Measurements of energy consumption and execution time of different operations on Tmote Sky sensor motes (carried out as a research during Master’s level – Masaryk University)
In order to provide WSNs with security, additional energy is required. With limited energy source of sensor motes, we should balance the level of security and energy consumption. To find this trade-off, the amount of energy consumed by different components on sensor motes while running security algorithms should be known. Conducting some measurements to estimate the energy consumption and execution time of different operations on a Tmote Sky sensor mote was my responsibility in this work. For the IEEE 802.15.4 compliant radio transceiver of Tmote Sky (CC2420), different frame structures and CSMA/CA medium access mechanism of this standard were investigated to discover the overhead of channel acquisition, header and footer of data frame, and transfer reliability during packet transmission. The implementation of this standard in TinyOS, a popular operating system widely used in WSNs, was also taken into consideration. Per-packet power consumption was used in a mathematical model estimating the lower and upper bounds of routings in the network. Energy consumptions in different power states of the microcontroller of Tmote Sky, MSP430, and to transfer data from/to ST M25P80, the external flash memory of Tmote Sky, were also measured.