sophist, just to expand a little
UMTS is the European version of 3G which includes WCDMA FDD and TDD. Japan and others are also focusing on UMTS.
The competing 3G standard is cdma2000, the Qualcomm version.
Although InterDig claims to have essential IPR in all 3G standards, their focus is on UMTS. InterDig is codeveloping an FDD chip w/Infineon and is an acknowledged leader in WCDMA TDD (WTDD) technology development.
I don't think TD-SCDMA is oficially part of UMTS; however, the recent press release by Siemens/NEC seems to include TD-SCDMA along with FDD and TDD as a world standard.
Bottom line: GO UMTS!