60 research outputs found
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Optimizing the beacon exchange rate for proactive autonomic configuration in ubiquitous MANETs
Proactive self-configuration is indispensable for MANETs like ubiquitous sensor networks (USNs), as component devices of the network are usually exposed to natural or man-made disasters due to the hostile deployment and ad hoc nature of the USNs. Network state beacons (NSBs) are exchanged among the key nodes of the network for crucial and effective monitoring of the network for steady state operation. The rate of beacon exchange (F/sub E/) and its contents, define the time and nature of the proactive action. Therefore it is very important to optimize these parameters to tune the functional response of the USN. This paper presents a comprehensive model for monitoring and proactively reconfiguring the network by optimizing the F/sub E/. The results confirm the improved throughput while maintaining QoS over longer periods of network operation
Distributed and Load-Adaptive Self Configuration in Sensor Networks
Proactive self-configuration is crucial for MANETs such as sensor networks, as these are often deployed in hostile environments and are ad hoc in nature. The dynamic architecture of the network is monitored by exchanging so-called Network State Beacons (NSBs) between key network nodes. The Beacon Exchange rate and the network state define both the time and nature of a proactive action to combat network performance degradation at a time of crisis. It is thus essential to optimize these parameters for the dynamic load profile of the network. This paper presents a novel distributed adaptive optimization Beacon Exchange selection model which considers distributed network load for energy efficient monitoring and proactive reconfiguration of the network. The results show an improvement of 70% in throughput, while maintaining a guaranteed quality-of- service for a small control-traffic overhead
Optimising Network Control Traffic in Resource Constrained MANETS
The exchange of Network State Beacons (NSBs) is crucial to monitoring the dynamic state of MANETs like sensor networks. The rate of beacon exchange (FX) and the network state define both the time and nature of a proactive action to reconfigure the network in order to combat network performance degradation at a time of crisis. It is thus essential to select the FX within optimized bounds, so that minimal control traffic is incurred due to state maintenance and reconfiguration activities. This paper presents a novel distributed model that selects optimized bounds for FX selection and adapts dynamically to the load profile of the network for energy efficient monitoring and proactive reconfiguration
Adaptive Self-Configuration for Distributed Load in Sensor Networks
The dynamic architecture of the network is monitored by exchanging so-called Network State Beacons (NSBs) between key network nodes. The Beacon Exchange rate and the network state define both the time and nature of a proactive action to combat network performance degradation at a time of crisis. It is thus essential to select and update the beacon exchange rate (FX) according to the variations in the load profile of the network. This paper presents a novel localized method that for selecting and updating the FX by adapting to the network load and energy constraints. The results indicating that the model reconfigures the network more effectively to achieve higher throughput as well as greater network integrity, with minimal resource overheads
An adaptive multi-hop routing with IoT abstraction for minimizing delay-node capacity trade-offs in mobile ad-hoc network
Delay and node capacity are incompatible mobile ad hoc constraints because of the network's versatility and self-disciplined design. It is a challenging problem to maximize the trade-off between the above mobility correlation factors. This manuscript proposes an adaptive multi-hop routing (A.M.R.) for mobile ad-hoc network (MANET) to minimize the trade-off by integrating the internet of things (IoT). IoT nodes' smart computing and offloading abilities are extended to ad-hoc nodes to improve routing and transmission. Dor MANET nodes in route exploration, neighbor selection, and data transmission, the beneficial features of IoT include enhanced decision making. The traditional routing protocols use IoT at the time of the neighbor discovery process in updating the routing table and localization. The harmonizing technologies with their extended support improve the performance of MANETs has been estimated. The proposed method achieves better throughput (14.16 Mbps), delay (0.118), packet drop (126), and overhead (36 packets) when compared to existing methods
