一个双重优化的IP-DiffServ定量QoS管理实现机制*

提出了IP-DiffServ 定量QoS 实现机制, 它通过在网络层实施业务量工程实现了业务类选择路由的优化, 通过在业务层实施业务计划实现了用户业务选择业务类的优化。它不但可以在DiffServ 机制下给用户业务应用提供定量QoS 保证, 而且可以提高网络资源的使用效率以及提高用户业务和选择路由的性能价格比。实验结果很好地证明了该机制的优点。     

一个优化的IP-DiffServ实时记费管理机制

提出了一个优化的IP-DiffServ实时记费管理机制。在SLA协商时和某个业务类满负荷时,该机制通过对用户业务和用户业务应用实施业务计划,为它们定义最优化的业务类。通过闲置价格、使用价格和拥塞价格的多价格体系,对用户业务进行基于使用量的实时计费。它不但可以提高网络的QoS保证能力、提高网络的抗拥塞能力以及维持用户业务价格稳定,而且可以提高网络提供业务的性能价格比。实验结果很好验证了该机制的优点。     

QoS-TEOS: QoS Guaranteed Throughput-Efficiency Optimal Distributed Scheduling in WiMAX Mesh Networks

WiMAX distributed scheduling can be modeled as two procedures: three-way handshaking procedure and data subframe scheduling procedure. Due to manipulating data transmission directly, data subframe scheduling has a closer relationship with user Quality of Service (QoS) satisfaction, and has more severe impact on network performance, compared with handshaking procedure. A QoS guaranteed Throughput-Efficiency Optimal distributed data subframe Scheduling scheme, named as QoS-TEOS, is proposed. QoS-TEOS achieves QoS guarantee through modeling services into different ranks and assigning them with corresponding priorities. A service with higher priority is scheduled ahead of that with lower priority and offered with high QoS quality. Same kinds of services that request similar QoS quality are classified into one service set. Different service sets are scheduled with different strategies. QoS-TEOS promotes network performance through improving network throughput and efficiency. Theoretical analysis shows that the scheduled data transmission should balance data generation rate from upper layer and transmission rate of physical layer, to avoid network throughput and efficiency declining. Simulation results show that QoS-TEOS works excellently to achieve throughput-efficiency optimization and guarantee a high QoS.     

一种基于多Agent服务的网络体系结构

本文从 Ａ Ｔ Ｍ 模型出发,介绍了一种基于多 Ａｇｅｎｔ服务的网络体系结构。本结构在硬软件方面提供通信服务、链接许可控制及信令服务等功能;支持以用户为中心的 Ｑｏ Ｓ 规程,允许多 Ａｇｅｎｔ 满足终端用户的各种服务请求。本结构之原型模拟系统经运行后,初步实现了内部带宽存储等机制,有效地满足了用户的 Ｑｏ Ｓ需求。     

一种基于模糊塔的QoS单播路由选择算法

综合考虑用户服务质量QoS需求和网络提供方收益的单播路由算法．给定用户请求类别和收费原则，通过建立网络提供方收益模型来确定针对每一类请求的概率收益．在此基础上，利用模糊塔，求出两网络节点之间既满足用户服务质量需求又试图最大化网络提供方概率收益的路由。仿真结果表明，算法是可行的和有效的。     

User-perceived quality of service in wireless data networks

For so long, the term quality of service (QoS) has been a pursuit area for network engineers trying to dimension wireless networks to run in the most efficient way possible. Of late, there has been a trend reversal, looking at the user perceptions of the network performance to decide where dimensioning can have the greatest impact. This paper demonstrates the importance of defining the concept of user-perceived QoS and linking this to specific wireless data network parameters for some anticipated valuable applications. It has been shown that a quantitative rating can be obtained for a variety of important factors in the assessment of service quality, and mapped to specific values of multiple network parameters. We found QoS to be application-specific, where various applications require different levels of network performance to satisfy users. The role of physical location was also examined, investigating the influence of being indoors versus outdoors on the user perception of QoS.     

