The Bluetooth Special Interest Group released the Bluetooth 5.0 standard on June 16, which further improves upon the previous version, attracting widespread user attention.
Most people are familiar with Bluetooth, a radio technology that supports short-range communication (generally within 10m) between devices. Before Wi-Fi transmission technology appeared, Bluetooth was widely used for wireless information exchange between various connected devices, dominating the transmission market for a considerable time.
It is important to note that Bluetooth technology itself has also been evolving, from V1.1 to V2.0 to V4.2, and now the latest version V5.0, continuously optimizing and enhancing its capabilities. Especially with the release of the Bluetooth 5.0 standard on June 16, it has garnered significant attention from users.
So what is Bluetooth?
Bluetooth technology is a cutting-edge open wireless communication standard that enables wireless connections between desktop computers, laptops, portable devices, PDAs, mobile phones, camera phones, printers, digital cameras, headsets, keyboards, and even computer mice over short distances. By utilizing Bluetooth technology, communication between mobile communication terminal devices can be effectively simplified, as can communication between devices and the Internet, making data transmission faster and more efficient.
Bluetooth adopts a decentralized network structure, along with fast frequency hopping and short packet technology, supporting point-to-point and point-to-multipoint communication, operating in the globally recognized 2.4GHz ISM (Industrial, Scientific, Medical) frequency band. Its data rate is 1Mbps, and it uses time-division duplex transmission to achieve full-duplex communication.
The Bluetooth protocol stack can be divided into four layers based on its functions: Core Protocol Layer (HCI, LMP, L2CAP, SDP), Cable Replacement Protocol Layer (RFCOMM), Telephony Control Protocol Layer (TCS-BIN), and Optional Protocol Layer (PPP, TCP, IP, UDP, OBEX, IrMC, WAP, WAE).
In simple terms, Bluetooth technology enables wireless communication between various digital devices, making the clutter of cables on desks a thing of the past. With Bluetooth wireless technology, you can easily connect your computer to portable devices, mobile phones, and other peripheral devices—wirelessly connecting within a distance of 9 meters (30 feet).
Compared to other wireless technologies such as infrared, wireless 2.4G, and Wi-Fi, Bluetooth has many advantages, including comprehensive encryption measures, stable transmission processes, and a wide range of compatible devices. Especially today, as authorization thresholds gradually lower, Bluetooth technology is becoming widely adopted across all digital devices. However, the journey of Bluetooth has not been flawless; the evolution from 1.0 to 4.2 and now to 5.0 has been remarkable.
The Evolution and Development History of Bluetooth Versions
Before 5.0, Bluetooth underwent several version evolutions, primarily 1.1, 1.2, 2.0, 2.1, 3.0, 4.0, 4.1, and 4.2.
Bluetooth 1. Standard
1.1 was the earliest version, with a transmission rate of approximately 748~810kb/s. Due to its early design, it was susceptible to interference from products operating on the same frequency, affecting communication quality.
Bluetooth 1.2 Standard
1.2 also had a transmission rate of only 748~810kb/s but added an improved anti-interference frequency hopping function.
Bluetooth 2.0 Standard
2.0 is an improved version of 1.2, with a transmission rate of approximately 1.8M/s~2.1M/s. It began to support duplex mode—allowing voice communication while simultaneously transmitting files/high-quality images. The 2.0 version also supported stereo operation.
Bluetooth 2.1 Standard
On August 2, 2007, the Bluetooth Special Interest Group officially approved the Bluetooth 2.1 specification, known as “Bluetooth 2.1+EDR,” available for future devices. Products contemporary with the 2.0 version still occupy a significant share of the Bluetooth market, with the major improvement being a standby time increased by more than twice, with no fundamental changes in technical standards.
Bluetooth 3.0 Standard
On April 21, 2009, the Bluetooth Special Interest Group officially announced the next-generation standard specification “Bluetooth Core Specification Version 3.0 High Speed” (Bluetooth Core Specification 3.0). The core of Bluetooth 3.0 is “Generic Alternate MAC/PHY” (AMP), a new alternating radio frequency technology that allows the Bluetooth protocol stack to dynamically select the correct radio frequency for any task.
Bluetooth 3.0’s data transmission rate increased to about 24Mbps (allowing the use of 802.11 Wi-Fi for high-speed data transmission when needed). In terms of transmission speed, Bluetooth 3.0 is eight times faster than Bluetooth 2.0, making it easy to transfer data between devices such as camcorders to HDTVs, PCs to PMPs, and UMPCs to printers, although both parties must meet this standard for functionality.
Bluetooth 4.0 Standard
The Bluetooth 4.0 specification was officially released on July 7, 2010. The significance of the new version lies in its low power consumption while enhancing device compatibility among different OEM manufacturers and reducing latency. The theoretical maximum transmission speed remains 24Mbps (i.e., 3MB/s), with an effective coverage range expanded to 100 meters (previous versions had a range of 10 meters). This standard chip has been widely adopted in many mobile phones and tablets, such as Apple’s The New iPad and iPhone 5, Meizu MX4, HTC One X, etc.
