cdma2000, also known as cdma2000 1xRTT, 1X or IS-2000, is a 3G mobile telecommunications standard for wireless transmission of voice and data with significant deployments worldwide.
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 new cdma2000 Revision E expands voice capacity by supporting new radio configurations, and it contains enhanced features such as femtocell support, geolocation support and cell identification broadcast messaging.