A data transmission method, a wireless network device, and a communications system are provided. The method includes: sending, by a first wireless network device, at least two channels for common information on a same carrier, where the at least two channels for common information include a first channel for common information and a second channel for common information, the first channel for common information and the second channel for common information are on different subbands of the same carrier, and the common information includes at least one of a synchronization signal, a broadcast signal, or a system message.