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Showing papers on "Ad hoc On-Demand Distance Vector Routing published in 2007"


Journal ArticleDOI
TL;DR: This paper uses empirical vehicle traffic data measured on 1-80 freeway in California to develop a comprehensive analytical framework to study the disconnected network phenomenon and its network characteristics, and shows that, depending on the sparsity of vehicles or the market penetration rate of cars using Dedicated Short Range Communication technology, the network re-healing time can vary from a few seconds to several minutes.
Abstract: A vehicular ad hoc network (VANET) may exhibit a bipolar behavior, i.e., the network can either be fully connected or sparsely connected depending on the time of day or on the market penetration rate of the wireless communication devices. In this paper, we use empirical vehicle traffic data measured on 1-80 freeway in California to develop a comprehensive analytical framework to study the disconnected network phenomenon and its network characteristics. These characteristics shed light on the key routing performance metrics of interest in disconnected VANETs, such as the average time taken to propagate a packet to disconnected nodes (i.e., the re-healing time). Our results show that, depending on the sparsity of vehicles or the market penetration rate of cars using Dedicated Short Range Communication (DSRC) technology, the network re-healing time can vary from a few seconds to several minutes. This suggests that, for vehicular safety applications, a new ad hoc routing protocol will be needed as the conventional ad hoc routing protocols such as Dynamic Source Routing (DSR) and Ad Hoc On-Demand Distance Vector Routing (AODV) will not work with such long re-healing times. In addition, the developed analytical framework and its predictions provide valuable insights into the VANET routing performance in the disconnected network regime.

534 citations


01 Jan 2007
TL;DR: In this paper, the authors investigate the state-of-the-art of security issues in MANET and examine routing attacks, such as link spoofing and colluding misrelay attacks, as well as countermeasures against such attacks.
Abstract: Recently, mobile ad hoc networks became a hot research topic among researchers due to their flexibility and independence of network infrastructures, such as base stations. Due to unique characteristics, such as dynamic network topology, limited bandwidth, and limited battery power, routing in a MANET is a particularly challenging task compared to a conventional network. Early work in MANET research has mainly focused on developing an efficient routing mechanism in such a highly dynamic and resource-constrained network. At present, several efficient routing protocols have been proposed for MANET. Most of these protocols assume a trusted and cooperative environment. However, in the presence of malicious nodes, the networks are vulnerable to various kinds of attacks. In MANET, routing attacks are particularly serious. In this article, we investigate the state-of-the-art of security issues in MANET. In particular, we examine routing attacks, such as link spoofing and colluding misrelay attacks, as well as countermeasures against such attacks in existing MANET protocols.

474 citations


Journal Article
TL;DR: An anomaly detection scheme using dynamic training method in which the training data is updated at regular time intervals is proposed and the simulation results show the effectiveness of the scheme compared with conventional scheme.
Abstract: This paper analyzes the blackhole attack which is one of the possible attacks in ad hoc networks. In a blackhole attack, a malicious node impersonates a destination node by sending a spoofed route reply packet to a source node that initiates a route discovery. By doing this, the malicious node can deprive the traffic from the source node. In order to prevent this kind of attack, it is crucial to detect the abnormality occurs during the attack. In conventional schemes, anomaly detection is achieved by defining the normal state from static training data. However, in mobile ad hoc networks where the network topology dynamically changes, such static training method could not be used efficiently. In this paper, we propose an anomaly detection scheme using dynamic training method in which the training data is updated at regular time intervals. The simulation results show the effectiveness of our scheme compared with conventional scheme.

