The European Union has cleared the way for airlines to allow cell phone calls during flights in European skies. Some questions and answers:

Q. How does the technology work?

A. Users of cell phones and other wireless devices using the European GSM technology with roaming capability will be able to make and receive calls, routed through a base station on the plane. The onboard network uses small masts that force all mobile phones to connect to its network, avoiding interference with the plane’s navigation system. The onboard network covers the entire plane and sends calls through a satellite to networks on the ground. The same satellite link is already used by the captain and flight crew for communications.

Q. How much will it cost to make an onboard call?

A. Users will be charged by their existing phone companies according to rates set by providers, airlines and network operators. European officials have warned consumers to expect higher fees because of the cost of setting up the onboard networks.

Q. What about safety?

A. European regulators and the airline industry say new technology developed and tested in recent years has made it safe for passengers to use cell phones during flight, but only when the plane climbs above 10,000 feet. That’s when other electronic devices, such as portable music players and laptops, are allowed. They say the new onboard cell network does not interfere with communication or navigation systems. Cell phones will not be allowed during takeoff or landing and can be shut off by the captain during turbulence or any other time. There are no plans to lift the ban on U.S. carriers.

Q. What about flights leaving or coming to Europe?

A. It is not yet clear whether airlines will turn off the service once they leave European airspace. When a flight originating in Europe enters international airspace, it’s governed by the rules of the country where the airline is registered. Cell phone service could be shut down before a plane enters the airspace of another country, such as the United States.

Q. What about a code of conduct on the use of cell phones onboard?

A. The European Union is recommending that airlines draft etiquette guidelines to control or limit the use of cell phones during flights to avoid in-flight flare-ups between closely confined passengers. For example, airlines could recommend passengers switch their phones to silent mode or limit services to the quieter options of text-messaging or e-mail. Airlines could also ban calls during night flights.