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

Benefit	Description
Global Coverage	Extends voice and data communication into oceanic, polar, and remote airspaces with no terrestrial coverage.
Improved Flight Efficiency	Real-time communications allow tighter aircraft separation, more direct routing, and reduced fuel consumption.
Enhanced Safety	Eliminates “dead zones” in air–ground communication, improving situational awareness and emergency response.
Uses Existing Equipment	Initial trials showed no need for onboard hardware changes — existing VHF radios can connect via satellite.
Cross-Sector Use	Applicable beyond aviation — maritime, remote land operations, IoT, and emergency communications.

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.

A-SMGCS (Advanced-Surface Movement and Guidance Control System) is the term used to describe a modular system made up of different functions, the objective of which is to meet the capacity demands of airports through the orderly, fast and safe movement of aircraft and vehicles, regardless of visibility, traffic density or airport complexity.

Reduced airport capacity, mainly due to adverse weather conditions, but also due to saturation of facilities, can lead to bottlenecks and heavy financial losses.

In response to the regulatory needs in this field, the International Civil Aviation Organisation (ICAO) has defined “Operational Requirements for A-SMGCS Systems”, the objective of which is to provide a documentary basis for the gradual introduction of this concept at those airports whose characteristics make it advisable, as well as for the development of the technological framework that will support the implementation of these systems.

For ICAO, A-SMGCS is the term describing ‘a modular system, composed of different functions to support the safe, orderly and expeditious movement of aircraft and vehicles at aerodromes under all circumstances with respect to visibility conditions, traffic density and aerodrome complexity, taking into account the required capacity under various visibility conditions’. This is therefore the evolution of the SMGCS.

SWIM consists of different layers. The layers that have been identified so far within the framework of SESAR are:

• Networks layer- physical pan-European wide area network along with the essential technical IT building blocks (e.g. transport protocols, firewalls, routers). PENS and Internet will likely be used.
• SWIM Technical Infrastructure layer containing technical (middleware) capabilities that a SWIM infrastructure will provide to all connected systems or that will be identified on those systems already providing such capabilities.
• ATM Applications layer containing the ATM application functionality that is SWIM-enabled. This encompasses both provider-side applications that furnish ATM service implementations, and consumer-side applications that make use of these remote services (through the infrastructure).

VoIP technology allows the implementation of the “Any Channel from any Sector from any Centre” concept:

• Distributed VCS: VCS nodes in WAN
• Global Configuration (all centres involved).
• Global on-line reconfiguration (all centres involved).
• On-line dynamic “sectors” definition.
• On-line resources allocation

VoIP technologies allow to begin to use the potential of having all integrated into a single network. For example:

• The intercommunication of VCSs in real time. Until now, VCSs are isolated entities and if it occurs, for example, a configuration change and / or a re-sectorization in one end, the another one does not know this fact. With the new technologies, VCSs can dialogue and learn about changes made ​​by the adjacent VCSs performing the corresponding operations (optimizing communications keys, etc..).
• Sharing of the radio sites resources. Currently, ACCs have assigned specific radio channels assigned to radio sites normally located within their FIR/UIR region of responsibility and interconnected by dedicated lines between them. Frequency channels and complete radio sites can be dynamically assign though the IP network from an ACC ’A’ to another ACC ‘B’. It would be possible to have a particular sector in an ACC or to move it, not only within the ACC but to another collateral ACC.

VoIP technology allows the implementation of the “Any Channel from any Sector from any Centre” concept:

• Distributed VCS: VCS nodes in WAN
• Global Configuration (all centres involved).
• Global on-line reconfiguration (all centres involved).
• On-line dynamic “sectors” definition.
• On-line resources allocation

VoIP technologies allow to begin to use the potential of having all integrated into a single network. For example:

• The intercommunication of VCSs in real time. Until now, VCSs are isolated entities and if it occurs, for example, a configuration change and / or a re-sectorization in one end, the another one does not know this fact. With the new technologies, VCSs can dialogue and learn about changes made ​​by the adjacent VCSs performing the corresponding operations (optimizing communications keys, etc..).
• Sharing of the radio sites resources. Currently, ACCs have assigned specific radio channels assigned to radio sites normally located within their FIR/UIR region of responsibility and interconnected by dedicated lines between them. Frequency channels and complete radio sites can be dynamically assign though the IP network from an ACC ’A’ to another ACC ‘B’. It would be possible to have a particular sector in an ACC or to move it, not only within the ACC but to another collateral ACC.

GAELICAM launches a new portfolio of CNS/ATM courses