Ad hoc On-Demand Distance Vector (AODV) Routing
01 Jul 2003-Vol. 3561, pp 1-37
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.
Citations
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01 Jan 2002
TL;DR: The ASCENT algorithm is motivated and described and it is shown that the system achieves linear increase in energy savings as a function of the density and the convergence time required in case of node failures while still providing adequate connectivity.
Abstract: Advances in microsensor and radio technology enable small but smart sensors to be deployed for a wide range of environmental monitoring applications. The low-per node cost allows these wireless networks of sensors and actuators to be densely distributed. The nodes in these dense networks coordinate to perform the distributed sensing and actuation tasks. Moreover, as described in this paper, the nodes can also coordinate to exploit the redundancy provided by high density so as to extend overall system lifetime. The large number of nodes deployed in this systems preclude manual configuration, and the environmental dynamics precludes design-time preconfiguration. Therefore, nodes have to self-configure to establish a topology that provides communication under stringent energy constraints. ASCENT builds on the notion that, as density increases, only a subset of the nodes is necessary to establish a routing forwarding backbone. In ASCENT, each node assesses its connectivity and adapts its participation in the multihop network topology based on the measured operating region. This paper motivates and describes the ASCENT algorithm and presents analysis, simulation, and experimental measurements. We show that the system achieves linear increase in energy savings as a function of the density and the convergence time required in case of node failures while still providing adequate connectivity.
851Â citations
TL;DR: A model of wireless networks that particularly takes into account the distances between nodes, and the resulting attenuation of radio signals, is formulated, and a performance measure that weights information by the distance over which it is transported is studied.
Abstract: How much information can be carried over a wireless network with a multiplicity of nodes, and how should the nodes cooperate to transfer information? To study these questions, we formulate a model of wireless networks that particularly takes into account the distances between nodes, and the resulting attenuation of radio signals, and study a performance measure that weights information by the distance over which it is transported. Consider a network with the following features. I) n nodes located on a plane, with minimum separation distance /spl rho//sub min/>0. II) A simplistic model of signal attenuation e/sup -/spl gamma//spl rho////spl rho//sup /spl delta// over a distance /spl rho/, where /spl gamma//spl ges/0 is the absorption constant (usually positive, unless over a vacuum), and /spl delta/>0 is the path loss exponent. III) All receptions subject to additive Gaussian noise of variance /spl sigma//sup 2/. The performance measure we mainly, but not exclusively, study is the transport capacity C/sub T/:=sup/spl Sigma/on/sub /spl lscr/=1//sup m/R/sub /spl lscr///spl middot//spl rho//sub /spl lscr//, where the supremum is taken over m, and vectors (R/sub 1/,R/sub 2/,...,R/sub m/) of feasible rates for m source-destination pairs, and /spl rho//sub /spl lscr// is the distance between the /spl lscr/th source and its destination. It is the supremum distance-weighted sum of rates that the wireless network can deliver. We show that there is a dichotomy between the cases of relatively high and relatively low attenuation. When /spl gamma/>0 or /spl delta/>3, the relatively high attenuation case, the transport capacity is bounded by a constant multiple of the sum of the transmit powers of the nodes in the network. However, when /spl gamma/=0 and /spl delta/<3/2, the low-attenuation case, we show that there exist networks that can provide unbounded transport capacity for fixed total power, yielding zero energy priced communication. Examples show that nodes can profitably cooperate over large distances using coherence and multiuser estimation when the attenuation is low. These results are established by developing a coding scheme and an achievable rate for Gaussian multiple-relay channels, a result that may be of interest in its own right.
813Â citations
Cites background from "Ad hoc On-Demand Distance Vector (A..."
...This includes ad hoc networks, currently the subject of great interest, the protocols for which are under intense development [1], [2], [3], [4], [5], [6], [7]....
