How does airplane WiFi work?

Aircraft Nerds Store

HOW DO SOME AIRLINERS OFFER WI-FI IN FLIGHT


How does airplane wifi works

As a passenger of a commercial aircraft, where you are travelling at a height of almost 37,000 feet and with a speed of 500 miles per hour you are too far from cell tower to receive any signal but there are some modern airliners which would help you to deal with this problem by providing in-flight Wi-Fi to keep you entertained throughout your journey. This article deals with different ways of getting an in-flight Wi-Fi connection.

AIR TO GROUND TRANSMISSION (ATG):

There are mainly three different ways of getting an in-flight Wi-Fi, which differ from each other in bandwidth and internet speed. ATG system requires two antennas to be placed at the bottom of the aircraft, which receives signals from the ground-based cell tower. When ATG system is activated, the aircraft starts receiving signals from different cell towers and these signals are then provided to the passengers via Wi-Fi router.   
The disadvantage of using ground-based cell tower to receive signal is slow internet speed and internet instabilities. Passengers would not be able to use Wi-Fi while the aircraft is cruising over a sea or where the cell towers are not available. The speed offered by ATG is about 3 megabytes per second while a mobile equipped with 4G LTE system could provide speeds up to 35 megabytes per second.

KU-BAND SERVICE:

This is a satellite-based technology which could provide internet speeds of up to 50 megabits per second. K stands for a German word “Kurz”, which means short. Here in this context it actually means shortwave frequency. U means that the frequency is lying “Under” the original NATO K-Band frequency range. Original NATO K-Band frequency lies between 20 to 40 GHz. A ground-based transmitter is used to send the signal to the satellite which is received by a special aircraft antenna, after being reflected from the satellite.
Airplane server decodes this signal and then distributes it with the passengers via the Wi-Fi router. If a large commercial aircraft like Boeing 737 or Airbus A320 is considered, where about 150 passengers would like to access Wi-Fi at the same time then this system would still be relatively slow. The problem of time delay arises as the signal has to travel to a large distance. If there are many aircraft transmitting on the same satellite then the internet speed would definitely go down.

KA-BAND SERVICE:

It is also a satellite-based system which uses frequency in the upper region of the native frequency i.e. 20 to 36 GHz. “ViaSat” is the satellite wireless service provider which uses “ViaSat-1” satellite to power Ka-Band. It promises to speed up to 70 Mbit/s to all aircraft and is the fastest Wi-Fi service available to the airliners.
Some aircraft use a hybrid receiver, which could switch between Ka-Band and Ku-Band depending upon the best signal strength available. This system is very useful for having a stable internet connection which could even be used to stream movies from Netflix.

Reasons for the ridiculous price for these services:

But these services are provided at a ridiculous price. There are many reasons for the high prices of a flight with onboard Wi-Fi. There is a bulky antenna which is fitted on the top of an aircraft, which functions in a manner similar to that of a TV satellite dish with an additional feature to move and adjust itself with the nearest satellite. It is very expensive to install and maintain this bulky antenna and it also increases the fuel consumption as it results in extra weight and causes hindrance in aerodynamic characteristics.   

Thanks for reading!

Suggested article: How is the aircraft thrust boosted?

Powered by Blogger.