Bluetooth

Bluetooth is a wireless communication system used for small or handheld devices. It allows nearby devices to communicate quickly and efficiently on a private network. Bluetooth is commonly used with phones, headsets, keyboards, and speakers. It works best when devices remain in close proximity and is convenient for situations in which wired connections would be troublesome.

History of Bluetooth

Bluetooth’s origins can be traced to the frequency-hopping spread spectrum (FHSS) technique patented in 1942. FHSS was originally designed as a mechanism for controlling a torpedo through radio signal in a way that the frequency could not be jammed. The idea of a radio signal that consistently jumps between frequencies is essential to Bluetooth communications.

In the early 1990s, several telecommunications companies, including Nokia, Ericsson, Intel, Toshiba, and IBM, wanted to develop a form of wireless communication between cellular phones and computer devices. However, they understood that for this form of communication to be commercially successful, it would have to work with devices running on all network providers. For this reason, the companies decided to form a special interest group (SIG) to further this development. The SIG was finalized in 1998, and the first Bluetooth technology was developed in 1999.

The name "Bluetooth" was coined by an ancient Danish king, Harald Blatand, who forcibly united the surrounding Danish tribes for a common goal. The SIG thought the name was appropriate for a technology uniting all the major technology firms of the time. Bluetooth was meant to be a temporary moniker and was supposed to be replaced as soon as the marketing team found a better label for the new technology. However, the name stuck, and soon it was easier to continue referring to the devices as Bluetooth transmitters. The Bluetooth symbol found on most Bluetooth enabled devices was created from the runic initials of King Blatand.

The SIG continued to invest, develop, and attract new members. It was shipping millions of functioning units per week by 2005. Two years later, with the acquisition of the Wibree Alliance, the SIG gained access to new technology that drastically reduced the amount of power necessary for a Bluetooth device to function. This allowed Bluetooth devices to run on miniscule, common, coin-cell batteries.

Low-power Bluetooth devices were improved and finalized by 2024, with the release of Bluetooth 5.4. In 2023, more than five billion Bluetooth devices are shipped annually, according to Statista. These devices are used in large numbers of cell phones, headphones, microphones, speakers, clocks, keyboards, computer mice, tablets, printers, and computers.

How Bluetooth Works

Bluetooth devices operate in the same transmission frequency range as Wi-Fi Internet and microwaves, constantly jumping between frequencies to avoid interference from other devices. A Bluetooth device contains both a receiver and transmitter, which are operating as long as the device is turned on. These devices form a master-slave style network. These networks contain one controlling device, called the master device, and up to seven actively controlled devices, called slave devices. Networks containing one master device with the potential for up to seven slave devices are called piconets. Bluetooth-enabled devices may belong to multiple piconets at a time, as either a master device or a slave device. Piconets may also contain many more slave devices, on the condition that only seven or fewer slave devices are operating on the network. An example piconet could include one smartphone as the master device, with a Bluetooth headset and a car stereo as slave devices.

In order to form a piconet, slave devices need to synchronize with a master device. While this process may be accomplished via a wire in traditional networking, Bluetooth devices use a system of inquiry and inquiry scan. Potential slave devices constantly emit an inquiry signal. This is a signal that identifies the device, its basic purpose, and whether the device is already paired to a master device. Master devices then preform inquiry scans, which involve scanning all known frequencies used by Bluetooth devices for inquiries. The two devices then exchange information, and the master device displays this information to its user, with the option to allow the devices to further interact. If the user allows the interaction, the devices are paired.

For example, a smartphone user wants to pair his smartphone with a wireless Bluetooth headset. The headset, a slave device, is broadcasting its inquiry at all times. The user tells the smartphone to scan for new devices, and the smartphone’s inquiry scan finds several nearby devices. One of these is identified as a Bluetooth headset. The user then pairs the smartphone with the headset, allowing the two to function together.

Alternatives to Bluetooth

While Bluetooth once dominated the market for short-range wireless electronic communication, several competing technologies developed. The most prominent of these are near field communication (NFC) and Wi-Fi Direct. NFC allows two devices to communicate at an extremely fast rate. However, it requires the two devices to be within inches of each other. For this reason, NFC is often used as a method of secure, wireless payment. Credit card or bank account information stored on a smartphone or other mobile device simply needs to be held up to a corresponding terminal for payment to be processed. This limited short-range communication, however, means that NFC can never truly replace Bluetooth.

Wi-Fi Direct is more similar to Bluetooth than NFC and is considered more of a threat to Bluetooth’s market share. Devices enabled with Wi-Fi Direct can wirelessly communicate with each other in areas that lack a traditional Wi-Fi network. They can also communicate with most Wi-Fi enabled devices, just as if a traditional Wi-Fi network were in place. Most importantly, Wi-Fi Direct allows data to transfer ten times faster than Bluetooth.

Bibliography

"How Does Bluetooth Work?" Scientific American. Nature America, Inc. Web. 5 Feb. 2016. http://www.scientificamerican.com/article/experts-how-does-bluetooth-work/. Accessed 13 Jan. 2025.

"Quick History of Bluetooth." Packetcraft, 24 Oct. 2023, https://www.packetcraft.com/post/quick-history-of-bluetooth. Accessed 13 Jan. 2025.

Rogerson, James. "Bluetooth: What Does It Really Do and Will It Be Replaced?" TechRadar. Future US, Inc. Web. 5 Feb. 2016. http://www.techradar.com/us/news/phone-and-communications/mobile-phones/what-is-bluetooth-how-it-works-and-how-you-can-use-it-1141428. Accessed 13 Jan. 2025.