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1.
分析了网络编码系统DCAR"编码+路由"发现过程存在的安全问题,提出了适用于编码感知安全路由协议的安全目标,设计了基于DCAR的编码感知安全路由协议DCASR,DCASR协议利用密码学机制保证可信路由建立和正确编码机会发现。为建模多跳无线网络特征和分析路由协议安全性,引入线程位置和线程位置相邻概念扩展安全系统逻辑LS2,提出了分析路由协议安全性的逻辑LS2-RP。LS2-RP用线程邻居集及邻居集的变化描述多跳无线网络的动态拓扑关系,用广播规则模型化多跳无线网络广播通信特征。最后,用LS2-RP协议编程语言描述了DCASR协议,用LS2-RP的谓词公式和模态公式描述DCASR协议的安全属性,用LS2-RP逻辑证明系统分析了DCASR协议的安全性,证明DCASR协议能够满足安全目标。 相似文献
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Yu Quan Wu Kejun Luo Guoming Jin Yongxin 《电子科学学刊(英文版)》2007,24(3):412-416
A Minimizing Intermediate Multicast Routing protocol (MIMR) is proposed for dynamic multi-hop ad hoc networks. In MIMR, multicast sessions are created and released only by source nodes. In each multicast session process, the source node keeps a list of intermediate nodes and destinations, which is encapsulated into the packet header when the source node sends a multicast packet. Nodes receiving multicast packets decide to accept or forward the packet according to the list. Depending on topology matrix maintained by unicast routing, the shortest virtual hierarchy routing tree is constructed by improved Dijkstra algorithm. MIMR can achieve the minimum number of intermediate nodes, which are computed through the tree. No control packet is transmitted in the process of multicast session. Load of the network is largely decreased. Experimental result shows that MIMR is flexible and robust for dynamic ad hoc networks. 相似文献
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Geometric routing provides a scalable and efficient way to route messages in ad hoc networks if extensive routing information is unavailable. Such algorithms require a planar graph to guarantee message delivery. The routing techniques for such guarantee usually center around the traversal of planar faces of the graph. However, in realistic wireless networks existing planarization methods, if at all applicable, tend to require extensive local storage or result in suboptimal route selection. In this paper we study an alternative approach of translating the algorithms themselves to be able to route messages over voids in non-planar graphs. We prove sufficient memory requirements for such translations. We then translate several well-known planar geometric routing algorithms and evaluate their performance in both static and mobile networks. 相似文献
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CHEN Chao ZHENG Bao-yu ZHAO Xian-jingInstitute of Signal Information Processing Nanjing University of Posts Telecommunications Nanjing China 《中国邮电高校学报(英文版)》2006,13(3):5-10
1 Introduction Ad hoc [1, 2] network is a dynamic-topological mobile self-organized network without any centralized access point. In such a network, each node acts as both host and router simultaneously, entering and departing from the network freely. How… 相似文献
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为了改善无线多跳网络的性能,很多研究表明跨层协议设计比OSI模型更适合无线网络。本文分析了无线多跳网络的特征及对各协议层的影响,给出了跨层协议设计对网络性能的改善以及它可能带来的问题,并针对速率自适应MAC协议和网络层路由协议之间的相互影响给出了仿真实例,结果证明跨层协议设计要充分考虑不同协议之间的相互影响,合理规划、谨慎实施,否则网络的性能不升反降。 相似文献
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随着多跳蜂窝网的发展,协作通信成为热点问题,其中节点激励策略是研究重点.分析比较了Ad Hoc网络和多跳蜂窝网络中的激励策略.根据每种策略的优缺点,详细阐述了实现节点激励策略的关键因素,指出结合信誉和计费和有安全保证的激励策略才是下一代多跳网络节点协作问题的关键. 相似文献
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ZHAO Xian-jing ZHENG Bao-yu CHEN Chao Institute of Signal Information Processing Nanjing University of Posts Telecommunications Nanjing China 《中国邮电高校学报(英文版)》2007,14(1):16-21
A novel weighted cooperative routing algorithm (WCRA) is proposed in this article, which was on the basis of a weighted metric with maximal remaining energy (MRE) of the relays and the maximal received SNR (MRS) of the nodes. Moreover, a cooperative routing protocol was implemented on the basis of WCRA. Then simulation is done on network simulation (NS-2) platform to compare the performances of MRS, MRE and WCRA with that of noncooperative destination-sequenced destination-sequenced distance-vector (DSDV) protocol. The simulative results show that WCRA obtains a performance tradeoff between MRE and MRS in terms of delivery ratio and network lifetime, which can effectively improve the network lifetime at an acceptable loss of delivery ratio. 相似文献
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A key issue impacting the performance of multi-hop wireless networks is the interference among neighboring nodes. In this
paper, we propose a novel and practical interference aware metric, termed as Network Allocation Vector Count (NAVC), to estimate the effects of the interference on the average delay and the available bandwidth. This metric can be easily
applied to routing protocols designed for 802.11 based multi-hop networks with no modification to the current 802.11 protocol.