453 citations


Proceedings ArticleDOI
11 Jun 2007
TL;DR: Simulation results show that PREP outperforms AODV and Epidemic Routing by a factor of about 4 and 1.4 respectively, with the gap widening with decreasing density and decreasing storage.
Abstract: We describe PRioritized EPidemic (PREP) for routing in opportunistic networks. PREP prioritizes bundles based on costs to destination, source, and expiry time. Costs are derived from per-link "average availability" information that is disseminated in an epidemic manner. PREP maintains a gradient of replication density that decreases with increasing distance from the destination. Simulation results show that PREP outperforms AODV and Epidemic Routing by a factor of about 4 and 1.4 respectively, with the gap widening with decreasing density and decreasing storage. We expect PREP to be of greater value than other proposed solutions in highly disconnected and mobile networks where no schedule information or repeatable patterns exist.

334 citations


Proceedings ArticleDOI
11 May 2007
TL;DR: The first complete version of a multi-hop broadcast protocol for vehicular ad hoc networks (VANET) is reported and it is shown that the broadcast message can be disseminate efficiently and the proposed design of the distributed vehicular broadcast (DV-CAST) protocol integrates the use of various routing solutions.
Abstract: In this paper, we report the first complete version of a multi-hop broadcast protocol for vehicular ad hoc networks (VANET). Our results clearly show that broadcasting in VANET is very different from routing in mobile ad hoc networks (MANET) due to several reasons such as network topology, mobility patterns, demographics, traffic patterns at different times of the day, etc. These differences imply that conventional ad hoc routing protocols such as DSR and AODV will not be appropriate in VANETs for most vehicular broadcast applications. We identify three very different regimes that a vehicular broadcast protocol needs to work in: i) dense traffic regime; ii) sparse traffic regime; and iii) regular traffic regime. We build upon our previously proposed routing solutions for each regime and we show that the broadcast message can be disseminate efficiently. The proposed design of the distributed vehicular broadcast (DV-CAST) protocol integrates the use of various routing solutions we have previously proposed.

322 citations


Book ChapterDOI
01 Jan 2007
TL;DR: This paper classify the architectures for intrusion detection systems (IDS) that have been introduced for MANETs, and current IDS corresponding to those architectures are reviewed and compared and provide some directions for future research.
Abstract: In recent years, the use of mobile ad hoc networks (MANETs) has been widespread in many applications, including some mission critical applications, and as such security has become one of the major concerns in MANETs. Due to some unique characteristics of MANETs, prevention methods alone are not sufficient to make them secure; therefore, detection should be added as another defense before an attacker can breach the system. In general, the intrusion detection techniques for traditional wireless networks are not well suited for MANETs. In this paper, we classify the architectures for intrusion detection systems (IDS) that have been introduced for MANETs. Current IDS ’s corresponding to those architectures are also reviewed and compared. We then provide some directions for future research.

299 citations


Proceedings ArticleDOI
21 May 2007
TL;DR: Evaluating the performance of reactive (AODV, DSR) and proactive (OLSR) routing protocols in MANETs under CBR traffic with different network conditions shows the superiority of proactive over reactive protocols in routing such traffic at the cost of a higher routing load.
Abstract: The mobility of nodes in mobile ad hoc networks (MANETs) results in frequent changes of network topology making routing in MANETs a challenging task. Some studies have been reported in the literature to evaluate the performance of the proposed routing algorithms. However, since the publication of experimental standards for some routing protocols by IETF, little activity has been done to contrast the performance of reactive against proactive protocols. This paper evaluates the performance of reactive (AODV, DSR) and proactive (OLSR) routing protocols in MANETs under CBR traffic with different network conditions. Our results, contrarily to previously reported studies conducted on the same routing protocols, show the superiority of proactive over reactive protocols in routing such traffic at the cost of a higher routing load.

