摘要
VOD 系统中,有限的磁盘 I/O 带宽或缓存空间往往成为系统的瓶颈。针对这一问题,提出了自相似业务下视频服务器的接纳控制算法。该算法运用等效带宽理论,通过在线测量系统所剩资源和周期容限的幅度变化来实时调节调度周期的大小,使得系统所剩资源达到动态的“等量”平衡。仿真结果表明,该算法不但简化了接纳过程,节约了系统资源,提高了算法的可实现性,而且系统的接纳率比 Lee,Yeom 所提算法的接纳率提高了 15%,并且还可根据系统的 QoS 参数灵活调整接纳率。
In VOD systems, the limited disk I/O bandwidth and buffer space frequently causes system bottleneck, therefore, an admission control algorithm about self-similar video traffic is proposed. Based on effective bandwidth theory, the length of scheduling period is on-line adjusted according to current residual system resources and variable range of period tolerance. As a result, residual system resources are in a dynamic ‘equal quantity’ balance. The simulation results show the proposed algorithm has a simplified admission process, low resource consumption and better realizability. The admission rate of the system increases by 15% compared with that of the algorithm proposed by Lee and Yeom, while keeping a flexible adjustment between desired QoS and admission rate.
出处
《通信学报》
EI
CSCD
北大核心
2004年第10期148-154,共7页
Journal on Communications
关键词
接纳控制
自相似
动态调度周期
等效带宽
admission control
self-similar
dynamic scheduling period
effective bandwidth
