The ATC sector is on the cusp of a revolution that will transform how aircraft are managed in increasingly congested skies. At the forefront of this change is Viasat’s Iris program. Viasat, which acquired Inmarsat in 2023 believes Iris will play a key role in modernising ATM communications through satellite technology.
Iris is being rolled out first in Europe through the Iris service provider European Satellite Services Provider (ESSP), ANSPs and airline easyJet, and is set to enable more efficient and sustainable air travel in the coming decades. Ghislain Nicolle, vice president of air traffic services at Viasat says, “We are in one of the most exciting periods for our industry. Aircraft are becoming more digitalized and the introduction of Iris will expand what we already do successfully over the ocean to the continental airspace.”
Airspace capacity improvements
Iris represents a leap forward in ATM technology and is Viasat’s most significant ATC project to date. Development of Iris started in 2014 led by the European Space Agency (ESA). Viasat recently signed a contract with ESSP to provide Iris services in Europe. ESSP has since obtained the first pan-European EASA certificate to provide certified Datalink services.
Iris is designed to complement traditional VHF communications. Nicolle says, “VHF plays an essential role during aircraft approach or take-off phases by supporting voice communications and will remain the primary means of communication for this purpose. As ATC is globally deploying Datalink communications to supplement VHF voice, Iris provides the required performance needed to make this happen.”
The need for Iris is particularly acute in Europe, where VHF congestion is reaching critical levels. “Europe is facing a lot of VHF congestion issues,” Nicolle notes. “A key part of Iris’ purpose is to increase capacity in the airspace through the time-based management of each aircraft. It sounds simple, but it’s not because the separation requirements are smaller when flying domestically compared to oceanic airspace.”
Iris enables more precise tracking of aircraft positions and facilitates more robust data communications between pilots and controllers. This increased precision and reliability are crucial for implementing advanced ATM concepts like trajectory-based operations (TBO).
“To support such operations you need to have a robust communication infrastructure available,” Nicolle says. “There is nothing better today than VHF or VDL plus satellite communications. It is essential if we want to deliver more effective ATC capabilities
while supporting new types of operations and aircraft.”
Iris enables several benefits. It allows airlines to fly with fewer delays and reduces fuel consumption by optimising flight routes. Research by SESAR suggests that fuel savings of around 3% are possible through flight route optimization. When combined with other ATM improvements, savings of between five to 10% are possible, offering the aviation sector a significant opportunity to reduce CO2 emissions.
Rapid adoption
The rollout of Iris is progressing at at pace. “We have 20 ANSPs in Europe today that are supporting Iris flights. That’s almost everybody in Western Europe,” Nicolle reports. “We are extending or connecting the remaining ANSPs over the coming year, including Cyprus, Slovenia and countries in the Nordics.”
This rapid adoption is unprecedented in the ATM sector. “This is the first time I’ve seen such fast adoption at scale,” Nicolle says. “There are 250 aircraft ordered in Europe with Iris capability that will be delivered in the next two to three years.”
Viasat began supporting the first flights equipped with Iris satellite communications capabilities in January 2024 with easyJet. Data from the operation of these aircraft suggests good performance of the system.
Trajectory based operations
Iris is a crucial enabler for trajectory-based operations (TBO), a concept that promises to revolutionize airspace management. TBO allows for more dynamic and efficient routing of aircraft, reducing delays and improving overall system capacity.
“Today, flight plans are loaded in the systems in advance of the flight. With TBO, you can change your flight plan during the flight and fly the most optimal route, avoiding holding patterns and turbulence in a dynamic manner. Today’s technology simply does not provide that capability without human intervention and the risk of disrupting flight operations in Europe is real, potentially creating massive delays.”
The implementation of TBO requires robust communication links and advanced flight management systems. “You need a strong communication link, but on top of that, you need to have a flight management system overall that enables those TBO trajectories to be calculated on a dynamic basis,” Nicolle says.
