Tech?Update: Radio-frequency Identification (RFID)

RFID (Radio-frequency Identification) has been one of the most discussed technologies, and there are many controversies regarding it. Back in the sixties RFID began to develop as a discrete technology and has spread out to many fields of application ever since. While its advocates revel in utopian application scenarios, its adversaries point towards problems of data security and privacy. We will have a quick look at how RFID works and where it is applied.

Development, History and Fields of Application

Usually the tags or transponders used by the British Royal Air Force in its airplanes for friend-foe recognition during World War II are cited as the beginning point of RFID technology. These were heavy devices the size of suitcases. Since then, they have shrunk into todays tiny and super thin RFID transponders. Their presence is so inconspicuous that it is often not noticed or forgotten by the users. RFID was originally used for securing goods (theft prevention) and animal identification in farming. Its breakthrough came in the eighties when the US and some other countries drove RFID for the use in traffic toll systems. Since then it spread out to a great number of contemporary applications. Currently the major fields of RFID application are logistics, supply chain management, warehousing, and retail where it is used alongside barcode technology. Other applications include automotive and animal identification, e-ticketing, time registration, proof of authenticity (bank notes, pharmaceuticals etc.), and access control.

Components: Active and Passive Transponders and a Reader

Technically RFID is very complex in its many details. It does not help that its components are only partially standardized. However, standardization is progressing in RFID technology and will lead to greater compatibility and unification of RFID applications. Roughly, RFID requires three components: a RFID transponder, a reader or reader-writer, and a radio frequency.

Transponders are the core of every RFID system. The term is composed of the words transmitter and responder. Depending on the RFID system a transponder consists of a microchip, an antennae, a mounting, perhaps a chassis and a power source. Form, size and equipment of a transponder is defined by the field of operation and the frequencies used. The microchip contains the data which it receives via the antennae and sends upon request.

If a transponder has its own power source, such as a battery, it is an active transponder. This does not mean that it actively sends out data. An active transponder uses its battery to feed energy to the microchip when a reader requires the transmission of data. In this way the transponder needs less field energy which enables greater ranges. When no data transmission is requested the chip is in stand-by mode und does not use any power.

A passive transponder does not have a power source of its own. This makes it lighter and lowers its production costs but shortens its range and makes it more prone to interferences.

Sometimes range pole transmitters are used. They do not react to requests but transmit their data in certain intervals, which requires them to be provided with a power source.

The corresponding reader, or writer (in case of rewritable transponders) is equipped with software for processing the data sent by the transponder. Form and size of the reader/writer again depends on the RFID system used: From a hand-held unit to a fixed large device everything is possible.

Mode of Operation and Data Transmission

In order to read the data sent by the transponder, the reader creates an electromagnetic field which contains the orders for the transmission of certain data (serial numbers, product codes etc.). The antennae receives the data and passes it on to the microchip. During data transmission the transponder does not create its own electromagnetic field but slightly changes the field generated by the reader. Depending on the frequency and the distance between transponder and reader this reading process can be very fast. Data transmission is either via full duplex or half duplex communication.

Certain materials may cause interferences which distort or impede the transmission. Depending on the RFID system water, metals or other very dense materials may cause such interferences.

Frequencies, Range and Capacity

Another important RFID component is the frequency used for data transmission as it defines the possible distances between reader and transponder. The frequency bands used are:

LF – Low Frequency:

frequency band 30 – 300 kHz
max. range 0.5 m (passive) – 2 m
frequencies allowed 9 kHz – 135 kHz
typical fields of application: animal identification, logistics, distribution, access control, immobilizer systems

HF/RF – High Frequency:

frequency band 3 – 30 MHz
max. range 0.5 m (passive) – 2 m
frequencies allowed 6.78 MHz, 13.56 MHz (smart cards, 1 m), 40.680 MHz
typical fields of application: smart cards, logistics, packets, production, automation

UHF – Ultra High Frequency:

frequency band: 0.3 – 3 GHz
max. range 3 - 6 m (passive) – 100 m
frequencies allowed 433.920 MHz 8 (100 m), 869 MHz (Europe, 2 m), 902 – 928 MHz (USA, 2 m), 2.45 GHz (2 m)
typical fields of application: EAN codes, EPC codes, automation, production, logistics, automotive

SHF – Super High Frequency:

frequency band > 3 GHz
max. range ca. 10 m (active, requires battery)
frequencies allowed 5.8 GHz, 24.125 GHz
typical fields of application: Due to the very high read rate used in applications for quickly passing vehicles (toll systems, car parks, freight cars in train stations, trucks in gateways etc.).

Prospects: RFID vs. Barcode, Future Fields of Application

RFID shares fields of application such as logistics with barcode and 2D code technologies. Experts expect this to continue. RFID will spread out to applications which require low interference and efficient processes. Unlike barcodes RFID transponder chips are writable or rewritable. For example, they can be used to transmit parameters for the correct alignment of devices and machines and their equipment. A scenario for future RFID application is cashless shopping: People walk into a shop, take the goods from the shelves, put them into their shopping basket and simply walk out again. The prices of the goods are automatically computed and deduced from the bank account. At the same time intelligent shelves order the goods to be refilled. The refrigerator at home, too, could order goods taken out or warn its owner of expired foodstuffs. RFID implants into human skin are already reality – in this case one does not even have to carry a transponder along.

While some people are enthusiastic about such possibilities, others are worried by the implications of the "transparent user" and the possibilities of using RFID for total control and surveillance. Data privacy issues include questions such as who can save what data where and how long, and the issue of "skimming" data in passing without consent or even knowledge of the user, e.g. in case of ID cards. Such controversies regarding the fields of RFID application are likely to accompany the further development of this technology for awhile.

RFID at SEH

Our TPR-10 ThinPrint Reader enables contactless user authentication at printers via RFID. This system requires the installation of ThinPrint Personal Printing, a solution by Cortado, and together these solutions provide for secure printing: Users send their print job to their printer of their choice and then release the print job at the printer with the help of a smart card. In this way nobody else can pick up the print job. All common smart cards can be used for this solution, including smart cards already in use in a company or organization. Also, our RFID labels can be used to simply "upgrade" other smart cards by adding MiFare technology so they can be used with ThinPrint Personal Printing. As a result, it is not necessary to acquire another set of smart cards for Personal Printing.