easy to think that way, but someone will start applying sidebands to those and start cutting them up. (Well, I expect that.) And in Radio, there is a center strong and dropping signal strength off to both sides. So, there actually are 11 channels, and in the right circumstances, most will be useable. Treating them as only have three channels available, reduces interference until you have multiple sources using the same channels because they also think that only 3 channels are useable. At my Piano Teacher's house, there were about 12 nearby WiFi networks in easy range of my laptop. (ipads don't seem as sensitive.) At my home, I only see my own networks. (I use istumbler.)
