Ofcom UK Confirm Changes to 3.9GHz Band for 5G Mobile and Wireless Broadband

Ofcom has introduced changes to its existing licence for the 3.9GHz (3925 – 4009MHz) radio spectrum band, which among other things will adjust the authorised frequency from 3925-4009MHz to 3800-3884MHz (i.e. making it more efficient) and allow Three UK (VodafoneThree) to harness it for fixed wireless and 5G based mobile broadband services (Three Home Broadband).

In case anybody has forgotten. Mobile network operator Three UK previously asked Ofcom (here) to consider making a useful technical change to its existing licence for the 3.9GHz band. This is held by their sibling UK Broadband Limited company, but was previously only intended to be used with 4G fixed wireless services.

Ofcom have now completed their consultations on this request and granted a number of changes, which should also improve spectrum availability for Shared Access users (i.e. spectrum sharing with smaller or private network projects etc.).

Ofcom’s Changes for the 3.8 – 4.2GHz Band

To achieve more efficient use of the 3.8 – 4.2 GHz band than at present, we have decided to:

• Vary the technical terms in the 3.9 GHz licence in line with H3G’s request to support the use of 5G technology to enhance its FWA offering (the licence will continue to be limited to fixed use);

• Introduce a requirement for H3G to use the spectrum ‘assignments’ that it requests (a ‘use clause’), which will enable us to remove unused assignments – freeing up unused spectrum for use by other users. This requirement will be phased in over five years.

• Change the technical assumptions used for coordinating H3G with Shared Access users, which will improve spectrum sharing by reducing the geographical area that each of H3G’s assignments prevents from being used by Shared Access users.

• Move the 3.9 GHz licence to the bottom of the 3.8 – 4.2 GHz band by changing the permitted frequencies from 3925 – 4009 MHz to 3800 – 3884 MHz. We will also ask Shared Access users currently overlapping with the 3800 – 3884 MHz frequency range to retune (within 18 months) to frequencies above 3884 MHz. These moves will improve spectrum efficiency by placing H3G’s assignments at the bottom of band rather than in the middle, thereby reducing fragmentation and increasing the total amount of useable spectrum for Shared Access users.

The planned move of Shared Access users is in line with the conditions in all Shared Access licences which require equipment to be capable of transmitting across the relevant band (in this case 3.8 – 4.2 GHz) and enable Ofcom to change the frequency authorised within the band. However, recognising stakeholder feedback, we are providing options for Shared Access users to remain at their current frequency for longer to facilitate their frequency move

The regulator adds that Shared Access users will also have the option not to move (retune) if they have reached a coordination agreement with Three UK or if they are happy to accept the risk of interference when Three UK deploys the change, but they must inform Ofcom of their choice within 90 days. “If they remain at risk, they will receive advance notice from H3G of any deployment that causes interference to them,” added Ofcom.

However, despite the changes, Ofcom has highlighted how several market and regulatory developments relating to this band could still result in them changing their approach in the future. For example, the EU is working on harmonisation of the band for private and local networks, while the USA is exploring the use of 3.98 – 4.2 GHz for high-power mobile, among other things.