09-05-2010, 10:53 AM
4g technology.pdf (Size: 35.83 KB / Downloads: 594)
Presented By:
BHAVNA SHARMA & VENY GUPTA
B.TECH 3RD YEAR
Introduction
The first commercial mobile networks were launched in the mid-1980s.Since then the mobile communication world had been witnessing rapid changes. First generation US universal coverage used Classic Wire line MaBel Public switched telephone network(PSTN) along with a diversified cellular architecture and use of analog signals pertaining features like speech and TAC(type allocation codes). Second generation wireless supported more users within a cell with digital technology which allowed many users to use a multiplexed channel. This was however more focused on making global roaming realistic. But this was still meant for speech and not data. 2.5G allowed the carriers to increase the data rates with a minimum software upgrade at base transceiver stations (BTS). Still the data transmission speed was low. It supported techniques like GPRS, EDGE, etc. The inadequacy in case of existing bandwidth and multimedia services pumped 3G networks in market infrastructure. This technique was based on radio interface. It offered significant user benefits including high quality wireless multimedia to a convergent network of fixed, cellular and satellite components. It involved techniques like evolution to all IP networking including VOIP, CDMA 2000/WCDMA, WiMAX , Hyper LAN, etc.