ROAL: A Randomly Ordered Activation and Layering Protocol for Ensuring K-Coverage in Wireless Sensor Networks
2007 Third International Conference on Wireless and Mobile Communications (ICWMC'07)
In this paper, we propose a Randomly Ordered Activation and Layering (ROAL) protocol. Each node under the ROAL protocol can decide its eligibility regarding a given coverage degree K at randomly generated activation time using only the coverage status informed from its neighbor nodes located within its sensing region. A new concept of layer coverage also provides a simple and effective reconfiguration method for energy balancing. Using the layer concept, we also propose a circulation scheme to
... culation scheme to reconfigure the set of working nodes in an autonomous way, where the reconfiguration can be performed with a small and almost constant energy consumption. We also provide the model of the expected coverage and connectivity for the layer coverage and show a proper range in which only one node can be activated with regard to a node density and the sensing radius of a node. The simulation results show that the ROAL protocol can guarantee K-coverage with more than 95% coverage ratio, which almost closes to the coverage ratio that is achieved using the geographic coordinate. A significantly extended network lifetime is also observed against the original topology of a given network. Meanwhile, the experimental results on the circulation scheme show that the fraction of total reconfiguration energy becomes less than 1% of the energy consumed for the reconfiguration. Also, we obtain a greatly reduced packet latency, which corresponds to only 5% of the delay that occurred in the ROAL protocol.