Linksys has introduced a new WiFi amplifier — of dubious legality, I fear — that boosts the signal of your access point to get it through walls and over great distances. I am of mixed feelings on this. On the one hand, there are times when turning up the gain makes a lot of sense and does no harm (for example, if you live on a farm and want to get the signal in the main house to radiate through the barns and so on, and are confident that this won't interfere with anyone else's activity due to your remoteness). On the other hand, this sort of technology, if deployed in a dense area, would interfere with the signals generated by other APs that might be preferable for some users — say, because your network is closed and others' are open.
Ideally, the gain (and channel selection) would be adaptive, shouting as loudly as it can without interfering with any other signal on the band. This is basically what Cognitive Radio is supposed to do. I wonder, though — imagine that I am using channel foo and shouting at bar decibels. I feel secure in doing so because I cannot detect any signals in normal range of me on foo that are attempting to use the band. What if there is someone out there, in range of my emissions, that is communicating at very low power (sufficient to send positional and click signals from a mouse to a CPU a few inches away), on channel foo? I'm not a radio engineer, but this seems like a plausible scenario to me — wouldn't I, despite my best efforts to be a good citizen, drown out the signals of those whose communication was too low-powered for me to hear?
(via /.)
