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Showing papers on "Wireless Routing Protocol published in 2003"


01 Jul 2003
TL;DR: A logging instrument contains a pulsed neutron source and a pair of radiation detectors spaced along the length of the instrument to provide an indication of formation porosity which is substantially independent of the formation salinity.
Abstract: The Ad hoc On-Demand Distance Vector (AODV) routing protocol is intended for use by mobile nodes in an ad hoc network. It offers quick adaptation to dynamic link conditions, low processing and memory overhead, low network utilization, and determines unicast routes to destinations within the ad hoc network. It uses destination sequence numbers to ensure loop freedom at all times (even in the face of anomalous delivery of routing control messages), avoiding problems (such as "counting to infinity") associated with classical distance vector protocols.

11,490 citations


01 Oct 2003
TL;DR: The Optimized Link State Routing protocol is an optimization of the classical link state algorithm tailored to the requirements of a mobile wireless LAN and provides optimal routes (in terms of number of hops).
Abstract: This document describes the Optimized Link State Routing (OLSR) protocol for mobile ad hoc networks. The protocol is an optimization of the classical link state algorithm tailored to the requirements of a mobile wireless LAN. The key concept used in the protocol is that of multipoint relays (MPRs). MPRs are selected nodes which forward broadcast messages during the flooding process. This technique substantially reduces the message overhead as compared to a classical flooding mechanism, where every node retransmits each message when it receives the first copy of the message. In OLSR, link state information is generated only by nodes elected as MPRs. Thus, a second optimization is achieved by minimizing the number of control messages flooded in the network. As a third optimization, an MPR node may chose to report only links between itself and its MPR selectors. Hence, as contrary to the classic link state algorithm, partial link state information is distributed in the network. This information is then used for route calculation. OLSR provides optimal routes (in terms of number of hops). The protocol is particularly suitable for large and dense networks as the technique of MPRs works well in this context.

5,442 citations


Journal ArticleDOI
11 May 2003
TL;DR: This work proposes security goals for routing in sensor networks, shows how attacks against ad-hoc and peer-to-peer networks can be adapted into powerful attacks against sensors, and introduces two classes of novel attacks against sensor networks sinkholes and HELLO floods.
Abstract: We consider routing security in wireless sensor networks. Many sensor network routing protocols have been proposed, but none of them have been designed with security as a goal. We propose security goals for routing in sensor networks, show how attacks against ad-hoc and peer-to-peer networks can be adapted into powerful attacks against sensor networks, introduce two classes of novel attacks against sensor networks sinkholes and HELLO floods, and analyze the security of all the major sensor network routing protocols. We describe crippling attacks against all of them and suggest countermeasures and design considerations. This is the first such analysis of secure routing in sensor networks.

2,946 citations


Journal ArticleDOI
TL;DR: A probabilistic routing protocol for intermittently connected networks where there is no guarantee that a fully connected path between source and destination exist at any time, rendering traditional routing protocols unable to deliver messages between hosts.
Abstract: We consider the problem of routing in intermittently connected networks. In such networks there is no guarantee that a fully connected path between source and destination exist at any time, rendering traditional routing protocols unable to deliver messages between hosts. We propose a probabilistic routing protocol for such networks.

2,530 citations


Proceedings ArticleDOI
05 Nov 2003
TL;DR: This work study and evaluate link estimator, neighborhood table management, and reliable routing protocol techniques, and narrow the design space through evaluations on large-scale, high-level simulations to 50-node, in-depth empirical experiments.
Abstract: The dynamic and lossy nature of wireless communication poses major challenges to reliable, self-organizing multihop networks. These non-ideal characteristics are more problematic with the primitive, low-power radio transceivers found in sensor networks, and raise new issues that routing protocols must address. Link connectivity statistics should be captured dynamically through an efficient yet adaptive link estimator and routing decisions should exploit such connectivity statistics to achieve reliability. Link status and routing information must be maintained in a neighborhood table with constant space regardless of cell density. We study and evaluate link estimator, neighborhood table management, and reliable routing protocol techniques. We focus on a many-to-one, periodic data collection workload. We narrow the design space through evaluations on large-scale, high-level simulations to 50-node, in-depth empirical experiments. The most effective solution uses a simple time averaged EWMA estimator, frequency based table management, and cost-based routing.

