How does WiFi on the aircraft work?

In recent years, the service of providing Internet on airplanes via WiFi connections is increasingly popular. Have you ever wondered, don't know how to get WiFi on the plane?

According to the explanation of a former employee of a solution provider in Quora, there are two main ways to provide on-board internet: satellite signals and grounding signals.

There are two ways for an airplane to connect to the internet: use ground signals (above) and satellite signals.

The main grounding signal is the signal directly connected between the aircraft and the ground antenna. Under the ground there will be a series of broadcast stations, like the BTS of a mobile service but much larger. The receiving antenna is placed under the belly of the aircraft, and when the aircraft flies over different regions, it will be connected by handoff between broadcast stations, much like a mobile phone. Users will not feel latency when roaming.

The downside of this technology is its relatively slow speed.

The installation of broadcast stations by this method is much cheaper than using satellites, but there are restrictions on speed and geography. The current maximum speed, such as Gogo's ATG4 service, is only 9.8 Mb / s shared to all passengers. With this speed, users can only check email or surf the web gently but it is difficult to watch online videos. In addition, broadcast stations are located on the ground so this form is not available for transcontinental flights. Internet signaling grounding is mainly applied to US domestic flights, currently equipped with about 1000 aircraft.

Satellite signals are a method of using satellites to fly around the ground to broadcast airplanes. The orbits of the satellites are about 16,000 kilometers from the ground, and the waves are collected through antennas located on the fuselage. Currently the best solution delivers speeds of about 20 - 40 Mb / s for each aircraft, depending on the number of aircraft in use within the satellite's range. In the near future satellites broadcasting Ka band may bring higher speed.

A technician is installing a satellite connection on a Boeing 747.

In addition to high speed, satellite signals are the only way to provide internet for ocean flights. When flying, the antenna on the aircraft will automatically change the direction to connect to the satellite, and when the flight is too far, it can be converted to signals from other satellites.

The method of using satellite signals has two drawbacks . First , the latency will be higher because the signal must pass through the satellite at a height of more than 10,000 km, and the process of connecting to other satellites will also cause the connection to be affected rather than as a roaming between the stations. The second drawback is the much higher price, because the satellite rent is already very high. This leads to very expensive internet prices on airplanes.

On the plane, the device to access WiFi (WiFi access points or WAP) will broadcast to the phone, laptop . of the user. The number of WAPs depends on the size of the aircraft. Large aircraft can have up to 6 WAPs. Previously when WiFi was not popular, even the aircraft had an Ethernet port to plug the computer, but now WiFi is enough for most users.