Have you noticed a slight bulge above commercial aircraft lately? This is typically used to hold a pair of antennae that pick up signals. In some aircraft, the antennas are placed in the belly of the fuselage.
Also, it may not be possible to keep all your devices on at the same time. There are other passengers who can download large data. You often get 20-50MB of free Wi-Fi on an airline like Emirates, usually in business class or premium economy. Getting a strong signal is always a challenge when flying over the ocean, as there are no towers within range.
Gogo's in-flight Wi-Fi is one of the best around, as they use a hybrid of ground and satellite signals for maximum coverage. They call their ground systems ATG (Air-to-Ground). In the stratosphere they use Kyou band (12 to 18 GHz), ideal for long distances. Of course, Kyou also works for International Space Station astronauts to communicate with ground base.
OnAir, Immarsat, and Panasonic Aviation are other major providers of aviation WiFi solutions. Immarsat is pioneering Europe's aeronautical network with the aim of delivering world-class speeds and wider coverage.
As technology improves, airlines could keep a lot of bandwidth buffer to avoid latency issues. It is expected that in six years, almost all airlines will offer high-speed Wi-Fi to their passengers. For some of us, this may not be good news. After all, we can no longer use the "I'm sorry" excuse. I couldn't check your emails because my phone was in airplane mode.
