光突发交换与下一代互联网

光突发交换是交换粒度介于光电路交换(即波长交换)和光分组交换之间的一种光交换模式,因为它克服了光电路交换和充分组交换的缺点,具有很大的技术优势,很有可能成为下一代互联网骨干网络的核心技术,真正实现光子互联网。本文介绍光突发交换技术的基本原理,讨论了光突发交换的协议、突发封装和在IP骨干网中的应用等问题,并指出在这项技术得到应用之前需要解决的诸多课题。     

光突发交换与下一代互联网

光突发交换与交换粒度介于光电路交换（即波长交换）和光分组交换之间的一种光交换模式，因为它克服了光电路交换和光分组交换的缺点，具有很大的技术优势，很有可能成为下一代互联网骨干网络的核心技术，真正实现光子互联网。本介绍光突发交换技术的基本原理，讨论了光突发交换的协议，突发封装和在IP骨干网中的应用等问题，并指出在这项技术得到应用之前需要解决的诸多课题。     

光突发交换中的突发包组装技术研究

光突发交换是近几年出现的一种很有前途的光交换技术，比电路交换灵活，带宽利用率高，又比光分组交换易于实现，突发包的组装是光突发交换的关键技术，在很大程度上影响到光突发交换网络的性能。文中介绍了光突发包的格式，描述了交换网络中突发包组装所需的层次结构和功能结构，并给出了一种典型的生成算法。最后，对选择突发包组装时间应考虑的各种因素进行了系统的分析。     

基于JET协议的OBS网络关键技术研究

光突发交换(OBs)技术比电路交换具有更高的带宽利用率、更低的网络延时,而且比全光分组网更加易于实现,文章针对基于JET资源预留协议的光突发交换网络,在突发汇聚、QoS保证、控制分组和数据分组的具体内容等关键技术上进行了较详细的讨论和研究．     

光突发数据包整合技术的研究

光突发交换是适合在当前技术条件下的新交换技术，它比电路交换灵活，带宽利用率高，又比光分组交换易于实现，将成为下一代光IP骨干网的核心技术。介绍了控制分组结构。重点研究了光突发交换的关键技术—突发数据包整合技术的各种方法，指出突发数据包整合技术在很大程度上影响着光突发交换网的性能。     

OBS网突发包竞争问题的解决方案

光突发交换(OBS)是近几年出现的一种很有前途的新型光交换技术。由突发包之问竞争所导致的数据丢失是光突发交换网络所面临的一个重要问题，它影响到光突发交换能否走向实用化。为此提出了一种用于解决突发包之间竞争钧综合方案，并对它的性能进行了仿真研究。仿真结果表明，该方案可以大幅度地降低OBS网络中的数据丢失事。     

利用GMPLS实现光突发交换

DWDM技术虽然可以实现较大的传输容量，但是在对信息进行处理的过程中，却存在着电子瓶颈，传统网络仍然需要在交换节点处对数据进行电的交换处理，从而降低了网络的交换处理速度。为了实现在光网络上直接传送数据业务，人们提出三种IP over DWDM网络方案：波长路由交换光网络、突发交换光网络和分组交换光网络。     

未来光网络中的LOBS技术

光突发交换技术和MPLS的迅速发展产生了一种更加灵活、紧凑的IP／DWDM集成方案LOBS。它综合了光路交换和光分组交换的优点及最先进的MPLS的强大控制能力，是下一代因特网的理想光交换方案，并且为光分组交换的实现奠定了基础。文中在全面介绍LOBS交换网络结构和控制协议的基础上，分析了LOBS流量工程和QoS机制，最后初步讨论了LOBS时延和阻塞率特性。     

光标签突发包交换技术

光标签突发包交换是一种新出现的光交换技术。它把基于标签转发的速度优势、QoS(服务质量)保证及流量工程与光突发包交换控制机制(更长的转发数据单元、光网络边缘缓存、带外信令控制)结合起来。全面介绍了这种光交换技术，重点描述了其网络结构。另外，还对其所涉及到的关键技术进行了讨论，并结合下一代互联网的技术趋势，对光标签突发包交换的前景进行了评价。     

基于光标签的光分组交换系统研究

光码分复用(OCDM)系统在光域对各路信号进行光编/解码,对用户数据进行全光信号处理,但是用户数目受到光标签数量的限制.光分组交换技术具有高速率、对数据速率和格式透明等优点,更能适应快速变化的网络环境,但存在光标签的提取、更新和竞争的难题.介绍了一种新型的基于WDM(波分复用)和OCDM的光分组交换系统,结合了光码分多址(OCDMA)技术和光分组交换(OPS)技术的优点,既扩展了系统用户容量又避免了对标签进行电域的处理,实现了数据的全光交换.     