The design of NAVC as a metric for the AODV [32] routing protocol, as well as a metric for transmit power control, are described
in detail. Our simulation results reveal that the NAVC-driven AODV can greatly improve its performance compared to those protocols
based on hop-count. For scenarios of densely deployed nodes, the throughput improvement is often a factor near two, indicating
that NAVC is more useful as networks grow denser. Moreover, the network lifetime can be notably prolonged when the NAVC is
employed to conduct transmit power control. Our approach is essential for emerging applications such as wireless sensor networks
where the interference is heavy and the energy is severely constrained. 相似文献
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Amir Esmailpour Nidal Nasser Jehad Al Dallal 《International Journal of Communication Systems》2013,26(12):1520-1542
Wireless mesh networks (WMNs) have a proven record in providing viable solutions for some of the fundamental issues in wireless networks such as capacity and range limitations. WMN infrastructure includes clusters of mobile ad‐hoc networks connected through a fixed backbone of mesh routers. The mesh network can be constrained severely because of various reasons, which could result in performance degradation such as a drop in throughput or long delays. Solutions to this problem often focus on multipath or multichannel extensions to the existing ad‐hoc routing protocols. In this paper, we propose a novel solution by introducing an alternative path to the mesh backbone that traverses the mobile ad‐hoc networks part of the WMN. The new routing solution allows the mobile nodes (MNs) to establish direct communication among peers without going through the backbone. The proposed alternative ad‐hoc path is used only when the mesh backbone is severely constrained. We also propose, for the first time in WMNs, using MNs with two interfaces, one used in the mesh backbone communication and the other engaged in the ad‐hoc network. A scheme is presented for making the MN aware of link quality measures by providing throughput values to the ad‐hoc on‐demand distance vector protocol. We use piggybacking on route reply messages in ad‐hoc on‐demand distance vector to avoid incurring additional costs. We implemented our solution in an OPNET simulator and evaluated its performance under a variety of conditions. Simulation results show that the alternative ad‐hoc path provides higher throughput and lower delays. Delay analysis show that the throughput improvement does not impose additional costs. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Improving routing performance in wireless ad hoc networks using cross-layer interactions 总被引:1,自引:0,他引:1
This article presents a combined layer two and three control loop, which allows prediction of link breakage in wireless ad hoc networks. The method monitors the physical layer transmission mode on layer two and exploits the gained knowledge at layer three. The mechanism bases on link adaptation, which is used in IEEE 802.11a WLAN to select the transmission mode according to the link quality. The process of link adaptation contains information that is useful to predict link stability and link lifetime. After introducing the IEEE 802.11a Medium Access Control (MAC) and PHY layer, we present insight to the IEEE 802.11a link adaptation behaviour in multi-hop ad hoc networks. The link adaptation algorithm presented here is derived from Auto Rate Fallback (ARF) algorithm. We survey the performance gain of two newly developed route adaptation approaches exploding the prediction results. One approach is Early Route ReArrangement (ERRA) that starts a route reconstruction procedure before link breakage. Hence, an alternative route is available before connectivity is lost. Early Route Update (ERU) is a complementing approach that enhances this process, by communications among routing nodes surrounding the breaking link. The delay caused by route reconstruction can be significantly reduced if prediction and either of our new route discovery processes is used. 相似文献
