The chances are that you’ve heard about Bluetooth numerous times before. But perhaps you are wondering what is behind this buzzword? What is Bluetooth? How does Bluetooth work? Great, we are set to give you some answers.

Bluetooth is a wireless communication technology that works at short ranges.  It allows devices, such as smartphones, laptops and other peripherals to communicate and share data wirelessly.  It has started as a technology for a particular niche but now is widely available on almost all type of devices.

We use Bluetooth on a daily basis, without you perhaps even noticing it. The technology connects our phones to our headphones, laptop, and even car entertainment systems. Its primary purpose is to replace cables used to connect devices, yet maintain a secure communication between devices.

A bit of Bluetooth history

Bluetooth was originally developed in 1994. Its name comes from Harald Bluetooth, a 10th century Danish King who used to unite warring regional factions. Accordingly, Bluetooth also brings together devices across various industries by making use of a unifying communication standard.  Initially, its goal was to replace the RS-232 cables that were used for transmitting data.  It took four more years before Bluetooth had formalized specifications and released to the world.

How does Bluetooth work?

Just like other wireless technologies for home and office use (wireless routers and cordless phones, for example), it also uses the 2.4GHz frequency, or more specifically, 79 different channels centered on it.  It creates a wireless network with a radius of 33 feet, known as a personal area network (PAN), or piconet.

You can have two to eight devices on PAN network without worrying about devices interfering with each other. Devices randomly choose one of the 79 available channels and attempt to connect. If the channel is taken, they randomly switch to another channel until they find one that is free. This technology is known as spread-spectrum frequency hopping.

Bluetooth versions explained

Bluetooth V1.0

It is no secret that the first versions of Bluetooth, V1.0, and V1.0B had a lot of problems.  There were compatibility issues, and the maximum data transfer rate was 1 Mbps, which is extremely slow by today’s standards. Fortunately, almost all devices that used the initial versions of Bluetooth are now retired.

Bluetooth V1.1 fixed many issues of V1.0B and introduced the Received Signal Strength Indicator (RSSI).

Later in 2001 the updated V1.2 was released featuring some significant enhancements.  It allowed for faster discovery and connection, as well as an adaptive frequency-hopping spread spectrum, that avoided crowded frequencies in the hopping sequence.  In practice, it also had a higher transmission speed of up to 721kbit/s.  There were also the Extended Synchronous Connections, to improve audio links’ voice quality by allowing for corrupted packets to be retransmitted.

Bluetooth V2.0

A few revisions later V2.0 was released in 2004.  With an Enhanced Data Rate (EDR), it allowed for maximal transfer speeds of up to 3 Mbit/s, becoming a common variant. However, the maximum rate, allowing for inter-packet time and acknowledgments, was 2.1 Mbit/s.  EDR also provided lower power consumption as well, by using a reduced duty cycle.  The specification was published as “Bluetooth v2.0 + EDR”, implying that EDR is an optional feature.

Bluetooth 2.1 + EDR was introduced on the 26th of July, 2007. The introduction of Secure Simple Pairing was a headline feature. It improved Bluetooth devices’ pairing experiences while increasing security at the same time. That’s where we saw EIR, or extended inquiry response, that allows for better filtering before connection by providing more information.

Bluetooth V3.0

Only two years later, in 2009, the major release V3.0 + HS came out. The HS abbreviation stands for High Speed and highlights significant changes in the data transfer rate. It pushed the maximum theoretical data transfer speeds to 24 Mbit/s, but they weren’t over the Bluetooth link itself.  That link was only used for negotiation and establishment, with the traffic going through the 802.11 protocol.  Other notable improvements were the inclusion of Enhanced Retransmission Mode (ERTM), as well as alternative MAC and PHYs for transferring large quantities of data.

Bluetooth V4.0

Bluetooth V4.0, also known as Bluetooth Smart, was introduced in June 2010 and is still the most popular version nowadays. It featured the Bluetooth Low Energy, which considerably lowers power consumption.  There was also the introduction of cost-reduced single-mode chips, which enable compact devices at the lowest possible cost. Later V4.1 was introduced as an incremental update that improved consumer usability, while the focus of V4.2 was the Internet of Things.

Bluetooth V5.0

The latest and the current version is Bluetooth is 5. It makes a further focus on the Internet of Things. We also got some phones that launched with Bluetooth 5, such as the Samsung Galaxy S8, which allowed for dual output via two Bluetooth devices simultaneously. The latest release allows either to double the speed (2 Mbit/s burst), at a shorter range, or increase the range four times, at a slower rate. Alternatively, you can push up to eight times the capacity with increased packet lengths.

Comparing Bluetooth to other wireless standards, Wi-Fi and ZigBee

Despite many peoples belief, Bluetooth is not the only wireless standard out there. Other alternatives, such as Wi-Fi and ZigBee are closely competing in many areas. The approach that each technology took is vastly different with the only thing being in common is the usage of 2.4GHz and now 5.0GHz frequency. With the rapid development of the smart home, we may be just at the start of the wireless war.

ZigBee is one of the most popular standards, especially with smart homes. Compared to Bluetooth, it requires a specialized device for control, often in the form of a smart hub.  Even though it uses very little power, ZigBee does allow for extended reach. It achieves it by using a mesh network configuration, where the individual smart devices create the network where they can relay signals to each other.

Wi-Fi works differently and requires a Wi-Fi router.  Each device is connected to that router, with the router having the connection to the internet. The setup allows you to control any device regardless of where you are as long as they are part of the same Wi-Fi network.

