A prototype low-cost wakeup radio for the 868 MHz band

In many wireless sensor network scenarios, battery-powered nodes must operate for years, which necessitate the need for advanced power management of the radio. In this paper, we pursue the idea of using a second, ultra low-power radio that can be used to trigger a remote interrupt, so that a receiver can fire up its primary radio to engage in efficient high-speed communication with the sender. Wakeup radio avoids the complex bookkeeping associated with energy-efficient MAC protocols, but at the price of additional hardware. We present the first design of a low-cost wakeup radio made out of standard components. Our working prototype implementation operates in the European license-free 868 MHz band, and includes a specialised low-power microcontroller filtering out interference (e.g. GSM signals), which makes it practical for use in many real-world settings.