This paper presents a congestion control protocol for ad-hoc Wireless-LAN ( WLAN) with Bandwidth-on Demand (BoD) access. The novelty of this paper is in the extensive use of model-based control methodologies to simultaneously compute the capacity requests necessary to access the network ( BoD) and the capacity allocations required to regulate the rates of the traffic flows ( congestion control). The proposed scheme allows one to compute upper-bounds of the queue lengths in all the network buffers ( thus allowing proper buffer dimensioning and, therefore, overflow prevention), avoids that the assigned capacity is left unused ( thus entailing full link utilization) and guarantees the recovery of a satisfactory traffic behaviour as soon as congestion situations terminate ( congestion recovery). The high-speed WLAN considered in the paper has been developed within the European Union ( EU) project Wireless Indoor Flexible High Bitrate Modern Architecture ( WINDFLEX). Extensive simulations prove the effectiveness of the proposed scheme.