Source coding technique for energy efficient IEEE 802.15.4 wireless sensor networks

One of the main issues in wireless sensor networks is energy efficiency. Most of the energy is used for wireless transmission. To reduce an amount of data being sent, if a particular compression algorithm is used, than it can significantly reduce a power consumption and increase node´s operating lifetime. Presented in this paper is a research, in which the possibility of use of IEEE 802.15.4 wireless sensor networks in electrocardiogram (ECG) monitoring applications is analyzed. ECG signal, measured from a patient heart, is in the first step compressed that uses Autoregressive (AR) predictive coding and then again, using Huffman´s entropy coding. It has been studied, through the use of simulations, how reduction in data rate of compressed data will affect node´s average power consumption. The results obtained from data compression of ECG signal show that sufficient energy saving can be achieved.