RootMetrics has published its Mobile Network Performance Review for the second half of 2014, once again placing EE as the best in the UK. However with Three not far behind as second, followed by O2 and finally Vodafone, the testing specialist claimed all four operators are doing well.

EE came first in five out of six categories of the network test, tying with Three on reliability. RootMetrics said the the results reveal all four networks are getting faster, but EE clearly distant itself from the others on speed. Naturally as the other operators continue their 4G rollouts, EE’s advantage in this area has eroded.

According to RootMetrics, Three’s best attribute is reliability as it shared the glory on this test both in the first and second half 2014 reports. In this latest review, Three has managed to climb from the worst performer in the call category to second, tying with O2. This meant Three came second in all six categories.

“An increase of this magnitude is rare to see, and Three’s jump in the call standings is yet more evidence that the network could become a serious competitor to EE’s lead,” RootMetrics said in the report.

“Three’s second place finish in network speed at the UK level is particularly noteworthy: Three does not have the same breadth of 4G footprint that the other networks have… Three’s speeds trailed those of EE by a wide margin, but its consistency not only in urban areas but also in rural spaces helped it outperform O2 and Vodafone, both of which were much slower outside the larger metro areas.”

Despite performing worst in the mobile internet category, O2 managed to overtake Vodafone overall. Vodafone’s lowest score came in the call performance category but tied with O2 in text. However, according to RootMetrics Vodafone’s performance has improved since the previous round of testing, beating O2 to the third place in mobile internet and speed.

“All the networks performed well in our text testing, with extremely small scoring variations between the top and the bottom,” the testing firm said. “Call performance also showed a narrower difference in scoring variation than what we saw in the other categories. As 4G rollouts continue, we expect the variation in speed, mobile internet, and overall scoring to likewise narrow.”

RootMetrics said the review is based on testing network performance across a 24,000 mile radius across roadways, big cities, small towns and rural areas across the UK. The firm claimed to have collected over a million samples while testing performance during driving, stationary outdoors and at more than 1200 locations.