wifi access points sense the wireless medium around them before transmitting. If they find it busy, they do an exponential wait, and try again. Thats why ever

wifi access points sense the wireless medium around them before transmitting. If they find it busy, they do an exponential wait, and try again. Thats why everyone can be on channel 11 and things won't be too bad. If they could sense the medium perfectly, routers would always be able to guarantee service regardless of the network congestion just throughput would decrease. However, they can't sense the medium perfectly, so we run into the hidden terminal problem, where wireless packets clobber mid route because they're transmitted by routers far way from each other enough that they can't sense each other. Thats the reason why wifi congestion stops traffic in congested parts of london. Baby monitors/any-analogue device doesn't do this, and that's where the problem comes from. The 5GHZ band (802.11n) is a good alternative. http://en.wikipedia.org/wiki/Hidden_terminal_problem http://en.wikipedia.org/wiki/Hidden_terminal_problem