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Evolution of Bluetooth

You or someone you know has most likely listened to music using a Bluetooth-enabled gadget. Most likely, you've used a Bluetooth headset or earpiece. Perhaps you've used one to track the progress of your workout routine or to locate a misplaced cell phone.


Bluetooth technology has advanced dramatically over the previous 20 years. It can now be found in practically all of our electronic devices, including smartphones, headphones, speakers, smartwatches, computers, and various other devices. It has become a necessary component of some people's daily lives.


Bluetooth 5, the most recent version, has been a hot issue among developers and customers due to its promising internet of things (IoT) experience and advancements in speed, range, and data capacity.


Have you ever considered how this pervasive technology has evolved?

What exactly is Bluetooth technology, and how did it come to be?


Bluetooth is a short-range wireless technology for transferring data between devices.

Bluetooth communication operates at frequencies ranging from 2.4 to 2.485 gigahertz (GHz). It is based on the packet-based protocol, which entails splitting data into packets and broadcasting each packet on 79 specified Bluetooth channels.


Bluetooth and its variants have now become synonymous with short-range wireless technology, with more than 8.2 billion gadgets manufactured by over 30,000 Bluetooth SIG members. It is a low-power wireless communication technology that allows audio to be streamed, data to be transferred, and information to be broadcast between devices.


Bluetooth and Bluetooth Low Energy (BLE) are wireless data transfer systems that work over short distances. Small consider devices that connect to customers' phones and tablets typically employ the technology. Many speaker systems, for example, utilise the technology.


Bluetooth Low Energy is a type of Bluetooth that uses less power than conventional Bluetooth and is used in hardware such as fitness trackers, smart watches, and other connected devices to wirelessly communicate data without draining a user's phone's battery.


BLE has only recently begun to gain traction. Nokia first presented the technology in 2006, but it wasn't until 2010 that it became part of the Bluetooth standard. BLE is now supported by the majority of smartphone and computer manufacturers, as well as the majority of major operating systems, including Windows 8, OS X, Linux, Windows Phone, Android, and iOS.


Basic/Enhanced Data Rate (BR/EDR) and Low Energy Bluetooth are the two types of Bluetooth (LE).


The Bluetooth Classic radio, also known as Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR), is a low-power radio that transmits data across 79 channels in the unlicensed 2.4GHz industrial, scientific, and medical (ISM) frequency spectrum. Bluetooth Classic is primarily used to provide wireless music streaming and has become the standard radio protocol underpinning wireless speakers, headphones, and in-car entertainment systems. It supports point-to-point device communication. Data transfer applications, such as mobile printing, are also possible with the Bluetooth Classic radio.


Low-energy Bluetooth (LE)


The Bluetooth Low Energy (LE) radio is made to run on very little power. The Bluetooth LE radio transmits data over 40 channels in the 2.4GHz unlicensed ISM frequency region, giving developers a lot of freedom to create devices that match their market's specific connectivity needs. Bluetooth LE offers a variety of communication topologies, including point-to-point, broadcast, and, most recently, mesh, allowing Bluetooth to assist the establishment of dependable, large-scale device networks. While Bluetooth LE was originally developed for device communications, it is now widely employed as a device positioning technology to meet the growing demand for high-accuracy indoor location services. Bluetooth LE now provides Bluetooth® Direction Finding and, soon, high-accuracy distance measurement, in addition to simple presence and proximity features.


The First Bluetooth system in cars:


Chrysler was one of the first automakers to take a gamble on the new technology, seeing a market for hands-free communication long before distracted driving became widespread. In 1999, they released the first Bluetooth-enabled device (for the 2000 model year). Chrysler was one of the few manufacturers in North America to offer drivers with its UConnect interface until 2004. In today's world, having Bluetooth functionality in a car is nearly a requirement. With new rules enacted to combat distracted driving, having a hands-free phone connection has become critical. Not to mention, thanks to simple music streaming straight from the phone, the ancient in-car CD player and even the once-coveted USB and audio-in connectors have become obsolete.


Evolution of Bluetooth Technology:

2004 - Bluetooth 2.0 + EDR

While the first Bluetooth-enabled phone was released in 2000, the technology became much more widely available in 2004. It's possible that this was because the version published that year made it easier for people to use the technology in their daily lives.