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28 Sep 2002
TL;DR: In this paper, the authors consider the problem of incorporating security mechanisms into routing protocols for ad hoc networks and develop a security mechanism to protect AODV routing information, which is also applicable to other similar routing protocols and about how a key management scheme could be used in conjunction with the solution.
Abstract: We consider the problem of incorporating security mechanisms into routing protocols for ad hoc networks. Canned security solutions like IPSec are not applicable. We look at AODV[21] in detail and develop a security mechanism to protect its routing information. We also briefly discuss whether our techniques would also be applicable to other similar routing protocols and about how a key management scheme could be used in conjunction with the solution that we provide.
809Â citations
TL;DR: The threat model for ad hoc routing is formulated and several specific attacks that can target the operation of a protocol are presented that can provide the basis for future research in this rapidly evolving area.
Abstract: In this paper we present a survey of secure ad hoc routing protocols for mobile wireless networks. A mobile ad hoc network is a collection of nodes that is connected through a wireless medium forming rapidly changing topologies. The widely accepted existing routing protocols designed to accommodate the needs of such self-organized networks do not address possible threats aiming at the disruption of the protocol itself. The assumption of a trusted environment is not one that can be realistically expected; hence several efforts have been made towards the design of a secure and robust routing protocol for ad hoc networks. We briefly present the most popular protocols that follow the table-driven and the source-initiated on-demand approaches. Based on this discussion we then formulate the threat model for ad hoc routing and present several specific attacks that can target the operation of a protocol. In order to analyze the proposed secure ad hoc routing protocols in a structured way we have classified them into five categories; solutions based on asymmetric cryptography, solutions based on symmetric cryptography, hybrid solutions, reputation-based solutions and a category of add-on mechanisms that satisfy specific security requirements. A comparison between these solutions can provide the basis for future research in this rapidly evolving area.
807Â citations
Cites methods from "Ad hoc On-Demand Distance Vector (A..."
...ARAN utilizes cryptographic certificates in order to achieve the security goals of authentication and non-repudiation....
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TL;DR: Simulation results show that the proposed schemes can significantly reduce contention at the MAC layer by achieving up to 70 percent reduction in packet loss rate while keeping end-to-end delay at acceptable levels for most VANET applications.
Abstract: Several multihop applications developed for vehicular ad hoc networks use broadcast as a means to either discover nearby neighbors or propagate useful traffic information to other vehicles located within a certain geographical area. However, the conventional broadcast mechanism may lead to the so-called broadcast storm problem, a scenario in which there is a high level of contention and collisions at the link layer due to an excessive number of broadcast packets. While this is a well-known problem in mobile ad hoc wireless networks, only a few studies have addressed this issue in the VANET context, where mobile hosts move along the roads in a certain limited set of directions as opposed to randomly moving in arbitrary directions within a bounded area. Unlike other existing works, we quantify the impact of broadcast storms in VANETs in terms of message delay and packet loss rate in addition to conventional metrics such as message reachability and overhead. Given that VANET applications are currently confined to using the DSRC protocol at the data link layer, we propose three probabilistic and timer-based broadcast suppression techniques: weighted p-persistence, slotted 1-persistence, and slotted p-persistence schemes, to be used at the network layer. Our simulation results show that the proposed schemes can significantly reduce contention at the MAC layer by achieving up to 70 percent reduction in packet loss rate while keeping end-to-end delay at acceptable levels for most VANET applications.
769Â citations
Cites background from "Ad hoc On-Demand Distance Vector (A..."
...Some routing protocols, however, have various features designed to avoid flooding the network and creating a broadcast storm [15, 16]....
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...As opposed to generic point-to-point MANET routing protocols [15, 16], vehicular networks have well defined applications that mostly favor broadcast protocols....
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12 Nov 2001
TL;DR: In this article, 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.
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207Â citations
"Ad hoc On-Demand Distance Vector (A..." refers methods in this paper
...This section defines other terminology used with AODV that is not already defined in [3]....
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