Ofcom UK Propose Tweak to 3.9GHz Band for Mobile and Wireless Broadband

The UK telecoms regulator has proposed an additional tweak to its existing licence for the 3.9GHz (3925 – 4009MHz) radio spectrum band, which would change the authorised frequency from 3925-4009 MHz (3.9GHz) to 3800-3884 MHz (3.8GHz). This could potentially make it more efficient for fixed wireless and 5G based mobile broadband services, such as those from Three UK.

Just to recap. Mobile operator Three UK (H3G) previously asked Ofcom, in May 2024 (here), to consider making a useful technical change to its existing licence for the 3.9GHz band, which is held by their sibling UK Broadband Ltd. The change, if approved, would enable them to use this band with 5G technology to boost their Fixed Wireless Access (FWA) broadband packages (Three Home Broadband).

The regulator is currently still consulting upon the above proposal, but as part of that they have also considered feedback from respondents who felt that changing the authorised frequency from 3925-4009 MHz (3.9GHz) to 3800-3884 MHz (3.8GHz) “could make use of the wider 3.8-4.2 GHz band more efficient“.

Ofcom had previously shelved this idea because, while they “recognised there were benefits” (i.e. an increase in the amount of usable spectrum and possible removal of fragmentation in the band for Shared Access users), a frequency move would have also made some of Three UK assignments “incompatible with existing Fixed Links in SE England and a significant number of Shared Access users“.

However, the regulator now believes that they can find solutions for the aforementioned concerns, particularly after Three UK supported the idea and suggested that it could “potentially lower its equipment costs”. The operator was also able to offer “mitigations to minimise the impact the move would have on incumbent users”.

In addition, the BBC and Neutral Wireless (both Shared Access users) both supported the move, citing how it would increase spectrum availability and efficiency, offering more contiguous spectrum, with only one spectrum boundary for Shared Access users rather than three.

Ofcom’s New Proposal for 3.9GHz

Alongside the changes previously outlined in our May 2024 consultation, we are seeking views on an additional option to vary the terms of the 3.9 GHz licence by changing the permitted frequencies from 3925-4009 MHz to 3800-3884 MHz. This could potentially deliver more efficient use of the radio spectrum by:

• increasing the total amount of useable spectrum for Shared Access users by reducing the number of boundaries with high power users; and

• reducing fragmentation in the 3.8-4.2 GHz band, so that Shared Access users wanting to use higher bandwidths are more likely to be able to get a licence for the channel width they require.

To support efficient use of the band, we would ask Shared Access licensees currently overlapping with all or part of the 3800-3884 MHz frequency range to retune their equipment to alternative frequencies above 3884 MHz. This is in line with the condition in all Shared Access licences which enables Ofcom to change the frequency authorised and our guidance requiring Shared Access users to be frequency agile (i.e. licensees in the 3.8-4.2 GHz band should deploy equipment that can tune across the entire band). We would identify suitable alternative frequencies for these licensees and allow 18 months for the move.

Ofcom’s new consultation will remain open until 25th February 2025, and they plan to publish a statement setting out their final decisions during next Spring 2025.