• United States
by John Fowler and Dirk Heyman, special to Network World

RFID takes stock of supply chain

Jun 09, 20034 mins

Radio frequency identification devices rev up retail

The use of radio frequency identification devices – tags, cards or labels – continues to grow as businesses realize the many advantages of the technology. Organizations such as the Auto-ID Center are furthering the adoption of RFID devices by developing standards and protocols that enable IT systems to identify and track virtually any physical object.

Using radio waves to track objects and provide near-real-time views of product status and location, RFID makes supply chains more efficient. Rather than waiting for monthly or quarterly reports, retailers can get nearly instantaneous data that tells them which products have been sold, and how much remains on shelves, in warehouses and distribution centers. This information aids inventory control and distribution channel management, and reduces costs.

A tag consists of an RFID chip and antenna. There are three types of tags – active, semipassive and passive. Current development is focused primarily on passive RFID tags because these devices are far less expensive to manufacture and deploy. The cost is coming down to pennies per tag, depending on capabilities, such as size and function.

Passive tags use radio waves for operation and communication. Signals are available only within the field of a reader, which is usually about 10 feet. This type of tag is useful for items that can be read from short ranges, such as cases filled with disposable razors or packs of replacement blades.

RFID chips can be read-only or read-write, depending on application requirements. The tags use Electrically Erasable Programmable Read-Only Memory, which lets them be written to via a special electronic process. For all practical purposes, the tag becomes read-only after it has been manufactured. The Auto-ID specifications, however, include a kill command that allows tracking to be stopped in appropriate circumstances.

An Electronic Product Code (EPC) identifies the object, and all data related to the object (product, case, pallet) is stored on servers on the Internet. The EPC system automatically links the EPC with the correct database, and manufacturers and retailers can consult, manage and change that data if they have the right privileges.

Once a tag is attached to a product or device, an RFID reader can read information stored on the tag. The most common method readers use to communicate with passive tags at close range is called inductive coupling – the same technology used for key card entry at many corporations. A coiled antenna on the reader creates a magnetic field, and the tag draws enough energy from this field to send its unique information to the reader.

The Auto-ID Center has worked on the creation of global standards for the EPC system, and plans to announce the first standards in September at the EPC-Symposium in Chicago. The Uniform Code Council and EAN International formed Auto-ID, a not-for-profit organization dedicated to developing and overseeing the EPC standards.

Here are the key EPC system standards:

lEPC: A unique number that identifies an object.

lEPC Manager: Defines the owner of the data, such as the manufacturer.

lHeader: Defines the rest of the code and tag.

lObject class: Defines the item reference, such as stock-keeping unit number.

lObject naming service: Translates the EPC code into an Internet address.

lPhysical markup language: Describes the object (such as what it is, where and when it has been sent).

lSavant: Software that aggregates and processes RFID data.

lSerial number: Unique number for each object.

lTag and reader specifications: Minimum set of specifications for interoperability.

With the ability to update information, simultaneously read and identify multiple tags, and operate in a variety of harsh conditions, the EPC system is ideal for tracking products, boxes and pallets in near real time. This creates the needed transparency to improve the supply chain and therefore trade.

Fowler is CTO of software for Sun, and Heyman is industry head of Sun’s Consumer Products Industries Group and chairman of the Auto-ID Center’s technology board. They can be reached at and, respectively.