Bluetooth

Bluetooth is a wireless technology using radio frequencies to share data over a short distance. Bluetooth is often used to pair mobile devices with other mobile or fixed devices, such as headphones, speakers, cars, printers, and computer mouses and eliminates the need for wires. Bluetooth connections typically have a range of up to thirty feet, which can be reduced when obstacles like walls are present.

Bluetooth devices have to be paired before transferring information. The process of pairing devices varies, depending on the devices being connected. Bluetooth connections are generally secure and safe from hacking as they operate on various frequencies, hopping between them hundreds of times per second. This is known as frequency hopping spread spectrum.

Founded in 1998 by Ericsson, IBM, Intel, Nokia, and Toshiba, the Bluetooth Special Interest Group (SIG) has grown into a global community of over 36,000 companies working to unify and drive innovation in Bluetooth technology through shared technical standards.

In 1941, the Austrian-born American actress and inventor Hedy Lamarr and George Antheil filed a patent for a frequency-hopping technology that became a precursor to the secure wi-fi, GPS, and Bluetooth technologies now widely used. Their work aimed to allow radio communications to hop from one frequency to another, such that Allied torpedoes would be undetectable to the Nazis during World War II. While they received no financial compensation for their work, the US military has since publicly acknowledged Lamarr for her frequency-hopping patent and contribution to technology.

Modern Bluetooth was developed by the Swedish telecommunications company Ericsson in the 1990s. In 1993, Dutch engineer Jaap Haartsen began working on indoor wireless communication systems. In 1994, he laid the foundations for the system later known as the Bluetooth Wireless Technology that enabled wireless connectivity between a range of devices.

According to the Centre for Business History in Stockholm, there are roughly ten patents protecting Bluetooth technology, most of which are held by Ericsson. US Patent No. 6590927 titled "Frequency Hopping Piconets in an Uncoordinated Wireless Multi-User System" discloses a wireless network with a master unit capable of communicating with a slave unit by means of a virtual frequency hopping channel. The patent application was filed in September 1997 and issued in July 2003 by the US Patent and Trademark Office. It lists Haartsen as the inventor and Ericsson as the assignee.

Haartsen went on to play an active role in the founding of the Bluetooth SIG and served as chairman for the air protocol specifications group from 1998 until 2000. His work drove the standardization of the Bluetooth radio interface and helped obtain worldwide regulatory approval for Bluetooth technology.

Bluetooth was originally designed to replace RS-232 telecommunication cables using short-range UHF radio waves between 2.4 and 2.485 GHz. While this occupies similar frequencies to wi-fi, Bluetooth was always designed to be a shorter range and lower power alternative. Infrared (used by traditional remote controls) was considered as a wireless option, but it required line-of-sight between devices during data transfer. Using radio signals allowed Bluetooth to provide omnidirectional data transfer.

The RS-232 standard was a widely used computer serial port for:

• internet modems
• printers
• mice
• data storage
• and a host of other peripherals

Bluetooth was designed as a flexible packet-based protocol with a range of profiles to suit these applications and more. It was also designed to use much less power than the RS-232.

Bluetooth is named after Harald "Blåtand" Gormsson, a Viking king who united Denway and Norway, ruling between 958-985. Gormsson was known for his dead tooth with a dark blue/grey shade, giving him his nickname Blåtand which translates from Danish to "Bluetooth." The Bluetooth logo combines the runes of Gormsson's initials ᚼ and ᛒ.

In 1996, short-range radio technology was in its early stages, and there were three competing technologies:

• Biz-RF from Intel
• MC-Link from Ericsson
• Low Power RF from Nokia

In December 1996, representatives from each company met at the Ericsson plant in Lund, Sweden, to plan an industry-standard technology. Intel engineer Jim Kardach suggested that the project's temporary codename be "Bluetooth" while in development.

Kardach explained his reasoning in a blog post:

King Harald Bluetooth ... was famous for uniting Scandinavia just as we intended to unite the PC and cellular industries with a short-range wireless link

Bluetooth was only intended to be a temporary name. Different companies within the SIG developed their own names, with the top two contenders being Radio Wire (the Intel proposal) and PAN (for Personal Area Networking, the IBM proposal). PAN won the vote 4-1 and was chosen as the name of the new technology. However, leading up to the launch event, it was determined PAN was a poor candidate to trademark. While no trademark search had been done for the backup name Radio Wire the only name that could be used on short notice was Bluetooth.

The SIG released the Bluetooth 1.0 specifications in 1999. It was a difficult launch and it looked like the more expensive but faster IEEE 802.11b or Wi-Fi protocol may prevent Bluetooth from finding use. Bluetooth only worked up to a maximum of 30 feet (10 meters), and the technology could only provide transfer speeds up to 721 Kbps. Other issues included anonymity due to compulsory address broadcasting and connection problems.

With slow data transfer speeds, Bluetooth 1.0's main application became wireless Bluetooth headsets for making/receiving phone calls.

The first-ever Bluetooth consumer product was a wireless headset, unveiled in 1999, winning the “Best of Show Technology Award” at COMDEX. The first Bluetooth-enabled phone, the T36, was unveiled by Ericsson in 2000.

Ericsson T39, the first mobile phone with Bluetooth technology.

However, the T36 was eventually canceled, and the first phone with Bluetooth technology available to the public was the Ericsson T39, launched in 2001. The Ericsson T39 utilized Bluetooth 1.0b, a successor to Bluetooth 1.0a. In 2001 IBM introduced the ThinkPad A30 laptop with an in-built Bluetooth connection, and the first Bluetooth car kits became available.

