Citation:
Elsts, A., Fafoutis, X., Duquennoy, S., Oikonomou, G., Piechocki, R., Craddock, I. (2018). Temperature- Resilient Time Synchronization for the Internet of Things. IEEE Transactions on Industrial Informatics, 14(5), pp. 2241-2250.
Sponsor:
This work was performed under the SPHERE IRC funded by the
UK Engineering and Physical Sciences Research Council (EPSRC), Grant
EP/K031910/1. It was also partly funded by the European Union’s Horizon
2020 research and innovation programme under grant agreement No
761586 (5G-CORAL), the distributed environment Ecare@Home funded by
the Swedish Knowledge Foundation, and by a grant from CPER Nord-PasdeCalais/
FEDER DATA.
Networks deployed in real-world conditions have to cope with dynamic, unpredictable environmental temperature changes. These changes affect the clock rate on network nodes, and can cause faster clock de-synchronization compared to situations where devices are Networks deployed in real-world conditions have to cope with dynamic, unpredictable environmental temperature changes. These changes affect the clock rate on network nodes, and can cause faster clock de-synchronization compared to situations where devices are operating under stable temperature conditions. Wireless network protocols such as Time-Slotted Channel Hopping (TSCH) from the IEEE 802.15.4-2015 standard
are affected by this problem, since they require tight clock synchronization among all nodes for the network to remain operational. This paper proposes a method for autonomously compensating temperature-dependent clock rate changes. After
a calibration stage, nodes continuously perform temperature measurements to compensate for clock drifts at run-time. The method is implemented on low-power IoT nodes and evaluated through experiments in a temperature chamber, indoor and
outdoor environments, as well as with numerical simulations. The results show that applying the method reduces the maximum synchronization error more than 10 times. In this way, the method allows reduce the total energy spent for time synchronization,
which is practically relevant concern for low data rate, low energy budget TSCH networks, especially those exposed to environments with changing temperature.[+][-]