W-CDMA

Wideband CDMA (W-CDMA) is the system favored by most operators able to obtain new spectrum. It has been designed to allow handovers to GSM, but is otherwise unlike it. GSM networks cannot be upgraded to W-CDMA, though some components, such as the GPRS backbone, can be reused.

The wideband designation refers to the channel bandwdith of 5 MHz. This is four times that of cdmaOne, and 25 times that of GSM. A wider bandwidth was chosen to allow higher data rates, though only in uncrowded areas with very clear reception. Unlike cdmaOne, which automatically sends every bit of information 64 times, W-CDMA adjusts the gain depending on the signal strength. Every bit is sent between 4 and 128 times, which means that greater bandwidth is available ...

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