What is RFID?

RFID stands for radio frequency identification. It is an automatic identification technology whereby data encoded in an RFID tag or “smart label” is captured by a reader using radio waves. Put simply, RFID is similar to bar code technology but uses radio waves to capture data from tags, rather than scanning the bar codes on a label. RFID does not require the tag or label to be seen to read its stored data—that's one of the key characteristics of an RFID system. 

What is an RFID tag?

RFID tags consist of an integrated circuit attached to an antenna—typically a small coil of wires—plus some protective packaging (like a plastic card) as determined by the application requirements. RFID tags can come in many forms and sizes. Some can be as small as a grain of rice. Data is stored in the IC and transmitted through the antenna to a reader. RFID tags are either “passive” (no battery) or “active” (self-powered by a battery). Tags also can be read-only (stored data can be read but not changed), read/write (stored data can be altered or re-written), or a combination, in which some data is permanently stored while other memory is left accessible for later encoding and updates.

What is an RFID reader?

A reader is basically a radio frequency (RF) transmitter and receiver, controlled by a microprocessor or digital signal processor. The reader, using an attached antenna, captures data from tags then passes the data to a computer for processing. As with tags, readers come in a wide range of sizes and offer different features. Readers can be affixed in a stationary position (for example, beside a conveyor belt in a factory or dock doors in a warehouse), portable (integrated into a mobile computer that also might be used for scanning bar codes), or even embedded in electronic equipment such as print-on-demand label printers.

How does RFID work?

Information is sent to and read from RFID tags by a reader using radio waves. Data collected from tags is then passed through familiar communication interfaces (cable or wireless) to host computer systems in the same manner that data scanned from bar code labels is captured and passed to computer systems for interpretation, storage, and action.

How does RFID differ from bar coding?

Conceptually, bar coding and RFID are quite similar; both are intended to provide rapid and reliable item identification and tracking capabilities. The primary difference between the two technologies is that bar coding scans a printed label with optical laser or imaging technology, while RFID scans, or interrogates, a tag using radio frequency signals. Because of the low cost of bar code labels, established standards, and global deployment, bar coding is widely accepted while, in general, RFID has been limited to niche applications. Furthermore, just as there are different bar code symbologies in use today, there are different RFID standards regarding the way data is captured from tags—the RF communications protocol.

Will RFID replace bar codes?

These technologies are NOT mutually exclusive, nor will one replace the other. They are both enabling technologies with different physical attributes. Bar codes utilize one-way, serialized and periodic data. RFID utilizes two-way, parallel, and real-time data.

Leading-thinking companies are using their current bar code systems to benchmark RFID technology in order to gauge impact on performance. This baseline is a crucial measure in determining the effectiveness of a new RFID system. Separating the data aspect (EPC, for example) of RFID systems from the operational aspect is a very good way to start to learn the physical properties of RFID. The determination of when to use RFID technologies instead of bar codes should be driven by the business need and the extent to which RFID can improve an
existing business process. Basically, RFID should be deployed just like any other technology—when the benefits justify the cost and effort involved in implementing it.