Radio Frequency Identification (RFID)
RFID (radio frequency identification) "tags" or "transponders" are small pieces of silicon which carry programmed information. Tags are embedded in a suitable packaging and also have antennae to help send and receive RF signals carrying data packets. In some instances, specialized solutions called real-time locating systems (RTLS) are used for tracking and locating items in a building or specified area.
There are a number of RFID technologies on the market today, all of which will play some role in future tracking applications. Active RFID generally means the tags have an onboard battery. Because of the batteries, which have a lifespan of up to five years, active tags have much longer read ranges. Some tags can be read at up to 1,000 feet. The Department of Defense (DoD) has been using these tags for years as a method of locating assets, including some as big as a tank.
Passive tags have no batteries. They are "illuminated" by the power generated from a reader or interrogator. Consequently, passive tags have a much shorter read range. Some tags must even have contact with the reader. UHF (ultra-high frequency) tags fall into the passive category. UHF tags extend read ranges from 8-to-14 inches on standard passive tags to as much as 20 feet.
Within the passive tag arena, there are many offerings. Some tags are write once/read many (WORM), while others have read/write capabilities, meaning user can not only read information from a tag, they can write information to the tag at any point.
Yet another type of RFID is semi-passive or "backscatter" tags. These tags are battery-assisted and are a hybrid combination of active and passive technologies. Like their active counterparts, semi-passive tags have a longer read range than traditional passive RFID tags.
Recent RFID mandates by Wal-Mart and the DoD are accelerating RFID adoption. Another organization called EPCglobal is playing a major role in commercializing the technology in the retail arena. Under the auspices of the Uniform Code Council (UCC) and EAN, EPCglobal is taking to market the EPC (electronic product code) spec developed by the MIT Auto-ID Center. It is also responsible for the creation and management of a global computer network to store the database for assigned EPCs.
It should be noted though that, long before EPC was around, major RFID vendors were providing useful applications for RFID, including the EZPass toll system. And, ISO is working on its own set of standards as well. This is as technology that will have a tremendous future for many years to come.
Related News and Notes
The Chinese government has as interagency groupresponsible for drafting standards for RFID tracking technology. How will the outcome of their work influence standards in the RFID arena? Click here to find out more.
Visit one of our Sponsoring Companies (Click on a company name to visit their web site)
White papers are available fromour Sponsoring Companies and partners(Click on blue text belowto access a specific companies white paper)
Mobile RFID Advantages
R.W. Baird & Associates
Education: InsightU and The Center For Auto ID at Ohio University
Through a relationship with InsightU and The Center For Automatic Identification at Ohio University, SCAN/DCR is pleased to provide information that will help you define, design and use AIDC technology. Here you will finde-books, self-directedon line education and information about livetelephone conferences.