Content Protective Multi‐Agent Platform for MsMu Service and Pattern‐Based Content Management

Recent research on mobile Internet protocol television and digital right management (DRM) interconnections has focused on multimedia technologies designed to enhance content scalability and adaptive content distribution. However, due to the architectural and scalable limitations, recent systems are not flexible and securable with respect to their adaptive content distribution and protective policy management. Therefore, we propose a content protective multi‐agent platform that provides secure multimedia services, correlation management, pattern‐based management, and multisource multi‐use (MsMu)‐based services. Our architecture, supported by DRM, lets us create a rich set of MsMu‐based content protection and seamless multimedia services through the extension of one source multi‐use (OsMu)‐based content services. We have verified our platform, which provides scalable and securable services with a 17% lower service response time by using a testbed.     

Cloud‐Based Gaming Service Platform Supporting Multiple Devices

To implement a cloud game service platform supporting multiple users and devices based on real‐time streaming, there are many technical needs, including game screen and sound capturing, audio/video encoding in real time created by a high‐performance server‐generated game screen, and real‐time streaming to client devices, such as low‐cost PCs, smart devices, and set‐top boxes. We therefore present a game service platform for the running and management of the game screen, as well as running the sound on the server, in which the captured and encoded game screen and sound separately provide client devices through real‐time streaming. The proposed platform offers Web‐based services that allow game play on smaller end devices without requiring the games to be installed locally.     

Popularity–Based Adaptive Content Delivery Scheme with In‐Network Caching

To solve the increasing popularity of video streaming services over the Internet, recent research activities have addressed the locality of content delivery from a network edge by introducing a storage module into a router. To employ in‐network caching and persistent request routing, this paper introduces a hybrid content delivery network (CDN) system combining novel content routers in an underlay together with a traditional CDN server in an overlay. This system first selects the most suitable delivery scheme (that is, multicast or broadcast) for the content in question and then allocates an appropriate number of channels based on a consideration of the content's popularity. The proposed scheme aims to minimize traffic volume and achieve optimal delivery cost, since the most popular content is delivered through broadcast channels and the least popular through multicast channels. The performance of the adaptive scheme is clearly evaluated and compared against both the multicast and broadcast schemes in terms of the optimal in‐network caching size and number of unicast channels in a content router to observe the significant impact of our proposed scheme.     

内容分发网络研究

内容分发网络是一种以降低互联网访问时延为目的,在网络边缘或核心交换区域部署内容代理服务,通过全局负载调度机制进行内容分发的新型覆盖网络体系.随着多媒体网络流及实时交互技术的兴起,现今内容分发网络已成为互联网的核心应用之一.本文介绍了内容分发网络的演变过程与体系结构,深入剖析了内容分发网络的核心功能组件与工作机制,对当前主流内容分发网络进行分类,并讨论了内容分发网络性能度量,最后探讨了内容分发网络的未来挑战与进一步研究方向.     

CACTSE：基于云片式多终端协同服务环境的移动近场内容分发

Along with the rapid development of communications, the Internet, and smart terminals, mobile Internet has become a hot topic with both opportunities and challenges. In this article, a new perspective on edge content delivery service for mobile Internet is described, based on cooperating terminals. A mobile cloud architecture named Cloudlet Aided Cooperative Terminals Service Environment (CACTSE) is proposed as an edge network service environment. The Service Manager (SM), a cloudlet like module, is introduced into the local service domain in order to manage the in-domain terminals and help coordinate the content delivery requests for better bandwidth efficiency as well as user experience. The reference model is presented in this article with architecture and mechanism design. Moreover, the research progress and potential technology trends of CACTSE are analysed based on the related R&D directions.     

Metadata and API Based Environment Aware Content Delivery Architecture

1IntroductionWiththe popularization of broadband network serviceand the rapid development of broadband applicationswith streaming media,the Quality of Service(QoS)requirement of networks is also increasing greatly.Althoughthe bandwidth is increasing and t…     

面向动态环境的虚拟光网络资源优化算法

为解决采用单个虚拟网特征重配置导致虚拟网接受率低的问题,基于资源竞争特征重构底层网络模型,并基于此构建虚拟网映射线性规划模型。设计了无划分的随机舍入优化算法和有划分的随机舍入优化算法,为每个虚拟网分配全局最优的底层网络资源。与现有算法相比,该算法下虚拟网请求的平均接受率提升11%,节点资源平均利用率提升61%,链路资源平均利用率提升27%。     

基于内容分发网络的视频通信系统研究

随着宽带技术和业务的发展以及人们对视频通信需求的增长,视频通信业务和技术得到了大规模的发展。首先比较了目前各种实现方案的特点和不足;然后基于内容分发网络技术及系统,提出了一种低成本、高扩展性、高质量视频通信的系统方案,详细叙述了该方案的结构、流程及特点;最后给出了验证系统的初步结果。     

