业务光网络中光服务等级协定的研究

从业务光网络的角度对比服务等级协定(SLA)定义了光服务等级协定(O-SLA)的框架结构,在此基础上重点分析了O-SLA协商机制并提出一种动态协商的概念,对动态协商机制的实现流程进行了分析研究.随后总结了O-SLA得以有效实施的关键技术,并提出一种支持区分服务的O-SLA实施流程,此流程对于向端用户提供可定制化的光层业务提供了一种新思路.     

一种支持区分业务的智能光网络RWA方法北大核心

针对差异化的用户QoS(服务质量)需求,提供支持区分业务的RWA(路由和波长分配)算法是光网络当前研究的重点。文章提出了一种改进的支持区分服务的智能光网络GWAS(分组波长分配策略),针对不同等级的业务采用动态可调整的波长分组方案以实现差异化QoS。仿真结果表明,GWAS方案可以保证高优业务比低优业务具有更好的性能:在每根光纤复用9波长和160波长情况下,Mesh与NSFNET网络中高优业务比低优业务的阻塞率在相同业务负荷下最大降低24%与18%和15%与10%。     

下一代传送网的技术发展趋势浅析

传送网是整个电信网的基础，它为整个网络所承载的业务提供传输通道和传输平台。随着近年来电信业务对带宽需求的不断提高，光传送网络的规模在不断扩大，为业务网提供了巨大的带宽资源，同时在网络的生存性，可扩展性方面也有了巨大的进步。作为网络的传送层面，下一代传送网的目标就是为了满足下一代网络的传送需求。结合下一代网络的特征，如：基于分组技术，能够提供包括电信业务在内的多种业务；在业务相关功能与传送下层相关功能分离的基础上，能够利用多种宽带，有QoS支持能力的传送技术；下一代传送网应当满足从分组到波长的传送需求，同时支持多种业务，利用高速率，大容量的传送技术提供充足的带宽资源；具有端到端的业务等级和透明的传输能力：引入控制平面，解决网络智能性和动态性的结合，同时提供与传统网络互通的能力。总之，下一代传送网的特征将随着下一代网络和业务的发展而逐步明确，与业务的密切结合是下一代传送网的一个重要特征。[编者按]     

PTN网络中业务传输质量保证

在电信业务IP化趋势推动下,传送网承载的业务从以TDM为主向以IP为主转变。未来的市场业务不只是单纯的话音,视频,Internet,在线游戏等新业务也将层出不穷。PTN技术是IP/MPLS,以太网和传送网3种技术相结合的产物,具有面向连接的传送特征,适用于承载电信运营商的无线回传网络,以太网专线,L2VPN以及IPTV等高品质的多媒体数据业务。中兴通讯股份有限公司的《PTN网络中业务传输质量保证》一文介绍了端到端QoS,OAM和保护。为了支持具有不同服务需求业务,传送网络必须能够区分出不同的业务类型,进而为之提供相应等级的服务。     

贵阳本地传送网现状及存在的问题

城域传送网是可覆盖城市及郊区范围的提供丰富业务和支持多种通信协议的一个通用的传输平台。随着对业务种类和带宽需求的进一步增长,城域传送网必须要灵活可靠、具有大容量和良好的可扩展性、支持多协议和多业务、有灵活的电路调度和业务管理能力,具有向下一代智能光网络演进的能力。针对研究课题的实际需要,对贵阳铁通城域传送网的现状分析、现有传送网存在的问题探讨以及建议方案,确保改造后的城域网各层的容量能够满足贵阳铁通今后的发展需要。     

IP over WDM网光层QoS业务映射模型设计

在IP over WDM网络中,WDM光网作为底层传送网络,目前还不能完全解析IP层对业务QoS区分等信息.针对IP和WDM网络中两种不同的QoS机制,应用IP网络差分服务模式,通过UNI接口汇聚来自IP网络的流量,将其映射为光域中相似的业务需求,在光域中为不同QoS业务提供不同QoS保障的光连接通道,实现了WDM网络层的QoS区分服务.     

