It is not sufficient to refarm spectrum from broadcasting and other uses to cellular on a purely national basis. Global or at least regional coordination and harmonisation of spectrum band allocations are needed to minimise cross-border radio interference, maximise economies of scale for devices and facilitate roaming.
Finding 1200 MHz for mobile broadband
The mobile broadband revolution with data traffic doubling each year has created an urgent need for additional spectrum. The European Commission has set a most challenging goal of identifying at least 1200 MHz for wireless broadband services. Finding spectrum that can also be harmonised across Europe is particularly important and challenging--significantly in the most attractive lower bands below 2 GHz where radio propagation is best and network coverage can most cost-effectively be established.
Beyond refarming mobile spectrum that is currently used for 2G and 3G services, broadcasting frequencies are the primary target for acquiring additional mobile spectrum below 2 GHz. Finding spectrum in some nations is rather more difficult than in others for historic reasons. For example, Benelux nations may be most willing to relinquish broadcasting spectrum because they have for many years distributed TV to the vast majority of households via cable systems: household TV aerials have mostly disappeared. Terrestrial TV is only used regularly by a very small minority there. In other nations--including France, Italy and the UK--a large proportion of the population still primarily watch terrestrial TV, even if they have cable or satellite service in their living rooms. There will be much greater resistance to broadcasters giving up spectrum a terrestrial channels in those nations.
The newly available "digital dividend" spectrum at 800 MHz spectrum is a vital addition that has been harmonized across Europe. It is being cleared for LTE licensing with the switchover from analogue-to-digital. This was a relatively easy gain due to the greatly improved spectrum efficiency of digital (using MPEG-4/AVC codecs) over analogue TV. Spectrum was released despite increasing numbers of TV channels. According to BBC sources, in the UK, 800 MHz spectrum clearing entailed moving just two channels (61 & 62), involved 230 transmitters and took three years to complete. However, a total of 2 x 30 MHz, as is due to be auctioned soon in the UK, is only a small proportion of the total demanded by the European Commission.
Additional TV channels in the 700 MHz band are also urgently required, and are set to be refarmed, but there are significant challenges. This change will require broadcasters, in at least some nations, to use more bandwidth-efficient DVB-2/HEVC codecs. The ambitions of terrestrial broadcasters in using HD more extensively and adopting Ultra-HD will need to be curtailed. Clearing the 700 MHz band is a much bigger task than with the 800 MHz band. In the UK, it will involve 1,342 transmitters and require replacement of a large proportion of roof-top TV aerials.
Consensus and coordination
Despite the difficulties and costs (that are small in comparison to the economic value of the spectrum), it is essential that the TV re-banding and spectrum clearance occurs as quickly as possible across the whole of Europe. Studies reveal that cross-border radio interference effects will be most harmful if some nations stick with digital TV and others re-allocate the spectrum to mobile. The relatively high-powered TV transmitters in an uncoordinated band structure across borders would play havoc with mobile receivers. Mobile network and handset transmitters will significantly disrupt TV sets. These problems would extend far beyond the border zones and right across some of the smaller nations. A mobile broadband refarming patchwork is not an option in Europe.
Whereas device banding and international roaming have been fairly straightforward in recent years with relatively small numbers of widely used radio bands in GSM (e.g., including 850, 900, 1800, 1900 MHz), and UMTS (e.g., including 850, 1900, 2100 MHz), LTE has immediately spawned dozens of bands. Device support for LTE bands is therefore also very fragmented. For example, the iPhone 5 supports LTE at 1800 MHz but not LTE at 800 MHz (which was originally regarded as Europe's primary LTE band). A strong and broad alignment around a new 700 MHz band structure and a corresponding band class for devices in Europe will ensure availability of a wide variety of low-cost devices that are most appealing to those that stay in their home nations and also for mobile broadband border hoppers.
Keith Mallinson is a leading industry expert, analyst and consultant. Solving business problems in wireless and mobile communications, he founded consulting firm WiseHarbor in 2007. WiseHarbor publishes an Extended Mobile Broadband Forecast. This includes network equipment, devices and carrier services to 2025. Further details are available at: http://www.wiseharbor.com/forecast.html. Find WiseHarbor on Twitter @WiseHarbor.