ITU-R spectrum demand calculation for IMT-Advanced

The determination of spectrum demand of future wireless systems represents an important step in the process of defining and standardizing the systems. Spectrum-related issues will play a key role in the development of future wireless systems due to the increasing bandwidth demand to meet the requirements of future services in the current spectrum regulatory framework where most of the spectrum is already allocated to different services. The radio spectrum is globally administered by the International Telecommunication Union (ITU) whereas the use of radio spectrum in each country is nationally regulated by the corresponding government agencies that have the freedom to make the spectrum available for particular uses in their operational area. The ITU Radiocommunication sector (ITU-R) arranges the World Radiocommunication Conference (WRC) every three to four years to review and revise the Radio Regulations, which are the international treaty governing the use of the radio spectrum and satellite orbits. Recent decisions on spectrum use, including spectrum for the mobile service, were made at WRC-07 with new spectrum identifications for International Mobile Telecommunications (IMT) systems. The demand for additional spectrum for IMT systems was justified by a spectrum requirement calculation methodology that was used to estimate the total spectrum demand of IMT systems in the time span 2010-20. This chapter gives background information on the ITU-R activities that led to the decisions on new spectrum identifications for IMT systems taken at WRC-07. The chapter introduces the role of the ITU-R in the spectrum regulatory framework and reviews the ITU-R preparatory work for WRC-07 on the frequency-related matters of IMT systems. The main emphasis is on the ITU-R spectrum requirement calculation methodology that predicted the total spectrum demand of IMT systems in 2010 to 2020. The methodology is a result of truly international cooperation and the major parts of the methodology originate from the WINNER project. This chapter reviews the spectrum requirement calculation methodology including the input parameters, processing steps and the software implementation of the methodology that was used to perform the actual calculations for deriving the spectrum demand. Finally, the ITU-R results of the spectrum requirement calculation studies are reviewed together with the final decisions on the spectrum identification for IMT-Advanced made at WRC-07.