Bluetooth: Everything You Need To Know

Zach Scheepers | July 19, 2019 12:36 pm

What is Bluetooth?

Bluetooth is what allows you to connect your smartwatch to your smartphone. It’s a short-distance wireless connection between 2 or more devices (known as pairing) that allows you to transfer data wirelessly rather than through a cable. To use this technology, your devices must be Bluetooth-enabled. Bluetooth has become an industry standard, with almost all portable speakers and wireless headphones featuring Bluetooth. In this guide, we’ll cover all of the questions you might have surrounding Bluetooth and how to connect your devices.

The History of Bluetooth

Bluetooth was first developed as a “short-link” radio technology and was initiated in 1989 by Nils Rydbeck and Johan Ullman. The purpose was originally to develop wireless headsets. The first consumer Bluetooth device was a hand-free mobile headset launched in 1999, and later, the first Bluetooth mobile phone was the Ericsson T39, which was available in stores in 2001. Nowadays, Bluetooth is a wireless technology used to exchange data between fixed and mobile devices over a short distance using UHF radio waves and building personal area networks.

Bluetooth is currently managed by the Bluetooth Special Interest Group (SIG), which has more than 30,000 members in fields of computing, networking, telecommunication, and consumer electronics. SIG oversees the development of the specification, controls the qualification program, and protects the trademarks. A manufacturer would need to meet Bluetooth SIG standards to market a Bluetooth device. The purpose of Bluetooth is, therefore, to replace the cables we use to connect devices while keeping communications between them secure.

The term “Bluetooth” was derived from a 10th-century Danish King named Harald Bluetooth, who is said to have united different factions at war. Like Harald Bluetooth, Bluetooth technology brings together various devices across many industries through a unifying communication standard. The idea of the name was proposed by Jim Kardach of Intel in 1997, who at the time was reading Frans G. Bengtsson’s historical novel ‘The Long Ships’ about Kind Harald Bluetooth and Vikings. The logo is a bind rune merging from the Younger Futhark runes ‘Hagall’ and ‘Bjarkan,’ King Harald’s Bluetooth initials.

The History of Bluetooth - Outeraudio

How Does Bluetooth Work?

Bluetooth sends and receives radio waves in a band of 79 different frequencies (also known as channels) focussed on 2.45 GHz; these frequencies are reserved for scientific, industrial, and medical gadgets, so don’t worry; you will not interfere with someone’s life-support. These radio waves use virtually no power, and because they don’t travel as far, they are considered more secure than wireless networks that operate over longer ranges, for example, Wi-Fi.

Bluetooth devices automatically connect and eight can communicate at any one time. These devices will not interfere with one another because each pair uses a different channel available on the 79 frequencies. To explain it in clearer terms, a technique known as spread-spectrum frequency hopping states that if two devices want to connect, they pick a channel randomly. If this channel is already in use, the devices will switch to another available one. Pairs of devices will also shift the frequency they use thousands of times a second to minimize the risk of interference from other electrical appliances.

When two or more Bluetooth devices are connected and sharing information together, they form a mini-computer network called a piconet. Other devices can then join or leave an existing piconet at any time. One device, known as the ‘master’ controls the network, while the others known as ‘slaves’ obey its instructions. When two or more separate piconets join and share information, this is called a scatternet.

How Does Bluetooth Work with Headsets?

The easiest way to explain how Bluetooth works is by constantly transferring data and audio from a paired Bluetooth transmitter to a paired receiver. Paring is the bonding procedure between Bluetooth devices, so you don’t have to re-enter security information like passwords every time the devices need to establish a connection. This will be discussed in greater detail under ‘Bluetooth Headphones.’

Once a secure connection is established between a transmitter and a receiver, data is distributed into small packets, which are then transferred at alternating frequencies (2.402-2.480GHz). The different types of profiles and versions of Bluetooth may vary, but the core foundation remains the same. To avoid interference with other devices that may also use industrial, science, and medical bandwidth of 2.4 GHz, Bluetooth-enabled devices will randomly jump between frequencies 1600 times per second until all packets of data are transferred.

