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The Electronic Product Code

The Basics of RFID Tags

Bringing Down the Costs of Tags

Understanding Radio Waves

The Reader


Object Name Service

Physical Markup Language


An in-depth look at the new network
The Auto-ID Center and its sponsors are working to develop flexible tags and readers and to bring the cost of the hardware down to a level where RFID can be used to track individual items. And we're working to create a new, open, global network that will allow companies to take advantage of low-cost RFID tags. Below, we explain the key elements of our approach to automatic identification in greater depth.

The Electronic Product Code
The Auto-ID Center has proposed a new Electronic Product Code as the next standard for identifying products. Our goal is not to replace existing bar code standards, but rather to create a migration path for companies to move from established standards for bar codes to the new EPC. To encourage this evolution, we have adopted the basic structures of the Global Trade Item Number (GTIN), an umbrella group under which virtually all existing bar codes fall. There's no guarantee that the world will adopt the EPC, but our proposal already has the support of the Uniform Code Council and EAN International, the two main bodies that oversee international bar code standards. We're also working with other national and international trade groups and standard bodies.

How it works
The EPC is a number made up of a header and three sets of data, as shown in the above figure. The header identifies the EPC's version number - this allows for different lengths or types of EPC later on. The second part of the number identifies the EPC Manager - most likely the manufacturer of the product the EPC is attached to - for example 'The Coca-Cola Company'. The third, called object class, refers to the exact type of product, most often the Stock Keeping Unit - for example 'Diet Coke 330 ml can, US version'. The fourth is the serial number, unique to the item - this tells us exactly which 330 ml can of Diet Coke we are referring to. This makes it possible, for example, to quickly find products that might be nearing their expiration date.

Types of EPCs
The Auto-ID Center has proposed EPCs of 64- and 96 bits. Eventually, there could be more. The 96-bit number is the one we think should be most common. We chose 96 bits as a compromise between the desire to ensure that all objects have a unique EPC and the need to keep the cost of the tag down. The 96-bit EPC provides unique identifiers for 268 million companies. Each manufacturer can have 16 million object classes and 68 billion serial numbers in each class, more than enough to cover all products manufactured worldwide for years to come. Since there is no need for that many serial numbers at this time, we propose an interim 64-bit code. The smaller code will help keep the price of the RFID chips down initially, while providing more than enough unique EPCs for current needs.