1xEV-DO (EVDO) is a 3G standard for CDMA-based networks. As a 3G technology, it focuses on bringing high-speed data to CDMA networks.
EVDO provides data rates over 10 times faster than 1xRTT, the previous data technology for CDMA networks. EVDO is not as fast as the newer LTE 4G standard.
In terms of data speed and general technology evolution, the closest equivalent to EVDO for GSM/WCDMA networks would be HSDPA.
Part of a family of CDMA2000 1x digital wireless standards. EVDO originally stood for "EVolution, Data-Only", but later was also referred to as "EVolution, Data-Optimized".
Unlike other proposed "1x" standards, EVDO only addresses data, not voice. It requires a dedicated radio frequency range, separate from voice networks using standards such as 1xRTT.
There are currently two main versions of EVDO: "Release 0" and "Revision A".
Release 0 (r0) is the original version, and the first to be widely deployed. Rel. 0 offers data rates up to 2.4 mbps, averaging 300-600 kbps in the real world. This is much faster than the 50-80 kbps typically offered by the older 1xRTT technology.
Revision A (rA) integrates most of the faster data technology originally designed for the 1xEV-DV Revision D standard, and improves latency. These enhancements allow features such as VoIP and video calling. The downlink (download) theoretical peak data rate compared to Release 0 is improved from 2.4 mbps to 3.1 mbps.
EVDO is based on a technology initially known as "HDR" (High Data Rate) or "HRPD" (High Rate Packet Data), developed by Qualcomm. The international standard is known as IS-856.