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1.
Mobile ad hoc networks are characterized by multi-hop wireless links, absence of any cellular infrastructure, and frequent host mobility. Design of efficient routing protocols in such networks is a challenging issue. A class of routing protocols called on-demand protocols has recently found attention because of their low routing overhead. We propose a technique that can reduce the routing overhead even further. The on-demand protocols depend on query floods to discover routes whenever a new route is needed. Our technique utilizes prior routing histories to localize the query flood to a limited region of the network. Simulation results demonstrate excellent reduction of routing overheads with this mechanism. This also contributes to a reduced level of network congestion and better end-to-end delay performance of data packets.  相似文献   

2.
Lou  Wenjing  Fang  Yuguang 《Wireless Networks》2002,8(6):671-679
Route caching strategy is important in on-demand routing protocols in wireless ad hoc networks. While high routing overhead usually has a significant performance impact in low bandwidth wireless networks, a good route caching strategy can reduce routing overheads by making use of the available route information more efficiently. In this paper, we first study the effects of two cache schemes, link cache and path cache, on the performance of on-demand routing protocols through simulations based on the Dynamic Source Routing (DSR) protocol. Since the path cache DSR has been extensively studied, we focus in this paper on the link cache DSR in combination with timer-based stale link expiry mechanisms. The effects of different link lifetime values on the performance of routing protocol in terms of routing overhead, packet delivery ratio and packet latency are investigated. A caching strategy incorporating adaptive link timeout is then proposed, which aims at tracking the optimal link lifetime under various node mobility levels by adaptively adjusting the link lifetime based on the real link lifetime statistics. The performance of the proposed strategy is then compared with the conventional path cache DSR. The results show that without a timeout mechanism, a link cache scheme may suffer severe performance degradation due to the use of broken routes, while the proposed adaptive link cache strategy achieves significantly improved performance by reducing the routing overhead when the network traffic load is high.  相似文献   

3.
Ad hoc网络的特征是多跳的无线连接,网络拓扑的频繁变化,以及需要有效的动态路由协议。重点比较Ad hoc网络中两种主要的按需路由协议:动态源路由(DSR)协议和Ad hoc按需距离矢量路由(AODV)协议。尽管DSR和AODV都是按需路由协议,但不同的协议机制导致了网络性能的显著差异。在OPNET仿真平台下,对采用不用路由协议的网络时延和吞吐量进行比较,从而分析不同的路由机制引起的网络性能差异。  相似文献   

4.
A mobile ad hoc network (or manet) is a group of mobile, wireless nodes which cooperatively form a network independent of any fixed infrastructure or centralized administration. In particular, a manet has no base stations: a node communicates directly with nodes within wireless range and indirectly with all other nodes using a dynamically-computed, multi-hop route via the other nodes of the manet.Simulation and experimental results are combined to show that energy and bandwidth are substantively different metrics and that resource utilization in manet routing protocols is not fully addressed by bandwidth-centric analysis. This report presents a model for evaluating the energy consumption behavior of a mobile ad hoc network. The model was used to examine the energy consumption of two well-known manet routing protocols. Energy-aware performance analysis is shown to provide new insights into costly protocol behaviors and suggests opportunities for improvement at the protocol and link layers.  相似文献   

5.
Ariadne: A Secure On-Demand Routing Protocol for Ad Hoc Networks   总被引:9,自引:0,他引:9  
An ad hoc network is a group of wireless mobile computers (or nodes), in which individual nodes cooperate by forwarding packets for each other to allow nodes to communicate beyond direct wireless transmission range. Prior research in ad hoc networking has generally studied the routing problem in a non-adversarial setting, assuming a trusted environment. In this paper, we present attacks against routing in ad hoc networks, and we present the design and performance evaluation of a new secure on-demand ad hoc network routing protocol, called Ariadne. Ariadne prevents attackers or compromised nodes from tampering with uncompromised routes consisting of uncompromised nodes, and also prevents many types of Denial-of-Service attacks. In addition, Ariadne is efficient, using only highly efficient symmetric cryptographic primitives.  相似文献   

