BENEFITS OF BLUETOOTH TECHNOLOGY
FOR ROAD NAVIGATION

Abstract
The Bluetooth promise is to replace the cords that often clutter the home computer system. For a car it can solve some tricky GPS installation problems as well as providing convenience for the user. The article will explore these topics and should also provide a ground work for more discussion. For example, a traditional GPS may be difficult to position on the back shelf of a car while a Bluetooth GPS can solve the problem easily.

What is Bluetooth?
Bluetooth is a wireless communication system that is designed to replace the wires used to connect devices together in a traditional electronic system. Generally the wires would have been used to create point to point serial connections, networks of computer systems, peripheral I/O connections such as a mouse or keyboard, headsets for communication use, and other uses.

Bluetooth GPS
A typical GPS receiver connects to a computer using a serial connection. Bluetooth can replace the wire used for this connection with a Bluetooth single point connection that mimics the wire providing the ability to transfer of information between devices. While bi-directional transfer is possible in a connection the GPS receiver generally only sends signals to the computer which is just a listener. The computer can be a traditional desktop/laptop system or a PDA. A growing number of PDA¹s have Bluetooth capability built in or it can be added via a CompactFlash card. Other connections are also possible.

The idea is that the GPS is connected via a Bluetooth manager that provides all of the services to ensure the connection is sound and the application only needs to treat this connection like it was a simple serial port. This becomes a two step process.

1.The data is sent from the GPS to the Bluetooth hardware and is interpreted by the Bluetooth driver. The driver behaves like an I/O serial port connection within the system. It creates a pseudo serial port.

2. The application hooks to the serial connection created by the Bluetooth driver and accepts the data sent by the GPS receiver.

The GPS receiver is autonomous and contains its own power. Generally this consists of a built in battery augmented with an external power connection of long run times are needed. It also has its own on/off switch. While having external power does require a wire there is no need for this wire to come from the PDA. It is possible to hardwire the power for the GPS directly to the vehicle power via a 12 V to 5 V or 3V adapter.  If this power is live all the time and the car is kept where GPS signal can be received then the GPS itself can remain on which will significantly reduce start up times. This means you can jump in the car, connect the PDA or computer and be off an running since the GPS already has a computed position. Even if the power is not on all the time the time can be reduced since the GPS will start acquiring information as soon as it is turned on with having to wait for the PDA to be set up. Of course, short sops will not require turning off the GPS since the battery will last several hours.

The GPS is fairly small and can be mounted in a convenient place to receive GPS signals. This could be well forward on the dashboard to make full use of the windshield or it might be on the back deck using the rear window for access to the sky. Since there is no need to hook the GPS directly to the PDA there are many possible mounting positions. The GPS could even be out of sight under the deck. The PDA itself can be positioned where it provides the best view for the operator without worrying about GPS reception. The PDA can be removed without worrying about disconnecting the GPS receiver. This freedom is one of the main advantages of the Bluetooth GPS/PDA combination.