With limited inexpensive gear hackers could readily find where you as well as your mobile phone are without you having any notion. At least this is the decision of a recent study out of the University of Minnesota.
It all rests on the basic fact that the mobile phone network has to monitor your mobile in just a certain broad range so resources can be prioritized by it to supply the greatest service possible. (Most people are aware of the fact that providers must give up such location information when subpoenaed by law enforcement agencies.)
Then when a call is available in to you, the broadcasting tower will send a signal to your phone and waits for you personally to respond. A hacker has the capacity to intercept that sign before you even hear it to be answered by the call.