定向天线卫星网络空间重用的带宽预留算法

基于无线网络中设计提供服务质量(quality of service,QoS)的路由协议是一项具有挑战性的工作,提出无线卫星网络中基于定向天线的服务质量保证的空间重用的带宽预留算法。卫星网络中许多音/视频会议、远程教育等重要应用,需要服务质量保证。无线网络中的定向天线技术提供了显著增加空间重用性的能力,提高无线网络中的数据传输效率。研究使用定向天线的无线卫星网络中基于时分多址的带宽预留算法,该算法给不同方向的地面终端分配相同时隙来提高带宽资源的空间重用性,提高通信效率。通过模拟实验分析研究证明,该算法在服务质量调用成功率、吞吐量和延迟方面有比较好的性能。     

QoS based multicast routing algorithms for real time applications

In recent years, there has been a lot of interest in providing real-time multimedia services like digital audio and video over packet-switched networks such as Internet and ATM. These services require certain quality of service (QoS) from the network. The routing algorithm should take QoS factor for an application into account while selecting the most suitable route for the application. In this paper, we introduce a new routing metric and use it with two different heuristics to compute the multicast tree for guaranteed QoS applications that need firm end-to-end delay bound. We then compare the performance of our algorithms with the other proposed QoS-based routing algorithms. Simulations were run over a number of random networks to measure the performance of different algorithms. We studied routing algorithms along with resource reservation and admission control to measure the call throughput over a number of random networks. Simulation results show that our algorithms give a much better performance in terms of call throughput over other proposed schemes.     

Introducing QoS awareness in distributed programming: QTcl

A number of distributed applications require communication services with quality of service (QoS) guarantees. Building global‐scale distributed systems with predictable properties is one of the great challenges for computer systems engineering in the new century. Work undertaken within the Internet Engineering Task Force has led to the definition of novel architectural models for the Internet with QoS support. According to these models, the network has to be appropriately configured in order to provide applications with the required performance guarantees. In next‐generation networks, enabling applications to interact with the underlying QoS services is of primary importance. Hence, several special‐purpose application programming interfaces (APIs) have been defined to let applications negotiate QoS parameters across QoS‐capable networks. However, so far, none of these APIs are available in different operating environments. We believe that such features should be embedded in programming environments for distributed applications. In this work we present how we included QoS control features in Tcl, a programming language that has been widely adopted for the development of distributed multimedia applications. Our work has led to the implementation of QTcl, an extended Tcl interpreter that provides programmers with a new set of primitives, in full compliance with the standard SCRAPI programming interface for the RSVP protocol. QTcl in highly portable, in that it enables standard QoS negotiation to be performed in a seamless fashion on the most common operating systems. Copyright © 2003 John Wiley & Sons, Ltd.     

Bandwidth Aggregation-Aware Dynamic QoS Negotiation for Real-Time Video Streaming in Next-Generation Wireless Networks

In next generation wireless networks, Internet service providers (ISPs) are expected to offer services through several wireless technologies (e.g., WLAN, 3G, WiFi, and WiMAX). Thus, mobile computers equipped with multiple interfaces will be able to maintain simultaneous connections with different networks and increase their data communication rates by aggregating the bandwidth available at these networks. To guarantee quality-of-service (QoS) for these applications, this paper proposes a dynamic QoS negotiation scheme that allows users to dynamically negotiate the service levels required for their traffic and to reach them through one or more wireless interfaces. Such bandwidth aggregation (BAG) scheme implies transmission of data belonging to a single application via multiple paths with different characteristics, which may result in an out-of-order delivery of data packets to the receiver and introduce additional delays for packets reordering. The proposed QoS negotiation system aims to ensure the continuity of QoS perceived by mobile users while they are on the move between different access points, and also, a fair use of the network resources. The performance of the proposed dynamic QoS negotiation system is investigated and compared against other schemes. The obtained results demonstrate the outstanding performance of the proposed scheme as it enhances the scalability of the system and minimizes the reordering delay and the associated packet loss rate.     

混合网络模型中的QoS路由算法

QoS路由为具有QoS要求的应用寻找满足条件的网络路径,同时优化网络的资源利用率.IntServ/DiffServ混合网络模型很好的结合了IntServ网络每一流的处理能力和DiffServ网络良好的可扩展性的优点.本文提出了一种在这种混合网络模型中提供带宽一延时保证服务的QoS路由算法,对于在网络中传送具有带宽一延时要求的应用服务是一个可行的解决方案.通过仿真实验,验证了算法的有效性.     