Connecting with Bluetooth

Most mobile devices have Bluetooth radios embedded in them. However, PCs and other devices that do not have built-in radios can be Bluetooth-enabled by plugging in a dongle. Pairing is a process whereby two Bluetooth devices are connected. In most cases, devices broadcast their presence to each other, and the users select which Bluetooth device they want to connect to when the other device’s name or ID appears on their screen—with the increase in Bluetooth technology, knowing when and which device you’re connecting to is important. Therefore, a code is usually prompted on-screen that helps to ensure you are connecting to the right device.

Different devices have their instructions for accessing and using Bluetooth. For detailed instructions, be sure to check the manual of your product, but as a general guide, the following instructions might provide some clarity:

To Set Up Bluetooth:

  1. Turn on or enable Bluetooth. Dragging down the settings can usually be done on your phone’s front screen.
  2. Always ensure your device is ‘visible’ so other nearby devices can pick up the signal. A default setting of ‘hidden’ may prevent your device from being picked up.
  3. Give your Bluetooth device a custom name so it is easy to identify when connecting to other compatible equipment.

To Establish a Bluetooth Connection:

  1. Select the file you wish to send. This may be an audio file, picture, document, or anything that is transferrable.
  2. Select the option to send via Bluetooth. Most smartphones require you to hold down on the file until the options menu appears and Bluetooth is available. Your device should then search for other devices within range and display them.
  3. When different devices are now in range, scroll to the correct device you wish to connect with and select it.
  4. The other device may need to ‘pair.’ In such cases, the other device must enter the same password displayed on your screen.
  5. Once a connection is established, the data will start to send. A clear line of sight is not needed between devices.
  6. Finally, turn off your Bluetooth once you have finished sending the files you want. This will prevent other people from accidentally trying to pair to your device or seeing it as an available option.

Bluetooth headphones

Bluetooth headphones are one of the most common accessories and uses of Bluetooth technology. Having a Bluetooth headset with your phone or device allows you to make and receive calls without holding your phone or listening to music without the hassle of cables getting in the way. If your device has Bluetooth support, pairing a Bluetooth headset is easy and convenient. Unlike pairing with another smartphone, most headsets don’t have a ‘screen’ and require a different method to connect.

The following is a step-by-step process on how to connect Bluetooth headphones or how to pair Bluetooth headphones:

  1. Charge your headset and device: A full battery on both headset and smartphone will ensure the process won’t be interrupted by a low battery.
  2. Pairing mode: Your headset ‘pairing mode’ is a process that is similar to almost all Bluetooth headsets, some variations may exist across different brands but the process is ideally the same. Start with the headset power off, then press and hold the multi-function button for a few seconds. A light should blink showing the unit is now on, keep holding this button and after a few seconds, the LED will blink different colors. These blinking lights indicate that the headset is now in pairing mode.
  3. Put your headset next to your device: If you are using a smartphone, the headset and phone will need to be close to one another in order to pair. Distances may vary but a general rule is to keep the devices within 5 feet of one another for the best results.
  4. Start Bluetooth on your phone: Most phones released after 2007 are Bluetooth enabled. If you’re using an iPhone, Bluetooth will be found in the settings menu. If it says “off” next to Bluetooth, tap it to turn it on. Android users will also find Bluetooth in the app menu, and should enable it by tapping “on.”
  5. Scan for Bluetooth devices: Your Bluetooth is now on and it is time to scan for other devices. Bluetooth should automatically begin to search for other devices and a list of available options should appear on the screen.
  6. Select the headset for pairing: In the list of connectable Bluetooth devices, the name of your headset should appear, for example, ‘SONY-HEADSET.’ Tap on the headsets name to pair the device. The name of the device will usually be the manufacturer’s name or it may be listed as ‘headset.’
  7. Enter PIN code, if required: Sometimes a PIN code may be required to pair the devices. This may prompt on the screen once the smartphone has found the headset. The code for the headset might be the last 4 digits of your headsets serial number, or something simple like “0000, 1234 or 4444.” These codes may also be in the headset user manual. If no code is required, your smartphone will connect automatically.
  8. Select “Pair”: Once the headset and phone are connected, you should see a confirmation message on the phone stating “connection establish” or something along those lines.
  9. Ready for use: The headset and smartphone should now be ready for listening to music or making calls.

