Americans are at a disadvantage when it comes to cell phones overseas, because most of the world uses a GSM (Global System for Mobile Communications) standard, Schukai said.

CNN: Navigating cell phone headaches overseas

The GSM (Global System for Mobile Communications) standard is used throughout Europe, making it a much less fragmented market for mobile communications than the U.S., and mobile phone penetration is particularly high in Northern Europe.

CNN: Handheld use to soar in Europe

At the time cellular calls flitted from tower to tower under an electronic protocol later known as GSM (global system for mobile), a group effort whose three progenitors--Nokia, Ericsson and Motorola--had pooled their patents and didn't charge one another any royalties.

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