Evolution to 3G and UMTS Service Overview

Evolution to 3G and UMTS Service Overview pdf

Third generation (3G) systems, such as the Universal Mobile Telecommunications
System (UMTS) or cdma 2000, are the result of evolution from voice optimised
analogue systems like the North American Advanced Mobile Phone System (AMPS),
Nordic Mobile Telephone System (NMT) or UK based Total Access Communication
System (TACS). The relatively poor spectral efficiency, security and limited roaming
of these first generation (1G) systems led to second generation (2G) systems such
as the European Global System for Mobile Communication (GSM) and digital AMPS
(D-AMPS) from North America, which also produced cdma One, a narrowband CDMA
system which demonstrated clearly the potential of code division multiple access
(CDMA) for mobile communication. GSM has become a de facto global standard and
under Phase 2+ evolution can offer packet-switched data with the General Packet
Radio Service (GPRS) up to 115.2kbps and ultimately 384kbps with GPRS + EDGE
(Enhanced Data for Global Evolution). With High Speed Circuit Switched Data
(HSCSD), circuit-switched data to 57.6kbps can be supported. The CDMA technique
has been retained for the major 3G systems, but in wideband form (W-CDMA) to
support much higher user data rates. This will permit multi-media services to operate
with high quality and make possible bandwidth on demand for mobile
communication. Both CS and PS data are supported, with user rates up to
2.048Mbps peak (likely to rise in the future). 3G systems also promise better spectral
efficiency, security and roaming.