Friday, 09 January 2009 
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2.3 Existing bands are not enough to satisfy the spectrum demand for IMT-Advanced

Mobile applications and services, with the foreseen increase in data volumes, are demanding the peak data rates of the order of 100 Mbps to 1 Gbps and cannot be provided satisfactorily within today’s IMT-2000 spectrum bands:
  1. The demand for increased traffic:
    These new and more advanced services will render the traffic to increase and therefore, two possibilities could be envisaged: to increase density of base stations, or to increase the spectrum available. It is important to note that there are practical limitations for the density of base stations, since there are cost (CAPEX and OPEX) issues and environmental deployment issues, as e.g. towers and antennas cannot be built at any location. Notably, the current UMTS networks are already today deployed with a very dense separation of around 500 meters in central business districts.

  2. The demand of higher data rates:
    The expectations and demand for very high peak data rates require new radio technologies, which are able to use wider bandwidths (possibly 100 MHz per channel and per operator) than commonly used today (5 MHz per channel, which can be arranged in wider blocks typically about 10 – 15 MHz per operator).

Based on the Forum Report 37 “Magic Mobile Future 2010 -2020”, the Forum has calculated the future mobile spectrum requirements, which has been published as UMTS Forum Report 40 . The study concludes that, if the predicted traffic projections were materialized, the spectrum requirements for mobile services would be much larger than the amount of spectrum currently allocated for cellular and mobile use. Using the traffic forecasts in the Report 37 “Magic Mobile Future”, the study concludes that the total demand for mobile spectrum will be an amount of about 1.6 GHz by year 2020 including spectrum already identified for UMTS/IMT-2000, 585 MHz in Europe2 , see Figure 3.

Figure 3. Spectrum requirements calculated using the spectrum forecasts in Europe2) (Source: Forum Reports 37 and 40, EU FMS-study3 )

The 19th meeting of ITU-R WP8F in Biarritz in May 2006 approved the Report ITU-R M.2078. The calculations in this report resulted in two total mobile spectrum requirement figures for year 2020, one for lower market and one for higher market. The spectrum requirement for the lower market is 1280 MHz and for the higher market 1720 MHz. Both calculations assume a single network deployment and indicate a total spectrum requirement for both the Radio Access Technology Group (RATG)1 (i.e. pre-IMT, IMT-2000, and its enhancements) and RATG2 (i.e. IMT-Advanced), including spectrum already in use, or planned to be used, for RATG1. The expected increase in spectrum efficiency for the future technologies was estimated in this Report to be very optimistic.

These results show clearly that additional mobile spectrum is needed, beyond that identified for IMT-2000 at WARC-92 and WRC-2000.

2 The spectrum currently identified for cellular use in Europe is 585MHz and includes the 900MHz and 1800MHz GSM bands, the 2GHz UMTS band (including the band that is currently used for DECT), and the 2.6GHz expansion band.
3 The estimations of the FMS Study cover mobile, nomadic and broadcasting environments, i.e. all four RATgroups identified by ITU-R WP8F.



 
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