1,735 citations


Journal ArticleDOI
TL;DR: This work is proposing APS – a localized, distributed, hop by hop positioning algorithm, that works as an extension of both distance vector routing and GPS positioning in order to provide approximate position for all nodes in a network where only a limited fraction of nodes have self positioning capability.
Abstract: Many ad hoc network protocols and applications assume the knowledge of geographic location of nodes. The absolute position of each networked node is an assumed fact by most sensor networks which can then present the sensed information on a geographical map. Finding position without the aid of GPS in each node of an ad hoc network is important in cases where GPS is either not accessible, or not practical to use due to power, form factor or line of sight conditions. Position would also enable routing in sufficiently isotropic large networks, without the use of large routing tables. We are proposing APS --- a localized, distributed, hop by hop positioning algorithm, that works as an extension of both distance vector routing and GPS positioning in order to provide approximate position for all nodes in a network where only a limited fraction of nodes have self positioning capability.

1,700 citations


Proceedings ArticleDOI
09 Jul 2003
TL;DR: A new, general mechanism, called packet leashes, is presented for detecting and thus defending against wormhole attacks, and a specific protocol is presented, called TIK, that implements leashes.
Abstract: As mobile ad hoc network applications are deployed, security emerges as a central requirement. In this paper, we introduce the wormhole attack, a severe attack in ad hoc networks that is particularly challenging to defend against. The wormhole attack is possible even if the attacker has not compromised any hosts, and even if all communication provides authenticity and confidentiality. In the wormhole attack, an attacker records packets (or bits) at one location in the network, tunnels them (possibly selectively) to another location, and retransmits them there into the network. The wormhole attack can form a serious threat in wireless networks, especially against many ad hoc network routing protocols and location-based wireless security systems. For example, most existing ad hoc network routing protocols, without some mechanism to defend against the wormhole attack, would be unable to find routes longer than one or two hops, severely disrupting communication. We present a new, general mechanism, called packet leashes, for detecting and thus defending against wormhole attacks, and we present a specific protocol, called TIK, that implements leashes.

1,667 citations


Journal ArticleDOI
01 Jul 2003
TL;DR: The important role that mobile ad hoc networks play in the evolution of future wireless technologies is explained and the latest research activities in these areas are reviewed, including a summary of MANETs characteristics, capabilities, applications, and design constraints.
Abstract: Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, ‘‘ad-hoc’’ network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, e.g., disaster recovery environments. Ad hoc networking concept is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad hoc paradigm. Recently, the introduction of new technologies such as the Bluetooth, IEEE 802.11 and Hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent evolutions have been generating a renewed and growing interest in the research and development of MANET. This paper attempts to provide a comprehensive overview of this dynamic field. It first explains the important role that mobile ad hoc networks play in the evolution of future wireless technologies. Then, it reviews the latest research activities in these areas, including a summary of MANETs characteristics, capabilities, applications, and design constraints. The paper concludes by presenting a set of challenges and problems requiring further research in the future. � 2003 Elsevier B.V. All rights reserved.

1,430 citations


Proceedings ArticleDOI
09 Jul 2003
TL;DR: This study examines the random waypoint model widely used in the simulation studies of mobile ad hoc networks and shows that this model fails to provide a steady state in that the average nodal speed consistently decreases over time, and should not be directly used for simulation.
Abstract: This study examines the random waypoint model widely used in the simulation studies of mobile ad hoc networks. Our findings show that this model fails to provide a steady state in that the average nodal speed consistently decreases over time, and therefore should not be directly used for simulation. We show how unreliable results can be obtained by using this model. In particular, certain ad hoc routing metrics can drop by as much as 40% over the course of a 900-second simulation using the random waypoint model. We give both an intuitive and a formal explanation for this phenomenon. We also propose a simple fix of the problem and discuss a few alternatives. Our modified random waypoint model is able to reach a steady state and simulation results are presented.

