Improve Wifi with scanner software

One downside of wireless networking is that all these cordless connections rely on a limited amount of space in the radio spectrum. While Wifi routers have the ability to use different frequencies within this radio space, there is no guarantee that your neighbours won’t also have their equipment tuned to the same channel. Install scanning software to detect the quietest frequencies, using a free tool called InSSIDer. InSSIDer is compatible with both 32- and 64-bit versions of Windows XP, Vista and 7. To download and install it, first launch a web browser and head to www.computeractive.co.uk/1914167. When our website appears, click the red Download now button. If the File Download Security Warning dialogue box appears, click Save and choose a location for the downloaded file such as the Windows Desktop. Firefox users should select Save File to save the download to Firefox’s default download folder. Now double-click the file you have just downloaded.

Ignore any security warnings from Windows (by clicking Run) and follow the prompts of the InSSIDer setup wizard, accepting all the defaults and clicking Next at each stage to move on. At the final screen click Close. InSSIDer does not launch automatically, so click Start and point to All Programs followed by the Metageek program group: now click InSSIDer to launch the tool.

Before it can scan for Wifi equipment, InSSIDer needs to know which wireless network adapter to use and its frequency. This could be a wireless network card inside a PC or a USB adapter for a laptop. Select the wireless network adapter from the dropdown list at the top of the application window. Next, click the relevant radio button to indicate its frequency. If you are not sure of either then refer to the manufacturer’s instructions – most Wifi equipment uses the 2.4GHz band.

Click the Start Scanning button and InSSIDer will get to work. Soon enough, a list of nearby wireless access points will be displayed as a list at the top. There are further details under various headings, including the network name (SSID), encryption type (Security) and, for our purposes, the all-important frequency (Channel). Below this are two graphs. The left-hand chart shows the various networks’ signal strengths over time, colour-coded to match the aforementioned list. The one on the right, meanwhile, shows the Wifi channel numbers used by each piece of equipment. For technical reasons, a Wifi router will send and receive data over several channels, so don’t be surprised to see overlapping here (as in our screenshot). The graph windows can be resized by dragging and dropping the divider bars.

It is worth watching the graphs for a good few minutes to get a clear picture of spectrum use. Here, for example, we can see that the Wifi network called White Whale is particularly strong. Checking its channel number in the list above we can see that it is set to ‘9’ – so it would be sensible to avoid using this channel for our own Wifi equipment, to minimise bandwidth clashes. Do note, though, that the time graph on the left suggests this is a blip – so perhaps the White Whale network isn’t such a problem after all. Incidentally, the list of wireless access points can be sorted by clicking any of the headings: sort by Channel, for instance, to see which channels are the busiest.

Use this information to determine the quietest channel number in your locality. Then log in to your router and change the channel number accordingly. Obviously, every router is different, so if you don’t know how to do this you will need to refer to the manufacturer’s instructions. Here, for example, we have logged into our Linksys router by typing 192.168.2.1 into a web browser’s Address bar and pressing Enter. The channel setting is available under the Wireless tab.