third generation of mobile cellular systems are intended to unify the diverse
systems we see today into a seamless radio infrastructure capable of offering
a wide range of services in different radio environments, with the quality we
have come to expect from wire line communication networks. Since the mid-80's,
studies on 3G systems have been carried out within the International Telecommunication
Union (ITU), where it was called Future Public Land Mobile Telecommunication Systems
(FPLMTS), lately renamed International Mobile Telecommunicatons-2000 (IMT-2000).In
Europe research and development on 3G technology, is commonly referred to as the
Universal Mobile Telecommunication System (UMTS) and Mobile Broadband System (MBS),
have been conducted under the European Community Research into Advanced Communications
in Europe (RACE) and Advanced Communication Technologies and Services (ACTS) programs.
With support from activities in Europe, the United States, Japan and developing
countries, World Administrative Radio Conference (WARC) of ITU identified global
bands 1885-2025Mhz and 2110-2200Mhz for IMT-2000 including 1980-2010Mhz and 2170-2200Mhz
for the mobile satellite component. Key elements in the definition of 3G systems
are the radio access system and Radio Transmission Technology (RTT). As a part
of the standardization activities, a formal request by the ITU-Radio communication
standardization sector (ITU-R) for submission of candidate RTTs for IMT-2000 has
been distributed by the ITU.
In response to this 10 proposals were submitted.
Most of the proposals use CDMA or WCDMA as their multiple access technique. So
in this seminar we are presenting the common features of WCDMA based 3G standards.The
primary focus of third generation architectures will be to attempt to seamlessly
evolve second generation systems to provide high speed data services to support
multimedia applications such as web browsing. The key word is "evolve"
-as the challenge to wireless equipment manufacturers is to provide existing customers,
namely, service providers, with a migration path that simultaneously satisfies
the requirements set forth by the International Telecommunications Union (ITU)
for 3G wireless services while preserving customer investment in existing wireless.