Bluetooth Technology Explained

Bluetooth technology has emerged as a top choice for people trying to move towards a more wireless existence. With so many electronic devices in use for the average person, from personal computers and PDAs to cell phones and GPS systems, it can be frustrating when the devices aren't compatible or aren't in sync with each other. In addition, relying on cables and wires to keep things connected can be inconvenient and limit the user's range and mobility. Bluetooth eliminates the need for cables and brings devices together to speak a common language.

Protocol
Bluetooth technology uses an established protocol, or set of rules, to allow devices to talk to each other and exchange information. It uses radio frequencies to establish a connection between devices and then transmits data from one to the other, whether it's photo files from a cell phone to a computer or a clear voice connection from a cell phone to a headset. The general Bluetooth proximity range is 30 feet, although some high-power Bluetooth devices can communicate up to 100 feet.

Frequency-Hopping
In order to establish a secure connection between devices, Bluetooth sends data within a set range of radio frequencies. If Bluetooth just stuck to one frequency, there could be interference from other radio technology, or it could be easy for someone to highjack the frequency and steal information. Frequency hopping is utilized in Bluetooth communication to keep the communication strictly between identified and accepted devices. The low-power radio waves cycle from one frequency to another at blinding speeds-about 1,600 per second. This rapid shifting significantly reduces the chance of interference; if something did conflict, it would barely be noticeable by the user. The Bluetooth device will automatically avoid bad or weak frequencies.

Bluetooth security works by letting two connected devices know the pattern of the changing frequencies. Without that pattern, another device can only pick up occasional bits of information that sound like radio noise. The data that's being transmitted cannot be decoded by other devices because they can't follow the changes in frequency. 

Bluetooth Core Specification Versions
The core specification is a set of performance rules that applies to all Bluetooth devices; without them, Bluetooth wouldn't function as well as it does. There have been several versions of Bluetooth technology as the specification have changed and improved over the years.

The first versions, Bluetooth 1.0 and 1.0B were early versions that didn't have practical applications and featured too many problems for consumer use. Version 1.1 was the earliest successful Bluetooth specification for consumer use. Version 1.2 featured more advanced technology, such as faster transmissions speeds. Version 2.0 has an enhanced data rate (EDR) and trnasfers information more than three times faster than earlier versions. It also consumes less power and is backwards-compatible with all earlier Bluetooth versions.