光网络中的波带交换技术

波分复用光网络已成为广域骨干网最可行的体系解决方案.波带交换(WBS)因其能减小光交叉连接器的端口数、控制复杂性和连接费用等,引起了广泛的关注.文章指出了WBS和传统波长路由的不同之处,对WBS的两种多粒度光交叉连接器结构进行了分析.文中还提出了基于WBS的各种方案和光路成组策略,讨论了WBS网络中的波带转换和故障恢复问题.     

多域光网络联合路由保护算法

研究了多域光网络中的路由保护问题。为了避免多域光网络通路保护二步算法可能导致的多域陷阱问题,提出了一种基于Suurballe算法扩展的多域联合路由保护算法。仿真表明,相比传统的多域通路保护二步算法,该算法资源利用率高,阻塞率低,平均每连接跨域数小。     

An Inter-domain Routing and Signaling Scheme for Optical Mesh Networks

An inter-domain routing and signaling scheme based on the OBGP protocol for WDM networks with a mesh topology is proposed in the paper. For mesh networks with wavelength conversion, inter-domain routing and signaling are realized by introducing a new message based on an optimal path identifier (OPI) and by establishing the corresponding message-exchange procedures. Considering the wavelength continuity constraint, a strategy called improved destination wavelength assignment (IDWA) combined with the OPI-based message is presented to establish a lightpath dynamically. The scheme is verified on the NSFNET and the CERNET by simulation. Results show that the blocking performance of a non-wavelength-conversion network is even a little lower than that of a wavelength-conversion network.     

光的微电机系统在光通信网的应用

先简单表明未来的光通信网必然需要最合适的光器件。解释光的“微电机系统”有很好的发展前途。文中依次介绍光的微电机系统在光波长路由器、在光交叉连接和在光交换设备中的广泛应用。     

多并发流无线网状网中的机会路由算法

现有机会路由选择未考虑数据流的分布,可能使候选节点空闲或过载,导致网络吞吐量提升有限.本文将多并发流的机会路由描述成一个凸优化问题,基于对偶和子梯度方法,提出分布式联合候选节点选择和速率分配的多流机会路由算法(Opportunistic Routing for Multi-Flow,ORMF).该算法迭代进行流速率分配,并在速率分配过程中完成候选节点选择.实验结果表明,与基于期望传输次数和期望任意传输次数指标的机会路由相比,ORMF平均可提高33.4%和27.9%的汇聚吞吐量.     

无线网状网路由判据研究

无线网状网(WMN)相关技术的研究非常活跃,路由判据的设计是提高其性能的关键。WMN具有同时拥有移动节点和静态节点及每个节点可能配置多信道等特点。对路由判据的设计提出了特别的要求:必须保证网络的稳定性;保证最小权重路由有最佳性能;该路由可以通过多项式复杂度算法得到;得到的路由中无转发环路。研究了几种现有的路由判据,包括HOP、ETX、ETT、WC-ETT、MIC、mETX、ENT。MIC能较好适应WMN,但需要在自由因子的设定及网络中加入移动节点后的性能方面做改进。对路由判据的跨层、多准则设计是以后的研究方向,基于此文中也对几个改进方案进行分析。     

WMN多路径路由算法安全性分析与仿真

高效、安全的路由机制是保证无线网状网络(WMN)正常工作的一个重要因素。对WMN中的多径路由(MPR)算法进行了研究。由于MPR算法存在路由分离性约束,提出了一种基于转移概率的随机路由(SR)算法,并对这两种算法进行了仿真。仿真结果表明:在节点转发次数的标准方差和最高截获率两个性能指标方面,SR算法均优于MPR算法,这说明与MPR算法相比,所提算法进一步增强了WMN网络的路由安全性。     

Cross-Layer Design Based Optimized Link State Routing Protocol for Wireless Mesh Networks

A proactive routing protocol CL-OLSR (cross-layer based optimized link state routing) by using a brand-new routing metric CLM (cross-layer metric) is proposed. CL-OLSR takes into account four link quality impact factors in route calculation through the cross-layer operation mechanism: the node available bandwidth, the node load, the link delivery rate, and the link interference, and thus the effect of route selection is optimized greatly. The simulation results show that the proposed CL-OLSR protocol can not only improve the network throughput to a large extent, but also reduce the end-to-end delay, while achieving load balance route results.     

全光通信网技术

本文对全光网的概念和关键技术做了简要说明，并介绍了具有代表性的全光网络，最后对各个网络的技术进行了比较，并同了全光网发展的一些主要障碍。     

一种基于OBGP协议的光网络域间路由的新型机制

本文提出一种采用光边界网关协议(OBGP)实现WDM光格状网的域间路由的新型机制;该机制基于最小跳选择策略建立最优化路径的思想,同时引进"迂回路由"策略和"并行信令"方式,实现了动态、分布式的光通道确立过程.在OPNet平台上针对两种网络拓扑进行仿真实验,结果表明:该机制能够在网络繁忙时期降低阻塞率,提高网络性能;同时发现:网络规模、单信道波长数以及网络负载等网络参数对于网络性能具有一定的影响.     

