The RFID system is pretty simple. It has 4 main components: the tag, the antennae, the reader, and the host PC or computer. Each RFID tag comes with an antenna. When a truck or container bearing an RFID tag enters the port entry and exit gates, a tag reader picks up information and shares it with the host PC.
There are various types of RFID systems. For instance, low-frequency RFID systems have a very short range. High-frequency systems also have a range of up to around 5 inches. Meanwhile, the UHF or ultrahigh-frequency RFID operates in a larger area. This is the system most for container tracking.