ltrahigh 433MHz and 25 ft. US$0.50 Even longer read Supply-chain (UHF) 868MHz-956MHz (8 m) ranges; high data tracking: boxes, throughput, which pallets, containers, facilitates higher trailers read rates Microwave 2.45GHz and 100 ft. US$25+ Very long range Highway toll collec- 5.8GHz (30 m) and access control tion, vehicle fleet applications identification WPANs LF and HF can be used globally without a license. UHF cannot be used glo- bally because there is no single global standard. Despite the availability of vari- ous bands in which RFID can operate, there is not just one that can address all applications. Each band has specific attributes that make it suitable for different applications. LF RFID The reading range of LF RFID can vary from a few centimeters to a couple meters, depending on the size of the tags and the reader being used. One of the key features of LF RFID is that it is not as affected by surrounding metals as other types of RFID, making it ideal for identifying metal items such as vehicles, equipment, tools, and metal containers. The largest user for LF RFID is the auto- motive industry. A car key has an LF tag embedded in it that works with a reader mounted in the ignition. Other automotive applications include vehicle identifica- tion for highway and parking lot access. LF RFID penetrates most other materials, such as water and body tissue, which makes it ideal for animal identification (for endangered species and for pets and livestock) and beer keg tracking. The limitations of LF RFID are that if used in industrial environments, electric motors may interfere with the LF system. Due to the size of the antenna required, LF tags are typically more expensive than HF tags, which limits LF to applications where the tags can be reused. However, LF is used worldwide, and there are no restrictions on its use. HF RFID Passive HF, at 13.56MHz, is a globally accepted frequency, which means any system operating at HF can be used globally. However, there are some differences between the regulations in the