What is Bluetooth?

The art of connecting things is becoming more and more complex every day. In this article, we will look at a method of connecting devices, called Bluetooth that can streamline the process. A Bluetooth connection is wireless and automatic, and it has a number of interesting features that can simplify our daily lives.

What is Bluetooth?

Bluetooth is a way of exchanging data wirelessly over short distances, and is an attempt to do away with your computer’s jungle of wiring.

Using a special radio frequency to transmit data, it creates a short range network. It is very secure and can connect up to eight devices (items of electronic equipment) at the same time. The chip can be plugged into items such as computers, digital cameras, mobile phones and faxes.

Bluetooth is particularly convenient in certain situations – for example, when transferring files from one mobile phone to another without cables. Sending music and photos between a PC and a mobile phone is another useful application.

Why is it called Bluetooth?

The name Bluetooth came from a tenth century Danish King, Harald Blatant or, in English, Harold Bluetooth. As the story goes, King Blatant helped unite warring factions in parts of what are now Norway, Sweden and Denmark. Similarly, Bluetooth technology was created as an open standard to allow connectivity and collaboration between disparate products and industries.

How does Bluetooth work?

Bluetooth sends and receives radio waves in a band of 79 different frequencies (channels) centered on 2.45 GHz, set apart from radio, television, and cellphones, and reserved for use by industrial, scientific, and medical gadgets. Don’t worry: you’re not going to interfere with someone’s life-support machine by using Bluetooth in your home, because the low power of your transmitters won’t carry your signals that far! Bluetooth’s short-range transmitters are one of its biggest plus points. They use virtually no power and, because they don’t travel far, are theoretically more secure than wireless networks that operate over longer ranges, such as Wi-Fi. (In practice, there are some security concerns.)

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.

When a group of two or more Bluetooth devices are sharing information together, they form a kind of ad-hoc, mini computer network called a piconet. Other devices can join or leave an existing piconet at any time. One device (known as the master) acts as the overall controller of the network, while the others (known as slaves) obey its instructions. Two or more separate piconets can also join up and share information forming what’s called a scatternet.

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. Wireless Internet networks are encrypted (use scrambled communications) to get around this problem.

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.

Criminals get more sophisticated all the time; you’ve probably heard about bluebugging (people taking over your Bluetooth device without your knowledge), bluejacking (where people send messages to other people’s devices, often for advertising purposes), and bluesnarfing (downloading information from someone else’s device using a Bluetooth connection) and doubtless there are more ways of hacking into Bluetooth networks still to come. Generally, though, providing you take reasonable and sensible precautions if you use Bluetooth devices in public places, security shouldn’t worry you too much.

How do I use Bluetooth?

You need to check that your device is able to use Bluetooth. You can use a dongle – something which plugs into your computer to enable it to use Bluetooth.

Every manufacturer of compatible devices will have their own instructions for accessing Bluetooth. For detailed instructions you will need to see the manual, but as a general guide:

To set up Bluetooth:

Turn on, or enable, Bluetooth.

Ensure your device is ‘visible’ and not ‘hidden’, so other nearby devices can pick up the signal.

Give your device a name to identify it when connecting to other compatible equipment.

To establish a Bluetooth connection:

Find the file you wish to send.

Select the option to send it via Bluetooth – your device will search for other devices within range and display them.

Scroll to the device you wish to connect with and select it.

If the other device needs ‘pairing’, you will need to enter a passcode – a bit like a PIN number – and make sure it is entered on the other device.

When the connection is established, the data will start to send. You do not need to worry about a clear line of sight between devices.