Abstract: Adaptive QoS service in mobile network can improve the system capacity by decreasing its source rate when the network is busy. This merit is especially important when broadband services are provided. A new parameter P_D is defined to approximately describe the QoS of adaptive service, and the cell capacity with adaptive service is analyzed using a M/M/m(m) queuing model. The trade-off relationship between the QoS of adaptive serviceand call block ratio, system capacity, system efficiency is illustrated. The numeric result shows that using adaptive QoS service, the capacity and efficiencycan be effectively improved and the call block ratio can be largely reduced.Key words mobile communication networks; quality of service; adaptive QoS service

Key words: mobile communication networks, quality of service, adaptive QoS service