A system and method for multiplexing traffic. A wireless device such as a user equipment (UE) may receive a first signal over first resources assigned to carry a first downlink transmission from a base station, and receive a first downlink control indication (DCI) message from the base station. The first DCI message may include a pre-emption region (PR) indication and a PR bitmap, and the PR indication may indicate a location of a time-frequency region. The PR bitmap may include bits associated with different portions of the time-frequency region, and each of the bits in the PR bitmap may indicate whether a preemptive downlink transmission is present in the corresponding portion of the time-frequency region.