There are significant differences in the accuracy and reliability of online speed tests. Quite frankly, many online speed tests are a complete waste of time, results from which will bear little resemblance to your actual throughputs. Even straight speed tests can vary depending on the demand on your transmitter tower. You are not the only one using that tower…

Theoretical Speeds by Network Technology

To understand just how fast 4G is, we need to put the technology into perspective against the older mobile network technologies, namely 3G and 3G HSPA+. To do so we’ll look at the theoretical and real-world performance of 4G LTE, as well as looking 4G speeds on the UK’s mobile networks. When it comes to measuring mobile network speeds there are two situations which are of interest, theoretical and the real world.

Theoretical speeds are those which you can expect to obtain in a laboratory environment with perfect conditions, while real world speeds are those you can expect to get everyday using your phone on a real mobile network. To benchmark network speeds, we are interested in download and upload speeds. Download speeds are the rate at which mobile data is transferred from the internet to your phone or mobile device e.g. downloading a video. While upload speeds are the rate that mobile data is transferred from your phone or mobile device to the internet e.g. uploading a photo to Facebook.

Theoretical Maximum Network Speeds

Network Type Download Speed (Mbps) Upload Speed (Mbps)
3G 7.2 2
3G HSPA+ 42 22
4G LTE 150 50
4G LTE-Advanced 300 150


Typical Real World Network Speeds

Network Type Download Speed (Mbps) Upload Speed (Mbps)
3G 3 0.4
3G HSPA+ 6 3
4G LTE 20 10
4G LTE-Advanced 42 25


It is important to consider the conditions in which you should run an online test. When you run a speed test, there are a number of issues that could cause the online speed test to measure a lower speed than the actual throughput of your connection, so you should take the following precautions:

  • Ensure that there are no other programs or applications running in the background when running an online speed test. Another program running on your device at the same time (for example, a software download) could be using your Internet connection while you are trying to run a speed test. So, close any programs that may be running on your device, including anti-virus software, peer-to-peer clients, online storage applications and automatic updates.
  • Ensure that no other devices on your network are using the broadband connection (for example, a mobile phone or tablet in another room). Many people now have a number of devices connected to their broadband connection, including set-top boxes, games consoles, laptops, tablets and mobile phones. Any of these could be using your broadband connection at the same time.
  • Beware that the speed test server may be highly loaded. Particularly at peak times, the servers used to provide online speed tests could be overloaded. Try to run speed tests at different times of the day, and on different days, and note the best results. Generally, the highest results will be the most accurate.
  • Directly connect your device to your router by Ethernet cable. Avoid running an online speed test if connected to your router by WiFi (or a powerline adapter). Your WiFi network could be the weak link in your broadband chain so you’ll end up measuring the speed of your WiFi connection rather than your broadband connection.
Furthermore, WiFi interference issues can often cause rapid fluctuations in online speed test results. If you have no alternative than to use WiFi (for example, you are using a tablet), then ensure that your WiFi is optimised and be located next to your WiFi router.