Wireless Tips & Tricks: Troubleshooting Dropouts

Wireless Tips & Tricks: Troubleshooting Dropouts


I frequently lose my Wi-Fi signal, usually right when I really need to get online. Then it comes back a few seconds, a minute or even an hour later. What gives?

If you have a home Wi-Fi router, chances are you experience periodic signal dropouts with more or less regularity. There are several reasons for this annoying problem, some of which you can control, and some of which you can't, but here are some tips for dealing with the problem.

First, be sure you (and your close neighbors!) don't have 2.4GHz cordless phones or baby monitors in the house. This is the same frequency that Wi-Fi uses, and if someone is talking on the cordless phone, it will likely cause severe interference with your network. Cordless phones are available in several other frequencies, so just switch, or better yet, get rid of your landline altogether and switch your home number to your cell phone.

Second, check if the dropouts seem to coincide with the use of your microwave oven, or any Bluetooth devices, such as wireless mice, keyboards, and printers. These devices also use the same frequency as Wi-Fi, and can cause interference. Place your Wi-Fi router as far from them as possible.

Finally, check to be sure that your neighbors don't have competing Wi-Fi networks on the same or a nearby channel. In the U.S., Wi-Fi channels range from 1 to 11, each focusing on slightly different frequencies in the 2.4GHz radio band. But you can't simply set your router to channel 4 if your neighbor uses 3 and expect that to fix things. Wi-Fi channels overlap, just like those on your FM dial. That's why you see spacing between radio stations, and the bigger the station, the more space it takes up due to a stronger signal that spills over into neighboring airwaves.

With most Wi-Fi routers, you need a spacing of 5 channels or so to get rid of interference. So channels 1, 6, and 11 could be used by three different access points in the same area without much trouble. Super-G, MIMO and draft-802.11n routers, however, bond two channels together to achieve their faster throughput, and their signals spill over into virtually the entire 1-to-11 channel band. There's really only room for one regular Wi-Fi channel in the same area as a channel-bonding router, so you'll need to space them as far apart as possible.

To see what channels are being used, look at the list of available access points given by your Wi-Fi card software. You can also use a Wi-Fi sniffer program to detect closed networks that don't broadcast their SSID, such as Kismet for Linux, and KisMac for Mac OS X. Once you have a list of surrounding access points and channels used, coordinate with your neighbors to select non-interfering channels for your routers.

If some neighbors won't budge, you can probably blast them out with the stronger signals from a MIMO or draft-802.11n router with intelligent antenna technology, such as the 240Mbps Linksys SRX400 or the 270Mbps Netgear RangeMax Next. They have much greater range and performance than standard routers. it's an expensive solution, but a pretty sure one.