The addition of Enhanced Data Rate (EDR) technology was the most prominent feature of version 2.0. This theoretically allows users to increase data transfer speeds to 3 megabits per second (Mbit/s). However, it might be increased to 2.1 Mbit/s in actuality.

Compared to the previous iteration, power consumption was also reduced by half. However, encryption and EDR were both optional in this version and could even be turned off.


2007 - Bluetooth 2.1

The addition of Secure Simple Pairing was the most crucial feature of this version (SSP). As you may expect, our method simplified and secured the pairing process. Man-in-the-middle attacks became more complicated with SSP because all connections had to be encrypted. Third parties intercept and relay messages between two parties that believe they are speaking directly to each other in these attacks.

Another major feature of this version was sniff subrating. By limiting the active-duty cycle of Bluetooth devices, this function was developed to extend the battery life of inactive devices the majority of the time, such as keyboards and headsets.

Finally, the addition of Extended Inquiry Response (EIR) improved the filtering of devices that surfaced during connection scanning.


2009 - Bluetooth 3.0 + HS

The high-speed data transfer was a crucial feature of this version. It might attain data speeds of up to 24 Mbit/s with the help of an 802.11 Wi-Fi radio, which is nearly 11 times quicker than just three years ago. It sent vast amounts of data over a faster 802.11 link while still using Bluetooth radio for discovery, connection, and configuration.

A Wi-Fi radio, combined with an improved power control feature, allowed for more efficient power usage. Although using a Wi-Fi radio consumes more power, it is usually turned off until required data transfer.

This version of the gadget was also made more responsive by integrating unicast connectionless data (UCD). Near-field communication was also possible with this version (NFC).


2010 - Bluetooth 4.0

The highlights of this version were improved connectivity and range and the addition of a low-energy protocol. Nokia was working on the concept under the name Wibree before the Bluetooth SIG accepted it in 2010.

Bluetooth 4.0, also known as Bluetooth Smart, was created to routinely transmit data to devices, such as smartphones while conserving battery. This allowed for the use of coin-sized batteries, allowing for a novel means of collecting data from sensors like heart rate monitors and thermometers. Companies in the health and fitness industry have taken advantage of the new functionality by developing a variety of devices that can monitor and communicate physical data to a smart device.

Aside from Bluetooth Low Energy (BLE), this version added the Generic Attribute Profile (GATT), which is used to provide the device's profile and Security Manager (SM) services with AES encryption.

Dual-mode and single-mode solutions were possible with Bluetooth 4.0 chip designs. The first is used to produce a 100 per cent pure BLE device, while the second uses an existing Classic Bluetooth controller to implement the BLE protocol. NFC connectivity was also possible with this version.


2013 - Bluetooth 4.1

This version was released in 2013 with minor hardware, speed, and range adjustments. However, there were some important advancements on the software side.

With the Internet of Things (IoT) having such a large influence today, Bluetooth 4.1 focuses on creating the basis for IoT devices. Using its new protocol, it could connect gadgets that would otherwise be out of range through the cloud.

This version's ability to coexist with LTE radios was another upgrade. Bluetooth and LTE did not get along before this version was introduced, resulting in difficulties like poor performance and battery waste when they were used together.

Developers and manufacturers were also given additional control over connections in this version. Bluetooth 4.1 allows users to customise reconnection intervals and disconnect criteria rather than having a fixed timeout period. Bluetooth devices were treated "uniquely" as a result, and they were able to control better their own power as well as the power of a linked device.

Additionally, while prior Bluetooth versions needed an intermediary host between peripheral devices, the 4.1 version allowed any device to act as both a peripheral and a hub at the same time. As a result, peripherals could communicate with one another without the requirement for a host. If you were to utilise a smartphone, pedometer, and smartwatch, for example, the smartwatch and pedometer could interact directly with each other without the need for the smartphone.


2014 - Bluetooth 4.2

Bluetooth SIG announced this Bluetooth version in 2014 to finally eliminate range restrictions by allowing devices to use Internet Protocol version 6 (IPv6) for direct internet access. As a result, sensors and intelligent devices might directly send data over the internet.

Another appealing feature of this edition was its improved speed and privacy. Bluetooth 4.2 doubled the data packet capacity of the technology, making it 2.5 times faster than the previous version. This Bluetooth version's security improvements made it more difficult to track your device without your permission.


