Research On The Key Technology Of RFID Middleware

The fast development of RFID (Radio Frequency Identification) technique and the professional application of RFID in large scope challenged the original pattern of RFID application. This changing in pattern caused the emergence of RFID middleware. RFID middleware provides effective, reliable and Real-time tag event information for the application makes no-seam combine between enterprise information system and RFID hardware, brings Real-time RFID information to enterprise IT system. This could be an immense promote of enterprise IT system.Nowadays, although the RFID middleware has some applications in several domains, it is not grown up and it has many deficiencies. This article will support some solutions according to some of the key problems.On current moment, the levels of RFID application are irregular. Middleware is various in different application environment. Middleware is required to be simple in some simple application, take some Real-time system for instance, the complexity of middleware functions are no use and will affect the efficiency of the whole system. In some applications as supply chain management system, middleware should have abundant functions to meet the requirements. So, the middleware should be well constructed to suit all kinds of applications and environments. It's very necessary to do a research about high quality of extension and usage of the RFID middleware platform architecture. There is a 2-layer model architecture in this article, it can meet various application environment, every level is a independent system which provide different functions to customers, that give many more options to application system.Accompanied by abundant applications of RFID, the use of bar code and its identity devices would be continued. The combination of these devices and the RFID read-write devices makes a complex identity device network. The prospect of RFID read-write devices is the RFID read-write device network. Since current produced RFID devices lack a common interface standard, the management and modification of RFID devices need professional knowledge makes effective management and modification of RFID devices a big problem, the compositing of original identity devices and many kinds of RFID read-write devices as data format cannot be solved efficiently, The original identity device needs to be composite in devices and data, for example, on account of application history, bar code coding is very different from RFID tag coding, but RFID coding can composite bar code in theory, all these problems will cause negative affects to the development of RFID application. Most of current middleware do not think much of the management and compositing of physical identity devices, and it's the main defect of the current applications. In order to solve the problem of compositing, corresponding and management over every device, this article researches a reader network management model. Through the model, we can compositely use functions and data on many kinds of devices, provide a whole suite of management model, manage the read-write devices network intelligent, extend the low level read-write devices as the smoothing event handle, and the data compositing problem is solved and the same normal data is provided to upper layer.The information from identity device cannot be used directly by customers. First, these direct data is redundancy while the customer is only interested in some part of the information. Direct pass the data to customer cause waste of network and server resources, and bring chaos to application system. So the direct information needs to be filtered, this article will provide a filter arithmetic, which can filter data efficiently according to customer requirements. Second, the data is irregular for customer to use, so the data should be grouped, there's a grouping arithmetic in this article which will group the data according to the grouping rule. Third, the treated data should be subscribed and passed to subscribers asynchronously, based on the ALE specification, this article provides a data subscribe and send model.In this article, the "Shenzhen-Hong Kong Innovation Circle" major project "Food Safety System for export to Hong Kong" is as the background of research and application. "Food Safety System for export to Hong Kong" is a major research project in Guangdong Province, and using RFID technology for food supplied to Hong Kong by Shenzhen provides food safety management system, which includes monitoring food production, supply chain scheduling and sales management, is a typical RFID application environment.The article studies the protocol system of EPCglobal, and focuses on ALE (Application Level Event) specification associated with the RFID middleware. In the study of protocol and based on the combination of " Food Safety System for export to Hong Kong" project, designs a highly available and scalable RFID middleware platform architecture, and the system has a 2-layer structure: the reader network management layer and application level event layer. Reader network management layer is the management of a wide range of reader and easy to deal with the data. The reader network management can mask the differences of all kinds of reading equipment, and provide a unified data format; application level event layer is a major role in processing and sharing the event, processing event includes data filtering, aggregation and report, and can also be extended to data encryption and compression, the sharing event refers to the event of subscription and publish.This article designs an intelligent reader network management layer model and studies the model's basic features: compatible with a wide range of equipment, management equipment and coordination mechanisms. Intelligent reader network management, can coordinate the work of a number of readers to avoid the conflict, and adds basic data-processing, such as tag smoothing can reduce the volume of data and data format conversion to a compatible data format, and reorganize a number of data, and resolve the difficulty of managing all kinds of readers and the problem of data compatibility.The article of another important job is to design the application level layer model. In the model based on a new understanding of the usage of the field, and the field can use in the application of data encryption and compression; the article designs data filtering, aggregation and report of the mathematical model, which precisely define how the data to process in the math. The article also deeply studies the subscription of application level event, and designs a subscription mechanism to make that users can subscribe data which they interested in and custom data format.The configuration of this article: first, introduce of RFID and situations of middleware. Second, the 2-layer of middleware architecture according to the analysis, do a research on every layer particularly, and arithmetic to solve problems. In the last, the prototype of middleware implements tests on simple functions.