Comparison between Preamble Sampling and Wake-Up Receivers in Wireless Sensor Networks

Having a wake-up receiver constantly listening is often seen as a replacement for running a duty- cycled medium access control protocol on a commercial low-power radio chip. Wake-up receivers do offer a better latency while consuming negligible power. Recent wake-up receivers show an impressively low power consumption of 52μW, but at the cost of a sensitivity of -72dBm, 20-30dB higher than the sensitivity of a commercial radio chip. This difference in sensitivity causes the wake-up receiver to have a much smaller communication range than the commercially available low power radio. In practice, this translates into requiring a denser deployment, or having to add an external power amplifier. This paper discusses the applicability of wake-up receivers in low-power wireless multihop networks. We show how, at available sensitivity levels, a wake-up receiver helps reducing the power consumption, but also requires a dramatically higher design or deployment cost.