Optical Data Transmission Scheme Considering QoS in IP over WDM Networks

互联网业务的爆炸式增长推动了对波分复用（WDM）网络中新的高速传输和交换技术的需求。同时，各种多媒体业务的需求也在不断增长，如何保证WDM层的服务质量（QoS）是一个具有挑战性的问题。在本研究中，首先提出了一种新的WDM城域环网变长分组MAC方案。在该方案中，一个节点发送一个短的数据包的基础上非时隙IP回退方案。并且当节点发送长分组时，该节点预先向其他节点发送用于预留的子载波信号，并且可以在子载波信号返回到该节点之后发送长分组。计算机仿真结果表明，该方案可以提高分组平均时延性能和吞吐量性能。其次，提出了一种基于突发丢弃（BD）技术的光突发交换（OBS）网络QoS控制方案 ...更多信息 罗普斯。该方案由BD技术和分组排列技术组成。通过计算机模拟，它已被证明，该方案可以提供QoS区分的分组丢失，而不会降低延迟性能。第三，为了在光复合突发交换（OCBS）网络中实现与跳数无关的公平分组丢失概率，已经提出了一种新的突发丢弃技术，其基于跳数改变应用头丢弃技术的概率。计算机仿真结果表明，与传统的分组丢失算法相比，该算法无论跳数多少都能获得公平的分组丢失概率。第四，提出了一种新的QoS方案，该方案考虑了分组丢失概率和分组延迟的QoS要求。该方案将业务分为四类，并根据业务的类别自适应地结合了突发长度控制、偏移时间控制和BD技术三种控制技术。通过计算机模拟，表明该方案可以提供四个类之间的QoS区分。最后，为了减少时间分片OBS网络中未使用的时隙，提出了一种新的调度算法，该算法考虑了通过分配数据突发而新产生的头间隙和尾间隙。仿真结果表明，与传统的调度算法相比，该调度算法可以提高突发丢失率和吞吐量。少

The explosive growth of Internet traffic is driving the demands for new high-speed transmission and switching technologies in Wavelength Division Multiplexing(WDM) network. Also, the demands in various multimedia services are increasing and it is the challenging issue how to guarantee Quality of Service(QoS) in WDM layer. In this research, at first, a new MAC scheme for variable length packet in WDM metro ring network has been proposed. In the proposed scheme, a node transmits a short packet based on Unslotted IP with Backoff scheme. And when a node transmits a long packet, the node transmits a subcarrier signal for reservation to other nodes beforehand and can transmit a long packet after the subcarrier signal returns to the node. By computer simulations, it is shown that the proposed scheme can improve the mean packet delay performance and throughput performance. Secondly, a new QoS control scheme by using Burst Dropping(BD) technique in Optical Burst Switched(OBS) network has been p … More roposed. The proposed scheme consists of BD technique and the packet arrangement technique. By computer simulations, it has been shown that the proposed scheme can provide QoS differentiation in terms of the packet loss without degrading the delay performance. Third, in order to achieve the fair packet loss probability regardless of the number of hops in Optical Composite Burst Switching(OCBS) network, a new burst dropping technique has been proposed that changes the probability of applying the Head-Dropping technique based on the number of hops. By the computer simulation, it is shown the proposed scheme can achieve the fair packet loss probability regardless of the number of hops compared with the conventional one. Fourth, a new QoS scheme has been proposed that takes the QoS requirement for both the packet loss probability and the packet delay into account. The proposed scheme divides traffic into four classes and combines three control techniques, the burst length control technique, the offset time control technique and BD technique according to classes adaptively. By computer simulations, it is shown that the proposed scheme can provide QoS differentiation between four classes. Finally, to reduce unused timeslots in Time Sliced OBS network, a new scheduling algorithm has been proposed that considers head gap and tail gap newly generated by assigning a data burst. By computer simulations, it is shown that the proposed scheduling algorithm can improve the burst loss probability and the throughput compared with the conventional one. Less