光纤同步网讲座（六）：SDH／SONET网络建设与管理

文章首先概述了ＳＤＨ／ＳＯＮＥＴ网络的规划原则和电信管理网原理结构，接着着重论述了ＳＤＨ／ＳＯＮＥＴ网络结构与管理、ＳＤＨ／ＳＯＮＥＴ管理信息模型以及ＳＤＨ／ＳＯＮＥＴ管理网络的主要功能，最后给出ＳＤＨ／ＳＯＮＥＴ网络管理平台的一般组成，指出它是扩大管理能力，实现智能化网络的保证。     

PDH,SDH／SONET技术及其应用（二）

ＰＤＨ，ＳＤＨ／ＳＯＮＥＴ技术及其应用（二）隆克平ＰＤＨ，ＳＤＨ／ＳＯＮＥＴＴｅｃｈｎｏｌｏｇｙａｎｄＩｔｓＡｐｐｌｉｃａｔｉｏｎ￥ＬｏｎｇＫｅｐｉｎｇ二、ＰＤＨ，ＳＤＨ，ＳＯＮＥＴ的技术特点及区别１、ＳＤＲ／ＳＯＮＥＴ的技术特点与ＰＤＨ相比，ＳＤＨ...     

SONET/SDH架构上的以太网传输方案

ＯＮＥＴ／ＳＤＨ架构固有的一些特性并不适合于传输ＩＰ业务，例如ＳＯＮＥＴ／ＳＤＨ固定的速率等级，与可变长度ＩＰ包不匹配且难以扩展；不适合于ＩＰ环境的开销等。但从市场的角度看，大多数运营商现有的网络大都基于ＳＯＮＥＴ／ＳＤＨ，仅美国就至少有十万个ＳＯＮＥＴ环，世界其余地区的总和是美国的两倍。而且对于国内的电信运营商来说，尽管互联网业务量飞速增长，话音业务仍是其收入的主体。因此，经济的因素使得运营商不会完全放弃ＳＯＮＥＴ／ＳＤＨ技术，而去发展还不能立即带来经济效益的新技术。随着新技术的发展，基于下一…     

以太网到SONET/SDH映射芯片

安捷伦科技公司推出其创新产品———ＨＤＭＰ -３００１,以太网到ＳＯＮＥＴ／ＳＤＨ（ＥｏＳ）映射芯片。ＨＤＭＰ -３００１是一款通用芯片 ,运用该创新产品 ,网络和电信设备可为ＳＯＮＥＴ／ＳＤＨ网络同时提供局域网和广域网的接口 ,大大降低了覆盖多个地域的企业网络的运营维护成本。ＨＤＭＰ-３００１是由安捷伦科技与武汉邮电科学研究院共同研究开发的 ,也是安捷伦科技的ＳＯＮＥＴ／ＳＤＨ多协议芯片 (ＭＰＩＣ)系列中的第一款。ＭＰＩＣ可以将各种协议的信息映射到ＳＯＮＥＴ／ＳＤＨ中 ,为企业级用户将数据业务传送到ＳＯＮＥＴ…     

PDH,SDH／SONET技术及其应用（一）

本文论述了ＳＤＨ／ＳＯＮＥＴ技术产生和发展及应用，并从理论上对ＰＤＨＴ和ＳＤＨ／ＳＯＮＥＴ作了技术比较，此外，还介绍了ＳＤＨ传输网络结构和ＳＤＨ传送设备。     

S1240,HONET,EWSD交换机之间创建半永久性连接的方法

目前 ,银行、邮储的通存通兑业务多数是采用ＤＤＮ数据专线。ＤＤＮ专线稳定性好 ,但电信局需要投入大量的ＤＤＮ设备 ,如果利用交换机提供半永久性连接 ,既能实现该功能 ,又无需投入ＤＤＮ设备 ,可为电信局节约资金。以下介绍Ｓ１２４０交控机、华为接入网ＨＯＮＥＴ、ＥＷＳＤ交换机之间建立半永久性连接的创建方法。以沭阳局为例 ,Ｓ１２４０为汇接局 ,ＨＯＮＥＴ、ＥＷＳＤ为端局。１Ｓ１２４０与ＨＯＮＥＴ之间半永久连接的创建Ｓ１２４０:ＤＮ＝Ｋ′３５５６４４１,ＨＯＮＥＴ用户为３６３０１２４。（１）Ｓ１２４０半永久性连接的创…     

光纤同步网讲座（五）：同步光缆数字传输系统

这一讲首先概述了研究ＳＤＨ／ＳＯＮＥＴ传输网络性能的数字传输参考模型、系统的同步与定时，接着着重讨论了系统的误码性能和抖动特性、系统的有效性和可靠性，最后介绍ＳＤＨ／ＳＯＮＥＴ光缆传输系统对光纤传输介质的要求。     

