Mobile Phone Tracking
Mobile phone functioning is based on sending and receiving radio signals from cell sites fitted with microwave antennas. When the mobile phone is turned on, it is registered in the mobile network. The handset receives a strong signal from surrounding stations and is able to switch seamlessly between different sites.
In other words, you are carrying small but very powerful microwave transmitter that makes it possible to identify your location. This is called mobile tracking technology. The system of tracking is based on the satellite work and it is using GSM (Global System for Mobile Communication) and GPS (Global Positioning System) technologies. It processes the data from the towers receiving signal. GPS can not only track the exact location but also compute the velocity and time. Four satellites are needed to determine location from three mobile towers.
Cell phone GPS tracking can therefore be a useful feature for business owners and fleet managers who need to be able to keep track of their vehicle movements. Cell phone GPS tracking can also be a useful feature to the emergency services or police. You can find a lost handset or even a lost person. This is why it was legislated. However it is not available to public usage. It's regulated by the Department of Defense and all the data are restricted.
Mobile technologies go even further. Now you can "mobilize" even your pet. There exist mobile phones for dogs called PetCell which is attached to a collar. Its main function is quick finding the location of your dog with GPS technology integrated to the handset.