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71.
文中在分析了超宽带(Ultra-Wideband,UWB)技术特点的基础上,与Ad Hoc网络已有的路由协议结合,提出了一种基于定位辅助和能量有效的超宽带自组网路由算法。仿真表明,该算法能够显著延长网络生存时间,均衡节点电量消耗。 相似文献
72.
Jang-Ping Sheu Chih-Min Chao Wei-Kai Hu Ching-Wen Sun 《Wireless Personal Communications》2007,43(2):185-200
In multihop wireless ad hoc networks, it is important that all mobile hosts are synchronized. Synchronization is necessary
for power management and for frequency hopping spread spectrum (FHSS) operations. IEEE 802.11 standards specify a clock synchronization
protocol but this protocol suffers from the scalability problem due to its inefficiency contention mechanism. In this paper,
we propose an automatic self-time-correcting procedure (ASP) to achieve clock synchronization in a multihop environment. Our
ASP has two features. First, a faster host has higher priority to send its timing information out than a slower one. Second,
after collecting enough timing information, a slower host can synchronize to the faster one by self-correcting its timer periodically
(which makes it becoming a faster host). Simulation results show that our ASP decreases 60% the average maximum clock drift
as compared to the IEEE 802.11 and reduces 99% the number of asynchronism in a large-scale multihop wireless ad hoc networks. 相似文献
73.
In this paper, we propose a novel on-demand energy-aware routing protocol, UBPCR [utility-based power control routing], which
reduces the trade-offs that arise in the other energy-aware route selection mechanisms that have recently been proposed for
mobile ad hoc networks. Our approach is based on an economic framework that represents the degree of link's satisfaction (utility).
With UBPCR, the utility function for any transmitter-receiver pair is defined as a measure of the link's preference regarding
the signal-to-interference-and-noise ratio (SINR), the transmit power, and the transmitter's residual battery capacity. During
a route-searching process, each intermediate node between the source and the destination is executed via two consecutive phases:
the scheduling phase and the transmit power control phase. The scheduling algorithm finds the proper qualified data slot for
the receiving channel so that the transmissions of independent transmitters can be coordinated. The transmit power control
determines the optimal power, if one exists, that maximizes the corresponding link's utility. Extensive simulations show that
the UBPCR protocol can achieve incompatible goals simultaneously and fairly.
Chan-Ho Min received the B.S. degree in Industrial Management and the M.S. degree in Industrial Engineering from Korea Advanced Institute
of Science and Technology (KAIST) in 2000 and 2002, respectively, where he is currently pursuing the doctoral degree in Industrial
Engineering (Telecommunication Engineering Interdisciplinary Program) at KAIST. His research interests include the optimization
problems of radio resource management for broadband wireless/cellular/ad hoc/satellite communication networks. In particular,
he focuses on mobile ad hoc networking.
Sehun Kim received the B.S. degree in Physics from Seoul National University, Seoul, Korea, and the M.S .and Ph.D. degrees in Operations
Research from Stanford University. In 1982, he joined the faculty of the Korea Advanced Institute of Science and Technology
(KAIST), where he is currently a Professor of Industrial Engineering. His research has been in the areas of combinatorial
and nonlinear optimization. Recently, he is working on the application of optimization techniques to the design and analysis
of computer and communication systems. He has published a number of papers in Mathematical Programming, Operations Research
Letters, Journal of Optimization Theory and Applications, IEEE Trans. on Vehicular Technology, and International Journal of
Satellite Communications. 相似文献
74.
In many applications, wireless ad-hoc networks are formed by devices belonging to independent users. Therefore, a challenging
problem is how to provide incentives to stimulate cooperation. In this paper, we study ad-hoc games—the routing and packet forwarding games in wireless ad-hoc networks. Unlike previous work which focuses either on routing
or on forwarding, this paper investigates both routing and forwarding. We first uncover an impossibility result—there does
not exist a protocol such that following the protocol to always forward others' traffic is a dominant action. Then we define a novel solution concept called cooperation-optimal protocols. We present Corsac, a cooperation-optimal protocol which consists of a routing protocol and a forwarding protocol. The routing
protocol of Corsac integrates VCG with a novel cryptographic technique to address the challenge in wireless ad-hoc networks
that a link’s cost (i.e., its type) is determined by two nodes together. Corsac also applies efficient cryptographic techniques to design a forwarding protocol
to enforce the routing decision, such that fulfilling the routing decision is the optimal action of each node in the sense that it brings the maximum utility to the node. We evaluate our protocols using simulations.
Our evaluations demonstrate that our protocols provide incentives for nodes to forward packets. Additionally, we discuss the
challenging issues in designing incentive-compatible protocols in ad hoc networks.
Part of this paper appeared in a conference version [49]. Sheng Zhong was supported in part by NSF grants ANI-0207399 and
CNS-0524030. Yang Richard Yang was supported in part by NSF grants ANI-0207399, ANI-0238038, and CNS-0435201. This work was
partly done while Sheng Zhong was at Yale University; Yanbin Liu was at University of Texas at Austin.
