A system including a midamble detection module and a processing module. The midamble detection module is configured to detect a midamble of a packet transmitted via a channel, where the packet includes (i) a preamble, (ii) the midamble, and (iii) a plurality of data fields, where the preamble includes (i) a first short training field, (ii) a first long training field, and (iii) a signal field, where the midamble includes (i) a second short training field and (ii) a second long training field, and where the midamble follows the preamble and is between two or more of the data fields. The processing module is configured to determine that the channel is busy in response to detecting the midamble in the packet.