Dynamically varying transmission rates of a traffic flow over respective portions of a primary band and a complementary band may allow a transmit point to satisfy quality of service (QoS) requirements over a unified air interface. The QoS requirement may stipulate that an overall transmission rate of the traffic flow over the unified air interface exceeds a threshold. Transmission rates may be varied based on a contention level of the complementary band. For instance, during periods of high contention, the transmission rate on the primary band may be ramped up to compensate for a lower effective transmission rate over the complementary band. Likewise, during periods of low contention, the transmission rate on the primary band may be stepped down to compensate for a higher effective transmission rate over the complementary band.