Dissertations / Theses on the topic 'Wireless sensor networking'
To see the other types of publications on this topic, follow the link: Wireless sensor networking.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Wireless sensor networking.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Spinden, David, Jeffrey Jasper, and Kurt Kosbar. "Comparison of Wireless Ad-Hoc Sensor Networks." International Foundation for Telemetering, 2004. http://hdl.handle.net/10150/605786.
Full textAbstract:
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, CaliforniaThere are a number of telemetry applications where it would be helpful to have networks of sensors that could autonomously discover their connectivity, and dynamically reconfigure themselves during use. A number of research groups have developed wireless ad-hoc sensor network systems. This paper reviews the state-of-the-art in wireless ad-hoc networks, examining the features, assumptions, limitations and unique attributes of some of the more popular solutions to this problem.
2
Kuppaswamy, Karthik. "Maximizing the System Lifetime in Wireless Sensor Networks using Improved Routing Algorithm." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/theses/677.
Full textAbstract:
In wireless sensor networks, the maximum lifetime routing problem has received increasing attention among researchers. There are several critical features that need to be considered while designing a wireless sensor networks such as cost, network lifetime and Quality of service. Due to the limitation on the energy of sensor nodes, energy efficient routing is a very important issue in sensor networks. Therefore, to prolong the lifetime of the sensor nodes, designing efficient routing protocols is critical. One solution is to formulate the routing problem as a linear programming problem by maximizing the time at which the first node runs out of battery. In this paper, with the notion of maximizing the system lifetime, we implemented a new heuristic and evaluated the performance of it with the existing algorithm called flow augmentation algorithm. Further, our experimental results demonstrate that the proposed algorithm significantly outperform FA algorithm, in terms of system lifetime.
3
Zhang, Fenghui. "Effective algorithms and protocols for wireless networking: a topological approach." Diss., Texas A&M University, 2008. http://hdl.handle.net/1969.1/86012.
Full textAbstract:
Much research has been done on wireless sensor networks. However, most protocols
and algorithms for such networks are based on the ideal model Unit Disk Graph
(UDG) model or do not assume any model. Furthermore, many results assume the
knowledge of location information of the network. In practice, sensor networks often
deviate from the UDG model significantly. It is not uncommon to observe stable long
links that are more than five times longer than unstable short links in real wireless
networks. A more general network model, the quasi unit-disk graph (quasi-UDG)
model, captures much better the characteristics of wireless networks. However, the
understanding of the properties of general quasi-UDGs has been very limited, which
is impeding the design of key network protocols and algorithms.
In this dissertation we study the properties for general wireless sensor networks
and develop new topological/geometrical techniques for wireless sensor networking.
We assume neither the ideal UDG model nor the location information of the nodes.
Instead we work on the more general quasi-UDG model and focus on figuring out
the relationship between the geometrical properties and the topological properties of
wireless sensor networks. Based on such relationships we develop algorithms that can
compute useful substructures (planar subnetworks, boundaries, etc.). We also present direct applications of the properties and substructures we constructed including routing,
data storage, topology discovery, etc.
We prove that wireless networks based on quasi-UDG model exhibit nice properties
like separabilities, existences of constant stretch backbones, etc. We develop
efficient algorithms that can obtain relatively dense planar subnetworks for wireless
sensor networks. We also present efficient routing protocols and balanced data storage
scheme that supports ranged queries.
We present algorithmic results that can also be applied to other fields (e.g., information
management). Based on divide and conquer and improved color coding
technique, we develop algorithms for path, matching and packing problem that significantly
improve previous best algorithms. We prove that it is unlikely for certain
problems in operation science and information management to have any relatively
effective algorithm or approximation algorithm for them.
4
Xie, Liguang. "Modeling and Optimization of Rechargeable Sensor Networks." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/52243.
Full textAbstract:
Over the past fifteen years, advances in Micro-Electro-Mechanical Systems (MEMS) technology have enabled rapid development of wireless sensor networks (WSNs). A WSN consists of a large number of sensor nodes that are typically powered by batteries. Each sensor node collects useful information from its environment, and forwards this data to a base station through wireless communications. Applications of WSNs include environmental monitoring, industrial monitoring, agriculture, smart home monitoring, military surveillance, to name a few.
Due to battery constraint at each sensor node, a fundamental challenge for a WSN is its limited operational lifetime -- the amount of time that the network can remain operational before some or all of the sensor nodes run out of battery. To conserve energy and prolong the lifetime of a WSN, there have been active research efforts across all network layers. Although these efforts help conserve energy usage and prolong network lifetime to some extent, energy and lifetime remain fundamental bottlenecks and are the key factors that hinder the wide-scale deployment of WSNs.
This dissertation addresses the energy problem of a WSN by exploiting a recent breakthrough in wireless energy transfer (WET) technology. This breakthrough WET technology is based on the so-called magnetic resonant coupling (MRC), which allows electric energy to be transferred from a source coil to a receive coil without any plugs or wires. The advantages of MRC are high energy transfer efficiency even under omni-direction, not requiring line-of-sight (LOS), and being robust against environmental conditions.
Inspired by this enabling WET technology, this dissertation focuses on applying MRC to a WSN and on studying how to optimally use this technology to address lifetime problem for a WSN. The goal is to fundamentally remove lifetime bottleneck for a WSN. The main contributions of this dissertation are summarized as follows:
1. Single-node Charging for a Sparse WSN. We first investigate how MRC can be applied to a WSN so as to remove the lifetime performance bottleneck in a WSN, i.e., allowing a WSN to remain operational forever. We consider the scenario of a mobile wireless charging vehicle (WCV) periodically traveling inside the sensor network and charging each sensor node's battery wirelessly. We introduce the concept of renewable energy cycle and offer both necessary and sufficient conditions for a sensor node to maintain its renewable energy cycle. We study an optimization problem, with the objective of maximizing the ratio of the WCV's vacation time over the cycle time. For this problem, we prove that the optimal traveling path for the WCV is the shortest Hamiltonian cycle and uncover a number of important properties. Subsequently, we develop a near-optimal solution by a piecewise linear approximation technique and prove its performance guarantee. This first study shows that network lifetime bottleneck can be fundamentally resolved by WET.
2. Multi-node Charging for a Dense WSN. We next exploit recent advances in MRC that allows multiple sensor nodes to be charged at the same time, and show how MRC with multi-node charging capability can address the scalability problem associated with the single-node charging technology. We consider a WCV that periodically travels inside a WSN and can charge multiple sensor nodes simultaneously. Based on the charging range of the WCV, we propose a cellular structure that partitions the two-dimensional plane into adjacent hexagonal cells. We pursue a formal optimization framework by jointly optimizing the traveling path of the WCV, flow routing among the sensor nodes, and the charging time with each hexagonal cell. By employing discretization and a novel Reformulation-Linearization Technique (RLT), we develop a provably near-optimal solution for any desired level of accuracy. Through numerical results, we demonstrate that our solution can indeed address the scalability problem for WET in a dense WSN.
3. Bundling Mobile Base Station and Wireless Energy Transfer: The Pre-planned Path Case. Our aforementioned work is based on the assumption that the location of base station is fixed and known in the WSN. On the other hand, it has been recognized that a mobile base station (MBS) can offer significant advantages over a fixed one. But employing two separate vehicles, one for WET and one for MBS, could be expensive and hard to manage. So a natural question to ask is: can we bundle WET and MBS on the same vehicle? This is the focus of this study. Here, our goal is to minimize energy consumption of the entire system while ensuring that none of the sensor nodes runs out of energy. To simplify the problem, we assume that the path for the vehicle is given a priori. We develop a mathematical model for this problem. Instead of studying the general problem formulation (called CoP-t), which is time-dependent, we show that it is sufficient to study a special subproblem (called CoP-s), which only involves space-dependent variables. Subsequently, we develop a provable near-optimal solution to CoP-s with the development of several novel techniques including discretizing a continuous path into a finite number of segments and representing each segment with worst-case energy bounds.
4. Bundling Mobile Base Station and Wireless Energy Transfer: The Unconstrained Path Case. Based on our experience for the pre-planned path case, we further study the problem where the traveling path of the WCV (also carrying the MBS) can be unconstrained. That is, we study an optimization problem that jointly optimizes the traveling path, stopping points, charging schedule, and flow routing. For this problem, we propose a two-step solution. First, we study an idealized problem that assumes zero traveling time, and develop a provably near-optimal solution to this idealized problem. In the second step, we show how to develop a practical solution with non-zero traveling time and quantify the performance gap between this solution and the unknown optimal solution to the original problem.
This dissertation offers the first systematic investigation on how WET (in particular, the MRC technology) can be exploited to address lifetime bottleneck of a WSN. It lays the foundation of exploring WET for WSNs and other energy-constrained wireless networks. On the mathematical side, we have developed or applied a number of powerful techniques such as piecewise linear approximation, RLT, time-space transformation, discretization, and logical point representation that may be applicable to address a broad class of optimization problems in wireless networks. We expect that this dissertation will open up new research directions on many interesting networking problems that can take advantage of the WET technology.Ph. D.
5
Yagli, Mehmet. "The Feasibility, Reliable Communication And Networking Aspects Of Passive Wireless Sensor Networks." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607729/index.pdf.
Full textAbstract:
The primary challenge in wireless sensor network (WSN) deployment is the limited network lifetime due to the finite-capacity batteries. In accordance with this challenge, the vast majority of research efforts thus far have focused on the development of energy-efficient communication and computing mechanisms for WSNs. In this thesis, a fundamentally different approach and hence completely new WSN paradigm, i.e., the Passive Wireless Sensor Network (PWSN), is introduced. The objective of PWSN is to eliminate the limitation on the system lifetime of the WSNs. In PWSN, power is externally supplied to the sensor network node via an external RF source. Hence, the lifetime of the system is no longer determined by the lifetime of the batteries. An alternative communication scheme, modulated backscattering, is also discussed to be utilized in PWSN. The feasibility of the proposed system is investigated along with the open research challenges for reliable communication and networking in PWSN. Additionally, a new medium access schemee for PWSN, Ultra-Wideband PWSN Medium Access Control (UWB PWSN MAC), is presented.
6
Ghataoura, D. S. "Networking and application interface technology for wireless sensor network surveillance and monitoring." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1348374/.
Full textAbstract:
Distributed unattended ground sensor (UGS) networks are commonly deployed to support wide area battlefield surveillance and monitoring missions. The information they generate has proven to be valuable in providing a necessary tactical information advantage for command and control, intelligence and reconnaissance field planning. Until recently, however, there has been greater emphasis within the defence research community for UGS networks to fulfil their mission objectives successfully, with minimal user interaction. For a distributed UGS scenario, this implies a network centric capability, where deployed UGS networks can self-manage their behaviour in response to dynamic environmental changes. In this thesis, we consider both the application interface and networking technologies required to achieve a network centric capability, within a distributed UGS surveillance setting. Three main areas of work are addressed towards achieving this. The first area of work focuses on a capability to support autonomous UGS network management for distributed surveillance operations. The network management aspect is framed in terms of how distributed sensors can collaborate to achieve their common mission objectives and at the same time, conserve their limited network resources. A situation awareness methodology is used, in order to enable sensors which have similar understanding towards a common objective to be utilised, for collaboration and to allow sensor resources to be managed as a direct relationship according to, the dynamics of a monitored threat. The second area of work focuses on the use of geographic routing to support distributed surveillance operations. Here we envisage the joint operation of unmanned air vehicles and UGS networks, working together to verify airborne threat observations. Aerial observations made in this way are typically restricted to a specific identified geographic area. Information queries sent to inquire about these observations can also be routed and restricted to using this geographic information. In this section, we present our bio-inspired geographic routing strategy, with an integrated topology control function to facilitate this. The third area of work focuses on channel aware packet forwarding. Distributed UGS networks typically operate in wireless environments, which can be unreliable for packet forwarding purposes. In this section, we develop a capability for UGS nodes to decide which packet forwarding links are reliable, in order to reduce packet transmission failures and improve overall distributed networking performance.
7
Modieginyane, Kgotlaetsile Mathews. "Flexible network management in software defined wireless sensor networks for monitoring application systems." Thesis, University of Pretoria, 2018. http://hdl.handle.net/2263/66016.
Full textAbstract:
Wireless Sensor Networks (WSNs) are the commonly applied information technologies of modern networking and computing platforms for application-specific systems. Today’s network computing applications are faced with high demand of reliable and powerful network functionalities. Hence, efficient network performance is central to the entire ecosystem, more especially where human life is a concern. However, effective management of WSNs remains a challenge due to problems supplemental to them. As a result, WSNs application systems such as in monitored environments, surveillance, aeronautics, medicine, processing and control, tend to suffer in terms of capacity to support compute intensive services due to limitations experienced on them. A recent technology shift proposes Software Defined Networking (SDN) for improving computing networks as well as enhancing network resource management, especially for life guarding systems. As an optimization strategy, a software-oriented approach for WSNs, known as Software Defined Wireless Sensor Network (SDWSN) is implemented to evolve, enhance and provide computing capacity to these resource constrained technologies.
Software developmental strategies are applied with the focus to ensure efficient network management, introduce network flexibility and advance network innovation towards the maximum operation potential for WSNs application systems. The need to develop WSNs application systems which are powerful and scalable has grown tremendously due to their simplicity in implementation and application. Their nature of design serves as a potential direction for the much anticipated and resource abundant IoT networks. Information systems such as data analytics, shared computing resources, control systems, big data support, visualizations, system audits, artificial intelligence (AI), etc. are a necessity to everyday life of consumers. Such systems can greatly benefit from the SDN programmability strategy, in terms of improving how data is mined, analysed and committed to other parts of the system for greater functionality. This work proposes and implements SDN strategies for enhancing WSNs application systems especially for life critical systems. It also highlights implementation considerations for designing powerful WSNs application systems by focusing on system critical aspects that should not be disregarded when planning to improve core network functionalities.
