Can an unlocked US IPhone 3GS be used in Canada?

I've ordered an unlocked iPhone 3GS from Amazon, but i'm just worried it won't work on my network (Bell Mobility) because it says it will work on any GSM network. But from what I understand bell is a HSDPA network or somthing like that. Could anyone clear this up for me?

It should work, I had the iPhone 4 on Bell and currently have the 5

If the iPhone is a Factory Unlock phone then it should work in any carriers. You can also switch from different network without issue.