Summary

• There are three main 3G systems: W-CDMA, cdma2000, and EDGE. They are collectively known as IMT-2000 and will offer packet-switched data at rates exceeding 384 kbps.

• W-CDMA is designed to be backward-compatible with GSM, and requires new spectrum. It is also known as UMTS.

• cdma2000 is a straightforward upgrade to cdmaOne, but itself consists of two competing proposals.

• EDGE is a straightforward upgrade to GSM and is also compatible with other TDMA systems, such as D-AMPS and PDC.

• The first 3G systems are being deployed in Japan, using W-CDMA technology.