TY - GEN
T1 - On the accuracy of network synchronization using persistent hourglass clocks
AU - Curuk, Eren
AU - Yildirim, Kasm Sinan
AU - Pawelczak, Przemysaw
AU - Hester, Josiah
PY - 2019/11/10
Y1 - 2019/11/10
N2 - Batteryless sensor nodes compute, sense, and communicate using only energy harvested from the ambient. These devices promise long maintenance free operation in hard to deploy scenarios, making them an attractive alternative to battery-powered wireless sensor networks. However, complications from frequent power failures due to unpredictable ambient energy stand in the way of robust network operation. Unlike continuously-powered systems, intermittently-powered batteryless nodes lose their time upon each reboot, along with all volatile memory, making synchronization and coordination difficult. In this paper, we consider the case where each batteryless sensor is equipped with a hourglass capacitor to estimate the elapsed time between power failures. Contrary to prior work that focused on providing a continuous notion of time for a single batteryless sensor, we consider a network of batteryless sensors and explore how to provide a network-wide, continuous, and synchronous notion of time. First, we build a mathematical model that represents the estimated time between power failures by using hourglass capacitors. This allowed us to simulate the local (and continuous) time of a single batteryless node. Second, we show through simulations the effect of hourglass capacitors and in turn the performance degradation of the state of the art synchronization protocol in wireless sensor networks in a network of batteryless devices.
AB - Batteryless sensor nodes compute, sense, and communicate using only energy harvested from the ambient. These devices promise long maintenance free operation in hard to deploy scenarios, making them an attractive alternative to battery-powered wireless sensor networks. However, complications from frequent power failures due to unpredictable ambient energy stand in the way of robust network operation. Unlike continuously-powered systems, intermittently-powered batteryless nodes lose their time upon each reboot, along with all volatile memory, making synchronization and coordination difficult. In this paper, we consider the case where each batteryless sensor is equipped with a hourglass capacitor to estimate the elapsed time between power failures. Contrary to prior work that focused on providing a continuous notion of time for a single batteryless sensor, we consider a network of batteryless sensors and explore how to provide a network-wide, continuous, and synchronous notion of time. First, we build a mathematical model that represents the estimated time between power failures by using hourglass capacitors. This allowed us to simulate the local (and continuous) time of a single batteryless node. Second, we show through simulations the effect of hourglass capacitors and in turn the performance degradation of the state of the art synchronization protocol in wireless sensor networks in a network of batteryless devices.
KW - Hourglass clocks
KW - Intermittent computing
KW - Sensor networks
UR - http://www.scopus.com/inward/record.url?scp=85076605646&partnerID=8YFLogxK
U2 - 10.1145/3362053.3363497
DO - 10.1145/3362053.3363497
M3 - Conference contribution
T3 - ENSsys 2019 - Proceedings of the 7th International Workshop on Energy Harvesting and Energy-Neutral Sensing Systems
SP - 35
EP - 41
BT - ENSsys 2019 - Proceedings of the 7th International Workshop on Energy Harvesting and Energy-Neutral Sensing Systems
PB - ACM
T2 - 7th International Workshop on Energy Harvesting and Energy-Neutral Sensing Systems, ENSsys 2019, co-located with ACM SenSys 2019
Y2 - 10 November 2019
ER -