In today’s world, using Bluetooth headphones to listen to music or wearing Bluetooth wristbands while running is nothing new. However, you might be surprised to learn that someone has researched Bluetooth tampons, aiming to solve the embarrassing problem of “leakage” during menstruation.
丨Image Source: trackmyflow.com
A company called my.FLow has designed a tampon with an extra long string that connects to a Bluetooth module worn on the waist. With this tampon, you can check your “flow” anytime on your phone.
丨Image Source: trackmyflow.com
While you may not use a Bluetooth tampon right away, this product still makes one realize that Bluetooth technology has permeated our lives to such an extent.
In 2018, 100% of smartphones, tablets, and laptops produced were equipped with Bluetooth, and around 800 million Bluetooth audio devices, such as speakers and headphones, were manufactured that year. (Data Source: ABI Research)
丨Image Source: fossbytes.com
Everyone is using Bluetooth, yet we know almost nothing about it. So, what exactly is Bluetooth?
The story of Bluetooth dates back over 20 years.
In 1996, Nokia was the undisputed leader in the communications industry. They believed that short-range wireless communication technology had great potential and began research.
At the same time, companies like Intel and Ericsson were also researching this technology, each with their own projects and standards. However, everyone knew that having a single global standard was more reliable than multiple competing standards, so these companies formed a Special Interest Group (SIG) to develop a common standard for short-range wireless communication technology.
Although these communication giants formed a group, they couldn’t agree on a name for their creation. Each company proposed various names for the technology, and ultimately, the name “PAN” (Personal Area Network) proposed by IBM won the vote.
But why is it called Bluetooth instead of PAN?
When they tried to register the name “PAN,” they found that there were already thousands of products with that name, much like naming a child “Wang Wei” in our country.
However, since the technology was about to be launched and they didn’t have time to prepare another name, they remembered “Bluetooth,” which was an internal nickname they had been using. Thus, the quirky and playful name “Bluetooth” was born.
Fortunately, the backup name “Bluetooth” came through at a critical moment; otherwise, this technology might have been named “Flirt,” which means “to flirt.” This proposal was inspired by a Western saying, “Getting close, but not touching,” which actually aligns well with how Bluetooth works.
However, if we were to say, “Let’s flirt with Bluetooth,” it would certainly be a bit embarrassing…
The name “Bluetooth” was suggested by Jim Kardach, an engineer from Intel within the Bluetooth Special Interest Group.
丨Image Source: newsroom.intel.com
Once, he and Sven Mattisson from Ericsson were at a bar discussing history, and Sven mentioned a book called “The Long Ships,” which tells the story of King Harald of Denmark uniting the territories and religious disputes, bringing Denmark and Norway together into the Scandinavian Peninsula. When he got home, he coincidentally saw this King Harald in another book about Vikings, and he suddenly got inspired—
Unifying different countries and beliefs is quite similar to their goal of unifying the Bluetooth standard! Thus, he proposed the name “Bluetooth,” derived from King Harald’s name.
丨Image Source: newsroom.intel.com
The classic Bluetooth logo is formed by combining the initials H (ᚼ) and B (ᛒ) of this king’s name. ᚼ and ᛒ are runes used in medieval Scandinavia, and this extinct script has been preserved in this fascinating way.
丨Image Source: newsroom.intel.com
By the way, this king was called “Bluetooth” because he had a blue tooth…
No matter which brand of Bluetooth speaker/headphones/fitness band you buy, they can always connect to your phone or computer. Bluetooth devices seem to have a tacit understanding; as long as they are turned on and close enough, they can pair successfully, which is much easier than two people pairing up. Why is that?
Because all Bluetooth devices operate on the same frequency band.
Over time, as they work together, the chances of finding a compatible partner increase significantly.
丨Image Source: 新浪微博@冯绍峰
Now, back to this frequency band. Bluetooth operates in the ISM band (Industrial Scientific Medical Band). The ISM band is reserved worldwide for industrial, scientific, and medical use. Using the ISM band does not require a special license, so there are no costs associated with “licensing.”
Just like a toll-free road that gets congested, the ISM band is also crowded with various devices. Your Bluetooth, home Wi-Fi, microwave, cordless phone, and car door opener all use this ISM band, leading to a very crowded and noisy “road.”
Therefore, to avoid interference from other devices, Bluetooth employs a technique called Frequency-Hopping Spread Spectrum (FHSS). Bluetooth specifically operates in the frequency range from 2401MHz to 2479MHz, with each “channel” occupying 1MHz, totaling 79 channels. Bluetooth signals randomly hop between these 79 channels, quickly switching to the next channel when encountering interference.
You can imagine it like changing channels on your TV; when you see a fuzzy channel, you quickly switch to a clearer one, which is the same concept…
Of course, Bluetooth “changes channels” much faster than you do, at a rate of 1600 times per second. If you were to change channels at your speed, your Bluetooth headphones would probably disconnect a thousand times while listening to a song.
How do two devices with Bluetooth modules successfully connect?
Actually, whether you are using your phone’s Bluetooth to unlock a shared bike or typing these words on a Bluetooth keyboard, there is a master-slave relationship between the two Bluetooth devices.
Bluetooth modules are designed based on a master-slave architecture, meaning that Bluetooth technology stipulates that during communication between any two Bluetooth modules, one must act as the “master” and the other as the “slave” for the connection to be established. (The analogy is a bit strange…)
The “slave” device enters broadcast mode, sending out signals, and only the “master” can initiate the search and pairing process.
The pairing process is essentially a scheduled “date” where the master and slave synchronize their hopping frequencies.
Sorry, I posted the wrong image; it should be this one:
Once the two devices synchronize their hopping, they successfully connect and can exchange data.
Don’t underestimate your phone; its Bluetooth module can sometimes be an S and sometimes an M—of course, I mean it can be a “slave” or a “master”; the master-slave relationship between two Bluetooth devices can switch based on communication needs.
Now, do you understand Bluetooth?
References:
Bluetooth.com
CSDN.net
trackmyflow.com
Tech History: How Bluetooth got its name, Jim Kardach, EETimes, 2008
Why Is Bluetooth Called “Bluetooth”? How Did It Get Its Name And Logo? Adarsh Verma, FOSSBYTES, 2017
Discussion Topic
Recommend your favorite Bluetooth devices!
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Editor = Ms. Leng Suan Ling
Cover Image Source = boredpanda
GIF Source = GIPHY
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