1,268 citations


Proceedings ArticleDOI
09 Jul 2003
TL;DR: This framework aims to evaluate the impact of different mobility models on the performance of MANET routing protocols, and attempts to decompose the routing protocols into mechanistic "building blocks" to gain a deeper insight into the performance variations across protocols in the face of mobility.
Abstract: A mobile ad hoc network (MANET) is a collection of wireless mobile nodes forming a temporary network without using any existing infrastructure. Since not many MANETs are currently deployed, research in this area is mostly simulation based. Random waypoint is the commonly used mobility model in these simulations. Random waypoint is a simple model that may be applicable to some scenarios. However, we believe that it is not sufficient to capture some important mobility characteristics of scenarios in which MANETs may be deployed. Our framework aims to evaluate the impact of different mobility models on the performance of MANET routing protocols. We propose various protocol independent metrics to capture interesting mobility characteristics, including spatial and temporal dependence and geographic restrictions. In addition, a rich set of parameterized mobility models is introduced including random waypoint, group mobility, freeway and Manhattan models. Based on these models several 'test-suite' scenarios are chosen carefully to span the metric space. We demonstrate the utility of our test-suite by evaluating various MANET routing protocols, including DSR, AODV and DSDV. Our results show that the protocol performance may vary drastically across mobility models and performance rankings of protocols may vary with the mobility models used. This effect can be explained by the interaction of the mobility characteristics with the connectivity graph properties. Finally, we attempt to decompose the routing protocols into mechanistic "building blocks" to gain a deeper insight into the performance variations across protocols in the face of mobility.

1,035 citations


Proceedings ArticleDOI
09 Jun 2003
TL;DR: This paper analyzes a position-based routing approach that makes use of the navigational systems of vehicles and compares this approach with non-position-based ad hoc routing strategies (dynamic source routing and ad-hoc on-demand distance vector routing).
Abstract: Routing of data in a vehicular ad hoc network is a challenging task due to the high dynamics of such a network. Recently, it was shown for the case of highway traffic that position-based routing approaches can very well deal with the high mobility of network nodes. However, baseline position-based routing has difficulties to handle two-dimensional scenarios with obstacles (buildings) and voids as it is the case for city scenarios. In this paper we analyze a position-based routing approach that makes use of the navigational systems of vehicles. By means of simulation we compare this approach with non-position-based ad hoc routing strategies (dynamic source routing and ad-hoc on-demand distance vector routing). The simulation makes use of highly realistic vehicle movement patterns derived from Daimler-Chrysler's Videlio traffic simulator. While DSR's performance is limited due to problems with scalability and handling mobility, both AODV and the position-based approach show good performances with the position-based approach outperforming AODV.

Proceedings ArticleDOI
14 Sep 2003
TL;DR: This paper defines a scalable coordinate-based routing algorithm that does not rely on location information, and thus can be used in a wide variety of ad hoc and sensornet environments.
Abstract: For many years, scalable routing for wireless communication systems was a compelling but elusive goal. Recently, several routing algorithms that exploit geographic information (e.g. GPSR) have been proposed to achieve this goal. These algorithms refer to nodes by their location, not address, and use those coordinates to route greedily, when possible, towards the destination. However, there are many situations where location information is not available at the nodes, and so geographic methods cannot be used. In this paper we define a scalable coordinate-based routing algorithm that does not rely on location information, and thus can be used in a wide variety of ad hoc and sensornet environments.

Journal ArticleDOI
01 Jul 2003
TL;DR: The Secure Efficient Ad hoc Distance vector routing protocol (SEAD) is designed and evaluated, a secure ad hoc network routing protocol based on the design of the Destination-Sequenced Distance-Vector routing protocol that performs well over the range of scenarios and is robust against multiple uncoordinated attackers creating incorrect routing state in any other node.
Abstract: An ad hoc network is a collection of wireless computers (nodes), communicating among themselves over possibly multihop paths, without the help of any infrastructure such as base stations or access points. Although many previous ad hoc network routing protocols have been based in part on distance vector approaches, they have generally assumed a trusted environment. In this paper, we design and evaluate the Secure Efficient Ad hoc Distance vector routing protocol (SEAD), a secure ad hoc network routing protocol based on the design of the Destination-Sequenced Distance-Vector routing protocol. In order to support use with nodes of limited CPU processing capability, and to guard against Denial-of-Service attacks in which an attacker attempts to cause other nodes to consume excess network bandwidth or processing time, we use efficient one-way hash functions and do not use asymmetric cryptographic operations in the protocol. SEAD performs well over the range of scenarios we tested, and is robust against multiple uncoordinated attackers creating incorrect routing state in any other node, even in spite of any active attackers or compromised nodes in the network.

