Inside InSSIDer: Your Wi-Fi Connectivity Analyzer

You may often wonder what governs the range and strength of your Wi-Fi router’s performance. There’s a lot of talk among industry insiders about whether adjusting a router’s antennae has any effect. Rather than get bogged down in that debate, I want to introduce you to a handy tool you can use to monitor your wireless router’s performance and aid troubleshooting when your connection seems to underperform. It’s a freeware program called inSSIDer.

At first glance, inSSIDer might seem like little more than a fancy version of Windows’ built-in wireless network selection tool — the pop-up menu that lists available connections and their signal strengths. Likewise, InSSIDer has a real-time graph of the strength of every wireless signal you could connect to. So what?

For starters, InSSIDer tends to find wireless access points that Windows omits or combines into a single, simplified header. That’s partly because InSSIDer lists all available wireless networking connections by the connecting device’s unique identifier, or MAC address. As a result, you’ll often find many more networks than those appearing in Windows’ list of potential connections.

Why is this useful information? Certainly not to encourage you to connect to unknown, open wireless networks — I explained in a previous post why latching onto unknown networks is a bad idea. Rather, by seeing the strength and scope of other wireless networks in your immediate vicinity, you can alter the settings of your own wireless network to reduce interference among all the competing signals.

To do this, let InSSIDer scan for a little while, then click over to the app’s “2.4 Ghz Channels” screen. This assumes you’re running a 2.4-GHz wireless signal instead of a dual-band setup such as D-Link’s Xtreme N Dual Band Gigabit Router. Check out which channels are being bombarded with signals and the amplitude of the signals themselves, then hop on over to your router’s settings to switch to a channel setting that’s not quite as populated with activity.

As simple as that, you’ve just used InSSIDer to make a beneficial change to your wireless setup. To assess the improvement, you can use InSSIDer to automatically measure your network’s signal strength from a variety of locations around your home. If changing the channel didn’t result in much improvement, try another.

InSSIDer uses a real-time graph to display the measured signal strength of every wireless signal that your laptop can pick up. In this case, I've used it to show the differences between my D-Link router's antennae pointing toward my laptop, directly up into the air, and away from my laptop.

InSSIDer creates real-time graphs of the signal strength of available wireless networks. You can narrow the program's analysis to signals passing through either the 2.4GHz or 5GHz bands.

Subscribe to the Best of PCWorld Newsletter