Resiliently Synchronizing SFN Networks: Combining Precise Time Signals from GPS and Longwave Radio Stations

This thesis introduces a novel hybrid approach to enhance the resilience of time synchronization within Single Frequency Networks (SFN), crucial for digital broadcasting systems. The traditional reliance on Global Navigation Satellite Systems (GNSS) exposes SFNs to vulnerabilities including geophysical phenomena like ionospheric variations due to solar activity fluctuations, and deliberate disruptions such as spoofing and jamming attacks. To address these vulnerabilities, this work integrates terrestrial longwave radio transmitters into the time transfer framework as a supplementary precise time signal source. By leveraging the stable and reliable nature of longwave signals, a dual-check mechanism is implemented, enhancing the SFN's reliability significantly. This integrated system provides a robust fallback, ensuring continuous operation even when GNSS services are compromised. Experimental validations confirm the effectiveness of this approach, demonstrating a reduction in time transmission errors and an enhanced resilience against spoofing and jamming within SFNs. The findings lay a foundation for future research and development in robust hybrid time synchronization technologies, offering a scalable and effective solution to safeguard critical infrastructure against single-source dependency risks.