CDMA2000
CDMA2000 , also IS-2000 , designates a third generation (3G) cellular standard that is primarily used in America and parts of Asia and Africa for operating cellular networks . CDMA2000 used for data transmission , as well as the 3G mobile standard used in Europe Universal Mobile Telecommunications System (UMTS) is a code division multiple access (Engl. Code Division Multiple Access , CDMA) to which the title of the Standard derived. CDMA2000 is specified within the framework of IMT-2000 ( International Mobile Telecommunications-2000 ) of the ITU-R and the designation CDMA2000 is a registered trademark of the Telecommunications Industry Association (TIA-USA) in the USA.
Colloquially, the CDMA2000 mobile radio standard is incorrectly equated with the CDMA code division multiplex method . In fact, CDMA2000 is partly based on CDMA, but does not represent the CDMA multiplex method. The UMTS standard is also based on a code division multiplex method, but is not compatible with the CDMA2000 standard.
The development history of CDMA2000 goes back to the older, second generation cellular standard IS-95 (cdmaOne), which was developed by the American company Qualcomm . The processes used in CDMA2000 are partially patented and the manufacturers of base stations and mobile radio devices are registered members of the CDMA Development Group . The further development of CDMA2000 is being advanced within the framework of 3GPP2 ( 3rd Generation Partnership Project 2 ), while the UMTS mobile radio standard is being carried out within the framework of 3GPP ( 3rd Generation Partnership Project ).
Types
The CDMA2000 standard is divided into several sub-standards, which describe various details and have partly resulted from historical development. The main areas are:
- CDMA2000 1xRTT , the oldest standard for the radio interface. CDMA2000 1xRTT is sometimes also assigned to the 2.5G cell phone generation, i.e. between the two cell phone generations of the second and third generation. 1xRTT uses a bandwidth of 1.25 MHz. Data transmissions, if they are offered in addition to voice telephony, are typically limited to 144 kBit / s.
- CDMA2000 3xRTT is also known as EV-DO rev B and uses three times the bandwidth of 3.75 MHz. In addition to the larger bandwidth, the multiplex method on the radio channel has been improved and possible data rates in the downlink can be up to 4.9 Mbit / s.
- CDMA2000 EV-DO , for Evolution-Data Optimized or Evolution-Data only , refers to the CDMA2000 process for exclusive data transmission, e.g. for mobile Internet access. In addition to code division multiplexing (CDMA), time division multiplexing (TDMA) is also used in EV-DO . CDMA2000 EV-DO is particularly interesting for those providers who do not have their own infrastructure for voice telephony , such as Internet service providers . EV-DO is functionally similar to the High Speed Downlink Packet Access (HSDPA) used in UMTS .
- CDMA2000 EV-DV , for Evolution-Data / Voice , allows both the transmission of data and voice (voice telephony).
Data rates of up to 3 Mbit / s in the downlink and up to 1.8 Mbit / s in the uplink can be achieved with both EV-DV and EV-DO .
Frequency ranges
The following frequency ranges are provided for the operation of CDMA2000 mobile radio networks , whereby the sizes of the radio cells that can be achieved at the frequencies are also specified.
| Frequency (MHz) | Cell size (km) | Area (km²) | Relative number of cells |
|---|---|---|---|
| 450 | 48.9 | 7521 | 1.0 |
| 950 | 26.9 | 2269 | 3.3 |
| 1800 | 14.0 | 618 | 12.2 |
| 2100 | 12.0 | 449 | 16.2 |
CDMA2000 in Germany
Since mobile communications in Europe developed from the GSM standard, CDMA2000 and EV-DO do not play a significant role in Germany. The frequency of 1800 MHz used by CDMA2000 collides with GSM and LTE radio in Germany . The frequency range around 450 MHz has become free since the old C network was shut down at the end of 2000.
NetCologne implements the “Internet OnAir” or “Mobile SpeedNet” service on the basis of CDMA2000 and EV-DO at 450 MHz.
