ANALYSIS The Ministry of Defence (MoD) has today announced it is to sell part of its radio spectrum. Digital terrestrial television multiplex operators have suggested that the extra spectrum should be fully utilised by mobile networks before more frequencies are taken away from terrestrial television.
The sale of the MoD spectrum is to take place in 2014, with mobile networks invited to purchase additional spectrum to complement their 4G spectrum. Unlike the 800 MHz 4G service that will roll out next year, use of the MoD spectrum is not expected to affect TV signals.
Ofcom meanwhile is driving ahead with plans to remove more spectrum from TV broadcasters so that even more bandwidth is available for mobile internet. Unlike the MoD spectrum, Ofcom will have to reach agreements with neighbouring countries before it can clear TV frequencies, to avoid interference problems.
Earlier this year, in a response to an Ofcom consultation on the future of the UHF TV frequency band, the digital TV multiplex operators stated: "the higher frequencies [e.g. the MoD spectrum] would offer a similar benefit to mobile
operators because we believe that congestion is likely to materialise in
densely populated urban areas. The amount of spectrum available in 700
MHz [current TV frequencies] would deliver insufficient capacity, and therefore other high
frequency bands – with more bandwidth availability per operator – would
be better suited for mobile broadband capacity purposes."
The argument is that the spectrum / frequencies being sold off by the MoD are more suitable for areas where there is likely to be localised high data demand - areas where the 700 MHz TV frequency band would not provide sufficient capacity.
Frequencies currently used by TV services are favoured because they enjoy better coverage and penetration into buildings. Less masts are required to cover a wider area. However, capacity is reduced - each mast could potentially have to cover more users, so less capacity is available to go around. Higher frequencies offer more capacity in local hot spots, such as in towns and cities and especially commuter destinations such as railway stations, major road junctions and service stations, where wi-fi can complement mobile networks.
Although additional mobile broadband capacity on the UHF TV frequency band would suit rural areas, it is often the case that existing available spectrum is not being fully utilised yet, resulting in many rural not-spots with no or poor mobile coverage and definitely no 3G coverage let alone 4G.
Some argue that the drive to clear the 700 MHz band is purely driven by a desire to harmonise frequencies used for mobile data services with other parts of the world, such as North America and the Asia Pacific region rather than the real need to use the 700 MHz band for data to prevent a future "data crunch".
Any further reductions in the available frequencies for TV services is not planned until at least 2018, when the impact of the MoD spectrum sell off will be known and negotiations with neighbouring countries over the future use of the UHF TV band will have concluded.
Multiplex operator's response to Ofcom quoted in the above article:
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