What are the characteristics and comparison of Bluetooth, infrared and universal wireless communication technologies?

An article that our boss gave me. It might be useful to read it.

Introduction and comparison of several current hot short-range wireless technologies

Author: unknown

Time: 2008-0 102

At present, the widely used short-range wireless communication technologies include Bluetooth, WLAN 802. 1 1(Wi-Fi) and infrared data transmission (IrDA). At the same time, there are some potential short-range wireless technical standards, which are Zigbee, ultra-wideband, short-range communication (NFC), WiMedia, GPS, DECT, wireless 1394 and private wireless systems. They all have their own characteristics, or are based on the special requirements of transmission speed, distance and power consumption; Or focus on the expansion of functions; Or meet the special requirements of some single applications; Or establish the differentiation of competitive technology. But no technology can be perfect to meet all the needs.

Bluetooth technology

Bluetooth (in-situ) technology is a short-distance wireless connection technology that has emerged in recent years, which has aroused widespread concern in the industry. It is an open global wireless data and voice communication standard, based on low-cost short-distance wireless connection, which can provide cheap access services for fixed or mobile terminal equipment.

Bluetooth technology is an open global specification for wireless data and voice communication. Its essence is to establish a general short-distance wireless interface for the communication environment between fixed devices or mobile devices, and further combine communication technology with computer technology, so that various devices can communicate or operate with each other in a short distance without wires or cables. Its transmission frequency band is 2.4GHz ISM band widely used by the public all over the world, providing a transmission rate of 1 Mbps and a transmission distance of 10m. ..

Bluetooth technology was born in 1994. At that time, Ericsson decided to develop a low-power and low-cost wireless interface to establish communication between mobile phones and their accessories. This technology has also been supported by the industry giants in the PC industry. 1998, five companies including Ericsson, IBM, Intel, Nokia and Toshiba reached a Bluetooth technology agreement.

The standard version of Bluetooth protocol is 802. 15. 1, which was developed by Bluetooth Group (SIG). 802. The original standard of 1 5.1was realized on the basis of Bluetooth 1. 1, which has been built into many existing Bluetooth devices. The new version of 802. 15. 1a is basically equivalent to the Bluetooth 1.2 standard, with certain QoS characteristics, and completely maintains backward compatibility.

But the biggest obstacle of Bluetooth technology is that it is too expensive. Outstanding performance in the chip size and price is difficult to adjust, anti-interference ability is not strong, transmission distance is too short, information security issues and so on. This makes many users reluctant to spend a lot of money to buy such wireless devices. Therefore, experts in the industry believe that the market prospect of Bluetooth depends on the price of Bluetooth and whether the application based on Bluetooth can reach a certain scale.

Original location Wi-Fi technology

Wi-Fi (Wireless Fidelity) is also a wireless communication protocol, whose formal name is IEEE802. 1 1b, and it belongs to short-range wireless communication technology like Bluetooth. The highest rate of Wi-Fi is11MB/s. Although it is worse than Bluetooth technology in data security, it is slightly better in radio wave coverage, which can reach about100 m. ..

Wi-Fi is a wireless extension of Ethernet. Theoretically, as long as users are located in a certain area around an access point, they can access the Web at the highest speed of about11MB/s. But in fact, if multiple users access through a point at the same time, the bandwidth is shared by multiple users, and the connection speed of Wi-Fi is generally only a few hundred kb/s, and the signal is not blocked by the wall, but the effective transmission distance inside the building is smaller than outside.

The most potential applications of WLAN in the future will be mainly in SOHO, home wireless networks and buildings or places where it is inconvenient to install cables. At present, the users of this technology mainly come from public hotspots such as airports, hotels and shopping malls. Wi-Fi technology can integrate Wi-Fi with Web services based on XML or Java, which can greatly reduce the cost of enterprises. For example, enterprises choose to equip each floor or department with 802. 1 1b access points instead of connecting the whole building with cables. In this way, you can save a lot of money on laying cables.

The original IEEE802. 1 1 specification was put forward in 1997 and called 802.11b. Its main purpose is to provide WLAN access, which is also the main technical standard of WLAN at present. Its working frequency is also 2.4GHz, which is similar to many wireless devices that do not need frequency license, such as cordless phones and Bluetooth. With the emergence of new versions of Wi-Fi protocols such as 802. 1 1a, 802.1/g, the application of Wi-Fi will be more and more extensive. The faster 802. 1 1g uses the same orthogonal frequency division multiplexing modulation technology as 802.1/b. Working in 2.4GHz band, the speed is 54 MB/s. From the recent development trend of international consumer electronic products, 802. 1 1g is likely to be selected as the product standard by most manufacturers of wireless network products.

