iPhone Cellular Triangulation For Current Location

I want to get the 开发者_运维问答current location of iPhone from GPS and Cellular network. Is it possible to get the location from cellular network in iPhone. Please tell me any tutorial.

http://www.switchonthecode.com/tutorials/getting-your-location-in-an-iphone-application

The iPhone uses wifi access points, cellular towers and gps depending on what's available and provides the information more quickly. This all happens in the background using the Core Location framework which the tutorial above covers.