Cell tracking, mobile GPS and cell phone tracker programs are gaining notice from consumers, cellphone businesses and application designers. The up-to-date mobile phones feature GPS locator functionality to track cellphone position.
To help comply with Federal Communications Commission rules, cellular phone companies have to be in a position to provide authorities with mobile phone latitude and longitude to an precision of 50 to 300 meters. Cell Tower Triangulation fails to always satisfy this requirement. By way of comparison, commercially accessible GPS systems are able to obtain accuracy right down to less than 10 meters. This is dependent upon several factors, as GPS signals are often rather weak and are disturbed by numerous environmental factors. With Mobile Location Services (MLS), the GSM cell network provider uses triangulation algorithms to compute the position of the mobile phone, its accuracy is proven to be less than than that of GPS. MLS is further affected by the same issues as GPS in the sense of the barriers affecting signal strength and the density of GSM towers to assist in the triangulation effort. In remote areas position accuracy may be off as much as a mile.
GPS Hot Start refers to whenever the GPS enabled device remembers its last known location, the satellites which were in range before, as well as the almanac information in memory, and makes an attempt to connect to the same satellites and determine a brand new location based upon the previous information. This is generally the quickest GPS lock but Hot Start only works if the phone is generally in the same location as when the GPS was last switched off. GPS Warm Start is when the GPS enabled handset keeps its last calculated location, and almanac used, but not which satellites were in view. It performs a reset and attempts to lock onto satellite signals and computes the latest location. The GPS receiver has a general idea of which satellites toseek because it kept its last known location and the almanac data helps identify which satellites are in range. The Warm Start will take more time than the Hot Start although not as long as a Cold Start. With GPS Cold Start, the device deletes all the previous data, and tries to locate satellites and attain a GPS lock. This usually takes more time since there is no known reference data. The GPS enabled cell phone receiver has to attempt to lock onto a satellite signal from any accessible satellites.
So as to get better GPS lock times mobile phone manufacturers and wireless providers introduced Assisted GPS technology. It downloads the ephemeris and helps triangulate the device basic location. GPS Receivers can get a faster lock at the expense of a few kilobytes of data transmission. Assisted GPS, also known as A-GPS or AGPS, improves the performance of normal GPS in cell phones connected to the cell network. In the United States Sprint, Nextel, Verizon Wireless, and Alltel all use AGPS. This is a means of using the cellular network to accelerate acquisition of GPS satellites.
A-GPS assists location tracking performance of cell phones (and also other related devices) in two ways:
The first method will be helping to acquire a faster “time to first fix” (TTFF). A-GPS receives and archives information in relation to the location of satellites via the cell network so the location details does not require to be downloaded via the satellite.
The next way is by helping position devices when GPS signals are weak or blocked. Since GPS satellite signals may be interfered with by tall structures, and do not pass through building interiors well Assisted GPS employs distance to cellular towers to approximate location when GPS signals are not accessible.
When satellite signals are not readily available, or accuracy is less important than life of the battery, applying Cell-ID is a useful substitute to GPS cell phone location. The position of the handset can be computed by the cellular network cell id, which recognizes the cell tower the mobile phone is connected to. By understanding the location of this tower, then you can know approximately the place that the handset is. But, a tower can cover a huge area, from a few hundred meters, in higher populationdensity zones, to several kilometers in lower density regions. This is why location CellID accuracy is lower than GPS accuracy. Having said that tracking via CellID still provides quite a helpful substitute.
Another way of calculating cell phone position is Triangulation or Mobile Location Services (MLS). Cell Tower Triangulation uses signal analysis data to compute the time it takes signals to travel from the mobile phone to no less than 3 cell towers to calculate position.
Phone Tracker Fundamentals
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