Abstract: A method and apparatus for transmitting and receiving data via guard tones are described. The information bits are coded by convolutional encoder (101) and some of the punctured bits from punctured (102) are selected with bit selector (105) and subject as the punctured data to interleaving by an interleaver (106-103 for the punctured data-). The OFDM process that follows (104, 107, 108) maps the interleaved selected punctured bits to guard tones and the interleved punctured data to data sub-carriers.

Abstract: In a temperature-recording method for recording a temperature by means of an electrical circuit of a data storage medium, which electrical circuit is suppliable with energy by means of a signal feedable to the data storage medium, provision is made for a physical variable dependent on the temperature to be recorded by means of the circuit supplied with energy, the physical variable being influenced by a temperature-recording material (1, 7), preferably a piezoelectric or ferroelectric material, co-operating with the circuit, which material comprises alignable electric or magnetic elementary dipoles (3), and for which temperature-recording material (1, 7) a Curie temperature is known, exceeding of which causes the alignment of the elementary dipoles to be lost, and the temperature-recording material (1, 7) being selected in such a way that its known Curie temperature corresponds to a pre-determined limit temperature.

Abstract: An optical information record medium (1) has at least one information layer (100) comprising a transparent substrate wherein nano-elements (101), for example nanotubes, having a symmetry axis are embedded. Information can be recorded by orienting the axes of the nano-elements within selected regions (110,120) in the same direction. Information can be read from the medium by means of a radiation beam having a polarization direction (p1, p2) corresponding to the said direction of the nano-elements, thereby creating absorptive information areas (110,120). In this way high information density can be achieved.