Proceedings ArticleDOI
13 Jul 2003
TL;DR: A new geometric routing algorithm is proposed which is outstandingly efficient on practical average-case networks, however is also in theory asymptotically worst-case optimal and the formerly necessary assumption that the distance between network nodes may not fall below a constant value is dropped.
Abstract: All too often a seemingly insurmountable divide between theory and practice can be witnessed. In this paper we try to contribute to narrowing this gap in the field of ad-hoc routing. In particular we consider two aspects: We propose a new geometric routing algorithm which is outstandingly efficient on practical average-case networks, however is also in theory asymptotically worst-case optimal. On the other hand we are able to drop the formerly necessary assumption that the distance between network nodes may not fall below a constant value, an assumption that cannot be maintained for practical networks. Abandoning this assumption we identify from a theoretical point of view two fundamentamentally different classes of cost metrics for routing in ad-hoc networks.


Proceedings ArticleDOI
19 Sep 2003
TL;DR: The rushing attack is presented, a new attack that results in denial-of-service when used against all previous on-demand ad~hoc network routing protocols, and Rushing Attack Prevention (RAP) is developed, a generic defense against the rushing attack for on- demand protocols.
Abstract: In an ad hoc network, mobile computers (or nodes) cooperate to forward packets for each other, allowing nodes to communicate beyond their direct wireless transmission range. Many of the proposed routing protocols for ad hoc networks operate in an on-demand fashion, as on-demand routing protocols have been shown to often have lower overhead and faster reaction time than other types of routing based on periodic (proactive) mechanisms. Significant attention recently has been devoted to developing secure routing protocols for ad~hoc networks, including a number of secure on-demand routing protocols, that defend against a variety of possible attacks on network routing. In this paper, we present the rushing attack, a new attack that results in denial-of-service when used against all previous on-demand ad~hoc network routing protocols. For example, DSR, AODV, and secure protocols based on them, such as Ariadne, ARAN, and SAODV, are unable to discover routes longer than two hops when subject to this attack. This attack is also particularly damaging because it can be performed by a relatively weak attacker. We analyze why previous protocols fail under this attack. We then develop Rushing Attack Prevention (RAP), a generic defense against the rushing attack for on-demand protocols. RAP incurs no cost unless the underlying protocol fails to find a working route, and it provides provable security properties even against the strongest rushing attackers.

Journal ArticleDOI
TL;DR: Numerical results indicate thatMultihop routing, the ability for concurrent transmissions, and SIC significantly increase the capacity of ad hoc and multihop cellular networks and energy-constraint networks.
Abstract: We define and study capacity regions for wireless ad hoc networks with an arbitrary number of nodes and topology. These regions describe the set of achievable rate combinations between all source-destination pairs in the network under various transmission strategies, such as variable-rate transmission, single-hop or multihop routing, power control, and successive interference cancellation (SIC). Multihop cellular networks and networks with energy constraints are studied as special cases. With slight modifications, the developed formulation can handle node mobility and time-varying flat-fading channels. Numerical results indicate that multihop routing, the ability for concurrent transmissions, and SIC significantly increase the capacity of ad hoc and multihop cellular networks. On the other hand, gains from power control are significant only when variable-rate transmission is not used. Also, time-varying flat-fading and node mobility actually improve the capacity. Finally, multihop routing greatly improves the performance of energy-constraint networks.

Proceedings ArticleDOI
09 Jul 2003
TL;DR: This work considers two different routing strategies and study the scaling behavior of the throughput capacity of a hybrid network, finding that if m grows asymptotically slower than √n, the benefit of adding base stations on capacity is insignificant, however, ifm grows faster than ∞, the throughputcapacity increases linearly with the number of base stations, providing an effective improvement over a pure ad hoc network.
Abstract: This paper involves the study of the throughput capacity of hybrid wireless networks. A hybrid network is formed by placing a sparse network of base stations in an ad hoc network. These base stations are assumed to be connected by a high-bandwidth wired network and act as relays for wireless nodes. They are not data sources nor data receivers. Hybrid networks present a tradeoff between traditional cellular networks and pure ad hoc networks in that data may be forwarded in a multihop fashion or through the infrastructure. It has been shown that the capacity of a random ad hoc network does not scale well with the number of nodes in the system. In this work, we consider two different routing strategies and study the scaling behavior of the throughput capacity of a hybrid network. Analytical expressions of the throughput capacity are obtained. For a hybrid network of n nodes and m base stations, the results show that if m grows asymptotically slower than √n, the benefit of adding base stations on capacity is insignificant. However, if m grows faster than √n, the throughput capacity increases linearly with the number of base stations, providing an effective improvement over a pure ad hoc network. Therefore, in order to achieve nonnegligible capacity gain, the investment in the wired infrastructure should be high enough.

