CDMA2000 is a technology for the development of cdmaOne/IS-95 to 3rd generation services. Also known as IMT-CDMA Multi-Carrier or IS-2000 is the main route for CDMA operators to second-and-a-half ( 2.5G) and third generation (3G) cellular networks. A set of new standards that define the new air interface and the Radio Access and Core Network changes that will enhance network capacity, improve speed and bandwidth to mobile terminals, and allow end-to-end IP services has been created by the standard-setting body behind CDMA2000 known as 3GPP2. CDMA2000 will provide improved services to cdmaOne subscribers, as well as forward and backward capabilities in terminals.

Deployed in various phases, the first phase called CDMA2000 1x, supports an average of 144 kbps packet data in a mobile environment. The second release 1x-EV-DO will support data rates up to 2 Mbits/sec on a dedicated data carrier. Lastly, 1x-EV-DV will supports higher peak rates and simultaneous voice and high-speed data, as well as improved Quality of Service mechanisms. The CDMA2000 PCN(Packet Core Network) is one of the first steps in the evolution of CDMA2000 systems to All-IP and multi-media architecture that allows for the delivery of packet data services with more speed and security.

CDMA2000 is a hybrid 2.5G / 3G technology of mobile telecommunications standards that use CDMA, a multiple access scheme for digital radio, to send voice, data, and signalling data (such as a dialed telephone number) between mobile phones and cell sites. CDMA2000 is considered a 2.5G technology in 1xRTT and a 3G technology in EVDO.

CDMA (code division multiple access) is a mobile digital radio technology where channels are defined with codes (PN sequences). CDMA permits many simultaneous transmitters on the same frequency channel, unlike TDMA (time division multiple access), used in GSM and D-AMPS, and FDMA, used in AMPS ("analog" cellular). Since more phones can be served by fewer cell sites, CDMA-based standards have a significant economic advantage over TDMA- or FDMA-based standards.

CDMA2000 has a relatively long technical history, and remains compatible with the older CDMA telephony methods (such as cdmaOne) first developed by Qualcomm, a commercial company, and holder of several key international patents on the technology.

The CDMA2000 standards CDMA2000 1xRTT, CDMA2000 EV-DO, and CDMA2000 EV-DV are approved radio interfaces for the ITU's IMT-2000 standard and a direct successor to 2G CDMA, IS-95 (cdmaOne). CDMA2000 is standardized by 3GPP2.

CDMA2000 is a registered trademark of the Telecommunications Industry Association (TIA-USA) in the United States, not a generic term like CDMA. (This is similar to how TIA has branded their 2G CDMA standard, IS-95, as cdmaOne.)

CDMA2000 is an incompatible competitor of the other major 3G standard UMTS. It is defined to operate at 450 MHz, 700 MHz, 800 MHz, 900 MHz, 1700 MHz, 1800 MHz, 1900 MHz, and 2100 MHz.

CDMA2000 1xRTT, the core CDMA2000 wireless air interface standard, is also known as 1x, 1xRTT, and IS-2000. The designation "1x", meaning "1 times Radio Transmission Technology", indicates the same RF bandwidth as IS-95: a duplex pair of 1.25 MHz radio channels. This contrasts with 3xRTT, which uses channels 3 times as wide (3.75 MHz) channels. 1xRTT almost doubles the capacity of IS-95 by adding 64 more traffic channels to the forward link, orthogonal to (in quadrature with) the original set of 64. Although capable of higher data rates, most deployments are limited to a peak of 144 kbit/s. IMT-2000 also made changes to the data link layer for the greater use of data services, including medium and link access control protocols and QoS. The IS-95 data link layer only provided "best effort delivery" for data and circuit switched channel for voice (i.e., a voice frame once every 20 ms).

1xRTT officially qualifies as 3G technology, but it is considered by some to be a 2.5G (or sometimes 2.75G) technology. This allows it to be deployed in 2G spectrum in some countries that limit 3G systems to certain bands.

