OVERSEAS, CELLPHONES MOSTLY 'UNLOCKED'

By Leslie Cauley, USA TODAY

Are you unlocked?

If you live in the USA, probably not. Wireless devices here are generally "locked" by carriers so that they work only with that carrier's network and software applications.

In Europe, the situation is just the opposite: Phones are typically "unlocked," enabling wireless customers to switch carriers and applications with ease.

Unlocked phones, by definition, are based on GSM technology. Why? Only GSM devices use SIM cards tiny chips that relay user identification information to carriers.

Devices based on CDMA technology, the other major standard in the USA, don't have SIM cards. Instead, customer information is imbedded directly into the ...
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