Three stage wakeup scheme for sensor networks

Crucial for limiting power consumption of the nodes in sensor networks is a strategy of keeping the nodes in sleep a mode most of the time. Consequently, the strategy of when and how to reactivate them is a key issue to let sensor networks become reality. This paper presents a special wakeup receiver for this task which utilizes a concept of two successive stages of different complexity and power consumption. Always on will only be a very simple stage consuming nW, this will activate a slightly more complex stage consuming some μm, and only if this stage confirms a valid wakeup condition the main transceiver is activated.