Three & BT Mobile put head-to-head for London mobile data speed

BT Mobile (EE) network performance in LondonBT Mobile (EE) network performance in London

In this article we are writing up a real-world exercise which directly compares data speeds achieved in London on Three and BT Mobile.  The aim of this test is to show the types of performance that everyday users can expect on each network, whith hard numbers to back up the claims.  More details on the frequencies that each network operates on can be found here.

Key Points to Note

  • BT Mobile provided an average download speed of 21.68Mbps;  Three provided an average download speed of 12.75Mbps
  • BT Mobile provided an average upload speed of 10.99Mbps;  Three provided an average upload speed of 6.35Mbps
  • Both networks provide excellent 4G coverage across London.  There was only one instance of falling back to a 3G (H+) network, which was on Three when a sample was taken at the Barnes Wetland Centre
  • There was only one instance of a test failing completely, this was by Three on Oxford Street the week before Christmas
  • When on 4G Three always used the 1800MHz frequency band;  BT Mobile predominantly used 1800MHz which a few instances of 2600MHz and no instances of 800MHz
  • BT Mobile runs on EE‘s network, Three uses its own
  • BT could go faster if we paid for improved speed, but the point of this test was to use standard plans

Methodology & Test Hardware

The phone used for testing was a dual sim Samsung Galaxy S7 running Android 6.  As this was a dual SIM phone there can be no bias between the two networks in terms of phone and software – it was the same, single device used.  The phone supports all the frequencies of each network.

Prior to any test, the phone was put into flight safe mode then taken out of it again.  This was to ensure that the phone searched for the best available cell tower at that point in time.

Locations were chosen as part of normal daily routines across the period of a few weeks running from mid December 2016 to early January 2017.  We used the Speedtest Android app on each network to run a speed test, and logged the results.

Mobile Plans

Both the Three and BT Mobile plans were standard pay monthly plans.  It would seem that the Three sim card had no upper limit in terms of speed, whereas the BT Mobile plan did.  Looking at the data it would seem that this is around the 30Mbps mark.  It is possible to pay for increased performance on BT Mobile, which we expect would have increased the win by BT Mobile even further, however during this test we wanted to assess the performance of standard plans.

You can read more about each network at the following links:

Three Mobile

BT Mobile (running on the EE network)


It’s clear that, on average BT Mobile running on the EE network provides better speeds than Three.  The average download speed on BT Mobile was 21.68Mbps vs 12.75Mbps on Three; similarly on upload BT Mobile’s average was 10.99Mbps vs Three’s 6.35Mbps.

Three did take the top spot for fastest outright speed in a single test (even if this was because we were not paying extra for BT Mobile’s faster speeds).  Three’s top speed was 59.18Mbps vs BT Mobile’s top speed of 31.92Mbps.

It is interesting to note the fluctuations in Three’s performance, which can be seen clearly on the charts below.  Whilst there are some strong peaks in the download speeds, there are a lot of very low speeds (although enough to check email, run WhatsApp etc).  Contrast this with BT Mobile running on EE and there isn’t this spikiness to the data – it would appear that it is also the more consistent network.

Three network performance in London

Three network performance in London


BT Mobile (EE) network performance in London

BT Mobile (EE) network performance in London

The raw data is as follows:

Location Three Download Speed (Mbps) Three Upload Speed (Mbps) BT Mobile Download Speed (Mbps) BT Mobile Upload Speed (Mbps) Indoors or Outdoors
Colliers Wood 2.5 0.3 29.69 15.51 in
Tooting Broadway 16.51 15.68 19.18 15.3 in
Kingston Station 0.35 0.75 30.13 17.33 out
Wimbledon Village 59.18 7.41 30.28 15.08 in
Wimbledon 0.56 1.49 30.52 16.81 out
Tooting 1.5 0.01 14.2 2.05 in
Canary Wharf 14.48 9.5 31.92 15.7 in
Wapping 32 11.11 27.89 3.24 out
Kennington 5.38 1.4 21.66 4.17 out
Morden 16.29 5.74 12.65 4.97 out
Tooting Station Platform 27.96 7.84 15.7 4.62 out
Wimbledon Station Platform 29.45 12.05 29.08 16.23 out
Vauxhall 1.2 5.05 0.89 14.12 out
Piccadilly/Green Park 0.66 1.66 15.24 0.12 out
Oxford Circus 0 0 4.59 1.57 out
Bond Street 0.05 0.04 1.14 5.7 out
Liverpool Street 0.33 0.92 7.67 7.39 out
Wimbledon 40.5 6.72 30.53 17.12 in
Streatham 21.16 9.66 19.63 14.68 in
Colliers Wood 16.44 8.06 16.68 9.37 in
Lambeth 12.78 18 30.57 15.38 in
Elephant & Castle 19.33 9.44 29.51 2.87 out
Brixton 22.82 18.72 32.2 14.88 in
Tooting Common 10.69 4.83 15.75 4.6 out
Balham 4.01 0.19 17.68 15.65 in
Covent Garden 1.48 6.19 31.29 15.85 out
Seven Dials 5.04 13.51 29.64 10.12 out
Charing Cross Road 3.49 6.49 23.67 7.42 out
Barnes Wetland Centre 3.61 1.4 29.24 30.9 out

What does this mean for users?

If you are looking for the most solid data network we’d recommend choosing EE or an operator such as BT Mobile that runs on top of it.  However, it’s also worth noting that even with some of the slower speeds seen on the Three network the throughput would, in most cases, still be sufficient for basic usage and users may find Three’s commercial packages appealing as these can include unlimited data plans and free roaming.

Using this data

You are welcome to reference the results of this article and even use the data.  All we ask in return is that the source is referenced and a weblink to this page is included in your online publications.

About the Author

James Harley
James lives in London and is a keen author in the consumer telecommunications space. He always has a keen eye on the latest news, offers and deals available to broadband users.

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