Image: Angélica Geisse

The first airborne Li-Fi-enabled data network is set to fly this fall, bringing even greater competition to the onboard connectivity space.

Let there be light!” Air France seems to be saying with its new Li-Fi-based in-flight entertainment (IFE) solution. In September, the airline will become the first to operate a commercial flight with a light-based data network, with the installation of hardware from Latécoère Group on an Airbus A321. The system will offer multimedia data throughput that the carrier says could soon be 100 times faster than existing Wi-Fi systems.

Demonstrations of Li-Fi capabilities on the ground are just a few years old, but the technology is advancing rapidly with aims to best Wi-Fi on weight, reliability and cost, in addition to performance. Testing in the controlled environment of a mock-up cabin is relatively easy though – transitioning that to a flying aircraft is more difficult. But Latécoère and Air France Industries KLM Engineering & Maintenance say it’s possible. After all, the certification process is far simpler than that needed for traditional Wi-Fi systems.

“It is only natural that Air France is investing in innovative solutions that will provide new experiences for our customers in a few years’ time.” – Antoine Laborde, Air France

To implement this new solution, a plastic shell containing the Li-Fi modem transceiver and a user-facing tablet is slid over existing headrests and is connected to in-seat power, minimizing the wiring necessary to bring the kit on board. Meanwhile, the access point sits in the overhead passenger service unit (PSU) console, with the transceiver connected to a headend via fiber-optic cables. Each seat has its own data flow, allowing for dedicated bandwidth to the displays.

Image: Latécoère

By using fiber and not heavier copper wiring, the system saves significant weight over a traditional Wi-Fi or embedded IFE installation, according to Serge Bérenger, Latécoère’s SVP Innovation and R&T. At the same time, Bérenger notes, Li-Fi can integrate into existing cabin network infrastructure, offering the same interface as traditional Wi-Fi systems.

To demonstrate the capabilities of the Li-Fi system, Air France and Latécoère have chosen an activity that requires high transmission speeds. In partnership with video game company Ubisoft, the airline will host an esports tournament in flight. The Li-Fi-powered gaming experience of TrackMania was previewed in a mock cabin at the Paris Air Show in June. Early stages of the official competition took place a few weeks later on the ground, but the final elimination rounds are slated to be played in the sky in September.

Antoine Laborde, Air France’s head of Innovation, is keen to see how the trial plays out, noting the potential future implications: “In-flight entertainment is a cornerstone of Air France’s onboard experience, and so it is only natural that Air France is investing in innovative solutions that will provide new experiences for our customers in a few years’ time.”

Latécoère isn’t the only vendor working in the Li-Fi space, nor is in-seat entertainment the only market for the solution. Astronics Product Development Technologies (PDT) is also working with the technology to find practical applications that benefit industry stakeholders. At this year’s Aircraft Interiors Expo, the company demonstrated a concept for IFE data loading that aims to replace the “sneakernet” solution still used so often today.

With the Astronics concept, a Li-Fi transceiver installed in an aircraft’s cargo area is able to transmit data while it is parked at the gate. A second transceiver is installed either permanently at the gate or, to bring more flexibility, on a belt loader or other ground-service vehicle. Some manual effort remains in this scenario, but it dramatically reduces aircraft touch time for technicians during data updates.

Image: Eduardo Leblanc

One significant advantage of the Li-Fi option for data transfer is that technicians can literally see the movement. Nick Cucci, head of Business Development, Astronics PDT, describes it as “hyperfast Morse code” that can be delivered using the same LED light that is already in the PSU console for passengers. But onboard Li-Fi systems will likely operate with infrared light so as not to disturb passengers. In an external-use case, however, a visible light spectrum could be very useful. Seeing the Li-Fi light turned on would allow a ramp driver to ensure data loading is occurring while bags are being handled, for example.

Li-Fi signals cannot traverse walls and other surfaces, meaning a direct line of sight is needed for the technology to work at an optimal rate. While this arrangement may be a challenge for personal electronic devices (PEDs) due to free movement and obstacles in an aircraft cabin, Cucci notes, it’s an advantage for bulk data loading or gate links. “Given Li-Fi’s really high speeds and directionality – and it being less susceptible to hacking – you could download a terabyte of [stored content] to the plane and offload all the smart aircraft information in seconds.”

Since Li-Fi data transmission requires a much shorter range than Wi-Fi and is less vulnerable to interception, it is a strong player for more important data channels such as flight-deck services. As Birger Timm, managing director of LED Lighting Systems at aeroLiFi, a German company betting that Li-Fi is the next frontier of in-flight connectivity, notes, “You have to get between the light source and the receiver. In an aircraft, that effectively means you need to be sitting on someone’s knee, and that’s very noticeable. In fact, Li-Fi is so secure that it is already being looked at for use in the cockpit for flight-critical applications.”

While Air France’s announcement is promising, proponents of Li-Fi solutions are not slowing down to celebrate. Rather, they are focused on continuing at the same brisk pace to further develop systems they’ve been working on in recent years. In early 2018, Li-Fi systems offered speeds in the 10–50 Mbps range. Today’s models are capable of 100 Mbps, and in the coming months, speeds of multiple gigabits per second are expected. Moreover, the technology is being encoded onto custom microchips, keeping costs, size and power consumption down, even as newer models continue to shrink.

“Li-Fi is so secure that it is already being looked at for use in the cockpit for flight-critical applications.” – Birger Timm, aeroLiFi

Wi-Fi providers can deliver connectivity throughout a space because radio waves do not require a line of sight. A single Li-Fi access point cannot deliver that same coverage, but a network of lights can get very close. Connect reading lights with an LED ceiling panel, for example, and the ability to keep a device connected via Li-Fi as it moves throughout the cabin would expand significantly. With such lighting panels under development by companies like Safran and Collins Aerospace, this idea could fly soon.

As Li-Fi hardware evolves, one can expect shrinking systems and higher bandwidth, such that it could be included in personal devices rather than only in custom seat mounts or external dongles.When this comes into play, Latécoère’s Bérenger anticipates delivering entertainment and connectivity not only to seatbacks but also to PEDs. Cucci is similarly expecting Li-Fi hardware to sit alongside a Wi-Fi modem in a device. He describes the disappearance of the dongle as an eventual goal.

Bérenger believes that the push for 5G network performance will help the industry adopt Li-Fi technology. “The objective of 5G is to guarantee a quality of service as opposed to 4G, which is a promise of bandwidth. It will be absolutely essential for a PED to be always connected to an access point, and the modems are already very close to each other in technology,” he says. “The next generation of PEDs will be Li-Fi-ready because it is necessary for 5G, and once they are, we can take full advantage of this infrastructure with no changes on board.”

“Light Show” was originally published in the 9.4 September/October issue of APEX Experience magazine.