A wireless communication system (20) includes backhaul congestion control. Whenever congestion is detected on the backhaul, a flow control message sets a window size to a reduced window size to reduce or eliminate packet drops and to facilitate alleviating the congestion condition. A disclosed example includes detecting backhaul congestion and responsively reducing an available backhaul receiver buffer space factor used for setting the window size for a subsequent backhaul transmission. In a disclosed example, the buffer space factor is gradually increased back toward an actual available buffer space as the congestion status improves.