Government/Military Trends

The Basics of RFID Technology

Issue Table of Contents

The Basics of RFID Technology RFID and the Department of Defense (DoD): Impact on DoD contractors Can RFID protect the nation’s beef supply? RFID and Bar Coding Standards and Related Publications

Though in use since World War II, RFID technology is seeing renewed interest and development due, in part, to the upcoming RFID tagging requirements from the Department of Defense (DoD) and Walmart.

RFID, or Radio Frequency Identification, is the term used for technologies that leverage radio waves to identify items automatically. Typically, this happens through a stored serial number on the tag that identifies a product. The tag may also have other information, such as where the item was made, manufacture date, and other items that could be relevant for that item. The term EPC, or Electronic Product Code, is sometimes used interchangeably for RFID, but in fact, the EPC refers to the information that is on the tag – the unique item number that identifies that individual item.

RFID has two components – a microchip and an antenna. The microchip stores the EPC and other information, while the antenna provides the ability to transmit the data on the chip. Together, these components – the chip and the antenna -- constitute an RFID transponder or an RFID tag. The antenna transmits the identifying information on the chip to a RFID reader, which converts the radio waves returned from the RFID tag into a usable form of data. Sometimes, this data is connected to a database over a network. There are also hand-held and wireless applications that handle the data straight from the reader, in instances where the network is unavailable to a reader.

RFID tags are not one-size-fits all. There are different types of tags, each with its own usefulness depending on the application:

• Active tags: Currently in use by the DoD, active tags have a battery included on the tag, providing greater read range. The battery increases the basic cost per unit.
  
• Passive tags: These tags use the magnetic field generated by the RFID reader to power itself. Though the read range is lower, the price per unit is cheaper than active tags.
  
• Write once/read only tags: Once written, no information on the tag can be modified. Typically, the information on the tag would just be the EPC. To get the most benefit from these tags, they need to be connected with a database that has detailed history and information about that item. These tags are at the cheapest price point, currently $0.05/unit, making them the most appropriate for inexpensive items, such as consumer goods and small parts.
  
• Read/write RFID tags: The flexibility of read/write tags helps in remote storage situations where the relating database is out of range.

RFID vs. Barcoding: which is better?
RFID and barcoding both have their uses. In fact, industry experts anticipate that the use of barcodes will continue for many years to come, so companies that invested in barcoding technology to improve product tracking will still benefit from its use. There are some limitations of barcoding that RFID addresses:

Line-of-sight: Barcode readers can only read barcodes within line of sight, which makes physical inventory of warehouses a major hassle. In overstuffed warehouses full of inventory, each box has its own barcode. But to find out the quantity, you have to open each box. RFID tags do no require line of sight, so you don’t need to break down a pallet to find out what’s inside. Each RFID tag inside the pallet transmits to the reader, allowing an accurate determination of what’s inside.

Product data only: Barcoding only identifies the UPC. RFID tags assign a unique number to each individual item. Also, read/write RFID allows you to update information about the item as necessary; this feature could be beneficial in tracking repairs on a part, identifying specific items for recall or managing products with a dated shelf life.

Damage/removal: If a barcode label rips, becomes soiled or falls off, the scan ability is lost. RFID tags are not as susceptible to damage.

No unique identifier: Without a unique item or EPC number, it is difficult to track individual parts or items. For example the bar code on one perishable item – a meals-ready-to-eat, or a container of yogurt -- is the same as all other identical items. With a unique identifier for individual items, companies can coordinate distribution by expiration date, reducing spoilage.

RFID at this point has some use limits – it will not transmit from metal or water. International compatibility is another issue, since different countries and/or regions use different frequencies. However, there are ways to work around these limitations, and with more testing, acceptance and use of the technology – as well as the development and acceptance of an ISO standard – the limitations will be resolved.¹

^{1 References:
www.rfidjournal.com
www.epcglobal.com
Interview with Steve Halliday, President of High-Tech Aid www.high-techaid.com on 1/30/04
Interview with Charlie Milligan and Carey Hidaka from IBM, on 2/4/04}