6.
A mobile ad hoc network (MANET) is characterized by multi-hop wireless links and frequent node mobility. Communication between non-neighboring nodes requires a multi-hop routing protocol to establish a route. But, the route often breaks due to mobility. The source must rediscover a new route for delivering the data packets. This wastes the resources that are limited in MANET. In this paper, a new on-demand routing protocol is proposed, named on-demand routing protocol with backtracking (ORB), for multi-hop mobile ad hoc networks. We use the multiple routes and cache data technique to reduce the rediscovery times and overhead. After executing the route discovery phase, we find out a set of nodes, named checkpoint, which has the multiple routes to the destination. When a checkpoint node receives a data packet, it caches this data packet in its buffer within a specific time period. When a node detects a broken route during the data packets delivery or receives an error packet, it will either recover the broken route or reply the error packet to the source. If a node can not forward the data packet to the next node, it replies an error packet to the source. This packet is backtracking to search a checkpoint to redeliver the data packet to the destination along other alternate routes. The main advantage of ORB is to reduce the flooding search times, maybe just delay and cost while a route has broken. The experimental results show that the proposed scheme can increase the performance of delivery but reduce the overhead efficiently comparing with that of AODV based routing protocols. Hua-Wen Tsai received the B.S. degree in Information Management from Chang Jung Christian University, Taiwan, in June 1998 and the M.B.A. degree in Business and Operations Management from Chang Jung Christian University, Taiwan, in June 2001. Since September 2001, he has been working towards the Ph.D. degree and currently is a doctoral candidate in the Department of Computer Science and Information Engineering, National Cheng Kung University, Taiwan. His research interests include wireless communication, ad hoc networks, and sensor networks. Tzung-Shi Chen received the B.S. degree in Computer Science and Information Engineering from Tamkang University, Taiwan, in June 1989 and the Ph.D. degree in Computer Science and Information Engineering from National Central University, Taiwan, in June 1994. He joined the faculty of the Department of Information Management, Chung Jung University, Tainan, Taiwan, as an Associate Professor in June 1996. Since November 2002, he has become a Full Professor at the Department of Information Management, Chung Jung University, Tainan, Taiwan. He was a visiting scholar at the Department of Computer Science, University of Illinois at Urbana-Champaign, USA, from June to September 2001. He was the chairman of the Department of Information Management at Chung Jung University from August 2000 to July 2003. Since August 2004, he has become a Full Professor at the Department of Information and Learning Technology, National University of Tainan, Tainan, Taiwan. Currently, he is the chairman of the Department of Information and Learning Technology, National University of Tainan. He co-received the best paper award of 2001 IEEE ICOIN-15. His current research interests include mobile computing and wireless networks, mobile learning, data mining, and pervasive computing. Dr. Chen is a member of the IEEE Computer Society. Chih-Ping Chu received the B.S. degree in agricultural chemistry from National Chung Hsing University, Taiwan, the M.S. degree in computer science from the University of California, Riverside, and the Ph.D. degree in computer science from Louisiana State University. He is currently a Professor in the Department of Computer Science and Information Engineering of National Cheng Kung University, Taiwan. His current research interests include parallel computing, parallel processing, component-based software development, and internet computing.  相似文献   

7.
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   

8.
Performance Evaluation of Routing Protocols for Ad Hoc Wireless Networks   总被引:2,自引:1,他引:2  
A mobile ad hoc network is a collection of autonomous mobile nodes that communicate with each other over wireless links. Such networks are expected to play an increasingly important role in future civilian and military settings, being useful for providing communication support where no fixed infrastructure exists or the deployment of a fixed infrastructure is not economically profitable and movement of communicating parties is possible. However, since there is no stationary infrastructure such as base stations, mobile hosts need to operate as routers in order to maintain the information about the network connectivity. Therefore, a number of routing protocols have been proposed for ad hoc wireless networks. In this paper, we study and compare the performance of the following routing protocols AODV, PAODV (preemptive AODV), CBRP, DSR, and DSDV. A variety of workload and scenarios, as characterized by mobility, load and size of the ad hoc network were simulated. Our results indicate that despite its improvement in reducing route request packets, CBRP has a higher overhead than DSR because of its periodic hello messages while AODV's end-to-end packet delay is the shortest when compared to DSR and CBRP. PAODV has shown little improvements over AODV.  相似文献   

9.
ABRP: Anchor-based Routing Protocol for Mobile Ad Hoc Networks   总被引:2,自引:0,他引:2  
Ad hoc networks, which do not rely on any infrastructure such as access points or base stations, can be deployed rapidly and inexpensively even in situations with geographical or time constraints. Ad hoc networks are attractive in both military and disaster situations and also in commercial uses like sensor networks or conferencing. In ad hoc networks, each node acts both as a router and as a host. The topology of an ad hoc network may change dynamically, which makes it difficult to design an efficient routing protocol. As more and more wireless devices connect to the network, it is important to design a scalable routing protocol for ad hoc networks. In this paper, we present Anchor-based Routing Protocol (ABRP), a scalable routing protocol for ad hoc networks. It is a hybrid routing protocol, which combines the table-based routing strategy with the geographic routing strategy. However, GPS (Global Positioning System) (Kaplan, Understanding GPS principles and Applications, Boston: Artech House publishers, 1996) support is not needed. ABRP consists of a location-based clustering protocol, an intra-cell routing protocol and an inter-cell routing protocol. The location-based clustering protocol divides the network region into different cells. The intra-cell routing protocol routes packets within one cell. The inter-cell routing protocol is used to route packets between nodes in different cells. The combination of intra-cell and inter-cell routing protocol makes ABRP highly scalable, since each node needs to only maintain routes within a cell. The inter-cell routing protocol establishes multiple routes between different cells, which makes ABRP reliable and efficient. We evaluate the performance of ABRP using ns2 simulator. We simulated different size of networks from 200 nodes to 1600 nodes. Simulation results show that ABRP is efficient and scales well to large networks. ABRP combines the advantages of multi-path routing strategy and geographic routing strategy—efficiency and scalability, and avoids the burden—GPS support.  相似文献   