SUTIL – Network selection based on utility function and integer linear programming

This work presents SUTIL, a mechanism for network selection in the context of next generation networks (NGN). SUTIL selection mechanism prioritizes networks with higher relevance to the application and lower energy consumption and it enables full and seamless connectivity to mobile user devices and applications. Consequently, SUTIL contributes to realize the vision of ubiquitous computing, in which services, devices, and sensor-enriched environments interact anytime, anywhere to accomplish human designed tasks. The provided solution is based on utility function and integer linear programming and it aims at: (i) maximizing the user satisfaction while meeting application QoS and (ii) minimizing the energy consumption of devices when connecting to a target network. The solution is global since it considers for a given base station all devices that are simultaneously candidate for handoff. Simulation results showed the benefits of SUTIL usage in NGN environments.     

一种业务驱动的多媒体传感器网络路由算法

针对多媒体传感器网络承载业务（视频图像业务、音频业务以及数据业务）的差异性和不同业务对QoS的差异性,基于蚁群算法和混沌理论,抽象业务驱动的QoS路由模型,提出了一种业务驱动的路由算法SDR（Service-Driver Routing）。依据各类业务对QoS的差异性选择相应路由策略,达到充分利用网络资源、提高网络承载业务性能的目标。采用NS2对该算法进行实验仿真,实验结果表明,与其他路由算法相比,该算法可提供区分业务的QoS保障。     

Dynamic rerouting of guaranteed Quality-of-Service connections

To support the widespread demands for integrated services various solutions have been proposed to provide guaranteed Quality-of-Service (QoS) services in packetswitched networks. These solutions usually require fixed route selection and resource reservation on a per connection basis. The routing and reservation decisions, combined with load fluctuations, introduce the problems of network unavailability and loss of network management flexibility. We believe that these problems can be alleviated by transparently rerouting connections to properly balance the network load. In this paper, we present a solution that supportstransparent route modification ofguaranteed QoS connections during the life time of the connections. As the emphasis of this work is to support transparency we must ensure that during and after the rerouting, the QoS guarantees made to the client are preserved, and the interface instances at both the sender and receiver are unaltered. Our solution includes the mechanisms that support the transparent rerouting of connections, and a routing algorithm that is based on the traffic characteristics, the delay, and the jitter requirements of a connection. This routing algorithm can also use various administrative constraints and facilitate the reuse of resources currently reserved by the connection. To optimize the solution, additional mechanisms have been introduced to reduce the time needed to reroute a connection and to support rerouting of segments of a connection. The solution has been implemented in the context of the Tenet scheme and route changes can be observed and controlled by using the Simple Network Management Protocol (SNMPv 1). Simulation experiments and some initial measurements of the implementation demonstrate that such a scheme is useful, practical, and can be achieved with load overhead.     

Third party application control on quality of service in IP based multimedia networks

The paper investigates the capabilities for open access to resource management in convergent networks. Based on the analysis of policy and charging control functions in Internet Protocol Multimedia Subsystem (IMS), requirements for third party application control on quality of service (QoS) are identified. The functionality of Open Service Access (OSA) and Parlay X interfaces is evaluated for support of dynamic QoS control. An approach to design of OSA compliant application programming interfaces to QoS management in IMS networks is presented. The interface methods are mapped onto the messages of network control protocols such as Diameter and Session Initiation Protocol (SIP). The application view of authorized QoS resources for SIP session is modeled. Implementation issues concerning behavioral equivalence of the authorized QoS resources model and SIP session state model are discussed.     

数据中心网络路由研究进展

随着云计算的迅速发展,运营商对数据中心的需求与日俱增.作为数据中心网络的关键技术,路由负责在数据中心内部以及数据中心之间为流量选路,为不同服务质量要求的流量提供差异化的路由转发服务.当数据中心规模比较大时,由于应用不可预估的通信流量以及数据中心网络的拓扑特点,传统因特网路由方法不能提供令人满意的高吞吐率和资源利用率,网...     