实现差分服务的家庭网络技术浅析

家庭网络在给运营商带来新的利润增长点的同时，也给运营商提出了新的挑战：不同的业务对网络的要求呈现不同的特点，这就要求运营商在为用户提供多业务的同时，还需考虑如何通过一定的技术手段构建差分服务的家庭网络，对家庭网络中不同等级的用户和不同等级的业务进行区分，并对承载网络进行相应的优化，以实现用户业务端到端的高质量保证，从而提升用户的业务感知和业务体验，提升宽带价值。家庭网络的差分服务涉及到家庭网关的业务区分与标记、多业务承载与映射、策略转发、带宽保障与限制等一系列技术，本文将分别对具体实现技术进行分析。[编者按]     

全业务交换光分组传送体系架构研究

从网络平滑演进的角度看,基于分组传送同时兼容现有TDM传送技术的"全业务交换传送"的体系架构是实现光传送网向分组化方向演进的必然选择,也是电信运营商关心的主要问题之一.文章主要讨论了基于分组传送的全业务交换传送的体系结构及其实现方案,该体系结构的关键是在电层引入基于分组的T-MPLS交换技术,解决光传送网对分组业务的承载问题.该体系架构能够满足各种网络业务的传送需求,融合了数据、电路和光层传送功能于一体,支持数据/TDM/波长等不同技术信号的交换.     

MPLS VPN差别化服务的实现技术模型及应用

为了满足互联网接入业务的服务质量需求,改变缺乏区分服务BGP/MPLS VPN网络的Qos的现状,提出了MPLS VPN网络的差别化服务应用模型,引入区分服务感知的流量工程(DS-TE)应用模型,通过MPLS Differ Serv模型在PE端的应用和DS-TE模型实现最小带宽的保证,从而实现高优先级业务服务质量的同时实现了优化网络资源的目的。     

LSON组网中的保护恢复机制

光传送网正逐步从单纯的传送平台演进为与上层业务网紧密结合的综合网。为使网络更有效快速地服务于最终用户，运营商需要构筑新一代的光传送网，通过ASON智能光网络技术将核心网和综合业务传送网结合在一起，提供全新端到端的业务服务和管理模式。     

基于QoS的3G网络系统设计与研究

为了有效地解决无线通信网络在宽带业务不断增加时产生的拥塞问题,提出了将区分服务模型应用于第三代移动通信网络以满足不同业务对QoS的需求。详细分析了区分服务模型的关键技术以及区分服务模型的系统结构,将区分服务模型和第三代移动通信分组域核心网系统结合起来,设计了支持QoS的第三代移动分组域核心网络。实验表明提出的模型较好地解决了第三代移动网络分组域核心网的QoS问题,提高了对不同业务的服务质量。     

A programmable optical network testbed in support of C-RAN: a reliability study

With both mobile network services and related data traffic volume on the rise, reliability of the radio access network is of the essence. A number of radio functional splits are defined by 3GPP to offer increased flexibility of implementation and feasibility of new mobile network services. For example, it is possible to implement certain radio functions in the Cloud, an architectural solution referred to as C-RAN. C-RAN solutions require highly reliable backhaul and fronthaul network designs. This paper describes PROnet, a programmable optical software-defined network testbed, which has been upgraded to offer backhaul and fronthaul transport capabilities in support of C-RAN functionalities with increased reliability. The testbed is upgraded with a specially designed 1 + 1 protection mechanism at the Ethernet layer in order to meet the stringent network round-trip requirements imposed by one of the C-RAN functional split options on the fronthaul.

     

Architecting the services optical network

In this new millennium, the most valuable commodity will be information, as seen by the surge in demand for faster access technologies such as cable modems, xDSL, and wireless data. The tremendous growth in data traffic, particularly that associated with the Internet, is changing the way it is carried over public and private networks. Together with the rapid advances in optical networking technology and the spawning of a new category of wavelength services stimulated by new high-speed data requirements, this is dramatically changing network architectures and the relationship between network service providers and their customers. Incumbent carrier globalization and new carrier entry require support for a broader set of business models and range of service interfaces. The growth and expansion of networks imply a greater need for more scalable solutions and more automation for network maintenance. An intelligent optical core optimized for service optical networking, the services optical network, needs to take the best aspects of both the transport and data networking domains to meet the above needs. This article focuses on architecting the services optical network to meet the challenges of optical data networking, and includes a snapshot of supporting standardization activities     

