RFID Middleware Design and Architecture

Radio Frequency Identification (RFID) is a form of Automatic Identification and Data Capture (AIDC) technique (Ishikawa et al., 2003). RFID is recently being used in a wide range of areas such as Supply Chain Management (SCM), health care, traffic monitoring, retail, and access control (Polniak, 2007). The ability to store large amounts of data and identify items which are not in the line of sight has given RFID technology an edge over other automatic identification approaches such as the barcode based systems (Ishikawa et al., 2003) and optical character recognition systems (OCR) (Phoenix Software International, 2006). As an example, RFID technology integration in SCM systems has resulted in the reduced losses and improved visibility in various stages of supply chaining (Sheng et al., 2008), reduced numbers of data entry errors, efficient inventory management, and lower human labor costs in distribution centers (Tutorial-Reports, 2007). A binary code comprising a field of bars and gaps arranged in parallel configuration is used by the barcode based identification systems. The analysis of the reflected beam on the bar gaps, allows the numerical and alphanumerical interpretation of the barcode sequence made up of narrow and wide bars. The interpreted value obtained specifies a unique code that is used for object identification. The disadvantage of the barcode system is that the barcode needs to be aligned in order to be read by the laser scanner (Ishikawa et al., 2003). The OCR based systems consist of optical machine readers used to recognize alphanumeric codes which are placed on the objects to be uniquely identified. The drawbacks of this system consist of the cost of operation, and the complexity of the OCR readers (Phoenix Software International, 2006). The RFID systems basically consist of three elements: a tag/transponder, a reader and a middleware deployed at a host computer. The RFID tag is a data carrier part of the RFID system which is placed on the objects to be uniquely identified. The RFID reader is a device that transmits and receives data through radio waves using the connected antennas. Its functions include powering the tag, and reading/writing data to the tag. As shown Fig. 1, the signals sent by the reader‘s antennas form an interrogation zone made up of an electromagnetic field. When a tag enters this zone, it gets activated to exchange data with the reader (Al-Mousawi, 2004). Later, the identification data read by the RFID reader is processed by the software system, known as the RFID middleware. The RFID middleware manages readers, as well as filters and formats the RFID raw tag data so that they can be