Adaptive Radio Resource Allocation in Hierarchical QoS Scheduling for IEEE 802.16 Systems

Future mobile communication systems such as IEEE 802.16 are expected to deliver a variety of multimedia services with diverse QoS requirements. To guarantee the QoS provision, appropriate scheduler architecture and scheduling algorithms have to be carefully designed. In this paper, we propose an adaptive bandwidth distribution algorithm for the aggregate scheduler in a two-level hierarchical scheduler, which can provide more organized service differentiation among different service classes. By taking the backlogged traffic, the spectral efficiency in terms of modulation efficiency, and the QoS satisfaction into account, the proposed algorithm adaptively allocates bandwidth to each service class with the objective of increasing the spectral efficiency while satisfying the QoS requirements. Through system-level simulation, it is shown that the proposed algorithm can adapt to the performance of the class schedulers and distribute the bandwidth among them more efficiently than the conventional schemes.