QPID-AVQ：一种基于队列的PID控制的AVQ算法

本文针对AVQ算法存在的不足,在PD-AVQ算法基础上,为进一步提高系统的稳定性,引入积分选项,构成PID-AVQ算法,运用控制理论推导出了满足系统稳定条件的取值范围.利用PID-AVQ算法更新虚拟带宽,综合考虑平均队列长度和包到达速率,提出了一种新的基于队列的PID控制自适应虚拟队列管理算法QPID-AVQ,可根据网络实际情况调节参数,保持队列长度稳定.仿真结果表明,当控制参数在稳定范围内取值时,QPID-AVQ算法能较好地适应网络状态变化,使队列长度始终维持在期望值附近,而不受用户数量的影响,具有较好的稳定性、抗干扰能力和较高的带宽利用率,综合性能优于PD-AVQ和RED算法.

QPID-AVQ:A Novel PID-Controlled Adaptive Virtual Queue Algorithm Based on Queue Length

To settle the problems existing in AVQ algorithm and to further improve the performance of system stability and anti-jamming, a novel adaptive virtual queue algorithm is proposed, termed PID-AVQ, which added integral control function to PD-AVQ algorithm. Furthermore, considering both queue length and packet arriving rate, a novel PID-controlled adaptive virtual queue algorithm is proposed based on queue length, termed QPID-AVQ. QPID-AVQ algorithm sets parameters in terms of the real network statuses, which levels off the queue length at approximate expected value. And QPID-AVQ algorithm adopts the PID-AVQ algorithm to update the virtual capacity. The simulation results show that, QPID-AVQ algorithm can adapt to changes in network conditions well, and can keep queue length at approximate expected value while not being affected by the number of FTP connections. And compared with PD-AVQ and RED algorithms, QPID-AVQ algorithm has better stability, anti-jamming capability and higher link utilization.