Due to their inherent challenges, WSN application systems lack robustness, reliability and scalability to support high computing demands. Anticipated systems must have greater capabilities to ubiquitously support many applications with flexible resources that can be easily accessed. To achieve this, such systems must incorporate powerful strategies for efficient data aggregation, query computations, communication and information presentation. The notion of applying machine learning methods to WSN systems is fairly new, though carries the potential to enhance WSN application technologies. This technological direction seeks to bring intelligent functionalities to WSN systems given the characteristics of wireless sensor nodes in terms of cooperative data transmission. With these technological aspects, a technical study is therefore conducted with a focus on WSN application systems as to how SDN strategies coupled with machine learning methods, can contribute with viable solutions on monitoring application systems to support and provide various applications and services with greater performance. To realize this, this work further proposes and implements machine learning (ML) methods coupled with SDN strategies to; enhance sensor data aggregation, introduce network flexibility, improve resource management, query processing and sensor information presentation. Hence, this work directly contributes to SDWSN strategies for monitoring application systems.Thesis (PhD)--University of Pretoria, 2018.
National Research Foundation (NRF)
Telkom Centre of Excellence
Electrical, Electronic and Computer Engineering
PhD
Unrestricted
8
Lydon, Sean Michael. "General Direction Routing Protocol." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/97.
Full textAbstract:
The General Direction Routing Protocol (GDRP) is a Wireless Sensor Network (WSN)
multi-path routing protocol which abstracts localization information (commonly GPS
coordinates) into relative direction information in order to perform routing decisions. By
generating relative direction information GDRP is able to operate with fewer precision
requirements than other protocols. This abstraction also allows the integration of other emerging
hardware-based localization techniques, for example, Beamforming Sensor Arrays.
GDRP does not specifically address the next hop a packet should take, but instead specifies a
direction it should travel. This direction abstraction allows for multiple paths to be taken through
the network thus enhancing network robustness to node mobility and failures. This indirect
addressing scheme also provides a solution to sensor node unique identification.
GDRP is simulated in a custom simulator written in Java. This simulator supports interfaces
for multiple protocols for layers 1, 2, 3, and 7 of the OSI model. For performance comparisons,
GDRP is compared against multiple WSN routing protocols. GDRP operates with a significantly
lower setup cost in terms of bytes transmitted and a lower setup latency for networks of varying
sizes. It also demonstrates an exponentially lower routing cost when compared to another multi-
path routing protocol due to a more efficient packet propagation in the network.
9
Kuntz, Romain. "Medium Access Control Facing the Dynamics of Wireless Sensor Networks." Phd thesis, Université de Strasbourg, 2010. http://tel.archives-ouvertes.fr/tel-00521389.
Full textAbstract:
Un réseau de capteurs sans fil (Wireless Sensor Network, WSN) consiste en une distribution spatiale d'équipements embarqués autonomes, qui coopèrent de manière à surveiller l'environnement de manière non-intrusive. Les données collectées par chaque capteur (tels que la température, des vibrations, des sons, des mouvements etc.) sont remontées de proche en proche vers un puits de collecte en utilisant des technologies de communication sans fil. Voilà une décennie que les contraintes inhérentes à ces réseaux attirent l'attention de la communauté scientifique. Ainsi, de nombreuses améliorations à différents niveaux de la pile de communication ont été proposées afin de relever les défis en termes d'économie d'énergie, de capacité de calcul et de contrainte mémoire imposés par l'utilisation d'équipements embarqués. Plusieurs déploiements couronnés de succès démontrent l'intérêt grandissant pour cette technologie. Les récentes avancées en termes d'intégration d'équipements et de protocoles de communication ont permis d'élaborer de nouveaux scénarios plus complexes. Ils mettent en scène des réseaux denses et dynamiques par l'utilisation de capteurs mobiles ou de différentes méthodes de collection de données. Par exemple, l'intérêt de la mobilité dans les WSN est multiple dans la mesure où les capteurs mobiles peuvent notamment permettre d'étendre la couverture d'un réseau, d'améliorer ses performances de routage ou sa connexité globale. Toutefois, ces scénarios apportent de nouveaux défis dans la conception de protocoles de communication. Ces travaux de thèse s'intéressent donc à la problématique de la dynamique des WSN, et plus particulièrement à ce que cela implique au niveau du contrôle de l'accès au médium (Medium Access Control, MAC). Nous avons tout d'abord étudié l'impact de la mobilité et défini deux nouvelles méthodes d'accès au médium (Machiavel et X-Machiavel) qui permettent d'améliorer les conditions d'accès au canal pour les capteurs mobiles dans les réseaux denses. Notre deuxième contribution est un algorithme d'auto-adaptation destiné aux protocoles par échantillonnage. Il vise à minimiser la consommation énergétique globale dans les réseaux caractérisés par des modèles de trafic antagonistes, en obtenant une configuration optimale sur chaque capteur. Ce mécanisme est particulièrement efficace en énergie pendant les transmissions par rafales qui peuvent survenir dans de tels réseaux dynamiques.
10
Sun, Zhi. "Reliable and efficient communication in wireless underground sensor networks." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41150.
Full textAbstract:
Wireless Underground Sensor Networks (WUSNs) are the networks of wireless sensors that operate below the ground surface. These sensors are either buried completely in soil medium, or placed within a bounded open underground space, such as underground mines and tunnels. WUSNs enable a wide variety of novel applications, including intelligent irrigation, underground structure monitoring, and border patrol and intruder detection.
This thesis is concerned with establishing reliable and efficient communications in the network of wireless sensor nodes that are deployed in either soil medium or underground mines and tunnels. In particular, to realize WUSNs in soil medium, two types of signal propagation techniques including Electromagnetic (EM) waves and Magnetic Induction (MI) are explored. For EM wave-based WUSNs, the heterogeneous network architecture and dynamic connectivity are investigated based on a comprehensive channel model in soil medium. Then a spatio-temporal correlation-based data collection schemes is developed to reduce the sensor density while keeping high monitoring accuracy. For MI-based WUSNs, the MI channel is first analytically characterized. Then based on the MI channel model, the MI waveguide technique is developed in order to enlarge the underground transmission range. Finally, the optimal deployment algorithms for MI waveguides in WUSNs are analyzed to construct the WUSNs with high reliability and low costs. To realize WUSNs in underground mines and tunnels, a mode-based analytical channel model is first proposed to accurately characterize the signal propagation in both empty and obstructed mines and tunnels. Then the Multiple-Input and Multiple-Output (MIMO) system and cooperative communication system are optimized to establish reliable and efficient communications in underground mines and tunnels.
11
Zen, Kartinah. "MAC protocol design considerations for efficient mobility in wireless sensor networks." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2010. https://ro.ecu.edu.au/theses/1869.
Full textAbstract:
Research in wireless sensor networks (WSNs) has evolved with advancements in low power devices technology during the last decade. The driving applications in WSNs are habitat and environmental monitoring. However, sensors can also be applied in smart homes, health monitoring, vehicles tracking, military, and fire detection. Since batterypowered sensors are intended to be left for months or years without human intervention, computational algorithms and communication protocols for WSNs focus more on energy conservation rather than throughput and delay as in other wireless networks.
Recently, WSN research has grown from static to mobile sensor networks (MSNs). However, there are some weaknesses in the standard medium access control (MAC) protocol for WSNs when applied to mobile sensor networks. Mobile nodes in MSN consume more energy due to more overhead messages, experiencing longer disconnectivity periods each time the mobile nodes enter a new coverage range, having difficulty maintaining synchronisation with neighbours and spending more time in connectivity set up rather than sensing and monitoring.
The aim of this thesis is to overcome the limitations in the standard WSN MAC protocol in supporting mobile nodes so that reasonable throughput and energy conservation can be achieved. The enhancements in MAC protocol that we implement for MSN are achieved using four different mechanisms. The first mechanism aims to minimise the waiting period between the instance when a mobile node moves out of the coverage range of the assigned coordinator, until a new coordinator is assigned to it and communication is established with the new coordinator. We propose a technique for mobile nodes to estimate their positions based on available or predicted link quality indicator (LQI) values. Simulation results show that this mechanism successfully reduces energy consumption and shortens disconnectivity periods.
The second mechanism resolves the issue of choosing the coordinator which possibly may offer the longest connectivity period to a mobile node which has just moved out of the coverage range of the last assigned coordinator. In this design, different ranges of LQI value within a coordinator’s coverage area are exploited to estimate the distance between the coordinator and the mobile node and to also predict the mobile node’s future direction. This mechanism increases the connectivity period of mobile nodes. Energy consumption is also reduced because a mobile node, when losing connectivity, deals with fewer overhead messages by optimising the choice of the new coordinator based on an estimate of its movement direction.
The third mechanism proposed in this thesis shortens disconnectivity periods for the case of high speed nodes when beacon frame intervals are also long, by encouraging the mobile nodes to switch coordinator before these nodes lose their connectivity with their current coordinator. This mechanism applies an adaptive switching time for a mobile node, based on beacon frame interval and the speed of the mobile node. Simulation results show that this mechanism successfully overcomes the delay in the case of long beacon frame interval, and can cope with higher speed of mobile nodes compared to the standard MAC protocol.
The last proposed mechanism in this thesis aims to avoid early energy exhaustion of a coordinator due to excessive number of nodes attached to it. This mechanism introduces load balancing among coordinators in a ZigBee tree topology. Load balancing can distribute energy consumption more uniformly across the network and reduce delays in data transmission. Overall, the work presented in this thesis improve the support for mobility of sensor nodes and achieve longer connectivity periods, shorter disconnectivity intervals, lower energy consumption, better capability to deal with higher speeds, and improved throughput and better utilisation of network capacity compared to the standard WSN MAC protocol.
12
Clark, Shyla. "Remote Monitoring of Cherry Wetness Using a Leaf Wetness Sensor and a Wireless Sensor Network." ScholarWorks@UNO, 2018. https://scholarworks.uno.edu/td/2448.
Full textAbstract:
To get the best prices, sweet cherry growers must supply blemish-free fruit. Unfortunately, mature cherries have a fragile composition, rendering them susceptible to damage from heat, wind, birds, and rain. Rain is particularly devastating, because cherries split when they absorb too much water. Since rainstorms are common in the otherwise arid regions where most cherries are grown, growers must have a system for quickly deploying rain removal methods. The current industry solution relies on human observation and implementation, which is error-prone and costly. This project proposes an automated cherry wetness system using a Decagon Devices leaf wetness sensor (LWS) and a wireless sensor network (WSN). The research consists of analyzing industry and literature for uses of WSNs and LWSs in orchards and testing a LWS in a prototype WSN. The system will be evaluated for its potential to provide a precision-agriculture solution to the problem of remote cherry wetness detection.
13
Segura, Gustavo Alonso Nuñez. "Energy consumption prediction in software-defined wirelwss sensor networks." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3141/tde-04052018-113551/.
Full textAbstract:
Energy conservation is a main concern in Wireless Sensor Networks (WSN). To reduce energy consumption it is important to know how it is spent and how much is available during the node and network operation. Several previous works have proposed energy consumption models focused on the communication module, while neglecting the processing and sensing activities. Other works presented more complex and complete models, but lacked experiments to demonstrate their accuracy in real deployments. The main objective of this work is to design and to evaluate an accurate energy consumption model for WSN, which considers the sensing, processing, and communication modules usage. This model was used to implement two energy consumption prediction mechanism. One mechanism is based in Markov chains and the other one is based in time series analysis. The metrics to evaluate the model and prediction mechanisms performance were: energy consumption estimation accuracy, energy consumption prediction accuracy, and node\'s communication and processing resources usage. The energy consumption prediction mechanisms performance was compared using two implementation schemes: running the prediction algorithm in the sensor node and running the prediction algorithm in a Software-Defined Networking controller. The implementation was conducted using IT-SDN, a Software-Defined Wireless Sensor Network framework. For the evaluation, simulation and emulation used COOJA, while testbed experiments used TelosB devices. Results showed that considering the sensing, processing, and communication energy consumption into the model, it is possible to obtain an accurate energy consumption estimation for Wireless Sensor Networks. Also, the use of a Software-Defined Networking controller for processing complex prediction algorithms can improve the prediction accuracy.A conservação da energia é uma das principais preocupações nas Redes de Sensores Sem Fio (WSN, do inglês Wireless Sensor Networks). Para reduzir o consumo de energia, é importante saber como a energia é gasta e quanta energia há disponível durante o funcionamento da rede. Diversos trabalhos anteriores propuseram modelos de consumo de energia focados no módulo de comunicação, ignorando o consumo por tarefas de processamento e sensoriamento. Outros trabalhos apresentam modelos mais completos e complexos, mas carecem de experimentos que demonstrem a exatidão em dispositivos reais. O objetivo principal deste trabalho é projetar e avaliar um modelo de consumo de energia para WSN que considere o consumo por sensoriamento, processamento e comunicação. Este modelo foi utilizado para implementar dois mecanismos de previsão de consumo de energia, um deles baseado em cadeias de Markov e o outro baseado em séries temporais. As métricas para avaliar o desempenho do modelo e dos mecanismos de previsão de consumo de energia foram: exatidão da estimativa de consumo de energia, exatidão da previsão de consumo de energia e uso dos recursos de comunicação e processamento do nó. O desempenho dos mecanismos de previsão de consumo de energia foram comparados utilizando dois esquemas de implementação: rodando o algoritmo de previsão no nó sensor e rodando o algoritmo de previsão em um controlador de rede definida por software. A implementação foi conduzida utilizando IT-SDN, um arcabouço de desenvolvimento de redes de sensores sem fio definidas por software. A avaliação foi feita com simulações e emulações utilizando o simulador COOJA e ensaios com dispositivos reais utilizando o TelosB. Os resultados mostraram que considerando o consumo de energia por sensoriamento, processamento e communicação, é possivel fazer uma estimativa de consumo de energia em redes de sensores sem fio com uma boa exatidão. Ainda, o uso de um controlador de rede definida por software para processamento de algoritmos de previsão complexos pode aumentar a exatidão da previsão.
