Low-Power Wake-Up Radio for Wireless Sensor Networks

Power consumption is a critical issue in many wireless sensor network scenarios where network life expectancy is measured in months or years. Communication protocols typically rely on synchronous operation and duty-cycle mechanisms to reduce the power usage at the cost of decreased network responsiveness and increased communication latency. A low-power radio-triggered device can be used to continuously monitor the channel and activate the node for incoming communications, allowing purely asynchronous operations. To be effective, the power consumption of this wake-up device must be on the order of tens of microwatts since this device is always active. This paper presents our first attempt at designing such a low-power receiver. Very few realizations of wake-up devices are reported in the literature and none presents power dissipation below 40 mu W. Our design implements a complete wake-up device and initial results indicate an average power consumption below 20 mu W, which is more than 2 times lower than other reported devices.