Wifi networks are quite commonplace nowadays, with virtually all modem/routers coming equipped with Wifi capability out of the box. Whether it be in homes, workplaces, or even cafes, there’s generally a Wifi network nearby which allows you to connect your device to the internet without having to physically hook up a network cable. In theory, the connection speed through Wifi should be fast enough so that you don’t notice any difference between Wifi and network cable speeds, however in practice many people experience noticeable speed issues with Wifi. There could be a number of factors which could explain slow Wifi speeds, but the one (and a major one it is) we will focus on today is choosing the right channel.
On the user end, the channel you use is completely invisible; you can’t specify a channel to connect to on your iPhone or Android, for example. The channel selection is done on the modem/router side, and needs to be configured through the device’s admin interface (generally a web interface accessible through any web browser with admin credentials). Channel selection plays a part due to the prevalence of Wifi networks in urban areas; simply put, if two nearby Wifi networks are using the same channel, they can potentially interfere with each other causing speed issues for users connecting to either network. So if your modem/router is configured to use, say, Channel 3, and your neighbour’s is as well, then you may experience slower Wifi speeds. Even if they’re on Channel 2 or 4, there is still an overlap and you still may experience speed issues.
How to get around this? We will be assuming that you are using 2.4GHz Wifi as it is the most common despite the release of 5GHz in recent years. The first step you should take is making sure that your modem/router is configured to use Channel 1, 6 or 11. This is because each of the 14 Channels operates on a specific frequency range somewhere in between 2400MHz and 2500 MHz, and each Channel occupies 20MHz. Do the maths and you’ll see that there will be a lot of overlap (14 x 20MHz = 2800 MHz spread across a 100MHz range), but fortunately Channels 1, 6 and 11 are far enough apart from each other that there is no overlap.
If you still have issues, there are a number of free software and even smartphone app options for analysing Wifi channel usage in your vicinity and choosing the best one for you to use. If you have a Mac, Mac OS X actually comes with a Wifi channel analysis tool. There are many free options for Windows users too, such as WifiInfoView by Nirsoft and Acrylic Wifi by Tarlogic Security. The next option is buying a new modem/router and using 5GHz, which will most likely resolve any channel issues you are having because it features 23 non-overlapping channels!