Journal ArticleDOI
01 Feb 2003
TL;DR: This work introduces a resource reservation-based routing and signaling algorithm, Ad hoc Qos on-demand routing (AQOR), that provides end-to-end quality of service (QoS) support in mobile ad hoc networks (MANETs).
Abstract: We introduce a resource reservation-based routing and signaling algorithm, Ad hoc Qos on-demand routing (AQOR), that provides end-to-end quality of service (QoS) support, in terms of bandwidth and end-to-end delay, in mobile ad hoc networks (MANETs). The increasing use of MANETs for transferring multimedia applications such as voice, video and data, leads to the need to provide QoS support. To perform accurate admission control and resource reservation in AQOR, we have developed detailed computations that allow us to estimate the available bandwidth and end-to-end delay in unsynchronized wireless environment. AQOR also includes efficient mechanisms for QoS maintenance, including temporary reservation and destination-initiated recovery processes. The performance of AQOR is studied in detail by simulation using OPNET Modeler. The results validate that AQOR provides QoS support in ad hoc wireless networks with high reliability and low overhead.

Proceedings ArticleDOI
09 Jul 2003
TL;DR: A modified version of the popular AODV protocol that allows us to discover multiple node-disjoint paths from a source to a destination and shows that the probability of establishing a reliable path between a random source and destination pair increases considerably even with a low percentage of reliable nodes.
Abstract: Mobile ad hoc networks consist of nodes that are often vulnerable to failure. As such, it is important to provide redundancy in terms of providing multiple node-disjoint paths from a source to a destination. We first propose a modified version of the popular AODV protocol that allows us to discover multiple node-disjoint paths from a source to a destination. We find that very few of such paths can be found. Furthermore, as distances between sources and destinations increase, bottlenecks inevitably occur and thus, the possibility of finding multiple paths is considerably reduced. We conclude that it is necessary to place what we call reliable nodes (in terms of both being robust to failure and being secure) in the network for efficient operations. We propose a deployment strategy that determines the positions and the trajectories of these reliable nodes such that we can achieve a framework for reliably routing information. We define a notion of a reliable path which is made up of multiple segments, each of which either entirely consists of reliable nodes, or contains a preset number of multiple paths between the end points of the segment. We show that the probability of establishing a reliable path between a random source and destination pair increases considerably even with a low percentage of reliable nodes when we control their positions and trajectories in accordance with our algorithm.

Journal ArticleDOI
01 Nov 2003
TL;DR: This framework aims to evaluate the impact of different mobility models on the performance of MANET routing protocols, and attempts to decompose the reactive routing protocols into mechanistic ‘‘building blocks’’ to gain a deeper insight into the performance variations across protocols in the face of mobility.
Abstract: A Mobile Ad hoc Network (MANET) is a collection of wireless mobile nodes forming a temporary network without using any existing infrastructure. Since not many MANETs are currently deployed, research in this area is mostly simulation based. Random Waypoint is the commonly used mobility model in these simulations. Random Waypoint is a simple model that may be applicable to some scenarios. However, we believe that it is not sufficient to capture some important mobility characteristics of scenarios in which MANETs may be deployed. Our framework aims to evaluate the impact of different mobility models on the performance of MANET routing protocols. We propose various protocol independent metrics to capture interesting mobility characteristics, including spatial and temporal dependence and geographic restrictions. In addition, a rich set of parameterized mobility models is introduced including Random Waypoint, Group Mobility, Freeway and Manhattan models. Based on these models several test-suite scenarios are chosen carefully to span the metric space. We demonstrate the utility of our test-suite by evaluating various MANET routing protocols, including DSR, AODV and DSDV. Our results show that the protocol performance may vary drastically across mobility models and performance rankings of protocols may vary with the mobility models used. This effect can be explained by the interaction of the mobility characteristics with the connectivity graph properties. Finally, we attempt to decompose the reactive routing protocols into mechanistic ‘‘building blocks’’ to gain a deeper insight into the performance variations across protocols in the face of mobility. � 2003 Elsevier B.V. All rights reserved.

