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1.
In order to allow truly spontaneous and infrastructureless networking, autoconfiguration algorithm is needed in the practical usage of most mobile ad hoc networks (MANETs). This paper presents spanning-tree based autoconfiguration for mobile ad hoc networks, a novel approach for the efficient distributed address autoconfiguration. With the help of the spanning tree, the proposed scheme attempts to distribute address resources as balanced as possible at the first beginning. Since each node holds a block of free addresses, a newly joining node can obtain a free address almost immediately. Subnet partitioning and merging are well supported. Finally, analysis and simulation demonstrate that our algorithm outperforms the existing approaches in terms of both communication overhead and configuration latency.  相似文献   

2.
The mobile ad hoc network (MANET) has recently been recognized as an attractive network architecture for wireless communication. Reliable broadcast is an important operation in MANET (e.g., giving orders, searching routes, and notifying important signals). However, using a naive flooding to achieve reliable broadcasting may be very costly, causing a lot of contention, collision, and congestion, to which we refer as the broadcast storm problem. This paper proposes an efficient reliable broadcasting protocol by taking care of the potential broadcast storm problem that could occur in the medium-access level. Existing protocols are either unreliable, or reliable but based on a too costly approach. Our protocol differs from existing protocols by adopting a low-cost broadcast, which does not guarantee reliability, as a basic operation. The reliability is ensured by additional acknowledgement and handshaking. Simulation results do justify the efficiency of the proposed protocol.  相似文献   

3.
PACMAN: passive autoconfiguration for mobile ad hoc networks   总被引:4,自引:0,他引:4  
Mobile ad hoc networks (MANETs) enable the communication between mobile nodes via multihop wireless routes without depending on a communication infrastructure. In contrast to infrastructure-based networks, MANET's support autonomous and spontaneous networking and, thus, should be capable of self-organization and -configuration. This paper presents passive autoconfiguration for mobile ad hoc network (PACMAN), a novel approach for the efficient distributed address autoconfiguration of mobile ad hoc networks. Special features of PACMAN are the support for frequent network partitioning and merging, and very low protocol overhead. This is accomplished by using cross-layer information derived from ongoing routing protocol traffic, e.g., address conflicts are detected in a passive manner based on anomalies in routing protocol traffic. Furthermore, PACMAN assigns Internet protocol (IP) addresses in a way that enables their compression, which can significantly reduce the routing protocol overhead. The performance of PACMAN is analyzed in detail based on various simulation results.  相似文献   

4.
薛咏 《信息技术》2006,30(10):115-119
MANET(Mobile Ad hoc Network)中没有一个永久的中心机构,其网络拓扑结构不断变化,所以必须有一种能够对网络主机地址动态自配置和管理的协议。给出了在MANET中动态地址自配置与管理的方法,不同方案的特点及适应情况,最后对目前Ad hoc网络地址配置研究进行总结和展望。  相似文献   

5.
In vehicular ad hoc networks (VANETs), communication takes place between vehicles to vehicles, the vehicles to the road side units, and vice-versa. The basic purpose of these communications is to share and exchange tremendous amount of data and information. For efficient information sharing, a systematic and structured connection establishment algorithm is needed. In VANETs, each connected node of the network need to be assigned a unique address. Hence, an algorithm is needed for the proper assignment of unique address to all nodes in the network. This paper explains different types of IP address protocols in VANETs. We have also explained advantage and disadvantage of existing IP address allocation protocols in VANETs.  相似文献   

6.
Using directional antennas in wireless mobile ad hoc networks can greatly improve the transmission range as well as the spatial reuse. However, it will also cause some problems such as deafness problem and hidden terminal problem, which greatly impair the network performance. This paper first proposes a MAC protocol called Selectively Directional MAC (SDMAC) that can effectively address these problems and significantly improve the network throughput. Then two improvements on SDMAC are proposed. The first one is to improve the network throughput by scheduling the packets in the queue (a scheme called Q-SDMAC), thus the head-of-line (HOL) blocking problem can be addressed. The second one is to relax the assumption that each node knows the relative directions of its neighboring nodes and use caches to buffer those relative directions (a scheme named Q-SDMAC using cache). Extensive simulations show that: (1) SDMAC can achieve much better performance than the existing MAC protocols using directional antennas; (2) The network throughput can be significantly improved by scheduling the packets in the queue; (3) Using caches can still achieve high network throughput when nodes are moving; and (4) Network throughput decreases when directional antennas have side lobe gain.
Yuguang Fang (Corresponding author)Email:
  相似文献   

