Modeling QoS degradation in multimedia wireless networks

We propose call degradation and admission strategies based on modeling quality-of-service (QoS) degradation of multirate traffic for third generation multimedia wireless network. The real-time traffic is classified into K classes based on the bandwidth requirements, where a class i call uses i channels. To increase the carried traffic in an overloaded system, some of the ongoing calls release channels that they are using and enter a degraded mode of operation. Two orthogonal QoS parameters called carried traffic and bandwidth degradation are defined, and a cost function describing the total revenue earned by the system from a bandwidth degradation policy is formulated. This cost function model is extended to incorporate a call admission policy, and methods are shown to compute the optimal call admission and degradation policies which maximize the effective revenue earned. Detailed simulation experiments are conducted to validate our proposed model.