2016 - Bluetooth 5

Bluetooth 5 is essentially a supercharged version of prior Bluetooth generations. It's all about the Internet of Things, as well as speed, range, and data capacity.

The SIG officially endorsed it in December 2016, intending to improve wireless technology by expanding the capability of Bluetooth for IoT. This version shows a continued shift away from the app-to-device connection approach and toward connecting devices directly over the internet.

Aside from the IoT enhancements, Bluetooth 5 is two times faster, has a four-fold increase in range, and has an eight-fold increase in capacity. Data transfers and software upgrades are faster with twice the speed, and devices are more responsive.

This version's revised specs state that you can be up to 120 metres away from it. You won't have to worry about being too close to a device to stay connected with a longer range. It also has a lot of flexibility, provides lossless and secure communication, and is low-energy. This version also allows for peaceful cohabitation with various wireless technologies, becoming increasingly crucial as we move deeper into the IoT world.

Bluetooth IEEE Standard

Bluetooth is a wireless technology that is based on the IEEE 802.15 standard. For data transfer, Bluetooth uses UHF radio waves. The technology was initially specified as IEEE 802.15.1, but that standard is no longer in use by the IEEE.


Now, the Bluetooth Special Interest Group (Bluetooth SIG) is the standards body in charge of developing Bluetooth standards as well as licensing Bluetooth technology and trademarks to manufacturers.

A company must join the Bluetooth SIG in order to become a licensee. The SIG also oversees the Bluetooth SIG Qualification programme, which is a certification process that is necessary for every product that uses Bluetooth wireless technology and is a requirement of the Bluetooth intellectual property license. The SIG's main responsibilities include publishing Bluetooth specifications, protecting Bluetooth trademarks, and spreading the word about Bluetooth wireless technology.


The architecture of Bluetooth Technology (IEEE 802.15 protocol)


Piconet Network

Piconet is a wireless network that consists of one primary node, the master node, and seven energetic subsidiary nodes, referred to as slave nodes. As a result, we can say that there are a total of eight active nodes arranged at a distance of ten metres. The message transmission between these two nodes can be one-to-one or one-to-many. Only communication between master and slave is feasible, but communication between slave and slave is not. There are also 255 secondary nodes, which are parked nodes. These won't be able to communicate until the state is changed to active.


Scatternet Network

The Scatternet Network can be created using a variety of piconets. There is a slave on one piconet that functions as a master, but it can also be termed main in other piconets.

As a result, this sort of node receives a message from the master in one piconet and sends it to its slave in another piconet, where it operates as a slave. As a result, this type of node is known as a bridge-node. A station cannot be master in two piconets.


Bluetooth network technology establishes a personal area network by wirelessly connecting mobile devices over a short distance (PAN). Instead of following the usual OSI or TCP/IP models, the Bluetooth architecture has its own separate paradigm with a stack of protocols.


The architecture is multilayered. The physical layer, data link layer, middleware layer, and application layer are the four layers that make up the Bluetooth standard.



Physical Layer - Includes Bluetooth radio and Baseband (also in the data connection layer)


Radio - It is a physical layer protocol that establishes the physical structure and criteria for radio wave transmission. The air interface, frequency bands, frequency hopping parameters, and modulation algorithms are all defined in this document.


Baseband - It is a protocol that uses the radio protocol's services. The addressing scheme, packet frame format, timing, and power control methods are all defined in this document.


Data Link Layer (L2CAP) - It includes Baseband, Link Manager Protocol (LMP), and Logical Link Control and Adaptation Protocol.


LMP (Link Manager Protocol) - It establishes and maintains logical relationships between Bluetooth devices to enable communication. Other functions of LMP - Device authentication, message encryption, and packet size negotiation.


L2CAP (Logical Link Control and Adaptation Protocol) - It adapts the upper layer frame format to the baseband layer frame format. L2CAP supports both connection-oriented and connectionless services.


Middleware Layer - This comprises the RFComm protocol, accepted protocols, SDP, and AT commands, among others. Radio Frontend Component is abbreviated as RFComm that provides a serial interface with WAP.


Adopted Protocols - Protocols that have been adopted from standard models are referred to as Point-to-Point Protocol (PPP), Internet Protocol (IP), User Datagram Protocol (UDP), Transmission Control Protocol (TCP), and Wireless Application Protocol are some of the most widely utilised Bluetooth protocols (WAP).


