20 June 2025
Network analyst firm Streetwave has released findings from a recent survey assessing the signal coverage and data performance of the UK’s leading mobile networks — EE, Three UK, Vodafone, and O2 — within St Mary’s Hospital in London.
Conducted on June 17, 2025, the survey focused on the hospital’s public walkways, specifically around the QEQM Building, with data collected via portable equipment at 12:33 pm. While the results are anecdotal due to the limited survey scope, they provide a useful snapshot of indoor mobile network performance in a critical public healthcare setting.
Streetwave measured key indicators such as throughput speed, signal strength, network generation, and frequency band across all four major UK operators. The data was used to calculate two coverage metrics: ‘Acceptable Coverage,’ which reflects locations where users can expect download speeds of at least 5 Mbps, uploads of 2 Mbps, and latency below 40ms, and ‘Essential Coverage,’ indicating areas providing at least 1 Mbps download, 0.5 Mbps upload, and latency below 100ms — enough for basic internet use.
The results show that overall, O2 (Virgin Media) and EE (BT) jointly delivered the strongest Acceptable Coverage at 21%. Vodafone’s acceptable coverage was slightly lower at 17%, while Three UK recorded a modest 7%. In terms of Essential Coverage, which indicates more basic connectivity, O2 led at 66%, followed by Three UK at 60%, Vodafone at 43%, and EE at 42%.
Most hospitals typically offer public WiFi networks, but these can be costly and sometimes underperforming. Mobile broadband presents a viable alternative, especially for staff and visitors needing reliable connectivity. However, indoor coverage remains a significant challenge, and some hospitals might view strong mobile signals as a threat to their paid WiFi services, potentially impacting future investments in indoor mobile infrastructure.
While the survey provides only a snapshot, it underscores the ongoing difficulty of achieving consistent indoor mobile coverage in large institutional buildings like hospitals — highlighting a key area for network improvement in the UK’s digital infrastructure.
