Since most countries have allocated the minimum of spectrum for radio frequency identification (RFID) use, companies need to exercise caution when selecting the system they put in place. 

The situation is exacerbated in places like South Africa and most European countries by the fact the the GSM cellular network occupies part of the spectrum that would normally be available for RFID.
Among the various RFID protocols that companies can choose from, some could end up consuming more spectrum than is available and therefore not act as expected.
Trolley Scan, a Johannesburg-based RFID technology developer, has raised these and other issues in a new report on the measurement of UHF radio spectrum usage for different air-protocols in use with different RFID designs.
RFID uses part of the radio spectrum to operate, usually within the 860MHz and 960MHz band, and some countries could find that the available spectrum isn't enough.
"The number of frequencies that can be used by a particular class of application is part of a spectrum plan that is drawn up by the regulators in a particular country," says Mike Marsh, MD of Trolley Scan, in the white paper.
"The spectrum plan is based on providing frequencies for operation of many different applications – from applications like cellphones, RFID, radio stations, TV stations, remote contollers and two-way radio communications.
"In most countries, the available spectrum for RFID is as narrow as 200kHz while in a very few others it is as wide as 26MHz."
Marsh explains that there are two broad RFID protocols: tag-talks-first, which operates at high speed and causes little interference; and reader-talks-first, which he characterises as slow, unreliable and requiring a wide spectrum.
"RFID needs to have acceptable operating range, should be an affordable technology, should be reliable and should be able to operate in situations where readers are in use in a close environment," Marsh writes.
"At present, RFID is in its infancy, and in few cases have situations occured where more than 10 reader systems are operatng continuously in a single warehouse. In future, the capacity of the system needs to be increased to hundreds, of not thousands, operating in the same vicinity.
"The radio spectrum is not an unlimited resource and the technology needs to adapt to the available resource.
"The results of the study allow an understanding of the issues involved and indicate why a change from certain protocols that are currently promoted needs to be made as the industry matures."