Because of the ubiquity of Wi-Fi, you’ll find that a lot of devices adhere to the standard. When compared to Bluetooth, Wi-Fi is power hungry and more expensive than both Bluetooth and ZigBee.

Bluetooth has a lower range than ZigBee, as it was originally designed for close distance communication. Compared to Wi-Fi, Bluetooth devices cannot be controlled remotely as they are not connected to the internet.

A notable advantage of Bluetooth is its mass adoption. Almost all portable devices support Bluetooth connectivity one way or another, and it doesn’t require any additional hubs or routers. It’s also relatively cheap to produce, making it the wireless standard of choice for many applications.

How secure is Bluetooth?

The common belief is that a wireless communication is always less secure than a wired one, which is true.  Since signals are basically going through the air, there is always a chance to have it intercepted. Bluetooth solves this problem by encrypting communication and adding a few more security features.

You can restrict your devices to only communicate with specific trusted devices, which is known as a device-level security.  Or, you could restrict what your gadgets can do with other devices, which is known as a service-level security.  In addition, Bluetooth device often shifts radio frequencies while paired, making it difficult for a signal to be intercepted.

At the same time, like with any other wireless technology, there are always some risks involved.  Things such as bluejacking (people sending messages to others’ devices), bluebugging (taking over your Bluetooth device without your knowledge) or bluesnarfing (downloading information from another person’s device without their knowledge) are always there. Bluetooth has addressed those concerns with respective security updates minimizing the chances of being hacked.

Keep in mind, however, to take reasonable precautions, such as changing the default pairing PINs and not connecting to random, unknown devices.  You might also want to switch off Bluetooth on your device when you’re in public, for an additional security.

What is Bluetooth tethering and Bluetooth share?

Bluetooth tethering and sharing are two of the most common uses for Bluetooth nowadays.  Bluetooth tethering allows you to share a mobile connection with another device that’s connected to yours.  Bluetooth sharing, on the other hand, allows you to wirelessly transfer files to another device. The data transfer rate, however, is limited by the version of Bluetooth being used.

Common Bluetooth limitations

Bluetooth is an amazing piece of technology, but like anything, it has its issues. Although the major concerns were addressed over time, there are still some minor gains to be had. For example, although Bluetooth Low Energy is a vast improvement, it can still drain battery power on mobile devices such as smartphones or smartwatches.  Newer versions have addressed this concern, but there is still some way to go. Additionally, the improvements in battery technology help a bit.

Another issue is the range. I did mention that the range tops out at around 30 feet, but you should also know that obstacles such as walls, ceilings, and floors can severely reduce the range.  Also, depending on the manufacturer and the device quality, you may still face pairing issues.

How do Bluetooth speakers and headphones work?

One of today’s most common uses for Bluetooth are speakers and headphones. Traditional models make use of cables, and those can often get in your way. Bluetooth lets you move around freely, without worrying that the cable might get caught on something.

With speakers, the widest Bluetooth acceptance is observed in outdoor portable speakers and shower speakers. If you are looking for Bluetooth shower speakers reviews or best portable Bluetooth speaker, please make sure to check our website for top picks. 

The only difference between traditional, wired speakers and Bluetooth speakers is that the audio signal gets transmitted via Bluetooth rather than physical wires.  That does, however, require that you pair your smartphone or computer with the speakers to establish a trust connection. Most of the time, it is a one-time affair, since the computer, and the speakers or headphones remember the devices they are paired to.  Next time you’ll need to switch on Bluetooth on both devices, and they should automatically pair.

One notable downside with Bluetooth speakers and headphones, when compared to traditional ones, is that they need to be charged. Since there are no cables, the electrical power to power drivers can only be generated from the battery. Depending on the device and the battery capacity being used, you may need to go through the charging process once in a while.  However, newer devices come with awe-inspiring battery life, such as the Sony 1000X M3, with 30-hour battery life, or the 20 hours of the BOSE QuietComfort 35 II.

Other common uses of Bluetooth 

Bluetooth is used for many different applications apart from tethering, sharing, and personal audio.  For example, both the Play Store for Android and the App Store for iOS have Bluetooth based games.  They require no internet connection, and you’ll need to be physically close to the other players, making the game very fun.

You could also connect other devices to your smartphone or computer via Bluetooth.  There is an abundance of good Bluetooth mice and keyboards on the market today removing the cables from your desk.  You could also connect a printer, and print from your mobile devices directly to the printer, as long as you are in the range. Alternatively, you can also connect a gamepad, such as Sony’s DualShock or Microsoft’s Xbox controller.

Bluetooth is also making its way into health care and personal care products such as shavers, toothbrushes, and flossing kits. If you are interested in best electric toothbrush consumer reports, feel free to check our latest review.

Lastly, many modern cars come equipped with Bluetooth. Driving and speaking with your phone in hands is dangerous, yet if you have your phone connected to the car’s audio system that channels sound through speakers, you can talk handsfree. You could also use the car speakers to play music or use the car’s navigation system to get live traffic updates via the cellular network.

Wrapping things up

Even though Bluetooth was initially made to solve one simple problem, it has evolved significantly to become a widely accepted standard. Phones, cars, speakers, smartwatches are only some examples of Bluetooth adoption, with many more coming. If you are like me and want to de-clutter the cables from your desk and living room, you might want to take a look at some of the top Bluetooth devices out there.