Bluetooth Overview
– Etymology
– Bluetooth was proposed as a codename for the short-range wireless program.
– The name Bluetooth was inspired by the Danish king Harald Bluetooth.
– The name was chosen to imply the unification of communication protocols.
– The official name was intended to be RadioWire or PAN, but they were not available.
– The Bluetooth logo merges the Younger Futhark runes for Harald’s initials.
– History
– The development of Bluetooth started in 1989 by Nils Rydbeck at Ericsson Mobile.
– The purpose was to develop wireless headsets.
– The project began in 1994 and had a workable solution by 1997.
– IBM and Ericsson collaborated to integrate Bluetooth into a ThinkPad notebook and phone.
– The Bluetooth SIG was launched in 1998 with founding signatories IBM and Ericsson.

Bluetooth Implementation
– Frequency and Technology
– Bluetooth operates at frequencies between 2.402 and 2.480GHz.
– It uses frequency-hopping spread spectrum technology.
– Data is divided into packets and transmitted on 79 designated Bluetooth channels.
– Each channel has a bandwidth of 1MHz.
– Bluetooth Low Energy uses 2MHz spacing and accommodates 40 channels.

Uses of Bluetooth
– General Uses
– Bluetooth is used for exchanging data between fixed and mobile devices.
– It enables file exchange between portable devices and connects cell phones with wireless headphones.
– It is an alternative to wire connections.
– Bluetooth is used in personal area networks (PANs).
– It is widely used in telecommunication, computing, networking, and consumer electronics.
– Statistics
– The Bluetooth Special Interest Group (SIG) has over 35,000 member companies.
– Bluetooth is managed by the Bluetooth SIG.
– A manufacturer must meet Bluetooth SIG standards to market a Bluetooth device.
– There is a network of patents that apply to Bluetooth technology.
– As of 2021, 4.7 billion Bluetooth integrated circuit chips are shipped annually.

Bluetooth Modulation and Communication
– Modulation Schemes
– Frequency-shift keying (GFSK) modulation is the original modulation scheme used in Bluetooth.
– Bluetooth 2.0+EDR introduced π/4-DQPSK and 8-DPSK modulation schemes.
– GFSK operates in basic rate (BR) mode with a bit rate of 1Mbit/s.
– Enhanced Data Rate (EDR) modes provide higher bit rates of 2Mbit/s and 3Mbit/s.
– Communication and Connection
– A master Bluetooth device can communicate with up to seven devices in a piconet.
– Devices can switch roles, allowing a slave to become a master.
– The Bluetooth Core Specification allows for the formation of scatternets.
– Data can be transferred between the master and one other device at a time.
– The master chooses which slave device to address, while a slave is supposed to listen in each receive slot.

Bluetooth Profiles and Applications
– Profiles and Applications
– Bluetooth profiles define specific behaviors for Bluetooth-enabled devices to communicate with each other.
– Examples of Bluetooth profiles include the Headset Profile (HSP), Health Device Profile (HDP), and Video Distribution Profile (VDP).
– Adherence to profiles saves time by transmitting parameters before establishing a bi-directional link.
– Bluetooth technology is used in various applications, including wireless control of audio and communication functions, smart locks, fitness devices, and PC networking.
– Applications of Bluetooth
– Test equipment, GPS receivers, medical equipment, bar code scanners, traffic control devices.
– Bluetooth vs Wi-Fi (IEEE 802.11)
– Bluetooth is intended for portable equipment and wireless personal area network (WPAN) applications.
– Wi-Fi is a replacement for high-speed cabling in local area network (LAN) access.
– Wi-Fi is access point-centered, while Bluetooth is usually symmetrical between two devices.
– Bluetooth serves well in simple applications with minimal configuration, like headsets and speakers.
– Wi-Fi and Bluetooth are complementary in their applications and usage.Sources: