The world at present is desperate for some form of standard with many companies who wish to become RFID producers wanting to be EPC-compliant.
The EPC goals are based around two components, a data standard used in labelling products and a common RFID protocol standard allowing interoperability between all manufacturers.
The data standard has a core around the very successful numbering system used by the EAN/UCC in about 180 countries worldwide. This currently is implemented on the bar codes used in labelling retail products where the number has three components - one for the country of manufacture, one for the producer in that country and one for the product in the producer's catalogue. These components are combined to form a 13-digit number that uniquely identifies each range of products sold in a retail store.
The RFID protocols cover the technical/physical features of the transponder/reader. EPC had tried to steer clear of all existing patents so that they could have a licence-free situation. The first versions that were implemented were called Class 0 and Class 1, catering for different stages of technical development in the transponder chip process. Recently, the manufacturers who had decided to produce solutions decided to abandon Class 0 and Class 1, and chose to develop a new version called Class 2. From five initial proposals, two went through to the next round and recently, these have been combined into a new single Class 2 proposal.
Introducing a new Class means huge investments in chip design and delays of at least six months while new chips are designed and debugged. It also kills any further developments in Class 0 and Class 1 which are now instantaneously obsolete.
A new complication has now arisen in that a US company is claiming the Class 2 versions will infringe patents it holds on RF Protocols and it is warning everybody that they will have to licence the protocol, hence nullifying all EPC's efforts to bypass patented technology. In fact, Class 2 should never exist, as it is still a reader-talks-first protocol that will prove to be unsuitable for an application where many readers are required to operate in close proximity.
To explain the difference between reader-talks-first and tag-talks-first protocols - imagine you were at a picnic in a quiet park trying to whisper to your companion, but close by, you have another group of picnickers with a radio playing rock music full blast; this is the situation with reader talks first. Now imagine that back in the radio station the music source is disconnected or comes to an end of the music track - the radio is still receiving a signal but is quiet - that is tag-talks-first. In both situations the radio is still broadcasting a signal, the difference being the amount of interference it causes.
By the time EPC accepts the final protocol - possibly a Class 6 ? - it will have to be a tag-talks-first protocol purely on the need to coexist with other readers. However, whether EPC manages to avoid all the patented protocols - which could take about five years to move through the patenting offices - remains to be seen.
It is going to be a long road ahead before there is a practical EPC RF protocol.
For more information contact Mike Marsh, Trolley Scan, 011 648 2087.
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