British telecom regulator Ofcom has commissioned a report that concludes that WiFi performance in central London can be up to four times slower than that found in less densely populated areas. Although users of WiFi have blamed nearby networks for much of the interference in the 2.4-GHz WiFi band, the authors of the report pin the primary sources of interference on cautious parents using analog baby monitors, tired citizens watching retransmitted TV in their bedrooms, and microwave ovens. The report notes that in central London, there are too many networks with resends, beacons, and housekeeping filling 90 percent of the data frames sent over WiFi, thus leaving only 10 percent for users’ data. Another source of WiFi trouble is caused by London’s “Free Public Wi-Fi” points that are sending out beacon frames ten times more frequently than they should (every 0.01204 seconds) resulting in a significant amount of traffic on the WiFi band. Further complicating the situation is the fact that the makers of inexpensive unlicensed devices such as analog baby monitors or remote switches have no real incentive to develop more expensive digital models that cause less interference.The entire 93-page report can be viewed online.
Urban WiFi Interference
