Differentiated Wavelength Assignment with QoS Recovery for DWDM Next Generation Internet Backbone Networks

This paper describes a differentiated wavelength assignment strategy for the appropriate allocation of wavelengths on wavelength-routed quality of service (QoS) routes with differentiated QoS class and recovery capabilities. The paper is based on the differentiated MPS services (DMS) model as a framework for optical bandwidth management and the real time provisioning of optical channels in re-configurable transport networks. MPS stands for multi protocol lambda switching which is a functional part of GMPLS (generalized MPLS). We discuss here a QoS recovery scheme at the optical layer, at the MPS layer, and at the IP layer, as related to QoS failure caused by device failures or attack-induced faults in dense-wavelength division multiplexing (DWDM) transport networks. According to the QoS characteristics of wavelength in optical links and the type of used optical cross-connect (OXC) nodes, a differentiated wavelength assignment strategy that considers QoS recovery capability is also described. We point out important problems that should be resolved in the DMS model for optical QoS routing with differentiated wavelength assignment.     

QoS Recovery Schemes Based on Differentiated MPLS Services in All-Optical Transport Next Generation Internet

The Internet is evolving from best-effort service toward an integrated or differentiated service framework with quality-of-service (QoS) assurances that are required for new multimedia service applications. Given this increasing demand for high bandwidth Internet with QoS assurances in the coming years, an IP/MPLS-based control plane combined with a wavelength-routed dense wavelength division multiplexing (DWDM) optical network is seen as a very promising approach for the realization of future re-configurable transport networks. Fault and attack survivability issues concerning physical security in a DWDM all-optical transport network (AOTN) require a new approach taking into consideration AOTN physical characteristics. Furthermore, unlike in electronic networks that regenerate signals at every node, attack detection and isolation schemes may not have access to the overhead bits used to transport supervisory information between regenerators or switching sites to perform their functions. This paper presents an analysis of attack and protection problems in an AOTN. Considering this, we propose a framework for QoS guarantees based on the differentiated MPLS service (DMS) model and QoS recovery schemes against QoS degradation caused by devices failures or attack-induced faults in an AOTN. We also suggest how to integrate our attack management model into the NISTs simulator—modeling, evaluation and research of lightwave networks (MERLiN).     

一种稀疏分光配置约束下的WDM网络多播RWA算法

在波长路由WDM网络中,波长路由和波长分配是RWA算法提高光网络阻塞性能的两个重要阶段和关键技术。文章针对现有的稀疏分光配置约束下的光网络多播RWA算法复杂度高、代价高的问题,提出了一种新的稀疏分光器配置的RWA多播算法。该算法摒弃传统RWA算法在波长路由阶段就考虑稀疏分光约束能力的惯性思维,论文首次提出在波长分配阶段,才通过多播长转换器实现满足稀疏分光约束条件的分光能力传递。仿真结果表明,所提算法在平均代价和所需波长数目方面都获得了较优的性能。     

Optical-LSP Establishment and a QoS Maintenance Scheme Based on Differentiated Optical QoS Classes in OVPNs

A virtual private network (VPN) over Internet has the benefit of being cost-effective and flexible. However, it has difficulties providing sufficient QoS and adequate transmission capacity for high bandwidth services. Given the increasing demand for high bandwidth Internet and the demand for QoS assurances in a VPN over Internet, IP/generalized multi-protocol label switching (GMPLS) based on a control plane combined with a high-bandwidth, dense-wavelength division multiplexing (DWDM) optical network is seen as a very favorable approach for realizing the future optical VPN (OVPN) over IP/GMPLS over DWDM. Within this architecture, providing QoS guaranteed multimedia services with a differentiated QoS guaranteed protocol framework with QoS recovery is one of the key issues to implement. Therefore, we suggest in this paper optical-label switched path (O-LSP) establishment and its QoS maintenance scheme based on differentiated optical QoS-service (DOQoS) classes. They are the key components for this DOQoS framework in assuring end-to-end QoS in an OVPN over IP/GMPLS over DWDM architecture.     

下一代VoIP网络的QoS保证

如何实现下一代VoIP网络的QoS保证是影响未来网络发展的重要问题.本文结合下一代VoIP网络的体系结构和QoS需求,介绍了3GPP和PacketCable等标准化组织在这一领域的研究成果,并进一步讨论分析了MSF在更高层面构筑的通用的体系结构框架.     

QoS Routing Algorithm with Multi-Dimensions for Overlay Networks

Overlay networks have emerged as a useful approach to providing a general framework for new applications and services that are to be implemented without significantly changing the IP-layer network infrastructure. Overlay routing has been used as an alternative to the default best effort Internet routing for the absence of end-to-end Quality of Service （QoS）. While the former has recently been in- vestigated, the conflict of QoS restraints and resource optimization remains unsolved. Re- cent studies have shown that overlay paths can give better latency, loss rate and TCP throu- ghput. In this paper, a multi-dimensional QoS objective model based on the analysis of mul- tiple QoS constraints has been presented, and a routing algorithm to optimise the overlay re- source of its nodes and links is then proposed. In fact, the algorithm obtained multiple QoS values using probability theory to achieve the ro- uting according to the multi-dimensional QoS objective vector of the QoS objective model. Simulation results reveals that the algorithm works better than other existing algorithms in balancing the network resources, and applications with stringent QoS requirements could be run.     

