Many iPhone users may have wondered why Apple prompts them with a message saying “Location accuracy is improved when Wi-Fi is turned on” each time they choose to turn Wi-Fi off. Why does a phone that has GPS (Global Positioning Satellite) capability need to use Wi-Fi to determine it’s location? The reason is fairly simple. There are of course thousands of radio frequencies traveling through the walls of buildings all around us. What makes Wi-Fi frequency (or even bluetooth) particularly useful for location mapping is that the frequency travels a relatively short distance before it decays, due to how low energy the Wi-Fi wavelengths are. A combination of three or more Wi-Fi signals can be used in a very small area by a phone to triangulate locations on a map in the same manner that earthquake shockwave strengths can be used to triangulate epicenters. Wi-Fi hubs don't need to transmit their locations to be useful. Most are oblivious of their loc...
Musings on web development, apps and the future of the internet.