多策略QoS感知的服务选择与排序模型

随着网络中具有相同功能、不同QoS服务的增多,在用户请求服务时,为了确保能找到满足用户功能与质量要求的服务,并对找到的可用候选服务集按一定的策略进行选优,提出了一种多策略QoS感知的服务选择与排序模型。在该模型中,综合考虑服务的性能与运营维护成本等属性,提出了一个扩展的服务QoS模型,在此基础上引入用户、运营商对服务满意度的计算方法,通过改变用户满意度与运营商满意度在排序选优过程中所占的不同比重,灵活设置服务选优策略,有效的解决了服务排序选优问题。搭建了服务选择与排序原型系统,并通过应用实例对上述模型进行了验证。     

QoS-aware computational method for IoT composite service

This paper integrated the quality of service (QoS) requirements of Internet of things (IoT) composite services, and put forward effective decomposition and optimization methods of the QoS metrics. The authors break down the complex QoS calculation model into four basic models, and each model is given a computational method. Combined with the QoS technology of the composite service, the authors adopt the algorithm to find the sub-optimal service with an acceptable cost under the QoS constraints. The proposed algorithm can quickly provide QoS computing services than other two algorithms for large-scale IoT compose services.     

A balancing scheme for QoS-aware service provisioning in OPS networks

The service level agreement (SLA) specifies the service availability that a service provider promises to a customer. Through introducing SLA into optical packet switching networks, a balancing scheme for quality of service-aware service provisioning is proposed, which uses packet loss ratio as availability index to obtain a larger number of SLA-satisfied services and achieve a better balance among different level services by means of discarding packets with better packet loss capacity in priority to fully make use of the capacity of services themselves. The theoretical analysis and simulation results show that the proposed scheme outperforms the other two typical service provisioning schemes in terms of the above two aspects.     

QoS-aware adaptation for satellite multimedia broadcasting via hierarchical packet scheduling

With the unique broadcast nature and ubiquitous coverage of satellite networks, the synergy between satellite and terrestrial networks provides opportunities for delivering wideband services to a wide range of audiences over extensive geographical areas. This article concerns the optimization techniques pertinent to packet scheduling to facilitate multimedia content delivery over the satellite with a return channel via a terrestrial network. We propose a novel hierarchical packet scheduling scheme that allocates the resources at different parts of the network in response to network dynamics and link variations while under the system power/resource constraints. Simulations prove that the HPS scheme can effectively improve the end-to-end performance and resource utilization with desirable scalability and fairness features.     

An architecture for autonomic security adaptation

Communication is the grounding principle of nowadays complex applications where the functionalities of the overall system are much more powerful then the ones of the isolated components. The task of keeping the communication system operable is highly critical due to the configuration complexity and the need for manual administration. Autonomous configuration mechanisms offer a compelling solution for the communication problem. We present an architecture for the autonomous configuration of secure, layer independent, end-to-end connections in this paper. The Extensible Security Adaptation Framework (Esaf) separates the particularities of communication setups strictly from the communication usage by the applications. Applications are unaware of the utilized security mechanisms and the complex configuration thereof. Protocols and security primitives can be easily introduced into the system whereas others might be disabled due to vulnerabilities without the need to modify existing programs. Moreover the setup can adapt to changing environments dynamically during runtime.     

Scalable service migration in autonomic network environments

Service placement is a key problem in communication networks as it determines how efficiently the user service demands are supported. This problem has been traditionally approached through the formulation and resolution of large optimization problems requiring global knowledge and a continuous recalculation of the solution in case of network changes. Such approaches are not suitable for large-scale and dynamic network environments. In this paper, the problem of determining the optimal location of a service facility is revisited and addressed in a way that is both scalable and deals inherently with network dynamicity. In particular, service migration which enables service facilities to move between neighbor nodes towards more communication cost-effective positions, is based on local information. The migration policies proposed in this work are analytically shown to be capable of moving a service facility between neighbor nodes in a way that the cost of service provision is reduced and - under certain conditions - the service facility reaches the optimal (cost minimizing) location, and locks in there as long as the environment does not change; as network conditions change, the migration process is automatically resumed, thus, naturally responding to network dynamicity under certain conditions. The analytical findings of this work are also supported by simulation results that shed some additional light on the behavior and effectiveness of the proposed policies.     