TN64 10 Gbit／s传输平台与多波长光放大器

北电网络是第一个向市场提供１０Ｇｂｉｔ／ｓＳＯＮＥＴ／ＳＤＨ产品并通过单纤双向密集波分复在一根光纤上传输的供应商边套系统与已敷设的光纤完全兼容。目前,１０Ｇｂｉｔ／ｓＳ／ＤＭＳ传输系统系统与ＤＷＤＭ结合在一起,能够提供３２０Ｇｂｉｔ／ｓ的容量。     

ATM同步网络接口

首先介绍了ＡＴＭ基本概念、信元结构、接着详细讨论了ＡＴＭＳＤＨ／ＳＯＮＥＴ光缆系统接口，这里以Ｏｄｅｔｉｃｓ公司开发的ＡＴＭＳＤＨ／ＳＯＮＥＴ光缆线路接口模块为例说明了其性能特点、工作原理以及主要性能参数。     

一种新的集成自愈技术及其算法

本文首先提出了容量平衡优化（ＣＥＰ）、共享自愈环（ＳＳＲ）和分布式动态自愈网（ＤＳＨ）三者集成的自愈技术,提出了基于最短路由业务量阵（ＳＲＭＴ）的ＳＳＲ空闲容量分配算法,而对于ＤＳＨ,从端到端重选路由和网络资源利用率的观点看,基于通道恢复技术比基于链路恢复技术更有效,本文提出了基于通道恢复的集成自愈设计技术及其算法。数值结果表明：本文提出的集成自愈技术及其算法可有效地节约容量需求。     

A new synchronous digital hierarchical Bi-directional ring capacity design algorithm based on the shortest-route traffic matrix

In this paper, the concept of the Shortest-Route Traffic Matrix(SRTM) was first presented, and the generalized formula for computing ring capacity requirement in use of SRTM is given. Then, a new capacity design algorithm which is based on SRTM was presented for Synchronous Digital Hierarchical(SDH) Bi-directional Self-Healing Ring (BSHR). The algorithm simulation results demonstrate that this algorithm is very efficient for SDH BSHR capacity design and can make less project investment and make high utilization of lines and equipment. By means of the algorithm in this paper, capacity optimization assignment for SDH Hierarchical Self-Healing Ring (HSHR) and for ATM Virtual Path (VP)-based Self-Healing Ring (SHR) is also discussed.     

Wavelength Assignment to Minimize the Number of SONET ADMs in WDM Rings*†

Optical wavelength division multiplexing (WDM) rings are being deployed to support SONET/SDH self-healing rings. In such systems, multiple SONET/SDH self-healing rings are realized over a single physical optical ring through wavelength division multiplexing. The cost of such a system is dominated by the SONET add/drop multiplexers (ADMs). To minimize the system cost, algorithms must be developed to assign wavelengths to lightpaths in the system so that the number of ADMs required is minimized. This problem of optimal wavelength assignment to minimize the number of SONET ADMs is known to be NP-hard. Existing heuristic algorithms for this problem include the assign first heuristic, the iterative matching heuristic and the iterative merging heuristic. In this paper, we develop an integer linear programming (ILP) formulation for this problem, propose a new wavelength assignment heuristic, and evaluate the existing and the newly proposed heuristic using the ILP formulation. We conclude that the performance of the newly proposed heuristic is very close to optimal.     

同步光网络和同步数字系列大容量交叉的实现

文章介绍一种基于时分 空分 时分(T S T)结构的大容量SONET/SDH交叉单元的实现方法和应用.它涉及到高速串行I/O、交叉结构以及设计考虑.它可以支持严格无阻塞的单播业务,也可以支持重配置无阻塞的双播业务.实现双播功能是SONET/SDH的单向通道保护环(UPSR)/双向复用段保护环(BLSR)的最基本要求.     

SDH/ATM双向自愈环的生存性定量分析方法

本文推导出了ＳＤＨ／ＡＴＭ双向自愈环在链路失效、节点失效及链球节点混合失效、节点失效及链路节点混合失效三种模型情况下的网络生存性函数,从导出的网络生存性函数可以方便地求出生存率的均值、最坏生存率、ｒ百分比生存率及零生存率等单个生存性测度。同时对导出的生存性函数结果进行了分析,结果表明本文的分析方法符合实际情况,是切实可行的,为分析和设计高生存性通信网络提出了统一的实现的方法。     

弹性分组环(RPR)技术分析

弹性分组环(Resilient Packet Ring)技术是主要结合了SONET／SDH和以太网的优点而形成的一种基于分组交换的城域网技术。本从讨论SONET／SDH和以太网技术的优缺点中引出弹性分组环的出现背景、分析了RPR的技术特点和实现方法。     

