07-18-2009, 09:14 AM
Join Date: Aug 2004
Location: Somewhere in the swamps of Jersey
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The 8830 World Edition has support for two radio frequencies. It uses CDMA (for Verizon) in North America. It also supports 900 and 1800 MHz GSM. Those are frequencies used everywhere outside of North America.
The 8830 has a "SIM Card" - Subscriber Identity Module - that controls how the GSM features work.
"Unlocking" means that you can use the phone (GSM piece) on a carrier other than the one the phone came with. For example, if you have the 8830 unlocked, you could go to the UK, get a local SIM card (with a local UK number) and use it. However, you would not have full BlackBerry services, including e-mail, with the local SIM.
People generally unlock phones to use a phone that is not sold by their carrier (use a Bold 9000 on T-Mobile), or to use a less expensive service in another country.