In the embodiments of the present disclosure, the indication information may be transmitted through the data symbol, i.e., the access device may determine the quantity of the PSP-IDs in accordance with the information carried in the data symbol.

In some possible embodiments of the present disclosure, the indication information may be carried in the QPSK symbol of the data symbols in the PRACH, i.e., the indication information may be transmitted through the QPSK symbol of the data symbols. For example, when the PRACH contains the data symbols (D), the corresponding indication information may be carried in the QPSK symbol corresponding to each data symbol D. To be specific, the indication information may be encoded, and the encoded indication information and a Cyclic Redundancy Code (CRC) may be mapped to the QPSK symbols of one or more data symbols in a same interlacing unit for transmission. In addition, for the data symbols D in the PRACH, different formats correspond to the data symbols in different quantities. For example, when the B-IFDMA symbols PPDD in the PRACH are merely orthogonal to each other in the frequency domain through CS as indicated by a left part of FIG. 6, two QPSK symbols may be carried in a bandwidth of one PRB. When a system bandwidth is 20 MHz, one interlacing unit may include 10 PRBs for transmitting 40 bits, so as to carry the indication information and the CRC in the 40 bits. For another example, when the B-IFDMA symbols PP in the PRACH are orthogonal to each other through the OCC and the B-IFDMA symbols DD are orthogonal to each other through the OCC as indicated by a right part of FIG. 6, one QPSK symbol may be carried in a bandwidth of one PRB. When the system bandwidth is 20 MHz, one interlacing unit may include 10 PRBs, so it is able carry the indication information and the CRC in 20 bits.