Harvesting a clock from a GSM signal for the wake-up of a wireless sensor network

This paper presents a low-power technique for harvesting a clock from the Global System for Mobile Communications (GSM) cellular network for the purpose of waking up and synchronizing nodes in a wireless sensor network. The 21-Hz clock is embedded within the broadcast channel of every GSM cell worldwide, making it a pervasive synchronization source. A low-power receiver architecture is presented to harvest the signal. Based on simulation results, the architecture can extract the clock with an error probability of less than 10^-4. Finally, a discrete prototype was built to verify the functionality of the receiver architecture.