Without GPS, one way to locate a phone could be through trilateration. However, this would require the phone to be connected to 3 (or maybe even 4?) base stations to accurately obtain the phone's location.
In the case that the mobile phone is not connected to a sufficient number of base stations, trilateration would not work. Is there any way that the location could still be obtained from the base station? Would internet access help in any way?
I have often observed how a phone's location can be obtained by tracing a call made to the phone (in several TV shows and movies, which I agree is not a very reasonable or accurate source of information) and by having the call last for a certain duration, during which the location can be obtained. My primary doubt is: what additional information can be obtained in the packets transmitted between the base station and mobile phone, when compared to the case that the phone is idle (not communicating with the base station)? I was wondering if these packets might contain the needed location information.
Assuming that this technique actually works, how would it? How can tracing a call provide location information, unless the phone is connected to a sufficient number of base stations?