How Does Wi-Fi Work on Airplanes?

Whether or not you're flying right now, you may have wondered how you're able to get work done on your laptop or play games on your phone all the way up above the clouds. Many airlines offer Wi-Fi to allow passengers to entertain themselves as they soar through the sky, but where does this internet connection come from and how does it work? Airplane Wi-Fi actually comes from two different sources, which may change throughout the course of a flight depending on location and altitude.

Here, we asked a technology expert for details.

Understanding Wi-Fi Sources on a Plane

The first source of Wi-Fi on an airplane is an air-to-ground (ATG) network. "It involves an airplane antenna connecting to cell towers on the ground, much like the way your cell phone gets Wi-Fi," explains Jonathan S. Weissman, senior lecturer in the department of computing security at the Rochester Institute of Technology. "The plane serves as a hotspot as it connects to various cell towers as the flight progresses." The signal will likely jump around during a flight. If the plane is over an area with plenty of cell towers, however, the connection could be consistent enough for getting work done.

But the plane's antenna cannot reach cell phone towers when it goes over water. So, how do passengers get Wi-Fi in that case? This is when the other method of getting Wi-Fi kicks in. "The second source involves an airplane antenna connecting to geostationary orbiting satellites that are connected to ground stations," says Weissman. This antenna is the fallback for when ATG is unavailable. As a result, passengers are able to connect to the internet even when on a long-distance transatlantic flight.

How to Make a Secure Connection

Airplane Wi-Fi is a wonderful convenience, but there are a few safety concerns passengers do need to be aware of: Public Wi-Fi at the airport gym, coffee stand, or cafeteria is considered risky—and so is the Wi-FI available on the airplane. "The stakes are even higher on a plane, because malware on websites browsed by passengers could give hackers from anywhere in the world the ability to access a plane's systems," says Weissman. Remember that the signal passengers use is bouncing from cell tower to cell tower.

Staying secure requires a few additional steps. Of course, passengers should make sure that they have updated devices with anti-virus software. Weissman also recommends using a Virtual Private Network (VPN), which your employer may provide for you. Regular users can also sync their own VPNs with OpenVPN or Algo VPN, or use a VPN service like NordVPN and FireFoxVPN. You want to research the VPN to check for its logging activities and privacy practices. In general, a paid VPN has more privacy than a free VPN that serves you advertisements.

Abiding by Laws

Another thing to keep in mind when using airplane Wi-Fi is location. Just because a plane is in the sky does not mean that the countries the aircraft is flying over will not have a problem with what passengers are accessing on their channels. "If you access content prohibited by a country while in their airspace, you could be thrown in prison," warns Weissman. The problem is that passengers may not know that their internet usage has been flagged by another country until they visit the area. So, how should can a passenger protect themself? Know the flight plan and which countries a flight will be flying over, then research their internet laws. Depending on what a passenger wants to do online, it may be better to not access the internet at all on a flight.