In February 2001, Bluetooth 1.1 was released. While it had the same data transfer rate, it allowed for up to seven simultaneous connections and made it possible for Bluetooth connections on non-encrypted channels.

Bluetooth 1.2 followed in November 2003. It was backward compatible with version 1.1 and improved transfer speeds up to 1 Mbps. Bluetooth 1.2 also introduced:

• Adaptive frequency hopping, making Bluetooth more resistant to radio interference.
• Extended synchronous connections, improving the quality of Bluetooth phone calls offering users an option to increase latency to receive better data transfer for higher quality audio.

By the middle of the 2000s, Bluetooth headsets for mobile phones had found widespread use and the technology was being incorporated into a range of devices, including television sets, wristwatches, sunglasses, picture frames, and many other consumer products.

Bluetooth 2.0 technology became available in 2005. With Enhanced Data Rate (EDR) Bluetooth 2.0 boasted a bit rate of 3 Mbps. However, in real-world use, it was only capable of 2.1Mbps. It allowed for better battery life on devices. Former Executive Director of the Bluetooth SIG Mike Foley stated that a wireless headset operating on Bluetooth 1.2 lasted nintey minutes per charge, compared to over four hours for Bluetooth 2.0. The new standard also improved the maximum range up to 100ft (30m).

Bluetooth 2.1 was released by the SIG in July 2007, offering a simplified process for pairing devices and the option to pair devices using NFC.

Within the first ten years of the protocol, nearly two billion Bluetooth-enabled products were shipped.

Bluetooth 3.0 was adopted by the SIG in April 2009. With its High Speed (HS) channel, version 3.0 could reach data transfer speeds up to 24 Mbps. However, 3.0 used a Bluetooth link to pair devices, and an 802.11 wifi protocol transferred the data.

With improved speeds, Bluetooth 3.0 was the first to move from audio transfer to streaming video.

The SIG formally adopted Bluetooth 4.0, also referred to as Bluetooth Low Energy (BLE), in June 2010. It was initially a project at Nokia under the name Wibree. Bluetooth 4.0 was designed to provide power-efficient connections to smaller wireless devices allowing for battery-operated accessories such as fitness trackers and other smart wearables. The new technology extended the operating range up to 200ft (60m).

The iPhone 4S, released in October 2011, was the first phone to use the new Bluetooth 4.0 protocol.

Bluetooth 5.0 was released in 2016, with the SIG choosing to rebrand it to "Bluetooth 5". It made significant improvements to the maximum range, achieving up to 240m (800 ft) with line of sight and up to 40m (130 ft.) indoors. The new protocol offers significantly faster max data transfer with speeds up to 50 Mbps and the ability to transmit audio to two devices at once, meaning two headphones at once or sending audio to multiple speakers. Bluetooth 5 also focuses on IoT upgrades adding support for better low-energy usage and connection options that use more bandwidth for longer ranges.

Wireless earbuds and headphones allow users to wirelessly connect to devices and listen to audio. In 2019, wireless devices accounted for 76.2% of the earbud and headphone market in terms of revenue. Wireless earbuds and headphones have introduced new features including voice assistance, gesture recognition, fitness tracking, and wearing detection that can play and pause audio.

The first consumer Bluetooth headset was released by Ericsson in 1999. A hands-free mobile headset; it received the "Best of show Technology Award" at COMDEX. Bluetooth technology incorporated into the headset allowed users to make or receive phone calls up to 10 meters away from the phone.

In 2004, the first stereo wireless headphones were released. In the later 2000s, companies such as Bose and Beats began releasing Bluetooth Headphones. The first wireless earbuds were introduced by German company Bragi, but the first devices to gain widespread use were Airpods, released by Apple in 2016.

Other companies selling wireless earbud and headphone products include boAT, Zebronics, Boult Audio, GoNoise, and Portronics.

Bluetooth technology is widely used in home and portable audio equipment, including speakers, soundbars, and subwoofers. Users can connect to audio equipment from a range of devices wirelessly. Bluetooth speakers allow users to keep their devices on hand while listening to audio. Wireless speakers are also simple to operate, take up less space, are convenient for outdoor use, and audio can be streamed to multiple speakers in different rooms or locations.

The global Bluetooth speaker market was valued at $3.4 billion in 2021. With the further integration of technologies such as smart hubs and other IoT products, the Bluetooth speaker market is expected to see significant growth.

Key Bluetooth speaker vendors include Beats, Bose, boAT, Samsung Electronics, Sony, Harman International, Altec Lansing, LG Electronics, Logitech International, Panasonic, and Phillips.

Bluetooth technology is incorporated into wearable devices, typically to connect them to the wearer's smartphone. Among other applications, many of these wearable devices are used to track health and fitness, including to track heart rate, exercise routines, and other health factors.

Bluetooth is widely used to wirelessly connect laptop or desktop computers to devices such as mouses, keyboards, printers, and speakers. Bluetooth can also be used to transfer files between two or more nearby devices (computers, phones, tablets, etc.).

Bluetooth connections allow drivers to connect their phones to the car's control panel for many applications, including answering phone calls, playing music, and for GPS navigation.

Bluetooth technology is seeing increasing integration with IoT devices. Bluetooth's speed, security, and low energy consumption make it an attractive technology for connecting IoT devices. It can also be combined with Radio Direction Finding (RDF) and Received Signal Strength Indicator (RSSI) technologies to provide better locating of devices by tracing direction, and strength of signals.