The use of RFID technology is governed by well-defined international standards, thanks to which elements of the system work together seamlessly, and it is guaranteed that even equipment from different manufacturers will communicate together. Use of RFID in the library is primarily based on the ISO 15693 and the ISO 18000-3 standard, which defines the operation of the RFID system in the HF frequency band at a frequency of 13.56 MHz. RFID technology is used for several frequency bands, each suitable for a different area of use.
The comparison is as follows:
|High frequency (HF) 13.56 MHz||ISO 18000-3|
- library science
|Ultra high frequency (UHF) 869 to 960 MHz||ISO 18000-6|| - logistics (track pallets in warehouses)|
- electronic toll gates
- parking cards
- medical use
The essence of everything is a framework consisting from a reader and a transponder. The transponder is placed on a medium or an object; the reader equipped with an antenna is either stationery or portable. The transponder consists of a memory chip, into which information is recorded, and a spiral antenna. But how can a transponder wirelessly transmit information if it’s not connected to any source of power? The antenna connected to the reader generates an electromagnetic field. If the RFID label with a transponder enters it, the spiral antenna is generating a current, which will charge the inbuilt condensator and it will activate the chip. It is important to know, that the reader alone does not create its own field, but only modifies (modulates) the field created by the reader. The reader detects these changes and transforms to digital data.
The fundamental part of the RFID system, when used in libraries, is the label – RFID tag (also called the smart sticker). For individual media types special kinds of labels where developed. Library labels have the shape of a flat rectangular sticker consisting of a plastic foil, on which a chip is placed with a spiral antenna and a paper cover with printable space. A similar label can be stuck on VHS tapes. For a CD and DVD medium, where due to the surface being plated and so the conditions for scanning are not as good as with books, several types of stickers can be used. From the simplest circular one to a large surface “complete” label with a bigger antenna for a perfect signal capture from as far as 45 cm, which is especially advantageous for detection in security gates.
The reader, in contrast to the transponder, is an active part of the RFID system. By transmitting the electromagnetic waves, it communicates with the transponder and either reads the data recorded in it or records new data. The reader used in the libraries works on a standard 13,56 MHz frequency in the VF wavelength. Data, which is recorded in the memory of the chip, is precisely stated in a so-called data model. It expressly states what information and in what format will be saved onto the chip. In our example, we strictly adhere to the so-called Danish data model. It includes, among others, the AFI byte (defined by the ISO 18000-3 norm), which contains information about the media borrowed / not borrowed and so forms the core of the RFID security feature. Data obtained by the RFID reader are transferred to a computer where they are processed by the appropriate software. Programs may also obtain information from the library information system by the contribution of standardized communication protocols. These protocols are mainly NCIP, SIP2, SLNP or Z3950.