OBS网络中基于改进波长分组技术的QoS策略  

QoS algorithm based on improved wavelength grouping in optical burst switching networks

作　　者：刘春玲[1] 张兴周[1] 吕博[1] 

机构地区：[1]哈尔滨工程大学信息与通信工程学院,黑龙江哈尔滨150001

出　　处：《应用科技》2011年第2期32-37,共6页Applied Science and Technology

摘　　要：在光突发交换(optical burst switching,OBS)网络中如何支持服务质量(quality of service,QoS)是一个很重要的问题,为了能在对高优先级业务提供足够保障的同时,尽量减小低优先级业务的丢包率,提出一种能有效支持QoS的新方案.该方案在改进的波长分组预留策略(improved wavelength grouping,IWG)基础上结合使用了最适合空隙填充算法(best fit-void filling,BF-VF)和光纤延迟线(fiber delay line,FDL)技术,可以根据各个优先级业务丢包率的变化情况,动态地调整各个优先级业务使用的波长数目,并且通过计算信道利用因子将数据突发调度到合适的信道Viod上,同时为调度失败的突发包提供了二次调度的机会.仿真结果表明,该算法可以在不同的网络状态下有效提高信道的利用率,降低整体丢包率,并能很好地支持QoS.QoS（quality of service） supporting is an important issue in OBS（optical burst switching） networks.In order to provide sufficient guarantee for high-priority traffic and minimize the burst loss ratio of lower priority traffic,a new approach for supporting QoS in OBS networks is proposed.It consists of the improved wavelength grouping（IWG） scheme,fiber delay line（FDL） technique and the best fit-void filling（BF-VF） scheduling algorithm.In this approach,the number of wavelengths used in each class is adjusted dynamically,according to the variation of its burst loss ratio.Through calculating the void utilization factor,this approach schedules the new data burst into an appropriate channel void and at the same time provides second schedule opportunity for those bursts which are not scheduled successfully.The results of simulation show that the algorithm can support better QoS,decrease the burst loss probability and improve the channel utilization in different network statuses.

关 键 词：光突发交换(OBS) 服务质量(QoS) 波长分组 信道调度 光纤延迟线 

分 类 号：TN929.11[电子电信—通信与信息系统]