Dynamic Video Transcoding in Mobile Environments

A transcoder with dynamic feedback addresses interactivity, packet loss, and client power constraints in mobile communication systems.     

移动泛在环境中的分布式终端技术

未来的无线接入技术的异构性使得终端向着可重构的方向发展,而个人周边的智能设备逐渐增多,成为未来移动业务不可忽视的一部分,两者的结合将引出一种新的重构方式,通过个人周边智能设备的协同工作,构成一个分布式的终端系统,不仅能够适应不同接入网的变化,而且能更充分地利用个人周边智能设备的业务能力,为用户提供更佳业务体验。     

采用移动代理的分布式网络管理

文章给出了一种采用移动代理的网络管理方案。该方案通过移动代理将管理智能分布到网元,降低了网管平台的开销和网络负荷,可改善网管系统的可扩展性。文章最后还描述了该方案的系统结构和应用。     

Distributed Coalition Formation Games for Secure Wireless Transmission

Cooperation among wireless nodes has been recently proposed for improving the physical layer (PHY) security of wireless transmission in the presence of multiple eavesdroppers. While existing PHY security literature answered the question “what are the link-level secrecy rate gains from cooperation?”, this paper attempts to answer the question of “how to achieve those gains in a practical decentralized wireless network and in the presence of a cost for information exchange?”. For this purpose, we model the PHY security cooperation problem as a coalitional game with non-transferable utility and propose a distributed algorithm for coalition formation. Using the proposed algorithm, the wireless users can cooperate and self-organize into disjoint independent coalitions, while maximizing their secrecy rate taking into account the costs during information exchange. We analyze the resulting coalitional structures for both decode-and-forward and amplify-and-forward cooperation and study how the users can adapt the network topology to environmental changes such as mobility. Through simulations, we assess the performance of the proposed algorithm and show that, by coalition formation using decode-and-forward, the average secrecy rate per user is increased of up to 25.3 and 24.4% (for a network with 45 users) relative to the non-cooperative and amplify-and-forward cases, respectively.     

基于安全的移动代理网络管理模型的研究

Java卡是一种多功能且安全的智能卡，它能够运行Java程序，具有高度的可移植性和安全性．基于安全的移动代理网络管理模型利用Java卡和加密技术保护执行网络管理任务的移动代理。防止恶意主机的攻击．详细的研究其构成、网络管理过程和相关的安全问题．     

Verifiable Distributed Oblivious Transfer and Mobile Agent Security

The mobile agent is a fundamental building block of the mobile computing paradigm. In mobile agent security, oblivious transfer (OT) from a trusted party can be used to protect the agent’s privacy and the hosts’ privacy. In this paper, we introduce a new cryptographic primitive called Verifiable Distributed Oblivious Transfer (VDOT), which allows us to replace a single trusted party with a group of threshold trusted servers. The design of VDOT uses a novel technique called consistency verification of encrypted secret shares. VDOT protects the privacy of both the sender and the receiver against malicious attacks of the servers. We also show the design of a system to apply VDOT to protect the privacy of mobile agents. Our design partitions an agent into the general portion and the security-sensitive portion. We also implement the key components of our system. As far as we know, this is the first effort to implement a system that protects the privacy of mobile agents. Our preliminary evaluation shows that protecting mobile agents not only is possible, but also can be implemented efficiently. This work was supported in part by the DoD University Research Initiative (URI) program administered by the Office of Naval Research under grant N00014-01-1-0795. Sheng Zhong was supported by ONR grant N00014-01-1-0795 and NSF grants ANI-0207399 and CCR-TC-0208972. Yang Richard Yang was supported in part by NSF grant ANI-0207399. A preliminary version of this paper was presented at the DialM-POMC Joint Workshop on Foundations of Mobile Computing in 2003. Sheng Zhong received his Ph.D. in computer science from Yale University in the year of 2004. He holds an assistant professor position at SUNY Buffalo and is currently on leave for postdoctoral research at the Center for Discrete Mathematics and Theoretical Computer Science (DIMACS). His research interests, on the practical side, are security and incentives in data mining, databases, and wireless networks. On the theoretical side, he is interested in cryptography and game theory. Yang Richard Yang is an Assistant Professor of Computer Science at Yale University. His research interests include computer networks, mobile computing, wireless networking, sensor networks, and network security. He leads the LAboratory of Networked Systems (LANS) at Yale. His recent awards include a Schlumberger Fellowship and a CAREER Award from the National Science Foundation. He received his B.E. degree from Tsinghua University (1993), and his M.S. and Ph.D. degrees from the University of Texas at Austin (1998 and 2001).     

异构环境下基于移动代理的主动自组网构架

分析了移动自组网的异构性、路由协议和能量保护问题,应用移动代理和主动网络技术,给出了一个开放的、扩展性强的基于移动代理的主动自组网构架,该构架通过分群策略,使多个路由协议能在异构环境下并行工作,而且也满足移动节点能量保护的需求。     

基于移动代理的网格计算环境下的资源管理的研究

根据网格计算环境的各种特点,分析比较了网格计算环境下各种资源调度模型,得出采用分布式资源调度的体系结构和基于移动代理的资源管理策略的可行性和必要性.论述了在网格计算环境下引入移动代理技术对于解决网格计算问题的作用和优点,提出了基于移动代理的资源管理模型,并分析了在此系统中采用的资源发现算法及资源调度策略.     