Proceedings ArticleDOI
01 Jun 2003
TL;DR: GOAFR is the first ad-hoc algorithm to be both asymptotically optimal and average-case efficient and study a dozen of routing algorithms and shows that GOAFR outperforms other prominent algorithms, such as GPSR or AFR.
Abstract: In this paper we present GOAFR, a new geometric ad-hoc routing algorithm combining greedy and face routing. We evaluate this algorithm by both rigorous analysis and comprehensive simulation. GOAFR is the first ad-hoc algorithm to be both asymptotically optimal and average-case efficient. For our simulations we identify a network density range critical for any routing algorithm. We study a dozen of routing algorithms and show that GOAFR outperforms other prominent algorithms, such as GPSR or AFR.

Proceedings ArticleDOI
19 May 2003
TL;DR: This paper proposes an energy-aware QoS routing protocol, which finds a least-cost, delay-constrained path for real-time data in terms of link cost that captures nodes' energy reserve, transmission energy, error rate and other communication parameters.
Abstract: Recent advances in wireless sensor networks have led to many new routing protocols specifically designed for sensor networks. Almost all of these routing protocols considered energy efficiency as the ultimate objective in order to maximize the whole network lifetime. However, the introduction of video and imaging sensors has posed additional challenges. Transmission of video and imaging data requires both energy and QoS aware routing in order to ensure efficient usage of the sensors and effective access to the gathered measurements. In this paper, we propose an energy-aware QoS routing protocol, which can also run efficiently with best-effort traffic. The protocol finds a least-cost, delay-constrained path for real-time data in terms of link cost that captures nodes' energy reserve, transmission energy, error rate and other communication parameters. Moreover, throughput for non-real-time data is maximized by adjusting the service rate for both real-time and non-realtime data at sensor nodes. Simulation results have demonstrated the effectiveness of our approach.

Proceedings ArticleDOI
14 Sep 2003
TL;DR: Ad hoc-VCG is proposed, a reactive routing protocol that achieves the design objectives of truthfulness and cost-efficiency and guarantees that routing is done along the most cost-efficient path by paying to the intermediate nodes a premium over their actual costs for forwarding data packets.
Abstract: We introduce a game-theoretic setting for routing in a mobile ad hoc network that consists of greedy, selfish agents who accept payments for forwarding data for other agents if the payments cover their individual costs incurred by forwarding data. In this setting, we propose Ad hoc-VCG, a reactive routing protocol that achieves the design objectives of truthfulness (i.e., it is in the agents' best interest to reveal their true costs for forwarding data) and cost-efficiency (i.e., it guarantees that routing is done along the most cost-efficient path) in a game-theoretic sense by paying to the intermediate nodes a premium over their actual costs for forwarding data packets. We show that the total overpayment (i.e., the sum of all premiums paid) is relatively small by giving a theoretical upper bound and by providing experimental evidence. Our routing protocol implements a variation of the well-known mechanism by Vickrey, Clarke, and Groves in a mobile network setting. Finally, we analyze a very natural routing protocol that is an adaptation of the Packet Purse Model [8] with auctions in our setting and show that, unfortunately, it does not achieve cost-efficiency or truthfulness.

Book ChapterDOI
12 Oct 2003
TL;DR: The issues of multipath routing in MANETs are examined to support application constraints such as reliability, load-balancing, energy-conservation, and Quality-of-Service (QoS).
Abstract: Mobile ad hoc networks (MANETs) consist of a collection of wireless mobile nodes which dynamically exchange data among themselves without the reliance on a fixed base station or a wired backbone network MANET nodes are typically distinguished by their limited power, processing, and memory resources as well as high degree of mobility In such networks, the wireless mobile nodes may dynamically enter the network as well as leave the network Due to the limited transmission range of wireless network nodes, multiple hops are usually needed for a node to exchange information with any other node in the network Thus routing is a crucial issue to the design of a MANET In this paper, we specifically examine the issues of multipath routing in MANETs Multipath routing allows the establishment of multiple paths between a single source and single destination node It is typically proposed in order to increase the reliability of data transmission (ie, fault tolerance) or to provide load balancing Load balancing is of especial importance in MANETs because of the limited bandwidth between the nodes We also discuss the application of multipath routing to support application constraints such as reliability, load-balancing, energy-conservation, and Quality-of-Service (QoS)