260 citations


Proceedings ArticleDOI
27 Aug 2007
TL;DR: Computer simulation using glomosim shows that the proposed protocol provides better performance than the conventional AODV in the presence of Black holes with minimal additional delay and Overhead.
Abstract: An ad hoc network is a collection of mobile nodes that dynamically form a temporary network. It operates without the use of existing infrastructure. One of the principal routing protocols used in ad-hoc networks is AODV (ad-hoc on demand distance vector) protocol. The security of the AODV protocol is compromised by a particular type of attack called 'black hole' attack. In this attack a malicious node advertises itself as having the shortest path to the node whose packets it wants to intercept. To reduce the probability it is proposed to wait and check the replies from all the neighboring nodes to find a safe route. Computer simulation using glomosim shows that our protocol provides better performance than the conventional AODV in the presence of Black holes with minimal additional delay and Overhead.

258 citations


Proceedings ArticleDOI
06 Dec 2007
TL;DR: This paper evaluates the proposed solution to identifying and preventing the cooperative black hole attack, and presents good performance in terms of better throughput rate and minimum packet loss percentage over other solutions, and can accurately prevent the Cooperative black hole attacks.
Abstract: A black hole attack is a severe attack that can be easily employed against routing in mobile ad hoc networks. A black hole is a malicious node that falsely replies for any route requests without having active route to specified destination and drops all the receiving packets. If these malicious nodes work together as a group then the damage will be very serious. This type of attack is called cooperative black hole attack. In S. Ramaswamy et al. (2003), we proposed a solution to identifying and preventing the cooperative black hole attack. Our solution discovers the secure route between source and destination by identifying and isolating cooperative black hole nodes. In this paper, via simulation, we evaluate the proposed solution and compare it with other existing solutions in terms of throughput, packet loss percentage, average end-to-end delay and route request overhead. The experiments show that (1) the AODV greatly suffers from cooperative black holes in terms of throughput and packet losses, and (2) our solution proposed in S. Ramaswamy et al. (2003) presents good performance in terms of better throughput rate and minimum packet loss percentage over other solutions, and (3) our solution can accurately prevent the cooperative black hole attacks. The example findings are: (1) the proposed scheme presents 5 - 8% more communication overhead of route request; and (2) The secure route discovery delay slightly increases the packet loss percentage.

171 citations


Proceedings ArticleDOI
01 May 2007
TL;DR: This work develops a statistical traffic model based on the data collected on 1-80 freeway in California in order to study key performance metrics of interest in disconnected VANETs, such as average re-healing time (or the network restoration time).
Abstract: Vehicular ad hoc wireless network (VANET) exhibits a bipolar behavior in terms of network topology: fully connected topology with high traffic volume or sparsely connected topology when traffic volume is low. In this work, we develop a statistical traffic model based on the data collected on 1-80 freeway in California in order to study key performance metrics of interest in disconnected VANETs, such as average re-healing time (or the network restoration time). Our results show that, depending on the sparsity of vehicles, the network re-healing time can vary from a few seconds to several minutes. This suggests that, a new ad hoc routing protocol will be needed as the conventional ad hoc routing protocols such as dynamic source routing (DSR) and ad hoc on-demand distance vector routing (AODV) will not work with such long re-healing times.

155 citations


Proceedings ArticleDOI
09 Sep 2007
TL;DR: It is demonstrated that protocol architectures that exploit multi-packet reception (MPR) do increase the order capacity of random wireless ad hoc networks by a factor Θ(log n) under the protocol model, and it is shown that MPR provides a better capacity improvement for ad hoc Networks than NC when the network experiences a single-source multicast and multi-pair unicasts.
Abstract: The protocols used in ad hoc networks today are based on the assumption that the best way to approach multiple access interference (MAI) is to avoid it. Unfortunately, as the seminal work by Gupta and Kumar has shown, this approach does not scale. Recently, Ahlswede, Ning, Li, and Yeung showed that network coding (NC) can attain the max-flow min-cut throughput for multicast applications in directed graphs with point-to-point links. Motivated by this result, many researchers have attempted to make ad hoc networks scale using NC. However, the work by Liu, Goeckel, and Towsley has shown that NC does not increase the order capacity of wireless ad hoc networks for multi-pair unicast applications. We demonstrate that protocol architectures that exploit multi-packet reception (MPR) do increase the order capacity of random wireless ad hoc networks by a factor Θ(log n) under the protocol model. We also show that MPR provides a better capacity improvement for ad hoc networks than NC when the network experiences a single-source multicast and multi-pair unicasts. Based on these results, we introduce design problems for channel access and routing based on MPR, such that nodes communicate with one another on a many-to-many basis, rather than one-to-one as it is done today, in order to make ad hoc networks truly scalable.

