A low-alloy steel containing, by weight percent, C 0. The isochronous back channel provides retransmission and flow control information from the receiving device to the transmitting device related to a stream of isochronous data packets transmitted from the transmitting device to the receiving device. The signal processing section 151 performs Fourier transform when the wireless terminal is compatible with the OFCDM system; the signal processing section 151 performs Fourier transform and inverse Fourier transform compatible with an OFDM system when the wireless terminal is compatible with the OFDM system and a CDMA system. The defect replacement allowance attribute data indicates whether recording of the user data has been executed in a state that the execution of a defect replacement process is allowed. Therefore, it is to be understood that it should not be used to interpret or limit the scope or the meaning of the claims.