Advantage CDMA .
CDMA technology itself has various advantages when applied in mobile systems. Benefits include:
* Only need one radio is required for some sectors / cell
* Equalizer does not need to overcome the interference signal spectrum
* Be able to join with other access methods, does not require the time (guard time) to see time and guard band (guard band) to keep the intervention antarkanal
* Does not require the allocation and management of frequency
* Has the capacity to smooth the user to restrict access
* Have the protection of the tapping process.
in Fixwireless and CDMA Mobile Phone also Data Access
A number of different terms used to refer to the implementation of CDMA. Standard who first initiated by QUALCOMM was known as IS-95, IS refers to an Interim Standard of the Telecommunications Industry Association (TIA). IS-95 is often referred to as 2G or second generation cellular. CdmaOne trademarks of QUALCOMM is also used to take the 2G CDMA standard.
After several revisions, IS-95 is replaced by the standard IS-2000. This standard was introduced to meet several criteria in the existing IMT-2000 specification for 3G, or third generation mobile. This standard is also referred to as 1xRTT which simply means "1 times Radio Transmission Technology" which indicates that the IS-2000 using the channel with 1.25-MHz is used as the standard IS-95 of the original. A related scheme called 3xRTT bearer channel using three 1.25-MHz wide band to a 3.75-MHz that allows the rapid explosion of data (data burst rates) is higher for an individual user, but the scheme has not been used 3xRTT commercial. The latest, QUALCOMM has led the creation of new technology, called CDMA-based 1xEV-DO, or IS-856, which is able to provide packet data transmission rate is higher as required by IMT-2000 and desired by the wireless network operator.
QUALCOMM CDMA system includes a signal that time is very accurate (usually referring to a GPS receiver at the central station cells (cell base station)), so that the hours-based CDMA mobile phone is the type of day that the popular radio for use on the network computer. Main advantage using CDMA mobile phone signals for reference day is that they will work better in the building, so that removes the need to install a GPS antenna outside the building.
Which is also often dikacaukan with CDMA is W-CDMA. CDMA technique is used as the principle of the air interface W-CDMA, and the air interface W-CDMA is used in the global 3G standard UMTS and the Japanese 3G standard FOMA, by NTT DoCoMo and Vodafone; but anyway, the family CDMA standards (including cdmaOne and CDMA2000) are not compatible with W-CDMA standard.
Other important applications of CDMA, and precede all of the different cellular CDMA, is the Global Positioning System, GPS.
High-Speed Downlink Packet Access (HSDPA) is a protocol and mobile phone technology, sometimes referred to as 3.5 G.
First phase with a HSDPA 4.1 Mbps. Then, following a phase 2 with a capacity of 11 Mbps and maximum downlink peak data rate up to 14 Mbit / s. This technology was developed from the WCDMA the same as EV-DO CDMA2000 develop. HSDPA provides evolution path for network Universal Mobile Telecommunications System (UMTS), which allows for the use of data capacity is greater (up to 14.4 Mbit / sec down direction).
HSDPA is an evolution of W-CDMA standard and is designed to increase data transfer speeds 5x higher. HSDPA memdefinisikan a channel W-CDMA is a new, namely high-speed downlink shared channel (HS-DSCH), which is operating with a different channel W-CDMA is now. Up to now only the use of HSDPA technology in the communication under the direction of mobile phone.
EVDO, also known as EV-DO, 1xEvDO and 1xEV-DO is a standard in high-speed wireless broadband. EVDO stands for "Evolution, Data Only" or "Evolution, data optimized". Term issued by the authorized Telecommunications Industry Association is CDMA2000, is a high-speed data interface on the media air. EVDO one of two main kinds of standards to the wireless generation, or 3G-3. while the other is a standard W-CDMA.
Wideband Code-Division Multiple Access or Wideband-written regular CDMA or W-CDMA, a third generation technology (3G) to GSM, UMTS is also normal (Universal Mobile Telecommunication System). This technology is not compatible with the CDMA2000 or often also called the CDMA only.
WCDMA can reach speed of 384 kbps and in the akan datang akan may be increased up to around 10Mbps.
This technology uses Wideband-AMR (adaptive multi-rate) for the codification voice (voice codec) so that the sound quality to be better than the previous generation.