A sub-μs accuracy GPS alternative using electrical transmission grids as precision timing networks.

Area of Science:

• Electrical Engineering
• Communications Engineering
• Network Security

Background:

• Over-reliance on Global Navigation Satellite System (GNSS) for time synchronization poses a significant risk to critical infrastructure.
• A robust alternative to GNSS is essential for maintaining societal functions during potential outages or attacks.

Purpose of the Study:

• To propose and validate a novel time dissemination method over national power transmission and distribution networks.
• To provide a resilient and secure alternative to GNSS for time synchronization in smart grid applications.

Main Methods:

• Utilizing existing power line carrier technology bandwidth and coupling with chirp Spread Spectrum modulation for time signal transmission.
• Implementing a correlation algorithm for time-of-flight estimation and correction during GNSS outages.
• Developing an FPGA prototype for experimental validation and performance assessment.

Main Results:

• Simulations demonstrate sub-microsecond timing accuracy on large transmission networks, even with low signal-to-noise ratios and impulsive noise.
• Experimental results confirm sub-microsecond accuracy for time dissemination over 700 meters using an FPGA prototype.
• Averaging techniques show potential for extending the system's range to a national scale.

Conclusions:

• The proposed power line-based time dissemination system offers a viable and secure alternative to GNSS.
• The technology provides high timing accuracy suitable for smart grid applications and is invulnerable to common wireless threats.
• This method enhances the resilience of critical infrastructure by mitigating GNSS dependency.