Energy-efficient algorithms for lossless data compression schemes in wireless sensor networks

Abstract

Wireless sensor networks (WSNs) are reliant on limited power resources, primarily provided by small batteries within sensor nodes. Inefficient energy management within these networks can lead to premature battery depletion during data transmission between sensor nodes, significantly impacting network longevity. Data compression emerges as a viable strategy to mitigate energy consumption by reducing data size before transmission and employing various compression and decompression techniques. This work presents a comparative analysis of data compression algorithms tailored for WSNs. It studies and enhances two adaptive lossless data compression techniques, namely ‘Adaptive Lossless Data Compression’ (ALDC) and ‘Fast and Efficient, Lossless Adaptive Compression System’ (FELACS), as means to effectively manage energy consumption in wireless sensor networks. ALDC and FELACS algorithms encode differences between consecutive data readings, thereby reducing the number of bits required for encoding. ALDC employs Huffman coding, while FELACS leverages the Golomb-Rice coding method. Encoding data samples by using three Huffman tables interchangeably as an enhancement of the ALDC algorithm, resulted in an improvement in energy saving from 73 % to 77 %. Analysis of FELACS unveiled the impact of natural phenomena-induced anomalies on measured data, identified as outliers. The outliers disrupt data patterns and ranges, subsequently altering the optimal coding parameters for data samples, resulting in encoding and decoding errors. This study proposes a robust method for identifying and replacing outliers within sensor data, significantly enhancing compression performance. A reduction of variations in dataset patterns facilitated more accurate sampling and encoding of data. Consequently, fewer bits are required to encode data samples, rendering the algorithm energy-efficient and suitable for applications demanding error-free data recovery or meticulous error analysis. The proposed method was successfully applied to the modified ALDC algorithm, exhibiting efficient performance. An optimum block size of sampled data was discovered for Fishnet relative humidity deployment ensuring efficient transmission of environmental data real-world sensor network deployments like Fishnet, Lucerne, and Le Genepi. These findings underscore the potential for significant energy savings and improved data accuracy through adaptive lossless data compression techniques, making them valuable assets for applications with stringent energy constraints or demanding data integrity.