一个提高WiMax服务质量的带宽分配调度算法研究

随着接入网络作为连接用户终端与核心网络的纽带的倍受关注,用户越来越关注数据传输的QoS(服务质量)问题。在IEEE802.16协议的MAC层定义了比较完善的QoS机制。但QoS机制中的核心问题,带宽调度算法,协议没有作出明确的阐述和定义。该文在已有典型算法基础上,吸收、采纳了已有算法中适合于IEEE802.16协议的带宽调度的方法,并结合IEEE802.16协议关于QoS的定义,提出了一个针对IEEE802.16协议的PMP(点对多点)模式下集中式的带宽分配调度算法。并在NS2模拟环境下对算法进行了测试。     

The relationship between quality of service perceived and delivered in mobile Internet communications

Today mobile network operators offer a wide variety of mobile Internet services to their customers including mobile email, banking, and news services. The acceptance of these services is heavily based on quality of service (QoS) experienced by the user. So far the discussion of QoS has been very network centric and the key to user satisfaction has been the network performance. In this paper we analyze the relationship between QoS perceived by the customer and network performance offered by the service provider. We conduct a lab experiment where network performance variables were controlled. Statistical analysis of the results indicates that there is no 1:1 correspondence or even truly linear relationship between network performance and perceived QoS as recommended by the International Telecommunications Union-Telecommunication (ITU-T). Instead the relationship varied from application to application. We examine several usability factors as potential reasons behind this phenomenon and make suggestions for future research.     

一种基于QoS的Internet服务管理体系结构

服务定位协议(SLP)是IETF提出的基于IP网络的服务定位标准。而这一标准并没有考虑对QoS的支持。未来的互联网络是一个具有QoS保证的网络。服务发现仅仅是Internet服务管理中的一个方面，发现服务不是最终目的，最终目的是为了使用这一服务。在对SLP体系结构、下一代互联网QoS服务管理及相关技术充分研究的基础上，提出了一种新奇的基于QoS的Internet服务管理体系结构模型。为使在服务表示与发现层支持QoS，对SLP定位协议进行了一些扩充。对服务定位协议扩充后，当用户代理在向服务代理发布请求时，可以在请求消息中绑定QoS对象参数，一旦服务代理接收到这一消息，就可以利用这些QoS参数与域管理器进行协商，协商结果可通过服务代理反馈给用户代理。这样不仅减小了网络开销，而且降低了传统的用户代理与域管理器协商的次数，在服务发现的同时用户代理还可以直接获得该服务的QoS信息。     

Service level agreements (SLAs) parameter negotiation between heterogeneous 4G wireless network operators

We are currently witnessing a growing interest of network operators to migrate their existing 2G/3G networks to 4G technologies such as long-term evolution (LTE) to enhance the user experience and service opportunities in terms of providing multi-megabit bandwidth, more efficient use of radio networks, latency reduction, and improved mobility. Along with this, there is a strong deployment of packet data networks such as those based on IEEE 802.11 and 802.16 standards. Mobile devices are having increased capabilities to access many of these wireless networks types at the same time. Reinforcing quality of service (QoS) in 4G wireless networks will be a major challenge because of varying bit rates, channel characteristics, bandwidth allocation and global roaming support among heterogeneous wireless networks. As a mobile user moves across access networks, to the issue of mapping resource reservations between different networks to maintain QoS behavior becomes crucial. To support global roaming and interoperability across heterogeneous wireless networks, it is important for wireless network operators to negotiate service level agreement (SLA) contracts relevant to the QoS requirements. Wireless IP traffic modeling (in terms of providing assured QoS) is still immature because the majority of the existing work is merely based on the characterization of wireless IP traffic without investigating the behavior of queueing systems for such traffic. To overcome such limitations, we investigate SLA parameter negotiation among heterogeneous wireless network operators by focusing on traffic engineering and QoS together for 4G wireless networks. We present a novel mechanism that achieves service continuity through SLA parameter negotiation by using a translation matrix, which maps QoS parameters between different access networks. The SLA matrix composition is modeled analytically based on the G/M/1 queueing system. We evaluate the model using two different scheduling schemes and we derive closed form expressions for different QoS parameters for performance metrics such as packet delay and packet loss rate. We also develop a discrete event simulator and conduct a series of simulation experiments in order to understand the QoS behavior of corresponding traffic classes.     

