Evaluation of Sleep Scheduling Method for Data Collection from Sensor Networks Divided into Local Areas

Various sleep scheduling methods have been proposed to achieve energy efficiency in wireless sensor networks. Although these methods can make most nodes sleep to save energy, they do not give adequate consideration to the amount of data originating in specific areas of the network. The authors proposed a sleep scheduling method that divided a sensor network into an adjustable number of areas to ensure that more than one node remained active in each area, but which required all nodes to be able to access the sink node. However, the conditions of simulation experiments displayed a problem in that all the active sensor nodes sent packets to the sink node at the same time. This paper reports how the problem was solved in fresh evaluations of the proposed method and shows that the proposed method also extends the network lifetime.