7.
A Mobile Ad hoc NETwork (MANET) is a group of mobile nodes that form a multihop wireless network. The topology of the network can change randomly due to unpredictable mobility of nodes and propagation characteristics. Previously, it was assumed that the nodes in the network were assigned IP addresses a priori. This may not be feasible as nodes can enter and leave the network dynamically. A dynamic IP address assignment protocol like DHCP requires centralized servers that may not be present in MANETs. Hence, we propose a distributed protocol for dynamic IP address assignment to nodes in MANETs. The proposed solution guarantees unique IP address assignment under a variety of network conditions including message losses, network partitioning and merging. Simulation results show that the protocol incurs low latency and communication overhead for an IP address assignment.  相似文献   

8.
This letter presents the design and performance of a multi-channel MAC protocol that supports multiple traffics for IEEE 802.11 mobile ad-hoc networks.The dynamic channel selection scheme by receiver decision is implemented and the number of the data channel is independent of the network topology.The priority for real-time traffic is assured by the proposed adaptive back off algorithm and different IFS.The protocol is evaluated by simulation and the results have shown that it can support multiple traffics and the performance is better than the performance that IEEE 802.11 standard provides.  相似文献   

9.
One possibility direction to assist routing in Mobile Ad Hoc Network (MANET) is to use geographical location information provided by positioning devices such as global positioning systems (GPS). Instead of searching the route in the entire network blindly, position-based routing protocol uses the location information of mobile nodes to confine the route searching space into a smaller estimated range. The smaller route searching space to be searched, the less routing overhead and broadcast storm problem will occur. In this paper, we proposed a location-based routing protocol called LARDAR. There are three important characteristics be used in our protocol to improve the performance. Firstly, we use the location information of destination node to predict a smaller triangle or rectangle request zone that covers the position of destination in the past. The smaller route discovery space reduces the traffic of route request and the probability of collision. Secondly, in order to adapt the precision of the estimated request zone, and reduce the searching range, we applied a dynamic adaptation of request zone technique to trigger intermediate nodes using the location information of destination node to redefine a more precise request zone. Finally, an increasing-exclusive search approach is used to redo route discovery by a progressive increasing search angle basis when route discovery failed. This progressive increased request zone and exclusive search method is helpful to reduce routing overhead. It guarantees that the areas of route rediscovery will never exceed twice the entire network. Simulation results show that LARDAR has lower routing cost and collision than other protocols. Tzay-Farn Shih was with Department of Electrical Engineering, National Taiwan University. Tzay-Farn Shih received the B.S. degree in Information Management from Chinese Culture University, Taiwan, in 1992, the M.S. degree in Computer Science Engineering from Tatung University, Taiwan, in 1996, and the Ph.D. degree in Electrical Engineering from National Taiwan University, Taiwan, in 2006. He is presently an assistant professor of Computer Science and Information Engineering at Chaoyang University of Technology, where he initially joined in August 2006. He is currently an overseas member of the Institute of Electronics, Information and Communication Engineers (IEICE). His current research interests include computer simulation, computer networks routing protocol, wireless networks, Mobile Ad Hoc networks and sensor networks. Hsu-Chun Yen was born in Taiwan, Republic of China, on May 29, 1958. He received the B.S. degree in electrical engineering from National Taiwan University, Taiwan, in 1980, the M.S. degree in computer engineering from National Chiao-Tung University, Taiwan, in 1982, and the Ph.D. degree in computer science from the University of Texas at Austin, U.S.A., in 1986. He is presently a Professor of Electrical Engineering at National Taiwan University, where he initially joined in August 1990. From August 1986 to July 1990, he was an Assistant Professor of Computer Science at Iowa State University, Ames, Iowa, U.S.A. His current research interests include Petri net theory, formal methods, design and analysis of algorithms, and complexity theory. Dr. Yen is an editor of International Journal of Foundations of Computer Science (IJFCS, World Scientific Publisher).  相似文献   

