Spectrum is the range of radio frequencies a mobile network is licensed to broadcast on. UK networks bid for spectrum at Ofcom auctions and pay for the rights to use specific bands.
Why it matters
Different spectrum bands have different properties:
- Low band (700-900 MHz): travels far, penetrates walls — great for rural coverage
- Mid band (1800-2600 MHz): balance of range and capacity — most 4G/5G traffic
- High band (3.4-3.8 GHz): very fast, short range — for dense city 5G
- mmWave (24+ GHz): extreme speeds, very short range — barely deployed in UK
UK 5G spectrum
Most UK 5G runs on 3.4-3.8 GHz mid-band. Some low-band 5G uses 700 MHz for rural reach. mmWave 5G isn't commercially deployed in the UK yet.
Why this affects coverage
A network with lots of low-band spectrum (Vodafone, O2) has better rural reach. A network with lots of mid-band (EE) has better urban speed. Multi-network plans like Fuse combine the best of both.
See also
How Spectrum matters when picking a UK mobile plan
Understanding Spectrum helps you compare mobile providers on a like-for-like basis. Most consumer mobile pricing pages skip the technical detail — knowing the terminology means you can spot when a plan is genuinely better and when it just sounds that way. The Fuse Mobile glossary keeps definitions short and consumer-focused, no jargon-on-jargon.
Fuse Mobile is a UK multi-network data-only eSIM — it gives your phone access to all four UK mobile networks (EE, Three, Vodafone, O2) through a single profile. Where Spectrum is relevant to that setup, it's surfaced explicitly: pricing pages show real numbers, the coverage checker shows live per-network signal, and there's no hidden fee structure. See the plans page for the current pricing or read the multi-network eSIM explainer for the technical detail.