RFID Tagging
What is RFID?
A historical perspective is useful in explaining what is RFID. At one time, products were accounted for and tracked through the supply chain by people reading box labels and comparing that information to paper records--contracts, manifests, packing lists, etc.As computers began to be more available, humans read box labels and visually compared that information with computerized records, either on a computer screen or more frequently still with paper records that were printed from the computers.
Then the barcode arrived. Through the use of standardized, computer-readable symbols suppliers were able to communicate to participants in the supply chain information about the box contents, contract and other data. Now humans had a way to automatically read the data, instantly compare it to computerized records, update the computerized records, and receive feedback such as next routing steps.
RFID is simply another medium to contain this same box information. It fills the same purpose in the supply chain of communicating in a standardized way information about a shipping unit to participants in the supply chain, allowing immediate computer queries and updates. One of the main differences between the use of RFID and barcodes is that barcodes rely on reflected light beams to read information. RFID relies on reflected radio waves. This means that RFID tags do not have to be in direct line of sight to the RFID readers. This means that shipment units can be presented to the RFID readers in many different orientations--upside down, sideways, etc.. Another major difference is that RFID technology permits thousands of RFID tags to be read in the time that is required to read a single barcode by most barcode readers. Combine these two features, the ability to read without direct line of sight and the ability to read many at once, and you have a technology that is well-suited for shipping and receiving applications.
How does RFID work?
More technical explanations can be found elsewhere; this is a layman's explanation. RFID stands for Radio Frequency IDentification. An RFID tag that is applied to boxes and pallets consists of an integrated circuit ("IC" or microchip, also called a computer chip) and an antenna. These are applied to some sort of backing. An RFID reader transmits a radio signal on the frequency to which the RFID tag is manufactured to respond. The RFID tag picks up the transmitted radio signal, alters it by adding to the signal the unique data stored on the RFID tag, and sends the radio signal back to the RFID reader.The data is stored (encoded) on the RFID tag either when the RFID tag is manufactured, or much more commonly when data is printed on the RFID tag surface. In DOD applications, a supplier prints a label, such as an Exterior Container or Military Shipping Label, on an RFID-enabled printer. These printers have RFID readers installed within them so that they can print the label and encode the RFID tag at the same time. The software that prints the label is responsible to ensure that the right data is sent to the printer, specifically that the data encoded to the RFID tag is unique and never duplicated.
| Sample Labels with RFID |
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| RFID Military Shipping Label |
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| RFID Exterior Container Label |
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| RFID & UID Exterior Container Label |
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| Generic RFID Exterior Container Label |
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When to Use RFID Tagging
Your contract should tell you if you are required to apply RFID tagging to your shipment. However, you may need to comply with RFID requirements even if the requirement is not mentioned in your contract. The criteria for RFID compliance is spelled out in the DFARS (Defense Federal Acquisition Regulation Supplement).Military Standard 129 says:
- Unless otherwise specified in the contract or solicitation, DoD and contractors/vendors shipping or delivering to the DoD will use passive RFID tags that comply with the EPCglobal Generation 2, Class 1 RFID tag specifications. (Mil-Std 129, para 4.9.1)
- Passive RFID tags shall be applied to case shipments and palletized unit load shipments. (Mil-Std 129, para 4.9.1.a)
- Bulk commodities shall not be tagged in accordance with passive RFID tagging requirements. (Mil-Std 129, para 4.9.1.b)
Where to Place RFID Tags
The passive RFID tag may be integrated with the military or commercial shipping label (RFID-enabled address label) or they may be placed in separate locations on the shipment. (Mil-Std 129, para 4.9.2)Individual Shipping Containers and Palletized Unit Loads
RFID tags that are integrated with other shipping labels should follow the guidelines for placement of those shipping labels. (Mil-Std 129, para 4.9.2.1.a)RFID tags that are not integrated with other shipping labels should be placed within the same boundary area as prescribed for address labels. (Mil-Std 129, para 4.9.2.1.b)
In addition, RFID tags should be placed where there is a minimum risk of damage, easy access to barcode symbols, and highest potential for successful RFID reads. RFID tags should not be placed over a carton seam nor should sealing tape or bands be placed over the tag that interfers with reading of barcodes or the RFID tag. RFID tags should not overlap other RFID tags. RFID tags for pallets should not be attached directly to an exterior container. (Mil-Std 129, para 4.9.2.1)
Exterior Containers within a Palletized Unit Load
The RFID tag should be affixed at a suitable location where there is a minimum risk of damage and the highest potential for successful passive RFID tag interrogation. (Mil-Std 129, para 4.9.2.2)RFID Tagging Munitions/Explosives
See Mil-Std 129, para 4.9.3 for more information.Other References
DOD RFID website (http://www.acq.osd.mil/log/rfid/index.htm)





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