CHAPTER 4.1 Background of 3G evolution ITU-R Family of IMT-2000 Terrestrial Radio Interfaces (ITU-R M.1457) IMT-2000 CDMA Direct Spread IMT-2000 (UTRA FDD) CDMA Multi-Carrier (CDMA2000) 3GPP 3GPP2 3GPP IMT-2000 TDMA Single-Carrier (UWC 136) ATIS/TIA ETSI IMT-2000 FDMA/TDMA (DECT) IMT-2000 CDMA TDD (UTRA TDD) Figure 4.1-4 The definition of IMT-2000 in ITU-R. URLs locating the specifications at each SDOs web archive. With the continuing development of the IMT-2000 radio interfaces, including the evolution of UTRA to and it is for that reason often referred to as the IMT-2000 `core band.' Additional spectrum for IMT-2000 was identified at the World Radiocommunication Conference WRC-2000