Ofcom scored the four mobile network operators (MNOs) using data collected from network performance analyst RootMetrics, and the MNOs themselves.
The MNO data show that call completion success rates (CCSRs) were broadly stable across all four networks, and had been so for the last couple of years.
However, the figures collected by RootMetric’s data reveal that there is still more work to be done. Across the UK, 97% of calls on the EE network were successfully connected, compared to 95.3% on O2, 94.2% on Three, and 92.6% on Vodafone.
In rural areas, the data shows that Vodafone connected only 79.9% of calls successfully, compared to 93.7% on the top-performing network.
RootMetrics' data was collected in late 2013 through sampling by individual testers placing calls from consumer handsets and then uses statistical analysis to show 95% confidence levels for each metric, while in contrast, the MNO data covers all calls made by consumers in areas with network coverage.
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Ofcom also surveyed a number of consumers and found that over half said they never, or hardly ever, had to contend with no signal or reception, compared to 30% who experienced such problems on a weekly basis at least.
The vast majority, 69%, said they never had a blocked call, and 65% said they never had a dropped call, but a fifth reported blocked and dropped calls at least weekly, a proportion that increased in rural areas.
Ofcom reported that it had agreed to work with all four networks to develop a common methodology for measuring successful call completion rates.
Vodafone contested the report’s findings, claiming that RootMetrics' statistics were long out of date. It pointed to the recent launch of its Rural Open Sure Signal programme, which is using femtocell technology to improve 3G coverage in rural communities.
EE said the figures reflected the major investment it had been making in its network capacity.