Methods and apparatus for transmitting data having a data stream in a wireless broadcast system are provided. The data stream is mapped onto a super-frame having frames. Each frame includes a preamble section and a data section. The data section carries the data stream, and the preamble section carries signalling information. The data section of each frame is segmented into frequency zones. At least part of the data stream is mapped to a first frequency zone. A signalling information word is generated that carries signalling relating to a position and a bandwidth of at least the first frequency zone. The signalling information word is included in the preamble section of a given frame. The preamble section is transmitted within a first frequency bandwidth and the first frequency zone is transmitted within a second frequency bandwidth. The first frequency bandwidth is greater than the second frequency bandwidth.