Multilink for safety and redundancy
Another key concept in the evolution of ATM is multilink communications. Multilink can be explained most simply as having multiple links you can rely on to deliver communications and data links and from which a common set of benefits across applications can be gained.
The importance of Multilink lies in its capability to provide redundancy and resilience for safety-critical communications by combining the strengths of different communication technologies. “Each of the links individually is very strong, but when you bind them together, you get a stronger solution,” says Nicolle. “And when you’re talking about safety services, you want to make sure that you have the redundancy and resiliency that is required,” Nicolle says.
Multilink is also a key part of enabling future technical improvements in aviation and ATC. VDL is a component of Multilink but alone will be unable to support the introduction of things such as TBO and further ATM automation.
The size of the aviation sector is predicted to continue to increase over the next 20 years at a rate of 4.3% per year believes UN body ICAO. Capacity to handle this increase in flights, while providing Datalinks for enhanced operations and other technical improvements, means offloading bandwidth to satellite communications while “allowing VHF to do what it is best at – supporting local area TMA manoeuvres”, says Nicolle.
While Iris is currently focused on Europe, its potential extends globally. Several regions outside of Europe could benefit from using the technology now.
“There are places where VHF issues similar to Europe are arising especially around big airport areas where air traffic congestion is an issue,” says Nicolle.
In this context, Asia-Pacific, Middle-East and parts of the US are big areas of focus. “Asia-Pacific is quite similar to Europe. It is a very fragmented airspace, with lots of different countries and lots of different approaches. There are some very busy areas like Singapore, Japan, and some places in China and we are actively looking at expanding the TBO and Iris concepts to those regions.”
Challenges and coordination
Implementing these capabilities requires coordination between different ANSPs and stakeholders. Nicolle acknowledges this challenge, which is not a new one in ATC: “Provision of safety services is specific to each state. The different states are getting organized and coordinating efforts around ICAO, which is publishing standards and recommended practices.
“The implementation of capabilities requires investment, on the ground and in the air by airlines and ANSPs. Improving ATC is a complex undertaking with many stakeholders and takes time. But the payback will be more capacity to accommodate the increase in traffic predicted between now and 2040, and the freedom to operate as efficiently as possible.
As the aviation industry continues to evolve, Viasat is already looking ahead to the next generation of technologies. “We are starting to look at what the next technology could be,” Nicolle reveals. “There are lots of concepts being developed these days, and we are engaged in looking at what the next generation of our services could be.”
These could take the form of expanding services using hybrid models of GEO and LEO operation, even the possibility of space-based VHF and ADS-B services.
The forward-thinking approach extends to emerging sectors like uncrewed aviation. “We are very active in providing beyond visual line of sight services and integrating services into
the civilian space for Advanced Air Mobility (AAM),” Nicolle said. “If AAM fulfils its potential, we may need to integrate tens of thousands more air vehicles into civilian airspace.”
Nicolle envisions a convergence of technologies in the coming decades. “What we do in the AAM world will benefit the commercial aviation world and vice versa,” he predicts. “We think that communications are going to play more and more important roles in the provision and automation of air traffic services. And we believe that Iris is paving the way to that future.”
As air traffic continues to grow globally, the need for more efficient and sustainable ATM solutions becomes increasingly critical. Viasat’s Iris program, along with concepts like TBO and Multilink represents a significant step forward in meeting these challenges. With its ability to enhance communication, improve efficiency, and enable more dynamic airspace management, Iris is set to play a crucial role in shaping the future of aviation.
Nicolle says, “Air traffic has doubled in the last twenty years. In the late 1980s, we had two pilots and an engineer in the cockpit. That’s not the case today. If we had not implemented the improvements we have over the last 20 years, we would not be able to provide the number of flights we can today.
“ATC and flight automation have been in the planning for a long time and will enable more capacity and sustainability efforts. Now with the technology we are deploying today, we are in a position to support those advances.”