Adaptive multimedia is promising in wireless/mobile networks since it mitigates the fluctuation of resources caused by mobility in these networks. However, bandwidth adaptation entails the bandwidth degradation for some applications. In order to effectively characterize the bandwidth degradation and to provide better quality of service (QoS) to users, we propose two new QoS parameters for adaptive multimedia: the degradation ratio (DR) and the degradation degree (DD), which characterize the frequency of bandwidth degradation and the degree of bandwidth degradation, respectively. Based on DD and DR, a measurement-based call admission control framework and a K-level bandwidth adaptation algorithm are proposed to satisfy the application QoS requirements in terms of the proposed parameters, and to utilize the network resources efficiently. Simulations reveal that DD and DR outperform other QoS parameters in terms of effectively characterizing bandwidth adaptation. Simulations also indicate that the adaptive multimedia framework outperforms the non-adaptive multimedia services. © 2002 Elsevier Science B.V. All rights reserved.