1700MHz is only relevant for 3G on US T-Mobile. The i-version should be OK if you are traveling to Europe, where it seems they have standardized on frequencies and communication protocols. Wikipedia will tell you in more detail: hxxp://en.wikipedia.org/wiki/UMTS_frequency_bands
Originally Posted by esquire415
The Ray works on UK's T-Mobile (and i'm sure in other countries) and they have the i version. I looked at the specs that's being sold on Amazon and it does not say 1700Mhz so I came to a conclusion that it's pointless to get it if I can't use 3G on it. So now i'm shopping around for 2nd best
(the Arc is too big for me).
FWIW, a friend is using an unlocked AT&T iPhone on T-Mobile (US) and gets 2G reliably and almost everywhere he goes. He doesn't stream video, just data for email, web, and maps, and finds it just fine for his needs.