RFID - HF Technologie
High-frequency systems (HF-RFID) are used for applications in which large reading distances have to be covered. They are operated with a frequency of 13.56 MHz. Examples include tracking library inventory or identifying patients in a hospital. Another common application is logging maintenance work on important devices that have to be inspected regularly. High-frequency tags enable faster information transmission. They bridge large distances, but are also more expensive than low-frequency tags.
RFID - UHF Technologie
As a result of larger reading distances and lower unit costs expected in the future, the current trend is headed toward ultra high frequency tags, or UHF tags. This frequency is recommended for sales and logistics applications and currently forms the basis of the EPC standard (Electronic Product Code). The EPC Standard is the focal point of Wal-Mart and Metro. It involves an expanded numeration formula that was specially developed for RFID use.