Book
16 Feb 2007
TL;DR: In this article, the authors present an overview of the current state of the art in WSNs and present a policy-based approach for WSN security management, which is based on the one-way property of hash chains.
Abstract: Preface. Foreword. Acknowledgments. 1 Introduction. 1.1 Definition of Wireless Ad Hoc Networks. 1.2 Applications of Wireless Ad Hoc Networks. 1.3 Threats, Attacks, and Vulnerabilities. 1.3.1 Threats. 1.3.2 Vulnerabilities in Ad Hoc Networks. 1.3.3 Attacks. 1.4 Overview of the Book. 2 Basic Security Concepts. 2.1 Introduction. 2.2 Basic Concepts. 2.2.1 Attributes. 2.2.2 Cryptographic Primitives. 2.3 Modes of Operation. 2.4 Miscellaneous Properties. 2.4.1 One-Way Property of Hash Chains. 2.4.2 TESLA. 2.5 Summary. 3 Key Management. 3.1 Introduction. 3.2 Traditional Solution. 3.3 Solutions for Ad Hoc Networks. 3.3.1 Asymmetric Key-Based Approach. 3.3.2 Symmetric Key-Based Approach. 3.4 Summary. 4 Secure Routing. 4.1 Introduction. 4.1.1 Distance-Vector and Link-State Routing. 4.1.2 Proactive vs Reactive Routing. 4.2 Ad Hoc On-Demand Distance Vector. 4.2.1 Secure AODV. 4.2.2 Authenticated Routing for Ad Hoc Networks (ARAN). 4.2.3 Security-Aware Ad Hoc Routing. 4.3 Dynamic Source Routing Protocol. 4.3.1 Secure Routing Protocol. 4.3.2 Ariadne. 4.3.3 EndairA: A Provably Secure Routing Protocol. 4.4 Destination-Sequenced Distance-Vector Routing Protocol. 4.4.1 Secure Efficient Distance Vector Routing (SEAD). 4.4.2 SuperSEAD. 4.4.3 S-DSDV. 4.5 Optimized Link-State Routing Protocol. 4.5.1 Secure Extension to OLSR. 4.5.2 Secure Link-State Routing Protocol. 4.6 Anonymous Routing Protocols. 4.6.1 ANODR. 4.6.2 MASK. 4.7 Generic Attacks Against Routing. 4.7.1 Wormhole Attacks. 4.7.2 Rushing Attacks. 4.7.3 Sybil Attacks. 4.8 Summary. 5 Intrusion Detection Systems. 5.1 Introduction. 5.1.1 Traditional IDS Systems. 5.2 Unique IDS Challenges in MANET. 5.3 Threat Model. 5.4 Architecture for Intrusion Detection in MANET. 5.4.1 Noncollaborative Intrusion Detection System. 5.4.2 Cooperative Intrusion Detection. 5.4.3 Key Novel Concepts for Cooperative Intrusion Detection in MANET. 5.5 Evidence Collection. 5.5.1 Local Evidence. 5.5.2 Promiscuous Monitoring. 5.5.3 Evidence made Available by Other Nodes. 5.6 Detection of Specific Attacks. 5.6.1 Detection of Packet Dropping Attacks. 5.6.2 Detection of Attacks Against Routing Protocols. 5.7 Summary. 6 Policy Management. 6.1 Introduction. 6.2 Policy-Based Network Management. 6.2.1 Overview. 6.2.2 Architecture. 6.2.3 Policy Languages. 6.2.4 Distributed Policy Management Architecture. 6.2.5 IETF and DMTF Standardization Activities. 6.3 Application of Policy Management to Security Management. 6.3.1 Role-Based Access Control (RBAC). 6.3.2 Trust Management and the KeyNote System. 6.3.3 Firewall Management. 6.3.4 Policy Enforcement in a Wireless Ad Hoc Network. 6.4 Summary. 7 Secure Localization. 7.1 Introduction. 7.2 Localization. 7.2.1 Ranging. 7.2.2 Computation. 7.2.3 Attacks. 7.3 Secure Localization. 7.3.1 Distance Bounding Techniques. 7.3.2 Verifiable Multilateration. 7.3.3 Directional Antennae-Based Schemes. 7.3.4 Transmission Range Variation-Based Schemes. 7.3.5 Hybrid Schemes. 7.3.6 Malicious Beacons. 7.4 Summary. 8 Conclusions and Future Research. 8.1 Vehicular Networks. 8.1.1 Differences with MANET. 8.1.2 Open Problems and Solutions. 8.2 Summary. Acronyms. References. Index.

