RPR技术及其在MSTP中的应用

基于SDH的城域多业务传送平台（MSTP）是当前构筑城域光网络的主要技术之一。弹性分组环（RPR）是一种新的MAC层协议，是为优化IP包的传输、构建光互联网而提出的，目前正由IEEE８０２郾１７工作组进行标准化。１RPR和MSTP产生的技术背景当前城域网建设所采用的技术主要分为３类：传统SDH技术、以太网技术和MSTP技术。传统SDH／SONET及其环网结构在城域网中得到广泛应用，提供完善的网络性能监测和自愈保护功能。SDH系统是一种电路模式传送技术，非常适合传送城域网中６４kbit／s的话音业务和提供以２Mbit／s为单位的固定…     

城域网中SDH多业务传送的实现

城域网中为了更好地利用SDH，支持多业务传送，需要在SDH平台上添加数据传输的能力。通用成帧规程、虚级联和链路容量调整机制三项新技术使得SDH设备实现了数据业务和话音业务的综合传输．SDH发展成了多业务传送平台。通过分布控制系统和中心控制式网络管理还可以实现SDH业务带宽的增加和调整。     

城域传送网骨干层未来发展趋势

基于对现有移动传送网现状的分析,对于专线、话音等小颗粒业务,目前的SDH/MSTP网络已经提供了完善的解决方案。但面对爆炸式增长的大颗粒带宽业务,现有的网络和技术则无法很好的解决。城域网必须具备大容量、高带宽、多业务、高可靠性等能力,从而实现骨干层层面的宽带IP化业务支持能力。     

打造智能的城域光网络——访烽火通信科技股份有限公司总裁助理杨壮

众所周知，传统的SDH网主要是针对话音业务而建设的，随着近几年数据业务的迅速膨胀，如何在网络中有效承载和传送数据业务已成为运营商关注的焦点。目前，运营商普遍都建立起庞大而完善的面向TDM业务的SDH网络，完全抛开原有的网络资源，重新建设面向数据业务的网络是不太现实的。因此，在SDH技术上增加对数据业务的支持，特别是对以太网的支持，成为运营商解决数据业务在网络中传送中最有效的解决方案。基于SDH之上的MSTP技术因能有效承载语音、数据等多种类型的业务而成为城域网建设的主流技术，随着它的日益发展和在实际网络中的不断应用，业务互通及标准化问题逐渐显现。     

RPR技术及其在MSTP中的应用

一、RPR和MSTP产生的技术背景 当前城域网建设所采用的技术主要分为三类:传统SDH(同步数字系列)技术、以太网技术和MSTP(多业务传送平台)技术。 传统SDH/SONET及其环网结构在城域网中得到广泛应用,它提供完善的网络性能监测和自愈保护功能,是一种电路模式传输技术,非常适合传输64kbit/s     

浅析城域网的发展与技术选择

本文结合城域网的基本概念，介绍了城域光传送网的3种主要技术：城域WDM环网、以SDH为基础的多业务传送平台（MSTP）、弹性分组环（RPR），阐述了城域网的建设和发展。[编者按]     

MSTP技术现状及应用

近年来城域传送网的建设方兴未艾，随着通信网络运营商的竞争重点已从骨干网转向城域网，建立高效经济的支持多业务的城域传送网已经成为运营商的共同目标。从技术的角度，多种技术层出不穷，城域光传送网的主要技术包括SDH、以SDH为基础的多业务传送平台（MSTP）、城域波分复用（WDM）环网、粗波分复用（CWDM）以及弹性分组环（RPR）。城域宽带无线接入技术主要有LMDS、     

城域MSTP建设的思考

对当前城域网的业务需求进行了分析，提出四类城域网建设解决方案。重点介绍了基于SDH的城域多业务传送平台(MSTP)技术的工作原理及发展过程，并从网络结构、业务归集能力、安全性、管理维护、兼容性等五个方面探讨了城域MSTP建设应该注意的问题。     

