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Bluetooth

Adapted from Wikipedia · Adventurer experience

A photo of a JBL GO2 Bluetooth speaker being held by a person against a white background.

Bluetooth is a short-range wireless technology used for sharing data between devices like phones, music players, and computers. It works over short distances—usually up to about 10 meters—and uses special radio waves to send information without wires. This makes it perfect for connecting things like wireless headphones, speakers, and car audio systems to your phone or TV.

A Bluetooth earbud, an earphone and microphone that communicates with a cellphone using the Bluetooth protocol

The technology is managed by a group called the Bluetooth Special Interest Group, which includes many companies that make phones, computers, and other electronics. To use the Bluetooth name, a device must meet their standards and get special approval.

Bluetooth has become very common, with billions of devices using it every year. It has even been tested in space, showing how useful it can be for connecting machines in new places.

Etymology

The name "Bluetooth" was created in 1997 by Jim Kardach from Intel. He got the idea from a book about Vikings called The Long Ships, which told stories about a Danish king named Harald Bluetooth. Kardach thought this name would be perfect for the new wireless technology.

Bluetooth is based on the name of King Harald Bluetooth, who brought different Danish tribes together. The logo mixes ancient Viking symbols to show the idea of connecting things. The name was only meant to be temporary, but it became popular for this type of wireless technology.

Logo

The Bluetooth logo mixes two old Viking letters, Hagall and Bjarkan, which are Harald Bluetooth’s initials. This design shows how Bluetooth connects devices together.

History

Ericsson Bluetooth module PBA 313 01/2S R2A, manufactured in week 22 of 2001

Bluetooth technology started in 1989 by Nils Rydbeck at Ericsson Mobile in Lund, Sweden. The idea was to make wireless headsets using ideas from Johan Ullman. A team worked on this, and by 1997, they had a working version.

In 1998, the Bluetooth Special Interest Group (SIG) was created by companies like IBM, Ericsson, Intel, Toshiba, and Nokia to make Bluetooth a standard everyone could use. The first Bluetooth device, a mobile headset, was shown in 1999. The first Bluetooth mobile phone came out in 2001, and laptops with Bluetooth started showing up around that time. Bluetooth became popular as more devices, like cars and home systems, used it to connect without wires.

Implementation

Bluetooth uses radio waves to send data between devices over short distances. It works in a special part of the radio spectrum called the ISM band, between 2.402 GHz and 2.48 GHz. This helps it avoid interfering with other wireless signals.

Bluetooth sends information in small packets, hopping between different channels to reduce interference. It can connect up to seven devices together in a small network called a piconet, where one device acts as the master and talks to the others, which are called slaves. This lets devices like headphones and phones share information easily and reliably.

Uses

A typical Bluetooth mobile phone headset from the early 2000s

Bluetooth is a way for devices to talk to each other without using wires. It uses radio waves, so devices don’t need to be right in front of each other to work. This makes it great for things like connecting a wireless earbud to a phone.

There are many ways people use Bluetooth. You can connect a phone to a car’s speakers, unlock a door with a smartphone, or stream music to wireless speakers. It’s also used in fitness trackers, computer mice, and even some robots. Bluetooth helps devices find each other easily and set up connections automatically, which makes using them simpler and more convenient.

Bluetooth device power by class
ClassMaximum permitted power
mWdBm
110–100+10–+20
1.5*2.5–10+4–+10
21–2.50–+4
30.01–1−20–0
* Class 1.5 included in Class 1 for BR/EDR
Source: Bluetooth Core Specification revision 5.3,
Volume 6, Part A, § 3, and
Volume 2, Part A, § 3, Bluetooth SIG

Computer requirements

An early Bluetooth USB dongle

A personal computer without built-in Bluetooth can use a small device called a Bluetooth adapter to connect with Bluetooth devices. Many modern desktop computers and laptops already have Bluetooth built-in, but older ones may need a USB "dongle" to work with Bluetooth.

Bluetooth is easier to use than older technologies like IrDA because it allows many devices to connect to a computer through a single adapter. Different operating systems support Bluetooth in various ways. For example, Microsoft Windows systems starting from Windows XP Service Pack 2 can work with Bluetooth devices natively. Apple Mac computers have supported Bluetooth since Mac OS X v10.2. Linux systems use Bluetooth stacks such as BlueZ or Fluoride to enable Bluetooth connections. Other operating systems like FreeBSD, NetBSD, and DragonFly BSD also include Bluetooth support through different implementations.

Specifications and features

Bluetooth technology was created by a group of companies and started in 1998. It helps devices talk to each other over short distances without wires. Many devices, like headphones and computers, use Bluetooth to connect.

Bluetooth has changed a lot since it began. Each new version makes it better to send information, safer, and uses less power. This makes Bluetooth useful for many things, from connecting speakers to helping health trackers work better.

Bluetooth versions
VersionAdoption yearMaximum rateMax rangeRadio frequency
MajorMinorClassicLow Energy
11.01999732.2 kbit/s—N/a10 m2.4 GHz
1.12001
1.220031 Mbit/s
22.020042.1 Mbit/s
2.12007
33.02009
44.020091 Mbit/s60 m
4.12013
4.22014
55.020162 Mbit/s240 m
5.12019
5.22020
5.32021
5.42023
66.020243 Mbit/s300 m
6.12025???
6.2???

Technical information

Bluetooth devices use a special interface called HCI (Host Controller Interface) to work together. They have protocols like SDP (to find other devices), RFCOMM (to act like a wire), and TCS (for phone control). These talk to a main controller using L2CAP, which handles data packets.

Bluetooth devices have two main parts: a radio for sending signals and a digital controller that runs software. They are made on tiny chips and can talk to each other over short distances. The Link Manager helps devices connect, check each other, and set up links.

Bluetooth devices can find each other and share information, but they often need to be “paired” first. Pairing creates a secure link so only trusted devices can connect. This helps keep data private and stops unauthorized access.

Security

Bluetooth uses special methods to keep information safe and make sure only the right devices can connect. When two Bluetooth devices first connect, they often need a special code, called a PIN, to match before they can talk to each other. This helps stop others from sneaking into your devices.

Over the years, some problems with Bluetooth security have been found. For example, some older ways of connecting devices could be tricked. Experts have worked to fix these issues, and most new devices now use stronger ways to keep information safe. It’s important for users to keep their devices updated to stay safe.

Health concerns

Main article: Wireless device radiation and health

Bluetooth devices use radio waves. These radio waves are a type of non-ionizing radiation, like the kind used by wireless and mobile phones. Scientists have not found any specific harm from Bluetooth. Some groups have listed wireless transmission as a possible carcinogen. Bluetooth devices have different power levels. The strongest Bluetooth device is 100 mW. This is still less powerful than even the lowest-powered mobile phones. Other mobile phones can have much higher power.

Award programs

The Bluetooth Innovation World Cup was a contest to find new ways to use Bluetooth in sports, fitness, and health care. It wanted to help make new markets for Bluetooth products.

In 2013, the contest became the Bluetooth Breakthrough Awards. In 2016, the Bluetooth SIG started the Imagine Blue Award at Bluetooth World. The Bluetooth Breakthrough Awards honor the best new products, early prototypes, and student projects that use Bluetooth technology.

Images

A small Bluetooth card for laptops made by DELL, used to connect devices wirelessly.

Related articles

This article is a child-friendly adaptation of the Wikipedia article on Bluetooth, available under CC BY-SA 4.0.

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