Our smartphones are made up out of a lot of different components. When we cover them in reviews and news, we tend to focus on things like display quality, processor speed, cameras, etc. Those are all very important, but one feature that tends to often go unmentioned is Bluetooth.
When you think about just how regularly we use Bluetooth, that's kind of silly. We rely on the wireless standard for listening to music on Bluetooth headphones, playing games with controllers, using a mouse and keyboard for productivity work, and so much more.
The core idea of Bluetooth has remained the same since the introduction of version 1.0 back in 1999, and right now, we're going to take a look back at all of Bluetooth's many iterations, starting with the first one and going up to the 5.1 standard that was released in 2019, to understand where it started and how we got to where we are today.
Bluetooth 1.0 — 1.2
After the Bluetooth Special Interest Group (also known as SIG) was formed in 1998, the Bluetooth 1.0 specification was released a year later in 1999.
The first phone to use Bluetooth was the Ericsson T36, which was unveiled in 2000. However, it wasn't actually available for purchase until 2001 when Ericsson released the revised T39 mobile phone. The Ericsson T39 used Bluetooth 1.0b, which was a mild successor to Bluetooth 1.0a.
Compared to the Bluetooth we know today, Bluetooth 1.0b was very slow and unreliable. It had a maximum data transfer speed of 732.2kbs and could only stay connected to devices within a range of 33 feet. It can be easy to complain about Bluetooth being a pain to use today, but back then, the experience was substantially worse.
Also, with such slow data transfer speeds, Bluetooth wasn't really designed for listening to music the way it is now. Instead, its main purpose was for wireless Bluetooth headsets for making/receiving phone calls.
In February 2001, Bluetooth 1.1 hit the market. It set out to fix a lot of the usability complaints with Bluetooth 1.0, and while it still had the same max data transfer speed, it introduced support for up to seven simultaneous connections and made it possible to have Bluetooth connections on non-encrypted channels — one of the biggest drawbacks to Bluetooth 1.0.
Fast forward a couple more years, and Bluetooth 1.2 was ready to shine in November 2003. It was the first Bluetooth update that increased the data transfer speed, kicking things up to 1Mbs.
Bluetooth 1.2 also benefited from making devices faster and easier to discover, was backward compatible with Bluetooth 1.1, and introduced something called "Adaptive Frequency Hopping" that made Bluetooth more resistant to interference from radio frequencies.
Another big win for Bluetooth 1.2 was its use of Extended Synchronous Connections. The main purpose of this was to improve the quality of phone calls over Bluetooth, with it giving users an option to increase latency in favor of better data transfer for high-quality audio.
Bluetooth 2.0 and 2.1
Bluetooth 2.0 was the first main number update for Bluetooth, and it was well-deserving of the big name change.
This is when EDR — Enhanced Data Rate — came to Bluetooth, enabling data transfer speeds that were three times as fast. EDR boasted a bit rate of 3/Mbs, but in real-world use, Bluetooth 2.0 was only capable of 2.1/Mbs. Even so, it was a huge step forward for the standard.
Along with better wireless performance, thanks to the increased speed, Bluetooth 2.0 and its use of EDR also allowed for better battery life on devices that used it compared to Bluetooth 1.2. In 2005, former Executive Director of the Bluetooth SIG, Mike Foley, noted that a wireless headset with Bluetooth 1.2 may only last 90 minutes on a charge, whereas one with Bluetooth 2.0 could be used for over four hours on a single charge.
Bluetooth 2.1 was a modest follow-up to 2.0, and it was unveiled by the SIG in July 2007.
The main draw to Bluetooth 2.1 was that it offered a simpler pairing process between devices, utilizing its "secure simple pairing" system. Similarly, Bluetooth 2.1 introduced the option to pair devices using NFC (the same technology used by Google Pay and Apple Pay for contactless payments).
There was nearly a two-year gap between Bluetooth 2.1 and 3.0, with the latter being adopted by the SIG in April 2009. Where EDR was the main draw to the 2.0 and 2.1 days, Bluetooth 3.0's claim to fame was its HS — high-speed channel.
In theory, Bluetooth 3.0 could achieve data transfer speeds up to a whopping 24/Mbs. However, those speeds didn't happen solely over Bluetooth. Instead, Bluetooth 3.0 established a link connection to the 802.11 protocol (AKA, Wi-Fi).
With such vastly-improved speeds, Bluetooth was finally ready to go beyond audio transfers. Now, it was fast enough to stream video wirelessly between devices.
This is one of the biggest speed bumps Bluetooth has ever seen, and it was also the last iteration of the wireless standard before we were introduced to the world of Bluetooth Low Energy.