14
Baccelli, Emmanuel. "IP-Disruptive Wireless Networking: Integration in the Internet." Habilitation à diriger des recherches, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00770791.
Full textAbstract:
The super collision between the Internet phenomenon and the wireless communication revolution gives birth to a wealth of novel research problems, design challenges and standardization activities. Within this domain, spontaneous wireless IP networking are probably the most extreme example of new ''particles'' born from the collision. Indeed, these particles defy the laws of the Internet in many ways. The absorption of such peculiar particles in the global IP network has already started thanks to pioneering algorithmic and protocol work -- for instance OLSR -- and through the deployment of wireless mesh networks around the world, such as urban community wireless networks. With the recent revolutions in North Africa, and movements such as Occupy Wall Street, the prospect of spontaneous wireless IP networking has become even more attractive on social and political grounds. Dedicated conferences have recently been organized, and as a result, ambitious, multi-million dollar initiatives have been launched (e.g. the US Government-funded project Commotion Wireless, or the EU-funded initiative CONFINE). However, spontaneous IP wireless networks are not yet widely deployed because pioneer work such as OLSR is vastly insufficient to fully bridge the gap between the Internet and these new networks. This thesis presents work that analyzes this gap and proposes some solutions as to how to bridge it. The focus is put on three domains: a first part presents work in the domain of wireless mesh and ad hoc networks. A second part presents work on sensor networks and in the Internet of Things. And the last part presents work in the domain of delay tolerant networking and vehicular networks.
15
Jin, Xinyu. "Trajectory Privacy Preservation in Mobile Wireless Sensor Networks." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/983.
Full textAbstract:
In recent years, there has been an enormous growth of location-aware devices, such as GPS embedded cell phones, mobile sensors and radio-frequency identification tags. The age of combining sensing, processing and communication in one device, gives rise to a vast number of applications leading to endless possibilities and a realization of mobile Wireless Sensor Network (mWSN) applications. As computing, sensing and communication become more ubiquitous, trajectory privacy becomes a critical piece of information and an important factor for commercial success. While on the move, sensor nodes continuously transmit data streams of sensed values and spatiotemporal information, known as ``trajectory information". If adversaries can intercept this information, they can monitor the trajectory path and capture the location of the source node.
This research stems from the recognition that the wide applicability of mWSNs will remain elusive unless a trajectory privacy preservation mechanism is developed. The outcome seeks to lay a firm foundation in the field of trajectory privacy preservation in mWSNs against external and internal trajectory privacy attacks. First, to prevent external attacks, we particularly investigated a context-based trajectory privacy-aware routing protocol to prevent the eavesdropping attack. Traditional shortest-path oriented routing algorithms give adversaries the possibility to locate the target node in a certain area. We designed the novel privacy-aware routing phase and utilized the trajectory dissimilarity between mobile nodes to mislead adversaries about the location where the message started its journey. Second, to detect internal attacks, we developed a software-based attestation solution to detect compromised nodes. We created the dynamic attestation node chain among neighboring nodes to examine the memory checksum of suspicious nodes. The computation time for memory traversal had been improved compared to the previous work. Finally, we revisited the trust issue in trajectory privacy preservation mechanism designs. We used Bayesian game theory to model and analyze cooperative, selfish and malicious nodes' behaviors in trajectory privacy preservation activities.
16
Pignaton, de Freitas Edison. "Cooperative Context-Aware Setup and Performance of Surveillance Missions Using Static and Mobile Wireless Sensor Networks." Doctoral thesis, Högskolan i Halmstad, Centrum för forskning om inbyggda system (CERES), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-16476.
Full textAbstract:
Surveillance systems are usually employed to monitor wide areas in which their usersaim to detect and/or observe events or phenomena of their interest. The use ofwireless sensor networks in such systems is of particular interest as these networks can provide a relative low cost and robust solution to cover large areas. Emerging applications in this context are proposing the use of wireless sensor networks composed of both static and mobile sensor nodes. Motivation for this trend is toreduce deployment and operating costs, besides providing enhanced functionalities.The usage of both static and mobile sensor nodes can reduce the overall systemcosts, by making low-cost simple static sensors cooperate with more expensive andpowerful mobile ones. Mobile wireless sensor networks are also desired in somespecific scenarios in which mobility of sensor nodes is required, or there is a specificrestriction to the usage of static sensors, such as secrecy. Despite the motivation,systems that use different combinations of static and mobile sensor nodes are appearing and with them, challenges in their interoperation. This is specially the case for surveillance systems.This work focuses on the proposal of solutions for wireless sensor networks including static and mobile sensor nodes specifically regarding cooperative andcontext aware mission setup and performance. Orthogonally to the setup and performance problems and related cooperative and context aware solutions, the goalof this work is to keep the communication costs as low as possible in the executionof the proposed solutions. This concern comes from the fact that communication increases energy consumption, which is a particular issue for energy constrained sensor nodes often used in wireless sensor networks, especially if battery supplied. Inthe case of the mobile nodes, this energy constraint may not be valid, since their motion might need much more energy. For this type of node the problem incommunicating is related to the links’ instabilities and short time windows availableto receive and transmit data. Therefore, it is better to communicate as little as possible. For the interaction among static and mobile sensor nodes, all thesecommunication constraints have to be considered.For the interaction among static sensor nodes, the problems of dissemination and allocation of sensing missions are studied and a solution that explores local information is proposed and evaluated. This solution uses mobile software agentsthat have capabilities to take autonomous decisions about the mission dissemination and allocation using local context information so that the mission’s requirementscan be fulfilled. For mobile wireless sensor networks, the problem studied is how to perform the handover of missions among the nodes according to their movements.This problem assumes that each mission has to be done in a given area of interest. In addition, the nodes are assumed to move according to different movement patterns,passing through these areas. It is also assumed that they have no commitment in staying or moving to a specific area due to the mission that they are carrying. To handle this problem, a mobile agent approach is proposed in which the agents implement the sensing missions’ migration from node to node using geographical context information to decide about their migrations. For the networks combining static and mobile sensor nodes, the cooperation among them is approached by abiologically-inspired mechanism to deliver data from the static to the mobile nodes.The mechanism explores an analogy based on the behaviour of ants building and following trails to provide data delivery, inspired by the ant colony algorithm. It is used to request the displacement of mobile sensors to a given location according tothe need of more sophisticated sensing equipment/devices that they can provide, so that a mission can be accomplished.The proposed solutions are flexible, being able to be applied to different application domains, and less complex than many existing approaches. The simplicity of the solutions neither demands great computational efforts nor large amounts of memory space for data storage. Obtained experimental results provide evidence of the scalability of these proposed solutions, for example by evaluatingtheir cost in terms of communication, among other metrics of interest for eachsolution. These results are compared to those achieved by reference solutions (optimum and flooding-based), providing indications of the proposed solutions’ efficiency. These results are considered close to the optimum one and significantly better than the ones achieved by flooding-based solutions.
17
Erdelj, Milan. "Mobile wireless sensor network architecture : applications to mobile sensor deployment." Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2013. http://tel.archives-ouvertes.fr/tel-00914987.
Full textAbstract:
Les progrès de la robotique mobile nous permettent aujourd'hui d'ajouter la notion de mobilité dans plusieurs classes de réseaux de capteurs sans fil. Le déploiement de capteurs mobiles est possible et utile dans de nombreuses applications, comme la surveillance de l'environnement, les applications dans l'industrie, dans la santé et le domaine militaire. Le terme robot mobile peut représenter n'importe quel type de robot avec la capacité de modifier sa position. Cette notion inclut une vaste gamme de robots industriels utilisés dans les lignes de production. Dans le contexte spécifique de cette thèse, l'attention se focalise uniquement sur les robots mobiles et plus particulièrement les véhicules autonomes dont les mouvements ne sont pas limités par leur taille physique. Ainsi, un robot ou un groupe de robots mobiles peuvent être utilisés pour explorer des environnements inconnus et effectuer une variété de fonctions. La mobilité du robot dans le contexte des réseaux de capteurs, nous permet de résoudre les problèmes qui ne pourraient pas être résolues dans un cas statique. Les robots mobiles permettent d'augmenter la robustesse du réseau en remplaçant des nœuds de capteurs et de s'adapter aux environnements inconnus ou dynamiques. Deux thèmes sont abordées dans cette thèse : la conception d'un intergiciels pour les réseaux de robots mobiles et un ensemble d'approches pour le déploiement de robots mobiles dans le cadre de réseaux de capteurs sans fil. L'intergiciel proposé et décrit dans cette thèse permet à l'utilisateur de facilement mettre en œuvre différents types d'algorithmes de déploiement pour les robots mobiles. Il permet de déployer une application sur la station de base centrale qui permet à un utilisateur de rassembler toutes les informations captées par la flotte de robots. L'application de la station de base permet à un utilisateur d'envoyer des commandes à un groupe ou à un robot, introduisant ainsi la commande manuelle en option dans le réseau robotique. L'intergiciel présenté dans ce travail est dédié à être utilisé avec des robots mobiles Wifibot. Il permet réaliser plusieurs tâches. Tout d'abord, il interagit avec le microgiciel du robot pour piloter les moteurs des roues et recueille les informations concernant la sortie du capteur et de l'état de la batterie. Deuxièmement, il gère la communication avec d'autres robots et les stations de base du réseau. Troisièmement, il traite les informations sur l'environnement et les messages reçus des voisins dans le réseau. Enfin, il réagit et il s'adapte de manière rapide et fiable pour aux événements de l'environnement. Dans la deuxième partie de la thèse, trois problèmes sont présentés et analysés : le problème de l'amélioration de la qualité de service avec l'utilisation des réseaux robotiques mobiles, la couverture du point d'intérêt avec des robots mobiles et la découverte de points d'intérêt et leur couverture avec l'utilisation des robots mobiles. Le premier problème est résolu avec l'utilisation de l'algorithme de déploiement qui améliore les performances de la transmission multimédia. Cet algorithme utilise une méthode intrusive pour réunir les métriques de qualité de service. Ensuite, l'attention est focalisé sur l'application des réseaux de capteurs sans fil est la surveillance de l'environnement. Au lieu de surveiller toute la région, couvrir seulement un ensemble de points d'intérêt spécifiques accroît les performances du réseau et réduit le coût de déploiement. Nous faison l'hypothèse que la station de base fixe est placé à l'intérieur du domaine d'intérêt, tandis que les robots mobiles disponibles couvrent le point d'intérêt et relayent l'information vers la station de base. L'approche pour résoudre le dernier problème est basée sur le mouvement continu et à vitesse variable de capteurs mobiles, qui suivent des trajectoires circulaires concentriques afin d'explorer et de couvrir le domaine d'intérêt. En se déplaçant constamment, les capteurs exécutent la tâche de découverte de l'environnement et, en ajustant la vitesse de déplacement, ils répondent aux contraintes de la couverture et la connectivité avec la station de base. L'algorithme installé sur tous les capteurs mobiles est distribué et introduit une nouvelle technique de calcul de la vitesse en fonction des informations disponibles à partir des capteurs dans le voisinage à un-saut. Ces algorithmes de déploiement de robots mobiles ont prouvé leur faisabilité à travers de nom- breuses simulations ainsi que dans la mise en pratique en s'appuyant sur l'intergiciel proposé.
18
Letswamotse, Babedi Betty. "Software defined networking based resource management and quality of service support in wireless sensor network applications." Thesis, University of Pretoria, 2018. http://hdl.handle.net/2263/67319.
Full textAbstract:
To achieve greater performance in computing networks, a setup of critical computing aspects that ensures efficient network operation, needs to be implemented. One of these computing aspects is, Quality of Service (QoS). Its main functionality is to manage traffic queues by means of prioritizing sensitive network traffic. QoS capable networking allows efficient control of traffic especially for network critical data. However, to achieve this in Wireless Sensor Networks (WSN) is a serious challenge, since these technologies have a lot of computing limitations. It is even difficult to manage networking resources with ease in these types of technologies, due to their communication, processing and memory limitations. Even though this is the case with WSNs, they have been largely used in monitoring/detection systems, and by this proving their application importance.
Realizing efficient network control requires intelligent methods of network management, especially for sensitive network data. Different network types implement diverse methods
to control and administer network traffic as well as effectively manage network resources. As with WSNs, communication traffic and network resource control are mostly performed depending on independently employed mechanisms to deal with networking events occurring on different levels. It is therefore challenging to realize efficient network performance with guaranteed QoS in WSNs, given their computing limitations. Software defined networking (SDN) is advocated as a potential paradigm to improve and evolve WSNs in terms of capacity and application. A means to apply SDN strategies to these compute-limited WSNs, formulates software defined wireless sensor networks (SDWSN).
In this work, a resource-aware OpenFlow-based Active Network Management (OF-ANM) QoS scheme that uses SDN strategies is proposed and implemented to apply QoS requirements for managing traffic congestion in WSNs. This scheme uses SDN programmability strategies to apply network QoS requirements and perform traffic load balancing to ensure congestion control in SDWSN. Our experimental results show that the developed scheme is able to provide congestion avoidance within the network. It also allows opportunities to implement flexible QoS requirements based on the system’s traffic state.
Moreover, a QoS Path Selection and Resource-associating (Q-PSR) scheme for adaptive load balancing and intelligent resource control for optimal network performance is proposed and implemented. Our experimental results indicate better performance in terms of computation with load balancing and efficient resource alignment for different networking tasks when compared with other competing schemes.Thesis (PhD)--University of Pretoria, 2019.
National Research Foundation
University of Pretoria
Electrical, Electronic and Computer Engineering
PhD
Unrestricted
19
Mehta, Anil. "MAC AND APPLICATION LAYER PROTOCOLS FOR HIGH PERFORMANCE NETWORKING." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/dissertations/396.
