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A company that fitted mobile phone coverage trackers to council bin lorries across Caerphilly County Borough has published its findings.

Over an 18-month period, Streetwave completed two mobile coverage surveys, tracking live signal data from four national mobile networks – EE, O2, Three, and Vodafone.

The first survey was carried out in September 2024, while the second survey took place 18 months later in March 2026.  

All four national operators were measured simultaneously during each survey. 

Three saw the largest improvement, with essential coverage rising from 69% in 2024 to 90% in 2026.

Vodafone increased from 80% in 2024 to 97% in 2026, while EE improved its perfromance from 85% to 97% in that same time period.

However, O2 saw a decline, with its essential coverage decreasing from 85% to 73%.

Vodafone and Three’s merger, which happened last year, sees the networks share antennas and masts, meaning any infrastructure improvements benefit both networks at the same time. 

Streetwave’s data suggests that the merger has already benefited residents, as Vodafone and Three presented the largest essential coverage gains of any operator.  

Both surveys were commissioned by Caerphilly County Borough Council.

Residents and businesses can enter their address on Streetwave’s website to find out which network performs best in their area.

Download and Upload speeds

The surveys also looked at download and upload speeds per operator.

September 2024 download speeds (Mbp/s):

• EE – 26.28 
• Three – 21.93 
• Vodafone – 16.85 
• O2 – 11.17 

March 2026 download speeds (Mbp/s):

• EE – 18.59 
• Three – 26.49 
• Vodafone – 17.56 
• O2 – 9.76 

Both Vodafone and Three saw an increase in download speeds, while EE and O2 decreased.

However, upload speeds improved for all four operators in March 2026. 

September 2024 upload speeds (Mbp/s):

• EE – 5.42 
• Three – 4.28 
• Vodafone – 4.57 
• O2 – 4.24 

March 2026 upload speeds (Mbp/s): 

• EE – 9.29 
• Three – 7.04 
• Vodafone – 7.64 
• O2 – 5.33