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HOW TO TRIANGULATE CELL PHONE

how to triangulate cell phone

Location-based services (LBS) are offered by some cell phone networks as a way to send custom advertising and other information to cell-phone subscribers based on their current location. The cell-phone service provider gets the location from a GPS chip built into the phone, or using radiolocation and trilateration based on the signal-strength of the closest cell-phone towers (for phones without GPS features). In the UK, networks do not use trilateration; LBS services use a single base station, with a 'radius' of inaccuracy, to determine a phone's location.

One example of a location-based service might be to allow the subscriber to find the nearest business of a certain type, such as an Italian restaurant. The ability of the restaurant to send an invitation to bypassers has also been mentioned, even though this might be regarded as unsolicited commercial email or spamming. AT&T, Cingular, and T-Mobile triangulate a location from the strength and timing of signals from nearby cell-phone towers. These services were launched in the late 1990s, and (as of 2004) the development in this area seems to be driven more by technical ability than by user need.

With the passing of the Can Spam Act in 2005, it became illegal in the United States to send any message to the end user without the end user specifically opting-in. This put an additional challenge on LBS applications as far as 'carrier-centric' services were concerned. As a result, there has been a focus on user-centric location-based services and applications which give the user control of the experience, typically by opting in first via a website or mobile interface (such as SMS, mobile Web, and JAVA/BREW applications).