Recent advances on wireless technology are enabling the design and deployment of multiservice wireless networks. In order to be able to meet the QoS requirements of the various applications, it is essential to deploy QoS provisioning mechanisms. To be most effective, these mechanisms require to monitor the status of the various active sources enabling them to better distribute the available resources. In this paper, we propose a QoS provisioning mechanism for time constrained applications. Our simulation results show the effectiveness of the proposed mechanism when supporting time constrained services, such as MPEG-4 video communications.