Wavelength Conversion in WDM Optical Networks: Strategies and Algorithms for Limiting the Number of Converters in the Optical Cross-Connects

This paper considers the problem of wavelength conversion in optical networks using wavelength division multiplexing technique. In the previous literature, two main wavelength routing and assignment strategies have been introduced: wavelength path (WP) and virtual wavelength path (VWP), depending on whether the signal stays on the same wavelength or is converted to another during its travel throughout the network. While the former method does not require any wavelength conversion, the latter needs wavelength conversion in each optical node and, in particular, a wavelength converter per each signal handled by the node itself. From the previous literature emerged that the VWP leads to optical cross-connect (OXC) with lower dimensions compared to the ones required by the WP scheme, and that the difference between the WP and VWP schemes increases as the number of wavelengths carried by each fiber increases. In this paper a new strategy is introduced, named partial virtual wavelength path (PVWP), with the related wavelength routing and assignment algorithm, which makes limited use of wavelength conversion compared to the VWP scheme, and allows the same advantages of VWP to be attained with lower OXC dimensions. The paper reports a comparative analysis among the different strategies, considering both the cases of a network without failures and a network with the possibility of failure restoration. The main result is that the proposed PVWP strategy allows the same advantages of the VWP scheme with a strongly reduced number of wavelength converters (around 5% of the number required by VWP scheme). This figure does not vary appreciably if failure restoration is considered. The new strategy can be adopted by using an opportune OXC architecture, as illustrated in the paper, which allow a limited number of converters to be shared among all the channels as a common pool.     

无线Mesh网络路由协议——多射频质量源路由（MR-LQSR）协议

无线Mesh网络使用传统的基于最短路径的移动Ad Hoc网络路由协议并不能获得良好的性能,为此提出了一种新的无线Mesh网路由协议——MR—LQSR算法及新的路由判据——WCETT．能在吞吐量与延时之间获得一种平衡。     

智能光网中的联合路由

在IP/MPLS智能光网络中的LSP路由分为独立路由和联合路由两类。由于综合考虑了光层和IP层的可用资源信息和拓扑信息,联合路由能够提供比独立路由方案更高的资源利用率。文中提出了联合路由算法的设计目标,综述了联合路由算法的研究现状,并给出了下一步的研究方向。     

无线Mesh网络跨层路由技术研究

无线Mesh网络(WMN:wireless mesh networks)作为一种新型的无线网络,成为近几年研究的热点。由于无线信道不稳定等特性,如何设计WMN的路由协议成为决定其性能的关键因素之一。近几年来的研究表明,通过跨层设计的方式综合其他层的重要参数来实现路由选择,能够很好地解决这一难题。介绍了几种先进的跨层路由设计方案,总结了现有的跨层路由协议的优缺点,并对如何设计并实现跨层路由协议进行了分析和总结。     

波分复用光网络中的波长路由分配策略

路由选择和波长分配是WDM光传输网中非常重要的问题.本文结合交叉连接节点,提出了一种基于最短路径的动态路由选择方案;然后利用这种动态的路由选择策略,以网络的阻塞性能为优化目标分配波长,达到充分利用网络资源的目的.计算机仿真结果表明,无论在单纤或者多纤WDM光传输网络中,利用这种策略的RWA算法优于传统的固定路由和单纯动态路由算法     

Distributed Routing Based on Minimum End‐to‐End Delay for OFDMA Backhaul Mobile Mesh Networks

In this paper, an orthogonal frequency division multiple access (OFDMA)‐based minimum end‐to‐end delay (MED) distributed routing scheme for mobile backhaul wireless mesh networks is proposed. The proposed scheme selects routing paths based on OFDMA subcarrier synchronization control, subcarrier availability, and delay. In the proposed scheme, OFDMA is used to transmit frames between mesh routers using type‐I hybrid automatic repeat request over multipath Rayleigh fading channels. Compared with other distributed routing algorithms, such as most forward within radius R, farthest neighbor routing, nearest neighbor routing, and nearest with forwarding progress, simulation results show that the proposed MED routing can reduce end‐to‐end delay and support highly reliable routing using only local information of neighbor nodes.     

无线Mesh网络QoS路由度量研究

无线Mesh网络的研究非常活跃,针对网络路由选择已经提出了一些路由选择度量。本文对各种路由度量及优缺点进行了详细的分析,并在此基础上,给出了一种新的路由度量方式并展望无线Mesh网络QoS路由度量选择的发展方向。     

无线Mesh网络路由协议研究

无线网状网络（WMN）的路由协议是无线Mesh领域的研究重点。文章先对移动Ad hoc网络的经典路由协议进行分类和比较,在此基础上总结了将Adhoc路由协议应用于无线Mesh网络的几种主流的改进思路,最后对各种改进思路的代表性路由协议进行了分析和讨论。     

无线网格网中一种基于树的先验式路由协议

Wireless Mesh Network (WMN) is seen as an effective Internet access solution for dynamic wireless applications . For the low mobility of mesh routers in WMN, the backbone topography can be effectively maintained by proactive routing protocol. Preproposals like Tree Based Routing (TBR) protocol and Root Driven Routing (RDR) protocol are so centralized that they make the gateway become a bottleneck which severely restricts the network performance. We proposed an Optimized Tree-based Routing (OTR) protocol that logically separated the proactive tree into pieces. Route is partly computed by the branches instead of root. We also discussed the operation of multiple Internet gateways which is a main issue in WMN. The new proposal lightens the load in root, reduces the overhead and improves the throughput. Numerical analysis and simulation results confirm that the performance of WMN is improved and OTR is more suitable for large scale WMN.     

WMN中一种基于干扰感知的负载均衡路由协议

无线信道干扰和负载分布的不均衡严重影响无线Mesh网络吞吐量、端到端延时和资源利用率。在已有基于信噪比和邻居节点个数的干扰模型基础上,进一步研究了无线Mesh网络的链路干扰。在综合考虑了无线Mesh网络流间干扰和和流内干扰的基础上,提出路由判据PIL（Path Interfer-ence Level）。在此基础上,提出一种新的基于干扰感知的负载均衡路由协议IA-DSR（Interference-Aware DSR）。IA-DSR考虑无线网络拥塞并选择受到干扰最小的路径。仿真结果表明,在不显著增加开销的情况下,IA-DSR可以有效地提高网络的整体吞吐量,降低网络端到端时延和丢包率。