RFID tags are classified by frequencies. RFID tags, antennas and readers are tuned just like a radio is tuned to a specific frequency to receive different stations. RFID has different flavors of a similar technology. For example, low frequency RFID and high frequency RFID tags can be used globally without a license.
Different vertical markets require different RFID tags as each frequency range has its advantages and disadvantages. Low Frequency RFID tags (LF) are less costly to manufacturer than Ultra High Frequency (UHF) RFID tags. UHF RFID tags offer better read/write range and can transfer data faster then other RFID tags. HF RIFD tags work best at close range and are highly effective at penetrating non-metal objects especially objects with high water content.
Attention recently has been focused on the supply chain. The initiatives driven by WalMart and the DoD have created a new level of RFID awareness. These initiatives have also accelerated the creation of new RFID GEN 2 standards. GEN 2 is beginning to unseat some legacy RFID practices.
There are complicating factors that have somewhat hindered faster progress in the UHF RFID market. As mentioned above, UHF technology suffers from lack of standards and regulations. ISO and EPC Global are the main bodies that work to draw standards and specifications for UHF RFID. However, at times, these two organizations seem to be moving in competing paths, resulting in duplication of efforts and confusion in the market place. This has caused some major vendors and users to delay their entry into the RFID market. At present, EPC standards have defined specification for Class 0, Class 1, and GEN2 tags. At the same time, 18000-6 is the ISO standard for the 900 MHz UHF band. UHF or GEN2 has been tapped as the go ahead technology for the supply chain. GEN2 is also beginning to erode legacy LF and UHF laundry tag solutions as GEN2 price decreases and capability such as greater read distances increases.
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