Investigations on error control schemes in heterogeneous sensor networks

Abstract

Sensor networks offers numerous applications in the field of military surveillance, broadcasting, environmental monitoring, structural monitoring, disaster prevention, oil exploration, data collection, physiological parameter monitoring, industrial and other scientific purposes. Sensor network is a network of several minute, self-directed and low powered devices called sensor nodes or motes. Sensor nodes are miniature devices with limited power resource. These nodes are capable of sensing various parameters from the environment wherein they are deployed. The gathered information from the monitored field is transmitted wirelessly to the sink or Base Station (BS) by multiple hops. The sensed data is transmitted over dynamic wireless channel with low transmission power by small size antennas. This leads to decreased Signal to Noise Ratio (SNR) which in turn decreases the data transmission reliability.To achieve reliability and to ensure the quality data transmission in sensor networks, error control methods are applied. These error control techniques aid the receiver in restoring the lost and erroneous data packets. The three effective error control schemes are Forward Error Correction (FEC), Automatic Repeat Request (ARQ) and Hybrid Automatic Repeat Request (HARQ). Based on the nature of sensor network and kind of parameter sensed, the error control method adapted will be different to overcome the errors and loss. In this research work, three different kinds of sensor networks are considered for the study by proposing appropriate error control schemes to enhance reliability which in turn improves the network life time. Identified error control methods improve the energy efficiency and reduce retransmissions. Energy analysis is carried out in common for all the three scenarios. newline