基于多智能体深度强化学习的智能电网光网络切片方案

为了提高光网络对大规模、差异化电力业务的资源分配能力,降低大规模业务的算法训练时间,提出了一种基于多智能体深度确定性策略梯度算法的智能电网光网络资源分配方案。该方案考虑大规模和差异化电力业务,将智能电网光网络建模成多智能体系统,以最大化电网公司收益为目标,建立了智能电网光核心网络切片模型,进行网络资源分配优化,并采用条件判断映射,简化了优化问题。同时,把不同业务部署到不同智能体中进行运算,以降低训练时间,满足网络实时性需求。仿真结果表明,该算法具有更大的奖励、更低的成本、时延和训练时间。     

下一代光网络的发展和关键技术

近年来，随着经济的发展和计算机的普及，Internet业务出现了爆炸性的增长，现有的网络应付大量的数据业务和各种类型的服务业务已显得有些力不从心。为了适应未来发展的需求，并针对IP业务的主导地位和光传输技术的发展，下一步不仅要提高传输链路的带宽和利用率，还要提高光网络的智能性，以满足IP业务对传输和交换系统的要求。因此我们提出发展以IP层和光层融合的下一代智能光网络（OTN）。并针对下一代光网络的发展和关键技术进行了简单的阐述。     

A differentiated optical services model for WDM networks

This article addresses the issues of scalable end-to-end QoS in metropolitan DWDM networks serving as transit networks for IP access networks. DWDM offering a few wavelengths has been deployed in the past in backbone networks to upgrade point-to-point transmission where sharing is based on coarse granularity. This type of DWDM backbone network, offering a few light-paths, provides no support for QoS services traversing the network. As DWDM networks with larger numbers of wavelengths penetrate the data-centric metro environment, specific IP service requirements such as priority restoration, scalability, dynamic provisioning of capacity and routes, and support for coarse-grain QoS capabilities will have to be addressed in the optical domain in order to achieve end-to-end QoS over a DWDM network. We propose a QoS service model in the optical domain called differentiated optical services (DoS) based on a set of optical parameters that captures the quality and reliability of the optical lightpath     

Ad Hoc网络协议栈通用要求研究

Ad Hoc网络是由一组带有无线收发装置的移动节点组成的一个多跳的临时性的自治系统。Ad Hoc网络与有线网络相比有很多特殊点，会导致传统的网络协议栈在Ad Hoc下不能有效使用。解决的办法是使Ad Hoc网络的网络协议栈满足比传统协议栈更高的要求：物理层要能实现分布式多点发起的同步，媒体访问控制（MAC）层要能管理多个分布站点随机的收发行为，网络层要能高效地管理分布式的路由协议，传输层要针对各种不同的业务进行优化。     

QoS Based Survivable Logical Topology Design in WDM Optical Networks

The need to establish wavelength-routed connections in a service differentiated manner is becoming increasingly important. In the backbone network, support of quality of service (QoS) capabilities at the lightpath level will have to be addressed in the optical domain. Providing a service differentiated connection on an arbitrary virtual topology which does not support any differentiated services will lead to the misuse of network resources. We address the virtual topology design and routing problem, where we minimize congestion in the network. In our work, the service differentiating parameter is bit error rate (BER) in the optical domain. We present a mixed integer linear programming (MILP) formulation for the above problem. We also propose a heuristic based approach to minimize the congestion in the network while satisfying the QoS constraints. These QoS constraints in our case are the differing BER requirements for each connection between each (source, destination) pair. We then present different methods of providing survivability for the virtual topology and compare the performance of these methods.     

A cost-based scheduling algorithm for differentiated service on WDM optical networks

One of the important issues in the design of future generation of high-speed networks is to provide differentiated services to different types of traffic with various time constraints. We propose an adaptive scheme to manage message transmission in single-hop passive-star coupler based wavelength-division multiplexing (WDM) optical networks. This study suggests that when scheduling message transmission in WDM networks a differentiated service should be considered in order to meet the time constraint to transmission of real-time messages while non real-time messages are being served so that the overall performance of the network could be improved.