WindowsXP, a desktop operating system introduced by Microsoft, and WindowsCE, an embedded operating system, both contain support for Wi-Fi. Among them, WindowsCE also includes support for other wireless communication technologies such as Bluetooth, a competitor of Wi-Fi. With the cost of investing 802. 1 1b reduced, many manufacturers are involved in this field. Intel introduced a notebook chipset with integrated WLAN technology, which can realize wireless Internet access without an external wireless network card.

Original position IrDA technology

IrDA (Infrared Data Association) was founded in 1993. At first, wireless devices adopting the IrDA standard can only transmit data at the rate of 1 15.2 kb/s within the range of 1m, and it quickly developed to the rate of 4Mb/s and16 MB/s. ..

IrDA is a point-to-point communication technology using infrared rays, and it is the first technology to realize wireless personal area network (PAN). At present, its software and hardware technology is very mature, and it is widely used in small mobile devices, such as PDA and mobile phone. In fact, every PDA and many mobile phones, laptops, printers and other products that leave the factory today support IrDA.

The main advantage of IrDA is that it does not need to apply for the right to use frequency, so the cost of infrared communication is low. But also has the characteristics of small size, low power consumption, convenient connection and easy use required by mobile communication. In addition, the infrared emission angle is small and the transmission safety is high.

The disadvantage of IrDA is that it is line-of-sight transmission, and two communicating devices must be aligned and cannot be blocked by other objects, so this technology can only be used for the connection between two (not multiple) devices. Bluetooth, on the other hand, has no such restrictions and will not be blocked by walls. The current research direction of IrDA is how to solve the problem of line-of-sight transmission and improve the data transmission rate.

NFC technology

NFC(Near Field Communication) is a short-distance wireless communication technical standard similar to RFID (Contactless Radio Frequency Identification), which is mainly promoted by companies such as Philips, Nokia and Sony. Unlike RFID, NFC uses two-way identification and connection. It works in the frequency range of 13.56 MHz with a distance of 20 cm.

At first, NFC was only a combination of remote control identification and network technology, but now it has developed into a wireless connection technology. It can quickly and automatically establish a wireless network and provide "virtual connection" for cellular devices, Bluetooth devices and Wi-Fi devices, so that electronic devices can communicate in a short distance. The short-distance interaction of NFC greatly simplifies the whole authentication and identification process, and makes the mutual access between electronic devices more direct, safe and clear, without hearing all kinds of electronic noise.

NFC helps to solve the trouble of remembering multiple passwords by combining all identification applications and services on one device, and also ensures the security of data. Through NFC, a variety of devices will become possible, such as digital cameras, PDA, set-top boxes, computers, mobile phones and so on. Connect wirelessly and exchange data or services.

In addition, NFC can "accelerate" other types of wireless communication (such as Wi-Fi and Bluetooth) and realize faster and longer-distance data transmission. Each electronic device has its own dedicated application menu, and NFC can create a fast and secure connection without having to choose from many interface menus. Different from well-known short-range wireless communication standards such as Bluetooth, the range of NFC is further shortened, and there is no need for corresponding encryption equipment like Bluetooth.

Similarly, building a Wi-Fi home wireless network requires multiple computers, printers and other devices with wireless network cards. In addition, professionals with certain skills are required to be competent for this job. After NFC is put into the access point, only two of them need to be close to realize communication, which is much easier than configuring Wi-Fi connection.

NFC has three types of applications:

Home location device connection. In addition to WLAN, NFC can also simplify Bluetooth connection. For example, if a laptop user wants to surf the Internet at the airport, he only needs to be close to a Wi-Fi hotspot.

Real-time reservation at the original location. For example, stick a specific chip on the back of a poster or exhibition information, use a mobile phone or PDA with NFC protocol to get detailed information, or immediately use a credit card to buy tickets online. Moreover, these chips do not need independent energy sources.

Original location mobile commerce. Philips Mifare technology supports many large-scale transportation systems around the world, and provides customers with various services such as Visa cards in the banking industry. Sony's FeliCa contactless smart card technology products have a very high market share in China, Hongkong, Shenzhen, Singapore and Japan, and are mainly used in transportation and financial institutions.

In a word, this new technology is rewriting the game rules of wireless network connection, but the goal of NFC is not to completely replace other wireless technologies such as Bluetooth and Wi-Fi, but to complement each other in different occasions and fields. So the development trend of NFC, which is coming from behind now, is quite rapid!

Original position

zigbee technology

ZigBee is mainly used between various electronic devices with short distance and low data transmission rate. The name ZigBee comes from the communication mode that bees rely on for survival and development. Bees share information such as the location, distance and direction of newly discovered food sources through zigzag dance.

ZigBee Alliance was established in August, 20001year. In the second half of 2002, Invisible, Mitsubishi, Motorola and Philips Semiconductors announced that they had joined the ZigBee Alliance to develop the next generation wireless communication standard named ZigBee. So far, the alliance has about 27 member enterprises. All these companies have participated in the IEEE 802. 15.4 working group, which is responsible for formulating ZigBee physical and media control layer technical standards.

