Using Feedback Control within WSN´s to meet Application Requirements

Currently the main approach used to save power within WSN´s is to employ reactive MAC schemes that detect when the network is becoming busy and adapt to provide an increase in available bandwidth. Once the traffic becomes lighter the available bandwidth is reduced to save power. While this works well with bursty sporadic traffic, there is a clear trade-off between latency of response and power savings. Other problems with this approach include hard to derive parameters along with their poor performance in periodic sense-and-send applications due to their reactive nature. We propose an adaptive feedback-based scheme that adjusts the duty cycle of the the motes to reduce the power consumed in typical sense-and-send applications by 58.4%, while still meeting a minimal level of service specified by the operator. Such an adaptive scheme is necessary to minimise power consumption as the complete network characteristics are unknown prior to deployment, and can change during runtime. Our approach is independent of node distribution and is also MAC layer agnostic, unlike the current state-of-the-art, whilst consuming less power. Our approach provides a simple method for the application designer to modify its behaviour, whilst allowing WSNs to operate longer and provide the same level of service as current approaches.