Ofcom publishes research on mobile phone call service quality

12 August 2014

Ofcom has today published research on mobile phone call quality provided by network operators.

Improving mobile quality of service for consumers is a priority area for Ofcom. Today’s research is part of a plan to help support initiatives to improve mobile coverage in the UK, and provide consumers with quality information on mobile reception.

This information is important in helping consumers choose a mobile service that suits their needs. It also helps promote competition between mobile operators on service quality, to benefit consumers. Ofcom will continue to monitor and report on how service quality develops over time.

The report includes research on mobile phone call quality from the consumers’ perspective on mobile handsets; data supplied by EE, O2, Three and Vodafone on the performance of their networks; and consumer research on satisfaction with mobile networks.

Ofcom’s research found that while overall levels of consumer satisfaction with mobile networks are high (76%), this varies by location. Some 78% of people in urban areas were satisfied with their mobile network, compared to 67% in rural parts of the UK and 70% in remote areas.

Independent research findings

Ofcom used data from RootMetrics, a company that measures network performance on mobile handsets, to better understand consumers’ experience of making phone calls on EE, O2, Three and Vodafone networks.

The data shows the proportion of UK mobile phone calls that are connected successfully.

According to RootMetrics data, 97.0% of calls on the EE network were successfully connected, 95.3% on O2, 94.5% on Three and 92.6% on Vodafone during the second half of 2013.

The data shows that the proportion of calls connected successfully varied by provider across the UK, with significant differences in urban and rural areas.

UK data on proportion of 2G/3G calls completed successfully (RootMetrics)

UK data on proportion of 2G/3G calls completed successfully (RootMetrics)

Source: RootMetrics data for second half 2013, brackets on chart denote confidence range of data.

Network operators’ data

Aggregated data on ‘blocked’ and ‘dropped’ calls was also collected from the four mobile network operators.

Blocked calls happen when the user is an area of coverage but cannot make a call; this can be because of heavy demand on the mobile network. Dropped calls occur when a call is connected but then terminates unexpectedly. This can happen when a user moves into an area with poor or no mobile signal.

The operators’ data measures the proportion of completed calls, but excludes call attempts when customers are outside of network coverage, so differs from RootMetrics. This, in part, is likely to explain why the call failure rates reported by RootMetrics are higher than those in the operator’s data.

While each operator’s data is not directly comparable due to differences in measurement methodologies, it shows that about two in every 100 call attempts were unsuccessful (the range of successful calls a month was from 97.9% to 98.6%). There has not been a significant change in the proportion of calls successfully connected over time, with some networks showing improvements.

Consumer research

To better understand mobile reception problems, Ofcom asked consumers about their experiences of mobile reception.

More than half (55%) of people surveyed said they never or hardly ever had to put up with no mobile signal or reception, while nearly a third (30%) said they suffered such problems at least every week.

The majority of people said they never or hardly ever had a blocked call (69%) or dropped call (65%). However, a fifth of people said they experienced blocked calls (20%) and dropped calls (22%) at least once a week, and this increases in rural areas.

Next steps

Ofcom is making progress on its plan to help improve mobile coverage in the UK and provide consumers with reliable information on mobile reception.

EE, O2, Three and Vodafone have agreed to work with Ofcom to develop a common methodology for measuring the rates of calls successfully completed on their networks.

All four mobile providers are now meeting the 90% coverage obligations for 3G mobile, while mobile operators have indicated they intend to match O2’s 98% coverage obligation for 4G mobile. This will extend mobile broadband coverage into many areas still underserved by 3G.

Later this year, Ofcom will be publishing research comparing 3G and 4G mobile broadband speeds, following detailed testing across five UK cities. This will help consumers choose a service that suits them and encourages providers to improve performance.

Ofcom is working with Government on its £150m mobile infrastructure project, which is funding mobile phone masts in uncovered areas. Ofcom is also supporting the Department for Transport and Network Rail on improving mobile services on railways and welcomes recent proposals to invest £53m to improve Wi-Fi access on trains.

Ofcom’s report, Consumer experiences of mobile phone calls, is published here.



  1. Ofcom plans to use data for each local authority, similar to today’s research, in its 2014 Infrastructure report on the state of the UK’s communications infrastructure. Ofcom also offers a guide for consumers on maximising coverage.
  2. Ofcom’s 4G auction was designed in such a way that one licence - acquired by O2 - has to roll out 4G to cover at least 98% of the UK population (when indoors) by 2017 at the latest. This results in more than 99% coverage for 4G when outdoors. Other UK mobile operators have indicated they intend to match the 98% coverage.
  3. Ofcom’s UK Mobile Services Map 2013 provides information on the level of outdoor mobile coverage in the UK by administrative authority.
  4. Ofcom is the independent regulator and competition authority for the UK communications industries, with responsibilities across television, radio, telecommunications, wireless communications and postal services.
  5. For further information about Ofcom please visit: www.ofcom.org.uk. Ofcom’s news releases can be found at: http://media.ofcom.org.uk/