Bluetooth has become an indispensable component of modern smartphones.
Intended primarily to connect a device with wireless peripherals, its uses have expanded to areas as diverse as data distribution and smart home security.
In this beginner’s guide to Bluetooth, we explain how the technology works, its primary use cases, and why it’s become so important to Apple customers in particular.
Blue is the colour
Like many modern technologies, Bluetooth’s origins extend back to the febrile days of the late 1990s.
This short-link radio technology was developed by Swedish mobile phone manufacturer Ericsson, initially as a way of powering other devices
Following an award-winning launch at the predecessor of the Consumer Electronics Show in Las Vegas in 1999, Bluetooth debuted in 2001’s Ericsson T39 phone.
It provided wireless communication across a range of less than 33 feet (ten metres), at a time when WiFi was still in its infancy and NFC couldn’t achieve sufficient range to be practical.
Known as a wire-replacement communications protocol, Bluetooth has been designed to minimise power consumption by using radio communications, with no line-of-sight needed.
How does it work?
Any beginner’s guide to Bluetooth has to acknowledge the rather unfortunate choice of frequency for distributing wireless signals between one device and another.
Bluetooth runs across the congested 2.4GHz frequency – also home to car alarms, home broadband systems, baby monitors and more.
Information is broken down into individual packets, much like internet data, before being distributed across one of 79 distinct 1MHz Bluetooth channels.
Unlike some wireless connections which are based on a relationship of equals, Bluetooth relies on a master-and-slave connection between a device and up to seven subordinates.
This reflects the largely one-way nature of Bluetooth communications – music sent to wireless headphones, or an image file shared from device A to device B.
In the case of smart devices like laptops and smartphones, they can be master or slave, depending on whether they’re connecting to something or being connected to.
What is Bluetooth used for?
The primary use of Bluetooth is to connect a wireless peripheral to a computer or mobile device, such as using cordless headphones with a smartphone.
It’s grown in popularity after Apple dropped the 3.5mm jack from its iPhone range, forcing people to use an adaptor in the charging slot or invest in wireless headphones.
Wireless Bluetooth speakers are also growing in popularity, eliminating cables snaking across rooms or gardens.
Other popular uses of Bluetooth include linking a phone to a car’s infotainment system to support hands-free calling and messaging.
It can be used to support cordless computer peripherals like keyboards and mice, or even share files between a computer and a smartphone (or vice versa).
As the Internet of Things expands, Bluetooth is being deployed to unlock doors on approach, and track the presence of sensitive items in proximity to a handset or computer.