Ofcom Identifies Candidate Spectrum for Future 5G Mobile Broadband

The United Kingdom’s telecoms regulator has today published an update on their preliminary work to design a regulatory approach for future 5G (5th Generation) based Mobile Broadband technology, which identifies several bands in different parts of the 6GHz to 100GHz radio spectrum range that could be candidates for the service.

Broadly speaking 5G will need to be diverse enough to operate in lower frequency spectrum than 6GHz, although most of the current solutions being developed or experimented on tend to operate in significantly higher frequency bands like 28GHz (here) or 73GHz (here); this is where you get the best / peak capacity speeds of 10Gbps+ (Gigabits per second).

At present Ofcom’s latest update notes that there is “no consensus amongst stakeholders” on specific bands to prioritise for further study, with some stakeholders indicating that it is currently too early to exclude any band for study. Never the less the regulator has identified several bands that it thinks would be “relatively straightforward to make available in the UK” (i.e. less conflict with other services and their international harmonisation goals).

Ofcom also said they were considering whether radio spectrum in other bands, such as 3.6 to 3.8GHz and 3.8 to 4.2GHz could be used for 5G.

Ofcoms Statement

“We think these bands may be relatively straightforward to make available in the UK compared to other options within the range 6 – 100 GHz (although the 10 GHz band is likely to be significantly more challenging than higher frequency bands) and could have potential for being harmonised and developed for future 5G use globally. However, this does not guarantee that these bands will be adopted in the future or preclude other bands being added.”

Meanwhile some trickier bands, such as 43.5 to 45.5GHz, 71 to 76GHz and 81 to 86GHz, are also being considered. But their use by existing services and technical restrictions make these more challenging than the above table.

Part of the aim here is to achieve 1GHz of bandwidth per operator for 5G, but some of the bands simply don’t have the spare capacity for that without creating problems for existing services. Apparently this was a particular problem for spectrum in the 6-30GHz range (e.g. Ofcom has so far only identified 2x100MHz at 10GHz), although it’s possible that this may still be “re-examined with a significantly lower bandwidth requirement” (e.g. 500MHz or 250MHz).

In any case the first commercial 5G deployment isn’t expected to surface until around 2020 and it’s hoped that some agreement on global harmonisation will be reached before then when the matter is discussed during future World Radio Communication Conference (WRCC) events in 2015 and 2019. At present all of this discussion is still extremely preliminary and subject to change.

At the same time one of the biggest challenges is with figuring out an economically viable approach to deploying 5G solutions at such high frequencies, which by nature do not travel very far and struggle to penetrate through walls; they can also be highly susceptible to other common environment factors like rain.

Over the past year we have seen some promising approaches, but turning these into viable solutions that have good coverage and which can also fit into modern ultra-slim Smartphones won’t be easy.