Bluetooth 4.0 — 4.2
That brings us nicely to June 2010. This is when the SIG formally adopted Bluetooth 4.0, and in October 2011, the iPhone 4S debuted as the first phone to use the new wireless protocol.
With Bluetooth 4.0, the big focus here was on its new Bluetooth Low Energy technology — also referred to as BLE. BLE was designed to offer more efficient connections to smaller wireless devices — often seen in fitness trackers and other smart wearables that don't require a lot of power.
When BLE was first introduced, there was a waiting period for consumers to see its full usefulness as we waited for devices to adopt the standard. Today, however, it's become an expected feature in any gadget that can benefit from it.
Bluetooth 4.0 retained the same 24/Mbs speed when used with non-BLE devices, along with adding 128-bit encryption for enhanced security.
The introduction of Bluetooth Low Energy was great — the ease of connections to Bluetooth beacons not so much.
Bluetooth 4.0 also brought a change that wasn't so great -- the ability for a one-way connection to a Bluetooth beacon. Besides beneficial uses like in-home patient health monitoring or indoor navigation, beacons can be used for location tracking and advertising purposes without user consent. Both Apple and Google took advantage of one-way Bluetooth beacons and offer solutions that are cheap and easy to deploy for businesses that want or need the technology.
December 2013 saw Bluetooth 4.1 rear its head for the first time, and despite the .x update, 4.1 brought quite a few welcome goodies to the wireless world. With Bluetooth 4.1, we saw the wireless connection play nicer with 4G radio signals and device-makers get the option to create their own timeout routines for devices (resulting in better overall power management).
The last big change for 4.1 was that it allowed Bluetooth devices to perform as both a hub and point at the same time — meaning smartwatches and fitness trackers could more seamlessly communicate information to smartphones and vice versa.
Rounding out the Bluetooth 4 era, we have Bluetooth 4.2. Bluetooth 4.2 entered the world in December 2014, and it marked a big shift for the standard in regards to its role in the Internet of Things (IoT).
Bluetooth 4.2 featured the Low Energy Secure Connection, among other standards, allowing for improved speed and privacy with all sorts of connected devices. The big draw, however, was Bluetooth 4.2's adoption of IP connectivity.
Another perk to Bluetooth 4.2 was its increased privacy, specifically the fact that Bluetooth 4.2 devices couldn't be tracked unless a user specifically gave permission.
Bluetooth 5.0 and 5.1
Bluetooth 5.0 was both a technical and branding update for the Bluetooth standard when it was officially rolled out in July 2016. On the technical side of things, we saw an increase in maximum range up to 800 feet, along with significantly faster max data transfer speeds up to 50/Mbs. Similarly, Bluetooth 5.0 added the ability to transmit audio between two devices at once — allowing for simultaneous audio playback on two headphones at once, sending audio to multiple speakers in a home, etc.
The SIG also focused on more IoT upgrades for Bluetooth 5.0, with this version adding support for even better low-energy usage and options for connections that use more bandwidth or need to reach longer ranges.
As for the branding change, Bluetooth 5.0 isn't actually referred to as Bluetooth 5.0. Instead, the SIG simply calls it "Bluetooth 5." The idea here was to make Bluetooth versions easier to understand and not as complicated as they've been in the past.
Bluetooth 5's new naming scheme aims to make it easier to understand the wireless protocol.
Phones with Bluetooth 5 / 5.0 started coming out in 2017, so chances are, the handset you're reading this article on is equipped with it.
With all of that said, there is also a Bluetooth 5.1 that we should talk about. It's the latest version of Bluetooth, and it was unveiled in January 2019.
Connection speed and reliability both saw improvements with 5.1, along with the ability for Bluetooth to determine the exact location of a device by analyzing the direction of connected products.
Something else that was introduced in Bluetooth 5.1 is the ability for Bluetooth devices to broadcast that they're available for pairing/connecting. The SIG calls this "Randomized Advertising Channel Indexing", and it makes it much easier to see what Bluetooth devices around you can actually be connected to — something that could potentially be quite helpful if you're in an environment that's crowded with other people's devices (such as a coffee shop or airport).
And with that said, that concludes our little history lesson.
It can be easy to complain about how bad Bluetooth is, but compared to where we started, the current implementation is light years ahead of what was offered with Bluetooth 1.0.
The wireless protocol is constantly changing and evolving, and as the years go on, it'll continue to do just that.
What lies ahead for Bluetooth 6 remains unclear, but when the SIG decides to announce what's new with the next generation of wireless connectivity, we'll be sure to let you know.