Benefits of wake-up radio in energy-efficient multimodal surveillance wireless sensor network

Scarce energy budget of battery-powered wireless sensor nodes calls for cautious power management not to compromise performance of the system. To reduce both energy consumption and delay in energy-hungry wireless sensor networks for latency-restricted surveillance scenarios, this paper proposes a multimodal two-tier architecture with wake-up radio receivers. In video surveillance applications, using information from distributed low-power pyroelectric infrared (PIR) sensors which detect human presence limits the activity of cameras and reduces their energy consumption. PIR sensors transmit the information about the event to camera nodes using wake-up radio receivers. We show the benefits of wake-up receivers over dutycycling in terms of overcoming energy consumption vs. latency trade-off (proved with two orders of magnitude lower latency – only 9 ms). At the same time, the power consumption of the camera node including a wake-up receiver is comparable with the one having only duty-cycled main transceiver with 1% duty cycle (about 32 mW for 25 activations per hour).