WCDMA

WCDMA or Wideband Code Division Multiple Access refers to the radio access scheme used for 3G or 3^rd generation mobile systems scattered across the earth. The WCDMA supports services like speedy internet access, transmission of videos and high resolution images with a quality that matching that of fixed networks.

The combination of CDMA air interface and GSM based networks results to the WCDMA systems. The goal of the 3^rd Generation Partnership Project or 3GPP is to guarantee the interoperability among different 3G networks. This goal has bred to the development of the WCDMA standard.

There are 2 modes of operation in WCDMA. One is the TDD duplex method. In TDD, the same frequency bands carry uplink and downlink transmissions with the use of synchronized time intervals. This divides the time slots of a physical channel into two parts: the transmission and reception.

Another mode of operation is the FDD duplex method. In this mode, two different frequency bands carry uplink and downlink transmissions. A connection is assigned a pair of frequency bands with defined separations.

With the many different frequency allocation schemes in many different regions, it is best to experience the capability of operating under the TDD of FDD modes. The result is efficient use of available connection band.

WCDMA supports transmission of data boasting a speed of 2 Mbps on local coverage and 384 Kbps on wide area coverage. The service is highly flexible as numerous parallel variable rate services are supported on every individual connection.

Capacity and coverage enhancing technologies that are to be released in the future will be easily supported by WCDMA. Examples of these technologies include adaptive antennas and superior receiver structures.

Inter-frequency hand over is also supported by WCDMA. It allows communication among different systems and includes frequency hand over to GSM.

WCDMA offers efficient packet access.