Radio-frequency identification (RFID) is an identification method similar in concept to bar code identification. It is also sometimes called dedicated short-range communication (DSRC).
The main component of RFID is the transponder (a receiver-transmitter), or RFID tag. It has an integrated circuit containing the radio-frequency circuitry and data to be transmitted, as well as an antenna. RFID tags can be used anywhere from clothing and food, to animals and humans. The tag can carry very simple information, like an owner's name, or complex information, like the process to assemble a car. It can be used not only for identification or security reasons, but also, for example, to guide computers on the next step in an automated assembly-line process.
Initially, RFID technology required line-of-sight (LOS) transmission, similar to bar codes. Later RFID technology that did not require LOS transmission became more popular. Non-LOS RFID can read information up ranges of 300 feet. The main current applications for RFID are:
- Car assembly lines
- Product tracing
- Human implants
- Libraries, schools and universities
- Animal identification
One difficulty using RFID is the possibility of collision when there is an overlap between the signals by two or more readers. In this case, the RFID tags would not respond correctly to these simultaneous requests. When setting up, be careful not to create much overlap between the range envelopes of the RFID tags.