calculating location of a mobile phone not by using GPS

guys i am trying to develop an Java application for calculating the location of user through his Java phone, not by using GP开发者_如何学CS, that location can be used later for my research in same project, please help me by your current knowledge about this topic for my project, you can mail me the data regarding this at cooshh@gmail.com or just tell me from where should i start this?? thanx in advance .....

There are only four ways to determine the position of a cell phone.

• An internal GPS. This is the most accurate method.
• WiFi location. The phone is within the range of the WiFi signal.
• Cell tower triangulation. As the name implies, 3 or more cell towers in different directions have to be in range of the phone for this to work.
• Cell tower location. This is the least accurate method, as a phone could be anywhere within the range of the cell tower.

One of my students did this, on a Sony Ericsson in Sweden, by retrieving the cell id. It was not possible to get a list of the locations of all the cell towers (trade secrets! terrorists! national security!), but Google knows surprisingly much, and there was a Google API that actually returned the longitude and latitude of the cell tower.