Integrating Additional Data

RFID tags are not intelligent technology: Unlike a smart card, they do not have real processors. The tag is a kind of electrically erasable PROM (EEPROM) that permanently stores several bytes of information. In practice, every provider uses this storage as they want: no standardization organization exists to keep them from storing their data in ancient Talmudic Aramaic or as Rumba dance step instructions. Although I exaggerate, in practical deployments, something like this type of behavior does occur: One of my customers stores serialized Java objects on tags.

Before considering frequently used methods, you need to take a look at general considerations. The information stored in tags can be divided into two groups: tags that only contain information about the element they describe or tags that store user data. The advantage of the first approach is that such a tag is comparatively inexpensive, requiring little memory; write once, read often works perfectly well. The disadvantage of such a tag, however, is that you need an Internet connection to evaluate the information, which increases costs.

The second and conceptually completely different approach of placing user data on the tags has the advantage that you can also interact with the tag offline. On the other hand, they are more complex, and not every tag reader is capable of writing such data.

In the Footsteps of Oracle

Of all the large IT companies, Oracle is the most active when it comes to RFID. Among other things, the company provides a whitepaper [3] in which various snippets of information on the structure of the company's own RFID solutions can be found. Of particular interest is a reference to the FSTC-compatible tags. The Financial Services Technology Consortium (FSTC) is a standardization organization, who defines various technology standards for the American banking market. The specification documents are difficult to find; however, you can find a list of the criteria that describe FSTC-compatible tags online [4]. These specifications include, among others, that:

• tags must be precoded and installed by the original equipment manufacturer (OEM),
• human-readable text on the tags is the same as the information encoded in them,
• each has a one- or two-dimensional barcode,
• tags must be able to survive minor collisions with other goods, and
• tags must be able to be attached to the server without penetrating the surface.

You can source such tags from Oracle, but they can also be found on some IBM power servers. The tags, also known as Gen 2 RFID tags, are estimated to cost between $20 and $30 per device. They come with at least 96 bytes but can have 1KB or more of total memory capacity.

Of particular interest is that the memory is divided into banks, much like older computers. Bank zero is the "reserved memory," an area in which, among other things, the "kill password" is hidden. This command permanently disables an FSTC tag and can be used, for example, to turn off a tag before the device is sold. The EPC and TID codes contain chip-specific information. TID is a code branded by the manufacturer that uniquely identifies the individual tag (Tag ID). Meanwhile, the EPC contains the electronic product code, known from other merchandise management systems.

Bottom Line

Companies need to keep track of their assets, and RFID can be a solution. In addition to making it easier to find goods, small tags ensure that casual theft is avoided. In addition to the not inconsiderable costs, however, the confusing market environment speaks against RFID-based asset tracking.

The best approach is therefore to contact a solution provider as the first step. The higher cost of the individual tags are – especially in the beginning – a good investment, because the really tricky part of an RFID system lies in the intelligence or software.