Summary

  • Ofcom’s 2018–2024 totals describe coordinated assignments in licensing records; they are not a direct count of transmitters on air or interference experienced.
  • At Glastonbury in 2024, 759 day-long assignments, a 491-assignment whole-site simultaneous peak and 187 local-zone frequencies describe three different planning scales.

The first number that matters in Ofcom’s review is not a forecast. It is a distinction. At Glastonbury, the regulator counted 759 microphone and in-ear monitor assignments across a busy day in 2024. At 21:30, when Coldplay began its Pyramid Stage set, 491 assignments were in use simultaneously across the festival site. Around the stage, where nearby equipment could not reuse the same frequencies, Ofcom calculated a local peak of 187 unique frequencies within 300 metres. With a 10 per cent contingency, that planning figure became 206. All four numbers are defensible; none is a substitute for the others. Ofcom’s updated call for input explains the time and location assumptions behind them.

That separation matters because “spectrum demand” can be made to sound like one national quantity. For microphones and in-ear monitors, the operating constraint is local and simultaneous: which frequencies can work in the same place, at the same time, without unacceptable interference? A festival may need hundreds of assignments over a day, but it can reuse a frequency at another stage or after one performance ends. A national total helps describe the scale of licensing and coordination. It does not itself tell a regulator how much clean spectrum a particular stage needs at 9:30 p.m.

Ofcom’s historic comparison is still useful. Its report says total coordinated assignments rose from 302,374 in 2018 to 370,275 in 2024, an increase of 22.5 per cent. Because lockdowns suppressed activity in 2020 and 2021, Ofcom excludes those years when calculating a four-year compound annual growth rate; on that basis, total assignment growth was 5.2 per cent a year. Microphone and in-ear monitor assignments rose 31.6 per cent across the period, while licensed bandwidth for wireless video rose 35.6 per cent. These are indicators of growing demands on the licensing and planning system, not measured increases in occupied radio channels.

The records have real value. Ofcom’s data-release note describes 724,907 microphone/IEM rows and 99,525 video rows for 2018–2024. The published fields include equipment category, permitted frequency and bandwidth, location reference, and licence start and finish. Ofcom removed licensee names. That is a substantial and reusable administrative dataset. Yet an assignment is still a permission and planning record. It does not establish, by itself, how many microphones in a licensed block were actually switched on, what power they used, how often a device had to retune, or whether an audience heard interference. The release note documents the fields and the assumptions behind the summary tables.

One assumption makes the boundary especially clear. When a licence covers an entire 8 MHz channel, Ofcom’s analysis assumes that it accommodates ten microphones or IEMs; for a 4 MHz channel, it assumes four. Those are modeling assumptions for turning licence widths into assignment counts, not a claim that every licensee runs exactly that number of devices. In a 2024 response, the National Theatre said it licences whole 8 MHz bands on an annual schedule and Ofcom does not receive a count of the microphones actually used in each channel. It reported roughly 222 channels of radio equipment at the venue, most used daily, and argued that professional audio quality and latency limit some efficiency claims for newer systems. That is a stakeholder’s evidence, not an independent measurement of the whole sector—but it shows why a licence-based count and an equipment inventory should not be presented as the same thing. The National Theatre’s response was added to the consultation page on 29 September.

There is also a persuasive case for Ofcom’s planning approach. Its report says it can currently satisfy PMSE demand and that careful coordination, denser packing and changes in shared use helped absorb growth. At Glastonbury, the regulator compared a theoretical 72 MHz requirement—including a 10 per cent contingency—with 168 MHz across 21 outdoor UHF television channels. But Ofcom immediately cautions that this is not a practical capacity guarantee: intermodulation, the tuning ranges of different devices and late changes to performers make some channels harder to use efficiently.

A theoretical channel count can identify room for better planning; it cannot erase the constraints of production equipment or the need for robust audio at a live event.

The review is therefore not a contest between “there is enough spectrum” and “there is not.” Ofcom says it has so far met demand; the industry points to growth, equipment limits and uncertain long-term access. Both statements can be true. The question is whether the evidence available can tell the regulator where the constraint sits: in total licensed bandwidth, a local peak, scheduling practices, device compatibility, interference risk, or the ability to forecast a future production.

That question will matter as television distribution evolves. PMSE uses parts of the UHF spectrum alongside digital terrestrial television. Ofcom says a future DTT decision could affect some of those frequencies, although major change is unlikely before the 2030s and several UK-wide multiplex licences expire at the end of 2034. The consultation also lists possible ways to study access elsewhere, including temporary or geographic sharing. Those are options for examination, not announced allocations.

A spectrum decision made on the basis of annual licence totals alone could miss a local constraint; a decision based on one festival peak could overstate a nationwide need. Both errors would be avoidable if the measures were labelled by what they actually observe.

Ofcom’s review has already done one useful thing: it has published assumptions, data fields and event-level examples that readers can interrogate. The next step is to preserve that distinction in any future statement. “Licensed assignment,” “daily total,” “simultaneous site demand,” “local reuse-zone frequency need” and “observed transmission or interference” should remain separate measures. Where the last category cannot be measured, that absence should be explicit rather than filled by a model that appears more precise than its inputs.

For spectrum policy, the hard resource is not only MHz. It is reliable evidence about who can use which frequencies, where, when and with what operational constraints. Ofcom’s assignment records establish part of that picture. They do not close it.

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