Three frequency ranges are generally distinguished for RFID systems: low, intermediate (medium) and high.
Characteristics of low- frequency (100 to 500 kHz) bands include short- to medium-read range, inexpensive, low reading speed. Typical applications include access control, animal identification, inventory control and car immobilizers.
Characteristics of intermediate-frequency (10 to 15 MHz) bands include short- to medium-read range, potentially inexpensive, medium reading speed. Applications include access control and smart cards.
Characteristics of high-frequency (850 to 950 MHz, 2.4 to 5.8 GHz) bands include long-read range, high reading speed, expensive, line of sight required. Applications include railroad car monitoring and toll collection systems.
A degree of uniformity is being sought for carrier frequency usage, through three regulatory areas, Europe and Africa (Region 1), North and South America (Region 2) and Far East and Australia (Region 3). Each country manages its frequency allocations within the guidelines set out by the three regions. Unfortunately, there has been little or no consistency over time with the allocation of frequency, and so there are few frequencies that are available on a global basis for the technology. This will change with time, as countries are required to try to achieve some uniformity by the year 2010.
Three carrier frequencies receiving early attention as representative of the low, intermediate, and high ranges are 125kHz, 13.56 MHz and 2.45 GHz. There are eight frequency bands, however, in use around the world for RFID applications. Not all the countries in the world have access to all the frequency bands listed above, as some countries have assigned these bands to other users. Within each country and within each frequency range there are specific regulations that govern the use of the frequency. These regulations may apply to power levels and interference as well as frequency tolerances. In the less than 135kHz, a wide range of products is available to suit a range of applications, including animal tagging, access control, and track and trace ability. Transponder systems, which operate in this band, do not need to be licensed in many countries
About the author: Rod Harrison, Cornerstone Solutions, can be reached at 260-496-8259.
Recent articles:
Defense Department Scales Down RFID Plan; http://story.news.yahoo.com/news?tmpl=story&u=/cmp/20031209/tc_cmp/16600185
Defense Dept. working to resolve RFID standards issue; http://www.computerworld.com/softwaretopics/erp/story/0,10801,87808,00.html
Wal-Mart to begin phased RFID tag rollout next year; http://www.computing.co.uk/News/1148506.html
Wal-Mart's RFID Deadline: A Chunky Mess; http://www.eweek.com/article2/0,4149,1414163,00.asp
AmEx Expands RFID Payment Trial; http://www.rfidjournal.com/article/articleview/505/1/1/.html
Military's RFID Alternative: IPv6; http://www.rfidjournal.com/article/view/609.html
RFID is big but nobody understands the costs; http://www.usingrfid.com/news/read.asp?lc=k19752px58zu.html
Other articles in this series:
