Network Compatibility for Rogers
Rogers 3G/3.5G runs on 850/1900
No matter what people tell you about phone compatibility, you need both bands to be sure you will get full coverage. Full details on the GSMA website.
If you poke around you’ll see that Rogers also owns some 1700 spectrum. It is not in use at this point in time.
Also, the GSMA seems to think that Fido operates their 3G on 2100 but I am under the impression that this is not the case - they use 850/1900 just like Rogers.
The Punchline
If someone is trying to sell you an unlocked phone and you want to use it in Canada it needs to have the 850 and 1900 bands.