network (internationally speaking)? I know that in order to work with 3G data, phones need to access to certain wireless bands, so, my question is, if, regardless of were an iPhone 4 was bought (unlocked, through the Apple store) the phone can actually access all of the bands in which 3G service is transmitted (because yes, in the details page it states like 4 o 5 different bands, but I don't know if it is/has to be limited to a specific band).

For example, SonyEricsson makes different handsets for different parts of the world, and marks them as "a", "i" in the end (i.e. c905a, c905i), stating that it's an "american" or "international" version, and that has to do with the wireless bands that the handset can access, and I'm not sure if it is the same thing with the iPhone.

Thanks!