Methods and devices for optimizing on-time throughput in a wireless network. An enhanced node B (eNodeB) integrating two or more air interfaces schedules transmissions, for a measurement period, over at least one of the two or more air interfaces. The eNodeB estimates, based on the transmissions, a metric of on-time throughput for the user equipment (UE) within the cell, where on-time throughput is a measure of an amount of data that arrives at a destination before a delay threshold has been reached and at a bit-rate greater than or equal to a target bit-rate. The eNodeB then assigns UEs within the cell to an air interface of the two or more air interface to maximize the metric of on-time throughput for the UEs within the cell.