Compatibility help needed

[Jan1ce]

I want to buy an unlocked phone but it is asking me for COMPATIBILITY:

T-Mobile

Asian & European Carriers

Unionn Wireless

NEP wireless

Longline wireless

iWireless

Indigo wireless

Farmers wireless

Unicell

Edge wireless

Cincinnati bell wireless

Quantum Wireless

SunCom Wireless Holdings Inc

Wireless Alliance

I have no idea which one to submit to the vendor. Anyone have a clue? I've never come across this. To me, an unlocked phone is an unlocked phone and I've used them for years with my FIDO SIM card. The phone is a Sony Ericsson W380i so also OK with Fido. Can anyone help me know which one to choose? Help!

***Edited to add labels***

[JustinCredible · Accepted solution]

An unlocked phone only works with carriers that use the same frequency as the phone you purchase. For example, an unlocked Fido phone will not work on Wind Mobile. You need a phone designed for AT&T/Rogers/Bellus frequencies of 850/1900 MHz. Generally known as North American phones, but there are other frequencies here too now. Wind, Mobilicity and T-Mobile use 1700/2100 MHz 3G and Modrek on the way. Each phone has different frequencies so make sure you look it up! Go to www.gsmarena.com to research phone models for compatibility.