What is Bluetooth? Technology Explained!

Almost every device you can buy today supports Bluetooth, but what is Bluetooth? Simply put, Bluetooth is a way for two nearby gadgets to transmit data to each other.

Let’s take a look at what Bluetooth is, trace its roots, discuss its pros and cons, and find out how it differs from other common wireless technologies like Wi-Fi or NFC.

The “Bluetooth” name is taken from a 10th-century Danish king named Harald Bluetooth, who was said to unite disparate, warring regional factions. Like its namesake, Bluetooth technology brings together a broad range of devices across many different industries through a unifying communication standard.

Bluetooth uses less power and costs less to implement than Wi-Fi. Its lower power also makes it far less prone to suffering from or causing interference with other wireless devices in the same 2.4GHz radio band.

The Bluetooth 4.0 specification was officially adopted on July 6, 2010. Bluetooth version 4.0 features include low energy consumption, low cost, multivendor interoperability, and enhanced range.

The hallmark feature enhancement to the Bluetooth 4.0 spec is its lower power requirements; devices using Bluetooth v4.0 are optimized for low battery operation and can run off of small coin-cell batteries, opening up new opportunities for wireless technology. Instead of fearing that leaving Bluetooth on will drain your cell phone’s battery, for example, you can leave a Bluetooth v4.0 mobile phone connected all the time to your other Bluetooth accessories.

No one “owns” Bluetooth, but its use and advancement is managed by an entity.

To ensure Bluetooth became a universal communications protocol, in 1998 a group of companies came together to form the Bluetooth Special Interest Group (SIG), a not-for-profit group.

What makes Bluetooth different is the use of a technique called frequency hopping. It’s a bit technical, but there’s a simple explanation. Bluetooth uses 79 bands of radio waves in the aforementioned 2.4GHz frequency. When you send data, Bluetooth first divides this data into smaller packets. These packets are sent individually over those 79 bands, and Bluetooth is smart enough to change bands rapidly so that no one line gets clogged.

That’s the main platform of the technology. With the smart “hopping” of data transfers, Bluetooth can simultaneously connect up to eight devices and allow them to talk to each other.

When Bluetooth connects two devices, it forms something called a Personal Area Network (PAN). PAN does not require an internet connection or mobile service to transfer files or anything else.

Bluetooth devices automatically detect and connect to one another and up to eight of them can communicate at any one time. They don’t interfere with one another because each pair of devices uses a different one of the 79 available channels. If two devices want to talk, they pick a channel randomly and, if that’s already taken, randomly switch to one of the others (a technique known as spread-spectrum frequency hopping).

To minimize the risks of interference from other electrical appliances (and also to improve security), pairs of devices constantly shift the frequency they’re using—thousands of times a second.

Radios are clever electronic gadgets, so why can’t they do this neat trick for themselves? Why can’t they simply switch to another frequency automatically to prevent interference and eavesdropping? This is the basic idea behind a technique called spread-spectrum frequency hopping, where signals are rapidly and randomly switched across a wide range of different frequencies to improve the security and reliability of wireless communication.

Is Bluetooth better or worse than Wi-Fi?

People often get confused by Bluetooth and Wi-Fi because, at first sight, they seem to do similar things. In fact, they’re very different. Bluetooth is mainly used for linking computers and electronic devices in an ad-hoc way over very short distances, often for only brief or occasional communication using relatively small amounts of data. It’s relatively secure, uses little power, connects automatically, and in theory presents little or no health risk.

Wi-Fi is designed to shuttle much larger amounts of data between computers and the Internet, often over much greater distances. It can involve more elaborate security and it generally uses much higher power, so arguably presents a slightly greater health risk if used for long periods.

Bluetooth and Wi-Fi are complementary technologies, not rivals, and you can easily use both together to make your electronic gadgets work more conveniently for you!

Is Bluetooth secure?

Wireless is always less secure than wired communication. Remember how old spy films used to show secret agents tapping into telephone wires to overhear people’s conversations? Cracking wired communication is relatively difficult.

Eavesdropping on wireless is obviously much easier because information is zapping back and forth through the open air. All you have to do is be in range of a wireless transmitter to pick up its signals.

How secure is Bluetooth? Like Wi-Fi, communications are encrypted too and there are numerous other security features.

You can restrict certain devices so they can talk only to certain other, trusted devices—for example, allowing your cellphone to be operated only by your Bluetooth hands-free headset and no-one else’s. This is called device-level security. You can also restrict the things that different Bluetooth gadgets can do with other devices using what’s called service-level security.

How is Bluetooth evolving?

Bluetooth has often been quite tricky to use: like any wireless technology, it’s another battery drainer for mobile devices; you can often step out of range, making communication erratic or impossible; and even getting two Bluetooth devices to talk to one another in the first place isn’t always as simple as it should be.

The world of mobile devices is changing as we move toward the so-called Internet of things (where all kinds of everyday objects become net-connected)—and Bluetooth has to keep evolving to keep up.