基于移动Agent的分布式层次化入侵检测系统

在目前的入侵检测系统中 ,由于检测组件的位置固定和通信的问题 ,使得入侵检测系统本身易受到攻击 ,为此提出将内部节点封装为移动Agent。此外 ,为了保障系统的安全 ,特别讨论了移动Agent位置随机化、Agent之间安全通信、选举服务器等多种机制以提高抵抗攻击的能力     

移动通信环境中多媒体服务的动态资源分配

由于需求的显著增加，产生了在移动通信环境中提供多媒体服务的问题。本文根据对支持多媒体服务的基站的系统要求，介绍一个动态资源分配方案，该方案可以为陆基和移动环境间的接口提供一个框架。     

基于移动agent的分布式仿真体系框架研究

基于HLA(high level architecture,高层体系结构)的分布式仿真技术是国内外研究的重点。文中依据原有的HLA分布式仿真体系架构的一般特征,设计出基于移动agent的分布式仿真体系框架。在设计中引入了各类功能各异的移动agent,让这些agent分布在仿真节点和联邦中,承担传统HLA体系中的RTI接口规范．协助实现仿真系统功能。移动agent技术的引入,有助于整个系统加强规范性,提高复用性,增加互操作性。     

Energy-Efficient Resource Allocation in Mobile Networks with Distributed Antenna Transmission

This paper address the energy conservation issues in wireless downlink of mobile networks with distributed antenna transmission. From the basic information theory for MIMO channels, we derived a simple energy efficiency defined as number of bits per Watt. we then identified three approaches to improve the optimal energy efficiency with a higher capacity, which include alleviating channel fading loss, mitigating the interference, and increasing the number of antennas. We considered the scenario of a single cell with distributed antennas to jointly investigate above three factors. We first proposed a beamforming based energy-efficient resource allocation algorithm, which can achieve the optimal energy efficiency with a higher capacity through adaptively allocating resources and managing interferences. Due to the computational complexity of this algorithm and real-time processing requirement, we further proposed a low-complexity antenna-selection based resource allocation algorithm, which is more tractable and only with slightly performance loss. Finally, we compared different network configurations with these algorithms by extensive simulations, the results demonstrate that the proposed algorithms in distributed antenna configurations achieve better energy efficiency at a high operational throughput point.     

分布式移动代理系统的事务管理及死锁检测研究

讨论了并发执行的移动代理间的一致性控制问题,给出了移动代理的形式模型及其交互执行的正确性准则,然后基于上述模型,提出了一种有效的分布式死锁检测算法,该算法具有独立于网络的拓扑结构,死锁的检测和事务代理的执行异步操作,不对代理的移动性施加任何限制等特点。     

一种基于移动Agent的分布式Skyline查询算法

针对分布式计算环境,利用移动Agent技术提出了一种基于移动Agent的分布式Skyline查询算法,并进行了深入的分析。通过分析可知,该算法可以实现在分布式环境下求解全局Skyline点。     

Multilevel Location Trigger in Distributed Mobile Environments for Location‐Based Services

In location‐based services, most trigger technologies have been implemented on the server side by periodically requesting the locations of mobile phones from mobile network servers. However, bottlenecks and communication interruptions occur when the servers are overloaded by trigger requests. In this letter, we propose a new multilevel location trigger specification which distributes the event detecting role to mobile phones and redesigns the location triggering into a multilevel step. Our suggested location trigger specification can reduce bottlenecks caused by triggers in a mobile core network and reduce power consumption caused by embedded GPS devices in mobile phones.     

Dynamic Architecture for Collaborative Distributed Storage of Collected Data in Fog Environments

Wireless Personal Communications - Fog computing needs, particularly in terms of performance, availability and reliability, are increasing every day due to the rapid growth in the number of...     

An Efficient Dynamic Integration Middleware for Cyber-Physical Systems in Mobile Environments

Advances in information technologies have brought a wide variety of computing environments. In recent years, integrations of computational, networking, and physical elements in different environments tend to increase, so interoperability between heterogeneous computing elements has become a key area of research. A cyber-physical system (CPS) that has gained a lot of attention lately is a tight integration of the system’s computational and physical elements. The CPS technology builds on the older discipline of embedded systems, and CPS applications can be found in diverse industry sectors, such as smart home, health care, and transportation. There is a high possibility that a global CPS network that integrates different CPS networks appears in the near future. This paper proposes a CPS middleware framework that ensures interoperability and communication between heterogeneous components in a global CPS network. Through local and global communications, the proposed middleware makes mobile devices in different networks interoperable. It employs Internet Protocol version 6 (IPv6) and performs protocol conversion to communicate with devices using different protocols.     

基于移动Agent的Webj服务安全访问机制研究

针对Web服务安全问题中的访问控制，提出将移动Agent引入Web服务的安全访问控制模型，通过SRP协议对Web服务附加了一个独立的访问控制代理层，具有良好的通用性。实现了基于移动Agent的Web服务访问控制模型．并对控制流程进行了描述。     

基于移动Agent的Web服务安全访问机制研究

针对web服务安全问题中的访问控制,提出将移动Agent引入web服务的安全访问控制模型,通过SRP协议对web服务附加了一个独立的访问控制代理层,具有良好的通用性.实现了基于移动Agent的web服务访问控制模型,并对控制流程进行了描述.     

可信移动Agent的研究及在分布式网络管理中的应用

为解决分布式网络管理的安全问题,利用移动Agent框架作为底层平台,应用VMC概念将移动Agent和SNMPAgent相融合,构建一种基于可信移动Agent的安全体系结构。实验结果表明,采用此体系结构的网络管理系统能够确保移动Agent的可信性。因此,该体系结构在受到Agent到Agent平台或Agent到Agent攻击情况下的安全性得到评估,证明在网络管理任务中其性能是可信的。