ll probably continue to be transferred in the GSM networks of the 3G operators, but voice will also be efficiently carried over WCDMA. UTRAN consists mainly of radio network controller (RNC) nodes and radio base sta- tion nodes. The RNC manages radio access bearers for user-data transport, manages and optimizes the resources of UTRAN and controls mobility. Other parts are the radio access network operation support (RANOS) and tools for radio access management (TRAM). The RNC is connected to the core network via the Iu interface. Internally within radio Access External equipment network network networks GSM access UMTS access Intranet Extranet Internet Figure 13.27 The WCDMA/UMTS access network architecture Understanding Changing Telecommunications - Building a Successful Telecom Business UMTS spectrum: FDD & TDD mode Duplex distance: 190 MHz Frequency TDD = Time division duplex [MHz] FDD = Frequency division duplex MSS = Mobile satellite service UL = Uplink DL = Downlink DECT = Digital enhanced cordless telecommunications Figure 13.28 WCDMA/UMTS access network (UTRAN) utilizes a new frequency band above 2.1 GHz Other management Core network -systems Network management systems RANOS Tools for radio Radio network access management Radio access controller network Subnetwork manager of WCDMA RAN Services Radio base station WCDMA RAN customer services User equipment Figure 13.29 The WCDMA/UMTS access network access network, the RNCs are interconnected via the Iur interface and the radio base stations to the RNC via the lub interface. See Figures 13.27 and 13.29. The RNCs are the central intelligence of UTRAN and will have even more functionality than GSM base station controllers. The radio base station provides the actual radio resources. Access Network The RANOS software package takes care of day-to-day operation and maintenance. The position is shown is Figure 13.29. 13.11.6 CDMA Within the CDMA2000 standard, several phases have been defined to support the ITU requirements for third-generation services. Figure 13.30