Data is selectively transmitted over one or more carriers of a set of carriers. According to some aspects of the disclosure, a decision may be made to forgo the transmission of a preamble via one of the carriers (e.g., channels). For example, in a multi-carrier system, transmission of a preamble via one carrier may be inhibited if all of the data can be transmitted via another carrier. According to some aspects of the disclosure, a decision may be made to transmit different types of data on a single carrier rather than on multiple carriers. For example, a single carrier may be used to transmit schedule data and non-scheduled data if all of the data can be transmitted on one of the carriers (e.g., during a single transmission time interval). In this case, transmission of a preamble on another one of the carriers may therefore be inhibited.