July 2010
Intermediate to advanced
350 pages
14h 19m
English
Content preview from Smart Phone and Next Generation Mobile Computing
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140 Smart Phone and Next-Generation Mobile Computing
3.7.1 UMTS/WCDMA Versus cdma2000
A UMTS system works in two modes; its frequency-division duplex
(FDD) mode is the well-known wideband CDMA (WCDMA), whereas
its time-division duplex (TDD) mode seems to remain unnoticed
by the public. cdam2000 is the evolution of cdmaOne, the cur-
rent CDMA system in the United States. In fact, strictly speaking,
WCDMA only refers to the radio interface aspect of the entire UMTS
system. The same radio interface technology is used by NTT DoCoMo
and J-Phone (a subsidiary of Vodafone) as well. As an FDD system,
WCDMA does not require time synchronization among base stations.
It allows a bit rate up to 384 Kbps, compared with the maximum rate
of 2 Mbps in TDD UMTS system. ...