"EV-DO Rev A is a 3G CDMA technology that is an upgrade of traditional EV-DO. Rev A is capable of slightly faster downlink speeds than is EV-DO Rev 0, at 3.1Mbps, as well as significantly faster uplink speeds of 1.8Mbps."
In a sense, blackberry uses EDGE therefore it doesn't assimilate with the 3G network.
Correct me if I'm wrong.