Proceedings ArticleDOI
24 Jun 2007
TL;DR: It is shown that a hierarchical routing scheme based on the MAC association procedures offers several benefits with respect to reactive routing in typical sensor network applications.
Abstract: An IEEE 802.15.4-based wireless sensor network is considered, and the relationship between the IEEE 802.15.4 topology formation mechanism and possible routing strategies at the network layer is studied. Two alternative routing schemes proposed in the framework of the ZigBee alliance are analyzed. The first is the well-known ad-hoc on demand distance vector (AODV) routing protocol, which was designed for highly dynamic application scenarios in wireless ad-hoc networks. The second is a tree-based routing scheme based on a hierarchical structure established among nodes during the network formation phase. This latter approach, referred to as HERA (hierarchical routing algorithm) in the paper, routes packets from sensors to sink based on the parent-child relationships established by the IEEE 802.15.4 topology formation procedure. An extensive simulation analysis is carried out to compare HERA and AODV. It is shown that a hierarchical routing scheme based on the MAC association procedures offers several benefits with respect to reactive routing in typical sensor network applications. Moreover, it is to be noted that most sensor network scenarios are concerned with delivery of packets from a series of static sensors to a single, static, sink.

Proceedings ArticleDOI
01 May 2007
TL;DR: This work proposes a novel protocol named Joint Multi-channel and Multi-path control (JMM) which combines multi-channel link layer with multi-path routing for WMNs and efficiently and intelligently decomposes contending traffics over different channels, different time, and different paths.
Abstract: In recent years, the wireless mesh network (WMN) attracts the interest of many people as a new broadband Internet access technology. However, increasing throughput is still an open and challenging research issue. One potential solution is to enable transceivers to utilize multiple channels dynamically. However, most of existing works do not consider the routing issue, and trivially use some popular single-path routing protocols like AODV and DSR. In this paper, we exploit the benefit of multi-path routing in multi-channel WMNs from the aspect of end-to-end throughput. Between medium access control and network layers, we propose a novel protocol named Joint Multi-channel and Multi-path control (JMM) which combines multi-channel link layer with multi-path routing. Dividing time into slots, JMM coordinates channel usage among slots and schedules traffic flows on dual paths. Our scheme efficiently and intelligently decomposes contending traffics over different channels, different time, and different paths, and hence leads to significant throughput improvement. To the best of our knowledge, this is the first work discussing the joint design of multi-channel control and multi-path routing for WMNs.