Full textAbstract:
High-performance networking (HPN) is of significance today in order to enable next-generation applications using wired and wireless networks. Some of the examples of HPN include low-latency industrial sensing, monitoring and automation using Wireless Sensor Networks (WSNs). HPN however requires protocol optimization at many layers of the open system interface (OSI) network model in order to meet the stringent performance constraints of the given applications. Furthermore, these protocols need to be impervious to denial of service (DoS) and distributed DoS (DDoS) attacks. Some of the key performance aspects of HPN are low point-to-point and end-to-end latency, high reliability of transmitted frames and performance predictability under various network load situations. This work focuses on two discrete issues in designing protocols for HPN applications. The first research issue looks at the Medium Access Control (MAC) layer of the OSI network model for designing of MAC protocols that provide low-latency and high reliability for point-to-point communication under a WSN. Existing standards in this area are governed by IEEE 802.15.4 specification which defines protocols for MAC and PHY layers for short-range, low bit-rate, and low-cost wireless networks. However, the IEEE 802.15.4 specification is inefficient in terms of latency and reliability performance and, as a result, is unable to meet the stringent operational requirements as defined by counterpart wired sensor networks. Work presented under current research issue describes new MAC protocols that are able to show low-latency transmission performance under strict timing constants for power limited WSNs. This enhancement of the MAC protocols is named extended GTS (XGTS) contained under extended CFP (ECFP) and is published under the IEEE's 802.15.4e standard. The second research issue focuses on the application layer of the OSI network model to design protocols that enhance the robustness of the text based protocols to various traffic inputs. The purpose of this is to increase the reliability of the given text based application layer protocol under a varied load. Session Initiation Protocol (SIP) is used as a case study and the work aims to build algorithms that ensure that SIP can continue to function under specific traffic conditions, which would otherwise deem the protocol useless due to DoS and DDoS attacks. Proposed algorithms investigate techniques that enhance the robustness of the SIP against parsing attacks without performing a deep parse of the protocol data unit (PDU). The desired effect of this is to reduce the time spent in parsing the SIP messages at a SIP router and as a result increase the number of SIP messages processed per unit time at a SIP router.
20
Freitas, Edison Pignaton de. "Cooperative context-aware setup and performance of surveillance missions using static and mobile wireless sensor networks." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/39120.
Full textAbstract:
Sistemas de vigilância são geralmente empregados no monitoramento de áreas de grandes dimensões nas quais seus usuários visam detectar ou observar fenômenos de seu interesse. O uso de redes de sensores sem fio nesses sistemas apresenta especial interesse, uma vez que essas redes podem apresentar soluções de baixo custo e robustas para cobrir áreas extensas. Neste contexto, novas aplicações têm surgido propondo o uso de redes de sensores sem fio compostas por nós sensores estáticos e móveis. Uma das motivações para esta tendência é a redução do custo de implantação e operação do sistema, além da possibilidade de proporcionar incremento em suas funcionalidades. O foco desta tese se concentra na proposta de soluções para redes de sensores sem fio com uso cooperativo de sensores estáticos e móveis, com particular atenção a sensibilidade ao contexto na configuração e execução de missões de sensoriamento. O objetivo é manter um baixo custo de comunicação associado às soluções propostas. Esta preocupação se dá pelo fato da comunicação aumentar o consumo de energia em redes de sensores, o que é um problema importante para nós sensores com limitada fonte de energia, i.e. baterias. No caso de nós sensores móveis, esta limitação pode não ser relevante, uma vez que seu movimento deve consumir uma quantidade muito mais expressiva de energia do que a comunicação. Neste caso, o problema se relaciona à estabilidade dos enlaces, bem como ao curto intervalo de tempo disponível para transmitir e receber dados. Logo, o melhor é comunicar o menos possível. Com relação à interação entre nós sensores estáticos, os problemas de disseminação e alocação de missões de sensoriamento são estudados e uma solução que explora o uso de informações locais é proposta e avaliada. Esta solução emprega agentes de software móveis que têm a capacidade de tomar decisões autônomas através do uso de informações de contexto local. Para redes de sensores móveis, o problema estudado se refere a como transferir missões entre os nós sensores de acordo com seu movimento e localização em relação aos locais onde as missões devem ser executadas. Para tratar este problema, uma abordagem baseada em agentes móveis é proposta, na qual os agentes implementam a migração das missões de sensoriamento usando informações de contexto geográfico para decidir a respeito de suas migrações. Para redes de sensores com sensores estáticos e móveis, a cooperação entre eles é abordada através de um mecanismo com inspiração biológica para realizar a realizar a entrega de dados emitidos pelos sensores estáticos aos sensores móveis. Para isto, explora-se uma analogia baseada no comportamento de formigas na construção e seguimento de trilhas. As soluções propostas são flexíveis, sendo aplicáveis a diferentes domínios de aplicação. Resultados experimentais evidenciam sua escalabilidade, avaliando, por exemplo, seu custo em termos de comunicação, além de outras métricas de interesse para cada uma das soluções. Estes resultados são comparados aos atingidos por soluções de referência (solução ótima teórica e baseada em inundação), indicando sua eficiência. Estes resultados são próximos do ótimo teórico e significativamente melhores que aqueles atingidos por soluções baseadas em técnicas de inundação.Surveillance systems are usually employed to monitor wide areas in which their users are interested in detecting and/or observing events or phenomena of their interest. The use of wireless sensor networks in such systems is of particular interest as these networks can provide a relative low cost and robust solution to cover large areas. Emerging applications in this context are proposing the use of wireless sensor networks composed of both static and mobile sensor nodes. Motivation for this trend is to reduce deployment and operating costs, besides providing enhanced functionalities. This work focuses on the proposal of solutions for wireless sensor networks including static and mobile sensor nodes specifically regarding cooperative and context aware mission setup and performance. The goal is to keep the communication costs as low as possible in the execution of the proposed solutions. This concern comes from the fact that communication increases energy consumption, which is a particular issue for energy constrained sensor nodes often used in wireless sensor networks, especially if battery supplied. In the case of the mobile nodes, this energy constraint may not be valid, since their motion might need much more energy, but links instabilities and short time windows available to receive and transmit data. Therefore, it is better to communicate as little as possible. For the interaction among static sensor nodes, the problems of dissemination and allocation of sensing missions are studied and a solution that explores local information is proposed and evaluated. This solution uses mobile software agents that have capabilities to take autonomous decisions about the mission dissemination and allocation using local context information. For mobile wireless sensor networks, the problem studied is how to perform handover of missions among the nodes according to their movements and locations in relation to the place where the missions have to be performed. To handle this problem, a mobile agent approach is proposed in which the agents implement the sensing missions’ migration from node to node using geographical context information to decide about their migrations. For the networks combining static and mobile sensor nodes, the cooperation among them is approached by a biologically-inspired mechanism to deliver data from the static to the mobile nodes. The data delivery mechanism explores an analogy based on the behaviour of ants building and following trails, inspired by the ant colony algorithm. The proposed solutions are flexible, being able to be applied to different application domains. Obtained experimental results provide evidence of the scalability of these proposed solutions, for example by evaluating their cost in terms of communication, among other metrics of interest for each solution. These results are compared to those achieved by reference solutions (theoretical optimum and floodingbased), providing indications of the proposed solutions’ efficiency. These results are considered close to the theoretical optimum one and significantly better than the ones achieved by flooding-based solutions.
21
Davis, Joseph A. Sr. "An analysis of network and sensor performance within IEEE 802.x wireless MESH networks in the Tactical Network Topology (TNT)." Thesis, Monterey California. Naval Postgraduate School, 2005. http://hdl.handle.net/10945/2297.
Full textAbstract:
Approved for public release, distribution is unlimitedThe objective of this research is to analyze the network performance and sensor functionality, efficacy and usability of IEEE 802.x wireless MESH networks within a DoD Tactical network environment. Multiple sensor configurations operating with wireless MESH network technologies will be researched and analyzed for performance in expeditionary environment situations. Specifically, this thesis will attempt establish the foundation for the development of wireless MESH "network health" models by examining the performance of sensors operating within a MESH network and define which network performance metrics equate to good quality of service. This research will experiment with different application, sensor, and network configurations of currently available COTS components, such as, voice, video and data hardware. This thesis will lay the groundwork for wireless network MESH predictability, which will enable the optimal use of sensors within a tactical network environment.
Lieutenant Commander, United States Navy
22
Pumpichet, Sitthapon. "Novel Online Data Cleaning Protocols for Data Streams in Trajectory, Wireless Sensor Networks." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/1004.
Full textAbstract:
The promise of Wireless Sensor Networks (WSNs) is the autonomous collaboration of a collection of sensors to accomplish some specific goals which a single sensor cannot offer. Basically, sensor networking serves a range of applications by providing the raw data as fundamentals for further analyses and actions. The imprecision of the collected data could tremendously mislead the decision-making process of sensor-based applications, resulting in an ineffectiveness or failure of the application objectives. Due to inherent WSN characteristics normally spoiling the raw sensor readings, many research efforts attempt to improve the accuracy of the corrupted or “dirty” sensor data. The dirty data need to be cleaned or corrected. However, the developed data cleaning solutions restrict themselves to the scope of static WSNs where deployed sensors would rarely move during the operation. Nowadays, many emerging applications relying on WSNs need the sensor mobility to enhance the application efficiency and usage flexibility. The location of deployed sensors needs to be dynamic. Also, each sensor would independently function and contribute its resources. Sensors equipped with vehicles for monitoring the traffic condition could be depicted as one of the prospective examples. The sensor mobility causes a transient in network topology and correlation among sensor streams. Based on static relationships among sensors, the existing methods for cleaning sensor data in static WSNs are invalid in such mobile scenarios. Therefore, a solution of data cleaning that considers the sensor movements is actively needed. This dissertation aims to improve the quality of sensor data by considering the consequences of various trajectory relationships of autonomous mobile sensors in the system. First of all, we address the dynamic network topology due to sensor mobility. The concept of virtual sensor is presented and used for spatio-temporal selection of neighboring sensors to help in cleaning sensor data streams. This method is one of the first methods to clean data in mobile sensor environments. We also study the mobility pattern of moving sensors relative to boundaries of sub-areas of interest. We developed a belief-based analysis to determine the reliable sets of neighboring sensors to improve the cleaning performance, especially when node density is relatively low. Finally, we design a novel sketch-based technique to clean data from internal sensors where spatio-temporal relationships among sensors cannot lead to the data correlations among sensor streams.
23
Stucki, Eric Thomas. "Medium Access Control and Networking Protocols for the Intra-Body Network." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1182.pdf.
Full text
24
Milicic, Gregory J. "Analysis of hardware requirements for airborne tactical mesh networking nodes." Thesis, Monterey California. Naval Postgraduate School, 2005. http://hdl.handle.net/10945/2218.
Full textAbstract:
Approved for public release, distribution is unlimitedWireless mesh mobile ad hoc networks (MANETs) provide the military with the opportunity to spread information superiority to the tactical battlespace in support of network-centric warfare (NCW). These mesh networks provide the tactical networking framework for providing improved situational awareness through ubiquitous sharing of information including remote sensor and targeting data. The Naval Postgraduate School's Tactical Network Topology (TNT) project sponsored by US Special Operations Command seeks to adapt commercial off the shelf (COTS) information technology for use in military operational environments. These TNT experiments rely on a variety of airborne nodes including tethered balloon and UAVs such as the Tern to provide reachback from nodes on the ground to the Tactical Operations Center (TOC) as well as to simulate the information and traffic streams expected from UAVs conducting surveillance missions and fixed persistent sensor nodes. Airborne mesh nodes have unique requirements that can be implemented with COTS technology including single board computers and compact flash.
Lieutenant, United States Navy
25
Dunkels, Adam. "Programming Memory-Constrained Networked Embedded Systems. PhD thesis." Doctoral thesis, Västerås : Department of Computer Science and Electronics, Mälardalen University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-173.
Full text
26
Mahfoudh, Saoucene. "Energy efficiency in wireless ad hoc and sensor networks : routing, node activity scheduling and cross-layering." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2010. http://tel.archives-ouvertes.fr/tel-00757251.
Full textAbstract:
In this thesis, we consider wireless ad hoc and sensor networks where energy matters. Indeed, sensor nodes are characterized by a small size, a low cost, an advanced communication technology, but also a limited amount of energy. This energy can be very expensive, difficult or even impossible to renew. Energy efficient strategies are required in such networks to maximize network lifetime. We distinguish four categories of strategies: 1. Energy efficient routing, 2. Node activity scheduling, 3. Topology control by tuning node transmission power and 4. Reduction of the volume of information transferred. Our contribution deals with energy efficient routing and node activity scheduling. For energy efficient routing, the idea consists in reducing the energy spent in the transmission of a packet from its source to its destination, while avoiding nodes with low residual energy. The solution we propose, called EOLSR, is based on the link state OLSR routing protocol. We show by simulation that this solution outperforms the solution that selects routes minimizing the end-to-end energy consumption, as well as the solution that builds routes based on node residual energy. We then show how we can improve the benefit of energy efficient routing using cross layering. Informa- tion provided by the MAC layer improves the reactivity of the routing protocol and the robustness of routes. Moreover, taking into account the specificities of some applications like data gathering allows the routing protocol to reduce its overhead by maintaining routes only to the sink nodes. Concerning node activity scheduling, since the sleep state is the least power consuming state, our aim is to schedule node state between sleeping and active to minimize energy consumption while ensuring network and application functionalities. We propose a solution, called SERENA, based on node coloring. The idea is to assign a color to each node, while using a small number of colors and ensuring that two nodes with the same color can transmit without interfering. This color is mapped into a slot in which the node can transmit its messages. Consequently, each node is awake during its slot and the slots granted to its one-hop neighbors. It sleeps the remaining time. We show how this algorithm can adapt to different application requirements: broadcast, immediate acknowledgement of unicast transmissions... The impact of each additional requirement is evaluated by simulation. An originality of this work lies in taking into account real wireless propagation conditions. Color conflicts are then possible. A cross-layering approach with the MAC layer is used to solve these conflicts. We also show how cross-layering with the application layer can improve the coloring per- formance for data gathering applications. This work has been done for the ANR OCARI project whose aim is to design and implement a wireless sensor network for applications in harsh environments such as power plants and war- ships. The network layer including SERENA and EOLSR has been specified and is now under implementation.