10.
移动自组网是由一组带有无线收发装置的移动节点组成的一个多跳的临时性的自治系统。随着无线通信中多媒体业务的增加,在移动自组网中提供QoS(Quality of Sevice服务质量)保障具有越来越重要的意义,而QoS路由技术则是其中的核心技术和热点问题。文章指出移动自组网QoS路由的困难,对移动自组网典型QoS路由协议进行了详细的分析与比较,并对几种较新的移动自组网QoS路由协议进行了介绍,末了对移动自组网QoS路由协议的发展进行了展望。  相似文献   

11.
无线adhoc网络中的多径源路由   总被引:20,自引:0,他引:20  
舒炎泰  高德云  王雷 《电子学报》2002,30(2):279-282
本文针对无线ad hoc网络提出了一种基于DSR(动态源路由)的路由算法,多径源路由(MSR).MSR对DSR中的路由搜索和路由维护机制进行了扩展,用来解决多径路由问题.本文还提出,在多条路径之间基于测量的RTT进行负载分配.仿真结果表明,MSR在只增加少量网络开销的情况下,提高了TCP和UDP的投递率,降低了丢包率,并减少了端到端之间的延迟以及队列长度,从而有效地减少了网络拥塞.  相似文献   

12.
移动ad hoe网络中通信终端能量有限,但在许多应用场景,尤其是战场环境下,节点能量消耗较大,因此采用有效的功率控制策略非常重要.利用信道增益的对称性,在AODV协议的基础上提出了一种不依赖于地理位置信息的跨层功率控制路由协议PBAODV,仿真表明该协议在不影响其他网络性能指标的前提下,有效的降低了系统整体功耗.  相似文献   

13.
The main purposes of this article are to relieve broadcast problem, to immunize to some prerequisites, and to reduce the number of transmitted control packets. Broadcasting control packets network-wide is the most direct and common method for finding the required destination node in ad hoc mobile wireless networks; however, this causes a lot of waste of wireless bandwidth. To remedy the problem, routing protocols demanding some prerequisites are proposed; nonetheless, hardly can they be used if these prerequisites are missed or become stale. To efficiently reduce the number of transmitted control packets, our routing protocol partitions the network into interlaced gray districts and white districts by the aid of GPS and inhibits an intermediate node residing in a white district from re-transmitting the received control packets. However, a mobile node residing in a gray district is responsible for re-transmitting them till they reach the destination node. Our routing protocol does not demand any prerequisite except the use of GPS. Each mobile node can always obtain its own location information; furthermore, the information may neither be missed nor become stale. Our routing protocol is easy to be implemented, saves precious wireless bandwidth, and reduces almost half a number of control packets as compared with pure flooding routing protocols.Ying-Kwei Ho received the B.S. degree and M.S. degree in applied mathematics and in electrical engineering from the Chung-Cheng Institute of Technology in 1987 and 1993 respectively and the Ph.D. degree in computer engineering and science from the Yuan-Ze University, Taiwan, R.O.C. He joined the Army of Taiwan, R.O.C. in 1987 and worked as a software engineer. From 1993 to 1997, he was an instructor in the War Game Center of Armed Forces University, Taiwan, R.O.C. He is currently an assistant professor of the Department of Computer Science at Chung-Cheng Institute of Technology. His research interests include mobile computing, wireless network performance simulation and evaluation, and modeling and simulation.Ru-Sheng Liu received the B.S. degree in electrical engineering from the National Cheng-Kung University, Taiwan, in 1972 and the M.S. and Ph.D. degrees in computer science from the University of Texas at Dallas, Richardson, Texas, in 1981 and1985, respectively. He is currently an associate professor in the Department of Computer Engineering and Science at Yuan-Ze University, Chungli, Taiwan. His research interests are in the areas of mobile computing, internet technology, and computer algorithms.  相似文献   