01 Jan 2007
TL;DR: This paper examines two on demand routing protocols AODV and DSR based on packet delivery ratio, normalized routing load, normalized MAC load, average end to end delay by varying the number of sources, speed and pause time.
Abstract: Summary Ad hoc networks are characterized by multi-hop wireless connectivity, frequently changing network topology and the need for efficient dynamic routing protocols plays an important role. We compare the performance of two prominent on-demand routing protocols for mobile ad hoc networks: Dynamic Source Routing (DSR), Ad Hoc Ondemand distance Vector Routing (AODV). A detailed simulation model with MAC and physical layer models is used to study the interlayer interactions and their performance implications. We demonstrate that even though DSR and AODV share similar on-demand behavior, the differences in the protocol mechanisms can lead to significant performance differentials. In this paper we examine two on demand routing protocols AODV and DSR based on packet delivery ratio, normalized routing load, normalized MAC load, average end to end delay by varying the number of sources, speed and pause time.

Journal ArticleDOI
01 Mar 2007
TL;DR: This work proposes a multipath on-demand routing protocol (SMORT), which reduces the routing overhead incurred in recovering from route breaks, by using secondary paths, and computes fail-safe multiple paths.
Abstract: Increasing popularity and availability of portable wireless devices, which constitute mobile ad hoc networks, calls for scalable ad hoc routing protocols. On-demand routing protocols adapt well with dynamic topologies of ad hoc networks, because of their lower control overhead and quick response to route breaks. But, as the size of the network increases, these protocols cease to perform due to large routing overhead generated while repairing route breaks. We propose a multipath on-demand routing protocol (SMORT), which reduces the routing overhead incurred in recovering from route breaks, by using secondary paths. SMORT computes fail-safe multiple paths, which provide all the intermediate nodes on the primary path with multiple routes (if exists) to destination. Exhaustive simulations using GloMoSim with large networks (2000 nodes) confirm that SMORT is scalable, and performs better even at higher mobility and traffic loads, when compared to the disjoint multipath routing protocol (DMRP) and ad hoc on-demand distance vector (AODV) routing protocol.

19 Jun 2007
TL;DR: 6LoWPAN Ad Hoc On-Demand Distance Vector Routing (LOAD) is a simplified on- demand routing protocol based on AODV.
Abstract: 6LoWPAN Ad Hoc On-Demand Distance Vector Routing (LOAD) is intended for use by IEEE 802154 devices in a 6LoWPAN It is a simplified on- demand routing protocol based on AODV

Journal ArticleDOI
TL;DR: This paper proposes a location multipath routing-based method by extension of LAR, a performance evaluation and comparison of four routing protocols for ad hoc networks and discusses the solutions for security in a MANET briefly.

Journal ArticleDOI
TL;DR: Two schemes are proposed: AODV-ABR and AODVs-ABL to increase the adaptation of routing protocols to topology changes by modifying A ODV-BR and a performance improvement is evaluated by simulations.

Proceedings ArticleDOI
11 Jun 2007
TL;DR: This paper introduces realistic vehicular mobility traces of downtown Portland, Oregon, obtained fromextremely detailed large scale traffic simulations performed at the Los Alamos National Laboratories (LANL), among the most accurate synthetic motion traces available for study.
Abstract: In an urban environment, vehicles can opportunistically exploit infrastructure through open Access Points (APs) to efficiently communicate with other vehicles. This is to avoid long wireless ad hoc paths, and to alleviate congestion in the wireless grid. Analytic and simulation models are used to optimize the communications and networking strategies. For realistic results, one important challenge is the accurate representation of traffic mobility patterns.In this paper we introduce realistic vehicular mobility traces of downtown Portland, Oregon, obtained fromextremely detailed large scale traffic simulations performed at the Los Alamos National Laboratories (LANL). To the best of our knowledge, these are among the most accurate synthetic motion traces available for study, with the exception of actual car trace measurements. The new mobility model is used to evaluate AODV [1] in flat and opportunistic infrastructure routing. To assess the importance of a realistic mobility model for this evaluation, we compare these results with those obtained with CORSIM [2] traces.The paper makes the following contributions: (a) introduction of efficient, opportunistic strategies for extending the AP infrastructure to use vehicle to vehicle paths, and (b) assessment of different mobility models - CORSIM traces and LANL's realistic vehicular traces - in the modeling of different routing strategies.


