Universal Mobile Telecommunications Service (UMTS)

When the International Telecommunications Union solicited solutions to
meet the requirements laid down for IMT-2000, a number of technologies
were proposed by various standards groups. These included both Time Division
Multiple Access (TDMA) solutions and Code Division Multiple Access
(CDMA) solutions. They also included both Frequency Division Duplex
(FDD) and Time Division Duplex (TDD) solutions.
The European Telecommunications Standards Institute (ETSI) agreed on
a WCDMA solution using FDD. In Japan, a WCDMA solution was also proposed,
with both TDD and FDD options. In Korea, two different types of
CDMA solution were proposed—one similar to the European and Japanese
proposals, and one similar to a CDMA proposal being considered in North
America (CDMA2000, which is an evolution of IS-95 CDMA).
It was clear that a number of groups were working on very similar technologies
and it was fairly obvious that the most effective way forward was
to pool resources. This led to the creation of two groups—the Third Generation
Partnership Project (3GPP) and 3GPP2. 3GPP works on UMTS, which
is based on WCDMA, and 3GPP2 works on CDMA2000. The following discussion
provides a brief of UMTS.