What are RFID systems?

RFID refers to procedures for the automatic identification of objects via radio. The use of RFID systems is suitable in principle wherever automatic marking, recognition, registration, storage, monitoring or transport is required.
RFID systems come in many variations. Although there are a wide range of RFID solutions, each RFID system is defined by the following three characteristics:

1. Electronic identification:
   The system allows unambiguous identification of objects through electronically saved data.
2. Contactless data transfer:
   The data can be read wirelessly via a radio frequency channel to identify the object.
3. On call:

A tagged object only sends its data when a designated reader calls up this process.
From a technological point of view, an RFID system consists of two components -- a transponder and a reader:

• The transponder -- also known as a "tag" -- functions as the actual storage medium. It is attached to an object (e.g. goods or packaging) or integrated into an object (e.g. a chip card) and can be read contactlessly via radio technology and potentially also written to again, depending on the technology. Basically, the transponder consists of an integrated circuit and a radio frequency module. An identification number and further data about the transponder itself or the object to which it is connected are stored on the transponder.
• Depending on the technology used, the recording device -- typically referred to here as a reader -- consists of a reading or read/write unit and an antenna. The reader reads data from the transponder and, if necessary, instructs the transponder to store further data. The reader also controls the quality of the data transmission. The readers are typically equipped with an additional interface to forward the received data to another system (PC, vending machine control, ...) for further processing.

RFID systems use different frequency ranges in the long-wave to the microwave range. Another distinctive feature of RFID systems is the storage technology used. A basic distinction is made here between read-only and read-write systems.

The type of energy supply to the transponder and the resulting distinction between active transponders with their own energy source and passive transponders that are supplied with energy by the reader is also of fundamental importance. On the basis of these characteristics, groups of RFID systems can be formed and differentiated in terms of the performance of their respective components into low-end systems, systems of medium performance and high-end systems.

A further grouping of RFID systems can be made according to their respective range -- i.e. the maximum possible distance between transponder and reader.

As a rule, a distinction is made here between close-coupling, remote-coupling and long-range systems.

Transponder designs range from glass injectables and electric ear tags to credit card formats, different disc designs and storage media that are impact-resistant and heat-resistant up to 200° Celsius for paint lines for the automotive industry. The flexible design of the identification points, size, shape and field characteristics of the antenna make RFID systems as a whole a highly versatile automatic identification technology. These groupings allow both a classification of RFID systems in terms of the potential applications based on them and an assessment of the associated issues of information security and data protection.