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Application layer multicasting has emerged as an appealing alternative to network layer multicasting in wireline networks. Here, we examine the suitability of application layer multicast in ad hoc networks. To this effect, we propose a flexible receiver-driven overlay multicast protocol which we call Application Layer Multicast Algorithm (ALMA). ALMA constructs an overlay multicast tree in a dynamic, decentralized and incremental way. First, ALMA is receiver-driven: the member nodes find their connections according to their needs. Second, it is flexible, and thus, it can satisfy the performance goals and the needs of a wide range of applications. Third, it is highly adaptive: it reconfigures the tree in response to mobility or congestion. In addition, our protocol has the advantages of an application layer protocol: (a) simplicity of deployment, (b) independence from lower layer protocols, and (c) capability of exploiting features such as reliability and security that may be provided by the lower layers. Through extensive simulations, we show that ALMA performs favorably against the currently best application layer and network layer protocols. In more detail, we find that ALMA performs significantly better than ODMRP, a network layer, for small group sizes. We conclude that the application layer approach and ALMA seem very promising for ad hoc multicasting. 相似文献
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Aiming at the serious impact of the typical network attacks caused by the limited energy and the poor deployment environment of wireless sensor network (WSN) on data transmission,a trust sensing based secure routing mechanism (TSSRM) with the lightweight characteristics and the ability to resist many common attacks simultaneously was proposed.Based on the analysis of the characteristics of network attack,the trust degree calculation model was constructed by combining node’s behavior with energy,at the same time the security route selection algorithm was also optimized by taking trust degree and QoS metrics into account.Performance analysis and simulation results show that TSSRM can improve the security and effectiveness of WSN. 相似文献
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针对典型的时间同步算法应用到多跳拓扑网络时存在时间同步精确度差、收敛速度慢、功耗较大等问题,文章提出一种基于分簇的多跳无线传感网络时间同步算法。该算法结合了TPSN算法和RBS算法的同步思想,摒弃了TPSN算法同步周期长的缺点而保留了其同步精确度高的优点,也解决了RBS同步开销大和难于应用到多跳网络的问题。该算法具有相当高的同步精度,并有效降低了同步功耗,具有一定的实用性。 相似文献
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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
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后压路由算法在投递数据时并不会考虑能耗对节点和网络的影响,这就导致后压路由算法的网络生存时间较短。为解决此问题,基于跨层优化方法建立能耗约束,一种低能耗的后压路由算法被提出。此算法能够自适应地选择能耗较低的下一跳节点投递数据,推迟了节点因能量耗尽而离开网络的时间。实验证明,所提算法与传统后压路由算法相比,能够有效地延长网络生存时间。 相似文献
19.
Robust position-based routing for wireless ad hoc networks 总被引:1,自引:0,他引:1
We consider a wireless ad hoc network composed of a set of wireless nodes distributed in a two dimensional plane. Several routing protocols based on the positions of the mobile hosts have been proposed in the literature. A typical assumption in these protocols is that all wireless nodes have uniform transmission regions modeled by unit disk centered at each wireless node. However, all these protocols are likely to fail if the transmission ranges of the mobile hosts vary due to natural or man-made obstacles or weather conditions. These protocols may fail because either some connections that are used by routing protocols do not exist, which effectively results in disconnecting the network, or the use of some connections causes livelocks. In this paper, we describe a robust routing protocol that tolerates up to roughly 40% of variation in the transmission ranges of the mobile hosts. More precisely, our protocol guarantees message delivery in a connected ad hoc network whenever the ratio of the maximum transmission range to the minimum transmission range is at most . 相似文献
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Secure routing in mobile wireless ad hoc networks 总被引:3,自引:0,他引:3
We discuss several well known contemporary protocols aimed at securing routing in mobile wireless ad hoc networks. We analyze each of these protocols against requirements of ad hoc routing and in some cases identify fallibilities and make recommendations to overcome these problems so as to improve the overall efficacy of these protocols in securing ad hoc routing, without adding any significant computational or communication overhead. 相似文献