By Mike Marsh,Trolley Scan(Pty) Ltd
Without a doubt the answer is Yes!!!
The question is although it is technical viable, what are the issues governing the commercial viability of such a system??
Radio Frequency Identification transponders (RFID) can be attached to individual items to be identified, and the identities of those transponders can be read by a reader which passes the information onto a computer, so giving the computer "vision" within the volume scanned by the reader. As the system uses radio communication for passing data, it is not necessary for the transponders to be in direct line of sight of the reader such as with barcoding, but just to be in radio communication with the reader.
Another possible method of bringing order to the transponder to reader
communications, is to use the reader to control the communications by passing
messages from the reader to the specific transponder, each of which requires
an onboard receiver to decode the incoming message, and a unique address
or identity to monitor the incoming messages and determine when it is being
addressed. In this situation, the transponders still need tuned circuitry
in their receivers to monitor the read to transponder communications, but
the signals are much stronger than those of the transponder to tranponder
communications mentioned above requiring simpler circuitry. Typically in
this mode, the reader polls the transponder, by calling its number and
seeing if it answers, or by letting the transponders broadcast randomly,
and once an identity is detected to broadcast that identity and either
transfer information to the transponder or pass instructions to it to cease
communications to free the communication channel for other devices.
In order to design a system that could be suitable for barcode replacement, it is necessary to develop a protocol that can allow for ordered communication without having onboard receivers on the transponders.
In 1991, the author, while working for a research laboratory of the
South African Government, invented just such a protocol which was patented
and made available for licensing by world companies.
In 1994 the author left government service and started his own small consulting company with a partner. In 1998 they took the protocol issue closer to the ultra low cost transponder system by inventing a patenting a more simple protocol called Trolleyponder®. This has been offered to companies around the world who wish to become involved in very low cost transponder systems to replace barcoding.
For both the last two systems, by using a system called backscatter
modulation, patented in the US in 1969, whereby the transponders reflect
varying amounts of the energising field by modifying their antenna matching
impedances, it is possible to make a transponder that is independant of
frequency, in that the same active components can operate from 100 MHz
to 2.5GHz, just dependent on the antenna resonance and matching. In addition
very wide manufacturing tolerances can be allowed, further increasing yields
for manufacturers and therefore lowering the costs. In the protocols invented
by the author, the actual identity of the tag does not play a part in the
recognition of a tag, and it is possible to have many tags with the same
identity such as might occur at a retailer with all items of the same description
carrying the same product code.
In order to have a transponder system that is going to cost a few cents to manufacture, the transponder has to extract its power from an energising field as a battery system would be too expensive. This implies that the transponder needs to be powered up from the energising field throughout the reading session, so that it can remember its status on whether or not it was heard.
Unfortunately it is very difficult to generate a uniform radio frequency energising field in a real situation. The interation between direct and reflected rays from the same source interact, causing RF energy fluctuations throughout the reading volume. In the original development work, the author invented a system of providing the energising field at a number of different frequencies, from different antennas often with different polarizartions, so that no matter what orientation or location the transponder was in the reading volume, it would be in communication with the reader on at least one frequency. Such a system would typically operate on three frequencies, that needed to be sufficiently seperated so that filters could remove the energising frequency of one set from swamping the communications on another set.
In 1998, the author and his partner filed a provisional patent application providing multi axis energising and scanning, while only using a single frequency. This now means that for trolley scannning, only a single frequency will be needed despite the complex RF situation.
The technology is now available to solve this application, the tags are produceable at reasonable costs, but still the scanning trolley has not made an appearance, why?
The reason 100 million is an important planning number, is:
Although 100 million transponders might appear a large number, it is in fact trivial in an industry where just one of the smaller mail courier's use more than 600 million tags per annum, where 6 000 million EAS tags are sold in Europe alone, and where the grocery industry world wide is estimated to use 10 million million (1014) per annum.
Cost price versus selling price
The cost price of the transponder relates to the components incorporated in the transponder, while the selling price relates to the price the market is prepared to pay, especially when the market demand is higher than the supply. The way to bring down the selling price is to increase the competition and supply, especially as this one technology has application in many different industries in almost all countries in the world.
Towards the grocery retail market
For retailing, it is likely that this technology would first appear
on caselots, being used throughout the entire manufacturing, warehousing
and logistics chain to track the progress of the cases, including the benefits
of the inbuilt Electronic Article Surveillance features to stop pilferage.
Its benefit to the retail store owner would be at the back door, where
they receive the caselots for breaking down and stocking their shelves.
The retailer would only be able to switch to this technology once all his suppliers have switched and supplies have increased to allow for sufficient transponders for marking at unit level.
What is Trolley Scan trying to do to make this happen
The bottlenecks are the lack of suppliers of transponders and companies becoming involved in delivering and customising the technology to the end users needs. To facilitate the growth of this technology, Trolley Scan are
Besides the issue of encouraging companies and investors to become involved as licensees and value added resellers, the next hurdle will be to encourage the semiconductor foundries, who seldom have a single product that requires such volumes, to increase capacity to supply sufficient transponders.
"One day the world will have scanning trolleys, it is just a matter of time"
November 2003 - Walmart have announced that they require their top 100 suppliers to switch to RFID by 2006. An extention of the global barcoding numbering system managed by the EAN/UCC, has been created for RFID, which is known as EPC.
Trolleyponder®/EcoTag® details are available at trolleyscan.com
If you want to contact the editor about additional information or questions,
send mail to The editor, Transponder News
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