When used with precautions, Bluetooth is considered a reasonably secure wireless technology. Connections are encrypted, which prevents casual eavesdropping from devices nearby. Bluetooth devices also change radio frequencies when connected to prevent easy invasion. A variety of settings are offered by Bluetooth devices, which allow the user to limit connections. A “trusting” security level restricts connections to only specific devices, whereas a service-level security setting restricts the different kinds of activities your device is allowed to engage in while on a Bluetooth connection.

Like any wireless technology, there is always some security risk involved and hackers have devised numerous ways to maliciously attack information using Bluetooth networking. Examples can be “Bluesnarfing” where a hacker gains authorized access to information on a device through Bluetooth or “bluebugging” where a hacker resumes control over your smartphone and all its functions.

Bluetooth doesn’t pose much risk for the average person when used with safety precautions. For example not connecting to unknown devices or receiving files from strangers. To keep yourself protected always disable your Bluetooth in public unless you are certain the prospective paired device is indeed the one you intend to share information with.

Limitations of Bluetooth

Bluetooth offers a wide range of benefits when it comes to the sharing of information, but like anything, there are some drawbacks. Firstly, Bluetooth can drain the power of your battery for wireless devices like smartphones. Improvements have been made and the problem isn’t as significant as the past, but it still affects your battery. The range is also fairly limited, usually extending to 30 feet, and like other wireless technologies, obstacles such as walls and ceilings may reduce this even further. Finally, the pairing process can sometimes be difficult and frustrating. Depending on the devices being used or the manufacturers, problems can arise when attempting to connect. Following instructs perfectly can still result in no connection, so the connectivity hasn’t been perfected yet for all platforms and manufacturers.

Difference Between Bluetooth and WIFI

Bluetooth vs Wifi Infographic - Outeraudio

Bluetooth and WIFI are both methods that provide wireless communication, the difference between the two are found in what they are designed to do, and how they are used. The main difference is that Bluetooth is used to connect or pair with devices without using cables, whereas WIFI provides access to the internet.

As stated earlier, Bluetooth is used to exchange data over short distances, approximately 30 feet. This means that Bluetooth-enabled devices such as smartphones are able to connect with other Bluetooth devices, such as a printer or wireless headset. Bluetooth acts like a wired cord between the two creating a wireless personal area network in which these devices can exchange information. Bluetooth has a variety of applications and the convenience and functionality of portable devices by providing a simple way for them to interact with other Bluetooth devices.

In contrast, WIFI has similar applications to Bluetooth, for example, transferring files, printing, or setting up a network. Like Bluetooth, WIFI is also a wireless standard, but instead of being designed to communicate between devices, it serves to wirelessly connect devices to the internet or Ethernet networks. WIFI, therefore, shuttles much larger amounts of data between computers and the internet. Its range is much larger than Bluetooth, as Wi-Fi signal can be accessed from up to 300 feet away.

The result is that a WIFI-enabled device, such as a smartphone or computer, can connect to the internet wirelessly when in a “hotspot” area. The hotspot area may be as small as a bedroom or cover several miles if the hotspots are allowed to overlap. WIFI involves more intricate security and generally uses higher amounts of power, so it arguably presents a greater health risk if used for extended periods. In conclusion, it is available in many devices, and hotspots continue to flourish across airports, shopping malls, university campuses, and other public areas.

Overall, WIFI and Bluetooth are complementary technologies that provide different uses and functions. They should not be viewed or compared as rivals to one another. Both can be used together to make your WIFI and Bluetooth-enable devices work more conveniently and your life that much easier.