10.
面向MANET环境的动态自适应副本放置算法研究   总被引:3,自引:0,他引:3  
移动自组网环境给数据复制技术带来了新的挑战。本文提出了一种分布式动态自适应副本放置算法,算法以数据访问的通信开销作为目标函数,每个副本节点从其邻居节点收集读写请求的局部信息,动态地调整副本放置方案以适应访问请求和网络拓扑的变化。本文还提出了基于稳定邻居的副本放置算法以减小由于节点移动给副本放置带来的振荡。模拟实验表明,在移动自组网环境中,本文提出的算法有效地减少了数据访问的通信开销,提高了数据访问的效率。  相似文献   

11.
We explore applications of quorum systems to the problem of tracking locations of mobile users in mobile ad hoc networks (MANETs). The location tracking system uses biquorum systems, a generalization of traditional quorum systems. We performed extensive simulations of the location tracking system. The simulation results show that our strict biquorum implementation has better performance than the traditional strict quorum implementations. Moreover, our results show that randomized dynamic quorum implementations have better overall performance than strict (bi)quorum implementations.  相似文献   

12.
Secure message transmission in mobile ad hoc networks   总被引:1,自引:0,他引:1  
The vision of nomadic computing with its ubiquitous access has stimulated much interest in the mobile ad hoc networking (MANET) technology. However, its proliferation strongly depends on the availability of security provisions, among other factors. In the open, collaborative MANET environment, practically any node can maliciously or selfishly disrupt and deny communication of other nodes. In this paper, we propose the secure message transmission (SMT) protocol to safeguard the data transmission against arbitrary malicious behavior of network nodes. SMT is a lightweight, yet very effective, protocol that can operate solely in an end-to-end manner. It exploits the redundancy of multi-path routing and adapts its operation to remain efficient and effective even in highly adverse environments. SMT is capable of delivering up to 83% more data messages than a protocol that does not secure the data transmission. Moreover, SMT achieves up to 65% lower end-to-end delays and up to 80% lower delay variability, compared with an alternative single-path protocol––a secure data forwarding protocol, which we term secure single path (SSP) protocol. Thus, SMT is better suited to support quality of service for real-time communications in the ad hoc networking environment. The security of data transmission is achieved without restrictive assumptions on the network nodes’ trust and network membership, without the use of intrusion detection schemes, and at the expense of moderate multi-path transmission overhead only.  相似文献   

13.
Rehan  Turgay  G.V.S.   《Ad hoc Networks》2008,6(7):1134-1150
In mobile ad hoc networks (MANETs) and wireless sensor networks (WSNs), it is easy to launch various sophisticated attacks such as wormhole, man-in-the-middle and denial of service (DoS), or to impersonate another node. To combat such attacks from outsider nodes, we study packet authentication in wireless networks and propose a hop-by-hop, efficient authentication protocol, called HEAP. HEAP authenticates packets at every hop by using a modified HMAC-based algorithm along with two keys and drops any packets that originate from outsiders. HEAP can be used with multicast, unicast or broadcast applications. We ran several simulations to compare HEAP with existing authentication schemes, such as TESLA, LHAP and Lu and Pooch’s algorithm. We measured metrics such as latency, throughput, packet delivery ratio, CPU and memory utilization and show that HEAP performs very well compared to other schemes while guarding against outsider attacks.  相似文献   

14.
Wireless ad hoc networks are growing important because of their mobility, versatility, and ability to work with fewer infrastructures. The mobile ad hoc network is an autonomous system consisting of mobile nodes connected with wireless links. Establishing a path between two nodes is a complex task in wireless networks. It is still more complex in the wireless mobile ad hoc network because every node is no longer as an end node and an intermediate node. In this paper, it focuses on design of connectionless routing protocol for the wireless ad hoc networks based on the mobile agent concept. The proposed model tries to discover the best path taking into consideration some concerns like bandwidth, reliability, and congestion of the link. The proposed model has been simulated and tested under various wireless ad hoc network environments with the help of a different number of nodes. The results demonstrate that the proposed model is more feasible for providing reliable paths between the source and destination with the minimum control message packets over the network. It has delivered more number of packets to the destination over the network. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

