Skyhook started doing this in 2003; their technology was used in earlier iPhone models to determine location without using GPS. https://en.wikipedia.org/wiki/S

Skyhook started doing this in 2003; their technology was used in earlier iPhone models to determine location without using GPS. https://en.wikipedia.org/wiki/Skyhook_Wireless https://en.wikipedia.org/wiki/Skyhook_Wireless EDIT: used by iPhone OS until version 3.2: https://www.wsj.com/articles/BL-DGB-16945 https://www.wsj.com/articles/BL-DGB-16945