CDMA2000 3x is (also known as EV-DO rev B) is a multi-carrier evolution of the Rev A specification. It maintains the capabilities of EVDO Rev A, and provides the following enhancements:

* Higher rates per carrier (up to 4.9 Mbit/s on the downlink per carrier). Typical deployments are expected to include 3 carriers for a peak rate of 14.7 Mbit/s
* Higher rates by bundling multiple channels together enhance the user experience and enables new services such as high definition video streaming.
* Uses statistical multiplexing across channels to further reduce latency, enhancing the experience for latency-sensitive services such as gaming, video telephony, remote console sessions and web browsing.
* Increased talk-time and standby time
* Hybrid frequency re-use which reduces the interference from the adjacent sectors and improves the rates that can be offered, especially to users at the edge of the cell.
* Efficient support for services that have asymmetric download and upload requirements (i.e. different data rates required in each direction) such as file transfers, web browsing, and broadband multimedia content delivery.

Cdma2000 specification was developed by the Third Generation Partnership Project 2 (3GPP2), a partnership consisting of five telecommunications standards bodies: ARIB and TTC in Japan, CWTS in China, TTA in Korea and TIA in North America. Cdma2000 has already been implemented to several networks as an evolutionary step from cdmaOne as cdma2000 provides full backward compatibility with IS-95B. Cdma2000 is not constrained to only the IMT-2000 band, but operators can also overlay acdma2000 1x system, which supports 144 kbps now and data rates up to 307 kbps in the future, on top of their existing cdmaOne network.

The evolution of cdma2000 1x is labeled cdma2000 1xEV. 1xEV will be implemented in steps: 1xEV-DO and 1xEV-DV. 1xEV-DO stands for "1x Evolution Data Only". 1xEV-DV stands for "1x Evolution Data and Voice". Both 1xEV cdma2000 evolution steps will use a standard 1.25 MHz carrier. 1xEV-DO probably will be available for cdma2000 operators during 2002 and 1xEV-DV solutions will be available approximately late 2003 or early 2004.

Key features of CDMA2000 are:

* Leading performance: CDMA2000 performance in terms of data-speeds, voice capacity and latencies continue to outperform in commercial deployments other comparable technologies
* Efficient use of spectrum: CDMA2000 technologies offer the highest voice capacity and data throughput using the least amount of spectrum, lowering the cost of delivery for operators and delivering superior customer experience for the end users
* Support for advanced mobile services: CDMA2000 1xEV-DO enables the delivery of a broad range of advanced services, such as high-performance VoIP, push-to-talk, video telephony, multimedia messaging, multicasting and multi-playing online gaming with richly rendered 3D graphics
* All-IP – CDMA2000 technologies are compatible with IP and ready to support network convergence. Today, CDMA2000 operators that have deployed IP-based services enjoy more flexibility and higher bandwidth efficiencies, which translate into greater control and significant cost savings
* Devices selection: CDMA2000 offers the broadest selection of devices and has a significant cost advantage compared to other 3G technologies to meet the diverse market needs around the world
* Seamless evolution path : CDMA2000 has a solid and long-term evolution path which is built on the principle of backward and forward compatibility, in-band migration, and support of hybrid network configurations
* Flexibility: CDMA2000 systems have been designed for urban as well as remote rural areas for fixed wireless, wireless local loop (WLL), limited mobility and full mobilility applications in multiple spectrum bands, including 450 MHz, 800 MHz, 1700 MHz, 1900Mhz and 2100 MHz

CDMA2000 Advantages

* Superior Voice Clarity
* High-Speed Broadband Data Connectivity
* Low End-to-End Latency
* Increased Voice and Data Throughput Capacity
* Time-to-Market Performance Advantage
* Long-Term, Robust and Evolutionary Migration Path with Forward and Backward Compatibility
* Differentiated Value-Added Services such as VoIP, PTT, Multicasting, Position Location, etc.
* Flexible Network Architecture with connectivity to ANSI-41, GSM-MAP and IP-based Networks and flexible Backhaul Connectivity (see the text at the end – we can do that later)
* Application, User and Flow-based Quality of Service (QoS)
* Flexible Spectrum Allocations with Excellent Propagation Characteristics
* Robust Link Budget for Extended Coverage and Increased Data Throughputs at the Cell Edge
* Multi-mode, Multi-band, Global Roaming
* Improved Security and Privacy
* Lower Total Cost of Ownership (TCO)