光突发交换网络中的突发分组组装策略

光突发交换(OBS)技术集成光电路交换和光分组交换的优势,能满足现有大容量、高速率的多媒体信息交换与传输,将成为下一代光IP骨干网的核心技术。本文详细论述了OBS网络中的关键技术———突发分组的组装技术的各种策略与实现方式,指出具有良好QoS保证又可降低可操控性的突发组装策略将成为最佳选择。     

光突发交换技术

光突发换是近几年出现的一种光交换技术 ,它交换的单元粒度介于电路交换和分组交换之间 ,比电路交换灵活 ,带宽利用率高 ,又比光分组交换易于实现 ;全面介绍了这种交换技术 ,并对它与电路交换和光分组交换性能进行了比较。另外 ,还对光突发交换的关键技术进行了讨论 ,结合下一代互联网的技术趋势 ,对光突发交换的前景进行了评价。     

Congestion-Controlled Optical Burst Switching Network With Connection Guarantee: Design and Demonstration

A congestion-controlled optical burst switching network that offers connection guarantees was designed to handle bursts as short as 100 ms with switching within 10 ms in networks less than 200 km long. Its optical burst switching (OBS) is based on circuit switching, and transport is by optical burst paths. Five metrics are proposed for evaluating OBS network performance. The application area to be laid and the data application were determined in accordance with the design target. Given a reasonable burst block probability requirement, design criteria are developed on the basis of wavelength switching and conversion implementation. OBS network performance is tested in field trials on the Japan Gigabit Network II testbed. Fast congestion control through the use of precalculated detour routes is demonstrated.      

The study of QoS guarantee in the optical burst switching internet backbone

Optical switching technology can be categorized into optical circuit switching (OCS), optical packet switching (OPS) and optical burst switching (OBS). OCS is suitable for large amounts of data transmission; however, the channel utilization is inefficient when the traffic flows are intermittent. OPS can be easily adapted to any higher layer and is suitable for bursty traffic, but it requires a highly complex technology and optical buffer. The new switching paradigm, OBS, can provide higher bandwidth utilization and meanwhile avoid the complexity in OPS technology.In this paper, we investigate how the quality of service (QoS) can be guaranteed and reliable transmission can be supported in the OBS-based Internet backbone. We propose the adjustable-time-counter-based (ATCB) burst assembly and the non-real time packet retransmission mechanisms and apply them in the ingress router of the OBS Internet backbone to guarantee the quality of real time applications and lossless requirement of non-real time services. Moreover, traffic shaped is performed for real time packets in the egress router so that the real time property is preserved with a low jitter. Simulation results show that the burst blocking probability using the ATCB burst assembly is improved, compared with the time-counter-based (TCB) and burst-length-threshold-based (BLTB) mechanisms. The delay, loss and jitter of real time service conform to the QoS requirement. Meanwhile, the delay of non-real time service also falls in the acceptable range.     

光通信网对数据信息的Burst交换

说明通信网交换方式从电路交换至分组交换和Burst交换的演变以适应全光通信网的发展趋势。解释了通信网利用Burst交换所需的网络边缘设备和核心结点设备。     

Impairment-aware ordered scheduling in dual-header optical burst switched networks

Optical burst switching (OBS) is a promising technology for bridging the gap between optical wavelength switching and optical packet switching. Optical signal transmission quality is subject to various types of physical impairment introduced by optical fibers, switching elements, or other network components. The signal degradation due to physical impairment may be significant enough such that the bit-error rate of received signals is unacceptably high at the destination, rendering the signal to not usable. In this article, based on earlier study, we study the burst-scheduling problem in OBS networks using two control packets for each data burst, taking into account physical impairment effects. We propose a burst-scheduling algorithm that accommodates incoming bursts by primary path routing, deflection routing, and burst scheduling. We design an admission control mechanism to use network resources efficiently. At an OBS node, the proposed algorithm schedules bursts for transmission by searching for available resources as well as verifying signal quality. Our simulation results demonstrate that the proposed algorithm is effective in terms of reducing the burst-blocking probability.     

光突发包交换网络中的偏置时间管理

光突发包交换是近几年出现的一种新的光交换技术,其本质是利用控制分组来预留突发包所要经过的各节点处的带宽。因此,必须要求突发包和控制分组在传送过程中保持两者之间合理的时序关系。这就是偏置时间的配置问题。首先介绍了一种典型的OBS协议-JET协议的原理,然后提出获得基本偏置时间的方案(包括无连接和面向连接两种方式)和偏置时间随机化的改进方案,最后讨论了JET协议在实施过程中可能出现的问题。     

Node dimensioning in optical burst switching networks

Network dimensioning should be progressed for pursuing the ultimate efficiency of network system resources in order to satisfy target performance. This article studies node dimensioning as a method of resource optimization in optical burst switching (OBS) networks. OBS is a new switching technology for pursuing bufferless transparent optical networks by sending control packets prior to data burst in order to provision resources for the burst. However, the basic assumption of a bufferless node implies burst contention at a core node when more than two bursts attempt to move forward the same output simultaneously. Thus, burst contention is a critical performance metric and this article takes it into account as a constraint on node dimensioning and target performance. In this article, we first present node dimensioning issues for OBS networks. Two constraints from the transport plane and the control plane which affect burst contention are then introduced. The effect of the burst assembly process on node dimensioning is also presented. From numerical analysis, the optimal number of wavelengths in a link, which provides the lowest blocking probability, is obtained to suggest a guideline for node dimensioning.     

光突发交换中的路由技术

光突发交换是面向下一代因特网的光交换模式,是光电路交换和光分组交换的有效折衷方案,避免了各自的缺点.它使用的带宽粒度介于光电路交换和光分组交换之间,比光电路交换灵活,带宽利用率高,比光分组交换易于实现,是很有发展前途的光交换技术.路由技术在光突发交换中起重要作用,在很大程度上影响着光突发交换网络的性能.本文首先介绍了光突发交换技术的原理,然后分析了光突发交换技术的现状及存在的问题,最后探讨了光突发交换中的路由技术及其发展.