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Over the past few months I have been getting an increasing number of requests for help to setup WiFi networks. I am not just talking about the initial setup, but many ongoing reliability problems. At first I was blaming vendors as most of the problems seem to be associated with one vendor, Belkin. However as time went by, I realised the issue was not just Belkin but applied to a lot of other vendors too. The common factor seemed to be the use of the default channel number and changing the channel fixed the issue.

Then the penny dropped when I re-organised my AV kit at home. Wireless Video senders, wireless security cameras and some baby monitors also use the 2.4 Ghz band.

So I thought I would do some investigation along those lines. I was shocked at what I found.

Firstly the 14 WiFi Channels (not all are available in every country see http://en.wikipedia.org/wiki/List_of_WLAN_channels) have massive overlap, so in a busy area lot of interference will result, reducing the throughput in many circumstances.
Secondly the wireless Video channel could not have a worse frequency allocation, and have the potential to wipe out WiFi signals. Especially as unlike WiFi , which sends in bursts and waits for a reply, an AV sender sends a continuous carrier.
I have created the following diagram to demonstrate the frequency clashes

Click on the thumbnail for the full diagram