下一代光网络中光路的快速建立

文章针对下一代光网络中光路快速建立的问题,介绍了IP-over-optical的网络体系结构,并在此基础上介绍了动态RWA问题和综合解决RWA问题的动态和半动态寻路算法,讨论了这两种算法的容错性能。     

IP over DWDM光互联网技术

对基于ＩＰ ｏｖｅｒ ＤＷＤＭ的新型数据网络体系结构－－光互联网络技术进行了探讨。在分析了三种构造未来信息网络解决方案的基础上,着重对基于ＩＰ ｏｖｅｒ ＤＷＤＭ的光互联网络的关键技术、光互联网的网络结构等内容进行了研究。     

一种在MPLS网络中支持QoS的流量工程算法

该文提出了一种改善QoS的队列调谐算法(QueueTuningAlgorithm:QTA),该算法应用于多协议标签交换(MPLS)流量工程。该算法通过把不同类别的业务,如传统的尽力而为(Best-Effort)业务和具有QoS需求的业务,映射到不同队列,然后根据链路的状况以及业务的QoS需求来进行队列调谐。QTA在实现负载均衡的同时又支持业务流的QoS,优化网络资源的利用。仿真表明该算法在MPLS网络中运行良好。     

宽带CDMA IP网中实现区分服务的QoS结构

3G CDMA网提供高速无线IP服务,其业务主要包括数据、语音互式多媒体。为了能保证这些异构业务的QoS,并提供业务区分,将有线IP网的分区服务（DIFFSERV）QoS模型引入3G CDMA网络。针对无线网络的终端移动性、高丢失率、更低的网络带宽等特点,对原有的DIFFSERV结构进行了修改,给出了基于DIFFSERV的无线QoS结构,并简单描述了实现协议。还给出了有效带宽的录入控制策略和资源预留策略来实现QoS。通过仿真,研究了各种策略的性能。     

下一代Internet的QoS和移动性及其构架

下一代Internet应该能够支持具有不同服务质量要求的各种业务,不管是固定用户还是移动用户。文中所介绍的下一代Internet的QoS和移动性及其构架融合了各种QoS结构模型和移动协议以及基于一定预定义标准（QoS参数）之间的不同无线和有线接入技术。     

基于QoS的下一代网络的研究

随着下一代网络的发展,QoS保障成为下一代网络的一个重要课题.下一代网络的核心是软交换网络,而IP网将是软交换网络的承载网,所以,保障下一代网络的QoS可以从IP网、接入网、接入设备分别入手.文章首先在分析了下一代网络的新特征和一般模型的基础上,重点论述了作为下一代网络承载网的IP网的端到端QoS的保障方法:MPLS与IntServ和DiffServ相结合保障端到端QoS的技术,IntServ与DiffServ结合保障端到端QoS的技术.最后文章对接入网(FTTB LAN接入时)和接入设备(媒体网关,IAD)如何提供QoS也进行了综述.     

Admission Control Algorithms for Revenue Optimization with QoS Guarantees in Mobile Wireless Networks

We propose and analyze call admission control algorithms integrated with pricing for revenue optimization with QoS guarantees to serve multiple service classes in mobile wireless networks. Traditional admission control algorithms make acceptance decisions for new and handoff calls to satisfy certain QoS constraints such as the dropping probability of handoff calls and the blocking probability of new calls being lower than a pre-specified threshold. We analyze a class of partitioning and threshold-based admission control algorithms that make acceptance/rejection decisions not only to satisfy QoS requirements but also to optimize the revenue of the system by taking prices and arrival/departure information of service calls into account. We show that for a “charge-by-time” pricing scheme, there exist optimal resource allocation settings under which the partitioning and threshold-based admission control algorithms would produce the maximum revenue obtainable by the system without sacrificing QoS requirements. Further, we develop a new hybrid admission control algorithm which outperforms both partitioning and threshold-based admission control algorithms over a wide range of input parameters characterizing the operating environment and service workload conditions. Methods for utilizing of the analysis results for realtime admission control for revenue optimization with QoS guarantees are described with numerical data given to demonstrate the applicability.     

