Low-cost or price-sensitive mobile phones often come without GPS or Wi-Fi. These phones are meant to do what mobile phones are intended to be used for Talk. However, location of the user can still be detected on such phones using cellular towers. Cell-ID positioning and cell tower triangulation are two different ways to get location information from cell towers. Cell-ID result accuracy is only 200-1000 meters; hence it is used as the last option for most location-detection methodologies.
Cell-ID positioning uses your mobile network's cell tower to find your location. This involves the nearest tower to which your phone connects when you place calls. Cell tower triangulation on the other hand uses all the cellular towers around you to calculate your position, based on the signal strength your phone receives from each of the towers. Triangulation is more accurate, however it is a slower process.
Note
It is important to acknowledge privacy and security issues for end users while developing your applications and choosing the type of location-detection and storage. In July 2001, CNET discovered that Microsoft had collected the location data from millions of smartphones, laptops, and other Wi-Fi devices, which was easily accessible on the Web (http://news.cnet.com/8301-31921_3-20085028-281/microsofts-web-map-exposes-phone-pc-locations/). Microsoft rectified it in response to the CNET report (http://arstechnica.com/microsoft/news/2011/08/microsoft-locks-down-wi-fi-location-service-after-privacy-concerns.ars) but this has been an eye-opener for user privacy and security watchers.
