IMT-2000 is a standard for 3G mobile networks and is defined by ITU(International Telecommunication Union).This standard includes technologies like GSM EDGE,UMTS, DECT,CDMA2000 and WIMAX.3G able to providing up to 14.4Mbps downloading and 5.76Mbps uploading speed. We can say 3G is a wireless broadband.3G has some drawbacks like 3G is not backward compatible to GSM. So 3G mobiles are not able to communicate with GSM towers until upgraded for 3G network requirement. 3G is available worldwide. I have presented here a statistical picture which I have taken from GSA website. This picture shows growth of 3G worldwide.
By using just 2G mobile technologies we are not able to send or receive data at a very high speed. Many mobile users using WAP to access internet but we are not able to watch TV or receive video calls. Upgrading to 3G is really very expensive for Telecom companies but in future customer will demand high data rates for browsing internet and watching TV live.