Bluetooth Versions Comparison

Bluetooth is the most common wireless communication technology available for smartphones and headsets. Throughout the years it has progressively improved with newer iterations, being able to support more profiles and features. The version of Bluetooth your devices come equipped with will determine the speed of file transfer. Regarding Bluetooth speakers or headsets, it can determine the quality of the audio and the distance you can keep between your smartphone and device. Bluetooth 4 or better supports battery life with low energy profiles of up to 60m. Bluetooth 5 is currently the latest version, but it will be some time before this becomes standard in most devices.

The following table illustrates the different versions and their capabilities:

Bluetooth 1.0

Bluetooth version 1 came equipped with the basic Bluetooth rate (BR) and had no additional profiles or codecs. It was rarely implemented into smartphones due to its slow speed of 1 Mbps and difficulty with pairing devices.

Bluetooth 2.0

Version 2 was considered the most popular variant of Bluetooth, especially a few years ago when phones were not as advanced as they are today. Version 2 supports enhanced data rates (EDR) of up to 3 Mbps, and significantly simplified pairing which made it more practical for commercial use.

Bluetooth 3.0

Bluetooth version 3 featured optional High-Speed (HS), which allowed Bluetooth module to transmit over an adjacent radio (802.11). It therefore significantly improved upon the speed limitations of version 2 but consumed a lot more power.

Bluetooth 4.0

Bluetooth 4 took advantage of Bluetooth 3 with high-speed capability but also offered a Low Energy (LE) feature, allowing the Bluetooth module to reduce power consumption with devices like smartphones, headphones, heart monitors, and smartwatches.

Bluetooth 5.0

The latest version of Bluetooth is suited for the Internet of Things (IoT). It allegedly has twice the bandwidth of Bluetooth 4.2 and four times the range. Its newest feature, ‘Slot Availability Masking’ (SAM) can detect and stop interference on neighboring bands for more proficient use of broadcasting channels.

Bluetooth Profile

As stated previously, as Bluetooth becomes more advanced, more features and profiles will appear. There are a lot of Bluetooth profiles available. However, the following are listed with relevance to Bluetooth headphones:

Headset Profile:

This profile is considered basic headset functionality and allows for microphone input and 64 kbps mono audio.

Handsfree Profile:

This profile is regarded as advanced headset functionality and adds more controls to the ‘Headset Profile’ such as redialling, voice dialing, and better audio quality.

Advanced Audio Distribution Profile:

The A2DP profile features stereo audio transmission, the most important profile for Bluetooth headphones, as mono audio is unsuitable for listening to music.

Audio and Video Remote Control Profile:

AVRCP gives you control of media playback, such as play/pause, volume control, and skipping tracks. The latest version of AVRCP gives you direct control over your device’s volume, in contrast to only being able to adjust the headset/headphones.

It should be mentioned that codecs are the encoding and decoding algorithms that compress data into packets for quick and more reliable transmission. For wireless headsets, there are a few codecs to improve both latency and sound quality. The three main codecs that users are familiar with are Advanced Audio Coding, Subband Coding, and aptX.

Bluetooth is also backward compatible, so you don’t need to worry about the different versions, profiles, and codes. However, having the necessary profile will be essential if you use your headphones a lot to make calls or control media playback. If you watch movies or play many video games with your headset, then having additional low-latency codecs will certainly improve your experience. But for just listening to audio, any Bluetooth headset should be appropriate, so your choice of headset should depend more on its sound quality and your preference in what you expect it to do.


Bluetooth is a wireless technology aimed at exchanging data wirelessly over short distances and is an attempt to remove the wiring from your life and add convenience. Using a special radio frequency, it creates a short-range network that securely transmits data and allows you to listen to audio. Bluetooth developers are constantly recognizing the need to connect an increasing range of devices more quickly and securely, and thus, improved versions are being created regularly with infinite possibilities for future profiles and features.

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Author: Zach Scheepers

Based in South Africa, Zach is an audiophile and PC enthusiast. Zach is skilled in his ability to cover the technical aspects of a product while explaining it in a way that the average Joe can still understand what all the mumbo-jumbo means! If you're new to the audiophile world, Zach is your go-to-guy!

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