Location-Based Services (LBS) are becoming very prevalent in the last few years
, especially since smart phones are becoming so popular. There are 8 different types of LBS technologies, and some are more attractive than others. Call Identification is one type. This can be a very accurate method depending on how many cell towers are in an area. This can be great if you are in an urban area with more cell towers vs. being in a very rural area where there are fewer towers. Enhanced Cell Identification is another method that is being used. You can get roughly the same accuracy with Enhanced Cell Identification as Cell Identification in urban areas, however, since the cell towers are so close together.
There is also the option of using Uplink-Time Difference on Arrival (U-TDOA). The network will determine the difference in time and therefore the distance from each base station to the mobile phone. Time of Arrival (TOA) can be used. This is the same as U-TDOA; the difference is this method uses the actual time of arrival at the tower rather than the mileage difference between two towers. Angle of arrival (AOA) can be used to track cell phones as well. The AOA system identifies the location of the cell phone where the angle lines of the towers meet. E-OTD can be used. The precision of these systems highly depends on an area's saturation point of towers. Assisted-GPS uses a live-person from a strategically placed ground station to identify and correct for errors in the system caused by the locales characteristics and situational atmosphere. Assisted-GPS positioning systems will normally use a fall-back method when a person goes indoors, in a tunnel or in another underground or covered situation. Hybrid position systems combine these methods to identify locations.