Proceedings ArticleDOI
01 Jun 2003
TL;DR: ANODR, an anonymous on-demand routing protocol for mobile ad hoc networks deployed in hostile environments, addresses two closely related problems: for route anonymity, ANODR prevents strong adversaries from tracing a packet flow back to its source or destination; for location privacy, AN ODR ensures that adversaries cannot discover the real identities of local transmitters.
Abstract: In hostile environments, the enemy can launch traffic analysis against interceptable routing information embedded in routing messages and data packets. Allowing adversaries to trace network routes and infer the motion pattern of nodes at the end of those routes may pose a serious threat to covert operations. We propose ANODR, an anonymous on-demand routing protocol for mobile ad hoc networks deployed in hostile environments. We address two closely related problems: For route anonymity, ANODR prevents strong adversaries from tracing a packet flow back to its source or destination; for location privacy, ANODR ensures that adversaries cannot discover the real identities of local transmitters. The design of ANODR is based on "broadcast with trapdoor information", a novel network security concept which includes features of two existing network and security mechanisms, namely "broadcast" and "trapdoor information". We use simulations and implementation to validate the effectiveness of our design.

Proceedings ArticleDOI
27 Jan 2003
TL;DR: The proposed secure link state routing protocol (SLSP) provides secure proactive topology discovery, which can be beneficial to network operation in a number of ways.
Abstract: Secure operation of the routing protocol is one of the major challenges to be met for the proliferation of the mobile ad hoc networking (MANET) paradigm. Nevertheless, security enhancements have been proposed mostly for reactive MANET protocols. The proposed secure link state routing protocol (SLSP) provides secure proactive topology discovery, which can be beneficial to network operation in a number of ways. SLSP can be employed as a stand-alone protocol, or fit naturally into a hybrid routing framework, when combined with a reactive protocol. SLSP is robust against individual attackers, is capable of adjusting its scope between local and network-wide topology discovery, and is capable of operating in networks of frequently changing topology and membership.

Journal ArticleDOI
01 Jan 2003
TL;DR: Experimental evidence from two wireless test-beds shows that there are usually multiple minimum hop-count paths, many of which have poor throughput, and suggests that more attention be paid to link quality when choosing ad hoc routes.
Abstract: Existing wireless ad hoc routing protocols typically find routes with the minimum hop-count. This paper presents experimental evidence from two wireless test-beds which shows that there are usually multiple minimum hop-count paths, many of which have poor throughput. As a result, minimum-hop-count routing often chooses routes that have significantly less capacity than the best paths that exist in the network. Much of the reason for this is that many of the radio links between nodes have loss rates low enough that the routing protocol is willing to use them, but high enough that much of the capacity is consumed by retransmissions. These observations suggest that more attention be paid to link quality when choosing ad hoc routes; the paper presents measured link characteristics likely to be useful in devising a better path quality metric.

Proceedings ArticleDOI
01 Jun 2003
TL;DR: A new MAC protocol is proposed that deals effectively with the hidden terminal problem, the problem of deafness and theproblem of determination of neighbors' location and offers significant improvement compared to the performance of omni transmissions.
Abstract: Directional antennas in ad hoc networks offer many benefits compared with classical omnidirectional antennas. The most important include significant increase of spatial reuse, coverage range and subsequently network capacity as a whole. On the other hand, the use of directional antennas requires new approach in the design of a MAC protocol to fully exploit these benefits. Unfortunately, directional transmissions increase the hidden terminal problem, the problem of deafness and the problem of determination of neighbors' location. In this paper we propose a new MAC protocol that deals effectively with these problems while it exploits in an efficient way the advantages of the directional antennas. We evaluate our work through simulation study. Numerical results show that our protocol offers significant improvement compared to the performance of omni transmissions.

01 Jan 2003
TL;DR: In this paper, it is shown that in order to find the routes that give energy efficiency, a set of partial differential equations similar to the Maxwell's equations in the electrostatic theory can be solved.
Abstract: In this paper we introduce a new scheme for the purpose of routing in the wireless sensor networks. Our proposed approach is for the case in which many sensors need to collect data and send it to a central node. We will show that in order to find the routes that give energy efficiency, we can solve a set of partial differential equations similar to the Maxwell’s equations in the electrostatic theory. These partial differential equations give the geographical paths from each sensor to the destination. In order to find the actual routes, we approximate the found paths by a sequence of wireless links each between a pair of sensors. Our simulation results show considerable improvement in the life of the network compared to the traditional shortest path approach.