Originally featured on BroadcastEngineering.com
U.K. surrenders 700MHz spectrum to mobile
The UK has become one of the first European countries to formally give up the 700 MHz band to mobile services and start preparing to move DTT services down to the 600 MHz band. Regulator Ofcom has announced that this spectrum has been awarded to the only bidder, UK digital terrestrial multiplex operator Arqiva.
This was welcomed by Arqiva, which stated that it would provide capacity for an extra 10 HD channels over the UK’s Free to Air digital terrestrial service partly because it would be associated with the more efficient second-generation DVB-T2 standard incorporating improved Forward Error Correction as well as compulsory H.264/MPEG4 encoding. But broadcasters such as the BBC, which transmit over Arqiva’s infrastructure, were less enthusiastic, arguing that there should have been more debate before agreeing to give up the 700MHz band to mobile services. Their point, strongly supported by the European Broadcasting Union (EBU), is that regulators should be encouraging moves toward shared use of spectrum between broadcasters and mobile operators, because both will continue to provide vital services that can be more efficiently delivered in the long term through common approaches to spectrum allocation and usage. The EBU contends that unicast delivery within mobile services is highly inefficient for popular linear video content as it consumes multiple end-to-end paths simultaneously and will not be sustainable given finite radio spectrum and only limited scope for further improvements in efficiency.
But this argument has not been bought by the EU (European Union) or most national regulators. Indeed Ofcom itself made its intentions clear over a year ago in April 2012, when it launched a consultation over allocation of the 700MHz band spectrum for mobile broadband services in the U.K.
The regulator said then this would bring the U.K. into line with a number of other markets including the U.S., which was deploying LTE at 700MHz on a large scale. Ofcom was clearly supporting the mobile camp with its argument that a common frequency band for global LTE services was vital for handset makers to limit the cost and complexity of manufacturing devices for multiple markets. At that time there were 42 different bands allotted for LTE worldwide.
DTT itself is also fragmented, with four global regions and increasing momentum behind the idea of unifying those. But the broadcast community is concerned that by the time agreement is reached there will only be scraps of spectrum left for them to negotiate over. In the more immediate future the issue is more to do with planning for yet another move down the spectrum ladder to lower frequency, which increases the potential range but at the expense of potential problems over antenna size, antenna performance, and use of Multiple-Input-Multiple-Output (MIMO) for performance and robustness. Mobile device makers have been packing antennas closer and closer together to reduce size, which is harder to achieve at lower frequencies and therefore longer wavelengths that require greater distances between antennae for MIMO to work. That is another reason mobile operators would rather have the 700MHz band in the range 694MHz to 700MHz than the 600MHz band between 550MHz and 606MHz.
DTT operators could say the same because their ability to serve mobile devices may also be impaired, or at any rate, require additional investment. But they will have to accept it because other European countries are likely to follow the U.K. by moving DTT down to 600MHz. At least broadcasters and DTT infrastructure providers will have several years to prepare, until 2018 in the case of the U.K., until when Arqiva will continue to have the 700MHz band as well.