is active or not covered. Covered nodes decide to sleep, with or without transmitting a withdrawal message to inform neighbors about the status. After hearing from more neighbors, inactive sensors may observe that they became covered and may decide to alter their original decision and transmit a retreat message. Localized Sensor Area Coverage With Low Communication Overhead
In existing method, sensors are not in a proper contact with its neighbor pair. If the time-out period is over for a sensor, it will go to sleep with out any warnings. This leads to collision and data loss. Here, resources are not using in proper. For dense networks, fails to cover the area reasonably with a connected set of active nodes. Nodes may not know which sensor currently communicates with it.
In proposed system, have proper communication with sensors. All the sensors will keep the list of devices which communicates at a time. Here, each sensor communicates with all the sensors on the network and/ or with neighbor sensors. Sensors with low time-period watch all the neighbors and if they are available, sensor turns to sleep, and all the devices will assigned to particular neighbor sensor. This method is robust in terms of high area coverage with a reasonable amount of active sensors and connectivity preservation despite message losses.