SDP (Service Discovery Protocol) - It is a protocol for establishing a connection between competing Bluetooth devices by handling service-related inquiries such as device information.


AT Commands - It is a set of ATtention commands that are used to change the default settings of Bluetooth module.


The Application Layer - Includes the application profiles that enable the user to interact with the Bluetooth applications.


The Future of Bluetooth

Bluetooth's encompassing benefits drive IoT device manufacturers to include Bluetooth technology into their products. Bluetooth's ability to locate devices by following the direction and strength of signals was quadrupled when the technologies of Radio Direction Finding (RDF) and Received Signal Strength Indicator (RSSI) were added. This allows complex Bluetooth apps to be integrated into many IoT devices.


Bluetooth-enabled smart wearables, such as smartwatches, activity bands, hearing aids, and other gadgets, are expected to be made and marketed more than 400 million units globally by 2024. Furthermore, even though Wi-Fi devices dominate all other smart home appliances and gadgets, Bluetooth devices are expected to contribute 13% to market development.


Factors that bolstered Bluetooth's appeal for IoT devices

Bluetooth's most recent version included a comprehensive set of capabilities tailored to the needs of IoT devices, allowing for scalable performance.


Exceptional Speed: Bluetooth version 5 increased data transfer speeds to 2Mbps, which is twice as fast as the previous version. Furthermore, embedded Bluetooth gateways allowed the gadgets to communicate in real-time. Bluetooth might transfer massive amounts of data if it could reach 2Mbps. However, as the data transmission speed increases, the range of the receiver signal decreases. Despite this, the requisite data-exchange turnaround time for IoT devices is met at this pace.


Excellent Range: Bluetooth 5 uses Forward Error Correction (FEC) technology to protect the receiver from external interference and capture error-free data. As a result, the revised version provides a four-fold signal range. Even if an error occurs, it aids in the recovery of the original dataset by utilising data redundancy. The long-range modes provide network coverage of up to 800 metres.


Furthermore, the signal range can be expanded by utilising mesh networks while consuming minimal power. It also allows users to connect tens of thousands of devices.


Expanded Connectivity: To link Bluetooth devices, the advertising and scanning processes need to take place simultaneously. The scanning device locates the advertised pair by detecting the broadcasted packets. Unlike previous versions, Bluetooth 5's Extended Advertising model allows devices to send data packets of up to 255 bytes. Furthermore, by adopting beacon technology to transmit signals via BLE, the broadcasting capacity increases by 800%, implying an increased connection.


Detection Accuracy: Bluetooth 5 provides devices with incredible proximity detection and location capabilities. Devices can now detect the location of linked devices with a 1cm precision. Bluetooth devices can determine the direction of signals using Radio Direction Finding technology. As a result, the most precise position may be determined using triangulation techniques.


Conclusion

The projected market expansion of Bluetooth-enabled IoT devices suggests a massive technological transition. It makes people's lives easier and aids in automating various operations. IoT devices will be used to protect industries and large human settlements such as flats and houses. Unsurprisingly, Bluetooth technology is the best way to connect all of these devices and applications accurately. There's no indication of Bluetooth 6.0 yet, but a new wireless technology called Ultra-Wide Band, or UWB, is gaining steam. It has the capacity to identify the direction of a connected device and covers high-speed data transfer usage cases that Bluetooth abandoned many years ago (Bluetooth can, by the way, too). Bluetooth and UWB coexist for the time being, but it's not impossible that the two may conflict in the future.


References

https://www.geeksforgeeks.org/bluetooth/

https://www.tutorialspoint.com/the-bluetooth-protocol-architecture

https://en.wikipedia.org/wiki/Bluetooth

https://www.dailyexcelsior.com/evolution-of-bluetooth-technology/

https://www.gsmarena.com/flashback_a_brief_history_of_bluetooth-news-49119.php

https://www.researchgate.net/figure/A-brief-history-of-Bluetooth_fig1_333528241

https://straussandwagner.com/blogs/news/a-brief-history-of-bluetooth-and-its-many-versions

https://www.mybluetoothreviews.com/a-brief-history-of-bluetooth-technology/

https://ma4p.com/831/flashback-a-brief-history-of-bluetooth/

https://www.researchgate.net/figure/IEEE-802151-Bluetooth-BR-EDR-protocol-stack_fig22_268769071