Market-based self-optimization for autonomic service overlay networks

Rather than managing their heterogeneity and dynamic behavior through centralized intervention, overlay nodes can be programmed to self-organize and self-manage the network. To achieve the highest performance within a service overlay, they are further expected to self-optimize the network, by cooperatively providing and allocating resources in an optimal manner. However, since nodes are inherently selfish about resources they contribute or consume, self-optimization could not be achieved if they are not given the correct incentives. In this paper, we investigate the effectiveness of a market-based incentive mechanism in directing nodes' behavior and enabling self-optimizations. We have designed an intelligent market model for a service overlay network, based on which individual nodes, being service producers and consumers, determine their own resource contributions, consumptions, or service prices based on their own utility maximization goals. We also propose optimal decision making solutions for nodes to achieve their self-interests; in particular, service providers are provided with a control-based pricing solution based on system identification techniques. With the multicast streaming application as an example, we show through simulations that, even when selfish nodes all seek their maximal utilities, the resulting network still achieves close-to-optimal performance in both steady and dynamic states. The results also indicate that, by encouraging nodes to behave selfishly and intelligently in a designed market, self-optimization in other autonomic systems may be facilitated in the presence of node selfishness.     

Semantics-based dynamic service composition

Complex services may be dynamically composed through combining distributed components on demand (i.e., when requested by a user) in order to provide new services without preinstallation. Several systems have been proposed to dynamically compose services. However, they require users to request services in a manner that is not intuitive to the users. In order to allow a user to request a service in an intuitive form (e.g., using a natural language), this paper proposes a semantics-based service composition architecture. The proposed architecture obtains the semantics of the service requested in an intuitive form, and dynamically composes the requested service based on the semantics of the service. To compose a service based on its semantics, the proposed architecture supports semantic representation of components [through a component model named Component Service Model with Semantics (CoSMoS)], discovers components required to compose a service [through a middleware named Component Runtime Environment (CoRE)], and composes the requested service based on its semantics and the semantics of the discovered components [through a service composition mechanism named Semantic Graph-Based Service Composition (SeGSeC)]. This paper presents the design, implementation and empirical evaluation of the proposed architecture.     

QoS-aware joint working packet scheduling and call admission control for video streaming service over WiMAX network

In this paper, we propose a QoS-aware joint working packet scheduling algorithm and call admission control algorithm to support stable video streaming service to more subscribers over WiMAX network. The proposed call admission control algorithm estimates the network throughput by using a local linear model in terms of a control parameter of the proposed scheduling algorithm, and performs its own functions based on the information. The proposed scheduling algorithm continuously updates the control parameter to pursue an effective tradeoff between the quality-of-service of video streaming and the network throughput. Finally, simulation results are provided to show the performance of the proposed video streaming system.     

航海保障通信业务服务属性的研究及思考

文章从航海保障通信业务现有管理架构、公约法规、事业属性等几个方面,对航海保障通信业务服务属性进行研究和分析。     

Multimedia adaptation for the multimedia messaging service

This article provides an overview of the multimedia messaging service. It also addresses the interoperability challenges this new service brings as mobile terminal capabilities evolve at a very fast pace. It explains how server-side multimedia message adaptation technologies can provide smooth format and service evolution while ensuring interoperability.     

彩铃业务在专用通信网中的应用

目前,传统固网业务的发展日趋平缓,各种新型的增值业务已经成为电信产业发展的主旋律,详细阐述了在网络运营中,依托专用通信网络为业务支撑平台,应用话路迂回、CTI SERVER等技术手段,采用开放式系统结构设计,建设一个易于各型号交换机互联、系统稳定可靠、反应快速、维护简单的彩铃业务系统建设方案,为专用通信网建设彩铃业务提供一个可供参考的建设模式.     

