How Bluetooth Works

Hey, let me paint a picture for you: I was 16, just got my first car, and, man, was I excited to see that it had a 5-disk CD player!

“Now I don’t have to listen to the radio while I’m driving – I can choose what songs to listen to!”

Fast-forward “a few” years later, and I’m using Bluetooth to play music from my phone through my car speakers.

My, how the times have changed.

So, how does it all work?

My wireless speakers, earphones, hands-free calling – what’s the magic behind Bluetooth tech?

Before I get into that, let’s take another trip down memory lane, only, this time, we’re going a little further back!

The idea of what we call “Bluetooth” today was first introduced back in 1989.

Dr. Nils Rydbeck, who was the chief technology officer at Ericsson Mobile, and inventor Dr. Johan Ullman had this revolutionary idea to develop a pair of wireless headsets.

Because, well, let’s be honest, cords and wires are annoying!

It was a major undertaking, so they brought Dr. Jaap Haartsen on to the project.

A mere 5 years later, he’d be the engineer who made the breakthrough and came out with the first protocol.

It took a few more years to perfect the technology.

But finally in 1999, they presented their first hands-free headset to the world at the Comdex computer exposition and trade show in Las Vegas.

It even won the Best of Show Award!

And it was dubbed “Bluetooth,” which then begs the question, “Where does the strange name come from?”

Well, at the time, three companies were working separately to create short-range radio technologies that would connect computers and different devices using short-wave frequencies.

But since the invention was in its early stages, Intel, Ericsson, and Nokia decided that the best way to proceed was to create a single wireless standard.

Jim Kardach, who was working for Intel, happened to be reading a historical book about how the Viking King Harald “Bluetooth” Gormsson united Denmark and Norway.

That story inspired Kardach to propose his idea of calling this single short-link device that would unite communications “Bluetooth.” So, that was it!

They also paid tribute to the great Viking king when they came up with the logo.

Hmm, just looks like a B to me.

But if you examine it a little closer (and you happen to know the Nordic alphabet), then you’ll see that the logo is formed from two different symbols.

They represent the initials of the king: H and B for Harald Bluetooth.

Ok, sorry to geek out there on the history.

Let’s get into the meat and potatoes of this mysterious Bluetooth technology.

Bluetooth works a lot like Wi-Fi.

It uses radio waves to send data between devices at short distances.

Now, whereas Wi-Fi uses radio waves to transmit data between your router (where your Wi-Fi comes from) and your device, Bluetooth does it between devices.

So, basically, if two things have a Bluetooth option, then they can transmit data between each other.

This “communication” of sorts is measured in Gigahertz.

For both Bluetooth and Wi-Fi, it’s usually at the 2.4 Gigahertz frequency.

That means those radio waves (imagine them just as they are, waves!) are moving in hoards and really fast.

That is, 2.4 billion waves per second!

That’s why when you, say, turn your Bluetooth mouse on, the cursor starts whipping around your computer screen in an instant!

Now, even though Bluetooth still works at the 2.4 Gigahertz frequency just like Wi-Fi, it mostly works at shorter distances and uses muuuch weaker signals – just 1 milliwatt of power.

You know those little laser pointers your cat loves so much?

They put out 5 milliwatts of power, so that goes to show you how weak just 1 is.

Bluetooth doesn’t need as much power as Wi-Fi does because it’s not really doing as much work.

But the cool thing is that Bluetooth can connect to 8 devices at the same time without any interference from other wireless items like garage doors or baby monitors.

(Wi-Fi can have issues with that.) So, here’s a real-life example: let’s say you’re listening to music from your laptop using your wireless headphones and you’re also typing on your computer with your wireless keyboard.

The Bluetooth transmitters in both your computer and your devices use 79 different frequencies in that range.

To prevent your music from getting in the way of your keyboard, it changes frequencies 1,600 times every second!

When you try to connect a Bluetooth device with your phone, then a sort of conversation takes place between the two of them.

They present their data and decide on whether they need to exchange information or if one of them needs to control the other.

After this short digital dialogue ends and the two devices agree on their roles, they connect together to form a network.

That Bluetooth network of connected devices is called a “piconet”.

Once their connection is established, they begin their frequency hopping in order to continually stay connected and avoid interference.

You can even take a device with you to another room, and it’ll keep working.

As long as you don’t go too far, that is!

Bluetooth is such a huge part of our everyday lives, yet most of the time it goes unnoticed.

So if you’re wondering what devices use Bluetooth nowadays, the answer is almost all of them.

Phones, headphones, earbuds, speakers, stereos, TVs, cameras, cars, tablets, game consoles, you name it!

And if you were to watch them all at work, it’d be quite the spectacle.

Imagine if you could see that “piconet” of radio frequencies swirling from all these Bluetooth devices in your home.

You’ve got your wireless mouse and computer “chatting” with each other, your Bluetooth speaker has its own conversation going on with your phone.

And the best part is that none of them so rudely intervene in the others’ conversations!

That’s not only thanks to frequency-hopping.

It’s also because each device has its own “address” programmed by the manufacturer.

So even if your wireless mouse gets a message from your TV, it’ll just automatically ignore it because they have different addresses.

But the way Bluetooth works raises a few security questions as well.

Just like all wireless networking setups, there’s always the legitimate concern of sending personal data using radio waves and that data falling into the wrong hands.

When Bluetooth first came out, it was really easy for someone to access your data without your permission.

But over time this technology has become more secure.

Bluetooth manufacturers are aware of the risks, so they’ve already done a lot to make devices more protected against security threats.

You see, in almost all of our personal gadgets, there’s the “trusted devices” option that enables you to share data without permission while others need permission to access your device.

But let’s not forget about spam.

There’s this trend called bluejacking where a person or company can send you their electronic business card or an ad as a text message using Bluetooth.

Of course, when you see that, you either ignore it or panic!

But this is something that mostly happens in public places where everyone is using their phones.

You can prevent it from happening to you by making your Bluetooth device non-discoverable when you’re out and about.

And if it does happen to you, don’t worry.

Just turn your Bluetooth off and remove the attacker’s device from your trusted ones.

Now with those bluejackers busted, let’s talk about the health concerns.

Unfortunately, there’s not enough evidence and research done on Bluetooth to determine if it’s harmful for people or not.

And it’s also quite tricky because Bluetooth waves are just one part of the wireless smog that surrounds us every single day.

But perhaps this will be comforting to know: the amount of non-ionizing radiation present in Bluetooth headphones is a lot less than what’s in a typical cellphone.

So if you’re worried about Bluetooth affecting your health, you should probably give up your phone first.

And, still, your phone isn’t a cause for alarm either.

There are regulatory organizations put in place to keep the public safe from being exposed to too many radio frequencies from our devices.

For example, The Federal Communication Commission checks that cellphone manufacturers don’t sell devices that go over what scientists say is the limit of how many radio frequencies the human body can absorb from one gadget.

That number is called the Specific Absorption Rate (SAR), and you can always check which models have the lowest if you’re in the market for a phone.

So don’t worry too much about it.

The health aspect is always under check and is constantly being studied.

All in all, I still say Bluetooth is a lot better than getting tangled up in cords and having to change CDs in your car!

So, do you use Bluetooth in your everyday life and what for?

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