Bluetooth past and future

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Abstract This article introduces the origin, characteristics and technical advantages of Bluetooth technology. The application and future development of Bluetooth technology are analyzed, and the performance and advantages of Bluetooth solution based on BRF6100 chip are discussed.

Keywords Bluetooth, RF technology, CMOS, wireless Internet access

I. Introduction

In the future, not only will wireless Internet access become the main method of Internet access, but also various portable devices that people carry with them will also be connected into wireless networks, providing us with great convenience. There are many portable devices that we carry with us, including mobile phones, PDAs (personal digital assistants), notebook computers, digital cameras, portable game consoles, portable MP3 players, watches, and so on. Initially, people wired laptop computers to mobile phones and surfed the Internet wirelessly. Later, the PDA can be connected to a mobile phone to achieve wireless Internet access. Now mobile phones are the center, and various devices are connected into a wireless network to achieve wireless Internet access. In this way, as long as people put mobile phones in their pockets, laptops, PDAs, etc. can browse the Internet, and can also be used to send and receive e-mail; when receiving new e-mail, the watch can generate vibration while ringing a song to notify; by People on mobile phones can also automatically download music data to MP3 players and enjoy music through wireless headphones.

This type of network that wirelessly connects devices carried by individuals is called a personal area network (PAN). It uses a mobile phone as an information gateway to enable content exchange between various portable devices. This kind of PAN is no longer an idea. With the practicality of "Bluetooth" technology, PAN is becoming a reality.

1. The origin, characteristics and significance of Bluetooth

Bluetooth is a short-range wireless (2.4GHz) data communication technology proposed by Sweden Ericsson and other five companies to carry out standardization activities, and is now entering the practical stage. ---- In May 1998, Ericsson, IBM, Intel, Nokia, Toshiba and other five companies began standardization of short-range wireless communication technology. The goal is to achieve a maximum data transmission speed of 1Mb / s (effective transmission speed of 721kb / s) and a maximum transmission distance of 10 meters. Users can use the 2.4GHz ISM (industrial, scientific, medical) frequency band without permission. 79 channels with a bandwidth of 1MHz were set up, and the frequency spread of 1600 times per second and the spectrum spreading technology of the hobbing method were used to realize the transmission and reception of radio waves. This is the origin and characteristics of Bluetooth technology.

Devices that use Bluetooth technology for communication are divided into a "caller" that determines the frequency hobbing mode and its communication opponent "receiver". The calling party can communicate with 7 recipients at the same time. Therefore, a total of 8 devices including the calling party and the 7 recipients can be connected into a subnet named Piconet (Sawtooth Network). The recipients in Piconet can serve as the recipients of more than two Piconets at the same time. ---- In July 1999, Bluetooth announced the official specification BluetoothVersion1.0. Mobile phones and laptops that comply with this specification will be available in late 1999 or early 2000. The number of companies claiming to commercialize Bluetooth technology is increasing, and the number of member companies of the Bluetooth standardization group "BluetoothSIG (Special Interest Group)" has increased to more than 800.

In order to make Bluetooth popular, manufacturers using Bluetooth technology are concerned about two issues, one is to lower the price of transceiver equipment, and the other is the national regulations on the available frequency bandwidth. These two issues are the key to promoting Bluetooth.

Due to the low data transmission speed and transmission distance, the corresponding Bluetooth device can achieve low price and low power consumption. Each module was estimated to be US $ 20-30 when it was first introduced. With mass production and the use of high-frequency CMOS technology, its price can be reduced to US $ 5 each in 2001. Regarding frequency bandwidth regulations, governments of various countries are also actively relaxing restrictions on the use of the 2.4 GHz band.

Two technical characteristics

Bluetooth is an open, short-range wireless communication technology standard. It can be used to replace current multiple cable connection solutions in a short distance, penetrate barriers such as walls, and realize flexible, safe, low-cost, and small-function between various digital devices through a unified short-distance wireless link Consumption of voice and data communication.

The Bluetooth technical specification includes two parts: protocol and application specification. The entire Bluetooth protocol architecture can be divided into 4 layers, namely the core protocol layer, cable replacement protocol layer, telephone control protocol layer and other adopted protocol layers.

Bluetooth involves a series of software and hardware technologies, methods and theories, including wireless communication and network technology, software engineering, software reliability theory, protocol correctness verification, formal description and consistency and interconnection testing technology, embedded real-time operating system, Cross-platform development and graphical user interface technology, hardware and software interface technology, and highly integrated, low-power chip technology. 1. Radio frequency technology 2. Baseband 3. TDMA structure 4. Frequency hopping technology 5. Network characteristics 6. Global address 7. Protocol layering 8. Security.

The Bluetooth system is generally composed of four functional units: an antenna unit, a link control (firmware) unit, a link management (software) unit, and a Bluetooth software (protocol stack) unit. 1. Antenna unit 2. Link control (hardware) unit 3. Link management (software) unit 4. Software (protocol stack) unit.

The Bluetooth device relies on a dedicated Bluetooth microchip to enable the device to send radio signals within a short distance to find another Bluetooth device. Once found, they begin to communicate with each other. Currently, Bluetooth developers mainly seek solutions for their ASICs, including radio frequency and baseband components. There are various solutions to make the baseband ASIC circuit and the radio frequency ASIC circuit into a circuit module, and it is expected to enter the mass production stage soon. Most of the communication protocol of the Bluetooth system can be realized by software, and it can work by loading into the Flash RAM.

