CDMA2000: A 3G mobile technology

CDMA2000 is a code-division multiple access (CDMA) version of the IMT-2000 standard developed by the International Telecommunication Union (ITU). The CDMA2000 standard is a 3G mobile technology.

The CDMA2000 family of standards includes 1xRTT, EV-DO Rev 0, EV-DO Rev A and EV-DO Rev B (now called Ultra Mobile Broadband -- UMB). The CDMA2000 family of standards is deployed by Verizon Wireless and Sprint in the U.S. and uses CDMA technology as the underlying multiplexing scheme. CDMA2000 is often confused with CDMA technology itself.

More on 3G and 4G technologies This 3G overview describes the many benefits of 3G wireless technologies.   This tutorial explains WiMAX technology, applications and terminology. It also provides an overview of WiMAX services, performance, security and devices.   Have a problem with in-building cellular coverage? Learn how a femtocell solution could help.

CDMA2000 has several advantages:

Stronger signal: CDMA2000 has the ability to use signals that arrive in the receivers with different time delays -- known as multipath. It uses the multipath signals and combines them to make the cellular signal stronger.

Drop-offs and breakups: Drop-offs occur only when the mobile device is two times further from the cellular base station. CDMA networks use a scheme called soft handoff, which minimizes signal breakup as a handset passes from one cell to another.

Analog capabilities: In rural areas of the U.S., CDMA2000 offers analog capabilities that GSM does not.

Capacity: CDMA2000 has a very high spectral capacity, so it can accommodate more users per MHz of bandwidth.

Noise reduction: CDMA2000 uses an exclusive technology called vocoder EVRC which reduces background noise.

CDMA2000 has a few disadvantages:

Channel pollution: One major problem with CDMA2000 is channel pollution, where there are too many signals from cell sites in the subscriber's phone, but none is dominant -- degrading call quality.

International roaming: Another disadvantage of this technology is the lack of international roaming capabilities and the only CDMA2000 devices that can be used internationally must also have a GSM radio. If you have mobile users who travel overseas you may want to consider a dual-mode mobile device, because it offers the most flexible solution for international mobile users.

Remote activation: CDMA2000 devices are activated remotely, by the carrier, using the phone's electronic serial number (ESN). Since each carrier has a database of all the ESNs that are approved for its network, this lets most CDMA carriers refuse to activate phones not originally intended for their network.

In the U.S., CDMA2000 and GSM are currently the competing cellular phone standards. They are about equal in the U.S. in terms of users; but, internationally, 85% of the mobile users employ GSM. The future battle in cellular communications will be between WiMAX and Long Term Evolution (a GSM technology).

It is important for mobile managers to realize that -- in the long term -- the CDMA2000 family will be phased out. Verizon is abandoning CDMA2000 and moving to the GSM family for its 4G LTE network, and Sprint is using WiMAX for its 4G rollout.

Mobile managers need to consider such factors as coverage, performance, international roaming, mobile device selection and price when planning or modifying their mobile strategy. This is a major consideration for enterprises with distributed offices, employees and international business travelers when planning their mobile communications strategy.