6 research outputs found
Symbiot: Congestion-Driven Multi-resource Fairness for Multi-user Sensor Networks
© 2015 IEEE.In this paper, we study the problem of multi-resource fairness in multi-user sensor networks with heterogeneous and time-varying resources. Particularly we focus on data gathering applications run on Wireless Sensor Networks (WSNs) or Internet of Things (IoT) in which users require to run a serious of sensing operations with various resource requirements. We consider both the resource demands of sensing tasks, and data forwarding tasks needed to establish multi-hop relay communications. By exploiting graph theory, queueing theory and the notion of dominant resource shares, we develop Symbiot, a light-weight, distributed algorithm that ensures multi-resource fairness between these users. With Symbiot, nodes can independently schedule its resources while maintaining network-level resource fairness through observing traffic congestion levels. Large-scale simulations based Contiki OS and Cooja network emulator show the effectiveness of Symbiot in adaptively utilizing available resources and reducing average completion times
Amostragem Adaptativa em Redes de Sensores
Uma nova área tecnológica está em crescente desenvolvimento. Esta área, denominada de
internet das coisas, surge na necessidade de interligar vários objetos para uma melhoria a
nível de serviços ou necessidades por parte dos utilizadores. Esta dissertação concentra-se
numa área específica da tecnologia internet das coisas que é a sensorização. Esta rede de
sensorização é implementada pelo projeto europeu denominado de Future Cities [1] onde se
cria uma infraestrutura de investigação e validação de projetos e serviços inteligentes na
cidade do Porto. O trabalho realizado nesta dissertação insere-se numa das plataformas
existentes nessa rede de sensorização: a plataforma de sensores ambientais intitulada de
UrbanSense. Estes sensores ambientais que estão incorporados em Data Collect Unit
(DCU), também denominados por nós, medem variáveis ambientais tais como a temperatura,
humidade, ozono e monóxido de carbono. No entanto, os nós têm recursos limitados em
termos de energia, processamento e memória. Apesar das grandes evoluções a nível de
armazenamento e de processamento, a nível energético, nomeadamente nas baterias, não
existe ainda uma evolução tão notável, limitando a sua operacionalidade [2].
Esta tese foca-se, essencialmente, na melhoria do desempenho energético da rede de
sensores UrbanSense. A principal contribuição é uma adaptação do protocolo de redes Ad
Hoc OLSR (Optimized Link State Routing Protocol) para ser usado por nós alimentados a
energia renovável, de forma a aumentar a vida útil dos nós da rede de sensorização. Com
esta contribuição é possível obter um maior número de dados durante períodos de tempo
mais longos, aproximadamente 10 horas relativamente às 7 horas anteriores, resultando
numa maior recolha e envio dos mesmos com uma taxa superior, cerca de 500 KB/s.
Existindo deste modo uma aproximação analítica dos vários parâmetros existentes na rede
de sensorização. Contudo, o aumento do tempo de vida útil dos nós sensores com recurso à
energia renovável, nomeadamente, energia solar, incrementa o seu peso e tamanho que limita
a sua mobilidade. Com o referido acréscimo a determinar e a limitar a sua mobilidade
exigindo, por isso, um planeamento prévio da sua localização. Numa primeira fase do
trabalho analisou-se o consumo da DCU, visto serem estes a base na infraestrutura e
comunicando entre si por WiFi ou 3G. Após uma análise dos protocolos de routing com
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suporte para parametrização energética, a escolha recaiu sobre o protocolo OLSR devido à
maturidade e compatibilidade com o sistema atual da DCU, pois apesar de existirem outros
protocolos, a implementação dos mesmos, não se encontram disponível como software
aberto.
Para a validação do trabalho realizado na presente dissertação, é realizado um ensaio prévio
sem a energia renovável, para permitir caracterização de limitações do sistema. Com este
ensaio, tornou-se possível verificar a compatibilidade entre os vários materiais e ajustamento
de estratégias. Num segundo teste de validação é concretizado um ensaio real do sistema
com 4 nós a comunicar, usando o protocolo com eficiência energética. O protocolo é
avaliado em termos de aumento do tempo de vida útil do nó e da taxa de transferência.
O desenvolvimento da análise e da adaptação do protocolo de rede Ad Hoc oferece uma
maior longevidade em termos de tempo de vida útil, comparando ao que existe durante o
processamento de envio de dados. Apesar do tempo de longevidade ser inferior, quando o
parâmetro energético se encontra por omissão com o fator 3, a realização da adaptação do
sistema conforme a energia, oferece uma taxa de transferência maior num período mais
longo. Este é um fator favorável para a abertura de novos serviços de envio de dados em
tempo real ou envio de ficheiros com um tamanho mais elevado.A new technology area is in increasing development, this area called Internet of things arises
the need to link various objects to raising the level of services or needs from users. This
dissertation focuses on a specific area of internet technology of the things that is sensing.
