A reusable casket includes a metal casket box having an opening at one end and includes a panel section rotatably attached to the casket box which is closeable to enclose the opening and openable to allow longitudinal movement of a casket insert into and out of the casket box through the opening. It is prepared as follows: in the pyrogenic preparation of titanium dioxide, a metal salt solution is atomised to form an aerosol and injected into the production stream. A unique reply number is allocated and recorded in a pending reply list. The estimator estimates an OLA length in a current OFDM symbol of an OFDM signal according to a channel property.