Accuracy over energy metrics for evaluating sensor network MAC protocols

We describe a class of metrics which relate the accuracy of a sensor network measurement one achieves when using a certain MAC protocol with the energy the MAC protocol consumes. To measure accuracy we compare the true values of the physical phenomena and the values reconstructed at the sink. We propose three ways to compare them, the difference between the function of the physical phenomena and the function reconstructed at the sink, the mutual information of the true values and the values at the sink, and the coefficient of correlation between these values. We evaluate the metrics in a sensor network testbed, comparing the two MAC layer protocols B-MAC and RandMAC. The latter is a protocol developed in this work. It achieves lower energy consumption at the expense of transmission success rate.