传送网又一轮的竞争重点——城域传送网

城域网业务主体正在发生深刻变化，业务类型的变化必然带来物理层基础网络的变化。运营商面临着对城域传送网络重新规划设计和建设的任务。与骨干网相比，城域网具有业务种类多、业务调度转接多、业务流量变化大的特点，其应用的技术也呈多样化。本文从城域传送网的特点、分层结构、技术等多方面讨论城域传送网的发展，并对运营商的城域网组网策略进行讨论。     

城域传送新技术-多业务传送平台(MSTP)

城域网是目前各大运营商建设的热点，传输网实现方案是其中的关键技术。本首先介绍了目前传输网采用的主要技术SDH和DWDM；而后重点讨论了为各运营商看好的传送新技术——多业务传送平台，对其原理、特色、优势进行了分析；最后对城域传送技术的下一步发展趋势进行了展望。     

The building blocks of a data-aware transport network: deploying viable Ethernet and virtual wire services via multiservice ADMs

SONET/SDH technologies constitute the core transport infrastructure of major telecom service providers worldwide. As the percentage of packet-oriented traffic in the overall traffic demand continues to rise, prompted by the widespread adoption of the Internet protocol suite, and recently by the fast adoption of Ethernet services, there is increasing pressure to improve the service provider's transport infrastructure in ways that make it data-aware and cost-effective for packet-oriented applications. Steps in this direction include the adoption of native physical interfaces, for Ethernet and storage area networks as service interfaces, or full integration of packet switching capabilities from Ethernet, resilient packet ring, and MPLS technologies. This article discusses the emerging building blocks for next-generation data-aware transport networks and next-generation transport network elements.     

Packetized voice/data integrated transmission on a token passingring local area network

The performance of a token-passing ring network with packetized voice/data mixed traffic is investigated through extensive simulations. Both data and voice users are modeled in the simulations. Data users produce bursty traffic. Voice traffic is modeled as having alternating talkspurts and silences, with generation of voice packets at a constant rate during talkspurts and no packet generation during silence periods. Token passing ring local area networks are shown to effectively handle both voice and data traffic. The effects of system parameters (e.g. voice packet length, talkspurt/silence lengths, data traffic intensity, and limited exhaustive service disciplines) on network performance are discussed     

MSTP应用和发展展望

在概述MSTP演进路线的基础上,文章从运营角度探讨了今后一段时期内MSTP设备应具有的功能和新业务支持能力,如VLAN组网能力、业务分类和服务质量(QoS)控制能力、多业务传送能力等.文章认为多业务传送节点(MSTP)继承了同步数字系列(SDH)的技术优势,同时又能承载以太网、IP和ATM等多种数据业务,并在同一个平台上实现统一的网络控制和管理,将发展成为城域传送网的主流技术.由于具有丰富的接口、灵活的带宽管理和服务质量保证机制,MSTP可很好地将传输技术与数据业务的发展需求结合起来,较好地解决电路和数据业务的综合传送,为电信运营商提供更加广阔的运营空间.     

Packet-aware transport for metro networks

Today's metro networks have evolved from the need to support traditional voice and private line services. However, the tremendous growth in access to frame relay, ATM, IP, and Ethernet services, coupled with the desire of enterprise customers to interconnect via Ethernet interfaces, suggests the need for a new approach. This article proposes a new architecture for packet-aware transport networks (PATN) that supports both packet and traditional TDM services and leverages an assemblage of emerging technologies to provide efficient aggregation and switching of packet traffic in metro networks. The PATN has the potential to provide significant cost savings to carriers by reducing the number of network elements, reducing transport costs through statistical multiplexing, and eliminating the need for redundant multiplexing operations.     

