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Over a large number of sites that our ticket machines (ETM) operated, did not download very well. Since then, I have spent alot of time learning about wireless. Learning how the AP were set up and made changes that proved to resolve the problems.

Cisco 1200 and 1240AG .

Most of the APs had channel settings to least congested over the complete 13 channels. The (ETM) just didnt communicate with the server and the problem was firstly blamed on the AP setup. At the time I was quite inexperienced on wireless and didnt look through the logs. I just experimented with different settings, as I found out what they did. Finding that setting the AP to use Least congested Channel over 1,6 & 11 resolved the problem.

I had a similar experience with the sites that the AP were set to static channels. Resolving this with the same method.

On the second scenario, I know it was a combination of either 2 or more AP with the same channel too close. Or there was a rogue AP from outwith the business on this channel causing interference.

I'm interested to here any opinions / suggestions to why the first scenario would have happened and why my cure worked. As a colleague has a similar situation on his project, although its certainly due to static channel interference. On suggesting the least congested 3 channel choice would allow for the AP to resolve this problem. Another colleague from HQ balked at my idea of using the least congested channels, as ETM cannot communicate with the AP because of the channel checking, it sends the ETM into a state that they cannot communicate and the AP are not able to use channel that its states it is using. I'm not the most experienced wireless guy and my colleague with the issue has no experience. I have no idea the experience of my HQ colleague.

Not being able to fly down and survey the site. I can only give advice on experience I have tried, tested and proved to be an improvement on our ETM.

Any advice on if I'm way off the mark or to explain I am right to suggest my advice would be great. Over and above the fact of I've proved it on the sites I've worked on.

Just because a particular channel is un-used, does not imply that some nearby (overlapping RF signal) channel is a good choice.

I don't have the link to it handy, but the Cisco Website has a paper describing their experiments using Ch's 1, 6, and 11. Any other is asking for more interference and lower throughput !

And as you found out, interference can cause problems with even making the connection to begin with.

If you can find that paper, and show it to your skeptical coworker, I'm sure he/she will be convinced.

Cheers