15.
In large and dense mobile ad hoc networks, position-based routing protocols can offer significant performance improvement over topology-based routing protocols by using location information to make forwarding decisions. However, there are several potential security issues for the development of position-based routing protocols. In this paper, we propose a secure geographic forwarding (SGF) mechanism, which provides source authentication, neighbor authentication, and message integrity by using both the shared key and the TIK protocol. By combining SGF with the Grid Location Service (GLS), we propose a Secure Grid Location Service (SGLS) where any receiver can verify the correctness of location messages. We also propose a Local Reputation System (LRS) aiming at detecting and isolating both compromised and selfish users. We present the performance analysis of both SGLS and LRS, and compare them with the original GLS. Simulation results show that SGLS can operate efficiently by using effective cryptographic mechanisms. Results also show that LRS effectively detects and isolates message dropping attackers from the network.  相似文献   

16.
The proper functioning of mobile ad hoc networks depends on the hypothesis that each individual node is ready to forward packets for others. This common assumption, however, might be undermined by the existence of selfish users who are reluctant to act as packet relays in order to save their own resources. Such non-cooperative behavior would cause the sharp degradation of network throughput. To address this problem, we propose a credit-based Secure Incentive Protocol (SIP) to stimulate cooperation among mobile nodes with individual interests. SIP can be implemented in a fully distributed way and does not require any pre-deployed infrastructure. In addition, SIP is immune to a wide range of attacks and is of low communication overhead by using a Bloom filter. Detailed simulation studies have confirmed the efficacy and efficiency of SIP. This work was supported in part by the U.S. Office of Naval Research under Young Investigator Award N000140210464 and under grant N000140210554. Yanchao Zhang received the B.E. degree in Computer Communications from Nanjing University of Posts and Telecommunications, Nanjing, China, in July 1999, and the M.E. degree in Computer Applications from Beijing University of Posts and Telecommunications, Beijing, China, in April 2002. Since September 2002, he has been working towards the Ph.D. degree in the Department of Electrical and Computer Engineering at the University of Florida, Gainesville, Florida, USA. His research interests are network and distributed system security, wireless networking, and mobile computing, with emphasis on mobile ad hoc networks, wireless sensor networks, wireless mesh networks, and heterogeneous wired/wireless networks. Wenjing Lou is an assistant professor in the Electrical and Computer Engineering department at Worcester Polytechnic Institute. She obtained her Ph.D degree in Electrical and Computer Engineering from University of Florida in 2003. She received the M.A.Sc degree from Nanyang Technological University, Singapore, in 1998, the M.E degree and the B.E degree in Computer Science and Engineering from Xi'an Jiaotong University, China, in 1996 and 1993 respectively. From Dec 1997 to Jul 1999, she worked as a Research Engineer in Network Technology Research Center, Nanyang Technological University. Her current research interests are in the areas of ad hoc and sensor networks, with emphases on network security and routing issues. Wei Liu received his B.E. and M.E. in Electrical and Information Engineering from Huazhong University of Science and Technology, Wuhan, China, in 1998 and 2001. In August 2005, he received his PhD in Electrical and Computer Engineering from University of Florida. Currently, he is a senior technical member with Scalable Network Technologies. His research interest includes cross-layer design, and communication protocols for mobile ad hoc networks, wireless sensor networks and cellular networks. Yuguang Fang received a Ph.D. degree in Systems Engineering from Case Western Reserve University in January 1994 and a Ph.D degree in Electrical Engineering from Boston University in May 1997. He was an assistant professor in the Department of Electrical and Computer Engineering at New Jersey Institute of Technology from July 1998 to May 2000. He then joined the Department of Electrical and Computer Engineering at University of Florida in May 2000 as an assistant professor, got an early promotion to an associate professor with tenure in August 2003 and a professor in August 2005. He has published over 150 papers in refereed professional journals and conferences. He received the National Science Foundation Faculty Early Career Award in 2001 and the Office of Naval Research Young Investigator Award in 2002. He has served on many editorial boards of technical journals including IEEE Transactions on Communications, IEEE Transactions on Wireless Communications, IEEE Transactions on Mobile Computing and ACM Wireless Networks. He is a senior member of the IEEE.  相似文献   