NEURON: Enabling Autonomicity in Wireless Sensor Networks
Future Wireless Sensor Networks (WSNs) will be ubiquitous, large-scale networks interconnected with the existing IP infrastructure. Autonomic functionalities have to be designed in order to reduce the complexity of their operation and management, and support the dissemination of knowledge within a WSN. In this paper a novel protocol for energy efficient deployment, clustering and routing in WSNs is proposed that focuses on the incorporation of autonomic functionalities in the existing approaches. The design of the protocol facilitates the design of innovative applications and services that are based on overlay topologies created through cooperation among the sensor nodes
Mobile Ad Hoc Networks
Guiding readers through the basics of these rapidly emerging networks to more advanced concepts and future expectations, Mobile Ad hoc Networks: Current Status and Future Trends identifies and examines the most pressing research issues in Mobile Ad hoc Networks (MANETs). Containing the contributions of leading researchers, industry professionals, and academics, this forward-looking reference provides an authoritative perspective of the state of the art in MANETs. The book includes surveys of recent publications that investigate key areas of interest such as limited resources and the mobility of mobile nodes. It considers routing, multicast, energy, security, channel assignment, and ensuring quality of service. Also suitable as a text for graduate students, the book is organized into three sections: Fundamentals of MANET Modeling and Simulation—Describes how MANETs operate and perform through simulations and models Communication Protocols of MANETs—Presents cutting-edge research on key issues, including MAC layer issues and routing in high mobility Future Networks Inspired By MANETs—Tackles open research issues and emerging trends Illustrating the role MANETs are likely to play in future networks, this book supplies the foundation and insight you will need to make your own contributions to the field. It includes coverage of routing protocols, modeling and simulations tools, intelligent optimization techniques to multicriteria routing, security issues in FHAMIPv6, connecting moving smart objects to the Internet, underwater sensor networks, wireless mesh network architecture and protocols, adaptive routing provision using Bayesian inference, and adaptive flow control in transport layer using genetic algorithms
Natural computing for vehicular networks
La presente tesis aborda el diseño inteligente de soluciones para el despliegue de redes vehiculares ad-hoc (vehicular ad hoc networks, VANETs). Estas son redes de comunicación inalámbrica formada principalmente por vehÃculos y elementos de infraestructura vial. Las VANETs ofrecen la oportunidad para desarrollar aplicaciones revolucionarias en el ámbito de la seguridad y eficiencia vial. Al ser un dominio tan novedoso, existe una serie de cuestiones abiertas, como el diseño de la infraestructura de estaciones base necesaria y el encaminamiento (routing) y difusión (broadcasting) de paquetes de datos, que todavÃa no han podido resolverse empleando estrategias clásicas. Es por tanto necesario crear y estudiar nuevas técnicas que permitan de forma eficiente, eficaz, robusta y flexible resolver dichos problemas.
Este trabajo de tesis doctoral propone el uso de computación inspirada en la naturaleza o Computación Natural (CN) para tratar algunos de los problemas más importantes en el ámbito de las VANETs, porque representan una serie de algoritmos versátiles, flexibles y eficientes para resolver problemas complejos. Además de resolver los problemas VANET en los que nos enfocamos, se han realizado avances en el uso de estas técnicas para que traten estos problemas de forma más eficiente y eficaz. Por último, se han llevado a cabo pruebas reales de concepto empleando vehÃculos y dispositivos de comunicación reales en la ciudad de Málaga (España).