一种面向电力无线专网的虚拟资源优化分配机制

为了有效地保证智能电网中业务的隔离性和解决智能电网无线资源高效分配问题,该文借助网络虚拟化技术,提出一种面向电力无线虚拟专网的资源优化分配机制。首先,根据电力无线专网的特点,提出电力无线专网虚拟化系统模型,并通过建立网络模型抽象物理无线资源,实现资源共享;然后,综合网络成本、利润、业务隔离性约束、回程容量约束、QoS约束等因素,提出配用电接入网无线资源分配模型,且设计一种禁忌搜索的算法,在满足业务隔离和业务QoS要求的情况下,解决了配用电无线专网最优化虚拟资源分配。仿真实验表明,该文提出的基于禁忌搜索的电力无线虚拟专网资源优化分配机制,在满足业务QoS要求的情况下,降低了基站能耗,并提高了网络运行的经济效益。     

Distributed Resource Allocation in Two‐Hierarchy Networks

In this paper, a new distributed resource allocation algorithm is proposed to alleviate the cross‐tier interference for orthogonal frequency division multiplexing access macrocell and femtocell overlay. Specifically, the resource allocation problem is modeled as a non‐cooperative game. Based on game theory, we propose an iterative algorithm between subchannel and power allocation called distributed resource allocation which requires no coordination among the two‐hierarchy networks. Finally, a macrocell link quality protection process is proposed to guarantee the macrocell UE's quality of service to avoid severe cross‐tier interference from femtocells. Simulation results show that the proposed algorithm can achieve remarkable performance gains as compared to the pure waterfilling algorithm.     

一种支持云计算虚拟资源分配的可信多需求拍卖机制

使用拍卖方式来进行资源分配可以使得资源提供商获得更大的收益,是云计算领域近年来研究的重点。但现有研究多是基于非可信、单资源、单需求的前提。该文提出一种基于拍卖方式的云计算虚拟资源分配和定价机制(VRAP)。这种机制的特点在于,用户在一次拍卖中可以提出多个资源需求。证明了在这种机制下,资源提供商可以获得较以往拍卖机制更大的收益,同时能够保证用户出价是可信的。进而在具体资源分配问题上,提出一种单调的启发式算法能够在很短时间内计算出分配结果,通过资源稀有度概念设计了再分配策略,可以保证云资源提供商的收益极大化;在支付价格计算算法设计中,基于临界值理论计算支付价格,从而保证机制的公平可信。在社会福利、执行时间、资源利用率等多个方面对VRAP进行了测试分析,取得了很好的效果。     

移动流媒体内容传输网络模拟器的设计和实现

通过扩展和修改内容传输网络模拟器CDNsim,设计和实现了更能适应移动流媒体内容传输网络需求的网络模拟器:MSM-CDN模拟器,以缓解MSM-CDN研究中缺少实验环境的限制.MSM-CDN模拟器在CDNsim中新增了入口服务器、管理服务器和无线用户小区等节点,使用了一种能有效减少CPU开销和节省内存空间的路由实现方式以及支持多文件请求的SMIL文件处理算法.实验结果表明,MSM-CDN模拟器能较好地用于MSM-CDN的缓存服务器路由策略、缓存策略和缓存服务器配置的仿真研究.     

Market Efficiency Analysis between Facility‐Based and Service‐Based Competition

Facility‐based competition (FBC) in the telecommunications market is considered to have lower static efficiency in the short term and higher dynamic efficiency in the long term. Under service‐based competition (SBC), the entrant can reduce its setup costs by leasing network facilities from the incumbent, which makes the entrant viable, pushes the market price down and promotes static efficiency. This paper attempts to measure static efficiency by comparing the profits of the incumbent and entrant in terms of consumer surplus and social welfare under each competition type by extending the Stackelberg model. The results, assuming a linear demand function and variation in regulatory level, show that FBC results in higher social welfare than SBC on the whole. However, SBC accompanied by strong regulation is also shown to have the potential to be superior over FBC. It is also revealed that FBC exhibits a higher producer surplus (particularly, the incumbent's producer surplus) and is, therefore, more desirable in terms of dynamic efficiency. When the entrant's cost is high in FBC, social welfare is shown to be lowered, implying that cost competitiveness is a necessary condition for social welfare.     

面向虚拟路由器的基于历史转发开销的资源调度算法

通过研究以Xen为代表的虚拟工具中资源调度算法,得知它们无法保证虚拟路由器中资源共享的公平性。该文提出一种基于历史转发开销的资源调度算法,用来确保路由器实例占用资源的公平性,尤其物理平台的输入/输出(I/O)资源。该算法通过统计路由器实例最近的报文转发开销来计算出路由器实例调度的优先级,确保平均吞吐量较低的路由器实例获得被调度的机会。同时,该算法通过设置优先级计算公式中处理延迟的值,达到对延迟敏感强的路由器实例的支持,以及通过预测报文处理时间决定待处理报文是否丢弃,避免不必要的系统开销。通过实验测试,相对于Credit算法,该文算法在确保虚拟路由器资源共享的公平性方面存在明显优势,并且能为延迟敏感的路由器实例提供支持。     

Delivery of Two‐Part Self‐Healing Chemistry via Microvascular Networks

Multiple healing cycles of a single crack in a brittle polymer coating are achieved by microvascular delivery of a two‐part, epoxy‐based self‐healing chemistry. Epoxy resin and amine‐based curing agents are transported to the crack plane through two sets of independent vascular networks embedded within a ductile polymer substrate beneath the coating. The two reactive components remain isolated and stable in the vascular networks until crack formation occurs in the coating under a mechanical load. Both healing components are wicked by capillary forces into the crack plane, where they react and effectively bond the crack faces closed. Healing efficiencies of over 60% are achieved for up to 16 intermittent healing cycles of a single crack, which represents a significant improvement over systems in which a single monomeric healing agent is delivered.     