PPDR业务与通信频率规划

首先介绍了PPDR与传统应急救灾系统相比的优势，然后阐述了PPDR提供的业务．最后论述了ITU—R为PPDR规划频段的原则及其候选频段。     

制造云服务组合中支持服务关联的QoS感知评估模型

为了更好地从大量候选云服务集中选出满足制造需求且服务质量较优的制造云服务协同完成制造任务,针对QoS准确性给组合筛选带来的影响,基于接口关联、业务实体关联、统计关联,提出了一种支持服务关联的QoS感知评估模型。引入企业合作时间、KULC和IR参数,利用历史信息进行预测对统计关联QoS变化量进行动态调整,保证了时效性。通过算例分析验证了所提方法的可行性,实验结果表明该方法能为服务需求方提供更切合实际的解决方案。     

Advanced reconfiguration framework based on game theoretical techniques in autonomic communication systems

The Autonomic Communications concept forms one promising solution to accommodate the increased complexity of legacy and emerging systems, fostering the automation and minimizing the need for human intervention. This notion implies the introduction of advanced mechanisms for autonomic decision making and self-configuration. The focus of this work is on the introduction of an advanced reconfiguration framework for the support of the following functionalities: i) efficient strategies of terminal attachment to heterogeneous wireless systems are proposed dependent on the evaluation of input stimuli from the surrounding telecom environment. ii) it is shown how to enable optimized selection and attribution of resources, iii) the application of new device configuration is examined, proposing a framework for dynamic protocol stack adaptation. It is indeed necessary to introduce a framework that will enable, policy based reconfiguration decisions supporting dynamic and optimal discovery, download and replacement of necessary protocol functionality. In this context, legacy management and control mechanisms should be enriched with such features operating in either terminal or network equipment. Namely, this contribution discusses cognitive reconfiguration management issues by introducing two basic reconfiguration units encapsulated in a unified management and control architecture: i) the component based protocol stack reconfiguration framework and ii) the resource usage optimization unit. Simulation and performance results presented in the paper prove the technical feasibility of the proposed mechanisms as well as the optimization of reconfiguration actions.     

基于Alloy的服务组合验证

服务组合是服务计算的核心问题,而服务组合的正确性与可算性则是服务正确执行的前提保证。首先提出一种基于Alloy的服务组合验证方法,采用有限的状态机建模WS-BPEL业务流程的状态变迁,利用Alloy语言对待验证的属性进行描述,通过Alloy模型完成有限状态机的形式化,最后使用Alloy Analyzer分析组合服务是否满足验证属性要求。实验研究表明,所提出的基于Alloy的服务组合验证方法具有较好的可行性。     

A multipoint communication service for interactive applications

The multipoint communication layer (MCL) is a generic multipoint communication service designed to support highly interactive multimedia conferencing applications. It supports full-duplex multipoint communication between an arbitrary number of connected locations over a variety of networks. MCL design was driven by the demanding real-time multipoint communication requirements of MICA (multimedia interactive conferencing application). The authors establish the context for MCL by considering MICA's communication requirements and reviewing related work in the area of multipoint communication. They present the overall design of the MCL service and describe its communication primitives, protocol message structures, and implementation. Comparison is made with alternative strategies and the use of MCL services for other applications is examined     

网络功能虚拟化中的性能感知服务组合优化

服务功能链是网络功能虚拟化的重要支撑,为了构建满足功能和性能需求的服务功能链,需要建立服务的性能模型,从而产生基于性能的服务组合优化问题。一种基于性能模型的服务组合优化问题被建模,并针对复杂约束情况下的无效解干扰,提出了改进的模拟退火算法,该算法包含基于层次属性的产生函数和基于偏离度的目标函数。仿真结果表明,该算法提高了21%的服务组合成功率,同时降低了组合成本和时间消耗。仿真结果验证了所提算法的有效性。     

铁通黑龙江分公司主要业务及发展

概述了铁通黑龙江分公司的现有通信资源、网络覆盖能力及队伍建设情况 ,介绍了铁通黑龙江分公司经营的主要通信业务及今后的发展重点。     

Background replacement using chromatic adaptation transform for visual communication

Replacing a video chat background with a landscape image can generate the realism of a user actually being in the landscape. To enhance this realism, we proposed in our previous study a background replacement method that uses a chromatic adaptation transform. This method can enhance the realism of video chat by fitting the color of the foreground image to an illuminant color of a landscape, which is used as the new background image. However, if an incorrect color of the landscape illuminant is obtained through this method, which estimates the illuminant color on the basis of a gray world assumption, the method might not enhance the realism. This is because it converts the foreground color to an incorrect color. In this paper, we therefore propose a method to estimate illuminant color on the basis of the dichromatic reflection model, which improves background replacement using the chromatic adaptation transform. We perform a subjective evaluation using 13 subjects to examine the effects of the proposed method. The results indicate that the proposed method can effectively enhance the realism of the background replacement video.