Telecoms regulator Ofcom is undertaking a consultation on the possible release of 700MHz spectrum for mobile broadband services in the UK, using spectrum currently assigned for digital terrestrial television (DTT) broadcasts.

The watchdog said that allocation of the frequencies “represents the most attractive option for providing additional lower frequency spectrum.” It notes they are already being used for LTE services in the US, with Asia, Australia and New Zealand planning to do similar, and India and others exploring this option.

Ofcom is already planning 800MHz and 2.6GHz spectrum awards, as well as supporting the re-farming of existing 2G mobile bands to 3G and LTE – not without some controversy.

With regard to digital terrestrial services, it was suggested that some 600MHz spectrum being released by the analogue switch-off could be repurposed for digital television, in order to free-up the 700MHz frequencies for mobile broadband.

In its document, Ofcom noted that across much of the world, 600MHz is harmonised for digital television, making this “the most likely attractive use of this spectrum.” Improvements in compression and transmission technology were also promoted as a way to improve broadcast efficiency.

The regulator has already seen some differences of opinion on its spectrum allocation plans, based on an earlier (April 2011) call for input.

Arqiva, Freeview and BT argued that digital television is currently the most popular broadcasting platform in the UK, and that it will “continue to remain highly relevant to UK viewers over the long term.”

In contrast, Vodafone, Everything Everywhere and Sky argued that this medium “faces fundamental challenges in the long term as consumer preferences evolve towards HD, 3D and non-linear video.”

In addition BT and Sky argued that mobile operators will not require spectrum in addition to the 800MHz and 2.6GHz allocations, with BT noting that increased use of small cells and Wi-Fi offloading can be used to meet increasing demand for indoor data.

Stakeholders have been invited to respond to the current consultation by 7 June 2012. It intends publishing a statement in Autumn 2012.