宽带无线网络中的频谱资源管理综述

在宽带无线网络中,频谱是重要但很稀缺的资源.随着无线网络规模的迅速增长,有限的频谱资源已无法满足日益增长的移动流量.为缓解网络压力、提高频谱资源的利用效率,频谱资源管理机制得到了广泛的关注.首先简述无线通信中频谱资源的基本知识,并分析频谱使用所面临的主要挑战;然后,从传统的静态频谱管理和正在成为主流的动态频谱管理两个方面对宽带无线网络中的频谱资源管理研究进行分类总结和分析评价;最后,从管理架构和关键要素两个层面对频谱资源管理未来研究的发展趋势进行了展望.     

一种多租户云数据存储缓存管理机制

随着云计算的普及,软件即服务(software as a service,SaaS)逐渐成为云计算的一种重要表现形式.云中数据节点的缓存是提高多租户应用数据访问性能的一种重要资源,缓存资源的共享和分配受到SaaS提供商的关注.对SaaS提供商而言,如何在多租户间有效地分配数据节点上的缓存资源,从而满足租户的服务水平协议(service level agreement,SLA),获得更高的收益已成为一项挑战.为此,提出了多租户云数据存储缓存管理机制,以实现服务提供商收益最大化的目标,结合SLA收益模型,评估不同缓存策略下服务提供商获取的收益值,将全局缓存管理问题定义为目标优化问题,并结合缓存分配特点,采用优化的遗传算法解决该问题.通过实验比较,该方法能保证SaaS服务提供商在多租户间有效利用缓存资源获取高收益.     

基于经济学的云资源管理模型研究

结合云计算的特点,在分析计算资源的效用市场基础上,从经济学原理的角度提出了云计算经济学架构,设计了基于SLA的云资源管理经济模型.研究了该模型采用的基于使用量的计费机制、基于SLA的谈判流程,基于效用函数的谈判算法,采用CloudSim模拟工具进行仿真实验和性能分析,实验结果表明,该模型有助于促进云环境下资源的高效管理、优化配置,最大限度地满足用户QoS需求.     

Web文本挖掘相关技术研究及应用

Internet信息量迅猛增长,信息的海量化越来越突出,如何获取用户所需已日益突显出其重要性.文本挖掘技术能快速、有效地从大量数据中抽取有价值的信息,而Internet成为一个拥有大量Web文本资源的巨型数据库,大量异构、非结构化的Web文本对数据挖掘技术提出新的挑战.介绍Web文本挖掘的一般流程,重点分析Web文本挖掘中的几种关键技术.     

一种无线传感器网络与Internet的集成方案

目前对传感网的研究主要解决如何在满足特定应用要求的网络指标下，尽可能节约能耗从而延长网络生存期。这些研究假设WSN为一个能够感知真实物理环境的孤立网。然而，实际客户通常处在远离WSN的Internet上，需要一种有效的方式使客户能驱动WSN收集数据并将其快速地传输给客户，因此该文基于对现有研究进行分析总结，提出了一种能够面对多种挑战的传感网与IP网集成方案，采用用户代理、应用代理、注册代理、资源管理器架设WSN与Internet之间的桥梁。通过组件描述和查询操作流程分析，说明了该集成方案较已有框架更加灵活、可靠、能量有效，从而使Internet不同种类的应用能够尽可能快速地获得低成本的WSN查询服务。     

类电子商务模式的CNERN数据资源管理与服务信息平台

国家生态系统观测研究网络(National Ecosystam Research Network of China, CNERN)平台的数据资源管理与服务模式与开放式电子商务平台架构存在很大的相似性, CNERN 基于 B2B2C 电子商务模式构建了数据资源管理与服务信息平台,有助于改善资源使用者访问和获取数据资源的体验,改进资源提供者进行数据资源管理及数据资源服务的效率。本文分析了数据资源特点,介绍了数据资源内容,详细分析了信息平台架构、系统组成与功能, 介绍了 CNERN 信息平台如何对多方异地管理、异构存储、不同开放服务方式的数据资源进行类似电子商务模式的规范化管理及自动化服务的整体解决方案。     

基于接纳控制和ILP资源调度模型的BDAaaS系统架构

为了使云计算平台为大数据分析提供有效支持,提出一种大数据分析即服务(BDAaaS)的系统架构;首先,当用户向系统提交大数据分析应用(BDAA)时,通过接纳控制器评估任务的执行时间和成本并作出接纳决策;然后,通过服务等级协议(SLA)管理器根据任务的服务质量(QoS)需求制定SLA;最后,利用提出的整数线性规划(ILP)资源调度模型,以最小化执行成本为目标,在满足SLA下合理调度资源来执行任务;仿真结果表明,提出的方案能够有效降低任务执行时间,具有有效性和可行性。     