27
Meghji, Mahir Lumumba. "On a Joint Physical Layer and Medium Access Control Sublayer Design for Efficient Wireless Sensor Networks and Applications." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/590.
Full textAbstract:
Wireless sensor networks (WSNs) are distributed networks comprising small sensing devices equipped with a processor, memory, power source, and often with the capability for short range wireless communication. These networks are used in various applications, and have created interest in WSN research and commercial uses, including industrial, scientific, household, military, medical and environmental domains. These initiatives have also been stimulated by the finalisation of the IEEE 802.15.4 standard, which defines the medium access control (MAC) and physical layer (PHY) for low-rate wireless personal area networks (LR-WPAN).
Future applications may require large WSNs consisting of huge numbers of inexpensive wireless sensor nodes with limited resources (energy, bandwidth), operating in harsh environmental conditions. WSNs must perform reliably despite novel resource constraints including limited bandwidth, channel errors, and nodes that have limited operating energy. Improving resource utilisation and quality-of-service (QoS), in terms of reliable connectivity and energy efficiency, are major challenges in WSNs. Hence, the development of new WSN applications with severe resource constraints will require innovative solutions to overcome the above issues as well as improving the robustness of network components, and developing sustainable and cost effective implementation models.
The main purpose of this research is to investigate methods for improving the performance of WSNs to maintain reliable network connectivity, scalability and energy efficiency. The study focuses on the IEEE 802.15.4 MAC/PHY layers and the carrier sense multiple access with collision avoidance (CSMA/CA) based networks. First, transmission power control (TPC) is investigated in multi and single-hop WSNs using typical hardware platform parameters via simulation and numerical analysis. A novel approach to testing TPC at the physical layer is developed, and results show that contrary to what has been reported from previous studies, in multi-hop networks TPC does not save energy.
Next, the network initialization/self-configuration phase is addressed through investigation of the 802.15.4 MAC beacon interval setting and the number of associating nodes, in terms of association delay with the coordinator. The results raise doubt whether that the association energy consumption will outweigh the benefit of duty cycle power management for larger beacon intervals as the number of associating nodes increases.
The third main contribution of this thesis is a new cross layer (PHY-MAC) design to improve network energy efficiency, reliability and scalability by minimising packet collisions due to hidden nodes. This is undertaken in response to findings in this thesis on the IEEE 802.15.4 MAC performance in the presence of hidden nodes. Specifically, simulation results show that it is the random backoff exponent that is of paramount importance for resolving collisions and not the number of times the channel is sensed before transmitting. However, the random backoff is ineffective in the presence of hidden nodes. The proposed design uses a new algorithm to increase the sensing coverage area, and therefore greatly reduces the chance of packet collisions due to hidden nodes. Moreover, the design uses a new dynamic transmission power control (TPC) to further reduce energy consumption and interference. The above proposed changes can smoothly coexist with the legacy 802.15.4 CSMA/CA.
Finally, an improved two dimensional discrete time Markov chain model is proposed to capture the performance of the slotted 802.15.4 CSMA/CA. This model rectifies minor issues apparent in previous studies. The relationship derived for the successful transmission probability, throughput and average energy consumption, will provide better performance predictions. It will also offer greater insight into the strengths and weaknesses of the MAC operation, and possible enhancement opportunities.
Overall, the work presented in this thesis provides several significant insights into WSN performance improvements with both existing protocols and newly designed protocols.
Finally, some of the numerous challenges for future research are described.
28
Lönn, Johan, and Jonas Olsson. "ZigBee for wireless networking." Thesis, Linköping University, Department of Science and Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2885.
Full textAbstract:
The past several years have witnessed a rapid development in the wireless network area. So far wireless networking has been focused on high-speed and long range applications. However, there are many wireless monitoring and control applications for industrial and home environments which require longer battery life, lower data rates and less complexity than those from existing standards. What the market need is a globally defined standard that meets the requirement for reliability, security, low power and low cost. For such wireless applications a new standard called ZigBee has been developed by the ZigBee Alliance based upon the IEEE 802.15.4 standard.
The aim of this diploma work is to design fully functional ZigBee and IEEE 802.15.4 modules, and to evaluate an application in a sensor network.
This diploma work has resulted in two fully functional ZigBee and IEEE 802.15.4 modules, respectively. It is also shown that ZigBee sensors can be networked wirelessly. Eventually it is the authors hope that the modules will be used within ITN, and also be developed further for new applications.
29
Chis, Andréea. "Méthodes et outils pour la compilation et l'optimisation logicielle des systèmes embarqués sans fil dédiés à des applications." Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2012. http://tel.archives-ouvertes.fr/tel-00768830.
Full textAbstract:
Les réseaux de capteurs communicants sont fortement contraints en ressources: calcul, mémoire et énergie. Dans ce contexte, une attention particulière doit être portée lors de la conception des application, des protocoles de communication et du système d'exploitation qui vont être exécutés sur les plateformes. Le but de cette thèse a été d'adapter les modèles de logiciels utilisés classiquement pour la programmation d'applications au domaine des réseaux de capteurs et de proposer des méthodes et outils permettant de construire une version adaptée du logiciel devant s'exécuter sur les cibles à partir d'un modèle de l'application. Une des composantes qui consomment le plus d'énergie d'un micro-capteur c'est son interface radio. Le comportement d'une couche MAC peut être exprimé comme un automate temporisé avec des états fixes (qui correspondent à des états spécifiques du dispositif physique) ou des états libres (dont le choix de mappage est laissé au programmeur). Le comportement d'un périphérique radio peut lui-même être exprimé comme un automate temporisé composé d'états transitoires (avec durée fixe de l'état) et non transitoires (avec une durée illimitée mais avec une contrainte de temps minimal à passer dans l'état). Le problème de mapper un état software libre de durée fixe sur un chemin dans l'automate du dispositif physique en minimisant l'énergie est prouvé NP-complète. Une heuristique permettant de mapper les états libres d'un automate correspondant à un protocole software sur des états ou chemins entre les états d'un dispositif physique est proposée. L'approche amène à des gains théoriques de 60% pour B-MAC- une couche MAC classique. Pour les 2 catégories de système d'exploitation dédiés à ce type d'applications (modèle à événements et modèle à threads), des squelettes de code sont générés. Adapté a Mantis OS, le squelette de code pour B-MAC confirme en simulation sur la plateforme Worldsens les gains théoriques. Des experimentations sur la plateforme réelle Senslab ont prouvé que l'optimisation en terme d'energie ne modifie pas les performances fonctionnelles du protocole.
30
Kaba, James, and Paul Hashfield. "AD HOC NETWORKING OVERVIEW AND APPLICATION TO A BATTLEFIELD SENSORS SYSTEM." International Foundation for Telemetering, 2003. http://hdl.handle.net/10150/606673.
Full textAbstract:
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, NevadaAd hoc networking protocols enable the formation of self-organizing networks with automatic selfhealing operation in dynamic environments. There are a number of existing or planned ad hoc implementations and a body of research on protocols and performance. Ad Hoc technologies promise significant impact in future communications architectures. This paper presents a general overview of ad hoc networking and presents specific examples, including a recent implementation of a prototype ad hoc networked sensor system. The protocols used have unique characteristics derived by tailoring particular protocols to the specific application requirements. The potential relevance of ad hoc networking to possible telemetry applications is discussed.
31
Claeys, Timothy. "Sécurité pour l'internet des objets : une approche des bas en haut pour un internet des objets sécurisé et normalisé." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAM062.
Full textAbstract:
La rapide expansion du marché de l’IoT a permis de relier de plus en plus de matériels bon marché àl’Internet. Pour bon nombre de ces objets, la sécurité ne constitue pas une priorité. En raison de leursfonctionnalités avancées de détection et de manipulation, ces produits IoT mal sécurisés mettent en dangerla vie privée et la sécurité de leurs utilisateurs.Bien que l’IoT englobe des objets connectés de capacités variables, dans ces travaux, nous nous concentronssur les équipements contraints en énergie, en ressources mémoires, et à faible puissance de calcul.Ces restrictions limitent non seulement la possibilité de traitements, mais aussi la capacité à protéger lesdonnées et les utilisateurs. Afin de sécuriser l’IoT, nous identifions plusieurs éléments de bases permettantde fournir des services de sécurité sur l’ensemble d’un équipement.L’implémentation des mécanismes de sécurité au niveau matériel constitue un premier pilier pourl’IoT sécurisé. Diverses fonctions, telles que le démarrage sécurisé, l’attestation à distance et les mises àjour "over-the-air", dépendent en effet fortement de son support. Comme l’implémentation de la sécuritématérielle est souvent coûteuse et ne peut être appliquée aux systèmes existants, nous étudions l’attestationpurement logicielle. Cette méthode fournit une racine de confiance aux systèmes distants qui ne supportentpas la sécurité au niveau matériel. Dans le cadre de l’attestation à distance, l’identification de l’appareilest primordiale. Une partie de ce travail est donc consacrée à l’étude des identificateurs physiques desdispositifs et de leur fiabilité.L’IoT sécurisé repose sur un deuxième élément clé: la cryptographie. Cette dernière est abondammentutilisée par tous les autres mécanismes de sécurité et largement étudiée. Nous étudions les performancesdes algorithmes cryptographiques récents pour les dispositifs contraints.Un troisième élément central pour sécuriser l’IoT est la capacité de la pile protocolaire à sécuriser lescommunications. Nous montrons par exemple qu’il est possible d’exploiter la tolérance du BLE à la dérived’horloge pour établir un canal couvert. D’autre part, il est possible de monter une attaque de déni deservice en exploitant les phases énergivores du réseau, notamment la phase d’attache. Nous proposonsdans ces travaux un algorithme défensif qui réduit quasiment à néant les surcoûts liés à la connexion auréseau.Les architectures de sécurité constituent le dernier pilier pour la sécurité de l’IoT. Elles permettent eneffet de guider le déploiement d’un IoT sécurisé à grande échelle. Après avoir étudié la proposition de l’IETFde schéma d’authentification et d’autorisation pour l’IoT, nous proposons deux pistes d’amélioration de lasécurité.Enfin, la mise en place d’une architecture de sécurité implique le choix du protocole. Dans le contextedes réseaux contraints énergétiquement, le critère déterminant sera la consommation. Même si, àl’avenir, l’IoT utilisera principalement le paradigme d’objets sécurisés pour protéger les données, tant queces derniers ne seront pas largement supportés, de nombreux produits IoT s’appuieront sur les protocolesde sécurité traditionnels tels que TLS et DTLS. C’est pourquoi nous réalisons une étude de performance surla partie la plus critique de ces protocoles : l’établissement du secret partagé. Nous montrons que, mêmesi le "handshake" DTLS utilise moins de paquets pour établir le secret partagé, TLS obtient des meilleursrésultats dans les réseaux avec pertesThe rapid expansion of the IoT has unleashed a tidal wave of cheap Internet-connected hardware. Formany of these products, security was merely an afterthought. Due to their advanced sensing and actuatingfunctionalities, poorly-secured IoT devices endanger the privacy and safety of their users.While the IoT contains hardware with varying capabilities, in this work, we primarily focus on the constrainedIoT. The restrictions on energy, computational power, and memory limit not only the processingcapabilities of the devices but also their capacity to protect their data and users from attacks. To secure theIoT, we need several building blocks. We structure them in a bottom-up fashion where each block providessecurity services to the next one.The first cornerstone of the secure IoT relies on hardware-enforced mechanisms. Various security features,such as secure boot, remote attestation, and over-the-air updates, rely heavily on its support. Sincehardware security is often expensive and cannot be applied to legacy systems, we alternatively discusssoftware-only attestation. It provides a trust anchor to remote systems that lack hardware support. In thesetting of remote attestation, device identification is paramount. Hence, we dedicated a part of this work tothe study of physical device identifiers and their reliability.The IoT hardware also frequently provides support for the second building block: cryptography. Itis used abundantly by all the other security mechanisms, and recently much research has focussed onlightweight cryptographic algorithms. We studied the performance of the recent lightweight cryptographicalgorithms on constrained hardware.A third core element for the security of the IoT is the capacity of its networking stack to protect the communications.We demonstrate that several optimization techniques expose vulnerabilities. For example,we show how to set up a covert channel by exploiting the tolerance of the Bluetooth LE protocol towardsthe naturally occurring clock drift. It is also possible to mount a denial-of-service attack that leverages theexpensive network join phase. As a defense, we designed an algorithm that almost completely alleviates theoverhead of network joining.The last building block we consider is security architectures for the IoT. They guide the secure integrationof the IoT with the traditional Internet. We studied the IETF proposal concerning the constrainedauthentication and authorization framework, and we propose two adaptations that aim to improve its security.Finally, the deployment of the IETF architecture heavily depends on the security of the underlying communicationprotocols. In the future, the IoT will mainly use the object security paradigm to secure datain flight. However, until these protocols are widely supported, many IoT products will rely on traditionalsecurity protocols, i.e., TLS and DTLS. For this reason, we conducted a performance study of the most criticalpart of the protocols: the handshake phase. We conclude that while the DTLS handshake uses fewerpackets to establish the shared secret, TLS outperforms DTLS in lossy networks
32
Brun-Laguna, Keoma. "Deterministic Networking for the Industrial IoT." Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS157.
