A specification to standardize wireless transmission and synchronize data among a wide variety of devices such as PCs, cordless telephones, headsets, printers, and PDAs.The initial effort (April, 1998) was in the form of a consortium of Intel, Microsoft, IBM,Toshiba, Nokia, Ericsson, and Puma Technology and was code-named Bluetooth after Harald Blaatand, the tenth-century Danish king who brought warring tribes together and unified Denmark. Bluetooth is now formalized in IEEE 802.15.1 (2002) as the specification for a wireless personal area network (WPAN) operating in the 2.45 GHz range of the ISM frequency band. Bluetooth employs frequency-hopping spread spectrum (FHSS), with devices stepping through a carefully choreographed pseudorandom hop sequence that makes data collisions highly unlikely even though large numbers of transmissions share the same frequency band. Devices hop through a set of 79 (United States and Europe) or 23 (Spain, France, and Japan) channels spaced 1 MHz apart at a rate of about 1600 hops per second, with each hop lasting 62.5
A man using a Bluetooth headset.
- An example of a Bluetooth device is a cell phone headset.
- An example of a Bluetooth device is a wireless mouse.
The standard wireless personal area network (WPAN) for short-range transmission of digital audio and data. Using radio waves, Bluetooth transmits through walls and other non-metal barriers. Although the term is synonymous with cellphone headsets and in-vehicle, hands-free telephony, Bluetooth is also used for wireless speakers, keyboards, mice, game controllers, smartwatches and more (for category details, see Bluetooth profiles). Spread Spectrum Transmission Using frequency hopping spread spectrum (FHSS), Bluetooth randomly changes to one of 79 channels 1,600 times per second in the same unlicensed 2.4 GHz band as Wi-Fi. See spread spectrum. Bluetooth Versions (see table below) Bluetooth 1.2 (Basic Data Rate) was the first widely used Bluetooth technology. Bluetooth 2.0 + EDR (Enhanced Data Rate) improved speed and interference handling. Bluetooth 3.0 + HS (High Speed) establishes the connection via Bluetooth but transfers data over Wi-Fi. Version 4 added Bluetooth Low Energy (BLE). Branded as "Bluetooth Smart," BLE uses only a quarter of the power at 1 Mbps, and devices can transmit for years on watch batteries (see Bluetooth LE). Scandinavian Origins Named after ancient King Harald Blatan of Denmark, Sweden-based Ericsson developed Bluetooth and co-founded the governing body in 1998 (www.bluetooth.com). Bluetooth is also an IEEE personal area network (PAN) standard (see 802.15). Supporting point-to-point and multipoint architectures (see piconet), there are billions of Bluetooth devices in use. See Bluetooth glossary. BLUETOOTH DATA RATES Max. Data Rate Version (Mbps) 1.2 1 "Bluetooth Classic" 2.0 + EDR 3 "Bluetooth Classic" 2.1 + EDR 3 "Bluetooth Classic" 3.0 + HS 24 (over Wi-Fi) 4.0 3 4.0 + BLE 1 (Bluetooth LE) 4.1 Improvements (see Bluetooth 4.1) 4.2 + BLE 1+ Designed for IoT (see Bluetooth 4.2) BLUETOOTH POWER CLASSES Max. Approx. Power Range Class (mW) (meters) 1 100 100 2 2.5 10 3 1 1