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LDACS

The digital revolution is coming

LDACS (L-band Digital Aeronautical Communications System) will introduce efficient broadband data communications to aviation, enhancing security, safety and resilience. As a key player in the development of LDACs, Frequentis is both building the technology and helping to validate its real-world usage. By supporting concepts such as 4D trajectory-based operations, LDACS will help ANSPs and airlines to increase their capacity and operational efficiency.

 

Growing demand for data services

Efforts to modernise air traffic management (ATM) usually involve the sharing of increased volumes of data between aircraft and control centres. Indeed, innovations such as trajectory-based operations or increased automation in navigation are currently held back by the inability of existing HF and VHF data links to deliver the required bandwidth. As air traffic continues to grow, the industry needs more spectrum-efficient technology to enable the transition from analogue voice to digital data links as the primary means of communication. And the challenge is not limited to bandwidth: the future communication infrastructure also requires better security, safety and mobility.

 

What is LDACS?

LDACS (L-band Digital Aeronautical Communications System) is a new standard for air-to-ground communication that enables modern broadband IP-based data communications. Based on a cellular communication concept, LDACS is a digital broadband radio link between aircraft and ground systems, enabling the secure and spectrum-efficient exchange of data for communication, navigation and surveillance. LDACS offers adaptive performance based on the current demand in each cell, such that the available resources can be efficiently shared between all aircraft.

As a future open standard of the International Civil Aviation Organization (ICAO), LDACS is a protected L-band with AM(R)S allocation exclusively for use in aviation. It is adapted to suit the high-speed, wide-coverage requirements of aeronautical communication, and uses state-of-the-art OFDM technology with efficient coding and adaptive modulation to achieve data rates of between 0.5 and 2.6 Mb/s. With its decentralised and distributed architecture, LDACS has no single point of failure, making it resilient enough to support growing complexity in the skies. Integrated quality-of-service enables LDACS to prioritise safety-critical communication, while built-in cybersecurity measures such as mutual authentication help to ensure secure and reliable transmissions.

Since digital voice channels are completely independent of the physical LDACS infrastructure, a single ground station can serve multiple ATC voice sectors and a single ATC voice sector can be served by multiple ground stations. This means that LDACS facilitates sector planning and re-sectorisation, and enables new voice concepts such as flight-centric operation.

 

How is Frequentis involved?

Frequentis has been heavily involved in LDACS from the beginning, and we continue to play an active role in bringing this new technology into real-world operations. In addition to providing LDACS-ready radios and radio access infrastructure, including technologies around mobility, security and quality-of-service, Frequentis has developed a full LDACS ground infrastructure and an LDACS testing field with permanent installation at three radio sites. Using this infrastructure, we have completed flight trials and end-to-end validation for new digital voice services.

Our trial LDACS implementation provides end-to-end IPv6 connectivity between airborne routers and ground networks, and mobility technologies to enable seamless handovers between ground stations as aircraft move between LDACS cells.

 

What does the LDACS-enabled future look like?

The ability to exchange higher volumes of data between ground systems and aircraft will facilitate several innovative concepts such as sectorless flight and 4D trajectories. The sectorless flight concept assigns multiple aircraft to a single controller for the entire duration of their flight, eliminating the need to perform handovers and thereby increasing controller capacity and efficiency. The 4D trajectory concept aims to optimise aircraft trajectories in the usual three dimensions (latitude, longitude and altitude) as well as in time, so that aircraft arrive at their destination at the planned time. Both concepts have the potential to drive significant savings in fuel and reductions in emissions.

For Frequentis, LDACS is one of several important building blocks in the digital transformation of the aviation industry. Our vision is to support our customers and partners on their journey to the future, and as with all such initiatives, we are developing stepwise deployment methodologies that will reuse your existing infrastructure wherever possible. For more information on how to benefit from LDACS, contact us today!

 


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LDACS flight trials (L-band Digital Aeronautical Communications System)

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