Trying to resolve wireless LAN connectivity issues
Somewhat ironically, as I scraped the ice off my car window early this morning, I was prompted to blog about the issues which the summer heat had caused on my wireless (802.11b) network earlier this year. In truth, like many planned posts to this blog, it’s something I’ve been meaning to write about for a while now…
It all started when I tried to make two changes at the same time on my wireless access point (I should know better). After having problems setting up WEP (I got it working, but Windows XP kept on dropping out and re-connecting to the network every few minutes), I tried a firmware upgrade (in the hope that would fix things, or even allow WPA). The firmware upgrade didn’t help and the drop-outs continued, especially with one PC in another room (about 10 metres away but with a few wood/plasterboard walls in between).
At about the same time, we had new next door neighbours on one side, and our neighbour on the other side put a wireless network in his house.
Added to that it seemed that the remote PC would fail to connect whenever the weather was hot…
A lack of WiFi security using WEP/WPA is something I can live with (in the short term – I do use MAC address filtering, but if anyone was that bothered they could monitor traffic, capture a valid address and spoof it), so I set about investigating the other issues, including why hot weather would affect WiFi connectivity! Reading around on the ‘net unearthed a load of advice (but nothing specific about the weather), including the following (mostly from PC World magazine’s article on wireless networks that do more, Netgear’s advice on improving wireless range by tuning equipment, HP’s prevent wireless interference article and Microsoft’s 10 tips for improving your wireless network):
- Picking the best location. Distance, and the objects in between a computer and a wireless access point (WAP) will all affect performance, as will the height above the floor, distance from a wall and proximity to metal objects (including CDs/DVDs!). The fact that my WAP needs to be connected to both power and wired network meant that I couldn’t put it in the middle of the house, but I did manage to move it along the wall so it was a little bit closer to the remote PC.
- Change channels. the 2.4GHz spectrum used by 802.11b is particularly susceptible to interference from items such as microwave ovens, 2.4GHz cordless telephones, power lines, Bluetooth devices, light fixtures and of course other 802.11b networks. Whilst the 802.11b band is divided into 11 channels, each 22MHz wide, they overlap one another and only channels 1, 6, and 11 are totally separate. I wondered if the new networks in the neighbourhood were interfering with ours and after installing Network Stumbler (which I found from the Tech FAQ 802.11 software tools page), I found that one neighbour’s WPA-protected router was using channel 1 and that the other side were using channel 11, so I picked channel 6. I’m not sure how 802.11g is affected (both my neighbours were using 802.11g), but one article I read suggested that 802.11a is less likely to experience interference.
- Boost the signal. I’ve yet to try out the Pringles can antenna idea (or the alternatives from hackaday and Shawn Morton) but 802.11b networks can be boosted by either purchasing an additional antenna, or by just making sure that it is upright (802.11a networks already operate at the maximum permitted signal strength). Other measures include omnidirectional antennas but a new WAP would have been cheaper (and would let me move up to 802.11a/g).
- There’s also a whole load of discussion about the correct Windows XP wireless configuration. None of that really helped (and it was all working fine until it got hot outside and I upgraded the WAP firmware) but there are two interesting threads at Overclockers and ARS Technica.
- Think about what else might be interfering with the signal – even something as innocuous as a stack of CDs, as explained by Don Jones’ cleaning up wireless clutter article.
I still haven’t found out if the weather really does affect WiFi connectivity (I guess it could as extreme weather does affect TV and radio reception) but it seems strange we’ve not had a problem in previous years. If anyone has any ideas I’d be glad to hear them.