The European Commision has opened the door for mobile phones on planes, introducing measures to harmonize the technical and licensing requirements for mobiles services in the sky.

This means that 90 percent of European air passengers can remain contactable during flights, according to the Commission. The commercial systems currently envisaged for airlines are focussing on MCA services for GSM (Global System for Mobile Communications) phones operating in the 1800MHz frequency bands, which over 90 percent of air passengers are estimated to carry when travelling.

As a result of the introduction of the measures by the Commission, local regulators will be able to hand out licenses to make services a reality.

One regulatory decision for all of Europe was required for this new service to come into being, according to Viviane Reding, the European Union Telecommunications Commissioner.

"In-flight mobile phone services can be a very interesting new service especially for those business travellers who need to be ready to communicate wherever they are," she said in a statement.

At the same time, if users get "shock phone bills, the service will not take off," Reding warned.

The ability to make phone calls on board planes is moving forward on severel fronts.

Recently the world's first authorized in-flight mobile phone calls on a commercial flight, by Emirates Airline, took place last month following the introduction of the AeroMobile system, a joint venture between Telenor and ARINC, by Emirates Airline.

Field studies and market research clearly show that there is strong interest in in-flight mobile communications among passengers, particularly among business travellers and frequent flyers, but also by leisure travellers, according to Telenor.

But not everyone is convinced.

Airlines have to take into considiration the fact that many passengers don't want mobile coverage on airplanes, according to Monica Hultberg, spokeswoman at Scandinavian Airlines.

"A couple of years ago we did a survey, and 50 percent didn't like the idea," said Hultberg, adding that it's monitoring how the area develops.