Bluetooth 4.1 Standard
Bluetooth 4.1 was released on December 6, 2013. If data is transmitted simultaneously with LTE radio signals, Bluetooth 4.1 can automatically coordinate the transmission information of both, theoretically reducing interference from other signals on Bluetooth 4.1. Improvements include enhanced connection speed and increased intelligence, such as reducing the reconnection time between devices. This means that if a user steps out of Bluetooth 4.1’s signal range and disconnects for a short period, when they return to the signal range, the device will automatically reconnect, with a response time shorter than that of Bluetooth 4.0. The final improvement is increased transmission efficiency; if a user connects multiple devices, such as several wearable devices, information can be transmitted instantly to the receiving device.
Additionally, Bluetooth 4.1 provides developers with more flexibility. This change may not significantly impact average users, but it is crucial for software developers, as Bluetooth must support simultaneous connections to multiple devices in response to the rising popularity of wearable devices.
Bluetooth 4.2 Standard
On December 4, 2014, the latest Bluetooth 4.2 standard was announced. The publication of Bluetooth 4.2 not only improved data transmission speed and privacy protection but also allowed devices to connect directly to the Internet via IPv6 and 6LoWPAN.
Firstly, the speed aspect has become much faster. Although Bluetooth 4.1 had already made significant improvements, it was still far from meeting user demands, especially compared to Wi-Fi. The Bluetooth 4.2 standard improves the capacity of Bluetooth Smart data packets, allowing them to hold approximately ten times the amount of data compared to previous versions, with the data transmission speed between two Bluetooth devices increasing by 2.5 times.
Secondly, the enhancement of privacy protection has received positive feedback from many users. It is known that Bluetooth 4.1 and earlier versions had certain vulnerabilities regarding privacy security—once connected, they would automatically reconnect without requiring further confirmation, making it easy to leak privacy. Under the new Bluetooth 4.2 standard, Bluetooth signals must obtain user permission to connect or track user devices; otherwise, they cannot connect or track user devices.
Of course, the most anticipated feature is the new version’s ability to connect to the Internet via IPv6 and 6LoWPAN. The Bluetooth Special Interest Group had already begun attempts to connect with Bluetooth 4.1, but due to previous transmission rate limitations and incompatibility with network chips, this function was not fully realized. According to the Bluetooth Special Interest Group, the new Bluetooth 4.2 standard can now connect directly to the Internet via IPv6 and 6LoWPAN. It is believed that once IPv6 and 6LoWPAN are widely adopted, this feature will attract even more attention.
Additionally, it is worth mentioning that some functions of Bluetooth 4.2 can be obtained through software upgrades for older Bluetooth adapters, but not all features are accessible. The Bluetooth Special Interest Group stated: “Privacy features may be obtained through firmware upgrades, depending on the manufacturer’s installation and activation. Speed enhancements and data packet expansion features will require hardware upgrades.” As of now, Bluetooth 4.0 remains the most commonly used standard among consumer devices, although mobile platforms such as Android Lollipop have begun to add native support for Bluetooth 4.1 and Bluetooth 4.2 standards.
Bluetooth 5.0 Standard
On June 16, 2016, the Bluetooth Special Interest Group (SIG) officially released the fifth generation of Bluetooth technology (Bluetooth 5.0), which not only doubles the speed but also quadruples the distance while optimizing the underlying functionality for IoT.
In terms of performance, the Bluetooth 5.0 standard has a transmission speed that is twice that of the previous 4.2LE version, and the effective distance is four times that of the previous version, meaning the theoretical effective working distance between Bluetooth transmitting and receiving devices has increased to 300 meters.
Additionally, Bluetooth 5.0 allows data to be received from beacons without pairing, such as advertisements, beacons, location information, etc., with an 8-fold increase in transmission rate. Furthermore, the Bluetooth 5.0 standard is optimized for IoT, aiming to serve smart homes with lower power consumption and higher performance.
The Bluetooth Special Interest Group states that there are currently over 8.2 billion Bluetooth devices globally. It is expected that the Bluetooth 5.0 standard will officially launch by the end of 2016 or early 2017, and flagship smartphones equipped with Bluetooth 5.0 chips will be released in 2017, with Apple reportedly among the first manufacturers to use this technology.
Bluetooth 2016 Technology Blueprint
In 2016, the Bluetooth Alliance focused on the layout of the Internet of Things (IoT), primarily in three directions, including enhancing the transmission distance of Bluetooth low energy by four times, increasing traditional Bluetooth transmission to 2Mbit/s, and supporting the long-awaited Bluetooth Mesh (mesh networking) for the IoT industry.