Sheng Zhong is an assistant professor in the State University of New York at Buffalo. He received his PhD (2004) from Yale University
and his ME (1999), BS (1996) from Nanjing University, China, all in computer science. His research interests include economic
incentives and privacy protection, particularly incentive and privacy problems in mobile computing and data mining.
Li Erran Li received his B.E. in Automatic Control from Beijing Polytechnic University in 1993, his M.E. in Pattern Recognition from
the Institute of Automation, Chinese Academy of Sciences, in 1996, and his Ph.D. in Computer Science from Cornell University
in 2001 where Joseph Y. Halpern was his advisor. He is presently a member of the Networking Research Center in Bell Labs.
His research interests are in networking with a focus on wireless networking and mobile computing. He has served as a program
committee member for several conferences including ACM MobiCom, ACM MobiHoc, IEEE INFOCOM and IEEE ICNP. He is a guest editor
for JSAC special issue on Non-Cooperative Behavior in Networking. He has published over 30 papers.
Yanbin Liu received her B.E. degree in Computer Science and Technology from Tsinghua University (1993), Beijing, China, in 1993, and
her M.S. degree in Computer Science from the University of Texas at Austin (1998), where is a Ph.D. candidate. Since 2006,
he has been with IBM TJ Watson Research Center, Hawthorne, NY. Her research interests are in real-time systems, grid computing,
mobile computing, and computer networks.
Yang Richard Yang received his B.E. degree in Computer Science and Technology from Tsinghua University, Beijing, China, in 1993, and his M.S.
and Ph.D. degrees in Computer Science from the University of Texas at Austin in 1998 and 2001, respectively. Since 2001, he
has been with the Department of Computer Science, Yale University, New Haven, CT, where currently he is an Associate Professor.
His current research interests are in computer networks, mobile computing, and sensor networks. He leads the Laboratory of
Networked Systems (LANS) at Yale University. 相似文献
75.
We present a clustering technique addressing redundancy for bounded-distance clusters, which means being able to determine the minimum number of cluster-heads per node, and the maximum distance from nodes to their cluster-heads. This problem is similar to computing a (k, r)-dominating set, (k, r)-DS, of the network. (k, r)-DS is defined as the problem of selecting a minimum cardinality vertex set D of the network such that every vertex u not in D is at a distance smaller than or equal to r from at least k vertices in D. In mobile ad hoc networks (MANETs), clusters should be computed distributively, because the topology may change frequently. We present the first centralized and distributed solutions to the (k, r)-DS problem for arbitrary topologies. The centralized algorithm computes a (k · ln Δ)-approximation, where Δ is the largest cardinality among all r-hop neighborhoods in the network. The distributed approach is extended for clustering applications, while the centralized is used as a lower bound for comparison purposes. Extensive simulations are used to compare the distributed solution with the centralized one. As a case study, we propose a novel multi-core multicast protocol that applies the distributed solution for the election of cores. The new protocol is compared against PUMA, one of the best performing multicast protocols for MANETS. Simulation results show that the new protocol outperforms PUMA on the context of static networks. 相似文献
76.
以非线性编辑系统为基础,探讨网络化非线性编辑的特点、系统组成、工作流程以及管理几个方面,并结合徐州高等师范学校校园电视台的实际情况,详细介绍了这一高效的编辑方式。 相似文献
77.
78.
Nikos Komninos Dimitrios D. Vergados Christos Douligeris 《International Journal of Communication Systems》2007,20(12):1391-1406
An ad hoc network is a collection of nodes that do not need to rely on a predefined infrastructure to keep the network connected. Nodes communicate amongst each other using wireless radios and operate by following a peer‐to‐peer network model. In this article, we propose a multifold node authentication approach for protecting mobile ad hoc networks. The security requirements for protecting data link and network layers are identified and the design criteria for creating secure ad hoc networks using multiple authentication protocols are analysed. Such protocols, which are based on zero‐knowledge and challenge‐response techniques, are presented through proofs and simulation results. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
79.
Ad hoc网络安全与攻击探讨 总被引:6,自引:0,他引:6
介绍了Ad hoc网络的体系结构和特点,分析了其存在的网络安全问题,总结了对Ad hoc网络的多种攻击方法,并提出了几种改善Ad hoc网络安全的策略。 相似文献
80.
A Power Control MAC Protocol for Ad Hoc Networks 总被引:6,自引:0,他引:6
This paper presents a power control MAC protocol that allows nodes to vary transmit power level on a per-packet basis. Several researchers have proposed simple modifications of IEEE 802.11 to incorporate power control. The main idea of these power control schemes is to use different power levels for RTS–CTS and DATA–ACK. Specifically, maximum transmit power is used for RTS–CTS, and the minimum required transmit power is used for DATA–ACK transmissions in order to save energy. However, we show that these schemes can degrade network throughput and can result in higher energy consumption than when using IEEE 802.11 without power control. We propose a power control protocol which does not degrade throughput and yields energy saving. 相似文献