Energy- aware mobile element scheduling in wireless sensor networks

Abstract

In wireless sensor networks, scheduling of mobile element has been an important issue because the data sensed by the sensor node has to be collected by this mobile element so that no data loss occurs. Each sensor node senses the data and collects it in a buffer. A deadline is assigned to each sensor node which implies that after the deadline the buffer will overflow which leads to data loss. Since the mobile element acts as the base station to collect the data, many scheduling algorithms have been proposed so that the deadlines have been met without any data loss. The proposed problem involves the variation in the speed of the mobile element depending upon the sampling frequency of the sensor nodes. The speed has to be increased for nodes with high sampling rate because the buffer overflow will be more for these nodes and therefore the data collection has to be done in an efficient manner. This increase in collection of data by the mobile element will minimize the deadlines to be missed by other nodes. Since the variation in speed element should not increase the energy consumption of the mobile element, simplex method is applied in order to determine the optimal energy consumption for various set of nodes. Simulation with a set of sensor nodes by varying it’s deadline shows that the variation in speed of the mobile element does not exceed the optimal energy consumption of the mobile element. Simulation results show that the objective of varying the speed of the mobile element has proved that the number of deadlines missed have been minimized and at the same time it does not exceed the optimal energy consumption required for the mobile nodes.