Bluetooth
Bluetooth (BT) is a medium, a technology that replaced the swarm of tangled wires and made wireless data transfer possible for short range. It is a medium that requires less power and has a lower hardware cost. This technology is supported and used on many devices like mobile phones, smartphones, speakers, headphones, medical devices, and advanced electronic systems. This medium made the lives of people easier and faster. Nowadays, IOT (short for Internet of Things) is gaining momentum and BT is one of the core parts of IOT.
In 1989 Ericsson, which is a Swedish multinational networking and telecommunications company, started the development of “short link” (later named as Bluetooth). By 1997, Ericsson developed a workable solution for developing wireless headsets. Also, in 1997 IBM and Ericsson collaborated to integrate Ericsson’s mobile phones into IBM’s “ThinkPad” notebook but the integration failed because they were unable to reach power requirements. But they integrated Ericsson’s “Short-Link” technology on both devices.
As both products were quite unpopular at that time, they made “Short-Link” an open industry standard. After seeing the potential of “Bluetooth”, Intel, Nokia, and Toshiba joined with IBM and Ericsson and formed a Special Interest Group (SIG) in May 1998, they launched Bluetooth SIG to standardize this technology and create new advancements.
The first BT device was launched in 1999 which was a hands-free mobile headset used with mobile phones. Then, in 2001 Ericsson launched the first BT mobile phone T39 and after that, IBM launched its first BT notebook “ThinkPad A30” in October 2001.
This technology is a widely used medium in electronic devices because of its advantages like lower power consumption, lower manufacturing costs, reliability, and security. This wireless communication medium uses a frequency band between 2.400 GHz to 2.4835 GHz which is a globally unlicensed short-range radio frequency band. The maximum data transfer speed is 3 Mbps.
Also, it uses Gaussian Frequency Shift Keying modulation which uses a frequency hopping technique to prevent interference in the 2.4 GHz band and leads to smoother data transition. However this technology has some limitations in comparison to Wi-Fi as BT has a limited range of 10 meters, so it restricts the data transfer for short distances, also the data transfer speed is slower than Wi-Fi and it is more prone to interference from other BT devices as 2.4GHz is a busy band.
The SIG has launched different versions of BT wireless medium over the years like Version 1.0 (1999), 2.0 + EDR (2004), 3.0 + HS (2009), 4.0 (2010) and 5.0(2016).
Bluetooth 1.0:
Launch Year: 1999
Key Features: Wireless connectivity between electronic devices for short-range communications between them.
Limitations: Limited data transfer rates, primarily suited for audio transmission and basic data synchronization.
Bluetooth 2.x +EDR:
Launch Year: 2004
Key Features:
- Enhanced Data Rates (EDR) for faster data transfer and speed up to 3 Mbps.
- Improved power consumption and security features.
- Support for pairing devices using Secure Simple Pairing (SSP) and Extended Inquiry Response (EIR). The EIR helps in the discoverability of nearby BT devices by sending Inquiry packets to other devices.
Bluetooth 3.0:
Release Date: 2009
Key Features:
- Introduction of BT High Speed (HS) for faster data transfer rates (up to 24 Mbps).
- Enhanced power efficiency through Enhanced Power Control (EPC).
- Supports simultaneous operation with Wi-Fi through AMP (Alternate MAC/PHY).
Bluetooth 4.x:
Release Date: 2010
Key Features:
- Bluetooth Low Energy (BLE) was introduced for ultra-low power consumption, enabling long battery life for devices.
- Classic Bluetooth and BLE coexistence for dual-mode devices.
- Improved security with Secure Connections and LE Privacy features.
- Enhanced data packet format (6 Mbps).
Versions within Bluetooth 4.x:
- Version 4.0: Initial release with BLE support.
- Version 4.1: Improved coexistence with LTE, standardized GATT (Generic Attribute Profile).
- Version 4.2: Increased data transfer speeds (2.1 Mbps), enhanced privacy features, and support for IPv6.
- Version 4.3: Minor updates and bug fixes.
Bluetooth 5:
Release Date: 2016
Key Features:
- Four times longer range compared to BT 4.x.
- Doubled data transfer speeds (up to 2 Mbps).
- Eight times broadcast messaging capacity.
- Improved coexistence with other wireless technologies.
- Enhanced security features with LE Secure Connections.
Versions within BT 5:
- Version 5.0: Initial release with major range and speed improvements.
- Version 5.1: Introduction of direction-finding feature for location-based services.
- Version 5.2: Enhanced audio quality with LE Audio, improved support for IoT devices, and updated LE Advertising extensions.
- Version 5.3: On July 13, 2021, the BT SIG released version 5.3, which brings four new enhancements and removes one extension from the core specification:
- Periodic Advertising Enhancement
- Encryption Key Size Control Enhancement
- Connection Subrating
- Channel Classification Enhancement
- Removal of the Alternate MAC and PHY (AMP) Extension
Each new version of BT builds upon the previous ones, introducing enhancements to range, speed, power consumption, security, and functionality to meet the evolving needs of wireless communication in various applications. And the applications of BT are also increasing in proportion to its versions. BT is being used as a medium in devices like wearable health monitors, Medical Implants and Prosthetics, Headphones, smart watches, smartphones, IoT devices for home automation (like door locks, Electrical Devices and so on), and other electronic devices.
Future Aspects
In Future, the SIG is going to launch Version 6.0 and the expected features are, while specific details about BT 6.0 are not available, it is expected to continue the trend of improving range, speed, and efficiency while introducing new features to support emerging use cases such as IoT, wearables, and smart home devices.