To stay connected with people and devices, we have adopted various technologies that allow us to become increasingly connected. One of the most commonly used innovations is Bluetooth – a wireless connectivity standard that uses radio signals to connect and communicate with devices. The technology connects computers and electronics, like our phones to other phones, wireless headphones, cars, keyboards, and other wireless technologies. From transferring files from your digital camera to your printer to synchronizing data between your fitness tracker and smartphone, Bluetooth connectivity has become a part of everyday life.
What is Bluetooth Technology?
Bluetooth technology is a form of short-range wireless communications that is used to transfer data between different electronic devices. Bluetooth is named after Harald Bluetooth Gormsson, a 10th-century Viking king who ruled Denmark and Norway between 958 and 985.
Bluetooth removes the need for cables, cords, and adapters, allowing us to send and receive data between bluetooth-enabled devices, synchronize information from a smartphone to a desktop PC, use a wireless mouse, and use a Bluetooth handsfree headset with a game console – all using the same core system. Bluetooth allows a device like a smartphone or tablet to communicate with up to five devices at a time. Incidentally, with the new version of the Bluetooth standard, you can stream audio to two different devices at the same time.
Bluetooth costs less to implement and uses less power than Wi-Fi. Also, the lower power makes it much less likely to cause or suffer from interference with other wireless devices in the same radio band (2.4GHz). However, the transmission speeds and range are lower than Wi-Fi local area networks that you may have in your home. For example, Bluetooth 3.0 + HS (high-speed Bluetooth technology) devices deliver up to 24 Mbps of data. That means it is slower than Wireless-A or Wireless-G standards, but faster than the 802.11b Wi-Fi standard. Over time, Bluetooth technology has evolved, and the speed at which it can transmit data has continued to increase.
How Does It Create a Connection?
With Bluetooth, small-area networking is taken to the next level. Wireless technologies like Bluetooth keep transmission power very low to save battery power and remove the need for user intervention. It’s a network standard that operates at two levels:
- Bluetooth provides agreement at the protocol level (products have to agree on how many bits will be sent at a time, when they are sent, and how the devices that communicate can be sure that the message sent is the same as the message received);
- Bluetooth provides agreement at the physical level and is a radio-frequency standard.
Devices on a Bluetooth network communicate via low-power radio waves on a frequency of 2.45 GHz. That frequency band has been set aside by international agreement for the use of ISM (Industrial, Scientific, and Medical) devices.
Unlike IR (infrared) connections, which can only be one-on-one, Bluetooth can handle communicating with multiple devices (up to five) simultaneously in the same 10-meter (32-foot) radius. One might think that all those devices might interfere with one another, but that is unlikely because the technology uses spread-spectrum frequency hopping. This is a technique that makes it rare for more than one device to transmit data on the same frequency and at the same time. Thanks to the technique, one device will use up to 79 randomly chosen frequencies that change or hop from one to another regularly.
When connecting wireless devices via Bluetooth, Bluetooth transmitters change frequencies 1,600 times per second, which means that multiple devices make full use of the radio spectrum. It is unlikely that two transmitters will be on the same frequency at the same time because every transmitter uses this spread-spectrum transmission technique automatically. The technique minimizes the risk that baby monitors or portable phones will disrupt Bluetooth devices because any interference on a specific frequency will last just a fraction of a second.
What is a Piconet?
Piconet is a personal area network (PAN) that Bluetooth systems create. It may fill a room or encompass a distance no larger than the distance between the Bluetooth headphones on your head and the smartphone in your pocket. When a piconet is created, members randomly switch or hop frequencies in unison so they can stay connected with one another while avoiding other piconets that are operating in the same room. The piconet can contain 2 – 8 Bluetooth member devices, typically with a single master device and up to 7 slaves.
The master device in the network governs the communication link and traffic between itself and other slave devices that are associated with it. Slave devices synchronize their receive/transmit timing with that of the master’s, and the master device governs their transmissions. A slave can begin its transmissions in a time slot explicitly reserved for use by a slave device, or in a time slot immediately following the time slot in which it was addressed by the master device.
For example, your mobile phone may be the master audio device, while all the other devices in your piconet will be slaves. Connected devices could include your GPS receiver, headset, car stereo, MP3 player, and others.
