A method of transmitting at least one broadcast signal frame having physical layer pipe data, PLP, and preamble data, in which the procedure comprises: mapping the bits of the PLP data into PLP data symbols and preamble data bits in the preamble data symbols; build at least one data segment based on the PLP data symbols, in which the data segment is one of a first type of data segment and a second type of data segment, in which the first type of data segment does not have a frame header and the second type of data segment has the frame header, in which the frame header includes modulation and coding parameters of the PLP data; construct a signal frame based on preamble data symbols and data segments; and modulating the signal frame by an orthogonal frequency division multiplexing procedure, OFDM, in which the preamble data symbols include the L1 signaling information Layer 1, in which the L1 signaling information is interlaced in time to an interlocking block in time TI L1 within a block L1 according to an interlocking depth in time, and a header L1 is included in the front of the TI block L1, and the header L1 and the block TI L1 are repeated in frequency within one of one of the preamble data symbols, in which the L1 signaling information includes data segment ID information that identifies a data segment, and in which the time interlaced depth is signaled in signaling information L1.