Software management of power consumption in WSN based on duty cycle algorithms

In battery-operated nodes of a wireless sensor network, energy is a scarce resource that should not be wasted. During the recent years, energy efficient algorithms and protocols to maximize network lifetime have attracted the attention of many researchers. As the radio transceiver is one of the elements of the node that has higher power consumption, a typical approach to save energy is to minimize the period of time it is active. That can be achieved by introducing a duty cycle in which the node periodically enables its radio for a short time to later return to an idle state. In this paper, we discuss the importance of the duty cycle window size and present an expression to determine it according to the particularities of the IEEE 802.15.4 specification. But, to obtain a more accurate expression, we show that it is necessary to consider the characteristics of a noisy channel, especially in industrial applications, where interferences cannot be underestimated. The proposed technique tries to minimize electromagnetic pollution in order not to disturb the normal operation of other radio devices in the environment. The results of a real implementation are also presented and its efficiency discussed in terms of boundary conditions.