Bluetooth® technology is a trademarked name for a wireless networking protocol. In most cases, Bluetooth® technology appears in wireless personal area networks (PANs), which are networks that connect personal electronics devices over a short distance. Essentially, Bluetooth® uses short-range wireless communications to replace cables required to connect devices. The Bluetooth® devices connect to other devices automatically when they move within range of each other, making this technology easy to use for anyone, regardless of their level of experience with technology. Devices that work well inside a Bluetooth® PAN include cell phone hands-free headsets, a wireless mouse or keyboard for a computer, and video game consoles.
Formed in 1998, the Bluetooth® Special Interest Group (SIG) oversees development of and changes to the Bluetooth® protocols. Engineers for the Swedish firm Ericsson Mobile Platforms developed Bluetooth® technology in 1994. Early Bluetooth® specifications didn’t work well, but after a stabilized version appeared in 2002, products began appearing in the market.
As many as eight Bluetooth® devices, including both mobile and stationary devices, can be connected at one time. This technology has advantages over other types of wireless protocols because it is inexpensive to employ and because it does not require line of sight between the devices, as does infrared. However, Bluetooth® cannot match the distance or speed of some other wireless protocols, such as WiFi.
The wireless technology behind Bluetooth® is called frequency hopping spread spectrum. Essentially, frequency hopping involves dividing data to be sent over the PAN into small chunks. Bluetooth® technology then allows the chunks to travel over any one of 79 different wireless frequencies. By using multiple frequencies, the PAN using Bluetooth® can send the data in the most efficient manner possible and can avoid temporary interference from other devices on some of the frequencies. The Bluetooth® PAN works over the 2.4 GHz microwave radio frequency bandwidth, which is unlicensed and available for use by any device.
Security concerns were prevalent with Bluetooth® technology in its early years, leaving user data sent over the PAN in danger of being stolen. Most of the early security problems were related to the hardware making use of Bluetooth®, rather than to the protocols themselves. A Bluetooth® virus initially appeared in 2004. Most of Bluetooth’s security concerns have been fixed in recent years, although various problems continue to appear from time to time.
Bluetooth®’s founders named the technology after a 10th-century king of Denmark and Norway, Harald Bluetooth. The king supposedly attempted to unify warring tribes in Denmark and Norway. The Bluetooth® founders envisioned their technology unifying difficult-to-use wireless technologies, making it easier for different types of devices to exchange data.