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Event detection for sensor networks /Xue, Wenwei. January 2007 (has links)
Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 139-148). Also available in electronic version.
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Enhancing interleaved authentication for multipath routing based in wireless sensor networks /Vu, Hai Trong, January 2006 (has links)
Thesis (M.S.) -- University of Texas at Dallas, 2006. / Includes vita. Includes bibliographical references (leaves 50-55)
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Foundations of coverage for wireless sensor networksKumar, Santosh, January 2006 (has links)
Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 139-143).
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Topology management protocols in ad hoc wireless sensor networksKim, Hogil 15 May 2009 (has links)
A wireless sensor network (WSN) is comprised of a few hundred or thousand au-tonomous sensor nodes spatially distributed over a particular region. Each sensornode is equipped with a wireless communication device, a small microprocessor, anda battery-powered energy source. Typically, the applications of WSNs such as habitatmonitoring, re detection, and military surveillance, require data collection, process-ing, and transmission among the sensor nodes. Due to their energy constraints andhostile environments, the main challenge in the research of WSN lies in prolongingthe lifetime of WSNs.In this dissertation, we present four dierent topology management protocols forK-coverage and load balancing to prolong the lifetime of WSNs.First, we present a Randomly Ordered Activation and Layering (ROAL) protocolfor K-coverage in a stationary WSN. The ROAL suggests a new model of layer cov-erage that can construct a K-covered WSN using the layer information received fromits previously activated nodes in the sensing distance. Second, we enhance the faulttolerance of layer coverage through a Circulation-ROAL (C-ROAL) protocol. Us-ing the layer number, the C-ROAL can activate each node in a round-robin fashionduring a predened period while conserving reconguration energy. Next, MobilityResilient Coverage Control (MRCC) is presented to assure K-coverage in the presence of mobility, in which a more practical and reliable model for K-coverage with nodalmobility is introduced. Finally, we present a Multiple-Connected Dominating Set(MCDS) protocol that can balance the network trac using an on-demand routingprotocol. The MCDS protocol constructs and manages multiple backbone networks,each of which is constructed with a connected dominating set (CDS) to ensure a con-nected backbone network. We describe each protocol, and compare the performanceof our protocols with Dynamic Source Routing (DSR) and/or existing K-coveragealgorithms through extensive simulations.The simulation results obtained by the ROAL protocol show that K-coverage canbe guaranteed with more than 95% coverage ratio, and signicantly extend networklifetime against a given WSN. We also observe that the C-ROAL protocol provides abetter reconguration method, which consumes only less than 1% of the recongura-tion energy in the ROAL protocol, with a greatly reduced packet latency. The MRCCprotocol, considering the mobility, achieves better coverage by 1.4% with 22% feweractive sensors than that of an existing coverage protocol for the mobility. The resultson the MCDS protocol show that the energy depletion ratio of nodes is decreasedconsequently, while the network throughput is improved by 35%.
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Game theoretic methods for networked sensors and dynamic spectrum accessMaskery, Michael 05 1900 (has links)
Automated devices enabled by wireless communications are deployed for a variety of purposes.
As they become more ubiquitous, their interaction becomes increasingly important
for coexistence when sharing a scarce resource, and for leveraging potential cooperation to achieve larger design goals.
This thesis investigates the use of game theory as a tool for design and analysis of networked systems of automated devices
in the areas of naval defence, wireless environmental monitoring through sensor networks, and cognitive radio wireless communications.
In the first part, decentralized operation of naval platforms deploying
electronic countermeasures against missile threats is studied.
The problem is formulated as a stochastic game in which platforms independently plan and execute
dynamic strategies to defeat threats in two situations: where coordination is impossible due to lack of
communications, and where platforms hold different objectives but can coordinate, according
to the military doctrine of Network Enabled Operations.
The result is a flexible, robust model for missile deflection for advanced naval groups.
Next, the problem of cooperative environmental monitoring and communication in energy-constrained wireless sensor networks
is considered from a game-theoretic perspective. This leads to novel protocols in which sensors cooperatively trade off
performance with energy consumption with low communication and complexity overhead.
