The 'auto channel' feature on routers - the cause of wireless connection problems

brophs

Hi all,

Just thought I'd post a quick solution I found to some ongoing wireless connectivity problems I'd been having. Perhaps it will help someone.

I'm with Eircom and had the Netopia 2247 which started to fail. Eircom sent us out the new Zyxel router which, in all honesty, is a piece of junk. But one of the first problems I saw with it was the dropping of wireless connections ONLY (on a number of devices, so I knew it wasn't a problem with those). The ethernet connections continued to work fine. Because I'd read the horror stories about the Zyxel I didn't spend much time on it and simply bought the Netgear N150 which was recommended to me by some nice folks on here (It's currently €45 in Argos, which is much cheaper than any other bricks and mortar store).

Anyway, on setting up the Netgear it worked fine for the most part but I noticed that the wireless connection was again dropping (often in the evenings) while the ethernet was fine. I started to worry that the line or even all my devices (daft, I know). I changed an awful lot of settings but didn't think to change the wireless channel from auto because I assumed meant it chose the channel when it first connected. But after quite a bit of reading I realised that the auto channel feature wil change while you're connected.

However, and I'm far from an expert on this, that means the wireless devices have to disconnect and then reconnect on the new channel. Unfortunately this would take a minute or so, which meant it was far from seamless. Clearly what was happening was my router was changing every time a channel became busy etc. which it tended to do in the evenings. Which led to a disconnect. This was happening every ten minutes or so at peak browsing times.

Once I set the channel selection to manual and chose a channel none of my neighbours were using (Xirrus wi-fi inspector is a great free programme for getting that sort of info) my wireless connection has been flawless. Not one drop in a week or so. I tried changing back to auto channel just to confirm and I got two drops in the first half hour. I'm not sure whether that might help with the Zyxel also, but it could be worth a try.

Sorry if that was a bit long-winded but it may help someone.

PogMoThoin

Theres also a wifi analyzer app in the apple and android markets that can give information on what channels are in use nearby.

dub45

Also netstumbler.

http://www.netstumbler.com/downloads/

coylemj

I don't really see the point of those Wi-Fi analyzer programs, I'm running inSSIDer and it says that half my neighbours are using Channel 6 so in theory I should move elsewhere but in fact Channel 6 is the only one that works with my devices.

I have the Cisco EPC2425 (UPC) router and the Wi-Fi channel setting defaults to 'Auto' which seems to mean Channel 1, that's what it always goes to when it boots up with the channel set to 'Auto'. The problem is that on this channel neither my Windows laptop nor iTouch will connect, the only way I can correct the problem is to manually set the channel to 6.

PogMoThoin

Maybe they're set to "super g", this only works on channel 6 and spans all channels
http://en.wikipedia.org/wiki/Super_G_(wireless_networking)

1, 6 and 11 are the 3 non overlapping channels in "b" and "g" mode. Europe uses 1-13, Usa only 1-11 therefore setting to channels 12 or 13 could cause problems for devices meant for the US market only. Japan uses channel 14 only

Deliverance XXV

Same happens to me with UPC. I get regular disconnects. I restart the router and it works fine for a while and then disconnects again. Only thing that seems to fix it is changing channels and then I never get a disconnect (Until I turn the router off for the night and it happens again the next day until I change the channels again.)

coylemj

Deliverance XXV wrote: »

Same happens to me with UPC. I get regular disconnects. I restart the router and it works fine for a while and then disconnects again. Only thing that seems to fix it is changing channels and then I never get a disconnect (Until I turn the router off for the night and it happens again the next day until I change the channels again.)

You get one 'free' restart. By this I mean that if you set the channel manually to (e.g.) 6, the next restart will leave the actual channel used at 6 but the 'new channel' will go back to the default setting of 'Auto'. On the next restart after that the channel will go to '1' so after the second restart you need to go back in and change the settings.

lucernarian

PogMoThoin wrote: »

Maybe they're set to "super g", this only works on channel 6 and spans all channels
http://en.wikipedia.org/wiki/Super_G_(wireless_networking)

1, 6 and 11 are the 3 non overlapping channels in "b" and "g" mode. Europe uses 1-13, Usa only 1-11 therefore setting to channels 12 or 13 could cause problems for devices meant for the US market only. Japan uses channel 14 only

That graph is incorrect. That's for 802.11B mode which is virtually never used anymore. 802.11g uses 16.5MHz bands with a guard band either side I think, and has a -20dB spectral power density at 10MHz either side of f0. The channels are regarded as 20MHz wide using the OFDM 802.11g mode and this means channels 1, 5, 9 and 13 do not overlap for 802.11g. The problem with devices simply having Channels 12 and 13 disabled to them is very real however. A usb dongle I have has this problem, even though the driver has a regional setting option Anyway, ralink and atheros devices seem to be big culprits with this craic. Atheros cards can have 3rd party drivers (like Commview) used instead at least..