All about CDMA

Glossary

* AMPS
Advance Mobile Phone System, is a somewhat ironic name for the original cellular system authorized in the US. It uses an analog FM radio link and it is very easy to eavesdrop on it. AMPS is particularly inefficient in use of spectrum compared to any of the digital standards.
* CDMA
CDMA stands for Code Division Multiple Access and refers to a technology for the radio link which utilizes spread spectrum communication with very tightly controlled power levels by all participants. There is currently (2/2000) only one commercial system which uses CDMA, covered by the specifications IS-95 and J-STD-008, and thus the term CDMA is often used to refer to that system.

* Dual Band
Dual band refers to a phone capable of operating in 2 different frequency bands, e.g. both at 800 MHZ cellular and at 1900 MHZ PCS. Not all PCS phones are dual band. When a CDMA phone is dual band, most commonly it means it supports CDMA at 1900 MHZ and AMPS at 800 MHZ. Some phones exist which do both of those and also support CDMA at 800 MHZ; these are usually referred to as tri mode.

* 1G
First Generation. Cellular systems based on analog technology. 1G Wireless systems were designed to carry only voice traffic and were limited by network capacity constraints. 1G networks were typicaly based on AMPS.
* 2G
Second Genereation. Cellular wireless based on digital technology. 2G systems offer increased voice quality and capacity to handle more calls. Historically, 2G systems provided voice and 9.6-14.4 Kbps circuit-switched data service. Today, 2G systems are being replaced by 2.5G and 3G network.
* 2.5G
2.5G refers to technology that is more advanced than 2G, but which does not meet the requirements for 3G. 2.5G technology is added to a 2G network to provide packet-data service and data rates that range from 20 to 40 Kbps. In practice, 2.5G is synonymous with the GPRS technology that has been added to GSM networks.
* 3G
Systems designed to increase voice capacity and provide high-speed data. According to the official ITU definition, a 3G network must provide a minimum of 144 Kbps from a moving location, or up to 2 Mbps from a fixed location. 3G will enable users with high-speed data, advanced global roaming and enhanced multimedia capabilities. CDMA provides the basis for 3G technology, which has been implemented as CDMA2000 and WCDMA (UMTS)

* CDMA2000
Provides a set of specifications which offer enhanced voice and data capacity. CDMA2000 is recognized by the ITU as global standard for 3G wireless systems.
* BTS
Base Transceiver Station (BTS) - the radio part of a wireless network (typically cellular or PCS) that includes the transmitters and receivers, antennas and tower that is used to communicate with mobile radios. A BTS is connected to a Base Station Controller (BCS)
* BCS
A Base Station Controller is an automatic coordinator that permits one or more base transceiver stations (BTS) in a wireless network to communicate with a mobile switching center