Apr 06, 2003April 7, 2003 - Talk to people in the United States and they will tell you that North America is way ahead of the rest of the world in adopting radio frequency identification technology. Talk to people in Europe and you will hear that Europe is leading the way. There are no statistics, but anecdotally, it appears that European companies are ahead of the rest of the world. If it wants to stay there, the European Union needs to change its regulations on UHF readers.
For those unfamiliar with this arcane world of communications regulations, most governments around the world not only allocate certain bands of the radio frequency spectrum for certain uses (from automatic garage door openers to cell phones), they also limit the power of these devices. That's to reduce the likelihood that one wireless device will interfere with another.
In the US, a UHF reader is allowed to put out four watts of what's called "effective Isotropic Radiated Power". The EU uses Effective Radiated Power to measure output. But the results it that readers operating in the EU can only put out about one-fifth of the output of a US reader. That means that UHF tags can be read from a much greater distance in the US than in Europe. This is likely to have an impact on how quickly Europe adopts UHF systems, particularly the Auto-ID Center's Electronic Product Code (see Will Europe Embrace the EPC?).
Another problem is Europe doesn't allow the reader to hop between frequencies. In the US, readers send out waves between 902 and 928 MHz, and tag antennas are tuned to this band. There are two main benefits to this approach. It reduces nulls, or blind spots, in the read field. Since the null changes slightly each time you change frequencies, you have a better chance of reading all stationary tags in the field.
The other benefit of frequency hopping is there is less interference with other readers. If you have an environment where readers are in close proximity to one another, they are a less likely to interfere with each other if they are switching frequencies randomly. They will only interfere with one another when they send out signals at the same or nearly the same frequency. To prevent interference in Europe, readers have "time share." That is, one has to go off while another goes on to avoid interference.
These limitations are not insurmountable. In fact, sources tell RFID Journal that one European company will soon make a major announcement regarding plans to use UHF tags on individual apparel items. But it does mean that that European companies are going to have less incentive to use RFID in the supply chain because shorter read ranges mean you need to install more readers and you therefore have higher expenses.
The EU has proposed changes the UHF regulations to allow for two watts of power output and 10 channels for frequency hopping. We'd like to see those changes implemented as quickly as possible. Government regulators tend to move at their own pace, but the RFID world is developing very quickly. And nothing would help European companies maintain their competitive edge in this area than changing these restrictions.
Mark Roberti is the Editor of RFID Journal. If you would like to comment on this article, send e-mail to
mroberti@rfidjournal.com.
