Not everyone who uses a GPS phone does so with the best intentions. Police easily pinpointed the location of a teenager in Tennessee who made multiple prank calls to 911 from a GPS-enabled phone [ref]. Police also arrested a California man who used a GPS phone to stalk his former girlfriend by concealing it under the hood of her car [ref].
The United States Federal Communications Commission's (FCC) Enhanced 911 (E911) program requires that all cell phones transmit their phone number and location when dialing 911. The FCC gave phone manufacturers, service providers and PSAPs until the end of 2005 to comply with this ruling. This is one of the reasons many new telephones have GPS receivers built in, even if they can't provide turn-by-turn directions.
Although the E911 program can help make sure people get help in an emergency, some people have raised privacy concerns about the program. In addition, many PSAPs do not yet have the capability to receive location information from cellular phones.
Nearly all new cell phones sold in America have some GPS receiving capability built in. Those that don't can connect to a server that uses techniques discussed in the last section to analyze their signals and determine their location. This allows the phones to transmit a person's location to a Public Safety Answering Point (PSAP) after dialing 911. But that's all a lot of phones can do with their GPS.
However, some phones have a complete GPS receiver located in the phone or can connect to one with wires or through a Bluetooth connection. These GPS-enabled phones can understand programming languages like Java and can provide turn-by-turn directions or information about nearby businesses and attractions. Others can work like a tracking device. To use any of these features, you must have:
- A GPS-enabled phone or a compatible GPS receiver
- A calling plan that supports transmission of maps and GPS data
- A service plan or software that provides the actual maps and directions or provides information about the phone's location
Common uses for GPS phones include:
- Location Tracking: Some employers use GPS-enabled phones to track their employees' locations, and some business offer location tracking services for GPS-enabled phones. The Wherifone locator phone provides GPS coordinates and can dial emergency phone numbers. Parents and caregivers can track the phone's location by phone or online and can receive notification if it leaves a designated "safe area." Wearable Environmental Information Networks of Japan has also introduced the Dog @ Watch, a GPS watch phone for children.
- Turn-by-Turn Directions: GPS-enabled phones with view screens can often display turn-by-turn directions as well as announce them through the phone's speaker. In general, companies that offer these services charge a monthly fee and use a database of maps to provide the directions. The services are only as good as their database -- outdated maps can provide inaccurate directions. Some turn-by-turn direction services include: TeleNav ViaMoto MapQuest Find Me smart2Go, which requires a separate Bluetooth GPS receiver and a memory card Destinator SP, which is a software package for smartphones
- Outdoor Location Services: Trimble Outdoors offers maps and location-based services for hiking, mountain biking, geocaching and other outdoor activities.
- Other Location-Based Services: Some companies hope to deliver news, coupons, advertisements and other information to cell phone users based on their location.
Some other GPS-enabled phones include:
Follow the links on the next page for lots more information about cell phones, GPS systems and related technology.