La tesis se ha estructurado en cuatro grandes fases. En la primera fase, se han estudiado los principales fundamentos en los que se basa esta tesis. Para ello se hizo un estudio exhaustivo sobre las tecnologÃas que emplean las redes vehiculares, para asÃ, identificar sus principales debilidades. A su vez, se ha profundizado en el análisis de la CN como herramienta eficiente para resolver problemas de optimización complejos, y de cómo utilizarla en la resolución de los problemas en VANETs. En la segunda fase, se han abordado cuatro problemas de optimización en redes vehiculares: la transferencia de archivos, el encaminamiento (routing) de paquetes, la difusión (broadcasting) de mensajes y el diseño de la infraestructura de estaciones base necesaria para desplegar redes vehiculares. Para la resolución de dichos problemas se han propuesto diferentes algoritmos CN que se clasifican en algoritmos evolutivos (evolutionary algorithms, EAs), métodos de inteligencia de enjambre (swarm intelligence, SI) y enfriamiento simulado (simulated annealing, SA). Los resultados obtenidos han proporcionado protocolos de han mejorado de forma significativa las comunicaciones en VANETs. En la tercera y última fase, se han realizado experimentos empleando vehÃculos reales circulando por las carreteras de Málaga y que se comunicaban entre sÃ. El principal objetivo de estas pruebas ha sido el validar las mejoras que presentan los protocolos que se han optimizado empleando CN. Los resultados obtenidos de las fases segunda y tercera confirman la hipótesis de trabajo, que la CN es una herramienta eficiente para tratar el diseño inteligente en redes vehiculares
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Optimising routing and trustworthiness of ad hoc networks using swarm intelligence
This thesis was submitted for the degree of Doctor of Philsophy and awarded by Brunel UniversityThis thesis proposes different approaches to address routing and security of MANETs using swarm technology. The mobility and infrastructure-less of MANET as well as nodes misbehavior compose great challenges to routing and security protocols of such a network. The first approach addresses the problem of channel assignment in multichannel ad hoc networks with limited number of interfaces, where stable route are more preferred to be selected. The channel selection is based on link quality between the nodes. Geographical information is used with mapping algorithm in order to estimate and predict the links’ quality and routes life time, which is combined with Ant Colony Optimization (ACO) algorithm to find most stable route with high data rate. As a result, a better utilization of the channels is performed where the throughput increased up to 74% over ASAR protocol. A new smart data packet routing protocol is developed based on the River Formation Dynamics (RFD) algorithm. The RFD algorithm is a subset of swarm intelligence which mimics how rivers are created in nature. The protocol is a distributed swarm learning approach where data packets are smart enough to guide themselves through best available route in the network. The learning information is distributed throughout the nodes of the network. This information can be used and updated by successive data packets in order to maintain and find better routes. Data packets act like swarm agents (drops) where they carry their path information and update routing information without the need for backward agents. These data packets modify the routing information based on different network metrics. As a result, data packet can guide themselves through better routes.
In the second approach, a hybrid ACO and RFD smart data packet routing protocol is developed where the protocol tries to find shortest path that is less congested to the destination. Simulation results show throughput improvement by 30% over AODV protocol and 13% over AntHocNet. Both delay and jitter have been improved more than 96% over AODV protocol. In order to overcome the problem of source routing introduced due to the use of the ACO algorithm, a solely RFD based distance vector protocol has been developed as a third approach. Moreover, the protocol separates reactive learned information from proactive learned information to add more reliability to data routing. To minimize the power consumption introduced due to the hybrid nature of the RFD routing protocol, a forth approach has been developed. This protocol tackles the problem of power consumption and adds packets delivery power minimization to the protocol based on RFD algorithm.
Finally, a security model based on reputation and trust is added to the smart data packet protocol in order to detect misbehaving nodes. A trust system has been built based on the privilege offered by the RFD algorithm, where drops are always moving from higher altitude to lower one. Moreover, the distributed and undefined nature of the ad hoc network forces the nodes to obligate to cooperative behaviour in order not to be exposed. This system can easily and quickly detect misbehaving nodes according to altitude difference between active intermediate nodes
Communication between nodes for autonomic and distributed management
Doutoramento conjunto MAPi em InformáticaOver the last decade, the most widespread approaches for traditional management
were based on the Simple Network Management Protocol (SNMP) or Common
Management Information Protocol (CMIP). However, they both have several problems
in terms of scalability, due to their centralization characteristics. Although
the distributed management approaches exhibit better performance in terms of
scalability, they still underperform regarding communication costs, autonomy, extensibility,
exibility, robustness, and cooperation between network nodes. The
cooperation between network nodes normally requires excessive overheads for synchronization
and dissemination of management information in the network. For
emerging dynamic and large-scale networking environments, as envisioned in Next
Generation Networks (NGNs), exponential growth in the number of network devices
and mobile communications and application demands is expected. Thus, a
high degree of management automation is an important requirement, along with
new mechanisms that promote it optimally and e ciently, taking into account the
need for high cooperation between the nodes. Current approaches for self and autonomic
management allow the network administrator to manage large areas, performing
fast reaction and e ciently facing unexpected problems. The management
functionalities should be delegated to a self-organized plane operating within the
network, that decrease the network complexity and the control information ow,
as opposed to centralized or external servers. This Thesis aims to propose and
develop a communication framework for distributed network management which
integrates a set of mechanisms for initial communication, exchange of management
information, network (re) organization and data dissemination, attempting
to meet the autonomic and distributed management requirements posed by NGNs.
