For the past few days I've been having some difficulty with my Linksys WRT54G wireless router. Every hour or so, my ThinkPad has lost its connection with the access point. This has been particularly frustrating this morning because I'm on call today, and have been trying to get work done since I was called at 5:30 to solve a problem with the scheduling system at work. I have to be able to connect to the IBM network to get any work done.
Well, I discovered what was causing the problem. I ran NetStumbler displayed a list of the WiFi devices within range of my computer. I quickly saw that another device in the neighborhood was using the same channel as my AP.
I selected channel 6 a long time ago because at the time no one else was using it. Now, there's another Linksys router out there (and very close, judging from the signal strength) that's also set to channel 6. This access point must have been installed recently, because I haven't seen it before, and the connection problems only begane a few days ago. Interference from the other access point (trying to communicate on the same frequency as mine) was surely the cause of my network troubles.
I connected to the web-based administration page of my router and select channel 14, because no other device within range was using any channel higher than 11. I then rebooted the AP to apply the change. To my surprise, my AP did not appear in the list of available networks when I refreshed the list. I waited a few minutes, thinking that it might still be rebooting. I refreshed the again, and still, my WRT54G did not appear. Uh oh.
After a few moments' puzzlement, I recalled that channels above a 11 are restricted in some countries (like the U.S. and Japan). I did a bit of digging through device preference windows, and eventually found the right option in the Advanced tab of the 802.11 a/b/g device properties window. I set Extended Channel Mode to Enable, applied the change to the device, and refreshed the list of networks again. Eureka — my AP appeared in the list.
I've been running happily on channel 14 for the past hour and a half, with narry a network problem to report. So far, so good.
Note1: I have hacked my Linksys WRT54G with custom firmware called Freeman. It makes the device much more capable than one with stock firmware.
Note2: If you're planning on getting Linksys wireless router and using custom firmware, be sure to get the WRT54GL. This model (with the L at the end) is the one that has sufficient memory to hold custom firmware.