sting frequency bands New 2 GHz frequency band 900, 1800, 1900 MHz New modulation in existing New 5 MHz WCDMA air 200 kHz TDMA air interface interface Simple migration with New technology optimized plug-in compatible for wide band services and transceiver units minimum cost Figure 13.26 Some data on EDGE and WCDMA Introducing EDGE is a capacity upgrade of the radio interface reusing what is already implemented for GPRS. Therefore, the additional complexity of GPRS-EDGE cannot be compared to the sig- nificant evolution from GSM to GPRS. Figure 13.26 compares EDGE and the next evolution step WCDMA, creating a bridge to next subject. Access Network 13.11.4 WCDMA/UMTS Two basic approaches in this book are the all-access network architecture and ROCE as a profitability tool. This implies a modern 3G/NGN oriented core network and a multi- tude of new and existing access types. It means also that the UMTS core characteristics are part of many chapters in the book. Chapters 3, 5, 7, 8, 9, 11, 12 and 14 are such examples. The development track GSM-GPRS-UMTS is briefly described in Chapter 8, section 8.2. The UMTS access does not have a corresponding strong position on the fragmented access side, but a strong expansion is expected. The business case is carefully studied and developed with ingredients such as network sharing between operators, shar- ing of resources between access technologies and intersystem (for example GSM-UMTS) roaming. The WCDMA access for UMTS is schematically shown in Figure 13.27. 13.11.5 WCDMA RADIO ACCESS NETWORK (UTRAN) The WCDMA radio access network, known as UTRAN (universal terrestrial radio access network) will provide access speeds at up to 2 Mbit/s in the local area and up to 384 kbit/s wide area access with full mobility. These increased data rates compared with GSM/GPRS require a wide radio frequency band, which is why WCDMA with 5 MHz carrier has been selected, compared with 200 kHz carrier for narrowband GSM. The new frequency allocation is shown in Figure 13.28. To begin with, voice wi