一种基于DPSO的无线传感器网络QoS路由算法

针对无线传感器网络中不同业务对服务质量(QoS)的不同需求,提出一种基于离散粒子群优化(DPSO)的无线传感器网络QoS路由(DPSO-QR)算法。算法将路由建立过程抽象为多目标优化过程,以节点间通信的传播损耗、时延、带宽、丢包率为优化目标,利用DPSO算法实现多目标优化,为拥有不同QoS需求的网络业务提供满足其特有需求的优化路由。仿真实验表明:与SAR,EQR算法相比,DPSO-QR算法降低了网络平均端到端时延,减小了丢包率,延长了网络寿命。     

LEO卫星网QoS遗传算法路由协议

为了满足多媒体应用的QoS要求,卫星路由协议应该更有效地利用网络资源,提供更好的QoS保障。为此提出了一个基于遗传算法的LEO卫星网络QoS路由协议,称为遗传卫星路由协议（GSRP）。改进了新的操作函数,如适应度函数、终止函数,以及变异率和路由表。仿真结果表明,GSRP能够实现较少CBP和HBP的可靠的点对点时延约束,以及比传统的算法更有效的负载平衡。     

Ant-based routing for wireless multimedia sensor networks using multiple QoS metrics

In wireless sensor networks, most routing protocols consider energy savings as the main objective and assume data traffic with unconstrained delivery requirements to be a given. However, the introduction of video and imaging sensors unveils additional challenges. The transmission of video and imaging data requires both energy efficiency and QoS assurance (end-to-end delay and packet loss requirements), in order to ensure the efficient use of sensor resources as well as the integrity of the information collected. This paper presents a QoS routing model for Wireless Multimedia Sensor Networks (WMSN). Moreover, based on the traditional ant-based algorithm, an ant-based multi-QoS routing metric (AntSensNet) is proposed. The AntSensNet protocol builds a hierarchical structure on the network before choosing suitable paths to meet various QoS requirements from different kinds of traffic, thus maximizing network utilization, while improving its performance. In addition, AntSensNet is able to use a efficient multi-path video packet scheduling in order to get minimum video distortion transmission. Finally, extensive simulations are conducted to assess the effectiveness of this novel solution and a detailed discussion regarding the effects of different system parameters is provided. Compared to typical routing algorithms in sensor networks and the traditional ant-based algorithm, this new algorithm has better convergence and provides significantly better QoS for multiple types of services in wireless multimedia sensor networks.     

基于神经网络的动态路由选择算法

在分析了网络中基于QoS组播路由问题的基础上,文章给出了基于Hopfield神经网络的动态路由选择算法的模型。仿真研究表明该算法具有良好的分布特性和智能决策能力,此方案不仅保证了带宽、端到端延时和延时抖动,优化了路由树的代价,而且有效地控制了算法的复杂性,是一种快速动态组播路由算法,能实现全局网络资源利用的优化,容易扩展到大型网络中应用。     

宽带卫星网络边界路由技术研究

在中低轨道卫星星座中,利用星间链路组网是宽带卫星网络技术发展的一个主要方向。卫星网络中的边界路由主要解决卫星网络和地面网络之间在网络层的互操作性问题,实现网络层的互相融合,使端用户能够通过异构网络来透明地通信。在分析已有研究的基础上,结合地面网络使用的边界路由技术,给出了地面网络与卫星网络的互连模型,分析了具有星间链路的卫星网络中边界路由问题的实质,并介绍了一种基于BGP4协议的卫星网络边界路由机制,进而指出了后续的研究方向。     

Reconfiguration for service and self-healing in ATM networks based on virtual paths

This paper presents a reconfiguration scheme resulting in capacity efficiency and fast restoration by utilizing the inherent benefits of Virtual Paths in ATM networks. The unified optimization of bandwidth reconfiguration is addressed so that switched ATM networks can support both service and survivability from a common pool of network spare capacity at a given time. The spare capacity is composed of idle bandwidth and freed up bandwidth from the switch pairs which have a surplus bandwidth. Fast restoration can be achieved by using the pre-optimized network spare bandwidth and preplanned backup Virtual Paths based on the link and node disjoint path routing scheme. The overall operation of the proposed self-healing strategy can be consolidated into distributed fault management functions at ATM layer based on Virtual Paths. The scheme enables a logical Virtual Paths ring protection switching in ATM networks.     