This sensing network is implemented by the European project called Future Cities [1] where
you create a research infrastructure and validation of smart projects and services in Porto.
The work done in this thesis is part of an existing platforms that network sensing: the
environmental sensor platform titled UrbanSense. These environmental sensors are
incorporated into Collect Data Unit (DCU), also known by us, measure environmental
variables such as temperature, humidity, ozone and carbon monoxide. However, we have
limited resources in terms of power, processing and memory. Despite major developments
in terms of storage and processing, the energy level, especially in batteries, there is still such
a remarkable evolution, limiting their operation.
This thesis will focus on improving the energy performance of UrbanSense sensor network.
The main contribution is an adaptation of networks Ad Hoc protocol OLSR (Optimized Link
State Routing Protocol) to be used by us powered by renewable energy, in order to extend
the life of the nodes of the sensing network. With this contribution is possible to get more
data for longer periods of time, approximately 10 hours, resulting in increased collection and
sending of the same with a rate greater than about 500 KB / s. There an analytical approach
of the various parameters in the sensing network. However, increasing the lifetime of the
sensor nodes using renewable energy, particularly solar energy increases its weight and size
which limits its mobility. With that extra to determine and limit their mobility demanding,
so advance planning on your location. In a first phase of the study analyzed the consumption
of DCU, as these are the basis on infrastructure and communicating with each other by WiFi
or 3G. After an analysis of routing protocols that support energy parameter, the choice fell
on the OLSR protocol due to maturity and compatibility with the current system of DCU,
because although there are other protocols, their implementation, if any, is not available as
open source software.
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For the validation work performed in this work is done, a test without renewable energy, for
the characterization of system limitations. With this test, it became possible to verify the
compatibility between the various materials and adjustment strategies. In a second validation
test is implemented an actual test system with 4 nodes to communicate using the protocol
with energy efficiency. The protocol is evaluated in terms of increasing the lifetime of the
node and throughput.
The development of the analysis and adaptation of the Ad Hoc network protocol offers
greater longevity in terms of lifetime compared when there is upstream processing. Despite
the longevity of time is less than when the energy parameter is by default with the factor 3,
the realization of the system adaptation as energy offers greater throughput over a longer
period. This is a favorable factor for the opening of new real-time data push services or
sending files with a higher size
Distributed Networking in Autonomic Solar Powered Wireless Sensor Networks
Recent advances in solar harvesting technologies pave the way for sustainable environmental-monitoring applications in the emerging solar powered wireless sensor networks (SP-WSNs). The complexities associated with the low-resourced, highly-dynamic, and vulnerable sensor nodes operating in potentially unattended or hostile environments require a high degree of self-management and automation. Guided by autonomic communication principles, this paper presents AutoSP-WSN, a novel distributed framework to achieve sustainable data collection while also optimizing end-to-end network performance for SP-WSNs. Initially, we present the energy-aware support component that provides reliable energy monitoring and prediction. This drives the power management component, which is adaptive to time-varying solar power, avoiding battery exhaustion as well as maximizing the per-node utility. Finally, to demonstrate the key design issues of the network protocol component, we propose two self-adaptive network protocols, a routing protocol SP-BCP and a rate control scheme PEA-DLEX. We show that the individual components seamlessly highly integrate as a whole, and the AutoSP-WSN framework exhibits the properties of context-awareness, distributed operation, self-configuration, self-optimization, self-protection and self-healing. Through extensive experiments on a real SP-WSN platform, and hardware-driven simulations, we show that the proposed schemes achieve substantial improvements over previous work, in terms of reliability, sustainable operation, and network utility
Distributed Networking in Autonomic Solar Powered Wireless Sensor Networks
Recent advances in solar harvesting technologies pave the way for sustainable environmental-monitoring applications in the emerging solar powered wireless sensor networks (SP-WSNs). The complexities associated with the low-resourced, highly-dynamic, and vulnerable sensor nodes operating in potentially unattended or hostile environments require a high degree of self-management and automation. Guided by autonomic communication principles, this paper presents AutoSP-WSN, a novel distributed framework to achieve sustainable data collection while also optimizing end-to-end network performance for SP-WSNs. Initially, we present the energy-aware support component that provides reliable energy monitoring and prediction. This drives the power management component, which is adaptive to time-varying solar power, avoiding battery exhaustion as well as maximizing the per-node utility. Finally, to demonstrate the key design issues of the network protocol component, we propose two self-adaptive network protocols, a routing protocol SP-BCP and a rate control scheme PEA-DLEX. We show that the individual components seamlessly highly integrate as a whole, and the AutoSP-WSN framework exhibits the properties of context-awareness, distributed operation, self-configuration, self-optimization, self-protection and self-healing. Through extensive experiments on a real SP-WSN platform, and hardware-driven simulations, we show that the proposed schemes achieve substantial improvements over previous work, in terms of reliability, sustainable operation, and network utility