What's 3G technolige?Please answer it in English.

What's 3G technolige?Please answer it in English.

3G (wCDMA,CDMA-2000,UMTS,FOMA) in Japan FAQ
1.What are third generation (3G) wireless communications?Second generation (2G) cellular data networks in Japan deliver data rates up to 9.6 kbps for upload and up to 29.8 kbps for download.
PHS networks in Japan deliver data rates up to 128 kbps for terminals which are not moving at high speeds (e.g.PHS does not connect well in high-speed trains).
Third generation (3G) wireless networks in Japan deliver datarates from 64 kbps for upload and on the order of 200 kbos for downlad.Increasingly 3G networks in Japan are upgraded to deliver data connection rates on the order of 2 to 10 Mbps.These higher speeds allow the transmission of video and two-way video telephony,rapid download of movie sketches,music and JAVA applications.Other data connections,e.g.download of information or JAVA applets,are also several times faster on 3G networks then on older 2G networks.
In Japan there are three parallel,independent and competing 3G networks.Costs to the carrier are lower,so that competition drives prices down.2.Which networks are there in Japan and how many 3G users are there?KDDI/AU,NTT-DoCoMo and Vodafone operate 3G mobile networks in Japan.The following figure shows the user numbers as of January 2005:
2.What is the "killer application" for 3G?Is there one at all?If there is a "killer application" for 3G,its mobile music!Chaku-Uta downloads on KDDI-AU mobile phones have similar download numbers as iTunes in the US with a very much smaller potential user pool.One can therefore safely say,that mobile music downloads seem to be substantially more attractive for paying users than conventional fixed line internet music downloads.