Third Generation Mobile System. Most commonly 3G networks are discussed as graceful enhancements of the GSM cellular standards. Thereby, existing GSM networks can be upgraded on a non-disruptive basis. The enhancements include greater bandwidth, more sophisticated compression techniques, and the inclusion of in-building systems. 3G networks will transmit data at 144 kilobits per second, or up to 2 megabits per second from fixed locations. This planned evolution of GSM is an integral part of the ITU-T’s vision of IMT-2000 (International Mobile Telecommunications for the year 2000), which clearly missed the target date of 2000. The aim of IMT-2000 is to harmonize worldwide 3G systems to provide global roaming.
3G has standardized (or will) three mutually incompatible standards: FDD, TDD, and CDMA2000. FDD and TDD are extensions of GSM architecture using CDMA technology in the air interface. CDMA2000 is the extension of IS95 air interface for wideband data applications. The three standards will compete with each other in the marketplace. In addition to the technical differences between the standards, there is a strong political background in the competition. FDD and TDD were proposed by European firms, and will be promoted worldwide as the heirs to GSM systems. CDMA2000 was the standard championed by Qualcomm, the USA based company with many patents in CDMA technology.
We will go into more detail on 3G in the upcoming WotD posts. Enjoy the holiday!
Subscribe to:
Post Comments (Atom)
Posts
No comments:
Post a Comment