A Lagrangian-Relaxation Based Network Profit Optimization For Mesh SONET-Over-WDM Networks

In Wavelength Division Multiplexing (WDM) networks, the huge capacity of wavelength channels is generally much larger than the bandwidth requirement of individual traffic streams from network users. Traffic grooming techniques aggregate low-bandwidth traffic streams onto high-bandwidth wavelength channels. In this paper, we study the optimization problem of grooming the static traffic in mesh Synchronous Optical Network (SONET) over WDM networks. The problem is formulated as a constrained integer linear programming problem and an innovative optimization objective is developed as network profit optimization. The routing cost in the SONET and WDM layers as well as the revenue generated by accepting SONET traffic demands are modelled. Through the optimization process, SONET traffic demands will be selectively accepted based on the profit (i.e., the excess of revenue over network cost) they generate. Consiering the complexity of the network optimization problem, a decomposition approach using Lagrangian relaxation is proposed. The overall relaxed dual problem is decomposed into routing and wavelength assignment and SONET traffic routing sub-problems. The subgradient approach is used to optimize the derived dual function by updating the Lagrange multipliers. To generate a feasible network routing scheme, a heuristic algorithm is proposed based on the dual solution. A systematic approach to obtain theoretical performance bounds is presented for an arbitrary topology mesh network. This is the first time that such theoretical performance bounds are obtained for SONET traffic grooming in mesh topology networks. The optimization results of sample networks indicate that the roposed algorithm achieves good sub-optimal solutions. Finally, the influence of various network parameters is studied.     

Dynamic bandwidth-allocation and path-restoration in SONETself-healing networks

This paper presents a new scheme for real-time bandwidth allocation and path restoration (BARS) in mesh networks via SONET wideband digital cross-connect systems (WDCSs) in response to demand and load dynamics and link and/or node failure(s). The scheme dynamically maximizes bandwidth allocation while ensuring full service restorability. Since the physical network capacity is limited, sometime not all the demand can be accommodated under the full restorability requirement. This demand in SONET BARS is rejected fairly at the network boundary even if capacity for allocation is available. Bandwidth allocation and fair demand admission are optimized jointly under the full restorability requirements. The implementation of SONET WDCS does not need excessive storage. An efficient parallel algorithm for solving the optimization problem is also presented. The algorithm produces superior spare capacity assignments compared to the results in the literature     

Solving large-scale SONET network design problems using bee-inspired algorithms

In the past years, the number of users of Internet-based applications has exponentially increased and consequently the request for transmission capacity or bandwidth has significantly augmented. When managed properly, the ring networks are uniquely suited to deliver a large amount of bandwidth in a reliable and inexpensive way. In this paper, we consider two problems that arise in the design of optical telecommunication networks, namely the SONET Ring Assignment Problem (SRAP) and the Intraring Synchronous Optical Network Design Problem (IDP), known to be NP-hard. In SRAP, the objective is to minimise the number of rings (i.e., DXCs). In IDP, the objective is to minimise the number of ADMs. Both problems are subject to a ring capacity constraint. To solve these problems, we propose two bee-inspired algorithms: Hybrid Artificial Bee Colony and Hybrid Bees Algorithm. We hybridise the basic form of these algorithms with local search, in order to refine newly constructed solutions. We also perform comparisons with other algorithms from the literature and use larger instances. The simulation results verify the effectiveness and robustness of the proposed algorithms.     

Effective wavelength assignment algorithms for optimizing designcosts in SONET/WDM rings

In high-speed wavelength-division-multiplexed synchronous optical network (SONET) ring networks, the terminal equipment costs associated with electronic multiplexing can be predominantly high. Placing a wavelength add-drop multiplexer (WADM) at each network node allows certain wavelengths to optically bypass the node without being electronically terminated. This approach can effectively reduce the total equipment cost if connections and channels are appropriately assigned in traffic grooming. In this paper, we present a series of wavelength optimization and wavelength assignment algorithms with the objective to optimize the number of required SONET add-drop multiplexers and yet minimizes the number of wavelengths in both unidirectional and bidirectional rings under an arbitrary grooming factor. In our analysis, we have considered both uniform and general nonuniform all-to-all network traffic. As a simple model for realistic traffic patterns, a special case of nonuniform traffic, distance-dependent traffic, is analyzed in detail. Significant ADM savings are observed for different traffic scenarios using our proposed algorithms     

利用弹性分组环技术建设新一代城域网

弹性分组环(RPR)技术是融合SDH/SONET和以太网的优点而形成的一种基于分组交换的网络技术,它已成为建设新一代城域网、实现三网合一的主要技术之一.对RPR进行介绍并与其他技术作比较,讨论了RPR的优点、关键技术及发展前景.