Using the GPS for People Tracking
Until recently, tracking people with Global Positioning System technology required purchasing expensive hardware and software. Now, complete solutions are available through cellular service providers. Here is background info and a few options for keeping up with the whereabouts of your family, friends and employees.
Locating People in an Emergency
The increased demand for enhanced 911 (e911) emergency calling capabilities, stimulated by the events of 11 September 2001, has pushed forward GPS tracking technology in cell phones. At the end of 2005, all cell phone carriers were required to provide the ability to trace cell phone calls to a location within 100 meters or less.
To comply with FCC requirements, cell phone carriers decided to integrate GPS technology into cell phone handsets, rather than overhaul the tower network. However the GPS in most cell phones are not like those in your handy GPS receiver that you take hiking. Most cell phones do not allow the user direct access to the GPS data, accurate location determination requires the assistance of the wireless network, and the GPS data is transmitted only if a 911 emergency call is made.
So, in general, you can not track someone using their cell phone, unless the person you want to track has the right kind of cell phone, connected to the right network, with the right service.
GPS-enabled Cell Phones:
Motorola and Blackberry were the first GPS-enable phones to proliferate the United States. Initially, Motorola"iDEN" phones were commonly used for employee tracking on the business-oriented Nextel network. Then GPS enabled Blackberry phones, once used almost exclusively by corporate and government VIPs, began to penetrate the consumer market stimulated by the demand for phones with advanced messaging capability. Next came specialty devices produced under the names of "Disney Mobile" and "Wherify Wireless" targeting use by children and elderly. Now in 2008, a variety of GPS-enabled phones and tracking services are available, as you can see from the ads on this page.
Wireless Networks
Here in the United States, the wireless networks used for GPS tracking are primarily those operated by cell phone carriers. It is not likely that you as an individual will negotiate network access with a carrier. It is more likely that you will select a solution including a cell phone provisioned to communicate in a certain way on a specific wireless network. List below are a some carriers I recomend for use with GPS cell phones and services.
T-Mobile / Cingular / AT&T – The Global System for Mobile (GSM) communications as adopted by these carriers represents the network with the largest coverage footprint. Roaming agreements between these carriers provide end users with service throughout the country. GSM is also the prominent cellular network abroad.
Sprint / Nextel, not so much because of coverage, but because of their emphasis on data. Nextel has created their own data formats and communication protocols for high bandwidth mobile electronics applications. This company, who gave new meaning to the term “walkie-talkie”, provides the most flexibility for the communication of GPS data between cell phones and location-based service providers. Recent co-operation between Sprint and Nextel has increased this network's footprint.
Location-Based Services (LBS)
LBS providers have agreements with the wireless network carriers to receive data from a cell phone and make it accessible to you via an Internet web site or call center. Most all LBS providers will be able to tell you the approximate last known location, but beyond that, services offered will vary, depending on the type of cell phone and the capabilities of the service provider.
Accutracking
Accutracking is a full-featured low-cost LBS provider using Motorolla, Boost Mobile and Blackberry phones operating on the Sprint/Nextel network.
See Accutracking.com
Sprint’s Mobile Locator
Nextel’s Mobile Locator is a service used in conjunction with Nextel calling plans with Nextel GPS-enabled phones. Mobile locator allows you to view and monitor your peoples’ location in real-time, either singly or within a group, on a zoomable, online map. The web interface allows you to view location history, based on your most recent queries. See: Sprint Mobile_Locator web site for more info
Mapquest Find Me
Using certain models of Nextel phones, you can view a group of your peoples’ locations on one map, or you can view a track of an individual’s location history. Powered by uLocate, Mapquest provides a web interface for mobile devices like PDAs as well cell phones. Other features include in-depth location history detail. See www.mapquestfindme.com
Wherify Wireless
Developers of the "Wherifone" designed specifically for children and seniors. The Wherifone is supported solely by Wherify's Global Location Service Center. See: Wherify.com
Other Things to Keep in Mind
Here are some other things to keep in mind when deciding what products and services are right for you:
Permissions and Privacy
Simply put, tracking someone without their knowledge can get you in trouble. Typically, the subscriber must give permission and the cell phone must be enabled for tracking. Consult with your service providers for more detail.
Tracking Application "Persistence"
Again, the tracking application on a cell phone typically must be enabled by the user. Depending on your equipment, the application may persist - remaining enabled when the phone is turned on after having been turned off. This feature is particularly handy if you do not want to instruct the person using the phone how to turn tracking on and off.
Passive Tracking
Some tracking devices will record location data internally so that it can be downloaded later. Also referred to "data logging," which can provide location data even when the device has traveled outside the wireless network. Passive tracking is not a common feature built-in to cell phones (at the time this article was published), but more sophisicated java-enabled cell phones, PDAs, and other mobile devices may have this feature. You should ask your LBS provider if their appilication can accomodate passive tracking data from the more sophiscated tracking devices.
Assisted GPS (AGPS)
Some cell phones can receive ephemeris information on the GPS satellites, which speeds up the initial position fix. AGPS information may also help in finding satellites and getting positions in difficult conditions. To have AGPS features, your services must be set up to provide AGPS information to your cell phone and your cell phone must be able to process AGPS information.
Tower reports
In the absence of an accurate GPS location, service providers may record the location of the nearest cell tower. Check with your LBS to determine if Tower locations are used to determine cell phone locations.
GeoFencing
GeoFencing is a term used to describe a feature that enables the cell phone to only start tracking when it has entered or exited a predefined region, avoiding unnecessary tracking when your people are close to home, office, or school. Or GeoFencing may also mean that an alert is sent when their phone crosses a virtural fence. For example, AccuTracking will send email or SMS message when they move across the designated areas.
Speed Alerts
Some LBS providers provide email or SMS message alerts when specified speed limits are exceeded.
Tracking Map Quality
Most location services do not produce their own maps. Instead they purchase or license mapping products from other companies. Several popular services use Mapquest maps. Indeed, Mapquest can produce a map for just about anywhere in the world, but your service provider's license may be limited to United States. Microsoft MapPoint and Tiger map data are also popular for applications in the United States. If choosing between LBS providers, compare what the maps will look like.
Aerial photos – You can’t get street names from an aerial photo but you can get a better idea of the surrounding environment. The better location services will provide both maps and aerial photos.
Usage Costs
The costs associated with using the GPS for people tracking, include equipment costs, setup/activation fees, and usually network access subscriptions. In addition, your location service may charge for each location report or allot you a limited number of reports and charge you a premium for overages. For example Disney Mobile includes 5 location reports each month, but unlimited reporting is available as an optional plan.
Mobile to Mobile Tracking
Some tracking solutions enalbe you to access tracking maps on a mobile device. The ability to track someone using a using a cell phone, by using another cell phone, conjures up a chase scene from an old movie, where our hero is sitting in the back seat of a moving car with a radar-type device in a briefcase, shouting turn-by-turn directions to the driver in hot pursuit of evil villains.
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I hope this helps!
- Doug
Updated: April 2008
