| What makes a cell phone a GPS cell phone? The | | | | fewer lost signals from overhead obstructions. |
| first requirement is a GPS receiver. GPS signals | | | | The phone uses a signal from the cell phone |
| originate simultaneously from three to twelve | | | | tower to correct or enhance the satellite signal. |
| satellites orbiting about 11,000 nautical miles above | | | | This wireless assisted GPS, or enhanced GPS, can |
| the earth. The GPS receiver and software sort | | | | sometimes work inside buildings or under heavy |
| out the signals from the different satellites and | | | | forest canopy, both of which are terminal to line |
| pinpoint the receiver's location on the surface of | | | | of sight satellite signals. A disadvantage with the |
| the earth to within a few yards, sometimes | | | | cellular plan is that your GPS will work only in |
| closer. | | | | places that you can get cellular telephone service. |
| More and more cell phones are manufactured with | | | | If you use a separate GPS receiver that connects |
| GPS receivers built into the handset. Cell phones | | | | to your cell phone then you will continue to |
| without built-in GPS receivers can still become a | | | | receive GPS signals regardless of the availability of |
| GPS cell phone by connecting with a separate | | | | cellular service so long as your receiver and the |
| GPS receiver through a USB or serial port or by a | | | | satellites can see each other. |
| wireless Bluetooth connection. Bluetooth is a | | | | Separate GPS receivers usually come bundled |
| specification for wireless, short-range | | | | with software on a SD or similar card that you |
| communication of voice and data between two | | | | insert into a slot on the phone. The software has |
| devices. | | | | the maps that display on your cell phone screen. |
| Both methods can provide turn-by-turn driving | | | | You can continue to receive cell phone calls or |
| instructions, often with voice and illustrated maps | | | | connect to the internet with your cell phone while |
| that show your location on the cell phone screen. | | | | the GPS is working, assuming of course that you |
| The built-in GPS receiver method is more | | | | have the proper subscriptions for doing so. |
| convenient. There are no wires or devices to | | | | The separate GPS receiver method avoids |
| connect and there is nothing to download from | | | | monthly plan fees but you will have to balance |
| your desktop. Attach your GPS enabled cell phone | | | | that against the cost of the GPS receiver and |
| to the windshield holder or pull it out of your | | | | software, which is from $100 and up depending |
| pocket if you are on foot, push a few buttons | | | | on the bells and whistles you want to add. |
| and off you go. | | | | If you live in an area with good cell phone service, |
| You will, however, need a special cellular plan with | | | | and you are a non-technical person, or your are |
| your cell phone service company, and you may or | | | | buying GPS for somebody who would never read |
| may not also need to subscribe to their data | | | | a manual, then the Sprint/Nextel and Verizon |
| service. The usual cost is between $10 and $25 | | | | cellular GPS plans are a good choice. When |
| per month, but that can vary up or down with | | | | purchased as part of cellular plan the cost of a |
| usage. Sprint/Nextel and Verizon provide GPS cell | | | | GPS enabled smartphone is not much different |
| phone service with different features. | | | | than a regular handset, and $10 - $25 per month |
| In addition to convenience, another advantage to | | | | is not unreasonable for the service. |
| a cell phone GPS plan is greater accuracy and | | | | |