基于QoS域代理在移动无线互联网中区分服务的设计与实现

随着用户数和应用业务的快速发展,对新一代Internet的服务质量提出了更高的要求。然而,在Internet中引入无线接入方式使得提供QoS面临更大挑战。文章基于区分服务(DiffServ)框架结构,并结合移动管理协议———移动IP(MobileIP)协议来研究和解决如何在新一代移动无线互联网中提供QoS控制。同时在每个自治域中引入一个新的概念———QoS域代理(QoSDomainAgent,QDA),并利用QDA进行资源管理并参与和移动主机/用户(MobileHost,MH)或其它QDA进行动态SLS的协商,同时采用组播方式把QDA中的QoSSLS内容信息传输给域内的每一个第一跳和边界路由节点。通过对相关协议和功能进行必要的修改和扩充,从而有效地解决了MH和网络的动态服务级别协议(SLA)的协商和在MobileIP切换中各入口节点动态建立SLS的问题,同时可以有效减少信令交互,节省无线资源和减少移动终端的电池消耗,并且有利于MH在域内漫游时进行无缝切换。最后给出作者的结论及进一步的研究内容。     

业务效用模型在移动业务管理中的应用

以客户为中心的业务级网络管理目前正成为国际上研究的热点,业务资源管理是其中的关键部分。为了提高业务资源的利用率,必须有一套可对业务资源利用率进行量化的评价模型。论文提出了一种新的业务效用模型SUM,运用该效用模型可以使业务提供商(SP)和网络运营商(NO)结合自身盈利和用户感受定量地对业务资源管理进行评价,帮助SP和NO通过不同的方式分析业务资源管理性能,呈现资源管理参数设置与业务效用之间的关系,发现业务资源管理瓶颈从而最终提高资源利用效率。论文把该效用模型应用于自适应业务资源管理中,仿真结果表明,SUM模型可以很好地定量地反映业务资源的利用率,选取该效用模型作为自适应原则显著提高了系统的资源利用整体效率。     

面向数据的软件体系结构初步探讨

受软件体系结构的限制,信息技术领域长期存在的问题在大数据时代愈发突出:系统间的信息难以共享;已建系统功能扩展困难;海量、异构、多源、动态、实时变化和爆发式增长的大数据难管理,难分析,难挖掘;面向业务的软件工程开发过程复杂,维护困难,生命周期短;在互联网开放环境下的信息安全、数据安全问题面临挑战;数据所有者利益得不到保障等。面向数据的软件体系结构(data-oriented software architecture,DOA),采用"面向数据和以数据为核心"的思想,通过数据注册中心(data register center,DRC)、数据权限中心(data authority center,DAC)和数据异常中心(data exception control center,DEC)统一定义数据、管理数据和提供数据服务;通过数据应用单元(data application units,DAUs)对各种应用进行管理和服务,建立了一种数据大平台与碎片化应用的数据生态系统,为构建大数据时代从数据保护到授权应用整套机制的软件体系结构,进行了有益的探索。     

Balance of power: dynamic thermal management for Internet data centers

Internet-based applications and their resulting multitier distributed architectures have changed the focus of design for large-scale Internet computing. Internet server applications execute in a horizontally scalable topology across hundreds or thousands of commodity servers in Internet data centers. Increasing scale and power density significantly impacts the data center's thermal properties. Effective thermal management is essential to the robustness of mission-critical applications. Internet service architectures can address multisystem resource management as well as thermal management within data centers.     

An SLA-based cloud computing that facilitates resource allocation in the distributed data centers of a cloud provider

The number of cloud service users has increased worldwide, and cloud service providers have been deploying and operating data centers to serve the globally distributed cloud users. The resource capacity of a data center is limited, so distributing the load to global data centers will be effective in providing stable services. Another issue in cloud computing is the need for providers to guarantee the service level agreements (SLAs) established with consumers. Whereas various load balancing algorithms have been developed, it is necessary to avoid SLA violations (e.g., service response time) when a cloud provider allocates the load to data centers geographically distributed across the world. Considering load balancing and guaranteed SLA, therefore, this paper proposes an SLA-based cloud computing framework to facilitate resource allocation that takes into account the workload and geographical location of distributed data centers. The contributions of this paper include: (1) the design of a cloud computing framework that includes an automated SLA negotiation mechanism and a workload- and location-aware resource allocation scheme (WLARA), and (2) the implementation of an agent-based cloud testbed of the proposed framework. Using the testbed, experiments were conducted to compare the proposed schemes with related approaches. Empirical results show that the proposed WLARA performs better than other related approaches (e.g., round robin, greedy, and manual allocation) in terms of SLA violations and the provider’s profits. We also show that using the automated SLA negotiation mechanism supports providers in earning higher profits.     

A generic architecture for autonomic service and network management

As the Internet evolves into an all-IP communication infrastructure, a key issue to consider is that of creating and managing IP-based services with efficient resource utilization in a scalable, flexible, and automatic way. In this paper, we present the Autonomic Service Architecture (ASA), a uniform framework for automated management of both Internet services and their underlying network resources. ASA ensures the delivery of services according to specific service level agreements (SLAs) between customers and service providers. As an illustrative example, ASA is applied to the management of DiffServ/MPLS networks, where we propose an autonomic bandwidth sharing scheme. With the proposed scheme, the bandwidth allocated for each SLA can be automatically adjusted according to the measured traffic load and under policy control for efficient resource utilization, while SLA compliance over the network is always guaranteed.     

