Overlaying CDMA Systems with Interference Differentials

In the future wideband CDMA cellular systems, services with different data rates, Quality of Service requirements, and power constraints will coexist in a cell. Multiband CDMA may be used to accommodate these heterogeneous service requirements by overlaying the subbands containing different services within the same spectrum band. In this paper we will derive the capacity of multiband CDMA systems in terms of the number of users in each service class, and the corresponding bandwidth utilization. Both reverse and forward links are analyzed. The effects of imperfect power control, other cell interference, and soft handoff are considered. The performance results are compared with the single-band system where all services share the entire system bandwidth.     

通过以太无源光网的射频电视传送技术

论述了1550 nm射频电视(CATV)通道与1490 nm数据通道的相互干扰问题。针对1490 nm光波通过光纤中受激拉曼效应对1550 nm光波的非线性串扰和1550 nm光波通过粗波分复用(CWDM)分波器对1490 nm光波的线性串扰提出了理论计算公式,进行了定量分析和计算。结果表明,数据非线性串扰可使射频电视系统低频端的载噪比下跌9 dB;而在常规融锥型粗波分复用分波器情况下,射频电视线性串扰可使数据光接收机的光功率代价达到2.5dB。最后指出了克服串扰的方法,如以太空闲字符扰码和高隔离度粗波分复用等。     

基于重叠模型的UNI信令研究

采用RSVP-TE信令协议，对重叠网络模型中的UNI信令进行了研究，并对它作了简单的分析，最后在重叠模型的基础上简要描述了通过UNI接口利用RSVP—TE如何实现客户端与网络端之间路径的建立与删除．     

P2P技术原理及应用

对等网络(P2P)有3种主要的组织结构:分布式哈希表(DHT)结构、树形结构、网状结构。P2P技术已经延伸到几乎所有的网络应用领域,如分布式科学计算、文件共享、流媒体直播与点播、语音通信及在线游戏支撑平台等方面。现在人们已经开始将重心转入到覆盖层网络的节点延时聚集研究、覆盖网之间(Inter-Overlay)优化研究、P2P支撑平台研究以及P2P安全研究等方面。     

面向用户需求的信息服务模型

针对广域网络环境下面向用户需求的信息服务要求,给出了一个面向用户信息需求的信息服务模型,并对该模型进行了形式化描述,在此基础上设计了一种基于语义覆盖网络的信息服务体系框架。该框架充分考虑用户的信息需求与信息体系,提供了一种趋于扁平化的信息共享与服务环境。该框架通过自底向上和自顶向下相结合的信息组织模式,基于语义覆盖网络提供信息资源发布、发现与定位的能力。     

Host Mobility Using an Internet Indirection Infrastructure

We propose the Robust Overlay Architecture for Mobility (ROAM) to provide seamless mobility for Internet hosts. ROAM is built on top of the Internet Indirection Infrastructure (i3). With i3, instead of explicitly sending a packet to a destination, each packet is associated with an identifier. This identifier defines an indirection point in i3, and is used by the receiver to obtain the packet. ROAM takes advantage of end-host ability to control the placement of indirection points in i3 to provide efficient routing, fast handoff, and preserve location privacy for mobile hosts. In addition, ROAM allows end hosts to move simultaneously, and is as robust as the underlying IP network to node failure. We have developed a user-level prototype system on Linux that provides transparent mobility without modifying applications or the TCP/IP protocol stack. Simulation results show that ROAM's latency can be as low as 0.25–40% of Mobile IP. Experimental results show that with soft handoff the TCP throughput decreases only by 6% when there are as many as 0.25 handoffs per second. Shelley Zhuang received the B.S. degree in computer engineering and computer science from the University of Missouri-Columbia in 1999, and is now pursuing her Ph.D. degree in computer science at University of California-Berkeley. She has interned at NASA Goddard Space Flight Center, Microsoft, and DaimlerChrysler Research and Technology North America. Her research interest include overlay networking, content distribution networks, streaming media, multicast routing, wireless communications, and network security. Kevin Lai is currently a Scientist at HP Labs. He received his A.B. in Computer Science from U.C.Berkeley and his Ph.D. in Computer Science from Stanford University. Previously he was a post-doctoral scholar in the School of Information Management and Systems (SIMS) and EECS Department at U.C. Berkeley. He has worked on operating systems, mobility, ad hoc networking, network measurement, and incentive systems Ion Stoica received his PhD from the Carnegie Mellon University in 2000. He is an Assistant Professor in the EECS Department at University of California at Berkeley, where he does research on resource management, scalable solutions for end-to-end quality of service, and peer-to-peer network technologies in the Internet. Stoica is the recipient of a Sloan Foundation Fellowship (2003, a National Science Foundation CAREER Award (2002), the ACM doctoral dissertation award (2001), and an Okawa Foundation Fellowship (2001). He is a member of ACM. Randy Howard Katz received his undergraduate degree from Cornell University, and his M.S. and Ph.D. degrees from the University of California, Berkeley. He joined the faculty at Berkeley in 1983, where he is now the United Microelectronics Corporation Distinguished Professor in Electrical Engineering and Computer Science. He is a Fellow of the ACM and the IEEE, and a member of the National Academy of Engineering. He has published over 200 refereed technical papers, book chapters, and books. His hardware design textbook, Contemporary Logic Design, has sold over 85,000 copies worldwide, and has been in use at over 200 colleges and universities. He has supervised 35 M.S. theses and 21 Ph.D. dissertations, and leads a research team of over a dozen graduate students, technical staff, and industrial visitors. He has won numerous awards, including seven best paper awards, one “test of time" paper award, one paper selected for a 50 year retrospective on IEEE communications publications, three best presentation awards, the Outstanding Alumni Award of the Computer Science Division, the CRA Outstanding Service Award, the Berkeley Distinguished Teaching Award, the Air Force Exceptional Civilian Service Decoration, the IEEE Reynolds Johnson Information Storage Award, the ASEE Frederic E. Terman Award, and the ACM Karl V. Karlstrom Outstanding Educator Award. With colleagues at Berkeley, he developed Redundant Arrays of Inexpensive Disks (RAID), a $ 25 billion per year industry sector today. While on leave for government service in 1993–1994, he established whitehouse.gov and connected the White House to the Internet. His current research interests are Internet Services Architecture, Mobile Internet, and the technologies underlying the convergence of telecommunications and packet networks. Prior research interests have included: database management, VLSI CAD, and high performance multiprocessor and storage architectures. Scott Shenker received his degrees, in theoretical physics, from Brown University (Sc. B.) and the University of Chicago (Ph. D.). After a postdoctoral year at Cornell's physics department in 1983, he joined Xerox's Palo Alto Research Center. He left PARC in 1999 to head up a newly established Internet research group at the International Computer Science Institute (ICSI) in Berkeley. Scott's research over the past 15 years has spanned the range from computer performance modeling and computer networks to game theory and economics. Most of his recent work has focused on the Internet architecture and related issues.     

