standards specify how the airwaves must be used for transmitting information. 3G was launched in Japan in 2001. As recently as mid-2010,the networks for most wireless carriers in the U.S.were 3G.3G networks were a significant improvement over 2G networks,offering higher speeds for data transfer. The improvement that 4G offers over 3G is often less pronounced. Analysts use the analogy of standard vs Hi-def TV to describe the difference between 3G and 4G