AMRST: adaptive multicast routing protocol for satellite–terrestrial networks

Multicasting facilitates the distributing of multimedia information to an entire set of destinations simultaneously. However, the subsequent mass of Internet traffic usually increases the network congestion and degrades network utilization. The unexpected congestion together with limited network capacity might challenge the provision of multimedia services especially since multicast subscribers are widely scattered. The desired QoS of the ongoing services cannot be guaranteed. To address this challenge, in addition to installing new terrestrial broadband networks, another feasible solution would be to integrate now available broadcasting-oriented broadband satellite networks into the Internet backbone. This paper presents a novel adaptive multicast routing (AMRST) protocol to deliver reliable and adaptive multicast services to global subscribers, based on an integrated infrastructure, called a satellite–terrestrial network (ST network), which provides dynamic bandwidth allocation, flexible resource management and ubiquitous transmission. In the AMRST, a proposed virtual hierarchical routing tree was applied in constructing an efficient multicast tree. A routing decision model was proposed to determine routing path for the member requests. A “hierarchical membership maintenance” approach was designed to maintain the multicast membership. The scalability of the AMRST was further addressed. The AMRST not only kept the benefits of the traditional terrestrial multicast but also promoted the multicasting performance by employing the satellite broadcasting capability. The simulation results demonstrate that the AMRST performed excellently for the ST network.     

A reliable QoS aware routing protocol with slot assignment for mobile ad hoc networks

A mobile ad hoc network (MANET) is a collection of mobile hosts that form a temporary network on the fly without using any fixed infrastructure. Recently, the explosive growth in the use of real-time applications on mobile devices has resulted in new challenges to the design of protocols for MANETs. Chief among these challenges to enable real-time applications for MANETs is incorporating support for quality of service (QoS), such as bandwidth constraints. However, MANETs having a high ratio of topology change make routing especially unstable; making stability is an important challenge, especially for routing having a quality of service provision. In this paper, we propose a reliable multi-path QoS routing (RMQR) protocol with a slot assignment scheme. In this scheme, we examine the QoS routing problem associated with searching for a reliable multi-path (or uni-path) QoS route from a source node to a destination node in a MANET. This route must also satisfy certain bandwidth requirements. We determine the route expiration time between two connected mobile nodes using global positioning system (GPS). Then, two parameters, the route expiration time and the number of hops, are used to select a routing path with low latency and high stability. Simulation results show that the proposed RMQR protocol have some outstanding properties when compared with Lin's [Lin C-R. On-demand QoS routing in multihop mobile networks. In: Proceedings of the twentieth annual joint conference of the IEEE computer and communications societies (INFOCOM), vol. 3(22–26), 2001, p. 1735–44], Liao's [Liao W-H, Tseng Y-C, Wang S-L, Sheu J-P. A multi-path QoS routing protocol in a wireless mobile Ad Hoc network. Telecommunication Systems 2002;19(3–4):329–47], and Chen's [Chen Y-S, Tseng Y-C, Sheu J-P, Kuo P-H. An on-demand, link-state, multi-path QoS routing in a wireless mobile Ad-Hoc network. Computer Communications 204;27(1):27–40] protocols.     

Quality of Service Support in RPL Networks: Standing State and Future Prospects

The development of IP-based Internet of Things (IoT) networks would facilitate more effective end-to-end IP network architectures, but it remains a challenge. Network routing needs to be effectively addressed in the IoT environments of scarce computational and energy resources. Accordingly, the Internet Engineering Task Force (IETF) has specified the IPv6 Routing Protocol for Low Power and Lossy Network (RPL) to provide a bespoke IPv6-based routing framework for IoT networks. However, RPL comes with no Quality of Service (QoS) support which is an essential requirement for many IoT applications. The network research community has introduced a number of research proposals enhancing RPL with different QoS solutions. This paper presents a review of these proposed solutions and aims to establish a firm understanding of recent QoS developments for RPL and possible areas for future IoT routing research. The focus is on comprehending the protocol and networking properties that can affect QoS performance in RPL networks. Consideration is also given to different objective functions developed for addressing varying QoS aspects such as throughput, delay, and packet loss. RPL is also extended in a number of QoS solutions following different approaches at the MAC, network, and application layers. However, there is still a need for further developments to address effective QoS support, particularly for dynamic RPL networks.     

基于移动代理的蚂蚁算法在QoS路由选择中的应用研究

随着Internet上广泛的分布式多媒体应用对服务质量（QoS)需求的增长，各种服务应用对网络所能提供的QoS提出了不同的要求，所以高效率的QoS支持越来越显示出其重要性，而路由机制是实现QoS保证的关键之一。首先对一般性的QoS路由选择问题进行了讨论；在分析了自然界中蚂蚁卓越的选路行为后，提出了一种基于智能蚂蚁算法的QoS路由选择算法（QRAP），接着对QRAP算法进行了修正，使之更加符合应用的需求；然后讨论了该算法基于移动代理（Mobile Agent)的应用框架，并且给出了每个移动代理虚拟上应用模块的实现原理；最后通过实验仿真，验证了该算法应用的可行性和有效性。