14.
一种节省能量的移动Ad Hoc网络组播选路协议   总被引:9,自引:0,他引:9  
鉴于现有基于网孔的移动Ad Hoc网络组播选路协议都滑考虑如何有效使用电池能量的问题,本文提出了一种节省能量组播选路协议(E^2MRP),E^2MRP协议的两个主要特征是:(1)在创建和维护中继组(RG)的过程中交替采用分组平均能量消耗最少和最大节点花费最小两种标准,(2)采用基于图的组播结构,本文通过仿真分析大大降低了节点的能量消耗,特别是在节移动性较低,组播成员较少时更是如此。  相似文献   

15.
一种基于迁移可测度的移动自组织网路由模型   总被引:1,自引:0,他引:1  
居熙  陶军  陆一飞  夏勤  王萃寒 《电子学报》2010,38(6):1344-1348
 本文利用链路状态有效估测端到端路径的可达性。路由模型给出最近时间内,任意两点分组传输的迁移可测度;节点根据其邻节点的迁移可测度制定组合策略,计算组合迁移可测度,选取最优中继组合完成分组传输。仿真实验表明,该路由模型既可有效控制分组副本数目,又可获得较高的分组到达率。  相似文献   

16.
Channel Adaptive Shortest Path Routing for Ad Hoc Networks   总被引:6,自引:2,他引:6  
1 IntroductionAdhocnetworksareformedwithoutrequiringthepreexistinginfrastructureorcentralizedadminis tration ,incontrasttocellularnetworks.Asidefromtheoriginalmilitaryapplication ,ithasapplicationinpublicsafetyandcommercialareas,butadaptiveprotocolsarerequiredinorderforthemtodoso .Twoimportantcharacteristicsofacommunicationlinkinadhocnetworksareitsunreliabilityanditsvariability .Thelinksinsuchanetworkareunreli ablebecauseoffading ,interference,noise,andper hapsthefailureofthetransmittingorrec…  相似文献   

17.
Geocasting is a variation on the notion of multicasting. A geographical area is associated with each geocast, and the geocast is delivered to the nodes within the specified geographical area. Thus, geocasting may be used for sending a message that is likely to be of interest to everyone in a specified area. In this paper, we propose three geocasting protocols for ad hoc networks, obtained as variations of a multicast flooding algorithm, and then evaluate these approaches by means of simulations. Proposed geocasting algorithms attempt to utilize physical location information to decrease the overhead of geocast delivery.  相似文献   

18.
Fuzzy Logic QoS Dynamic Source Routing for Mobile Ad Hoc Networks   总被引:1,自引:0,他引:1  
Considering the characters of dynamic topology and the imprecise state information in mobile ad hoc network,we propose a Fuzzy Logic QoS Dynamic Source Routing(FLQDSR)algorithm based on Dynamic Source Routing(DSR)protocol while adopting fuzzy logic to select the appropriate QoS routing in multiple paths which are searched in parallel.This scheme considers not only the bandwidth and end-to-end delay of routing,but also the cost of the path.On the otherhand the merit of using fuzzy logic is that it can be implemented by hardware.This makes the realization of the schemeeasier and faster.However our algorithm is based on DSR,the maximal hop count should be less than 10,i.e.,the scaleof mobile ad hoc network should not be very large.Simulation results show that FLQDSR can tolerate a high degree of in-formation imprecision by adding the fuzzy logic module which integrates the QoS requirements of application and the rout-ing QoS parameters to determine the most qualified one in every node.  相似文献   

19.
This paper presents the design and evaluation of a highly efficient on-demand multicast routing protocol for mobile ad hoc networks (MANETs). The protocol, called Geography-aided Multicast Zone Routing Protocol (GMZRP), eliminates as much as possible duplicate route queries by using a simple yet effective strategy for propagating the multicast route request (MRREQ) packets. GMZRP is the first hybrid multicast protocol taking the advantages of both topological routing and geographical routing. It partitions the network coverage area into small zones and guarantees that each geographic zone is queried only once. GMZRP maintains a multicast forwarding tree at two levels of granularities, i.e., the zone granularity and the node granularity. By doing this, it can easily handle route breakage since the zone level information can help recover the link failure at the node level. The results of the performance evaluation of GMZRP using simulation show that, comparing with the well-known multicast protocol ODMRP (On-Demand Multicast Routing Protocol), GMZRP has much lower protocol overhead in terms of query packets and, meanwhile, achieves competing packet delivery ratio and shorter delivery latency.
Xiaopeng FanEmail:
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20.
孙宝林  桂超  宋莺 《中国通信》2011,8(7):75-83
This paper provides a critical review of energy entropy theory in Mobile Ad Hoc Networks (MANETs) and proposes an Energy Entropy on Ad Hoc On-demand Distance Vector Multipath (EEAODVM) routing protocol. The essential idea of the protocol is to find every route which can minimize the node residual energy in the process of selecting path. It balances individual node battery energy utilization and hence prolongs the entire network lifetime. The results of simulation show that, with the proposed EEAODVM routing...  相似文献   

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