This paper addresses the problem of supporting soft real-time traffic over IEEE 802.11 wireless local area networks in the presence of competing non-real-time traffic. The proposed solution is a wireless traffic smoother (WTS) which uses as inputs the throughput and the number of frame retransmissions at the MAC level. Combining these two inputs, the WTS is able to adapt the smoothing action to the current wireless network condition. The paper discusses the WTS, also highlighting the way it advances the current state of the art. Then, the WTS performance obtained from experiments performed on a real testbed, also in comparison to another approach recently proposed in the literature, is discussed.