Add a User Interface to UHF RFID Tags

By József Bánlaki, Miklós Hoffmann and Tibor Juhász

Making a simple amendment to the EPC Gen 2 standard will allay privacy concerns, give consumers the ability to control tag behavior and enable new applications.


Having examined the obstacles to the spread of radio frequency identification technology, we have found that the most significant was the low level of social acceptance, due to consumers’ fear of privacy invasion. People worry—in some cases, with good reason—that this technology might detect their whereabouts and movements, as well as observe their habits.

Therefore, we propose that EPCglobal‘s Class 1 Gen 2 standard be amended to require a user interface that allows consumers to detect tags attached to the merchandise they purchase, and to control those tags’ behavior. Our proposal opens a new dimension for the use of ultrahigh-frequency (UHF) and Near Field Communication (NFC) tags, which will introduce the concept of “broadcast” that is, so far, unknown with passive UHF RFID technology.

Left to right: József Bánlaki, Miklós Hoffmann and Tibor Juhász

In the corporate world, the advantages of deploying UHF RFID technology are now undisputed. By increasing the effectiveness and reliability of business processes, RFID offers enterprises a quick return on investment (ROI), even though it may require that a company deploy relatively expensive infrastructure in order to use the tags. Consumers, on the other hand, are unlikely to achieve such an ROI. As such, the technology’s spread is typically confined to the business sphere.

As long as RFID applications remain within that sphere, there is little risk that the technology will generate the abovementioned privacy fears, of course, since in such cases, consumers do not encounter the tags. In a number of RFID applications, however, the tags’ lifecycle extends beyond supply chain businesses applications, and the tags are linked to the products consumers purchase—often intentionally, in order to obtain additional information.

A number of surveys and studies prove the appropriateness of consumers’ fears, particularly in countries where the use of RFID technology is widespread. Consumers are not confident that any data collected will be strictly impersonal. The business sector’s hunger for information is, in many cases, specifically aimed at detecting complex relationships—that is, assigning the data generated by various technologies (for example, credit cards, mobile phones, the Internet and RFID) to shoppers’ habits. Such knowledge can lead to a significant advantage in a competitive market, so it is not at all surprising that this hunger for information is determined by profit interest. This is an important point, because profit motive should be considered as a natural drive within the conditions of the market economy. But this does not mean that profit motive should not be limited by society’s interests.

One response to such consumer fears would be to oblige retailers to remove the RFID tags the moment that shoppers purchase tagged items. However, this would not only impose extra work on retailers, but also irrevocably deprive a purchaser of the opportunity to benefit from the tag’s ability to provide information regarding a product’s origin or usability. For instance, a washing machine equipped with a UHF RFID reader could use the instructions stored in clothes’ transponders to select the proper washing program.

Therefore, we must find a solution that protects a consumer’s privacy while offering him or her the advantages that the technology has to offer. In addition to the legal environment and the development of social awareness, the world’s leading professional organizations recommend, first and foremost, that the technology offer a solution to this problem (see Commission Recommendation of 12 May 2009 and Document 9303).

Given the above, we recommend that the EPC Gen 2 standard be amended to require that a passive UHF RFID tag include a user interface enabling consumers to detect any tags attached to the merchandise they purchase, and to interfere with the tags’ behavior if they so choose. The most obvious realization of this user interface is the integration of NFC high-frequency (HF) RFID technology in the UHF RFID transponder.

We know that the Class 1 Gen 2 standard was recently revised, and that the combination of UHF and NFC RFID technology is not a new idea (see GS1 Ratifies EPC GEN2V2, Adds Security Features, More Memory). To the best of our knowledge, however, there have been no attempts to provide users with a way to protect privacy by directly communicating with a transponder. In our opinion, the integration of this capability in the future protocol would bring a revolutionary breakthrough in the technology’s further spread, by alleviating consumer fears.