The mechanisms are lightweight and portable, and they can operate in di erent
hardware architectures and include all the requirements to maintain the basis for
an e cient communication between nodes in order to ensure autonomic network
management. Moreover, those mechanisms were explored in diverse network conditions
and events, such as device and link errors, di erent tra c/network loads
and requirements. The results obtained through simulation and real experimentation
show that the proposed mechanisms provide a lower convergence time, smaller
overhead impact in the network, faster dissemination of management information,
increase stability and quality of the nodes associations, and enable the support for
e cient data information delivery in comparison to the base mechanisms analyzed.
Finally, all mechanisms for communication between nodes proposed in this Thesis,
that support and distribute the management information and network control
functionalities, were devised and developed to operate in completely decentralized
scenarios.Durante a última década, protocolos como Simple Network Management Protocol
(SNMP) ou Common Management Information Protocol (CMIP) foram as abordagens
mais comuns para a gestão tradicional de redes. Essas abordagens têm
vários problemas em termos de escalabilidade, devido à s suas caracterÃsticas de
centralização. Apresentando um melhor desempenho em termos de escalabilidade,
as abordagens de gestão distribuÃda, por sua vez, são vantajosas nesse sentido,
mas também apresentam uma série de desvantagens acerca do custo elevado de
comunicação, autonomia, extensibilidade, exibilidade, robustez e cooperação entre
os nós da rede. A cooperação entre os nós presentes na rede é normalmente
a principal causa de sobrecarga na rede, uma vez que necessita de colectar, sincronizar
e disseminar as informações de gestão para todos os nós nela presentes.
Em ambientes dinâmicos, como é o caso das redes atuais e futuras, espera-se um
crescimento exponencial no número de dispositivos, associado a um grau elevado
de mobilidade dos mesmos na rede. Assim, o grau elevado de funções de automatiza
ção da gestão da rede é uma exigência primordial, bem como o desenvolvimento
de novos mecanismos e técnicas que permitam essa comunicação de forma optimizada
e e ciente. Tendo em conta a necessidade de elevada cooperação entre
os elementos da rede, as abordagens atuais para a gestão autonómica permitem
que o administrador possa gerir grandes áreas de forma rápida e e ciente frente
a problemas inesperados, visando diminuir a complexidade da rede e o uxo de
informações de controlo nela gerados. Nas gestões autonómicas a delegação de
operações da rede é suportada por um plano auto-organizado e não dependente
de servidores centralizados ou externos. Com base nos tipos de gestão e desa os
acima apresentados, esta Tese tem como principal objetivo propor e desenvolver
um conjunto de mecanismos necessários para a criação de uma infra-estrutura
de comunicação entre nós, na tentativa de satisfazer as exigências da gestão auton
ómica e distribuÃda apresentadas pelas redes de futura geração. Nesse sentido,
mecanismos especà cos incluindo inicialização e descoberta dos elementos da rede,
troca de informação de gestão, (re) organização da rede e disseminação de dados
foram elaborados e explorados em diversas condições e eventos, tais como: falhas
de ligação, diferentes cargas de tráfego e exigências de rede. Para além disso, os
mecanismos desenvolvidos são leves e portáveis, ou seja, podem operar em diferentes
arquitecturas de hardware e contemplam todos os requisitos necessários para
manter a base de comunicação e ciente entre os elementos da rede. Os resultados
obtidos através de simulações e experiências reais comprovam que os mecanismos
propostos apresentam um tempo de convergência menor para descoberta e troca
de informação, um menor impacto na sobrecarga da rede, disseminação mais rápida
da informação de gestão, aumento da estabilidade e a qualidade das ligações entre
os nós e entrega e ciente de informações de dados em comparação com os mecanismos
base analisados. Finalmente, todos os mecanismos desenvolvidos que fazem
parte da infrastrutura de comunicação proposta foram concebidos e desenvolvidos
para operar em cenários completamente descentralizados
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