Diagnose Wi-Fi problems and optimise your network
GET THE TOOLS YOU NEED TO MAKE THE MOST OF YOUR WI-FI CAPABILITIES.
WHEN YOU’RE GOING about the business of optimising your Wi-Fi network, there are few tools more useful than a Wi-Fi scanner. These apps give you an overview of all the wireless access points in range of the device you’re running it on. You can use them as mobile sensors to detect gaps in and test the strength of your own Wi-Fi network; or you can use them to detect which channels your neighbours are running their networks on.
So what are the best Wi-Fi analysers for each platform? This month, we’ll take a look at our top picks, as well as walk through how you can use such an app to choose the best Wi-Fi channel for you.
TOP WI-FI ANALYSERS WINDOWS: NIRSOFT WIFI INFOVIEW
www.nirsoft.net/utils/wifi_information_ view.html We’ve actually bounced around when it comes to a favourite scanner for Windows. There are actually a number of them available, but some of our favourites (like inSSIDer and Riverbed Wi-Fi Inspector) have gone commercial and only have free trial versions now.
Which brings us to Nirsoft’s freeware WifiInfoView, a basic tool that doesn’t have the fancy graphs and visualisation of the aforementioned tools, but still gives you a useful overview of neighbouring networks and their signal power relative to the position of your Windows PC.
While we like the simplicity of WifiInfoView, if you want something a little more visual, you can try WiFi Analyzer for Windows 10 ( matthafner.com/wifianalyzer), a tool that looks very much like Wi-Fi Analyzer on Android. It’s available in the Microsoft Store.
Another worthwhile tool is the free version of Netspot ( www.netspotapp.com). The free version of Netspot provides the most comprehensive overview of local wireless networks that we’ve seen, including performance graphs of individual wireless networks. If you want the home survey and visualisation tools, however, you’ll have to fork out for the commercial version of Netspot.
MACOS: BUILT-IN
While Netspot is available for MacOS as well, you don’t actually have to install anything at all on a Mac to run a survey of local wireless networks. MacOS has that capability already. Just follow these steps:
Hold down the Option key and click on the Wi-Fi signal icon at the top of the screen. This brings up a special options menu. In that menu, select ‘Open Wireless Diagnostics’.
Go up to the menu at the top of the screen. Click on Window, then select Scan from the drop-down menu.
This will bring up a Window with all the networks detected by your Mac. It will even recommend the best channels for you to use in both the 2.4GHz and 5GHz bands (more on that a little later).
ANDROID: WIFI ANALYZER
Available on the Google Play Store If you’re a regular reader of this column, you’ll probably already be familiar with Wifi Analyzer from farproc, which can be downloaded from Google Play. A free and immensely useful app, Wifi Analyzer lets you quickly visualise all the Wi-Fi networks that
your Android device can detect. It displays them in a graph, showing how the networks overlap and the relative strength of each one. It can also provide a recommendation for which channel to use in the 2.4GHz band.
iOS: NONE AVAILABLE
While there are excellent tools available for Android, if you’re using an Apple phone that hasn’t been jailbroken, then you’re out of luck. iOS does not allow apps to scan Wi-Fi networks that they’re not attached to, which means that nothing like Android’s Wifi Analyzer is supported on the platform. Instead the the ‘WiFi Analyzer’ apps available only allow you to test the network to which you’re connected using a port scanner and internet speed tools.
Even on jailbroken phones, the options seem limited. Previously, apps like WiFiFoFum were available, but even that app seems to have now disappeared.
CHOOSING A CHANNEL
Now that you have a Wi-Fi network sniffer tool, you’re ready to use it to choose the best channels for your home network.
So what the heck are channels, anyway? The simple answer is that they’re like channels on a TV set. The radio bands used for Wi-Fi (the 2.4GHz and 5GHz bands) are broken up into segments, each 20MHz wide. So that they’re not fighting over the same airwaves, ideally, different Wi-Fi networks in the same physical space use different channels. For example, if you’re using channel 1, and your neighbour is using channel 6, then you’re not competing for airwaves. If you were both using channel 6, then each of you would be effectively halving your available bandwidth.
Pretty much every router and access point on the market today allows you to choose your channels — or to let the router automatically select a channel for you. To change your wireless channel, you’ll have to log in to your router’s admin console and find the wireless settings. There you can choose a channel, or to let the router choose for you.
Ideally, you want to set a channel that’s as far away as possible from what your neighbours are using. And this is where the Wi-Fi scanners from before come in — they tell you what channels your neighbours are using and help you steer clear.
In the 2.4GHz band, there are 13 channels available in Australia. Here’s the thing — even though the channels are 20MHz, they actually overlap. Channel 2 overlaps quite a lot with channels 1 and 3, for example, and a bit with channels 4, 5 and even 6. The only channels that don’t overlap with each other are 1, 6 and 11 — which is why these are commonly the ‘default’ channels for many routers.
To choose your 2.4GHz channel, take a look at what channels your neighbours are using in the Wi-Fi analysis tool. Try to pick a channel that nobody else is using and is as far away from any of the other channels as possible, so you can grab as much of your available bandwidth as possible.
The 5GHz band is a little more complicated. Technically, there are some 35 channels available for use in Australia, although most routers only allow you to choose from four to preserve international compatibility. The good thing about the 5GHz band is that there is more space between the channels, so that you don’t have to worry about overlap like you do in the 2.4GHz band. Just choose a channel that nobody else in your neighbourhood is using, and you should be good to go!
SO THAT THEY’RE NOT FIGHTING OVER THE SAME AIRWAVES, IDEALLY, DIFFERENT WI-FI NETWORKS IN THE SAME PHYSICAL SPACE USE DIFFERENT CHANNELS.