Layered Video and Differentiated Coding for Adaptive QoS in Mixed Wired-Satellite Networks

Mobile networks are becoming nothing but a way to allow ubiquitous access to multimedia services. To allow efficient use of resources, new systems provide flexible bandwidth and different error protection techniques to match channel behavior. As the backbone network is increasingly becoming based on packet techniques and in particular on IP and related transport protocols, end to end service quality must be analyzed considering both the fixed and the mobile part. Source scalability may help in coping with a mixed and heterogeneous environment. In this work we present some results of a transmission chain comprising a scalable MPEG-2 coder, an IP network and a radio access exploiting the availability of satellites. It is shown that for a given target rate, differentiated coding can be exploited to achieve decodability and good quality at a channel SNR much lower that single layer streams. This revised version was published online in July 2006 with corrections to the Cover Date.     

可生存光网络中的不同QoS策略

随着光网络技术的不断发展,网络的生存性及其QoS问题越来越受到关注.文章围绕可生存光网络中的不同QoS策略这一问题,首先介绍了可生存光网络及其QoS参数的概念,解释了为什么如今要考虑可生存光网络中的不同QoS策略.接着以传统光网络生存性方法的一般分类图为依据,从原理、性能等方面归纳比较了以往各种生存性方法,并分析了各自的优缺点.最后根据考虑可生存性光网络中QoS参数的不同,具体描述了用来支持不同业务的各种光网络生存性方法.     

A Novel Algorithm Supporting QoS for Traffic Engineering in MPLS Networks

1　Introduction　AstheQoSrequirementofserviceclasseshaschangeddramaticallyduringthepastyears,thesingle classbesteffortarchitecturecurrentlyusedintheinternetcan tmeettheincreasingneedofdifferenttrafficswithdiffer entQoSrequirements .Asaresult ,themanagementandcontrolofTrafficEngineering (TE)becomesmoreimportantinhigh speednetworksforserviceproviders.AccordingtoInternetEngineeringTaskForce ,TEisanaspectofnetworkengineeringconcernedwiththeissueofnetworkperformanceoptimization[1] .Thenewlye …     

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.     

QoS Guarantees in Heterogeneous Systems Consisting of IP Core Networks with Satellite Access

This paper aims at investigating the issue of differentiated QoS provision to services over a heterogeneous terrestrial-satellite infrastructure. In particular, the implementation of a dynamic mapping of the main service classes offered by IP IntServ and DiffServ models over satellite bearer services is investigated.Objective of the research is to enable mobile subscribers to access broadband services offered within a fixed IP core network, through satellite links. This has to be performed while still guaranteeing the same Quality of Service (QoS) offered by the IP IntServ and DiffServ models over the terrestrial segment. In such an environment, the considered traffics derive from multimedia applications and are characterised by real-time and non-real-time constraints as well as variable (VBR) and constant (CBR) bit-rate profiles.     

支持下一代无线宽带应用自适应QoS模型的研究

作为真正完整的下一代网络 ( NGN,Next Generation Network)解决方案 ,NGN需要在固定通信领域和移动通信领域都能够支持综合多媒体特性。NGN中的新一代移动通信网承载在开放式、层次化结构的分组交换网络之上 ,能够为用户提供端到端的 Qo S解决方案。本文分析了下一代移动通信系统中多媒体宽带应用的 Qo S问题 ,从无线通信系统的多层次结构出发 ,建立了业务流的 Qo S指标评判体系 ,为下一代网络中的无线宽带应用提供了一种自适应Qo S控制模型     

A Framework for Seamless Roaming Across Heterogeneous Next Generation Wireless Networks

In the future, wireless and mobile users will have increased demands for seamless roaming across different types of wireless networks, quality of service guarantees and support of different types of services. This awareness has led to research activities directed towards inter-system and global roaming and can be noticed in the numerous products like multimode handsets, inter-working gateways and some ongoing standards and research work on signaling protocols for inter-system roaming. This article proposes a global mobility management framework. The framework is like an overlay network comprising of Inter-System Interface Control Units IICU to support inter-network communication and control for Location Management. The protocols and functions of this framework will be distributed and exist partly within the wireless networks and partly within the core-network. A hierarchy introduced among the IICUs will accommodate for the varying mobility coverage required by the mobile user. The IICU may be configured to perform various functions depending on its placement in the hierarchy of the framework. This approach aims to optimize across call set up delays, signaling traffic, database processing, handoff facilitation for seamless roaming and QoS mapping and negotiations as the user moves across different wireless networks. It avoids centralized database dependency with its associated single-point bottleneck and failures. We restrict our analysis of the framework to a 2-network and a 3-network roaming scenario. The presentation has been further restricted to cost and delay analysis of the location update and call delivery procedures. We have taken into account the signalling requirements when the mobile user roams across networks with and without an active call. Nirmala Shenoy is Associate Professor at the Information Technology department at RIT. She has several years of teaching and research experience while working in Germany, Singapore and Australia before she moved to USA. She is an avid researcher in the wireless networks area and has technically led several wireless network projects to success. She holds a Ph.D. in computer science from the University of Bremen, Germany, Masters in Applied Electronics and Bachelors in Electronics and Telecommunications Engineering both from Madras University in India. Professor Shenoy is interested in research in the area mobility management and modeling for wireless networks, Quality of service in wireless networks and the Internet.