3G systems promise unparalleled  service in ways that have never been possible before.Multi-megabit internet access, communications using voice over internet protocol (VoIP), voice activated calls, unparalleled network capacity, and ubiquitous “always-on” access are just some of the advantages being touted by 3G developers. Companies developing 3G equipment envisions users having the ability to receive live music, conduct interactive web sessions, and have simultaneous voice and data access with multiple parties at the same time using a single mobile handset, whether driving, walking, or standing still in an office setting.

The eventual 3G evolution for CDMA systems leads to cdma2000. Several variants of cdma2000 have been developed, but they all are based on the fundamental of IS-95 and IS-95B technologies. The eventual 3G for GSM, IS-136, and PDC systems leads to wideband CDMA (W-CDMA), also called Universal Mobile Telecommunications Service (UMTS). W-CDMA is based on the network fundamental of GSM, as well as the merged versions of GSM and IS-136 through EDGE. It is fair to say that these two major 3G technologies camps, cdma2000 and W-cdma, will remain popular. Countries around the world have determined new radio spectrum bands to accommodate the 3g networks that have been deployed. In the US, additional spectrum in the upper UHF television bands near 700 MHz is also being considered for 3G.

3G W-CDMA (UMTS)   

The Universal Mobile Telecommunication system is visionary interface standard that has evolved since late 1996 under the auspicies of European Telecommunication Standards Institute (ETSI). European carriers, manufacturers, and government’s regulators collectively developed the early versions of the UMTS as a competitive open air interface standard for third generation wireless telecommunications.

UMTS or W-CDMA assures backward compatibility with the second generation GSM, IS-136 and PDC TDMA technologies, as well as all 2.5G TDMA technologies. The network structure and bit level packaging of GSM data is retained by W-CDMA, with additional capacity and bandwidth provided by new air interface. The 3G air interface standard has been designed for “always-on” packet based wireless service, so that computers, entertainment devices, and telephone may all share the same wireless network and can be connected to the internet, anytime, anywhere. W-CDMA support packet data rate up to 2.048 Mbps per user, thereby allowing high quality data, multimedia, streaming audio, streaming video and broadcast type services to consumers. Future versions of W-CDMA can support user data rate up to 8Mbps.

3G CDMA2000

The cdma2000 vision provides a seamless and evolutionary high data rate upgrade path for current users of 2G and 2.5G CDMA technology, using a building block approach that centers on the original 2G CDMA channel bandwidth of 1.2 MHz per radio channel. Based upon the original IS-95 and IS-95A (cdmaOne) CDMA standards, as well as the 2.5G IS-95B air interface. The cdmaa2000 3G standard allows wireless carriers to introduce a family of new high data rate Internet access capabilities in a gradual manner within existing systems, while assuring that such upgrades maintain backward compatibility with existing cdmaone and IS-95B subscriber equipment.                                                                                                                                                                                                             

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