Many modern technologies give the impression they work by magic, particularly
when they operate automatically and their mechanisms are invisible. A technology
called RFID (radio frequency identification), which is relatively new to the
mass market, has exactly this characteristic and for many people seems a lot
like magic. RFID is an electronic tagging technology (see figure 1) that allows
an object, place, or person to be automatically identified at a distance without
a direct line-of-sight, using an electromagnetic challenge/response exchange.
Typical applications include labeling products for rapid checkout at a point-of-sale
terminal, inventory tracking, animal tagging, timing marathon runners, secure
automobile keys, and access control for secure facilities.
In fact, various forms of crude RFID have been used since World War II. In the
1960s the technology became more practical, but the applications since then
have resulted in relatively small tag deployments in narrow high-value areas
without much public visibility. Also, given a tag’s small size and ability
to be hidden or molded into the casing of a product, some people may have encountered
RFID without realizing it was present.
In the last couple of years many RFID stories have appeared in the popular press.
Why is RFID making a splash now, given that the idea is at least 40 years old?
Most technologies have a window of opportunity for deployment, which is related
to the scope of the problem it solves, the maturity of the technology, and the
cost of deployment. On all three of these points the world has changed over
the past 40 years. Inventory tracking is now necessary on an unprecedented scale
to support growing consumer markets at low operating costs and to remain price
competitive despite the relatively high labor cost in the developed countries.
Furthermore, the components used to build the tags and tag readers have become
more sophisticated. Today, they provide greater functionality, reading range,
and speed of data transfer. As a result, they support the ability to accurately
read a large number of co-located tags at the same time. Standards also play
a role—an important new standard created by the former Auto-ID Center
(whose work is now being carried forward by the not-for-profit EPCglobal) has
recently brought together a number of influential organizations such as Wal-Mart,
Tesco (UK), and the U.S. Department of Defense (DoD), all of which recognize
the opportunity RFID brings to improve operational efficiencies.
Lastly, the ultimate incentive for deployment of a technology is cost. When
the benefits and cost savings brought about by the technology are greater than
the deployment cost, the time is right. Since tags would most often be attached
to large inventories of relatively inexpensive products, the tags need to be
inexpensive. Some analysts say a tag must cost less than 5 cents (others below
1 cent) for the technology to be truly competitive. By comparison, existing
tagging technologies such as bar-code systems involve little more than the very
low cost of printing lines on packaging. At present, RFID tags are in the 50-cent
range for small quantities, a number that could be reduced to the target price
if their use were to grow as expected.
Initially, commercial deployment is likely to focus on pallet- or crate-level
tracking in a warehouse, and depending on its success, may lead to item-level
tracking in the future. RFID could improve the efficiency of warehouse management
considerably. RFID tags would allow crate identities to be checked at a distance
when entering or leaving the building, whether or not the tag is directly visible.
A bar code used in the same application could well be facing the wrong direction,
making it impossible to scan automatically. Once RFID has proved beneficial
and has been well established, economies of scale such as mass production should
help bring down the price. This would enable item-level tracking for high-value
goods, and perhaps eventually, even tracking low-value items.
There is clearly risk involved in investing in the infrastructure before it
is truly adopted on a national or global scale, but at the same time the costs
will not decrease until that risk is taken. The previously mentioned organizations
are engaging in serious trials, and other big chain stores can be expected to
follow. These companies have enough presence in their market segments that they
can make the opportunity a reality. Once their own warehouses adopt the technology,
their suppliers will also be required to follow suit, accelerating the adoption
process. These possibilities have drawn a lot of press attention, inspiring
a flurry of articles and discussion on the Internet.
LOOKING INSIDE RFID
Before considering the issues raised by this technology, it is helpful to understand
the basics of its operation. An RFID system is composed of readers and tags.
Readers generate signals that are dual purpose: they provide power for a tag,
and they create an interrogation signal. A tag captures the energy it receives
from a reader to supply its own power and then executes commands sent by the
reader. The simplest command results in the tag sending back a signal containing
a unique digital ID (e.g., the EPC-96 standard uses 96 bits) that can be looked
up in a database available to the reader to determine its identity, perhaps
expressed as a name, manufacturer, SKU (stock keeping unit) number, and cost.
An RFID tag is built from three components:
• Antenna
• Silicon chip
• Substrate or encapsulation material
These tags are generally referred to as passive because they require no batteries
or maintenance. Tag operation varies according to the frequency at which the
tag operates. Historically, four common ISM (industrial, scientific, medical)
frequency bands have been used: 128 kilohertz, 13.56 megahertz, 915 megahertz,
and 2.45 gigahertz (see figure 2).
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