Hardware Assisted Clock Synchronization for Real-Time Sensor Networks

摘要: Time synchronization in wireless sensor networks is important for event ordering and efficient communication scheduling. In this paper, we introduce an external hardwarebased clock tuning circuit that can be used to improve significantly reduce drift over long periods of time without waking up the host MCU. This accomplished through two main hardware sub-systems. First, upon presented [1] synchronizes clocks using ambient magnetic fields emitted from power lines. The new uses electric field front-end as opposed original magnetic-field sensor, which makes design more compact, lower-power, lower-cost, exhibit less jitter improves robustness noise generated by nearby appliances. Second, present a low-cost continuously trim micro-controller's low-power at runtime. Most approaches require CPU periodically adjust internal counters accommodate drift. Periodic discrete updates interpolation errors compared continuous update they expend energy during these wake periods. Our hardware-based allows remain deep-sleep mode extended while compensates We show our consumes 60% than able correct rates within 0.01 ppm hungry expensive precision clocks.