Ofcom Ponders 100-200GHz Band for UK Fixed Wireless Links
We nearly overlooked this yesterday but Ofcom has proposed to enable greater access to around 18.2GHz of Extremely High Frequency (EHF) spectrum in the 100-200GHz range, which they feel could potentially be harnessed for very high speed data links, high precision industrial use (micro positioning of robots) or health screening etc.
Generally speaking adapting such a range for lower powered and / or licence-exempt fixed wireless links could be quite problematic. On the one hand you’d have a lot of spectrum frequency for data (extremely fast speeds would be possible), but on the other the signal would struggle to go any kind of distance and is very easily disrupted. However it’s not all about data connectivity and, as above, the bands could have many other uses.
Ofcom has so far identified three EHF bands that they consider could be suitable for coexistence with existing allocations and for internationally compatible devices, which might emerge in the future: 116-122GHz, 174.8-182GHz and 185-190GHz. These bands are currently allocated for primary use to Earth Exploration-Satellite Services, Inter-Satellite and Space research (passive).
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Ofcom’s Proposal for 100-200GHz
We propose that this spectrum could be accessed using:
• Lower power licence-exempt devices; or
• Increased power devices under a new ‘Spectrum Access: EHF frequencies’ licence on an uncoordinated shared basis.
To protect Earth Exploration-Satellite Services from the risk of undue interference, these devices would be authorised subject to certain technical conditions.
Ofcom added that they did “expect future licensed use of bands above 100GHz for fixed wireless links (radio communications between fixed terrestrial points, often used for mobile network backhaul)” too. Indeed the regulator’s previous 2018 review of spectrum noted how they “expected to include more short, high capacity connections, for use by smaller mobile cells and last mile fixed wireless access broadband services.”
We have our doubts about using these bands for fixed wireless broadband links but the regulator’s document is more akin to a hunt for ideas than a solid proposal. The consultation is open until 20th March and Ofcom then intends to publish their decision during summer 2020. In theory a new authorisation framework could be in place before the end of 2020.
Mark is a professional technology writer, IT consultant and computer engineer from Dorset (England), he also founded ISPreview in 1999 and enjoys analysing the latest telecoms and broadband developments. Find me on X (Twitter), Mastodon, Facebook, BlueSky, Threads.net and Linkedin.
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70-80 GHz works well for fixed wireless links, so would have thought the 116-122GHz band would be ok, as it is not massively higher.
Like the recent FCC decision on the 100+ GHz issue, Ofcom’s proposals miss the key point: The reason to go above 100 GHz is to get large continuous blocs of bandwidth. The biggest block in Ofcom’s proposals and FCC’s rules is 174.8-182 GHz or 7.2 GHz wide. In the US access is already available to 5 GHz at 71-76 GHz, so why go up to 170 GHz for a somewhat larger block?
While almost 26 GHz of 100-200 GHz is protected by bands strictly limited by ITU RR 5.340, the spectrum in 114.25-148.5 GHz is not. Neither FCC nor Ofcom mention why this big block is not being considered for timely access.