When it comes to assessing the data transfer performance of a mobile, cellular or wireless network on our Android devices, there are three main metrics that most speed benchmarking applications measure. Most providers concentrate on the download speed, that is how quickly data can be pulled down into your device from the network it is connected to. A high download speed makes it possible to stream high definition videos, download large files or applications quickly, or quickly load web pages. As one might expect from the name, the upload speed is how quickly the device can push data from it into the wider network. A higher speed upload link is good news is you like to create content on your device to share with the world, such as videos and pictures. And the latency is, in simple terms, the speed at which the network starts to respond. Latency is measured in milliseconds and determines the time it takes for a given source to send a packet of data and for it to be received by the host device.
There are a number of different network speeds used for 2G, 3G and LTE networks and each promises high speed downloads, but comparatively little has been made of the difference in latency figures between these networks. And yes, 2G networks have high latency, sometimes in the region of 800 to 1,000 ms (in other words, close to a full second before the packet is received by your device). 3G networks show significantly lower latency figures compared with 2G GPRS and EDGE networks and earlier in the year, UK telecommunications regulator reported that the average latency figure for the British 3G cellular data networks was 63.5 ms. However, LTE networks show an even faster latency score, with the British networks averaging 53.1 ms.
Lower latency figures are important for a couple of reasons. The first is that this is how quickly your Internet connection responds when you tell it to do something else. It is unlikely that customers will be able to tell a difference between a 63.5 ms and a 53.1 ms latency when browsing a web site, but there it becomes more relevant is when using services such as online gaming and video chatting. This fact is not lost on the US carriers, where they explain to customers that a lower latency is a good thing. Back in 2010 when Verizon Wireless started rolling out its LTE network, it claimed that the LTE network had half the latency of their 3G network. There are technical reasons why this gap has narrowed (as a cellular network becomes busier, so latency can dramatically increase, and as more customers migrate to LTE this frees up the 3G capacity and so reduces latency).
At the bottom of the article you can see two tables showing the North American carriers' latency figures, thanks to the FierceWireless website and their technical partners, OpenSignal. There are a couple of observations to make and the first is that the LTE networks are on the whole almost twice as responsive as the older generation 3G (UMTS, HSPA, HSPA+) networks. The most responsive network as measured by latency is Sprint, followed by T-Mobile US with Verizon snapping at their heels. Given that network latency goes up as the network reach capacity, it should be no surprise that the smaller (and less busy) carriers have a more responsive network. The data is collected by OpenSignal using as panel of more than one million consumer devices so as to obtain as accurate a picture as possible. The latency test uses three ICMP pings to google.com and takes te arithmetic mean.