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Bluetooth

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Bluetooth is a wireless technology standard used for exchanging data between fixed and mobile devices over short distances using UHF radio waves in the industrial, scientific and medical radio bands, from 2.402 GHz to 2.480   GHz, and building personal area networks (PANs). It was originally conceived as a wireless alternative to RS-232 data cables. Bluetooth is a short-range wireless communication technology standard. Bluetooth is managed by the Bluetooth Special Interest Group (SIG), which has more than 35,000 member companies in the areas of telecommunication, computing, networking, and consumer electronics. The IEEE standardized Bluetooth as IEEE 802.15.1 , but no longer maintains the standard. The Bluetooth SIG oversees development of the specification, manages the qualification program, and protects the trademarks. A manufacturer must meet Bluetooth SIG standards to market it as a Bluetooth device. A network of patents apply to the technology, which are licensed to individual q...

Etymology

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The name “Bluetooth” was proposed in 1997 by Jim Kardach of Intel, who developed a system that would allow mobile phones to communicate with computers. At the time of this proposal, he was reading Frans G. Bengtsson's historical novel The Long Ships about Vikings and the 10th-century Danish King Harald Bluetooth. Bluetooth is the Anglicised version of the Scandinavian Blåtand / Blåtann (or in Old Norse blátǫnn ). It was the epithet of King Harald Bluetooth who united dissonant Danish tribes into a single kingdom, the implication being that Bluetooth unites communication protocols. Logo edit The Bluetooth logo is a bind rune merging the Younger Futhark runes  (ᚼ, Hagall) and  (ᛒ, Bjarkan), Harald's initials.

History

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The development of the "short-link" radio technology, later named Bluetooth, was initiated in 1989 by Nils Rydbeck, CTO at Ericsson Mobile in Lund, Sweden. The purpose was to develop wireless headsets, according to two inventions by Johan Ullman, SE 8902098-6, issued 1989-06-12   and SE 9202239, issued 1992-07-24   . Nils Rydbeck tasked Tord Wingren with specifying and Dutchman Jaap Haartsen and Sven Mattisson with developing. Both were working for Ericsson in Lund. In 1990, Jaap Haartsen was nominated by the European Patent Office for the European Inventor Award. From 1997 Örjan Johansson became the project leader and propelled the technology and standardization. In 1997, Adalio Sanchez, then head of IBM ThinkPad product R&D, approached Nils Rydbeck about collaborating on integrating a mobile phone into a ThinkPad notebook. The two assigned engineers from Ericsson and IBM to study the idea. The conclusion was that power consumption on cellphone technology at that time...

Implementation

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Bluetooth operates at frequencies between 2.402 and 2.480   GHz, or 2.400 and 2.4835   GHz including guard bands 2   MHz wide at the bottom end and 3.5   MHz wide at the top. This is in the globally unlicensed (but not unregulated) industrial, scientific and medical (ISM) 2.4   GHz short-range radio frequency band. Bluetooth uses a radio technology called frequency-hopping spread spectrum. Bluetooth divides transmitted data into packets, and transmits each packet on one of 79 designated Bluetooth channels. Each channel has a bandwidth of 1   MHz. It usually performs 1600   hops per second, with adaptive frequency-hopping (AFH) enabled. Bluetooth Low Energy uses 2   MHz spacing, which accommodates 40 channels. Originally, Gaussian frequency-shift keying (GFSK) modulation was the only modulation scheme available. Since the introduction of Bluetooth 2.0+EDR, π/4-DQPSK (differential quadrature phase-shift keying) and 8-DPSK modulation may also be used between compatible devices. Devices fu...

Uses

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Ranges of Bluetooth devices by class Class Max. permitted power Typ. range (m) (mW) (dBm) 1 100 20 ~100 1.5 (BT 5 Vol 6 Part A Sect 3) 10 10 ~20 2 2.5 4 ~10 3 1 0 ~1 4 0.5 −3 ~0.5 Bluetooth is a standard wire-replacement communications protocol primarily designed for low power consumption, with a short range based on low-cost transceiver microchips in each device. Because the devices use a radio (broadcast) communications system, they do not have to be in visual line of sight of each other; however, a quasi optical wireless path must be viable. Range is power-class-dependent, but effective ranges vary in practice. See the table "Ranges of Bluetooth devices by class". Officially Class 3 radios have a range of up to 1 metre (3 ft), Class 2, most commonly found in mobile devices, 10 metres (33 ft), and Class 1, primarily for industrial use cases,100 metres (300 ft). Bluetooth Marketing qualifies that Class 1 range is in most cases 20–30 metres ...

Computer requirements

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A personal computer that does not have embedded Bluetooth can use a Bluetooth adapter that enables the PC to communicate with Bluetooth devices. While some desktop computers and most recent laptops come with a built-in Bluetooth radio, others require an external adapter, typically in the form of a small USB "dongle." Unlike its predecessor, IrDA, which requires a separate adapter for each device, Bluetooth lets multiple devices communicate with a computer over a single adapter. Operating system implementation edit For Microsoft platforms, Windows XP Service Pack 2 and SP3 releases work natively with Bluetooth v1.1, v2.0 and v2.0+EDR. Previous versions required users to install their Bluetooth adapter's own drivers, which were not directly supported by Microsoft. Microsoft's own Bluetooth dongles (packaged with their Bluetooth computer devices) have no external drivers and thus require at least Windows XP Service Pack 2. Windows Vista RTM/SP1 with the Feature Pack for ...

Specifications and features

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The specifications were formalized by the Bluetooth Special Interest Group (SIG) and formally announced on 20 May 1998. Today it has a membership of over 30,000 companies worldwide. It was established by Ericsson, IBM, Intel, Nokia and Toshiba, and later joined by many other companies. All versions of the Bluetooth standards support downward compatibility. That lets the latest standard cover all older versions. The Bluetooth Core Specification Working Group (CSWG) produces mainly 4 kinds of specifications: The Bluetooth Core Specification, release cycle is typically a few years in between Core Specification Addendum (CSA), release cycle can be as tight as a few times per year Core Specification Supplements (CSS), can be released very quickly Errata (Available with a user account: Errata login) Bluetooth 1.0 and 1.0B edit Versions 1.0 and 1.0B citation needed had many problems, and manufacturers had difficulty making their products interoperable. Versions 1.0 and 1.0B also included ...