Improve Wireless LAN Performance

Recently I noticed poor WiFi performance in my home wireless LAN and was wondering what the reason might be.

After some research I found out that there are some other WLAN access points in my neighborhood causing interferences which decreased my WLAN’s bandwidth. AP Grapher is a nice, simple and free program that I used on my Mac to find access points in my area. Its “AP Scanner” scans for access points and shows their signal strength and channel. In case you’re using Windows, try NetStumbler – it should do pretty much the same.

Wireless LANs can be configured to use channels 1-13. I saw a nice graph on another blog showing ranges of these channels. Basically the important thing to know is that channels have overlapping ranges. In order to have full bandwidth you need to have as much distance to other channels as possible – best is 5 channels distance, because this way there’s no interference at all. E.g., channels 1 and 6 don’t overlap at all. Channels 1 and 5 overlap a little bit, etc.

Well, when scanning my area, I got the following results:

  • My own WLAN: channel 1, 100% strength
  • Other WLAN A: channel 1, 81% strength
  • Other WLAN B: channel 1, 15% strength
  • Other WLAN C: channel 6, 90% strength
  • Other WLAN D: channel 11, 8% strength

Obviously WLAN A and B completely interfered with my network as they were using the same channel.

I found that the best solution for my situation was to use channel 13 from now on. It interferes a little with WLAN D, however WLAN ┬áD luckily isn’t strong, so I guess it interferes even less.

After switching to channel 13 my WLAN performance increased appreciably – mission accomplished.

Comments are closed.