A Token-Based Scheduling Scheme for WLANs and Its Performance Analysis

Most of the existing WLAN MAC protocols can only provide limited service differentiation. In this paper, we propose a novel token-based scheduling scheme for precise and quantitative service differentiation, which can provide great flexibility and facility to the network service provider for service class management. Simulation results demonstrate that the proposed scheme can effectively achieve proportional differentiation among different classes, while achieving fair resource sharing within the same class. In addition, compared with the contention based scheme and the centralized polling scheme, the proposed scheme significantly improves the channel utilization by avoiding collisions (with the contention based scheme) and the polling overhead (with the polling scheme). The performance analysis of the proposed scheme is also presented. The accuracy of the analytical results are verified by computer simulations.