Digital UK, the body responsible for supporting DTT in the UK, has published a study, The defragmentation dividend – A more efficient use of the UHF band, which outlines options to deliver a major boost in spectrum capacity for mobile broadband services.
The study, by telecoms specialist Aetha Consulting, explores the scope for a fundamental rethink of how UHF spectrum is used by mobile operators. The report estimates that the changes could unlock a capacity increase of up to 70 per cent.
UHF frequencies are prized by both broadcasters and mobile operators as they travel long distances and provide good indoor reception. Over the last 10 years, DTT services such as Freeview have been required to give up UHF spectrum to help meet demand for mobile data.
The 700MHz band is the latest slice of spectrum being re-allocated to mobile, incurring significant costs to UK taxpayers and reducing the amount of spectrum available for Freeview and other terrestrial TV services by one-third. Freeview is the most widely used TV service in the UK, watched in around 19 million homes. Across Europe, around 250 million people use a DTT service.
The report highlights how the incremental process of change has produced a fragmented plan for mobile broadband in the 700, 800 and 900MHz bands. Simplifying the use of these frequencies could produce a ‘defragmentation dividend’ of 25 per cent -70 per cent, while also future-proofing the spectrum for new technologies, including 5G.
The report explores three illustrative options, including a shift from existing Frequency Division Duplex (FDD) transmission, which provides equal capacity for the uplink and downlink, to Time Division Duplex (TDD) arrangements. The use of TDD would increase downlink capacity to accommodate activities such as video streaming. The report makes clear that the maximum gains would need to be planned over the long-term (beyond 2030) as other users of the bands may need to be re-located.
“The time has come to take a more strategic view and move beyond the approach of ‘salami slicing’ DTT spectrum to create capacity for mobile data,” declared Jonathan Thompson, CEO of Digital UK. “Any further cuts to television airwaves are likely to lead to a lose-lose outcome that damages Freeview and creates even greater inefficiency. The proposals in this report offer the prospect of a win-win situation, which sees a major boost for mobile capacity while safeguarding the UK’s most widely used TV service.”