VODAFONE have hit out against a RootMetrics report which placed the network last in terms of speeds and reliability.
RootMetrics is biased towards EE, which came out top, and uses outdated data, Vodafone said last week.
EE have now reacted with outrage to Vodafone's assertion that the test was biased against them.
"Independent tests are, by their very nature, independent," an EE spokesperson said.
In their first ever national network test, they've tested London before, RootMetrics found Vodafone to be the worst of the four major networks, failing miserably in just about every area.
The network did particularly badly when it came to mobile internet, as shown on the right.
The RootMetrics score for mobile internet is made up of their research into the reliability and speed of file, webpage and email up and downloading.
In other tests, like the speed of sending and receiving text messages, shown below, the gap between Vodafone and the other providers is less pronounced, though, as in all of RootMetric's tests, they are still last.
Unsurprisingly, Vodafone were less than happy with these results.
More surprisingly, the provider expressed their displeasure in a scathing attack on both RootMetrics and EE. The network said that the report shouldn't be taken seriously by consumers because it was "inconsistent" and biased towards EE.
This week, EE strongly refuted those claims saying that the tests are independent and, as suggested by Vodafone, they played no part in the report being commissioned.
However, EE have confirmed that they do indeed buy data from RootMetrics, something that neither Vodafone, O2 nor Three do.
RootMetrics' boss Bill Moore said that though some operators might feel uncomfortable with the findings the company stands by its results.
So here's the big question: does Vodafone's claim that RootMetrics are biased towards EE because of their commercial relationship hold any water?
The data EE buy from RootMetrics allows them to use their report findings, the ones that put them top or tied for top in every category, in their advertising.
To a suspicious mind, that might suggest RootMetrics have an incentive to give EE positive results, to keep them buying the rights to use the information.
Alternatively, and some would say more plausibly, EE might be more inclined to buy the right to use findings because they show them in a positive light.
It's also worth noting that EE also buy raw data from RootMetrics that helps them to establish areas with poor coverage and don't have an exclusive relationship with the company. All four operators are able to purchase the results of the tests should they wish to, while EE buy data from a number of organisations, not just RootMetrics.
On the other hand, it is true the way RootMetrics was likely to favour EE in terms of the overall score.
The scores are determined by 45% call, 45% data and 10% text. However, the technologies aren't split, meaning that the network with the best 4G is always going to win.
At the time the data was collected - the second half of 2013 - EE had enjoyed several months as the UK's only 4G provider, while Vodafone had only just started rolling out their 4G service.
Again, however, we can only go so far with this: remember that Vodafone lost out in all the categories not just the overall score and, in terms of actual methodology, RootMetrics seem spot on.
RootMetrics use the top selling handset on each network to establish reliability, speed, mobile internet and call reliability throughout the UK (their testers drove 23,000 miles, in all, for this latest national report).
Most other mobile broadband speed tests we've seen use crowdsourced data.
For example, Ookla Net Index research released in February using Speedtest.net results, which are more 'real' but less reliably sourced than RootMetrics', was more favourable to Vodafone.
Again, however, EE are coming first (even if they're also coming last).
OpenSignal also uses this method and a spokesperson has admitted that when they combine 2G, 3G and LTE, EE does come out on top.
Vodafone may be able to take comfort in some other research released this week, however.
Ofcom's quarterly telecoms complaints data shows that Orange and T-Mobile customers are the most likely to have cause for complaint.
SOURCE: Ofcom telecoms complaints report. Accessed 27/03/14.
The bulk of those complaints are likely to be about billing and other customer service issues, rather than mobile speeds or other performance problems.
More to the point, even here, Vodafone aren't the outright winners.
Both Three and O2 had fewer complaints in the three months to December.
As if Vodafone hadn't had enough PR disasters in recent weeks, BT confirmed that they have ditched the network as their MVNO provider this week.
And, just to rub salt in the wound, that replacement is none other than EE.
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