EV-DO - definition
A 3G technology add-on for CDMA networks that allows for theoretical download speeds as fast as 2.4 Mbps, though actual rates tend to be far slower.
There are two major versions: Release 0 and Revision A.
Release 0, the original release, is widely deployed. It offers data rates of 2.4 Mbps, with real-life speeds averaging 300-600 Kbps.
Revision A is capable of slightly faster downlink speeds of 3.1Mbps and significantly faster uplink speeds of 1.8Mbps. Rev. A also introduces enhancements that allow features such as VoIP and video calling. Although EV-DO does not support voice calls natively a future upgrade may enable VoIP.