Table of Contents
The Internet of things is to connect any object with the Internet for information exchange and communication through information sensing equipment such as radio frequency identification (RFID), infrared sensor, global positioning system and laser scanner according to the agreed protocol. A network to realize intelligent identification, positioning, tracking, monitoring and management. The Internet of things is the “Internet of things”. This has two meanings: first, the core and foundation of the Internet of things is still the Internet, which is an extended and expanded network based on the Internet; Second, its client extends and extends to any goods and goods for information exchange and communication.
EPC (electronic product code) system is based on computer Internet and radio frequency identification (RFID). Using the coding technology of the global unified identification system to give each entity object a unique code, a physical Internet for real-time sharing of global item information is constructed.
The emergence of EPC system will provide an unprecedented and almost perfect solution for supply chain management. The Internet of things based on EPE software and hardware technology can realize the connection and “communication” of everything in the world at any time and anywhere, which will fundamentally change the whole process of product production, storage, procurement, transportation, sales and consumption. It is the extension and expansion of the application of bar code technology.
If RFID tags are added to each product, the reader will continue to receive a series of product electronic codes in the process of product production, transportation and sales. The most important and difficult link in the whole process is how to transmit and manage these data. In order to manage these huge data streams, a layered and modular middleware (RFID Middleware) is introduced in the automatic identification product technology.
RFID middleware is an intermediate program to realize data transmission, filtering and data format conversion between RFID hardware equipment and application system. Various data information read by RFID reader and writer are extracted, decrypted, filtered and format converted by middleware to guide the enterprise’s management information system, and reflected on the program interface through the application system for operators to browse, select, modify query. Middleware technology also reduces the difficulty of application development, so that developers do not need to directly face the underlying architecture, but call through middleware.
1.2 characteristics of RFID Middleware
Rbtd middleware is a message oriented software middleware. Information is transmitted from one program module to another or more program modules in the form of messages. Messages can be sent asynchronously, so the sender doesn’t have to wait for a response. Based on the development of the original enterprise application middleware and combined with its own application characteristics, RFID middleware further expands and deepens the application of enterprise application middleware in enterprises. Its main features are:
Independence: RFID middleware is independent and between RFID readers and back-end applications. It does not depend on a certain RFID system and application system, and can be connected with multiple RFID readers and back-end applications to reduce the complexity of architecture and its maintenance.
Data flow is the most important part of RFID middleware. Its main task is to convert the entity object format into virtual objects in the information environment. Therefore, data processing is the most important function of RFID. RFID middleware has the characteristics of data collection, filtering, integration and transmission, so as to transmit the correct object information to the application system at the back end of the enterprise.
Processing flow: RFID middleware is a message in question. Its function is to provide sequential message flow and has the ability of data flow design and management. Data transmission path, data routing and data distribution rules need to be maintained in the system. At the same time, manage the security of data in data transmission, including data consistency, and ensure that the data received by the receiver is consistent with the sender. At the same time, we should also ensure the security of data transmission.
2. Key technologies of RFID Middleware
RFID middleware is between reader and enterprise application in the Internet of things, which is equivalent to the neural system of the network. The middleware system adopts a distributed structure to organize and manage the data flow hierarchically. It has the functions of data collection, filtering, integration and transmission. Therefore, it can transmit useful information to the enterprise back-end application system or other middleware systems.
Each middleware system is distributed on each level node of the supply chain, such as production workshop, warehouse, distribution center, retail store, and even on the means of transportation. The middleware system at each level will collect, store and process information, and communicate with other middleware systems. For example, a middleware system running in a store may notify the distribution center that other products are needed, while the middleware system in the distribution center notifies that a batch of goods have been shipped at a specific time.
Due to reader writer exceptions or mutual interference between tags, sometimes the collected EPC data may be incomplete or wrong, or even missing reading. Therefore, the middleware should smooth the EPC data stream read by the reader, which can remove its incomplete and wrong data and minimize the possibility of missing reading.
The reader / writer can identify all tags within the read range, but does not process the data. The data read by RFID devices is not necessarily used only by one application. It may be used by multiple applications (including various application systems within the enterprise and even the application systems of enterprise business partners). Each application system may also need many different sets of data. Therefore, the middleware needs to process the data accordingly (such as redundant data filtering and data aggregation). There are many problems to be solved in the research of RFID middleware. Here we mainly discuss three key problems: data filtering, data aggregation and information transmission.