A summary of the HORNET project: a next-generation metropolitan area network

Metropolitan area networks are currently undergoing an evolution aimed at more efficiently transport of data-oriented traffic. However, the incoming generation of metro networks is based on conventional technology, which prevents them scaling cost-effectively to ultrahigh capacities. We have developed a new architecture and set of protocols for the next generation of metro networks. The architecture, named HORNET (hybrid optoelectronic ring network), is a packet-over-wavelength-division multiplexing ring network that utilizes fast-tunable packet transmitters and wavelength routing to enable it to scale cost-effectively to ultrahigh capacities. A control-channel-based media access control (MAC) protocol enables the network nodes to share the bandwidth of the network while preventing collisions. The MAC protocol is designed to transport variable-sized packets and to provide fairness control to all network end users. The efficiency and the fairness of the MAC protocol is demonstrated with custom-designed simulations. The implementation of the MAC protocol and the survivability of the network have been demonstrated in a laboratory experimental testbed. The article summarizes the accomplishments of the HORNET project, including the design, analysis, and demonstration of a metro architecture and a set of protocols. The HORNET architecture is an excellent candidate for next-generation high-capacity metro networks.     

MSR（ITU-T X.87/Y.1324）体系构架与系统特性

针对光城域网对综合业务的电信级需求，以城域网三网业务融合传送为主要领域，以基于弹性分组环RPR实现多业务传送为主要手段，研究了多业务传送与交换的简化方法，介绍了自主国际标准ITU-T X．87／Y．1324的协议要点、组网拓扑结构、传输架构、系统节点的组成和MSR通用帧格式。通过与RPR的比较，得出如下结论：MSR解决了语音、数据和视频等多业务(支路)分别在RPR各节点上，下的传送、支路组播、支路保护和性能监测问题。MSR成本较低，而且在同一网络平台上提供语音、数据和视频等支路业务需要这样的功能，它是目前基于分组的城域网多业务传送和出租的有效方法。     

Hierarchical Ethernet Transport Network Architecture for backhaul cellular networks

Cellular traffic has been going through major changes in recent years. With the introduction of broadband services in 3G/4G and the continuously increasing provided data rates in high-speed packet access and Long Term Evolution (LTE), a broad range of cellular applications has emerged, changing the characteristics of cellular traffic. The traditional circuit-switched voice traffic has been taken over by packet-oriented data traffic. This shift in traffic has driven operators to prefer packet-oriented network technologies over circuit-switch technology when implementing their cellular networks. The current offered technologies, including PBB-Traffic Engineering and MPLS-TP, lack important functionality required for LTE such as automation (simple management), traffic engineering, protection, Quality of Service, and scalability. We propose a scalable Hierarchical Ethernet Transport Network Architecture (HETNA), a layer 2 transport technology that addresses these issues and brings a viable solution for cellular networks. The suggested architecture can handle streaming, real-time, multicasting, and other applications. Both connection-oriented transport services and connectionless-oriented services are supported. HETNA was simulated and prototyped, showing significant improvements over regular Ethernet in terms of buffers and control messages that enable this network to function.     

Packet CDMA versus dynamic TDMA for multiple access in anintegrated voice/data PCN

A comparative evaluation of dynamic time-division multiple access (TDMA) and spread-spectrum packet code-division multiple access (CDMA) approaches to multiple access in an integrated voice/data personal communications network (PCN) environment are presented. After briefly outlining a cellular packet-switching architecture for voice/data PCN systems, dynamic TDMA and packet CDMA protocols appropriate for such traffic scenarios are described. Simulation-based network models which have been developed for performance evaluation of these competing access techniques are then outlined. These models are exercised with example integrated voice/data traffic models to obtain comparative system performance measures such as channel utilization, voice blocking probability, and data delay. Operating points based on typical performance constraints such as voice blocking probability 0.01 (for TDMA), voice packet loss rate 10^-3 (for CDMA), and data delay 250 ms are obtained, and results are presented     

分组传送网环网保护机制的探讨

随着3G移动通信系统IP化和面向IP的全业务时代的到来,城域传送网络正面临着由基于电路交换的SDH网络向基于分组交换的电信级分组传送网（PTN）的逐步演进趋势。保护是PTN满足运营商级需求的重要特性。本文介绍了PTN各种保护机制,重点针对应用在移动回传网络中的PTN环网保护方式进行了探讨,并对各种故障类型触发保护的实现机制进行了分析。