How does Wi-Fi work on a plane and is it secure?

With the majority of customers now turning to their laptops, mobiles and tablets for entertainment and work on long-haul flights, it is perhaps no great surprise that some airlines have started allowing their passengers to connect to Wi-Fi while on board. Not only does this benefit those passengers who need to conduct business without interruption, it also offers comfort to loved ones who may be concerned about flight delays. So how does this technology work? Well, with a moving object, it is not as simple as your home Wi-Fi. Read on to find out more.

Hardware on board

To enable passengers to connect to the Wi-Fi in the airplane cabin, there are multiple Wi-Fi access points (WAPs). A large twin-aisle plane may have as many as six of these, while a standard charter has around two. From the WAP, the passenger’s connection is routed through an onboard server to a network off board. The goal is to make the passenger’s connection as seamless as possible as the aircraft moves through the sky. This works in the same way as if you were using your phone to stream while on a moving train.

Overland flights

There are two ways for an internet signal to reach your device at 35,000 feet. The first is via ground-based mobile broadband towers. Here the nearest tower sends signals directly up to an aircraft’s antennas to make the connection. These towers’ cells are much larger than those of the typical cell towers used for phones. As you travel into different sections of airspace, the plane automatically connects to signals from the nearest tower. This only works if your aircraft is flying overland as these towers don’t exist in the ocean.

The downside of this form of connection is that it only includes a limited spectrum. For instance, the bandwidth for the newest generation system is up to 9.8 megabits per second, per aeroplane (shared across all users). This is enough for email and casual web surfing but would get quickly exhausted if people stream video, so this is usually blocked.

Overseas flights

The second way Wi-Fi can be produced on aircraft over oceans is via satellite. Here, a plane’s antenna connects to close satellites in geostationary orbit (35,786km above the planet), which send and receive signals to earth via receivers and transmitters. These are the same satellites that are used in television signals, weather forecasting, and military operations.

A satellite connection offers around 12 megabits per second, per aeroplane, which is faster than Wi-Fi over ground-based towers. However, according to UK communications regulator Ofcom, the average UK household internet speed reached 28.9 Mbps in 2016 – so in-flight Wi-Fi has a long way to go to catch up with what we are more typically used to.

Why is in-flight Wi-Fi so slow?

Although onboard Wi-Fi technology is developing fast, it has struggled to keep up with the sophistication and number of devices passengers wish to connect. With countless apps, websites and services, there’s a much greater strain on resources. Satellites are also expensive to maintain and upgrade, so that technology is taking time to progress.

Why do I have to pay?

Adding antenna that allow for Wi-Fi capabilities on board can burden the aircraft by increasing drag. As a result, the company has to spend more for fuel. In addition, leasing the antennas on satellites is very expensive, so this cost is usually passed on to the airline and the passengers.

Is the Wi-Fi secure?

You should be aware that Wi-Fi networks on planes aren’t any more private than other public Wi-Fi networks. Just because you’re in the air, doesn’t mean that your data can’t be stolen. The only caveat is that the data thief has to be on the same flight. However, for those intent on stealing data transmitted over in-flight Wi-Fi, commercial airline flights are rife with opportunity.

For this reason, we strongly advise against using this Wi-Fi for anything other than browsing the web. Making any payments, either via online banking or via an online portal present significant risk for the individual, as does writing confidential emails.

If you do need to use the Wi-Fi on board, we recommend also using a VPN when on a public network, including on an aeroplane, your data is much better protected as it becomes encrypted. The other way to keep your data safe when on a plane is to invest in a privacy screen. Without it, the person in the seat next to you can read everything you’re working on.

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