868 MHz (UHF RFID) differs from other RFID technologies in that active tags are more commonly used. This is due to the system’s long range – up to 10–30 meters depending on the antenna and environment. At such distances, there isn’t enough energy to power the tag. Many UHF tags can still be run as “passive” devices at shorter distances.
UHF RFID is often used for larger objects that cannot be brought to a reader. For example, it can be used to identify vehicles for tolls and parking systems, keep track of locomotives on railways, for theft prevention, and for tracking objects that are moved around, such as hospital beds and other wheeled equipment.
