Subversion of the past, the personal area network to find a breakthrough

In recent years, the development of science and technology has caused people to carry more and more electronic information devices. Laptops, mobile phones, PDAs, etc. are no longer just necessary tools for business people. They are used by more ordinary people. The problem of information exchange between devices has become increasingly apparent.

The rise of the Internet of Things opened a big window for it. Various kinds of short-range wireless communication technologies are developing vigorously, and a brand-new concept has been derived—Personal Area Network (PAN). From the simple networking of the past to the establishment of the current personal area network, it is a new chapter in the writing of science and technology to human life.

The core idea of ​​the so-called personal area network is to use radio or infrared instead of the traditional wired cable to realize the intelligent interconnection of personal information terminals and form a personalized information network. Currently, it is mainly used in home and small office applications. Its main applications include: Voice communication gateways, data communication gateways, information appliance interconnections, and information exchanges.

Current situation at home and abroad: The four major technologies are still competing with each other to review the research status of personal local area networks at home and abroad. There are four main technologies for implementation: Bluetooth, IrDA, 802.11 and Home RF.

Bluetooth has fast frequency hopping, low power consumption, strong flexibility, easy to penetrate obstacles, and achieves all-round data transmission. Therefore, it has more advantages in mobile device interconnection, and is especially suitable for a wide range of activities and requirements. The devices are rapidly interconnected, such as laptops, digital cordless phones, personal digital assistants (PDAs), and mobile phones.

IrDA is a technology that uses infrared to perform point-to-point communication. It has the characteristics of small size and low power required for mobile communication devices. The transmission rate is at the head of the four and can reach 16 Mb/s. Due to the point-to-point connection, less interference is encountered. IrDA technology is the first choice for devices that require high transmission rates, low usage times, small movement range, and low prices, such as printers, scanners, and digital cameras.

However, it should be noted that IrDA technology is a line-of-sight technology with no obstacles in the middle. Second, the infrared component of the IrDA device, the core component of the IrDA device, is not a very durable device for scanners and digital cameras that are not frequently used. Although the equipment is more than adequate, it can quickly become overwhelmed if Internet access is used on mobile phones equipped with IrDA ports.

IEEE802.11 has a long transmission distance and high speed, which is suitable for the medium-distance wireless network in the company. IEEE 802.11 works in the physical layer and MAC layer of the open system interconnection reference model. Its MAC layer uses a carrier to monitor multiple access/collision avoidance protocols. At the physical layer, IEEE 802.11 defines three different physical media: infrared, Frequency Hopping Spread Spectrum (FH) and Direct Spread (DS). IEEE802.11 supports data rates of 1-11 Mb/s, but due to its high cost and high power consumption, it is rarely used in personal area network implementations.

Home RF is designed for home users because the radius of activity of this environment is greater than the range of activity defined by Bluetooth technology, and less than the radius of IEEE802.11.

Looking to the future: Bluetooth is expected to break out?

Since the Internet has become the de facto interconnect standard, the wireless network must use the same TCP/IP protocol as the current Internet. Bluetooth's BNEP (Bluetooth Network Encapsulation Protocol) protocol provides seamless switching between Bluetooth data packets and Ethernet data packets. Therefore, using Bluetooth to replace wireless networks with wired networks becomes the preferred solution for personal area networks.

In addition, Bluetooth technology has greatly promoted the development of personal area networks. Bluetooth technology is a short-range wireless communication technology that supports point-to-point, point-to-multipoint voice and data services. Its original intention is to use a miniaturized, low-cost and low-power wireless communication technology to form a kind of The network around the individual makes it possible for all information-based mobile or fixed devices within the coverage area to achieve “seamless” resource sharing. The substance of the network is to establish a common open standard for radio air interfaces and their control software. The further integration of communications and computers enables devices manufactured by different manufacturers to have interoperable and interoperable performance at close range without the interconnection of wires.