Survivability Enhancing Techniques for RFID Systems

Introduction

Radio Frequency Identification (RFID) is a wireless technology for automatic item identification and data capture. It uses radio signals to identify a product, an animal or a person. Given its technical and economic advantages, RFID has been applied to various fields. Many retailers and wholesalers use RFID systems to manage product shipments and inventory tracking. RFID has also been used in critical information systems in military, healthcare, and crisis management. For instance, the US Food and Drug Administration proposed attaching RFID tags to prescription drug bottles as a pedigree. The Department of Defense is moving towards RFID-based logistic control.

The structure of a typical RFID system is shown in Figure 1 and such a system includes the following two major subsystems (Karygiannis, Eydt, Bunn, & Phillips, 2007; Zuo, Pimple, & Lande, 2009):

Figure 1.

Architecture of an enterprise RFID system

• 1)

  A Radio Frequency (RF) subsystem: It consists of components which perform tag identification and wireless communications and transactions between RFID readers and tags. A tag is physically attached to an item with a unique identification. A reader is a device that can recognize the presence of RFID tags and read the information supplied by them. It can be a PDA, a mobile phone or any kind of devices capable of communicating with an RFID tag. To obtain data from a tag, a reader first queries the tag and then forwards the received identity information to a backend server, which maintains a database of tag entries (see below). After being authorized, the reader can obtain more detailed information about the tag and the tagged item.

• 2)

  An Enterprise subsystem: It consists of two components: a backend database and an RFID server.

  • a)

    Backend database: The backend database contains an entry for every valid tag in the system. Each entry corresponding to a tag contains at least the following information: the tag identification number, the secret key shared between the database and the tag, and optional item descriptions of the tagged item. An RFID reader and the backend server communicate through a secure channel;

  • b)

    RFID Server: It consists of systems and applications which communicate with the RFID readers and process data acquired from the RF subsystem. Three components constitute an RFID server:

    • i)

      Reader interface: an interface to communicate with the readers.

    • ii)

      Middleware: An intermediate layer between the lower level RF subsystem and the higher level database and a set of user applications. The main purpose of the middleware is to pre-process the data collected from the RF subsystem and provide cleaned data to the tag database to be used by the higher level business applications. The raw data collected from the RF subsystem must be pre-processed to remove redundancy and/or transformed to appropriate formats before they can be used. Middleware also contains security mechanisms to ensure data confidentiality and integrity.

    • iii)

      Tag Database: Cleaned tag data is stored in this database to be used by the high level applications. This database may also contain high level events retrieved from the lower level tag data.