Wake-Up Channel Selection for On-Demand WiFi Wake-Up Using WLAN Signals

In order to reduce energy wastefully consumed by WiFi device, Radio-On-Demand Networks (ROD) has been proposed, which offers wireless access in an on-demand manner. Each WiFi device in ROD is equipped with a low-power wake-up receiver which is capable of detecting the length of frames observed over WiFi channels through envelope detection and on-off-keying (OOK) processing. Once the wake-up receiver detects the predefined set of length of WiFi frames included in the wake-up signal transmitted by the other WiFi device, it turns its main WiFi module on. The wake-up receiver extracts WiFi signals over all WiFi channels at 2.4 GHz band. On the other hand, a WiFi device, which tries to wake up the other device, selects a wake-up channel, a channel to transmit its wake-up signal. In this case, the receiver observes an envelope which is the combination of the wake-up signal and the interfering signals existing over all WiFi channels. Here, how to select the wake-up channel is a key issue when the degree of interference is different among multiple WiFi channels. In this paper, with different degree of interference in each channel, we evaluate the impact of wake-up channel selection on the wake-up success probability of WiFi device. Besides simulations results, we also present experimental results which are obtained with our developed prototype of wake-up receiver.