Bluetooth: History and Uses

 

   It is very easy to not realize that we are using certain technologies in daily life. We take a lot of things for granted now, like WiFi, cameras, and everything else that a mobile phone has. However, there is another, less-talked-about capability that makes the phone seem more magical. Bluetooth abilities are quite powerful, and function without any WiFi. It connects devices within a ten meter radius and can simultaneously send audio and microphone data between devices.

    Invented in 1994, Bluetooth aimed to add connectivity to computer peripherals. These would be headphones, keyboards, or mice that connect to a computer. The inventor company, L. M. Ericsson, had a team developing the technology, led by Jaap Haartsen, a Dutch electrical engineer. The name is unusual in that it is named after a quite unrelated person: Harald Gormsson of Denmark. He ruled over Denmark, uniting the area under a singular ruler. When the team was coming up with a codename, they named it after King Harald, who united Denmark in a similar way that Bluetooth intended to unite computer peripherals. Harald was called “Bluetooth” due to a prominent rotting blue tooth.
    

At the time, the other competition was HomeRF and the IrDA system. They are all pretty similar, but Bluetooth was the one that really caught on. HomeRF, similar to Bluetooth, uses a 2.5 gigahertz radio frequency to transmit information, while IrDA utilizes infrared light beams. This means that IrDA only functions by a line of eye contact, and will not send information through walls. IrDA and HomeRF also send more information between devices, but that requires a larger amount of power that makes these inventions closer to WiFi. IrDA is also limited to only two devices in a network, and has a range of only one meter.


    The goal of the product was to eliminate cables in general life. That is why the range of Bluetooth is not very far, but it is utilized a lot. Things like Airpods, headphones, mice, and keyboards often come today with Bluetooth capabilities. When a device is in range, it will automatically pair if it has been set up before, and it will disconnect when out of range.

    But how does it work? The Internet of Things (IoT) often works with seemingly-magical technology that connects us to devices and devices to each other. In a Bluetooth network, each device that is connected is called a “piconet”. These piconets function by sending data from a “master” to a “slave”. The “master”, often a device like a phone, will send data to the other devices in the piconet and direct them on what to do with the data. The roles may switch during use of the devices. A collection of two to eight piconets, or a scatternet, can have multiple “masters” at any one time. We see this functioning with my Bluetooth headphones that can connect to both my computer and my cell phone at the same time. All piconets in a scatternet operate on the “master”’s clock, so everything is locally set.

    Other competitors had similar features, but Bluetooth eventually won the long game. It is extremely cheap, and its slow transmission speeds mean that it requires little power. It can also handle several simultaneous streams of data, as well as connect through walls and nonmetal objects. It also uses Industrial, Scientific, and Medical (ISM) bands in order to transmit the information, which are globally available bands that are set aside for radio usage. This means that Bluetooth can be used all around the world. It is also extremely efficient, jumping between 79 different radio frequencies all close to 2.4 gigahertz. Bluetooth is so low-power that it rarely interferes with the WiFi signals that pass through this band.
    

    In general, Bluetooth accomplished exactly what it set out to do, and even more. Computer peripherals are utilized with Bluetooth, but so are new applications like biometric data sensors, indoor positioning technology, home lighting, smart appliances, and other smart technologies. Many of these new smart applications of Bluetooth use the new version, Bluetooth Low Energy (BLE). Bluetooth Classic (which is what I have been describing so far), uses a low amount of energy in the first place, but BLE uses even less. It stays dormant for hours at a time and then will send a small amount of data as necessary before becoming dormant again. This is helpful when we need data collected every once in a while, but not constantly. The health applications of BLE are especially exciting, so patients can decrease the amount of cables they are hooked up to.

        One unintended drawback of Bluetooth is the lack of security. There is often no encryption necessary to connect devices together, which exposes the connection to hackers at some points. When pairing a device initially, Bluetooth devices require initial configuration information like device IDs and security keys, but authentication is not mandatory. Hackers can implant incorrect information or pretend to be a receiver during this part of the process. However, that does not happen often, and encryption can be turned on while pairing.

    Bluetooth is extremely useful in everyday life when we don’t want a mass of wires following us around. It is unobtrusive, inexpensive, and costs very little energy. The new BLE and Bluetooth 5.0 versions are especially exciting, expanding what the inventors thought Bluetooth could possibly accomplish.