3. Application and development trends

1) Open up new uses for wireless connections: Now many watch manufacturers and game manufacturers have joined the Bluetooth SIG, indicating that they all need to use Bluetooth technology. Japan ’s Casio claims that many of their digital cameras, watches and other products will use Bluetooth technology in the future; show their skills in the third generation mobile communication: Japan will start the third generation mobile communication (WCDMA) service in March 2001 , NTT is studying the use of Bluetooth technology in mobile phones for this service. In May 1999, at the "99 Commodity Exhibition" held in Tokyo, manufacturers exhibited various models of W? CDMA mobile phones, many of which have separate receiving parts and handheld parts. People guess that this may be For wireless communication using Bluetooth technology.

Bluetooth will also be used in notebook computers: based on the information published by Ericsson, Intel, Dataquest, VLSI Technology, etc., we expect that by 2002, mobile phones using Bluetooth technology will reach 250 million, PCMCIA cards and modems using Bluetooth technology, etc. Peripheral equipment will reach 150 million units, and personal computers using Bluetooth technology will reach 25 million units; semiconductor manufacturers joining will help reduce prices: In addition to machine manufacturers, semiconductor manufacturers are also joining this field, which will help reduce transceiver modules price. The addition of large manufacturers will make the LSI used in mobile phones universal and single-chip; an important factor in accelerating the popularity of Bluetooth is the existing infrared communication technology IrDA (Infrared Data Alliance), Bluetooth will undoubtedly use IrDA software as much as possible Resources: Bluetooth SIG has published the Object Exchange Protocol (OBEX) using IrDA. The application software using OBEX does not care about the difference of machines and methods, so various objects can be exchanged. Now the industry is discussing the generalization of Bluetooth and IrDA upper layer protocols. For example, when the dialogue layer agreement between the two parties adopts OBEX formulated by IrDA, the same application software can be shared. In addition, IrCom's IrTranP protocol for transferring image files can also be used in the Bluetooth network layer and transport layer RFComm.

Casio Japan has performed a performance of using IrTran? P to transfer image files at the "CeBIT'99" exhibition held in Germany in March 1999. By combining TrTran? P and Bluetooth technology, people can use mobile phones and digital Transfer image files between cameras. The image in the digital camera is sent to the mobile phone through the public mobile phone network, and then displayed on the screen of the notebook computer through IrDA. The entire process took 40 seconds, mainly for data communication on the public mobile phone network. In this method, the lower layer uses Bluetooth and IrDA respectively, and the upper layer uses the existing IrDA protocol.

2) The Bluetooth development trend can be summarized as follows: First, small businesses attract capital, and investors look for promising small businesses, the purpose is to jointly find a breakthrough in technology and lower prices. Second, to solve the interoperability problem of Bluetooth, the current product conformance test is no problem, but can not communicate with each other. Bluetooth only makes sense when it becomes the esperanto of wireless communication. The current 2164 members seem thin. Third, for domestic companies, the key is to find the goal of developing applications, develop innovative application products in a targeted manner, and avoid conflicts with foreign companies. Fourth, considering the coexistence of Bluetooth and other technologies, Bluetooth is only an important technology in WPAN, which has limitations. The realization of WPAN network requires the combination of several technologies. Large companies often participate not only in one standard and one technology Development, such as Intel, participated in both Bluetooth, IEEE802, HOMERF, etc. Fifth, from a technical point of view, Bluetooth has developed towards a single chip, and has made some breakthroughs. Sixth, there has been a breakthrough in the solution of interference between Bluetooth and other standards, the power consumption of Bluetooth, and the volume of Bluetooth.

Our industry and people of insight should be pioneers in the development of Bluetooth and dare to innovate, because after years of sustained and steady economic growth, we have a considerable material and talent base and should make a difference in the development of Bluetooth .

Four Bluetooth solution based on BRF6100 chip

TI's BRF6100 is a highly integrated CMOS Bluetooth solution that forms a complete Bluetooth wireless communication unit. This design integrates Bluetooth baseband, radio frequency, memory and performance-enhancing processing chips, reducing costs and obtaining minimum board space.

BRF6100 is the first iteration of digital radio frequency, revolution in radio frequency technology that provides considerable advantages over analog radio frequency. These include reducing the changing magnetization coefficient, increasing testability, improved efficiency, low power consumption, easy integration with baseband and RF, and ultimately reducing costs.

The BRF6100 single-chip solution is as follows

Process: 0.13u CMOS, current consumption up to 25mA, integrated RF switch, support 3, 15.36, 16.8, 19.2, 19.44, 19.8, 26, 38.44 (MHz).
The complete transmission volume of all unit clocks (723.2K bps), the structured global asynchronous receiver obtains the rate of all PC global asynchronous receivers of the unit clock.

Sensitivity: -85 dBm, 1.7-3.6 supply voltage.

-40: The operating temperature of +85 degrees Celsius reaches seven active drivers, a channel of 25mA deep current.

The BRF6100 is suitable for low-cost, large-scale applications such as hand-held mobile devices. Its performance and space are the most decisive.

When taking advantage of the unique high-efficiency processing performance designed for RF digital processing, the advanced structure supports the TI0.13μCMOS process. The high degree of integration allows the formation factor of the solution to drop by 90mm2, which is used outside the Bluetooth chip through the integration of power management, PLL, loop filter, antenna switch, filter and other similar functions.

In addition, BRF6100 chip has other applications. For example: GPRS