 in ITU-R. URLs locating the specifications at each SDOs web and it is for that reason often referred to as the IMT-2000 archive. 'core band.' With the continuing development of the IMT-2000 Additional spectrum for IMT-2000 was identified at radio interfaces, including the evolution of UTRA to the World Radiocommunication Conference WRC-2000 Evolved UTRA, the ITU recommendations also need to in Resolutions 223 and 224, where it was considered that be updated. ITU-R WP8F continuously revises recom- an additional need for 160 MHz of spectrum for IMT- mendation M.1457 and at the time of writing it is in its 2000 was forecasted by ITU-R. The identification in- fifth version, with the sixth version awaiting approval. cludes the bands used for 2G mobile systems in 806-960 Input to the updates is provided by the SDOs and MHz and 1710-1885 MHz, and 'new' 3G spectrum in Partnership Projects writing the standards. the bands 2500-2690 MHz. The identification of bands In addition to maintaining the IMT-2000 specifica- assigned for 2G was also a recognition of the evolution of tions, the main activity in ITU-R WP8F is the work on existing 2G mobile systems into 3G. systems beyond IMT-2000, recently named IMT- The somewhat diverging arrangement between re- Advanced. This work includes studies of services and gions of the frequency bands assigned to 3G means that technologies, market forecasts, principles for standardi- there is not a single band that can be used for 3G roaming zation, estimation of spectrum needs, and identification worldwide. Large efforts have however been put into of candidate frequency bands for IMT-Advanced. defining a minimum set of bands that can be used to The spectrum work also involves sharing studies provide roaming. In this way, multi-band devices can between IMT-Advanced and other technologies in those provide efficient worldwide roaming for 3G. bands. The worldwide frequency arrangements are outlined in ITU-R recommendation M.1036. The recommenda- tion also identifies which parts of the spectrum 