Wireless internet service

which should be designed to be the dominant service of 3G

requires down-link capacity several times higher than that of up-link. Initial 3G standards are the systems of symmetric up/ down-link capacity

existing serious technical limitations. Up to now

cdma2000 has already made some significant improvements by discarding cdma2000 3x standard and CDMA mode

then turns its steps to the method of EV-DO

which has TDMA mode; while WCDMA and TD-SCDMA standards have not made any corresponding changes. Needing to be pointed out

several system parameters of TD-SCDMA standard indicate that it is a mobile communication system applying to pedestrian environment. By using smart antenna technology could hardly change the basic features of the standard.