4.Multi-Band

In order to achieve a maximum transmission speed of 2 Mbps, which is one of the objectives of the third-generation IMT-2000 mobile communications system, frequency resources must be flexibly utilized to provide the optimal transmission conditions depending on the service.

Accordingly, W-CDMA includes four basic bandwidths (1.25 MHz, 5 MHz, 10 MHz, 20 MHz) and spread bandwidths -- namely, spectrum-spread codes with different "chip rates" assigned in accordance with the transmission rate (Note).

(Note) While subsequent ARIB and ETSI studies on basic 5-MHz bandwidth radio systems also included the 10-MHz and 20-MHz bandwidths, the current standard is set at 5MHz only as 2-Mbps transmissions are fully possible even with a 5-MHz carrier. This also enabled detailed specifications to be completed at an early stage.

W-CDMA frequency bandwidths and chip rates (as of September 1999)

Created 1999/03

Updated 2002/02