“Wifi” is a truly ubiquitous technology, and one we often take for granted. And the current standards solve some tremendously complicated challenges. 802.11N for instance includes standards for using beamforming to improve connectivity in the complicated, and changing environments WiFi.
A group of hackers have done a visualisation experiment, to display small-scale variability in signal strength, and the results are intriguing.
The final 3d map is of a tiny area, with huge “caverns” of low signal. This gives a neat indication of the challenges device manufacturer’s face. Now, it’s quite possible that this result is in part biased by the small size of the test device’s antenna. It would be interesting to see a phone-based equivalent. Because of the nature of modern wireless networking protocols the quantity, spacing, quality and shape of antennae on a device will likely impact the size and frequency of these wireless “holes”.