Troubleshooting a wireless network

Unlike my previous post about "fixing" my wireless network by going wired, I actually had to do some wireless network troubleshooting over the weekend, so I thought I would share the experience.

Pam was having trouble with wireless dropouts and poor coverage. When I initially setup her wireless network, she didn't have any of those problems. Wireless routers, are typically all-or-nothing, i.e. they either work or they don't, so the fact that her wifi worked some of the time indicated that something else was interfering with her wireless network, rather than the wireless router going bad.

Wifi interference can be caused by any number of other electronic devices that use the same frequency in the 2.4 Ghz range. Fortunately, wireless hardware manufacturers included a user-selectable channel setting specifically designed to combat interference. Googling wifi interference returns a multitude of search results.

Pam's router, a Netgear FM114P, was still using the default channel setting of "6". I had heard of fancy wireless scanning gear that will scan a location, and identify frequencies already in use, but not having such gear my disposal, I knew it would be an exercise in trial and error. I dropped the channel setting to "4", allowed the router to reboot, and watched in amazement as the entire wireless router completely disappeared. My laptop didn't even pick up the SSID! I had probably stumbled upon the sweet spot of the interference, where it peaked the most. So, I decided to try the other direction. I selected channel 11, from a computer with a wired connection since wireless was effectively neutralized, and rebooted the router. This time, the results were vastly different, in a good way. My laptop automatically picked up the defined SSID, and before I could even get to the keyboard, it had negotiated an IP address. I walked over to Pam's laptop in the next room, and it had done the same. I carried my laptop to the far end of their house, and had Pam do the same. No dropouts, and a good strong 90+ signal.

Adjusting the wireless router channel also allowed them to finally get their Nintendo Wii online. I suppose I could have used NetStumbler and tried EVERY channel to see which provided the best signal, but I'll save that for a later date. Knowing that the wifi "bubble" lives in an ever-changing world, all it will take is one neighbor to buy a new cordless phone or baby monitor, and I'll be back to re-tweak the settings.