17.
A mobile ad hoc network (MANET) is a collection of mobile nodes which are able to communicate with each other without relying on predefined infrastructures or central administration. Due to their flexibilities and easy deployment, MANET can be applied in situation where network infrastructures are not available. However, due to their unique characteristics such as open medium and the lack of central administration, they are much more vulnerable to malicious attacks than a conventional infrastructured wireless network. MANET employs routing to provide connectivity for mobile nodes that are not within direct wireless transmission range. Existing routing protocols in MANET assume a trusted and cooperative environment. However, in hostile environment, mobile nodes are susceptible to various kinds of routing attacks. In this paper, we show that an OLSR MANET node is prone to be isolated by malicious attack called Node Isolation attack. After analysing the attack in detail, we present a technique to mitigate the impact of the attack and improve the performance of the network when the attack is launched. The results of our implementations illustrate that the proposed solution can mitigate the attack efficiently. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

18.
Transmission-scheduling protocols can support contention-free link-level broadcast transmissions and delay sensitive traffic in mobile, multiple-hop packet radio networks. Use of transmission-scheduling protocols, however, can be very inefficient in mobile environments due to the difficulty in adapting transmission schedules. The paper defines a new adaptive and distributed protocol that permits a terminal to adapt transmission assignments to changes in topology using information it collects from its local neighborhood only. Because global coordination among all the terminals is not required and changes to transmission assignments are distributed to nearby terminals only, the protocol can adapt quickly to changes in the network connectivity. The two key parameters that affect the ability of the protocol to adapt to changes in connectivity are the rate of connectivity changes and the number of terminals near the connectivity changes. Using simulation, we determine the ranges for these parameters for which our adaptive protocol can maintain collision-free schedules with an acceptable level of overhead. The stability of the protocol is also characterized by showing that the protocol can quickly return to a collision-free transmission schedule after a period of very rapid changes in connectivity. Our channel-access protocol does not require a contention-based random-access phase to adapt the transmission schedules, and thus its ability to adapt quickly does not deteriorate with an increase in the traffic load.  相似文献   

19.
采用博弈论的思想为节点间的间接信任信息获取建立了博弈模型,提出了惩罚机制并给出了节点的效用函数。此外,建立了信任演化的复制动态方程来研究在不同参数下节点的演化稳定策略。通过实验验证了方法的正确性及有效性,证明该模型可使节点为了获得最大利益而在间接信任评估过程中趋于选择同邻居节点合作,从而提高信任管理系统的可用性与有效性,同时验证了节点在不同前提条件下的演化稳定策略。  相似文献   

20.
S.A.  S.M.  N.L.  P.J.   《Ad hoc Networks》2008,6(7):1151-1167
Nowadays, a commonly used wireless network (i.e., Wi-Fi) operates with the aid of a fixed infrastructure (i.e., an access point) to facilitate communication between nodes. The need for such a fixed supporting infrastructure limits the adaptability and usability of the wireless network, especially in situations where the deployment of such an infrastructure is impractical. Recent advancements in computer network introduced a new wireless network, known as a mobile ad hoc network (MANET), to overcome the limitations. Often referred as a peer to peer network, the network does not have any fixed topology, and through its multi hop routing facility, each node can function as a router, thus communication between nodes becomes available without the need of a supporting fixed router or an access point. However, these useful facilities come with big challenges, particularly with respect to providing security. A comprehensive analysis of attacks and existing security measures suggested that MANET are not immune to a colluding blackmail because such a network comprises autonomous and anonymous nodes. This paper addresses MANET security issues by proposing a novel intrusion detection system based upon a friendship concept, which could be used to complement existing prevention mechanisms that have been proposed to secure MANETs. Results obtained from the experiments proved that the proposed concepts are capable of minimising the problem currently faced in MANET intrusion detection system (IDS). Through a friendship mechanism, the problems of false accusations and false alarms caused by blackmail attackers in intrusion detection and response mechanisms can be eliminated.  相似文献   

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