ZigBee Alliance is responsible for formulating protocols above the network layer. At present, the formulation of standards has been completed. ZigBee protocol is simpler and more practical than Bluetooth, high-speed personal area network or 802. 1 1x wireless local area network.

Zigbee can be said to be the brothers and sisters of Bluetooth. Using 2.4 GHz frequency band and frequency hopping technology. Compared with Bluetooth, ZigBee is simpler, slower, and has lower power consumption and cost. Its basic rate is 250kb/s, and when it is reduced to 28kb/s, the transmission range can be extended to 134m, and higher reliability can be obtained. In addition, it can be networked with 254 nodes. It can support games, consumer electronics, instruments and home automation applications better than Bluetooth. People expect to expand the application of ZigBee in industrial monitoring, sensor networks, home monitoring, security systems and toys.

The technical features of ZigBee in its original position mainly include the following parts:

The original position data transmission rate is low. Only 10KB/s ~ 250KB/s, focusing on low transmission applications.

Low power consumption in the original position. In low-power standby mode, two ordinary No.5 dry batteries can be used for more than 6 months. This is also a unique advantage that ZigBee supporters have always been proud of.

The original site selection cost is low. Because of the low data transmission rate and simple protocol of ZigBee, the cost is greatly reduced. Motorola and Philips, which actively invested in the development of ZigBee, officially launched their chips in 2003. Philips estimates that the cost of chips used in terminal products such as mainframes is more competitive than Bluetooth.

The original location has a large network capacity. Each ZigBee network can support up to 255 devices, which means that each ZigBee device can be connected with another 254 devices.

The effective range of the original position is small. The effective coverage range is between 10 ~ 75m, depending on the actual transmission power and various application modes, which can basically cover ordinary home or office environment.

The working frequency band in the original position is flexible. The frequency bands used are 2.4GHz, 868MHz (Europe) and 9 15MHz (USA), all of which are unlicensed.

According to the current idea of ZigBee Alliance, the target market of ZigBee mainly includes PC peripherals (mouse, keyboard and game joystick), consumer electronic devices (remote control devices on TV, VCR, CD, VCD and DVD) and intelligent control in the home (lighting, gas metering control and alarm, etc.). ), toys (electronic pets), medical care (monitors and sensors) and industrial control.

In-situ UWB technology

UWB (Ultra Wideband) is a wireless carrier communication technology, which uses nanosecond non-sinusoidal narrow pulse to transmit data instead of sinusoidal carrier, so it occupies a wide frequency spectrum.

Ultra-wideband can transmit signals in a wide bandwidth. The FCC of the United States stipulates that UWB occupies more than 500MHz bandwidth in the 3. 1 ~ 10.6 GHz frequency band. UWB has developed rapidly in recent years because it can realize high-speed data transmission with low power consumption and low complexity transmitter/receiver. It uses low-power pulses to transmit data in a very wide spectrum range, which will not cause great interference to the conventional narrow-band wireless communication system and can make full use of spectrum resources. High-speed data transceiver based on UWB technology has a wide range of applications.

The original positioning UWB technology has the advantages of low system complexity, low power spectral density of transmitted signals, insensitivity to channel fading, low interception ability and high positioning accuracy, which is especially suitable for high-speed wireless access in indoor and other dense multipath places, and is very suitable for establishing an efficient wireless local area network or wireless personal area network (WPAN).

UWB is mainly used in radar and image system, with small operating range and high resolution, and can penetrate walls, ground and body. In addition, this new technology is suitable for local area networks or personal local area networks with high speed requirements (greater than 100 Mb/s).

The most unique application of UWB will be wireless personal area network (pan) for video consumption and entertainment. The existing wireless communication methods, 802. 1 1b and Bluetooth, are too slow to transmit video data. 54 Mb/s 802. 1 1a standard can handle video data, but it is expensive. However, UWB may support the data transmission rate as high as 1 10 Mb/s in the range of 10 m, and it can complete video data processing quickly, simply and economically without compressing data.

The location of the original text has certain compatibility and the advantages of high speed, low cost and low power consumption, which makes UWB more suitable for the needs of the home wireless consumer market: UWB is especially suitable for transmitting a large amount of multimedia data at short distance and high speed, and can penetrate obstacles, which makes many commercial companies regard it as a promising wireless communication technology and apply it to wireless transmission of video signals from set-top boxes to digital TVs and other home occasions. Of course, the future of UWB depends on the technical development, cost, user habits and market maturity of various wireless schemes.

Original position summary

No matter what communication mode you see or are using, although each wireless technology will encounter its own special tasks, and people use different technologies in different places, they are likely to work together. For enterprises, bypassing major wireless communication operators can save considerable costs. In the long run, enterprises should pay close attention to the development of various wireless communication technologies and choose a standard that best suits their needs.