摘要

Dynamic bandwidth allocation (DBA) is of great importance and interest to multichannel passive optical networks (PONs). It plays a crucial role in efficiently and fairly allocating the bandwidth among all users. In this paper, a novel quota-based excess-distribution algorithm which can achieve accurate bandwidth allocation for end-users by using Computational Theory of Perceptions (CTP) has been proposed. To manage resources efficiently, we first present a mathematical model of bandwidth allocation based on matrix theory. Then, the quota-based excess-distribution algorithm is proposed and the excess distribution quota obtained from the algorithm is adjusted in real time and adaptively to further augment the efficiency and fairness of DBA. Thus, the excess distribution becomes more centralized and independent. The proposed algorithm can effectively prevent excess distribution from bandwidth monopolization and over-allocation. Besides, we formulate a wavelength assignment mechanism based on release time to eliminate the idle period and increase the bandwidth utilization of the network. Finally, we conduct detailed simulation experiments to research and analyze the performance in terms of delay, bandwidth utilization and fairness among ONUs. The simulation results demonstrate that at least 8.5% bandwidth utilization improvement and low average delay are achieved compared with other schemes and the fairness index keeps almost constant and is close to 1 in the proposed scheme.