Journal ArticleDOI
TL;DR: A stable weight-based on-demand routing protocol (SWORP) for MANETs is proposed and results show that the proposed SWORP outperforms DSR, A ODV, and AODV-RFC, especially in a high mobility environment.

01 Jan 2007
TL;DR: The AntHocNet routing algorithm is presented, which combines ideas from ACO routing with techniques from dynamic programming and other mechanisms taken from more traditional routing algorithms, and can outperform important reference algorithms in the research area.
Abstract: Ad hoc wireless multi-hop networks (AHWMNs) are communication networks that consist entirely of wireless nodes, placed together in an ad hoc manner, i.e. with minimal prior planning. All nodes have routing capabilities, and forward data packets for other nodes in multi-hop fashion. Nodes can enter or leave the network at any time, and may be mobile, so that the network topology continuously experiences alterations during deployment. AHWMNs pose substantially different challenges to networking protocols than more traditional wired networks. These challenges arise from the dynamic and unplanned nature of these networks, from the inherent unreliability of wireless communication, from the limited resources available in terms of bandwidth, processing capacity, etc., and from the possibly large scale of these networks. Due to these different challenges, new algorithms are needed at all layers of the network protocol stack. We investigate the issue of adaptive routing in AHWMNs, using ideas from artificial intelligence (AI). Our main source of inspiration is the field of Ant Colony Optimization (ACO). This is a branch of AI that takes its inspiration from the behavior of ants in nature. ACO has been applied to a wide range of different problems, often giving state-of-the-art results. The application of ACO to the problem of routing in AHWMNs is interesting because ACO algorithms tend to provide properties such as adaptivity and robustness, which are needed to deal with the challenges present in AHWMNs. On the other hand, the field of AHWMNs forms an interesting new application domain in which the ideas of ACO can be tested and improved. In particular, we investigate the combination of ACO mechanisms with other techniques from AI to get a powerful algorithm for the problem at hand. We present the AntHocNet routing algorithm, which combines ideas from ACO routing with techniques from dynamic programming and other mechanisms taken from more traditional routing algorithms. The algorithm has a hybrid architecture, combining both reactive and proactive mechanisms. Through a series of simulation tests, we show that for a wide range of different environments and performance metrics, AntHocNet can outperform important reference algorithms in the research area. We provide an extensive investigation of the internal working of the algorithm, and we also carry out a detailed simulation study in a realistic urban environment. Finally, we discuss the implementation of ACO routing algorithms in a real world testbed.

Proceedings ArticleDOI
12 Aug 2007
TL;DR: A novel cognitive ad hoc routing protocol based on a common link control radio (CLCR) called a minimum weight routing protocol is proposed that can greatly reduce communication overhead in cognitive wireless ad hoc networks.
Abstract: Cognitive wireless ad hoc is highly focused as a promising future wireless technology. However, cognitive wireless ad hoc networks have some difficulties of neighbor discovery and routing. For helping neighbor discovery and routing in the cognitive wireless ad hoc networks, we introduce a common link control radio (CLCR) that is a common active wireless system of cognitive terminals. In addition, we propose a novel cognitive ad hoc routing protocol based on a common link control radio (CLCR) called a minimum weight routing protocol. We show that the proposed routing protocol can greatly reduce communication overhead in cognitive wireless ad hoc networks.

