- Standard 802.11b/g hardware can make use of up to fourteen 802.11b/g wifi channels in the 2.4Ghz ISM band.
- Each channel is essentially up to 22Mhz "wide", thus, at most three channels may be used in a particular location without significant "overlap" (such as channels 1, 6, and 11).
- Simultaneous activity on overlapping channels can cause interference, resulting in overall performance degradation (slower speeds, lost connections).
- Most 2.4Ghz wifi equipment is factory set to use channel 6, making it one of the most frequently used 802.11b/g channels.
- Microwaves are well known for interfering with wifi. They operate at 2450Mhz, which corresponds approximately to channel 9. Microwaves can cause measurably significant interference on channels 7 through 13, though channels 8 through 11 are affected the most.
- Lower EM frequencies have longer wavelengths, and thus longer range at the same signal power. Admittedly, the difference between channel 1 and channel 14 is only 72Mhz, which is fairly trivial difference at 2.4Ghz. I suppose it's also arguable that lower frequencies have lower bandwidth capacity?
Note: I'm only using 802.11g because I prefer the Flexview display in my older R51 Thinkpad, which only supports 802.11g wifi. I'd certainly be using 802.11n otherwise, which doesn't face the same interference problems, partially due to its ability to use multiple frequency bands.
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