What is bluetooth communication

Bluetooth

Bluetooth is universal for short-range wireless voice and data communication. It is a Wireless Personal Area Network (WPAN) technology and is used for exchanging data over smaller distances. This technology was invented by Ericson in 1994. It operates in the unlicensed, industrial, scientific, and medical (ISM) band from 2.4 GHz to 2.485 GHz. Maximum devices that can be connected at the same time are 7. Bluetooth ranges up to 10 meters. It provides data rates up to 1 Mbps or 3 Mbps depending upon the version. The spreading technique that it uses is FHSS (Frequency-hopping spread spectrum). A Bluetooth network is called a piconet and a collection of interconnected piconets is called scatternet.

What is Bluetooth?

Bluetooth simply follows the principle of transmitting and receiving data using radio waves. It can be paired with the other device which has also Bluetooth but it should be within the estimated communication range to connect. When two devices start to share data, they form a network called piconet which can further accommodate more than five devices.

Points to remember for Bluetooth:

• Bluetooth Transmission capacity 720 kbps.
• Bluetooth is Wireless.
• Bluetooth is a Low-cost short-distance radio communications standard.
• Bluetooth is robust and flexible.
• Bluetooth is cable replacement technology that can be used to connect almost any device to any other device.
• The basic architecture unit of Bluetooth is a piconet.

Bluetooth Architecture:

The architecture of Bluetooth defines two types of networks:

Piconet:

Piconet is a type of Bluetooth network that contains one primary node called the master node and seven active secondary nodes called slave nodes. Thus, we can say that there is a total of 8 active nodes which are present at a distance of 10 meters. The communication between the primary and secondary nodes can be one-to-one or one-to-many. Possible communication is only between the master and slave; Slave-slave communication is not possible. It also has 255 parked nodes, these are secondary nodes and cannot take participation in communication unless it gets converted to the active state.

Scatternet:

It is formed by using various piconets. A slave that is present in one piconet can act as master or we can say primary in another piconet. This kind of node can receive a message from a master in one piconet and deliver the message to its slave in the other piconet where it is acting as a master. This type of node is referred to as a bridge node. A station cannot be mastered in two piconets.

Bluetooth protocol stack:

1. Radio (RF) layer: It specifies the details of the air interface, including frequency, the use of frequency hopping and transmit power. It performs modulation/demodulation of the data into RF signals. It defines the physical characteristics of Bluetooth transceivers. It defines two types of physical links: connection-less and connection-oriented.
2. Baseband Link layer: The baseband is the digital engine of a Bluetooth system and is equivalent to the MAC sublayer in LANs. It performs the connection establishment within a piconet, addressing, packet format, timing and power control.
3. Link Manager protocol layer: It performs the management of the already established links which includes authentication and encryption processes. It is responsible for creating the links, monitoring their health, and terminating them gracefully upon command or failure.
4. Logical Link Control and Adaption (L2CAP) Protocol layer: It is also known as the heart of the Bluetooth protocol stack. It allows the communication between upper and lower layers of the Bluetooth protocol stack. It packages the data packets received from upper layers into the form expected by lower layers. It also performs segmentation and multiplexing.
5. Service Discovery Protocol (SDP) layer: It is short for Service Discovery Protocol. It allows discovering the services available on another Bluetooth-enabled device.
6. RF comm layer: It is a cabal replacement protocol. It is short for Radio Frontend Component. It provides a serial interface with WAP and OBEX. It also provides emulation of serial ports over the logical link control and adaption protocol(L2CAP). The protocol is based on the ETSI standard TS 07.10.
7. OBEX: It is short for Object Exchange. It is a communication protocol to exchange objects between 2 devices.
8. WAP: It is short for Wireless Access Protocol. It is used for internet access.
9. TCS: It is short for Telephony Control Protocol. It provides telephony service. The basic function of this layer is call control (setup & release) and group management for the gateway serving multiple devices.
10. Application layer: It enables the user to interact with the application.

Types of Bluetooth

Various types of Bluetooth are available in the market nowadays. Let us look at them.

• In-Car Headset: One can make calls from the car speaker system without the use of mobile phones.
• Stereo Headset: To listen to music in car or in music players at home.
• Webcam: One can link the camera with the help of Bluetooth with their laptop or phone.
• Bluetooth-equipped Printer: The printer can be used when connected via Bluetooth with mobile phone or laptop.
• Bluetooth Global Positioning System (GPS): To use GPS in cars, one can connect their phone with car system via Bluetooth to fetch the directions of the address.

Advantage:

• It is a low-cost and easy-to-use device.
• It can also penetrate through walls.
• It creates an Ad-hoc connection immediately without any wires.
• It is used for voice and data transfer.

Disadvantages:

• It can be hacked and hence, less secure.
• It has a slow data transfer rate: of 3 Mbps.
• It has a small range: 10 meters.
• Bluetooth communication does not support routing.
• The issues of handoffs have not been addressed.

Applications:

• It can be used in laptops, and in wireless PCs, printers.
• It can be used in wireless headsets, wireless PANs, and LANs.
• It can connect a digital camera wirelessly to a mobile phone.
• It can transfer data in terms of videos, songs, photographs, or files from one cell phone to another cell phone or computer.
• It is used in the sectors of Medical health care, sports and fitness, Military.

