Optimizing MAC Layer Performance for Wireless Sensor Networks in eHealth

Efficient selection of MAC parameters in Wireless Sensor Networks (WSNs) improves the network performance by reducing energy consumption and increasing network lifetime. This paper describes the importance of efficiently selecting threshold parameters on the performance of MAC protocol for dynamic traffic applications such as eHealtchare. The asynchronous Adaptive & Dynamic Polling MAC protocol (ADP-MAC) has been used for the analysis. ADP-MAC uses the statistical measure of Coefficient of Variation (CV) as a threshold parameter for selecting channel polling interval distribution. Considering the medical applications, Poisson and bursty arrivals have been assumed in this work. Energy & delay performance of ADP-MAC has been studied for the varying values of CV. Experiments have been performed on Mica2 testbed using Avrora emulator. It has been observed that low values of CV results in better energy performance for Poisson traffic, whereas high value should be selected for CBR traffic. The performance of ADP-MAC for bursty arrivals for varying values of CV depicts nearly a constant trend. Based on the analysis presented in this paper, the medical applications of WSN can be facilitated.