Different Approaches to Being a Cell Phone Tracker Raise the Question: Do you really know where they are?

Mobile communications means more than just making a phone call while moving.    The latest mobiles include GPS position features to track phone location.   These features, and others such as text messaging, web access and the capability to utilize other software make mobile phones great gadgets.  However GPS satellites aren’t always available, such as when the phone is in a building such as an office, mall, or even in an automobile.  That doesn’t mean smartphone tracking isn’t possible, but it does mean there are other methods of being a tracker.

To track a cell phone involves several main methods of calculating  cell phone location.  GPS Global Positioning System-Satellites, Triangulation, and CellID.   All these technologies convert smartphones into mobile tracking devices.   These systems can be viewed as Network Based, Handset Based or a Hybrid approach.  GPS location is Handset based as it requires software programs installed on the smartphone  along with GPS hardware.  Triangulation and CellID are Network Based as they use the equipment and data from the cellular provider.  Hybrid systems combine methods to make best use of available data and to make position mobile phone tracking faster.  

GPS on cell phones is what people usually think of when considering locating mobile phones.   GPS (Global Positioning System) using satellites is the most well known and more accurate method of tracking.   However GPS needs satellites to be in direct line of site of the cell phone. 

It doesn’t work particularly well indoors or in crowded cities. 

If driving the signals might not reach the mobile phone.  Some cell phones will store the last known GPS location, others might not.  

Another thing with smartphone GPS tracking is the possibility of draining the battery.  It is important to be able to remotely adjust how often of taking GPS position.  Selecting real-time or periodic sampling affects both the resolution of finding position as well as how long the battery will last.  

GPS receivers, whether in a smartphone, or a dedicated GPS tracking device, calculate location by precisely timing the signals transmitted by GPS satellites.  This information includes the time the message was transmitted, precise orbital information (the ephemeris), and the general system health and estimated orbits of all GPS satellites (the almanac).  GPS receivers often take longer to become ready to navigate after being turned on because it must acquire some basic information in addition to capturing GPS satellite signals. This delay is sometimes caused if the GPS device  has been turned off for days or weeks, or has been moved a significant distance while turned off for.  The GPS must update its almanac and ephemeris data and store it in memory.  The GPS almanac is a set of data that every GPS satellite transmits. When a GPS receiver has current almanac data in memory, it can capture signals and determine initial position faster. 

GPS Hot Start is when the GPS enabled handset  keeps its last known position, the satellites that were in view at the time, the almanac information in memory, and makes an attempt to find the same satellites and compute a new position based upon the previous data. This is usually the quickest GPS lock but Hot Start only works if the phone is generally in the same location as when the GPS was last turned off. 

GPS Warm Start is when the GPS enabled smartphone  remembers its last calculated location, and almanac used, but not which satellites were in range. It resets and attempts  to find satellite signals and computes a new position. 

The GPS receiver narrows the choice of which satellites tolook for because it stored its last known position and the almanac data helps identify which satellites are within view. The Warm Start will take more time than the Hot Start but not as long as a Cold Start. 

With GPS Cold Start, the device dumps all the previous data, and attempts to locate satellites and accomplish a GPS lock. This takes the longest because there is no known reference information.  The GPS enabled device   receiver has to try to lock onto a satellite signal from any available satellites. 

Assisted GPS, also known as A-GPS or AGPS, enhances the performance of standard GPS in mobile phones connected to the cell network.   It downloads the ephemeris and helps triangulate the device   general position.  GPS Receivers can get a faster lock in exchange for a few kilobytes of data transmission.

A-GPS assists location tracking functions of smartphones (and other connected devices) in a couple of ways:

One way is by assisting to obtain a faster “time to first fix” (TTFF). Assisted GPS acquires and archivesdata about satellite locationusing the cell network so the position information doesn’t require to be downloaded via the satellite. 

The next method is by helping position  handsets when GPS signals are weak or blocked.  As discussed above GPS satellite signals may be impeded by tall buildings, and do not penetrate building interiors well. AGPS uses proximity to cellular towers to calculate location when GPS signals are not available. 

If satellite signals are not available, or accuracy is less important than battery life, using Cell-ID is a good alternative to GPS mobile phone location.  The position of the handset can be calculated by the cellular network cell id, that identifies the cell tower the phone is connected to.   By knowing the position of this tower, then you can know approximately where the handset  is.  But, a tower can cover a huge area, from a few hundred meters, in high density areas, to several miles in lower density areas. This is why location CellID precision is less than than GPS accuracy. Nonetheless tracking using CellID still presents a very viable substitute.    

Another way of formulating  mobile phone position is Triangulation or Mobile Location Services (MLS).  Cell Tower Triangulation uses signal analysis data to calculate the time it takes signals to travel from your phone to at least three cell towers to estimate position.   

To comply with Federal Communications Commission guidelines, cellular phone companies must be able to provide authorities with handset latitude and longitude to an accuracy of 50 to 300 meters.   Cell Tower Triangulation doesn’t always meet this requirement.  By way of comparison commercially available GPS modules are able to achieve accuracy down to less than 10 meters.  This depends upon many factors, as GPS signals are often very weak and are affected  by many variables.   With Mobile Location Services (MLS), the GSM cell network provider utilizes triangulation algorithms to calculate the location of the mobile phone, its accuracy is proven to be less than than that of GPS.  MLS is also impacted 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. 

Generally speaking it comes down to what location tracking system is available, and the requirements for accuracy.  Hybrid methods are emerging that use various techniques in tandem to provide best available location given available resources.   Generally the application determines the location with a GPS receiver and transmits the tracking data to a server through a data connection. The data connection to the server is usually made over the Internet.  How often GPS samples are taken and how often and by what method the data is sent to the server impact usefulness and costs. 

Keep in mind that there is a basic difference between cell phone GPS Tracking and Navigation.  GPS mobile phone tracking is usually associated with someone keeping records of either real-time or historical smartphone  position, while Navigation deals with the smartphone  user figuring out how to get from point A to point B.

A really great software package that includes remote control of device settings, and combines Mobile Phone Tracking  with SMS text message, Call Log,  MMS multi-media message monitoring, and a web account for storage and review is PhoneBeagle.  

Follow this link if you are interested in    Cell Phone Monitoring Software  compatible with BlackBerry  and  Android  Smartphones, used or Parental Monitoring and Small Business Employee Monitoring .  

Visit this link for more information regarding the latest software for
GPS Tracking .