2.1 data filtering
The middleware receives a large amount of EPC data from the reader / writer, which contains a large amount of redundant information and some misread information. Therefore, it is necessary to filter the data, eliminate redundant data, and filter out “useless” information in order to transmit it to the application or superior middleware for “useful” information.
Redundant data includes:
The same reader / writer will report the same data repeatedly in a short time. For example, in warehouse management, fixed goods are repeatedly reported, and the same items are repeatedly detected in the process of purchase and shipment.
Multiple adjacent readers and writers report the same data. There is a certain miss detection rate in the reader / writer, which is related to the placement position of the reader antenna, the distance between the object and the reader, and the texture of the object. Usually, in order to ensure the reading rate, multiple readers may be placed adjacent to each other in the same place. In this way, multiple readers and writers may report the monitored items, which may be repeated. In addition to the above problems, in many cases, users may also want to get the information of some specific goods, emerging goods, disappeared goods, or goods read by readers and writers in some places. When using data, users want to minimize redundancy and get accurate data close to the requirements as much as possible, which depends on middleware.
The solution to redundant information is to set up various filters for processing. There are many kinds of filters available. There are four typical filters: product filter, time filter, EPC code filter and smoothing filter. The product filter only sends product information related to a certain product or manufacturer, that is, the filter only sends EPC data in a certain range or mode. Time filters can filter events based on time records. For example, a time filter may only send events in the last 10 minutes. Only a certain EPC code can be sent. The smoothing filter is responsible for dealing with those errors, including missing reads and reading errors. According to the actual needs, the filter can be spliced one by one like a puzzle to obtain the desired events. For example, a smoothing filter can be combined with a product filter to separate events of interest to anti-theft applications.
2.2 data aggregation
The original RFID data stream received from the reader is simple and scattered single information. In order to provide meaningful information to applications or other RFID middleware, RFID data needs to be aggregated. Complex event processing CEP technology can be used to process RFID data to obtain meaningful event information. Complex event processing is an emerging technical field, It is used to deal with a large number of simple events and sort out valuable events. It can help people analyze such simple events, infer complex events, transform simple events into valuable events, and obtain operable information.
2.3 information transmission
The filtered and aggregated RFID data needs to be transmitted to those entities interested in it, such as enterprise applications, EPC information service systems or other RFID middleware. Here, the message service mechanism is used to transmit RFID information. RFID middleware is a message oriented middleware (MOM), which transmits information from one program to another or more programs in the form of messages, Information can be transmitted asynchronously, so the sender does not have to wait for a response. The function of message oriented middleware is not only to transmit information, but also to explain data, security, data broadcasting, error recovery, locate network resources, find out the path that meets the cost, prioritize messages and requirements, and extend debugging tools.
The message transmission structure between RFID middleware and enterprise application or other middleware is realized through Java Message Service (JMS) in J2EE platform. The publish subscribe mode of JMS is adopted here. RFID middleware publishes a message to a topic. Enterprise applications and one or more other middleware can order the topic information. The message is in the format of physical markup language PML, the special language of the Internet of things. In this way, when the database software that stores RFID tag information in real time or increases the types of RFID readers and writers occur, the application side can process the data without modification, eliminating the problem of maintenance complexity of many to many connections.
This paper briefly introduces the Internet of things and the application of RFID in the Internet of things, and expounds the three characteristics of RFID and the solutions of three key technologies. As the neural system of the Internet of things, RFID middleware realizes the connection between reader and writer and enterprise application end, eliminating the problem of maintenance complexity of many to many connection. Reduce the cost of enterprise integration. However, RFID middleware is a complex and important system, and its further popularization and application still needs to be improved step by step.
Source: China RFID Middleware Solutions – Actility Technologies Company Limited (www.tractility.com)
Actility provides powerful security solutions for retail store management to prevent asset and property losses, improve transaction security, and provide intelligent analysis. We produce AM/EM/RFID systems, EAS tags, EAS soft tags, EAS safer, lanyards, detachers and all kinds EAS accessories products. Infrared people counter and camera people counter is available. If you want to have more information about the article or you want to share your opinion with us, contact us at [email protected]