支持QoS管理的下一代互联网IP业务的SLA违例处理及应用

为了实现对下一代互联网IP业务的SLA违例处理的规范化管理,保证业务正常、可靠、高质量地提供,定义了一个通用的SLA违例处理模板,详细描述了该模板的组成内容和属性,并在模板的基础上提出了能够保障服务质量的SLA违例处理的流程,最后讨论了与服务参数相关的SLA违例处理在服务保障阶段的应用实例。     

移动因特网中的组成员管理

目前因特网技术和无线技术这两大热点技术结合成最新的一项网络技术——移动因特网计算。基于移动因特网的组成员管理面临新的挑战。组成员管理算法层出不穷,目的是为了简洁、有效地获得正确的组播组成员信息,提高组播通信的服务质量,同时提高网络的资源利用率。该文研究了不同种类的组成员管理,并进行了细致的分类,按各个类别的特点结合算法进行了分析。     

Consolidated cluster systems for data centers in the cloud age: a survey and analysis

In the cloud age, heterogeneous application modes on large-scale infrastructures bring about the challenges on resource utilization and manageability to data centers. Many resource and runtime management systems are developed or evolved to address these challenges and relevant problems from different perspectives. This paper tries to identify the main motivations, key concerns, common features, and representative solutions of such systems through a survey and analysis. A typical kind of these systems is generalized as the consolidated cluster system, whose design goal is identified as reducing the overall costs under the quality of service premise. A survey on this kind of systems is given, and the critical issues concerned by such systems are summarized as resource consolidation and runtime coordination. These two issues are analyzed and classified according to the design styles and external characteristics abstracted from the surveyed work. Five representative consolidated cluster systems from both academia and industry are illustrated and compared in detail based on the analysis and classifications. We hope this survey and analysis to be conducive to both design implementation and technology selection of this kind of systems, in response to the constantly emerging challenges on infrastructure and application management in data centers.     

Some Issues on Computer Networks: Architecture and Key Technologies

The evolution of computer networks has experienced several major steps, and research focus of each step has been kept changing and evolving, from ARPANET to OSI/RM, then HSN （high speed network） and HPN （high performance network）. During the evolution, computer networks represented by Internet have made great progress and gained unprecedented success. However, with the appearance and intensification of tussle, along with the three difficult problems （service customizing, resource control and user management） of modern network, it is found that traditional Internet and its architecture no longer meet the requirements of next generation network. Therefore, it is the next generation network that current Internet must evolve to. With the mindset of achieving valuable guidance for research on next generation network, this paper firstly analyzes some dilemmas facing current Internet and its architecture, and then surveys some recent influential research work and progresses in computer networks and related areas, including new generation network architecture, network resource control technologies, network management and security, distributed computing and middleware, wireless/mobile network, new generation network services and applications, and foundational theories on network modeling. Finally, this paper concludes that within the research on next generation network, more attention should be paid to the high availability network and corresponding architecture, key theories and supporting technologies.     

Profile-based dynamic application assignment with a repairing genetic algorithm for greener data centers

Data centers have become essential to modern society by catering to increasing number of Internet users and technologies. This results in significant challenges in terms of escalating energy consumption. Research on green initiatives that reduce energy consumption while maintaining performance levels is exigent for data centers. However, energy efficiency and resource utilization are conflicting in general. Thus, it is imperative to develop an application assignment strategy that maintains a trade-off between energy and quality of service. To address this problem, a profile-based dynamic energy management framework is presented in this paper for dynamic application assignment to virtual machines (VMs). It estimates application finishing times and addresses real-time issues in application resource provisioning. The framework implements a dynamic assignment strategy by a repairing genetic algorithm (RGA), which employs realistic profiles of applications, virtual machines and physical servers. The RGA is integrated into a three-layer energy management system incorporating VM placement to derive actual energy savings. Experiments are conducted to demonstrate the effectiveness of the dynamic approach to application management. The dynamic approach produces up to 48% better energy savings than existing application assignment approaches under investigated scenarios. It also performs better than the static application management approach with 10% higher resource utilization efficiency and lower degree of imbalance.     

云边协同综述

在物联网、大流量等场景下,传统的云计算具有强大的资源服务能力的优点和远距离传输的缺点,而新兴的边缘计算具有低传输时延的优点和资源受限的缺点,因此,结合了云计算与边缘计算优点的云边协同引起了研究者的广泛关注。在全面调查和分析云边协同相关文献的基础上,文中重点分析和讨论了资源协同、数据协同、智能协同、业务编排协同、应用管理协同和服务协同等协同技术的实现原理和研究思路与进展。然后分别从云端和边缘端深入分析了各种协同技术在协同中所起的作用以及具体的使用方法,并从时延、能耗以及其他性能指标方面对结果进行了对比分析。最后指出了云边协同目前存在的挑战和未来的发展方向。本综述有望为云边协同的研究提供有益的参考。     

Distributed access management in multimedia IDCs

Future Internet data centers that provide multimedia content face security challenges requiring appropriately designed policies to manage resource access. An example from the healthcare domain shows how an access management framework can address these challenges.