Full textAbstract:
L’Internet des Objets (IoT) a évolué d’un toaster connecté en 1990 vers des réseaux de centaines de petit appareils utilisés dans des applications industrielle. Ces « Objects » sont habituellement de petit appareils électroniques capable de mesurer une valeur physique (température, humidité, etc.) et/ou d’agir sur le monde physique (pump, valve, etc.). De part leur faible coût et leur facilité de déploiement, ces réseaux sans fil alimentés par batteries ont étés rapidement adoptés. La promesse des communications sans fil est d’offrir une connectivité similaire au réseau filaires. De nombreuses amélioration ont étés fait dans ce sens, mais plein de défis restent à surmonter car les applications industrielles ont de fortes exigences opérationnelles. Cette section de l’IoT s’appelle l’Internet Industriel des Objets. La principale exigence est la fiabilité. Chaque bout d’information transmit dans le réseau ne doit pas être perdu. Des solutions commerciales sont aujourd’hui accessibles et propose des fiabilités de l’ordre de 99.999 %. C’est à dire, pour chaque centaine de paquet d’information généré, moins d’un est perdu. Vient ensuite la latence et l’efficience énergétique. Comme ces appareils sont alimentés par des batteries, ils doivent consommer le moins possible et être capable d’opérer pendant des années. La prochaine étape pour l’IoT est d’être appliqué au applications nécessitant des garanties de latence. Les technologies de l’IIoT sont maintenant adoptés par de nombreuses entreprises autour du monde et sont maintenant des technologies éprouvées. Néanmoins des défis restent à accomplir et certaines limites de ces technologies ne sont pas encore connues. Dans ce travail, nous nous adressons au réseaux sans fils fondés sur TSCH dont nous testons les limites de latence et de durée de vie dans des conditions réelles. Nous avons collecté plus de 3M statistiques réseaux et 32M données de capteurs dans 11 déploiements sur un total de 170,037 heures machines dans des environnements réels ainsi que dans des bancs d’essais. Nous avons réuni ce que nous pensons être le plus grand jeu de données de réseau TSCH disponible à la communauté réseau. En s’appuyant sur ces données et sur notre expérience des réseaux sans fils en milieu réel, nous avons étudié les limites des réseaux TSCH et avons fourni des méthodes et outils qui permettent d’estimer des performances de ces réseaux dans diverses conditions. Nous pensons avoir assemblé les bons outils pour que les architectes de protocoles réseaux construise des réseaux déterministes pour l’IIoTThe Internet of Things (IoT) evolved from a connected toaster in 1990 to networks of hundreds of tiny devices used in industrial applications. Those “Things” usually are tiny electronic devices able to measure a physical value (temperature, humidity, etc.) and/or to actuate on the physical world (pump, valve, etc). Due to their cost and ease of deployment, battery-powered wireless IoT networks are rapidly being adopted. The promise of wireless communication is to offer wire-like connectivity. Major improvements have been made in that sense, but many challenges remain as industrial application have strong operational requirements. This section of the IoT application is called Industrial IoT (IIoT). The main IIoT requirement is reliability. Every bit of information that is transmitted in the network must not be lost. Current off-the-shelf solutions offer over 99.999% reliability. That is, for every 100k packets of information generated, less than one is lost. Then come latency and energy-efficiency requirements. As devices are battery-powered, they need to consume as little as possible to be able to operate during years. The next step for the IoT is to target time-critical applications. Industrial IoT technologies are now adopted by companies over the world, and are now a proven solution. Yet, challenges remain and some of the limits of the technologies are still not fully understood. In this work we address TSCH-based Wireless Sensor Networks and study their latency and lifetime limits under real-world conditions. We gathered 3M network statistics 32M sensor measurements on 11 datasets with a total of 170,037 mote hours in real-world and testbeds deployments. We assembled what we believed to be the largest dataset available to the networking community. Based on those datasets and on insights we learned from deploying networks in real-world conditions, we study the limits and trade-offs of TSCH-based Wireless Sensor Networks. We provide methods and tools to estimate the network performances of such networks in various scenarios. We believe we assembled the right tools for protocol designer to built deterministic networking to the Industrial IoT
33
Younus, Muhammad Usman. "Contribution to energy optimization in WSN : routing based on RL and SDN oriented routing." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30052.
Full textAbstract:
Les réseaux de capteurs sans fil (WSN) ont atteint une grande importance, car ces réseaux permettent des observations réelles en raison de leur déploiement technique dans de nombreuses applications mondiales et de la faible consommation énergétique des appareils informatiques. Ces réseaux se composent de plusieurs micro-capteurs de faible puissance et à moindre coût. La communication multi-sauts à faible débit est faite par une petite partie des nœuds, mais avec une bande passante limitée. Par conséquent, les appareils individuels transmettent leurs données à un dispositif central (par exemple, un nœud-puits) en détectant le milieu environnant à travers les multi-sauts. Les applications de WSN comprennent principalement la surveillance des soins de santé, la surveillance de l’environnement, la surveillance industrielle, le suivi des cibles et de nombreux autres domaines commerciaux. Ces types d’applications WSN sont des nœuds de faible puissance qui restent actifs après leur déploiement initial à long terme sans aucunes commandes externes. Un nœud déchargera sa batterie en quelques jours lorsqu’aucune approche écoénergétique n’est utilisée pour la communication. Cela a conduit les chercheurs à élaborer des protocoles de routage qui devraient être en mesure de minimiser la consommation d’énergie. La consommation d’énergie des WSN peut être réduite en gérant les ressources de réseau. À cette fin, certaines architectures réseaux (c.-à-d. le réseau à définition logicielle (SDN)) et les techniques d’apprentissage (c.-à-d. l’apprentissage par renforcement (RL)) peuvent être utilisées pour la gestion du réseau (routage) permettant de réduire la consommation d’énergie des nœuds. L’une des solutions proposées est la technique RL pour surmonter le problème de routage. RL est une catégorie d’apprentissage automatique (ML) qui fournit un cadre pour apprendre le système à partir de ses interactions antérieures avec l’environnement afin de sélectionner l’action future efficacement. Dans RL, l’apprenant est considéré comme un agent qui interagit avec son environnement pour sélectionner la prochaine action qui serait appliquée à l’environnement. De plus, il reçoit un retour, en termes de récompense, qui peut être positif ou négatif, selon l’action effectuée. Par exemple, pour prendre la décision de routage, le routeur interagit avec les nœuds voisins pour sélectionner le prochain expéditeur pour la transmission du paquet de données jusqu’à la destination (c.-à-d. la station de base (BS) ou le nœud-puits). Dans ce cas, le routeur est un agent, les nœuds voisins se comportent comme l’environnement de cet agent, et l’action est de choisir les prochains nœuds voisins pour envoyer les paquets de données. RL peut être un bon choix pour trouver une route où la consommation d’énergie réseau est réduite afin d’améliorer la durée de vie. Une autre solution proposée est le concept de SDN pour dépasser le problème de routage. Il peut être défini comme une architecture émergente des réseaux pour extraire la partie contrôle du réseau qui est précisément programmable. Ce nouveau paradigme est considérablement prometteur pour gérer l’évolution et la gestion de réseau. L’idée de base derrière ce concept est la même que les ressources informatiques et le stockage. Dans cette thèse, nous proposons des mécanismes écoénergétiques dans les WSN à des fins de routage pour prolonger la durée de vie du réseauWireless Sensor Networks (WSNs) have achieved great significance as these networks allow real-world observations because of their technical deployment into many global applications and low-power usage of computing devices. These networks consist of several on-chip sensors that are low-power and low-cost. The multi-hop communication at low data rates is made by a small range of communication of sensor nodes, but with limited bandwidth. Therefore, individual devices transmit their data to a central device (e.g., sink) by detecting the surrounding environment through the multiple-hops. WSNs applications mainly include healthcare monitoring, environmental monitoring, industrial monitoring, target tracking, and many other commercial areas. Such types of WSNs applications are low-powered nodes that remain active after their initial deployment for long-term without any external control. A node will discharge its battery in a couple of days when no energy-efficient approach is used for communication. It leads the researchers to develop routing protocols that should be able to minimize energy consumption. WSNs energy consumption can be reduced by managing network resources. For this purpose, some networking architectures (i.e., Software Defined Networking (SDN)) and learning techniques (i.e., Reinforcement Learning (RL)) can be used for network management (routing) that lead to reduce the energy consumption of sensor nodes. One of the solutions being proposed is the RL technique to overcome the routing problem. RL is a class of machine learning (ML) which provides a framework to learn the system from its previous interactions with environment to select future action efficiently. In RL, the learner is known as an agent that interacts with its environment to select the next action that would be applied to the environment. Also, it gets the feedback in terms of reward that can be positive or negative according to performed action. For example, to make the routing decision, the router interacts with neighboring nodes to select the next forwarder for the data packet transmission up to the destination (i.e., Base Station (BS) or sink node). In such case the router is an agent, the neighboring nodes behave as an environment for that agent, and actions select the next neighboring nodes to send the data packets. RL can be a good choice to optimize a routing path where network energy consumption is reduced to enhance the lifetime. Another proposed solution is the concept of SDN to overcome the routing problem. It can be defined as an emergent architecture of networks to carry out the decoupling of network control that is precisely programmable. This novel paradigm is dramatically promising to enable evolution and network management. The basic idea behind this concept is the same as computing resources and storage. In this thesis, we propose energy-efficient mechanisms in WSNs for the routing purposes to extend the network’s lifetime. The proposed work is performed by using two different techniques, namely as RL and SDN. The first part of this thesis provides a comprehensive detail of existing energy-efficient mechanisms; while, the second part contains the proposed techniques
34
Zeghilet, Houda. "Le routage dans les réseaux de capteurs multimédia." Phd thesis, Université de Lorraine, 2013. http://tel.archives-ouvertes.fr/tel-00922266.
Full textAbstract:
Aujourd'hui, la prolifération de matériel peu coûteux tels que les caméras et les microphones capables de capturer du contenu multimédia de façon ubiquitaire a conduit à l'émergence des réseaux de capteurs sans fil multimédia/vidéo (RCSFM /RCSFV). En conséquence, un grand éventail d'applications peuvent être projetées dans de nombreux domaines de la vie de tous les jours. Par rapport aux réseaux de capteurs traditionnels (RCSF), les RCSFVs présentent des défis uniques principalement en raison de la grande quantité de données à capturer et à transmettre au-dessus d'un réseau contraint en ressources. Un certain niveau de qualité de service peut être exigé en termes de délai, bande passante, gigue, fiabilité, qualité de perception de la vidéo, etc. Dans ce travail, nous visons le problème du routage de données vidéo dans un RCSF. De nombreux protocoles de routage ont été proposés dans la littérature. Ils peuvent être qualifiés de plat ou hiérarchique en vue de l'organisation du réseau. Dans une topologie plate, tous les noeuds ont les mêmes fonctionnalités où chacun peut participer au processus de routage. Cependant, dans une architecture hiérarchique, les capteurs sont organisés en groupes (clusters) permettant une plus grande évolutivité, moins d'énergie consommée et donc une plus longue vie pour l'ensemble du réseau. Parmi les protocoles de routage existants, peu considèrent spécifiquement la transmission de données intensives comme la vidéo. Dans ce travail, nous avons d'abord proposé un protocole de routage hiérarchique appelé ELPC (Energy Level Passive Clustering) dont l'objectif principal est d'améliorer la durée de vie du réseau en présence de flux vidéo. Ceci est obtenu grâce à l'équilibrage des charges au moment de la construction de la topologie où le rôle de tête de groupe est alterné entre les noeuds candidats en fonction de leur niveau d'énergie. La deuxième contribution consiste en un protocole de routage multichemin qui prend les interférences inter-chemin en considération. En effet, en permettant la transmission de plusieurs flux concurrents, le délai de bout en bout se trouve réduit et les besoins de l'application en termes de bande passante peuvent être satisfaits. Au lieu de supprimer complètement les interférences, notre protocole de routage multichemin tente de les minimiser en se basant sur l'ajout d'informations supplémentaires sur les noeuds voisins dans les messages de construction de la topologie. De plus, nous proposons un schéma de files d'attente à priorités multiples où l'influence des types de données dans une vidéo est considérée. Les résultats des simulations montrent que l'utilisation de chemins moins interférents combinée à un régime de multipriorité permet une meilleure qualité vidéo.
35
Makkaoui, Leila. "Compression d'images dans les réseaux de capteurs sans fil." Phd thesis, Université de Lorraine, 2012. http://tel.archives-ouvertes.fr/tel-00795503.
Full textAbstract:
Cette thèse forme une contribution au problème de la conservation de l'énergie dans le cas particulier des réseaux de capteurs d'images, où une partie voire tous les nœuds du réseau sont équipés d'une petite caméra à technologie CMOS. Les images engagent des volumes de données très largement supérieurs aux mesures scalaires classiques telles que la température, et donc des dépenses énergétiques plus élevées. L'émetteur radio étant l'un des composants les plus gourmands en énergie, il est évident que la compression de l'image à la source peut réduire significativement l'énergie dépensée pour la transmission de l'image, tant au niveau du nœud caméra que des nœuds formant le chemin jusqu'au point de collecte. Toutefois, les méthodes de compression bien connues (JPEG, JPEG2000, SPIHT) sont mal adaptées à la limitation des ressources de calcul et de mémoire caractéristiques des nœuds-capteurs. Sur certaines plateformes matérielles, ces algorithmes ont même un coût énergétique supérieur au gain qu'ils amènent sur la transmission. Autrement dit, le nœud caméra épuise plus vite sa batterie en envoyant des images compressées que des images non compressées. La complexité de l'algorithme de compression est donc un critère de performance aussi important que le rapport débit-distorsion. Les contributions contenues dans ce mémoire de thèses sont triples : - Tout d'abord, nous avons proposé un algorithme de compression basé sur la transformée en cosinus discrète (DCT 8 points) de complexité réduite, combinant la méthode de DCT rapide la plus efficace de la littérature (DCT de Cordic-Loeffler) à une exécution réduite aux coefficients délimités par une zone carrée de taille k<8, les plus importants dans la reconstruction visuelle. Avec cette approche zonale, le nombre de coefficients à calculer, mais aussi à quantifier et encoder par bloc de 8x8 pixels est réduit à k^2 au lieu de 64, ce qui diminue mécaniquement le coût de la compression. - Nous avons ensuite étudié l'impact de k, donc du nombre de coefficients sélectionnés, sur la qualité de l'image finale. L'étude a été réalisée avec un jeu d'une soixantaine d'images de référence et la qualité des images était évaluée en utilisant plusieurs métriques, le PSNR, le PSNR-HVS et le MMSIM. Les résultats ont servi à identifier, pour un débit donné, la valeur limite de k qu'on peut choisir (statistiquement) sans dégradation perceptible de la qualité, et par conséquent les limites posées sur la réduction de la consommation d'énergie à débit et qualité constants. - Enfin, nous donnons les résultats de performances obtenus par des expérimentations sur une plateforme réelle composée d'un nœud Mica2 et d'une caméra Cyclops afin de démontrer la validité de nos propositions. Dans un scénario considérant des images de 128x128 pixels encodées à 0,5 bpp par exemple, la dépense d'énergie du nœud caméra (incluant compression et transmission) est divisée par 6 comparée au cas sans compression, et par 2 comparée au cas de l'algorithme JPEG standard.
