CDMA2000, also known as CDMA20001xRTT, 1X or IS-2000, is a 3G mobile telecommunications standard for wireless transmission with significant deployments worldwide. It is used primarily to deliver circuit switched services such as voice, SMS and MMS, though CDMA2000 Release 0 is also capable of peak data rates of 153.6 kbit/s in both forward and reverse links.
CDMA2000 is based on code division multiplex access (CDMA), where all users share the same 1.25 MHz-wide channel, but use individual pseudo noise (PN) sequences for differentiation. CDMA2000 is fully downward compatible with CdmaOne (IS-95), making the upgrade path easy and seamless for operators.
The voice-centric CDMA2000 1X is evolving to 1X Advanced, which quadruples (4x!) the capacity of today’s 1X networks. This unprecedented capacity increase offered by 1X Advanced can also be used to free up spectrum for high revenue-earning data services or to achieve up to 70 percent increase in coverage. In the long term, the wireless industry is moving toward richer packet-based voice (VoIP) such as VoLTE (voice over LTE), VoIP over HSPA+ and EV-DO.
1xEV-DO, also known as EV-DO, is an all-IP 3G mobile telecommunications standard for wireless transmission of data with worldwide deployments. The technology has gone through several revisions from Release 0 to Revision A, Revision B, and DO-Advanced.
Revision A introduced enhanced capabilities such as reduced latency, QoS support and increased the peak data rate to 3.1 Mbit/s in the forward link and 1.8 Mbit/s in the reverse link. This provided support for a variety of delay-sensitive applications such as VoIP and push-to-talk services.
Revision B additionally offers multicarrier capabilities and provides higher single-carrier data rates. The data rates are up to 4.9 Mbit/s in the DL and 1.8 Mbit/s in the UL and may be obtained for each of the carriers. According to the standard, up to 15 carriers may be aggregated for transmission.
All revisions are completely downward compatible and are based on a channel bandwidth of 1.25 MHz operating on the same frequency bands, making EV-DO technology and test solutions requirements similar to CDMA2000 1xRTT.
These two technologies may be operated in a hybrid mode. This way it is possible for a mobile station to take advantage of the better suited feature of each technology depending on the application.
CDMA2000 and 1xEV-DO are specified in 3GPP2 (3rd Generation Partnership Project 2).