Versions of Bluetooth Technology
Let’s take a look at all the different versions of Bluetooth technology and their specifications.
- Bluetooth v1.0 to v1.08: mandatory Bluetooth hardware device and address
- Bluetooth v1.1: IEEE standard 802.15.1-2002
- Bluetooth v1.2: faster connections
- Bluetooth v2.0+EDR: enhanced data rate
- Bluetooth v2.1: secure simple pairing
- Bluetooth v3.0: high-speed data transfer
- Bluetooth v4.0: low-energy consumption
- Bluetooth v5.0: Internet of Things (IoT) focus
All the improvements made to Bluetooth were to Bluetooth Low Energy specifications which were initially introduced in version 4.0. With Bluetooth 5.0 devices, the data transfer speed can be up to 2 Mbps (double the speed that v4.2 supports) and devices can communicate and send files over distances greater than 240 meters (800 feet), which is four times the short distances allowed by v4.2.
Today, you can get devices that support Bluetooth v5.0, such as Samsung Galaxy 8, iPhone 8 and 8 Plus, and iPhone X. However, you will also need Bluetooth 5.0 peripherals to be able to reap the benefits of increased speed. Bluetooth technology is backward compatible, meaning that your older Bluetooth devices and Bluetooth 5.0 devices will work together.
Bluetooth v5.1 was introduced in January 2019, while v5.2 was available around January 2020.
Types of Bluetooth Technology
The Bluetooth protocol connects to devices and executes specific functions based on “Class of Device” or CoD. Bluetooth connects to a device, determines its Class, and then loads a specific profile relevant to that Class. There are many profiles (approximately 36) and some examples include the Advanced Audio Distribution Profile (A2DP), Human Interface Device (HID), Hands-Free Profile (HFP), and Headset Profile (HSP).
Bluetooth-enabled devices typically fall into the following broad categories:
- Bluetooth GPS device
- Bluetooth headset
- In-car Bluetooth headset
- Stereo headset
- Bluetooth-enabled webcam
- Bluetooth-equipped printer
- Bluetooth keyboard and wireless mouse
Bluetooth GPS device
A Bluetooth GPS device is an improvement to traditional GPS because destinations and directions can be communicated through voice commands. You can state the address to the GPS system, and the GPS can provide directions on the screen and via voice.
A Bluetooth headset is a type of Bluetooth audio device typically used in combination with smartphones or other computers and electronics since users can receive or make calls without using hands or wires.
In vehicles, audio systems can be connected via Bluetooth. You can make or receive calls with the help of the car Bluetooth speaker system by wirelessly connecting your mobile phone.
Stereo headsets work just like a traditional headset, just without any wires. It is a wireless headset connected to a music player, allowing you to hear the music from the audio device source (typically a smartphone) via wireless Bluetooth communication.
Bluetooth webcams can be connected to a PC wirelessly, and wireless capabilities add mobility to the device (unlike traditional webcams which must remain near the computer).
These can print documents from any Bluetooth device. Devices that can be connected via Bluetooth to a printer would include a laptop, smartphone, PDA, and a digital camera. These devices are synchronized with the printer and need to be in range to connect to it.
A Bluetooth keyboard also works without the help of the cords or wires connected to a laptop or computer. It also works for smartphone devices or mobile phones.
Bluetooth and the Internet of Things (IoT)
In the Industrial Internet of Things (IIoT), machines often need to receive or send short bursts of data in extremely noisy environments. There may be hundreds of devices and sensors sending the data, so setting up a Wi-Fi connection can be a huge hassle. Bluetooth has a lower bandwidth, which is usually deemed as a drawback, but in industrial applications, higher bandwidth is not needed. Furthermore, Bluetooth technology is useful in a smart home setting because home devices can also communicate on lower bandwidth. Bluetooth is much easier to set up.
Newer versions of Bluetooth allow for individual devices to communicate even if one device is disconnected or runs out of power. For example, if your door locks, lights, refrigerator, washer, and HVAC system are all connected, you wouldn’t want them all to disconnect just because one device went down. Low range is still a major drawback of Bluetooth connectivity, which could be problematic if your residence is large.