36
Harchi, Said. "Un protocole de session dans les réseaux de capteurs sans fils." Phd thesis, Université de Lorraine, 2013. http://tel.archives-ouvertes.fr/tel-00961091.
Full textAbstract:
Les réseaux de capteurs sans fils sont de plus en plus utilisés dans des applications de surveillance de grands systèmes (feux de forêt, gaz dans les galeries minières, éthologie, ...). Une caractéristique de ces applications est que la topologie du réseau va être dynamique : soit les capteurs sont géographiquement mobiles (dispersion d'une nappe de pétrole), soit les conditions environnementales évoluent et modifient les capacités de communication des capteurs entre eux. Aussi, d'un système connexe, on peut évoluer vers un système clustérisé qui présente une rupture de la connectivité globale, et donc du système d'information. Une solution consiste à utiliser un (ou des) collecteur(s) des mesures (par exemple un robot mobile) qui va rétablir une connectivité discrète pour reconstituer à des échéances fixes un système d'information cohérent. Nous avons proposé un algorithme de clustering du réseau de capteurs sans fils adapté à la dynamique de sa topologie. La métrique choisie prend en compte la densité et la mobilité des nœuds, ainsi que leur énergie résiduelle. Ensuite, nous avons conçu un protocole de couche session permettant au collecteur de reconstruire le contexte de communication avec les clusters précédemment visités, sachant qu'ils ont pu évoluer en nombre, dispersion, fusion, ... Pour ce faire, il faut générer dynamiquement une trajectoire optimale du collecteur, en se basant sur un modèle d'estimation de la topologie, en prenant en compte les exigences applicatives (fréquence et volume des informations remontées). Pour la validation de l'algorithme de clustering et du protocole de couche session proposés, nous avons défini un modèle de nœud capteur que nous avons intégré à l'environnement de simulation Opnet.
37
Francillon, Aurélien. "Attacking and Protecting Constrained Embedded Systems from Control Flow Attacks." Phd thesis, Grenoble INPG, 2009. http://tel.archives-ouvertes.fr/tel-00540371.
Full textAbstract:
La sécurité des systèmes embarqués très contraints est un domaine qui prend de l'importance car ceux-ci ont tendance à être toujours plus connectés et présents dans de nombreuses applications industrielles aussi bien que dans la vie de tous les jours. Cette thèse étudie les attaques logicielles dans le contexte des systèmes embarqués communicants par exemple de type réseaux de capteurs. Ceux-ci, reposent sur diverses architectures qui possèdent souvent, pour des raisons des coût, des capacités de calcul et de mémoire très réduites. Dans la première partie de cette thèse nous montrons la faisabilité de l'injection de code dans des micro-contrôleurs d'architecture Harvard, ce qui était, jusqu'à présent, souvent considéré comme impossible. Dans la seconde partie nous étudions les protocoles d'attestation de code. Ceux-ci permettent de détecter les équipements compromis dans un réseau de capteurs. Nous présentons plusieurs attaques sur les protocoles d'attestation de code existants. De plus nous proposons une méthode améliorée permettant d'éviter ces attaques. Finalement, dans la dernière partie de cette thèse, nous proposons une modification de l'architecture mémoire d'un micro-contrôleur. Cette modification permet de prévenir les attaques de manipulation du flot de contrôle, tout en restant très simple a implémenter.
38
Erdene-Ochir, Ochirkhand. "Résilience et application aux protocoles de routage dans les réseaux de capteurs." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00862710.
Full textAbstract:
Les réseaux de capteurs sans fil sont constitués d'un grand nombre de nœuds, déployés pour collecter des données du monde physique (température, humidité, pollution etc.) et les transmettre, de manière autonome, vers un ou plusieurs points de collectes appelés "puits". Dans cette thèse, nous nous focalisons sur la sécurité des protocoles de routage multi-sauts, plus particulièrement, sur la notion de résilience aux attaques. Les domaines d'applications des réseaux de capteurs sont variés, allant du suivi médical à la surveillance environnementale en passant par le bâtiment intelligent ou le monitoring urbain (éclairage, pollution, relevé de compteurs d'eau/électricité/gaz etc.). Dans ces applications, les capteurs sont souvent déployés dans des environnements ouverts et accessibles permettant aux éventuels attaquants de les détruire ou de les capturer afin d'en extraire les données sensibles (clés de chiffrement, identité, adresse, etc.). La compromission des nœuds est un problème majeur pour la sécurité de réseaux de capteurs, puisqu'un adversaire peut s'introduire à l'intérieur du périmètre de sécurité. Les méthodes traditionnelles, basées sur la cryptographie, permettent d'obtenir une sécurité de base (authentification, confidentialité, intégrité, non répudiation etc.), mais ne permettent pas toujours de se prémunir contre les attaques dues à la compromission des nœuds (réplication des nœuds, Sybil, Selective forwarding, Blackhole, Sinkhole, Wormhole etc.). Dans le but d'apporter des solutions algorithmiques complémentaires aux solutions cryptographiques, nous étudions la résilience des protocoles de communication en présence d'adversaires internes visant à perturber le routage de l'information à travers le réseau. Dans un premier temps, nous introduisons le concept de résilience. Notre objectif est de proposer une définition explicitant le terme de résilience dans notre contexte et une métrique, permettant de comparer efficacement les protocoles de routage. L'originalité de cette métrique est d'utiliser à la fois une représentation graphique et une méthode de calcul quantitative liée à celle-ci. La représentation graphique à deux dimensions permet une vision synthétique de la résilience des protocoles selon plusieurs paramètres de performance. La méthode de calcul quantitative liée à cette représentation graphique agrège les valeurs des paramètres et permet de classifier les protocoles en termes de résilience. Grâce à cet outil, nous avons évalué la résilience de plusieurs protocoles de routage classiques de différentes catégories. Cette étude nous a permis d'identifier les mécanismes permettant d'améliorer la résilience des protocoles. Dans un second temps, nous proposons les mécanismes résilients de routage pour les réseaux de capteurs. Les mécanismes résilients que nous proposons consistent en trois éléments : (i) introduire un comportement aléatoire (ii) limiter la longueur des routes (iii) ajouter de la réplication de paquets. Les comportements aléatoires augmentent l'incertitude pour les adversaires, rendant les protocoles moins prévisibles, les réplications des données permettent de bénéficier la diversification des routes créées entre les sources et le puits, en améliorant ainsi le succès et l'équité de livraison et la limitation de la longueur des routes est nécessaire pour diminuer la probabilité qu'un paquet tombe sur un nœud attaquant en route. La connexité entre les capteurs et le puits est ainsi augmentée. Grâce à notre métrique de résilience, nous avons proposé une nouvelle taxonomie de résilience. Selon cette taxonomie, le routage par gradient et la marche aléatoire biaisée avec les mécanismes proposés sont les plus résilients. Nous avons donc évalué par la suite le routage par gradient en cas d'attaques combinées pour approfondir notre étude, mais aussi pour savoir si ces mécanismes proposés permettent d'augmenter la résilience même en cas d'attaques plus complexes, visant différents aspects du routage (construction des routes, paquets de contrôle, etc.). Nous avons introduit plusieurs valeurs de biais aux variantes aléatoires du routage par gradient pour étudier l'influence de l'entropie et nous les avons comparées à sa version classique. Nous avons également évalué leur résilience en introduisant deux types de réplications (uniformes et adaptatives). Sans attaques, ce sont les variantes les plus biaisées sans réplications qui sont les plus performantes. En cas d'attaques peu importantes, les réplications uniformes sont plus efficaces, tandis qu'en cas d'attaques plus intenses, ce sont les réplications adaptatives qui se montrent les plus efficaces. Les études menées jusqu'à ici étaient produites par des simulations et nous avions donc besoin d'une justification théorique. Nous avons donc proposé une étude théorique de la marche aléatoire biaisée en cas d'attaques de non-retransmission des paquets. Nous avons évalué l'influence du biais, mais aussi les deux réplications que nous avions évaluées précédemment par des simulations. En premier lieu, nous avons étudié le succès de livraison et la consommation d'énergie pour tous les scénarios. Ensuite, nous les avons évalués selon notre métrique de résilience. Cette étude a permit de confirmer les résultats d'étude par simulations et elle a montré que le biais est indispensable pour la résilience et le seuil d'entropie bénéfique à la résilience est e=0.7 quand la réplication de données est introduite. En dessous de cette valeur, la marche aléatoire est inefficace à cause de la longueur de chemins trop importante. L'ensemble des travaux réalisés dans cette thèse se concentre autour de la résilience. Ce concept reste assez nouveau, en particulier dans le domaine des réseaux et télécommunications. À travers cette thèse, nous avons voulu donner notre vision sur ce thème en nous concentrant sur les problématiques de sécurité des protocoles de routage dans le contexte des réseaux de capteurs.
39
Mouradian, Alexandre. "Proposition et vérification formelle de protocoles de communications temps-réel pour les réseaux de capteurs sans fil." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00910394.
Full textAbstract:
Les RCsF sont des réseaux ad hoc, sans fil, large échelle déployés pour mesurer des paramètres de l'environnement et remonter les informations à un ou plusieurs emplacements (nommés puits). Les éléments qui composent le réseau sont de petits équipements électroniques qui ont de faibles capacités en termes de mémoire et de calcul ; et fonctionnent sur batterie. Ces caractéristiques font que les protocoles développés, dans la littérature scientifique de ces dernières années, visent principalement à auto-organiser le réseau et à réduire la consommation d'énergie. Avec l'apparition d'applications critiques pour les réseaux de capteurs sans fil, de nouveau besoins émergent, comme le respect de bornes temporelles et de fiabilité. En effet, les applications critiques sont des applications dont dépendent des vies humaines ou l'environnement, un mauvais fonctionnement peut donc avoir des conséquences catastrophiques. Nous nous intéressons spécifiquement aux applications de détection d'événements et à la remontée d'alarmes (détection de feu de forêt, d'intrusion, etc), ces applications ont des contraintes temporelles strictes. D'une part, dans la littérature, on trouve peu de protocoles qui permettent d'assurer des délais de bout en bout bornés. Parmi les propositions, on trouve des protocoles qui permettent effectivement de respecter des contraintes temporelles mais qui ne prennent pas en compte les spécificités des RCsF (énergie, large échelle, etc). D'autres propositions prennent en compte ces aspects, mais ne permettent pas de garantir des bornes temporelles. D'autre part, les applications critiques nécessitent un niveau de confiance très élevé, dans ce contexte les tests et simulations ne suffisent pas, il faut être capable de fournir des preuves formelles du respect des spécifications. A notre connaissance cet aspect est très peu étudié pour les RcsF. Nos contributions sont donc de deux types : * Nous proposons un protocole de remontée d'alarmes, en temps borné, X-layer (MAC/routage, nommé RTXP) basé sur un système de coordonnées virtuelles originales permettant de discriminer le 2-voisinage. L'exploitation de ces coordonnées permet d'introduire du déterminisme et de construire un gradient visant à contraindre le nombre maximum de sauts depuis toute source vers le puits. Nous proposons par ailleurs un mécanisme d'agrégation temps-réel des alarmes remontées pour lutter contre les tempêtes de détection qui entraînent congestion et collision, et donc limitent la fiabilité du système. * Nous proposons une méthodologie de vérification formelle basée sur les techniques de Model Checking. Cette méthodologie se déroule en trois points, qui visent à modéliser de manière efficace la nature diffusante des réseaux sans fil, vérifier les RCsF en prenant en compte la non-fiabilité du lien radio et permettre le passage à l'échelle de la vérification en mixant Network Calculus et Model Checking. Nous appliquons ensuite cette méthodologie pour vérifier RTXP.
40
Li, Yanjun. "Support de la qualité de service dans les réseaux de capteurs sans fil pour la détection d'événements." Phd thesis, Université Henri Poincaré - Nancy I, 2010. http://tel.archives-ouvertes.fr/tel-00537600.
Full textAbstract:
Cette thèse présente nos travaux à la fois théoriques et techniques sur la fourniture de la qualité de service dans les réseaux de capteurs sans fil, travaux développés principalement pour la détection en temps réel d'événements. Le premier problème fondamental pour assurer une qualité de service est la connectivité d'un réseau. La probabilité de non-isolation de nœud est donnée garantissant une borne supérieure de 1-connectivité du réseau. Un deuxième problème traité concerne la considération conjointe du problème de connectivité de communication et de couverture de détection. Ce problème étant formalisé comme un problème d'optimisation multi-objectif, un algorithme heuristique du type génétique a été développé, permettant ainsi d'aider au déploiement. Pour assurer la communication des données en temps réel et de façon fiable, un protocole de routage basé sur SPEED a été développé. Les simulations ont montré une amélioration notable de performances par rapport aux solutions existantes. Afin d'assurer la fiabilité de l'information finale, un ensemble de règles de fusion de décision a été proposé. Quant à son implémentation réelle avec moins de complexité sur des nœud de ressources limitées, trois alternatives sousoptimales ont été proposées et qui donnent des performances satisfaisantes dans des plages de rapport signal sur bruit.
