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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.
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