It is worth investing in the feasibility of the proposed transponder (hereby called a “UI-TAG”), in terms of the antennas’ placement on the carrier, the integration of the NFC UHF chips and the protocol’s proper extension.

With regard to the antennas, a tag that places the standard transponder of the UHF RFID and NFC technology on a common surface is already available on the market, so the antennas would operate close to each other at all times. Of course, the goal would be to minimize any eventual increase to the carrier surface’s dimensions as a result of this integration. Antenna designers, however, should be able to solve this task.

Similarly, the integration of chips can be solved using current technology. Compared with the approximately 20,000 transistors used for chips during the implementation of the transponder-side protocol of the first-generation Class1 standard, the Class 1 Gen 2 standard has requested five times as many transistors. In fact, RFID chips containing nearly one million transistors exist at present. In this case, the scale is only doubled, so even if we did not trust good old Moore’s law, the chip integration would result in a minimal increase of dimensions—and remember, the transponder’s ultimate size is by no means determined by the size of the chip, but that of the antenna. Last year, for example, Neology announced that it had developed a dual-frequency transponder (see Neology Adds NFC to UHF RFID Transponders).

We further propose that a simple extension be made to the UHF RFID standard, in order to provide the transponder with an internal flag, the status of which would specify whether the transponder should respond to any query in the UHF range. However, the flag’s setting and alteration would be performed only on the NFC side. Furthermore, the response or silence should depend on the outcome of communication with the user on the NFC side. Of course, it is necessary to define, on the NFC side, the functions by which this flag can be set, or the corresponding logical value can be generated for the UHF response.

What’s more, the adoption of NFC UHF tags could possibly lead to new application areas. By implementing reader broadcasting—a function not used so far with passive UHF RFID technology—a UHF reader could broadcast a message that, unlike the current protocols, would not expect any direct response from the tag. Instead, the reader’s message would simply inform the tag, “Here’s who I am and here’s what I want to do.” According to today’s EPC Gen 2 protocol, a tag cannot do anything with this message, but if a UI-TAG were realized, the new mode of operation could be interpreted—the individual user could read this message via NFC. In this way, the broadcasting of either an individual identifier or a link—or even a complex data structure describing a service or business offer—can be propagated, on the basis of which the transponder’s owner can then decide if he or she would like to use this information.

We also note—having eliminated the hazards and offering only benefits to consumers—that it would be similarly worth manufacturing the tags used inherently in the NFC applications equipped with a UHF interface (in that case, perhaps “UNI-TAG” would be a better name). Imagine, for example, that NFC-enabled mobile phones in the future might have such a transponder. This could be employed to extend the read range of the phone’s NFC technology to a few meters, thereby enabling a consumer to use his or her phone’s NFC function to access information provided by UHF RFID technology. It is not just a solution for providing business offers, but also, for example, for calling attention to hazards, or for providing information to the vision-impaired.

Overall, we can state that integration would not pose an unsolvable problem on the protocol level. We have begun the detailed development of this protocol simultaneously with drafting our proposal, but we also welcome other organizations interested in cooperation. As part of this work, we will, of course, clearly define the eligibility rules to influence the UI-TAG’s behavior, including situations in which the transponder linked to an object would change hands along with that product.

Finally, we again emphasize that the implementation of what we set out in our proposal is in the interest of all those involved with RFID technology—even if making it a reality might pose certain difficulties for standard-setting organizations, as well as for RFID manufacturers. The UI-TAG concept has the potential to significantly improve RFID’s social acceptance, and thus to open new horizons for the technology’s future use.

József Bánlaki ( is the director of the Internet of Things (IoT) Research Center at Eszterházy Károly College, in Eger, Hungary. Miklós Hoffmann ( is a professor at Eszterházy Károly College, and the head of the college’s department of mathematics. Tibor Juhász ( is an associate professor at Eszterházy Károly College. Their RFID research project was supported by the European Union and the State of Hungary, co-financed by the European Social Fund in the framework of TÁMOP-4.2.2.C-11/1/KONV-2012-0014.