Technology Created for Emergency Response May Be Used for Keeping Track of Your Teenagers. GPS tracking, cell phone GPS and mobile phone tracking software are undoubtedly attracting interest from consumers, cellphone companies and software coders. The up-to-date cell phones have GPS locator functions to track cellular phone position.
In order to abide by Federal Communications Commission rules, cellular phone companies must be in a position to provide authorities with cell phone latitude and longitude to an accuracy of 50 to 300 meters. Cell Tower Triangulation does not always meet this requirement. By way of comparison, commercially available GPS modules can acquire precision right down to 3-10m. This relies on many factors, as GPS signals tend to be quite weak and are disturbed by numerous environmental factors. With Mobile Location Services (MLS), the GSM cellular network provider uses triangulation algorithms to determine the position of the mobile phone, its accuracy is proven to be much worse than that of GPS. MLS is also affected by factors similar to GPS in the sense of the interference affecting signal strength and the density of GSM towers to assist in the triangulation calculation. In rural areas location accuracy may be off as much as a mile.
GPS Hot Start refers to whenever the GPS enabled device recalls its last calculated location, the satellites that had been in range at the time, together with the almanac information in memory, and attempts to find the same satellites and calculate a fresh location based upon the previous information. This is generally the quickest GPS lock but Hot Start only works if the phone is in the same general area as when the GPS was last turned off. GPS Warm Start means whenever the GPS enabled cell phone remembers its last known position, and almanac used, but not which satellites were in view. It performs a reset and tries to find satellite signals and computes a fresh location. The GPS receiver has a general idea of which satellites tolook for because it saved its last known location and also the almanac data helps identify which satellites are in range. The Warm Start is going to take longer compared to Hot Start although not as much as a Cold Start. With GPS Cold Start, the device deletes all the previous information, and tries to find satellites and accomplish a GPS lock. This normally takes more time because there is no known reference data. The GPS enabled device receiver must try to lock onto a satellite transmission from any accessible satellites.
As a way to have improved GPS lock times cellular phone manufacturers and wireless operators introduced Assisted GPS technology. It downloads the ephemeris helping triangulate the smartphone basic position. GPS Receivers will get a quicker lock in exchange for a few kilobytes of data transmission. Assisted GPS, also called A-GPS or AGPS, enhances the performance of normal GPS in mobile phones connected to the cellular network. In the US Sprint, Nextel, Verizon Wireless, and Alltel all use AGPS. Which is a means of utilizing the cell network to speed up acquisition of GPS satellites.
A-GPS assists location tracking functions of cell phones (along with other related devices) in two ways:
One way is by helping to acquire a more rapid “time to first fix” (TTFF). AGPS receives and archives information regarding satellite location using the cellular network so the position data does not need to be downloaded from the the satellite.
The other method is by helping position cell phones when GPS signals are weak or impeded. Since GPS satellite signals may be interfered with by tall buildings, and do not pass through building interiors well Assisted GPS uses proximity to cellular towers to estimate position when GPS signals are not available.
When satellite signals are not accessible, or precision is less important than battery life, making use of Cell-ID is a viable substitute to GPS mobile phone location. The position of the cell phone might be determined by the cellular network cell id, which recognizes the cell tower the cellphone is using. By having the position of this tower, you may know roughly the place that the smartphone might be. Still, a tower can cover a large area, from a couple of hundred meters, in high populationdensity regions, to a few miles in lower density zones. This is the reason location CellID precision is lower than GPS accuracy. Nevertheless tracking via CellID still can provide a truly handy alternative.
Another method of determining device position is Triangulation or Mobile Location Services (MLS). Cell Tower Triangulation uses signal analysis data to compute the time it takes signals traveling from the cellular phone to a minimum of 3 cell towers to estimate position.
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