Two key results are an on-line adaptive learning algorithm for tracking the correlated equilibrium set of a slowly
varying sensor deployment game, and an analysis of the equilibrium properties of threshold policies in a
game with noisy, correlated measurements.
Finally, the problem of dynamic spectrum access for systems of cognitive radios is considered. A game theoretic formulation
leads to a scheme for competitive bandwidth allocation which respects radios' individual interests while enforcing fairness
between users. An on-line adaptive learning scheme is again proposed for negotiating fair, equilibrium resource allocations, while
dynamically adjusting to changing conditions.
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Wireless Sensor Network SimulatorSriporamanont, Thammakit, Liming, Gu January 2006 (has links)
In the recent past, wireless sensor networks have been introduced to use in many applications. To design the networks, the factors needed to be considered are the coverage area, mobility, power consumption, communication capabilities etc. The challenging goal of our project is to create a simulator to support the wireless sensor network simulation. The network simulator (NS-2) which supports both wire and wireless networks is implemented to be used with the wireless sensor network. This implementation adds the sensor network classes which are environment, sensor agent and sensor application classes and modifies the existing classes of wireless network in NS- 2. This NS-2 based simulator is used to test routing protocols – Destination-Sequenced Distance Vector (DSDV), and Ad-Hoc On-Demand Distance Vector (AODV) as one part of simulations. Finally, the sensor network application models and the extension methods of this NS-2 based simulator for simulations in specific wireless sensor network applications are proposed.
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Topology management protocols in ad hoc wireless sensor networksKim, Hogil 15 May 2009 (has links)
A wireless sensor network (WSN) is comprised of a few hundred or thousand au-tonomous sensor nodes spatially distributed over a particular region. Each sensornode is equipped with a wireless communication device, a small microprocessor, anda battery-powered energy source. Typically, the applications of WSNs such as habitatmonitoring, re detection, and military surveillance, require data collection, process-ing, and transmission among the sensor nodes. Due to their energy constraints andhostile environments, the main challenge in the research of WSN lies in prolongingthe lifetime of WSNs.In this dissertation, we present four dierent topology management protocols forK-coverage and load balancing to prolong the lifetime of WSNs.First, we present a Randomly Ordered Activation and Layering (ROAL) protocolfor K-coverage in a stationary WSN. The ROAL suggests a new model of layer cov-erage that can construct a K-covered WSN using the layer information received fromits previously activated nodes in the sensing distance. Second, we enhance the faulttolerance of layer coverage through a Circulation-ROAL (C-ROAL) protocol. Us-ing the layer number, the C-ROAL can activate each node in a round-robin fashionduring a predened period while conserving reconguration energy. Next, MobilityResilient Coverage Control (MRCC) is presented to assure K-coverage in the presence of mobility, in which a more practical and reliable model for K-coverage with nodalmobility is introduced. Finally, we present a Multiple-Connected Dominating Set(MCDS) protocol that can balance the network trac using an on-demand routingprotocol. The MCDS protocol constructs and manages multiple backbone networks,each of which is constructed with a connected dominating set (CDS) to ensure a con-nected backbone network. We describe each protocol, and compare the performanceof our protocols with Dynamic Source Routing (DSR) and/or existing K-coveragealgorithms through extensive simulations.The simulation results obtained by the ROAL protocol show that K-coverage canbe guaranteed with more than 95% coverage ratio, and signicantly extend networklifetime against a given WSN. We also observe that the C-ROAL protocol provides abetter reconguration method, which consumes only less than 1% of the recongura-tion energy in the ROAL protocol, with a greatly reduced packet latency. The MRCCprotocol, considering the mobility, achieves better coverage by 1.4% with 22% feweractive sensors than that of an existing coverage protocol for the mobility. The resultson the MCDS protocol show that the energy depletion ratio of nodes is decreasedconsequently, while the network throughput is improved by 35%.