GSM系统的移动智能网技术

介绍ＧＳＭ 系统的移动智能网技术。首先着重对ＧＳＭ Ｐｈａｓｅ２ ＋ 阶段引入的ＣＡＭＥＬ 技术进行讨论,接着简述目前网上采用的过渡方案ＯＶＥＲＬＡＹ 接入方式,最后对第三代移动通信智能网的发展和组网方式提出了作者的一些思考。     

Managing connection costs in heterogeneous wireless networks

Common Radio Resource Management techniques have shown great promise in both enhancing network operation and user satisfication. Such gains are achieved through the joint management of the individual access technologies in a Heterogeneous Wireless Network. The objective of this work is to expand on the existing body of work to accommodate heterogeneity not just at the traditional access‐network level but to other connectivity modes such as dynamic spectrum access. Such modes affect operator profitability in both the long and short terms. Specifically, we explore the design of a cost‐management model that adapts to the short‐term variability in connectivity costs. We also display the operational aspects and effectiveness of this functionality through both simulation and an analytical model. Copyright © 2012 John Wiley & Sons, Ltd.     

基于二维周期结构衍射的套刻测量技术研究

基于衍射光探测的套刻测量技术(DBO)具备高分辨率、高精度及低的工具引起编差(TIS)等显著优点,已逐步取代传统基于成像的套刻测量技术(IBO),成为大规模集成电路22 nm及以下工艺技术节点所广泛采用的套刻测量方式。相较IBO技术,DBO技术面临的最大问题是标记成本高,测量时间长。IBO技术仅需使用单个标记测量x、y两个方向的套刻误差,而DBO则需要分别使用x、y两种方向的一维光栅实现测量,且每个方向至少需要2个标记。提出一种基于二维周期结构标记衍射光探测的套刻测量方法,使用严格耦合波分析(RCWA)算法建立标记衍射光的物理模型,通过分析该方法测量套刻的灵敏度、主要测量误差,验证该方法的可行性。二维DBO测量方法的应用,将使标记成本和测量时间比传统的DBO方法减少一半,显著降低DBO测量的成本并提高测量效率。     

网络虚拟化及网络功能虚拟化技术探讨

对网络虚拟化及网络功能虚拟化的需求及热点技术进行分析,并提出在运营商网络中的典型应用场景:数据中心网络、移动核心网络、家庭网络。数据中心网络虚拟化可灵活实现不同租户的安全、流量、性能策略,实现网络自动配置;演进分组核心网网元虚拟化通过网络功能虚拟化实现不同种类网络硬件架构的统一,解决容量增加带来的成本问题,解决业务灵活部署和增强的问题;家庭网络虚拟化可简化用户侧设备,通过减少用户终端设备的维护和升级进而降低运营成本,并提高业务部署的灵活性。