31 Jan 2012

Ofcom study points to spectrum shortages in sub-20GHz bands

Ofcom has just unveiled the results of an independent report which considers demand for frequency bands currently used by point to point fixed links over the next 5-10 years.

Analysis reveals sufficient spectrum will be available to to meet all anticipated future needs in bands above 20 GHz, but potential shortages may arise in bands below 20 GHz in some geographic regions.

The challenges in bands between 3 and 20 GHz are due the more limited availability of spectrum and demand growth arising from initiatives such as the rollout of mobile broadband and FWA into rural areas and the anticipated launch of a broadband public safety wireless network.

According to the study, carried out by Aegis, Ovum and DBSpectrum for Ofcom, considerable uncertainty exists over whether all or part of the 18 GHz band may be required to accommodate consumer satellite terminals in the future. If the whole or the majority of the band were to be re-allocated to satellite this could lead to congestion, particularly in the 13 and 15 GHz bands that are used for medium haul high bandwidth links.

Congestion may also arise in the 6 GHz and 7.5 GHz bands on a more localised basis, which could be relieved by greater use of the 4 GHz band. Ofcom notes, however, that the large antenna sizes required make this band less popular for fixed link deployment and that the propagation properties of the band make it potentially attractive for alternative uses such as mobile.

However, the regulators highlights the scope for more flexibility in this band, for example to permit more compact, less directional antennas or to allow geographic sharing between fixed and non-fixed applications.

Key trends likely to influence fixed link demand:

• cost and availability of fibre, particularly in urban and suburban areas

• demand for fixed wireless broadband access in rural areas

• launch and extent of coverage of 4G (LTE) mobile services

• roll out of a national public safety broadband network

• expansion of DAB coverage

• potential demand for satellite consumer terminals.

The study also pointed to two key developments that could lead to a step change in the demand for fixed links; the rollout of 4G (LTE) mobile services and the rollout of a national public safety broadband network.

As analysis showed, the latter is likely to have the greatest impact because of the necessity to deploy radio at every site (whereas 4G will mainly use fibre in urban and suburban areas) and because coverage is likely to be rolled out quickly to all areas of the country to meet the demanding needs of the public safety community.

The emergence of a real market demand for consumer satellite broadband terminals would also be significant. This could lead to demand for more exclusive spectrum for satellite in the 18 GHz band.

• Ofcom has initiated a call for input, to consider whether it should make changes to spectrum management policy across a number of bands between 1.4 GHz and 86 GHz that are currently available to fixed links.

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