What Is “Satellited-based VHF Voice and Data”?

• The VHF (Very High Frequency) band for aeronautical use typically covers 117.975 MHz to 137 MHz, used for pilot–controller voice communications and air–ground data links.
• Traditionally, these communications rely on ground-based stations (line-of-sight). Over oceans, polar regions, or remote areas, coverage can be very limited or nonexistent.
• Satellite-based VHF means using satellites (usually LEO – Low Earth Orbit) as relays for VHF signals, enabling voice and data communications even where no ground station exists.
• This technology allows global communication services for aviation, maritime, and other remote operations using existing or slightly modified VHF radio equipment.

 Major Recent Developments:

1. Startical / ECHOES (Europe)

• Startical (a joint venture by ENAIRE and Indra) achieved the world’s first real-time voice communication between a pilot and an air traffic controller using satellite VHF.
• Later, it also achieved the first data transmission (VHF datalink) via satellite between an aircraft and air traffic control.
• Their first demonstrator satellite, IOD-1, was launched in March 2025, equipped with a 3-meter deployable VHF antenna. Tests were successfully carried out over the Atlantic Ocean.
• The ECHOES project, co-funded by the European Union through SESAR Joint Undertaking, aims to deploy a constellation of more than 200 LEO satellites to provide global VHF coverage for aviation.
• In December 2023, the International Telecommunication Union (ITU) officially allocated the 117.975–137 MHz VHF band for aeronautical mobile-satellite (route) service – AMS(R)S, paving the way for these satellite systems.

2. Skykraft (Australia)

• Skykraft successfully tested space-based VHF communications for Air Traffic Management (ATM) over southern Australia.
• Their planned constellation also exceeds 200 satellites, providing VHF voice, VHF data, surveillance, and multilateration services for air traffic management.

Why It Matters

🔹 Technical and Regulatory Challenges

• Large Constellations Required – Continuous global VHF coverage requires hundreds of LEO satellites.
• Regulatory and Standardization Work – Although spectrum allocation is complete, operational and certification standards are still being developed.
• System Integration – Compatibility with existing VHF ground networks and avionics must be assured.
• Economic Viability – High deployment costs must be justified by efficiency and safety benefits.
• Technical Complexity – Antenna deployment, signal latency, interference, and Doppler correction challenges.

🔹 Current Status and Next Steps

🔹 Key Applications

• Aviation – Satellite-based VHF voice and data links for pilot–controller communications, ADS-B surveillance, and datalink messaging across oceans.
• Maritime – VDES satellite systems for two-way ship communications and data transfer.
• Remote Land Operations – Emergency services, mining, exploration, and scientific expeditions.
• IoT and Low-Bandwidth Connectivity – Possible lightweight data applications in extreme or isolated environments.

🔹 Practical Takeaways

• Operators and airlines should track commercial rollout plans (still in demonstration phase as of 2025).
• Existing avionics may already be compatible, but certification standards are being finalized.
• Regulatory bodies are integrating satellite VHF into air traffic management architectures.
• Radio enthusiasts and engineers should note that satellite VHF links reuse traditional frequencies (117.975–137 MHz), representing a new paradigm in the RF landscape.