Multi-robot navigation based QoS routing in self-organizing networks

The technical development drives the future networks to become large-scale, heterogeneous, and dynamic. Bio-inspired networking can help reduce the time-space complexity of the complex network. Due to the good features such as self-organization and self-management, self-organizing network (SON) will most probably be a priority choice for the next generation network. In this paper, a swarm intelligence based Quality of Service (QoS) routing protocol is proposed for SON. The inaccurate routing and QoS information is described with fuzzy mathematics whilst the utilities of both the user and the network service provider are considered by applying game theory. Based on the multi-robot navigation algorithm, the protocol is able to search a routing path which can satisfy the user QoS requirements and achieve the Pareto optimal utilities of the user and the network service provider under Nash equilibrium. The proposed protocol is implemented and evaluated by extensive simulation experiments. The results show that it beats both other swarm intelligence based routing protocols and the traditional Dijkstra algorithm based routing protocol. The searched routing paths support the win–win effect for both the user and the network service provider.     

Adaptive power allocation with quality-of-service guarantee in cognitive radio networks

This paper proposes a novel power control policy for a cognitive radio network as an effort to maximize throughput under the average interference power constraint. The underlined policy ensures delay-related quality of service (QoS) requirements with reduced interference to the primary user. In this work we also take into account the peak and average transmit power constraints for the secondary user. An optimization problem associated with the power control policy is formulated based on a cross-layer framework, where the queue on data link layer is serviced by the power control policy at the physical layer. A recursive algorithm under the power constraints is developed to solve for the optimal solution. It is shown that the reduction of average interference to the primary user is related closely to the QoS requirements. The analysis derives the average interference power limits to the primary user in fading channels with guaranteed QoS requirements for the secondary user. The numerical results show the effectiveness of the proposed power control policy.     

User-input driven QoS management in ad hoc networks

Though the network quality-of-service (QoS) metrics are defined in terms of technical parameters (e.g., delay, jitter, bandwidth), they are rather subjective when it comes to the end user. Oftentimes, the end user finds it difficult to express his desired QoS in such technical parameters, though he has a fair idea of what QoS he desires. In this paper, we show how translation functions can be devised and used to translate the user inputs to networking parameters that are used by various layers of the protocol stack. In particular, we consider an ad hoc network and show an interface design that uses translation functions to map user supplied inputs to parameters at the medium access control (MAC) and routing layers. These parameters, in turn, choose the right strategies that particular layer functionality can adopt, such that the QoS desired by the user is achieved. We also compute the associated costs due to the different strategies adopted. We implement the interface on ns-2 and conduct simulation experiments with randomly scattered IEEE 802.11 enabled nodes. Results show the functionality of the interface and demonstrate how delay, throughput, and network lifetime are affected when the end user seeks different levels of QoS.     

IP QoS体系结构

通过对目前正在研究的四类IP QoS协议（RSVP,DiffServ,MPLS,SBM）的详细分析比较发现：虽然它们都能够提供对QoS的支持,但都不能单独成为大规模网络环境下的QoS解决方案,只有对它们的综合应用才能真正实现广域环境下的数据流可预测性传输。以此为基础,给出了大规模网络系统中的IP QoS体系结构。     

面向用户需求的动态QoS服务选择方法研究

高效、准确地为用户选择满足其需求的软件服务一直是近年来的研究热点。服务质量（Quality of Service,QoS）是衡量软件服务性能的关键指标之一,考虑到同一服务在不同网络环境下QoS值的动态性,提出一种面向用户需求的动态QoS服务选择方法,简称URDQ方法。URDQ方法采用区间数的形式记录动态环境下候选服务的属性值范围,并基于用户需求对候选服务进行初步过滤;通过区间数模型对候选服务属性区间和用户需求区间进行相对优势度计算,将属性区间数转化为易于计算的实数;使用Skyline方法对候选服务集进行过滤,减小搜索空间;根据熵权法得到的客观权重并结合用户给定的主观权重,使用TOPSIS方法对Skyline服务集进行排序。仿真实验和对比实验验证了URDQ方法在动态网络环境下的可行性和有效性。     

