19,653 research outputs found
Energy efficient data collection and dissemination protocols in self-organised wireless sensor networks
Wireless sensor networks (WSNs) are used for event detection and data collection in
a plethora of environmental monitoring applications. However a critical factor limits
the extension of WSNs into new application areas: energy constraints. This thesis
develops self-organising energy efficient data collection and dissemination protocols in
order to support WSNs in event detection and data collection and thus extend the use
of sensor-based networks to many new application areas.
Firstly, a Dual Prediction and Probabilistic Scheduler (DPPS) is developed. DPPS
uses a Dual Prediction Scheme combining compression and load balancing techniques
in order to manage sensor usage more efficiently. DPPS was tested and evaluated
through computer simulations and empirical experiments. Results showed that DPPS
reduces energy consumption in WSNs by up to 35% while simultaneously maintaining
data quality and satisfying a user specified accuracy constraint.
Secondly, an Adaptive Detection-driven Ad hoc Medium Access Control (ADAMAC)
protocol is developed. ADAMAC limits the Data Forwarding Interruption problem
which causes increased end-to-end delay and energy consumption in multi-hop sensor
networks. ADAMAC uses early warning alarms to dynamically adapt the sensing
intervals and communication periods of a sensor according to the likelihood of any
new events occurring. Results demonstrated that compared to previous protocols such
as SMAC, ADAMAC dramatically reduces end-to-end delay while still limiting energy
consumption during data collection and dissemination. The protocols developed in this thesis, DPPS and ADAMAC, effectively alleviate
the energy constraints associated with WSNs and will support the extension of sensorbased
networks to many more application areas than had hitherto been readily possible
Pheromone-based In-Network Processing for wireless sensor network monitoring systems
Monitoring spatio-temporal continuous fields using wireless sensor networks (WSNs) has emerged as a novel solution. An efficient data-driven routing mechanism for sensor querying and information gathering in large-scale WSNs is a challenging problem. In particular, we consider the case of how to query the sensor network information with the minimum energy cost in scenarios where a small subset of sensor nodes has relevant readings. In order to deal with this problem, we propose a Pheromone-based In-Network Processing (PhINP) mechanism. The proposal takes advantages of both a pheromone-based iterative strategy to direct queries towards nodes with relevant information and query- and response-based in-network filtering to reduce the number of active nodes. Additionally, we apply reinforcement learning to improve the performance. The main contribution of this work is the proposal of a simple and efficient mechanism for information discovery and gathering. It can reduce the messages exchanged in the network, by allowing some error, in order to maximize the network lifetime. We demonstrate by extensive simulations that using PhINP mechanism the query dissemination cost can be reduced by approximately 60% over flooding, with an error below 1%, applying the same in-network filtering strategy.Fil: Riva, Guillermo Gaston. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Finochietto, Jorge Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Estudios Avanzados en Ingeniería y Tecnología. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Estudios Avanzados en Ingeniería y Tecnología; Argentin
An adaptive directed query dissemination scheme for wireless sensor networks
This paper describes a directed query dissemination scheme, DirQ that routes queries to the appropriate source nodes based on both constant and dynamic-valued attributes such as sensor types and sensor values. Unlike certain other query dissemination schemes, location information is not essential for the operation of DirQ. DirQ uses only locally available information in order to route queries accurately. Nodes running DirQ are able to adapt autonomously to changes in network topology due to certain cross-layer features that allow it to exchange information with the underlying MAC protocol. DirQ allows nodes to autonomously control the rate of sending update messages in order to keep the routing information updated. The rate of sending updates is dependent on both the number of queries injected into the network and the rate of variation of the measured physical parameter. Our results show that DirQ spends between 45% and 55% the cost of flooding
Doped Fountain Coding for Minimum Delay Data Collection in Circular Networks
This paper studies decentralized, Fountain and network-coding based
strategies for facilitating data collection in circular wireless sensor
networks, which rely on the stochastic diversity of data storage. The goal is
to allow for a reduced delay collection by a data collector who accesses the
network at a random position and random time. Data dissemination is performed
by a set of relays which form a circular route to exchange source packets. The
storage nodes within the transmission range of the route's relays linearly
combine and store overheard relay transmissions using random decentralized
strategies. An intelligent data collector first collects a minimum set of coded
packets from a subset of storage nodes in its proximity, which might be
sufficient for recovering the original packets and, by using a message-passing
decoder, attempts recovering all original source packets from this set.
Whenever the decoder stalls, the source packet which restarts decoding is
polled/doped from its original source node. The random-walk-based analysis of
the decoding/doping process furnishes the collection delay analysis with a
prediction on the number of required doped packets. The number of doped packets
can be surprisingly small when employed with an Ideal Soliton code degree
distribution and, hence, the doping strategy may have the least collection
delay when the density of source nodes is sufficiently large. Furthermore, we
demonstrate that network coding makes dissemination more efficient at the
expense of a larger collection delay. Not surprisingly, a circular network
allows for a significantly more (analytically and otherwise) tractable
strategies relative to a network whose model is a random geometric graph
Design and analysis of a beacon-less routing protocol for large volume content dissemination in vehicular ad hoc networks
Largevolumecontentdisseminationispursuedbythegrowingnumberofhighquality applications for Vehicular Ad hoc NETworks(VANETs), e.g., the live road surveillance service and the video-based overtaking assistant service. For the highly dynamical vehicular network topology, beacon-less routing protocols have been proven to be efficient in achieving a balance between the system performance and the control overhead. However, to the authors’ best knowledge, the routing design for large volume content has not been well considered in the previous work, which will introduce new challenges, e.g., the enhanced connectivity requirement for a radio link. In this paper, a link Lifetime-aware Beacon-less Routing Protocol (LBRP) is designed for large volume content delivery in VANETs. Each vehicle makes the forwarding decision based on the message header information and its current state, including the speed and position information. A semi-Markov process analytical model is proposed to evaluate the expected delay in constructing one routing path for LBRP. Simulations show that the proposed LBRP scheme outperforms the traditional dissemination protocols in providing a low end-to-end delay. The analytical model is shown to exhibit a good match on the delay estimation with Monte Carlo simulations, as well
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