The extension of Bluetooth low energy and support for Bluetooth Mesh are significant layouts for the IoT, making the advantages of extended distance more practical for applications in automation, industrial control, and smart homes. The greatest advantage of supporting Mesh is that Bluetooth devices can connect not only in a point-to-point manner but also among themselves, thus extending the management distance of Bluetooth.
Moreover, the 100% increase in transmission speed not only increases bandwidth but also allows Bluetooth to be used in applications that emphasize low latency, such as medical devices, enabling more timely information transmission and management due to the new Bluetooth standards announced this year.
In addition to IoT and applications for connecting devices, Bluetooth technology has seen more applications in recent years, especially as beacon technology is changing positioning and services. By replacing barcodes with beacon technology, users can easily obtain relevant information, and simultaneously use Bluetooth technology for indoor positioning services, applicable in department stores or stations for indoor navigation and finding product locations; additionally, with the extended distance and the upcoming introduction of Mesh, Bluetooth is expected to bring more changes and flexibility to automation solutions.
Beyond the new development goals mentioned above, the Bluetooth Alliance also announced a new technology called TDS (Transport Discovery Service) in March. This technology allows Bluetooth to search for and initiate available wireless links within range, detecting nearby wireless devices and services, enabling users to turn off high-power-consuming technologies in their devices and turn them back on when needed. The Bluetooth Alliance hopes this technology will improve energy management in IoT environments.
Bluetooth Chip Manufacturers
1. CSR (acquired by Qualcomm) Headquarters: UK Applications: Bluetooth headsets.
2. Broadcom (acquired by Avago) Headquarters: USA Main business: Wireless semiconductor design and manufacturing, computing and networking devices, digital entertainment, broadband access products, system-on-chip and software solutions for mobile devices.
3. Infineon Headquarters: Germany Main business: Automotive system chips, ESD/EMI, microcontrollers, RF and wireless control, sensor ICs, smart card ICs, transistors, diodes, etc.
4. Texas Instruments (TI) (acquired National Semiconductor) Headquarters: USA Main business: Semiconductor design and manufacturing, analog circuit component manufacturing, innovative digital signal processing research and manufacturing, sensor control, educational products, and digital light sources.
5. STMicroelectronics (ST) Headquarters: Italy Main business: Analog chips and power conversion chips, set-top box chips, discrete devices, mobile camera modules, and automotive integrated circuits, etc.
6. Dialog Semiconductor Headquarters: Germany Applications: DA14580 selected by Xiaomi Mi Band. DA14580 is the world’s smallest, lowest power consumption, and highest integration Bluetooth smart SoC. Main business: Power management, audio, short-range wireless technology, touch, display, etc.
7. Nordic Semiconductor ASA Headquarters: USA Main business: Ultra-low power (ULP) RF specialty manufacturer.
8. Murata (makes Bluetooth modules) Headquarters: Japan Main business: Capacitors, inductors (coils), noise suppression components/EMI noise filter/electrostatic protection devices, resistors, thermistors, sensors, clock components, sound components, power supplies, micro-electromechanical products, RFID devices, matching devices, filters, circuit boards, negative ion generators/ozone generators, etc. Murata also makes Wi-Fi modules using Broadcom and TI’s Wi-Fi chips, ensuring high quality!
9. Actions Semiconductor Headquarters: Zhuhai Applications: Bluetooth speaker and Bluetooth sports earphone solutions. Main business: Supplier of portable multimedia SOCs. Integrated circuit chips include VR all-in-one machines, tablets, smart set-top boxes, Bluetooth speakers, Bluetooth sports earphones, Wi-Fi speakers, smart children’s toys, etc.
10. RDA Microelectronics Headquarters: Taiwan Applications: Bluetooth keyboard and mouse solutions. Main business: Leading domestic IC design manufacturer, dedicated to developing highly integrated circuits for wireless communications, providing customers with high-performance, low-cost RF/mixed-signal integrated circuit components, as well as complete Bluetooth/Bluetooth low energy system-on-chip solutions. Products mainly include mobile power amplifiers (PA), RF switches (T/R Switch), low-noise power amplifiers (LNA), digital television and satellite (DVB-S/S2) tuners, Wi-Fi RF transceivers, and Bluetooth system-on-chip. Currently, RDA’s products are widely used in various mobile phones, digital televisions and set-top boxes, Bluetooth input controls, audio peripheral devices, and wearable products.
11. Zhuhai Jieli Technology Co., Ltd. Headquarters: Zhuhai Applications: Bluetooth speaker series. Main business: Mainly engaged in the research and development of industrial control, health monitoring, IoT, smart home, and multimedia SOC chips.
12. Elan Microelectronics Headquarters: Taiwan Applications: Bluetooth keyboard and mouse solutions. Main business: A professional chip research and development and modular solution provider. One of its core technologies is capacitive touch technology.