Providing service differentiation in pure IP-based networks

The lack of an effective cooperation between the data, control and management plane of QoS routing solutions presented so far, prevents the implementation of service differentiation in the context of pure IP-based networks. Most of paths calculation proposals performed by the control plane are unaware of service characteristics of each flow. Scalable data plane QoS proposals ignore the issue about selecting the best paths to route the traffic. Proposed management plane schemes do not perform the network state maintenance and service level monitoring. Multi-service routing is a flow-based forwarding protocol that implements the service differentiation in pure IP-based networks, using a straight cooperation between data, control and management plane. This cooperation is accomplished by a data plane supporting the DiffServ model and performs route selection based on flows service class, which is exploited by the management plane to carry out the network state maintenance, and performance monitoring by using the RTCP protocol, to provide service metrics to control plane for route calculation. Simulation experiments show better performance results achieved by Multi-service routing compared to those obtained by traditional link state protocol with the DiffServ model and QoS routing in heavy loaded network scenarios of mixed traffic having different service requirements.     

用于区分服务的MPEG-4多媒体内容分类机制

描述了一种用于区分服务的MPEG-4多媒体内容分类机制。它通过向MPEG-4系统结构中加入一个新的媒体QoS分类层,把具有相近QoS性能需求的MPEG-4 AVO分为一类并映射到区分服务中。新的媒体QoS分类层采用一种对于应用层和网络层均透明的分类算法对MPEG-4 AVO进行分类。给出了该算法的结构和设计原则。     

基于适配层融合网络系统平台

异构网络融合已成为信息通信技术发展的必然趋势,是现代服务业发展的基础。为了解决网络融合与多接入、多终端需求的一致性问题,提出了一种基于适配层的网络融合架构,构建以用户为中心的支持多接入、多终端的异构网络平台来支撑现代服务业的应用,并且提出了相应融合系统平台的逻辑框架及其系统的物理拓扑结构。该系统架构在现代服务业行业中的应用结果表明,该架构能够有效地解决跨网络、跨终端的系统融合,从而保证网络的QoS性能并提升用户体验。     

SoMR: A scalable distributed QoS multicast routing protocol

Many Internet multicast applications such as teleconferencing and remote diagnosis have Quality-of-Service (QoS) requirements. The requirements can be additive (end-to-end delay), multiplicative (loss rate), or of a bottleneck nature (bandwidth). Given such diverse requirements, it is a challenging task to build QoS-constrained multicast trees in a large network where no global network state is available. This paper proposes a scalable QoS multicast routing protocol (SoMR) that supports all three QoS requirement types. SoMR is scalable due to small communication overhead. It achieves favorable tradeoff between routing performance and routing overhead by carefully selecting the network sub-graph in which it searches for a path that can support the QoS requirements. The scope of search is automatically tuned based on the current network conditions. An early-warning mechanism helps detect and route around the long-delay paths in the network. The operations of SoMR are completely decentralized. They rely only on the local state stored at each router.     

基于模糊积分和博弈论的QoS组播路由机制

下一代互联网NGI(next generation Intemet)需要提供服务质量QoS(quality of service)路由能力.由于NGI网络状态难以精确测量与表达,因此,QoS路由基于的信息应该是模糊的.随着网络运营的渐趋商业化,付费上网要求实现QoS计费,而网络提供方与用户的利益冲突要求实现效用双赢.设计了一种基于模糊积分和博弈论的QoS组播路由机制.该机制由边评判、博弈分析和组播路由树建立算法组成,基于模糊积分和适合隶属度函数对边进行模糊综合评判,通过博弈分析确定网络提供方与用户在边上的效用能否达到Nash均衡,通过组播路由树建立算法使得在建立的组播路由树上不仅用户QoS要求得到满足,而且网络提供方效用与用户效用达到或接近Nash均衡下的Pareto最优.仿真结果表明,与QoSMIC等机制相比,该机制具有较好的性能.