Dynamic bandwidth allocation and buffer dimensioning under equal segment scheme to support video‐on‐demand services

This paper focuses on the optimization of network bandwidth allocation and buffer dimensioning to transport pre‐stored MPEG video data from source to playback destination across ATM networks. This is one of the most important issues in the support of video‐on‐demand (VoD) service. This paper provides a novel scheme in the dynamic allocation of bandwidth to segments of video using ABR mode. The dynamic bandwidth allocation is based on a new concept, called playback tunnel which is obtained from the traffic characteristics of the pre‐stored MPEG video trace to determine the optimum of transmission bandwidth as well as the buffer capacity to ensure that the playback buffer neither underflows nor overflows. The proposed scheme is tested with real‐life MPEG video traces. The obtained results have shown its significant performance improvement in terms of the capacity of playback buffer, the start‐up playback delay, the size of video segment and the network multiplexing gain. Copyright © 2001 John Wiley & Sons, Ltd.     

Network View and Cognitive Mechanism for Virtual Network Resource Management Based Intelligent

Network virtualization has been a particularly important driving force behind the development of NGN. Finding effective ways to control self-adapting virtual networks has become a research hot spot. This paper tries to find an efficient way in combining dynamic resource sensing with traffic character and requirements in virtual network, based on that an intelligent cognition based virtual network resources management model has been put forward. We design a network topology view by coloring network topology matrix with current resources model. We present an intelligent virtual resource management mechanism based on the proposed network topology view. Experiment results illustrate that the proposed mechanism can improve VN capacity by automatic resource adjustment, which can obtain high utilization of VN resources without increasing computational expenses.     

Dynamic Probabilistic Caching Algorithm with Content Priorities for Content‐Centric Networks

This paper presents a caching algorithm that offers better reconstructed data quality to the requesters than a probabilistic caching scheme while maintaining comparable network performance. It decides whether an incoming data packet must be cached based on the dynamic caching probability, which is adjusted according to the priorities of content carried by the data packet, the uncertainty of content popularities, and the records of cache events in the router. The adaptation of caching probability depends on the priorities of content, the multiplication factor adaptation, and the addition factor adaptation. The multiplication factor adaptation is computed from an instantaneous cache‐hit ratio, whereas the addition factor adaptation relies on a multiplication factor, popularities of requested contents, a cache‐hit ratio, and a cache‐miss ratio. We evaluate the performance of the caching algorithm by comparing it with previous caching schemes in network simulation. The simulation results indicate that our proposed caching algorithm surpasses previous schemes in terms of data quality and is comparable in terms of network performance.     

Test Scheduling of NoC‐Based SoCs Using Multiple Test Clocks

Network‐on‐chip (NoC) is an emerging design paradigm intended to cope with future systems‐on‐chips (SoCs) containing numerous built‐in cores. Since NoCs have some outstanding features regarding design complexity, timing, scalability, power dissipation and so on, widespread interest in this novel paradigm is likely to grow. The test strategy is a significant factor in the practicality and feasibility of NoC‐based SoCs. Among the existing test issues for NoC‐based SoCs, test access mechanism architecture and test scheduling particularly dominate the overall test performance. In this paper, we propose an efficient NoC‐based SoC test scheduling algorithm based on a rectangle packing approach used for current SoC tests. In order to adopt the rectangle packing solution, we designed specific methods and configurations for testing NoC‐based SoCs, such as test packet routing, test pattern generation, and absorption. Furthermore, we extended and improved the proposed algorithm using multiple test clocks. Experimental results using some ITC’02 benchmark circuits show that the proposed algorithm can reduce the overall test time by up to 55%, and 20% on average compared with previous works. In addition, the computation time of the algorithm is less than one second in most cases. Consequently, we expect the proposed scheduling algorithm to be a promising and competitive method for testing NoC‐based SoCs.     

Distributed Scheduling and Resource Allocation for Cognitive OFDMA Radios

Scheduling spectrum access and allocating power and rate resources are tasks affecting critically the performance of wireless cognitive radio (CR) networks. The present contribution develops a primal-dual optimization framework to schedule any-to-any CR communications based on orthogonal frequency division multiple access and allocate power so as to maximize the weighted average sum-rate of all users. Fairness is ensured among CR communicators and possible hierarchies are respected by guaranteeing minimum rate requirements for primary users while allowing secondary users to access the spectrum opportunistically. The framework leads to an iterative channel-adaptive distributed algorithm whereby nodes rely only on local information exchanges with their neighbors to attain global optimality. Simulations confirm that the distributed online algorithm does not require knowledge of the underlying fading channel distribution and converges to the optimum almost surely from any initialization.