Proceedings ArticleDOI
15 Oct 2007
TL;DR: In this article, the authors proposed two probabilistic methods for on-demand route discovery, which can significantly reduce the overhead involved in the dissemination of RREQs in AODV.
Abstract: Conventional on-demand route discovery methods in mobile ad hoc networks (MANET) employ blind flooding, where a mobile node blindly rebroadcasts received Route Request (RREQ) packets until a route to a particular destination is established This can potentially lead to high channel contention, causing redundant retransmissions and thus excessive packet collisions in the network Such a phenomenon induces what is known as broadcast storm problem, which has been shown to greatly increase the network communication overhead and end-to-end delay In this paper, we show that the deleterious impact of such a problem can be reduced if measures are taken during the dissemination of RREQ packets We propose two new probabilistic methods for on-demand route discovery, that is simple to implement and can significantly reduce the overhead involved in the dissemination of RREQs Our analysis reveals that equipping AODV with probabilistic route discovery can result in significant performance improvements on all the standard metrics

Proceedings ArticleDOI
01 Jan 2007
TL;DR: A transmission time based mechanism (TTM) to detect wormhole attacks - one of the most popular & serious attacks in Wireless Ad Hoc Networks.
Abstract: Important applications of Wireless Ad Hoc Networks make them very attractive to attackers, therefore more research is required to guarantee the security for Wireless Ad Hoc Networks. In this paper, we proposed a transmission time based mechanism (TTM) to detect wormhole attacks - one of the most popular & serious attacks in Wireless Ad Hoc Networks. TTM detects wormhole attacks during route setup procedure by computing transmission time between every two successive nodes along the established path. Wormhole is identified base on the fact that transmission time between two fake neighbors created by wormhole is considerably higher than that between two real neighbors which are within radio range of each other. TTM has good performance, little overhead and no special hardware required. TTM is designed specifically for Ad Hoc On-Demand Vector Routing Protocol (AODV) but it can be extended to work with other routing protocols.

01 Jan 2007
TL;DR: This paper gives a brief introduction to the TrueTime simulator and then gives several examples on how TrueTime can be used to simulate networked control systems.
Abstract: This paper gives a brief introduction to the TrueTime simulator and then gives several examples on how TrueTime can be used to simulate networked control systems. Among the examples are time-triggered and event-based networked control and AODV routing in wireless ad-hoc networks.

01 Jan 2007
TL;DR: Experimental results illustrate that performance of the routing protocol varies across different parameters like number of nodes, packet delivery ratio and end to end delay.
Abstract: Summary A mobile ad hoc network (MANET) is a network consisting of a set of wireless mobile nodes that communicate with each other without centralized control or established infrastructure. The mobility model represents the moving behavior of each mobile node (MN) in the MANET that should be realistic. It is a crucial part in the performance evaluation of MANET. In this paper, we have studied the effects of various random mobility models on the performance of AODV. For experimental purposes, we have considered three mobility scenarios: Random Waypoint, Random Walk with Reflections and Random Walk with Wrapping. Experimental results illustrate that performance of the routing protocol varies across different parameters like number of nodes, packet delivery ratio and end to end delay.

Journal ArticleDOI
TL;DR: This paper proposes a hierarchical key management scheme (HKMS) for secure group communications in MANETs and conducts the security and performance analysis to compare the proposed scheme with Tseng et al.'s (2007) scheme.

Proceedings ArticleDOI
15 Oct 2007
TL;DR: The proposed method for improving quality of ad-hoc multihop wireless communications between moving vehicles is implemented as middleware supporting real-time packet transmissions such as VoIP, and measurement results showing maximum packet loss lower than 5 % are obtained.
Abstract: We demonstrate a method for improving quality of ad-hoc multihop wireless communications between moving vehicles. This method is designed to overcome problems of high packet loss and route instability common in inter-vehicular communications. We implemented the proposed method as middleware supporting real-time packet transmissions such as VoIP, and evaluated the performance in experimental tests, including a 3-vehicle test on a public road. We obtained measurement results showing maximum packet loss lower than 5 %, compared to more than 80% with existing implementations of the ad hoc routing protocols OLSR and AODV. We also showed that it is possible to support good quality VoIP broadcasts at normal traffic speeds of from 40km/h to 60 km/h on open roads.