Such a system is known per se. The current systems used for walk-through, walk-along or walk-over recognition comprise a large transmitting antenna which ensures the activation of the labels and which is also used for the reception of the return signal. Here, an absorption system is involved. The labels used in these systems are relatively large while the orientation of the labels is controllable. So-called management labels can for instance be considered in the form of an ear stud or labels attached to the neck of an animal.
Regarding the international legislation, more and more so-called I&R labels find use in walk-through recognitions. These so-called I&R labels are small electronic earmarks and/or electronic boluses. What is also considered is the use of smaller labels that are implanted subcutaneously. The characteristic of such labels is that due to their smaller size, they often produce a smaller return signal than the above-mentioned labels. Another problem is that interference of the reception of the return signal from these labels can occur due to the presence of, for instance, fluorescent lamps with electronic ballasts, frequency controls for electric motors, transmitters that emit in the same frequency range, etc. When a plurality of labels are simultaneously present in the detection zone and is activated, the return signals from these labels will furthermore interfere with each other.