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What is Bluetooth & How It Work

Bluetooth is the technology that allows electronic devices to communicate with each other directly. It uses radio waves that are both transmitted and received by the devices in connection with each other.

Bluetooth is something that has changed a lot over my years as a network engineer, and what it is today is very different from what it was 10 years ago.

I will now explain what Bluetooth is and how it works, so keep reading.

What is Bluetooth

Bluetooth is a wireless communications technology that allows high-speed, low power, wireless transmissions between electronic devices in short distances using a standardized protocol.

Or in more simple words. Bluetooth is the technology that allows for communication between electronic devices.

Bluetooth is mostly used for connecting things like wireless headphones to your phone or a wireless mouse to a computer. It should also not be confused with a Wi-Fi signal. [1]

The difference between Wi-Fi and Bluetooth is that Wi-Fi is much stronger and comes from your router. And even if devices can connect with each other through Wi-Fi it’s not the same as Bluetooth.

This is because Bluetooth is a direct connection between the devices while Wi-Fi uses the router as an interlink.

How Bluetooth Works

Bluetooth works very similarly to how Wi-Fi signals and radio signals work. Through radio waves.

Bluetooth uses a band of 79 different frequencies (channels) which range from 2,4-2,485 GHz. This frequency interval is shared with industrial, scientific, and medical gadgets. [2]

But this won’t be a problem for you when you use Bluetooth. This is because the class 2 type Bluetooth that exists in consumer devices such as phones and computers only have a range of around 10 m.

Other types of Bluetooth are class 1 and 3. Class 1 is used in industry and has a range of around 100m and class 3 is rarely used because of its short range of 1 m. [3]

Furthermore, the Bluetooth signal is not just one frequency. It can change its frequency, as much as 1600 times every second. This is to keep the signal strength and minimize interference in radio crowded areas.

Bluetooth Networks

A Bluetooth network is called a piconet and uses a master/slave system to control the data flow.

In this system, one “master” device (often a phone or a computer) can connect to up to seven other devices. These will get the role of slaves (slave devices are often wireless earphones, mice, or keyboards). Slave devices can only connect to one master at a time. [4]

The master’s role is to coordinate data transfer in the piconet (Bluetooth network). It can send or request data from any of its slaves. In addition, slaves are not allowed to communicate with each other in the piconet.

Every electronic device with Bluetooth has a different address. This is important because in a house there are often a lot of devices that use Bluetooth to communicate with each other.

An address makes it possible for the device to know if a Bluetooth signal is meant for it or not.

There are three steps in the connection process between two devices that establish a Bluetooth connection. These steps are:

1. Inquiry – If two devices have no information about each other one of them must send an inquiry request. The other device then responds with its address and name and what kind of hardware it is.

1. Connecting – Here the two devices form a Bluetooth connection.

1. Connection – After the devices have connected they enter a connection state with each other. The device can either be actively connected with each other or passively connected.

An active connection is when the connected devices constantly talk to each other. While passive is when they talk to each other periodically, like once every 1 second.

Device Bonding

Device bonding is when two devices remember each other. Bonded devices automatically establish a connection with each other if they are in range. An example is a car, which often connects with your mobile when you start it.

To create these bonds the devices go through a process called pairing. During pairing the two devices usually follow the normal connection process.

But instead of forgetting the device when they disconnect from each other. The devices’ data gets stored in memory. Furthermore, they also save a shared secret code that allows them to reconnect with each other in the future.

Why It’s Called Bluetooth

The name Bluetooth comes from the Danish king Harald Blåtand. He was king in the 900s and is most known for uniting Denmark and part of Norway into a kingdom. His name Blåtand is directly translated to Bluetooth. The belief is that he got this name from a rotten tooth that appeared blue.

The reason Bluetooth is named after him was that he united Denmark and Norwegian. Just like Bluetooth unites devices with each other. [5]

It is also here it has got its symbol from. The symbol consists of Harald Blåtands initials, H and B. But instead of using normal letters, it uses Nordic runes.

Bluetooth Security

Wireless connections will always be less secure than wired connections. This is because wireless connections are much easier to find and expose. But this makes Bluetooth far from unsecured.

The biggest security feature Bluetooth has is its short range. It makes it much harder for hackers to access it, compared to your internet connection for example. This is why the only real place Bluetooth hacking takes place is in public places with a lot of devices. [6]

In general, Bluetooth security is not something to worry about. And if you want to be extra safe you can set your device on hidden mode. Then will no other Bluetooth device be able to find it.

Pros & Cons With Bluetooth

There are of course some cons with Bluetooth, but they are for the most part overshadowed by the pros. Here they are;

Pros:

• New versions consume little battery.
• Very practical (doesn’t need cables).
• Secure.
• Allows for wireless hardware.

Cons:

Bottom Line

I hope this article has shed some light on how Bluetooth works and what it is. As well as make you realize how often most of us use Bluetooth in our everyday activities.

If you want to learn more about network technology check out my Router vs Modem – What’s the difference.

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