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Stealthy attacks and defense strategies in competing sensor networksCzarlinska, Aleksandra 15 May 2009 (has links)
The fundamental objective of sensor networks underpinning a variety of applications
is the collection of reliable information from the surrounding environment.
The correctness of the collected data is especially important in applications involving
societal welfare and safety, in which the acquired information may be utilized by
end-users for decision-making. The distributed nature of sensor networks and their
deployment in unattended and potentially hostile environments, however, renders this
collection task challenging for both scalar and visual data.
In this work we propose and address the twin problem of carrying out and defending
against a stealthy attack on the information gathered by a sensor network at
the physical sensing layer as perpetrated by a competing hostile network. A stealthy
attack in this context is an intelligent attempt to disinform a sensor network in a
manner that mitigates attack discovery. In comparison with previous sensor network
security studies, we explicitly model the attack scenario as an active competition between
two networks where difficulties arise from the pervasive nature of the attack,
the possibility of tampering during data acquisition prior to encryption, and the lack
of prior knowledge regarding the characteristics of the attack.
We examine the problem from the perspective of both the hostile and the legitimate
network. The interaction between the networks is modeled as a game where
a stealth utility is derived and shown to be consistent for both players in the case of stealthy direct attacks and stealthy cross attacks. Based on the stealth utility,
the optimal attack and defense strategies are obtained for each network. For the
legitimate network, minimization of the attacker’s stealth results in the possibility of
attack detection through established paradigms and the ability to mitigate the power
of the attack. For the hostile network, maximization of the stealth utility translates
into the optimal attack avoidance. This attack avoidance does not require active
communication among the hostile nodes but rather relies on a level of coordination
which we quantify. We demonstrate the significance and effectiveness of the solution
for sensor networks acquiring scalar and multidimensional data such as surveillance
sequences and relate the results to existing image sensor networks. Finally we discuss
the implications of these results for achieving secure event acquisition in unattended
environments.
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A congestion control scheme for wireless sensor networksXiong, Yunli 29 August 2005 (has links)
In wireless sensor networks (WSN), nodes have very limited power due to
hardware constraints. Packet losses and retransmissions resulting from congestion
cost precious energy and shorten the lifetime of sensor nodes. This problem motivates
the need for congestion control mechanisms in WSN.
In this thesis, an observation of multiple non-empty queues in sensor networks
is first reported. Other aspects affected by congestion like queue length, delay and
packet loss are also studied. The simulation results show that the number of occupied
queues along a path can be used to detect congestion.
Based on the above result, a congestion control scheme for the transport layer
is proposed in this thesis. It is composed of three parts: (i) congestion detection
by tracking the number of non-empty queues; (ii) On-demand midway non-binary
explicit congestion notification (CN) feedback; and (iii) Adaptive rate control based
on additive increase and multiplicative decrease (AIMD).
This scheme has been implemented in ns2. Extensive simulations have been
conducted to evaluate it. Results show that it works well in mitigating and avoiding
congestion and achieves good performance in terms of energy dissipation, latency and
transmission effciency.
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Neighbor-Aware Gossip-Based Broadcasting Scheme for Wireless Sensor NetworksLin, Yen-pang 01 February 2010 (has links)
In wireless sensor networks (WSNs), flooding is usually adopted by broadcast services to disseminate broadcast messages. However, flooding produces an excessive number of unnecessary control packets, markedly increasing overhead. This work proposes a new gossip-based scheme, in which nodes forward broadcast messages with dynamic probability to decrease the number of redundant messages and thereby improve energy efficiency. By using the novel probability table and adjustment mechanism based on neighbor conditions, nodes can obtain a suitable gossip probability. Furthermore, this work considers some special cases of uneven sensor deployment such as that contains nodes with a low degree. An efficient algorithm was also developed to maintain the stability of the proposed protocol. Hence, the proposed approach can deal with various topologies and node failure. Simulations demonstrate that applying the proposed scheme to control messages forwarding improves performance compared with that of existing gossip-based broadcasting schemes.
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