UMTS
The difference is on the standardization, on the details of modulation scheme, channel coding, etc used in the standard. UMTS is european iniatiated standard for third generation mobile system, it uses w-cdma system. The name bears wide attribute because the bandwidth is wider than the previous generation of cdma used in USA.
CDMA2000 is the american initiated standard for third generation mobile system. Some parameters are the same as UMTS (WCDMA).
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