Smartphones, headsets, keyboards, mice, game controllers, stereos - you name the device, it's probably connectable via Bluetooth. Bluetooth has made massive inroads because of the ease with which it links devices. Basically, just plug it in and wait for the indicator light. Despite some drawbacks - it can be a gateway for dangerous malware and doesn't have much of a range - it's practically ubiquitous.
Once set up, it can be used to transfer data between mobile phones or to send music from a mobile device to a pair of loudspeakers. "Bluetooth is used anywhere where two devices have to exchange data across a distance and cables would just get in the way," says Matthias Schaefer of the Fraunhofer Institute for Integrated Circuits in Germany, noting that it has even found its niche in medicine.
"Just about every smartphone and notebook today comes with it," he says. Workers at Swedish company Ericsson came up with the standard in 1994. Since 1998, a manufacturer's group calling itself the Bluetooth Special Interest Group has focused on further developing the technology. The name comes from the legendary 10th century Danish king Harald I, who went by the name Bluetooth and was, by all accounts, a good communicator. The modern-day Bluetooth plays a key role in the field of audio transmissions. One popular use is for small, mobile loudspeakers that can be easily set up wirelessly to play music transmitted from a smartphone or tablet. Users mostly enjoy the ease of set-up.
"I don't have to set up or plug in anything. I can just get started," says Holger Wachsmann of the audio industry association High End Society. That compares to other standards, like Apple's Airplay or the universal standard DLNA, which require users to register devices with wi-fi networks or download suitable apps. Bluetooth uses built-in technology. That said, Airplay and DLNA often deliver better sound quality.
But, with the right stereo and audio codec, Bluetooth-transmitted music can sound fine. Codecs like A2DP or aptX, combined with Bluetooth 4.0 can deliver nearly CD quality sounds, says Wachsmann. "Audiophiles might hear differences, but it's not noticeable for laymen." Bluetooth also limits music transmission to a range of about 10 metres, maximum.
"It depends upon where the antenna is inside the loudspeaker and how it's built on," says Wachsmann. Other Bluetooth devices or wi-fi networks can also disrupt connections. Indeed, 10 metres is about the outer limit for most Bluetooth products, though greater distances should be possible with different kinds of Bluetooth. However, further transmission means a lot more energy consumption.
"That's why most manufacturers limit themselves to short distances." Bluetooth frees up a lot of possibilities for mobile devices, like data transfers. But regular use wears batteries down faster. It also makes mobiles more susceptible to viruses, which means it should be shut off when not in use.