Find out what WiFi channels your neighbors use and avoid interference

As you may have known, it is recommended to choose a channel among 1, 6, 11 for your wireless network. You can also choose other channels and actually some people do. But that is not doing good to your and other wireless networks. Why 1, 6, 11 are recommended? Because these channels do not intervene with each other.

The air is getting more and more crowded. Chances are some of your neighbors have also installed wireless networks. You would want to find out which ones they use and choose a less intervened one for yours. In Windows, you can use this command to find out the wireless networks around you:

        netsh wlan show networks mode=bssid

We only care about the strength of the signals and their channels. If the list is very long, we can filter it:

        netsh wlan show networks mode=bssid | findstr "SSID Signal Channel"

If in your neighborhood, either channel 1 or 11 are not used, you are lucky. These two have the less interference from the other channels. It is very likely all the recommended 1, 6, 11 channels are used by some neighbors. Should we select another channel? It may not help because anyone of the rest can still get interference from these recommended channels. There is no ideal place to hide. It is better to pick one from the recommended three which has the weakest and least signals.

 (The similar command in Linux is $sudo iwlist scan.)