Have you ever wondered how to get inflight Wi-Fi signals at 35000 feet above the ground?

Once you are onboard an airplane, airline staff often remind you to keep your mobile devices in flight mode. This is to avoid interference of the mobile signals with communication equipment of the airplane.

In the past, there was no connectivity to mobile towers few hundred feet above the ground (after takeoff). Travelers have to wait until the aircraft lands at the airport to use their Smartphone.

This is an old story, technology has been changed a lot since then.

What is inflight Wi-Fi system?

With the introduction of inflight Wi-Fi systems in commercial aviation during the end of 2000s, passengers can keep their mobile devices or personal computers connected to the Wi-Fi network onboard.

Modern airplanes are equipped with inflight internet connectivity which ensures uninterrupted data during the flight.

How does inflight Wi-Fi system works?

Similar to our mobile network, Inflight Wi-Fi connectivity requires a base station to send and receive signals. It works in two modes; Ground based connectivity and Satellite based connectivity.

Air to Ground (ATG) Ground based connectivity

Ground based connectivity also known as Air to Ground connectivity works exactly like our conventional mobile network. It has a base station on the ground with antenna arrays facing upwards to maintain signal connectivity to moving airplanes.

Network of base stations are required to cover a large geographical area. Transceiver antenna module will be installed on the belly of an airplane.

Gogo, one of the infligt internet providers will use their 5G network with 250 base station towers around United States.  According to Gogo, they will be able to provide network speed up to ten times higher than current systems using their 5G network.

Advantages of Air to Ground connectivity

• Latency is lower since the airplane is only 3500 feet above ground (average approximation)
• Less complex compared to satellite based system
• Operators can make use of existing network for this task
• Cost effective solution and infrastructure
• Easy to maintain the system

Disadvantages of Air to Ground connectivity

• Requires large number of base station towers to maintain connectivity to cover large geographical area
• Signal quality affected by atmospheric changes (heavy rain, fog etc…)
• Not feasible option in mountainous areas, oceans and deserts
• Switching from one base station to another could cause interruptions and delay in connectivity  
• Network load will affect the quality of service

Satellite based connectivity

Satellite based connectivity uses a network of satellites dedicated to provide data connectivity to moving airplanes. Transceiver antenna module will be installed on top of airplane.

Advantages of Satellite based connectivity

• Each satellite can server more number of aircrafts at same time
• Fast network using higher bandwidth signals compared to ground based system
• More immune to atmospheric changes

Disadvantages of Satellite based system

• High latency signals due to the distance from the airplane to satellite is longer than distance from airplane to ground
• Higher cost for implementation and maintenance
• Often need spectrum license to operate
• Complexity is high (not all operators own satellites)  
• Requires expensive transceiver units on airplane and often airplanes need to be grounded for many days (for installation and maintenance).

Future of inflight internet connectivity

Internet connectivity has become an inevitable factor in our daily life. We will be able to continue to chat with our friends during flight and share some photo of meals onboard.

Inflight internet connectivity of commercial aviation is expected to grow exponentially in coming years. Business passengers can rely on the inflight internet connectivity to continue with their projects even during flights.  

Gogo, one of the service providers in this sector has recently announced that they are introducing Air to ground 5G network for smaller jets.  Once the full capability of the 5G networks are available, inflight Wi-Fi and entertainment systems will help passengers keep connected to faster internet and watch their favorite shows during flight.