Ticket prices will likely rise

A basic fact about radio communications is that if two signals use the same channel they might interfere with each other.

That's a big problem for planes because they rely almost totally on radio signals to communicate with traffic control centers on the ground, namely reporting their situation and receiving orders from the latter. A plane's navigation system also relies heavily on radio communications. If these signals are interfered with, it could result in a fatal accident.

It was when cellphones became popular in the 1990s that the civil aviation industry started to worry about their use possibly interfering with the communication signals of flights. There were even reports about the navigation system of flights suffering problems when passengers made phone calls during flights. No accident has been confirmed to have been caused by the use of a cellphone, but for safety's sake one country after another banned the use of cellphones during flights.

With the popularizing of electronic devices such as laptops, tablets, and smartphones, research results tend to show that these devices won't interfere with the communication of flights as long as they are legally manufactured. That's why one country after another has loosened the ban. A quite common practice is to allow passengers to freely use their electronic devices when the plane is cruising, but they must turn them into flight mode during the take-offs and landing, because most accidents happen during these two periods.

It should be noted that even if airlines in China allow passengers to use cellphones during flights, the cellphones will have no signal because they cannot connect to any base station stably. They will have to rely on a plane's wifi, which could carry a small base station on its back, for data transmission.

Shou Tuo, a senior editor at guokr.com, courtesy: guokr.com