In short: A UK government-funded project proved that existing mobile network microwave links can detect rainfall by monitoring electromagnetic wave disruption — more accurately than radar, and with more detail than weather stations. No new hardware required.
Key Takeaways
- Existing infrastructure, new purpose — Vodafone's microwave links already span the landscape and can sense rain without any additional equipment
- Better than radar — The technique produces hyperlocal forecasts from minutes to hours ahead with greater accuracy than traditional methods
- Real economic impact — The River Severn region spends £230 million annually on flood infrastructure, and better forecasting directly reduces damage costs
In a nutshell
The Discovery
The River Severn Partnership — an eight-county region spanning England and Wales — was looking for better ways to predict flooding when researchers from Wireless DNA made an unexpected discovery. The microwave links that carry Vodafone's mobile network traffic between cell towers are slightly disrupted by rainfall. By monitoring the signal attenuation across thousands of these links, you can build a real-time rainfall map far more detailed than anything a radar station or network of rain gauges can provide.
The technique works because rain droplets absorb and scatter microwave radiation at the frequencies used by mobile backhaul (typically 15–40 GHz). The heavier the rain, the greater the signal loss. By correlating readings across many links simultaneously, the system produces hyperlocal observations and short-term forecasts — from minutes to hours ahead. Vodafone published the initial findings in detail, and the results were notably better than we had expected.
Why It Matters
Traditional flood warning systems rely on a combination of weather radar — coarse spatial resolution, updated every few minutes — and rain gauges, which are precise but sparse; the UK has around 3,500 tipping bucket gauges for the entire country. The mobile network approach fills the gap between these two: it offers the spatial density of radar with the accuracy of a gauge, and fundamentally, it is already deployed.
The River Severn region was chosen for good reason. The Severn is Britain's longest river, and its catchment area is particularly vulnerable to flash flooding from intense rainfall events. £230 million is spent annually on flood-related infrastructure management in the region alone. Even marginal improvements in forecast accuracy and lead time can save significant costs and, critically, give communities more time to prepare. The technology is promising, but we should note that translating trial-stage accuracy into operationally reliable national forecasting is a much more complex beast — the signal processing pipeline needs to handle link failures, hardware changes, and interference from non-rain sources, all of which become harder to manage at scale.
Recognition
The project won the UKTIN "Radical Breakthrough" award — recognition from UKTIN that the most transformative applications of mobile networks might not involve faster downloads at all, but rather using existing infrastructure as a sensing platform.
The approach is now being developed beyond the initial trial. If deployed nationally, every mobile operator's microwave backhaul network becomes a distributed environmental sensing grid — thousands of measurement points updating continuously, at no additional infrastructure cost. We believe this is one of the clearest examples of what happens when you treat connectivity infrastructure as a platform rather than a pipe.
The Wider Lesson
This is a pattern we see repeatedly in private and public 5G deployments: the most valuable use cases are often not the ones the network was built for. The infrastructure itself — the towers, the backhaul links, the edge compute — becomes a platform for applications nobody anticipated at planning stage. Consequently, building flexible, open networks that can support these emergent use cases is exactly why we invest in modern network architecture. The wider context here is important: whilst operators continue to chase consumer revenue, some of the highest-value returns may come from repurposing existing assets in ways the original business case never considered.