First, RFID technology analysis
1.1 Basic principles of RFID technology
In the 1980s, due to the maturity of large-scale integrated circuit technology, the size of the RFID system was greatly reduced and entered the stage of practical use, becoming a mature automatic identification technology. RFID technology uses radio frequency for contactless two-way communication to achieve identification purposes and exchange data. A typical RFID system consists of a tag, a reader, and an antenna.
1.2 RFID technology classification
RFID technology is mainly classified in the following four ways:
1.2.1 Classification of working frequencies
According to the different working frequencies, it can be divided into low frequency, high frequency, very high frequency and other systems. Systems operating at less than 30 MHz are generally referred to as low frequency systems. The low frequency system has the characteristics of low label cost, short reading distance, weak directionality of the reading antenna, and strong anti-interference. Mostly used in access control, e-card payment, etc. The most commonly used 13.56MHz RFID system is a low frequency system.
The high-frequency system generally refers to a system with a working frequency greater than 400 MHz, which has the characteristics of high cost of the tag and the reader, long reading distance, strong directivity of the reading antenna, and weak anti-interference. This frequency of RFID system, the reader still has a good recognition ability when the tag moves quickly, so it is widely used in train monitoring, highway toll and other systems. VHF systems generally refer to RFID systems with operating frequencies greater than 1 GHz. The outstanding feature is the long reading distance.
1.2.2 Label Reading and Writing Characteristics Classification
According to the different read and write characteristics of the tag, it can be divided into read/write (RW) tags, one
There are three types of write-once readout (WORM) tags and read-only (RO) tags. RW tags cost more, and it takes longer to read and write data than the other two tags. The RO tag has a unique identifier that cannot be modified to ensure security.
1.2.3 Tags have passive classification
RFID systems can be classified into active systems and passive systems depending on whether the tags carry power. Active RFID tags have a long read and write distance but are affected by power life. The life expectancy is relatively short. Passive RnD tags have low cost, long life and small size, but their read and write distances are short, usually only a few centimeters to tens of centimeters.
1.2.4 Classification of modulation methods
Depending on the modulation method, RFID systems can be divided into active and passive. In active RFID systems, the tag is typically an active tag. Actively send data to the reader using its own RF energy. In a passive RFID system. The tag must be excited by the reader's RF energy to feed back the data to the reader.
1.3 Advantages of RFID technology
RFID technology, barcode recognition technology, magnetic stripe recognition technology, fingerprint recognition technology and face recognition technology are all popular recognition technologies. The basic ideas of RFID technology, barcode recognition technology and magnetic stripe recognition technology are similar. They use the coded information to calibrate the physical objects to achieve the purpose of distinguishing and identifying the individuals to be calibrated. The application of biometrics such as fingerprint recognition and face recognition is relatively narrow, mainly by using the characteristics information of the organisms to achieve the biological The identification of the body.
Second, smart phone and related technology analysis
2.1 Smartphone operating system
An open operating system is one of the important features of smartphones. In the first half of 2008, the Linux-based open source open operating system jointly developed by Symbian, Linux and several mobile phone manufacturers has occupied 90% of the market. And the Internet giant Google and 34 companies including chip manufacturers, mobile phone manufacturers, operators and other companies jointly developed Android open source mobile operating system has also come out, showing that openness has become an irreversible development trend. Currently affecting mobile operating systems: 1, Symbian operating system; 2, Window Mobile operating system; 3, Linux operating system; 4, PalmOS operating system; 5, MacOSX operating system. Other smartphone operating systems include Google's Android smartphone operating system and BlackBerry's Blackberry RFID smartphone operating system. However, these operating systems are only used by their respective companies and lack the support of third-party software developers.
2.2 Combination of RFID technology and smart phones
RFID technology combined with smart phones, the most successful is NFC technology. The technology is jointly launched by manufacturers such as Philips, Nokia and Sony. NFC technology is a standards-based short-range wireless connection technology that enables simple and secure two-way interaction between multiple short-range electronic devices (communication distance is generally less than ten centimeters). NFC technology was originally a simple merger of RFID technology and Internet technology. With the development of these two technologies and the increasing demand of users for this technology, it has now evolved into a short-range wireless communication technology with corresponding standards.
NFC technology supports three different application modes: card mode, read-write mode, and NFC mode. Simply put, in the card mode state, the NFC mobile phone is equivalent to an RFID tag, the antenna communication protocol is based on the RFID platform based RFID middleware research ISO14443A, etc.; in the read/write mode state, the NFC mobile phone plays the role of the RFID reader Standard reading and writing of RFID tags with communication protocol such as ISO14443A; in the NFC mode state, two NFC mobile phones are equivalent to two devices connected by one channel, which can perform low-speed information transmission.
Third, RFID middleware
3.1 Introduction to RFID middleware
With the development of RFID technology, the research and application of RFID middleware is becoming more and more important. In RFID applications, permeability is the key to the entire application. Proper access to data, reliability of data reading, and efficient delivery of data to upper-level applications are issues that must be considered. Data transparency between traditional applications is solved through a middleware architecture, and various application service software are developed. RFID middleware acts as an intermediary between RFID hardware and applications. The application side uses a set of common application interface APIs provided by middleware to enable connection to RFID readers. In this way, even if the database software storing the RFID tag data, the upper application is added or replaced by other software, or the type of the read/write RFID reader increases, the application can be processed without modification, and the solution is solved. Maintenance complexity issues for many-to-many connections.
RFID middleware is a message-oriented middleware information that is transmitted from one program to another in the form of a message. Information can be transmitted asynchronously, so there is no need to wait for a response. Message-oriented middleware contains functions that not only convey information, but also include services such as interpreting data, security, and data broadcasting.
3.2 Smartphone platform RFID middleware
Non-mobile RFID middleware is relatively mature, there are many mature products on the market, such as Microsoft's BizTalkRFID middleware, Sybase's RFIDAnywhere series middleware, IBM's webSphere middleware and Tongfang's ezRFID middleware. However, RFID middleware in the mobile platform field that the smartphone platform belongs to has no mature products.
The RFID middleware of the smartphone platform is quite different from the RFID middleware in the large information system running on the PC. The RFID middleware on the smartphone platform should have the functions and features of the general middleware, namely data collection, filtering and packaging. This article uses event management to implement these general operations on data. Limited by resources, such as hardware computing power and power supply, it must be sufficiently streamlined to reduce the occupation of system resources and ensure high operational efficiency.
Venetian Blinds Spare Parts,Replacement Brackets For Venetian Blinds,Venetian Blind Spare Parts,Replacement Parts For Venetian Blinds
WUXI MIFUN INTERNATIONAL TRADE CO.,LTD , https://www.mifunblind.com