41
Nefzi, Bilel. "Mécanismes auto-adaptatifs pour la gestion de la Qualité de Service dans les réseaux de capteurs sans fil." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2011. http://tel.archives-ouvertes.fr/tel-00645504.
Full textAbstract:
La plupart des réseaux de capteurs sans fill d'aujourd'hui fonctionne sur le protocole CSMA/CA. Fournir la qualité de service (QdS) dans un tel réseau est un problème difficile compte tenu de la dynamique du réseau et des contraintes en termes de ressources (énergie et mémoire). Dans cette thèse, sans changer le socle commun du CSMA/CA, nous avons proposé des mécanismes auto-adaptatifs qui permettent de gérer la QdS "best-effort" pour des applications nécessitant de la différenciation de services. Trois mécanismes sont proposés : CoSenS pour "Collecting then Sending burst Scheme", P-CoSenS qui a joute la gestion de priorités à CoSenS, et S-CoSenS qui a joute la dimension énergie à CoSenS. La dynamique du réseau est prise en compte grâce à l'auto-adaptation de périodes de collecte et de transmission en rafale. Il est à souligner que le mécanisme CoSenS permet non seulement d'améliorer les performances de CSMA/CA mais aussi de surmonter la difficulté d'ordonnancer les trafics entrant dans un nœud (routeur) car chaque paquet entrant est immédiatement retransmis vers la sortie. En effet, grâce à la pério de de collecte, les paquets entrants sont mis en file d'attente, rendant ainsi possible d'ordonnancer différemment les paquets selon leur priorité (P-CoSenS). Enfin, le compromis énergie/performance est pris en compte dans S-CoSenS. Selon l'état de l'environnement surveillé, le réseau peut se trouver dans une période où circule un trafic non urgent et souvent faible pendant laquelle il est judicieux de minimiser la consommation d'énergie et une pério de de trafic important pendant laquelle le réseau doit transporter des données urgentes pour suivre une situation alarmante de plus près. Comme CoSenS, S-CoSenS permet de s'auto-adapter dynamiquement en fonction de ces situations. L'ensemble de nos propositions est validé par simulations et CoSenS est implémenté sur une plateforme de réseau de capteurs.
42
Halász, Dávid. "Internet of Things zařízení s podporou ZigBee a 6LoWPAN." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2016. http://www.nusl.cz/ntk/nusl-363739.
Full textAbstract:
Internet of Things is the latest phenomenon in the computing industry. Even if it has not been completely defined yet, we are already surrounded by various devices connected to the Internet. This thesis project focuses on low cost and low-power wireless solutions and on the on-line backend behind the architecture. At the same time the present work also deals with Cloud Computing which can provide a highly scalable runtime environment for this backend without building an infrastructure. To handle the huge amount of data collected by billions of devices, BigData services could be used in the same cloud space. The project is a collection of the theoretical background of the Internet of Things; so as a result, it provides the reader with an overview of the concept. It also provides a walktrough of the design, implementation and testing process of a complex agricultural Internet of Things solution.
43
Lu, Hsi-Feng, and 陸錫峰. "Design of Wireless Sensor Networking Architecture." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/95266949130799308235.
Full textAbstract:
博士國立東華大學
資訊工程學系
97
Advances in micro-sensor and radio technology enable the deployment of small but smart sensor nodes for various environmental monitoring applications. Because sensor nodes may be spread over a large outdoors area or deployed in many isolate indoor space, managing numerous wireless sensor nodes directly is inefficient or impossible. Hierarchical management can reduce the costs of managing nodes and of the communication among them. This study presents an algorithm for self-organization management of higher-level nodes, contesting member nodes using multi-hop to form hierarchical clusters, and applying the “20/80 Rule” to determine the ratio of headers to member nodes. Furthermore, the broadcast tree is constructed with the minimum number of hops. The simulation indicates how the 20/80 Rule affects the formation of clusters between sensor nodes. From the observations of simulation results, comparing with the same type approach, the proposed algorithm has lower cover loss about 22%~6% at the same conditions that 100 nodes deployed randomly in different sensor field areas (100*100, 200*200, and 300*300). In addition, the simulation shows too high the ratio of header and member is waste. The higher density achieves the stronger link between the nodes, and the stronger link achieves the lower cover loss. From the observations of above results, we found the density and proper proportional that are very important factors for self-organization mechanism of wireless sensor network. This study also proposed a novel middleware of wireless sensor network for tele-homecare systems and it is suitable for all kinds of wireless sensor network. The architecture includes three layers: device management layer, data management layer and application layer. Vital signs sensing is achieved by wireless sensor node integrated with medical device or by sensors connected with serial link. The two-layer middleware is defined as the software above the medical sensor network but below the application program that provides a common programming abstraction for tele-homecare system. An application— Tele-Homecare Household Monitor System— was implemented and evaluated based on the proposed middleware. The performance of the middleware also was discussed and compared in the case of with/without aggregation and three different level of the aggregation implementation. To increase power efficiency and prolong the system life-time, the aggregation functions should be implemented on the sensor node of the wireless sensor network if this is feasible. To minimize the message delay, the aggregation functions should be implemented on cluster head. Therefore, the aggregation function should be implemented in every level of the wireless sensor network if the wireless nodes have enough memory and computation power for it. Good message aggregation and filtering significantly reduce the number of messages transmitted and stored in the system, and could translate the sensed readings into useful and meaningful information. For the variety of interfaces to sensor network and the heterogeneous of wireless sensor network, a middleware is necessary to provide a common platform for programmer to develop WSN applications fast and easily. Moreover, this study presents an intelligent sensor network for object detection, classification, and recognition. Wireless sensors are utilized in the first layer of the network to discover the coordinates of unauthorized intruders. Cameras are activated to capture image features for object classification and recognition. Additionally, a hierarchical image extraction approach is developed to reduce processing time. Global object features such as size and motion are acquired for classification into a number of classes. If the intruder is unauthorized, the cameras will be requested to capture detailed images for object recognition. Experimental results show that the proposed system can not only detect any unauthorized intrusion efficiently, but can also classify and recognize the intruder accurately with a recognition rate of 95.4%. Finally, a SNMP-based wireless sensor network management architecture is proposed and a prototype system is implemented. This prototype system presents the necessary functions and the user interfaces for the features of wireless sensor network. It is a good start for researchers to design wireless sensor network management application.
44
Tsai, Chia-Hung, and 蔡佳宏. "Networking Issues in ZigBee Wireless Sensor Networks." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/83925947173477044638.
Full textAbstract:
博士國立交通大學
資訊科學與工程研究所
100
ZigBee is a communication standard which is considered to be suitable for wireless sensor networks. In the ZigBee protocol stack, physical and MAC layer protocols are adopted from the IEEE 802.15.4 standard [16]. ZigBee solves interoperability issues from the physical layer to the application layer. IEEE 802.15.4 defines two different modes for medium access: beaconenabled mode and beaconless mode. ZigBee supports tree and mesh network topologies. In this dissertation, we will focus on the networking issues in ZigBee beacon-enabled, tree-based networks and beaconless mesh networks. Among the well-known ZigBee topologies, ZigBee beacon-enable cluster-tree is especially suitable for wireless sensor applications with its supporting of power-saving operation and lightweight routing. The backbone of a tree network is formed by ZigBee distributed address assignment scheme. This assignment is easy to implement, but it restricts the number of children of a device and the depth of the network. We observe that the ZigBee address assignment policy is too conservative, thus usually making the utilization of the address pool poor. Those devices that can note network addresses will be isolated from the network and become orphan nodes. The orphan problem leads to the difficulty in smoothly increasing the network coverage or device density. Therefore, we propose our first research work to addressing how to alleviate the orphan problems effectively. We propose a ZigBee-compatible address assignment through temporal duplications to alleviate orphans and scale the networks. A light-weight, address-based, tree-based routing is proposed to support one-to-one routings in address-reused environments. Simulation results verify the effectiveness of the proposed solution. In our second research work, we discuss the ZigBee orphan problems in long-thin (LT) topologies. Although our temporal duplication addressing can significantly alleviate orphans in ZigBee tree networks, its deployment is still a main concern. We further observe that many monitoring applications for WSNs have adopted a path-connected-cluster (PCC) topology, where regions to be monitored are deployed with clusters of sensor nodes. Since these clusters might be physically separated, paths of sensor nodes are used to connect them together. We call such networks PCC-WSNs. PCC-WSNs may be widely applied in real situations, such as bridgeconnected islands, street-connected buildings, and pipe-connected ponds. In this work, we show that the address assignment scheme defined by ZigBee will perform poorly in terms of address utilization. We then propose a systematical solution, which includes network formation, automatic address assignment, and light-weight routing. Simulation results verify the effectiveness of the proposed solution. In our third research topic, we address the networking issues in ZigBee mesh networks. Mesh network topologies are seen as a flexible and robust manner to provide multi-hop communication. Mesh topologies offer flexibility and robustness by facilitating path formation from any source to any destination within the network. In ZigBee, stochastic address assignment mechanism is recommended in ZigBee mesh topologies such that networks can be easily scaled up without orphan problems. However, ZigBee mesh networks can only operate in beaconless mode. Power saving is a major concern in a wireless sensor network. Hence, we are interested in linking the asynchronous power-saving protocol and the energy-efficient routing problem together in ZigBee mesh networks. A cross-layer solution is proposed. On the MAC layer, we propose to use the grid-quorum system [40] to serve as the underlying power-saving framework. On the network layer, we propose to find routing paths based on the power cost incurred by grid quorums used by nodes along a path. We show how these two layers interwork with each other to support continuous queries in an energy-efficient way. Simulation results also verify the effectiveness of the proposed solution.
45
Charalambous, Charalambos. "A Biologically Inspired Networking Model for Wireless Sensor Networks." 2009. http://hdl.handle.net/1969.1/ETD-TAMU-2009-12-7508.
Full textAbstract:
Wireless sensor networks (WSNs) have emerged in strategic applications such as
target detection, localization, and tracking in battlefields, where the large-scale na-
ture renders centralized control prohibitive. In addition, the finite batteries in sensor
nodes demand energy-aware network control. In this thesis, we propose an energy-
efficient topology management model inspired by biological inter-cellular signaling
schemes. The model allows sensor nodes to cluster around imminent targets in a
purely distributed and autonomous fashion. In particular, nodes in the target vicinity
collaborate to form clusters based on their relative observation quality values. Sub-
sequently, the clustered sensor nodes compete based on their energy levels until some
of them gain active status while the rest remain idle, again according to a distributed
algorithm based on biological processes. A final phase of the model has the active
cluster members compete until one of them becomes the clusterhead. We examine the
behavior of such a model in both finite-size and infinite-size networks. Specifically,
we show that the proposed model is inherently stable and achieves superior energy
efficiency against reference protocols for networks of finite size. Furthermore, we dis-
cuss the behavior of the model in the asymptotic case when the number of nodes goes
to infinity. In this setting, we study the average number of cluster members.
46
Nadziejko, Aleksandra Katarzyna. "Wireless Sensor Networking Applied to Swarms of Aquatic Drones." Master's thesis, 2016. http://hdl.handle.net/10400.6/5875.
Full textAbstract:
Aquatic Unmanned Surface Vehicles (USV) have potential in a variety of maritime activities such as environmental monitoring or sea-life tracking. They can be applied to military missions sup¬porting army in potentially dangerous situations such as reconnaissance or surveillance. USV are capable of many tasks due to technological progress and minimization of equipment in recent years. Size and price drop while reliability improved enables development of large scale multi-agent systems consisting of autonomous USVs.
Multi-agent system of aquatic autonomous USVs may act like a distributed sensing system im¬proving the overall performance when compared to the performance of one unit of USV: more units in the system, larger monitored area. A promising approach inspired from nature is swarm intelligence, which can be found for instance in population of insects such as ants. Swarmbe¬haviour is a motion of large number of units, where each one is autonomous but only as a group they are able to solve the problem. The exchange of information between units is essential for the success of the group. Wireless Sensor Networks (WSNs) have potential as communication architecture applied to swarms.
A scenario for the communication both with and within the swarm has been proposed. The challenges implied by tough environmental conditions call for heterogeneous approach such as the one proposed in this dissertation. A communication within the swarm is held using short-range communication technology such as XBee-PRO modules. All nodes acting as sensing agents are equipped with short-range communication technology. The communication with the swarm is held using nodes acting as gateways to the shore equipped with long-range technology, such as SX1272 modules from Semtech, called LoRa. The deployment of nodes acting as gateways to the shore, called buoys, with fixed localization has been proposed. Each node in the network is aware of the GPS coordinates of buoys, thus in case of communication loss, it can orient itself in the direction of the nearest buoy, increasing chances of successful communication with the base station.
The short-range communication XBee-PRO technology has been tested in order to determine communication range with and without Line of Sight (LoS). The objective is to improve the range of the communication link, which nowadays in held via Wi-Fi in the distance around 30
m. The results were promising for real-world implementation into swarms of aquatic surface drones.Os veículos não-tripulados de superfície aquática (VNTSA) tem um enorme potencial para uma vasta gama de atividades marítimas, tais como a monitorização ambiental ou a amortização da vida marinha. Estes veículos podem ser também aplicados em miss6es militares de apoio ao exercito, em situaç6es potencialmente perigosas, tais como miss6es de reconhecimento ou de vigilância. Os USVs (VNTSA) são capazes de realizar diversas tarefas devido ao progresso tecnológico e a redução do tamanho dos equipamentos nos últimos anos. A redução do tamanho e preço, acompanhado pelo aumento da fiabilidade, permitiu o desenvolvimento de sistemas multi-agente em larga escala. Os sistemas multi-agente dos USVs autónomos aquáticos podem agir como um sistema de sen¬sores distribuídos, melhorando o desempenho global, quando comparado com o desempenho de uma unidade de USV isolado, ou seja, quantos mais unidades no sistema, maior área monitor¬izada. Uma abordagem promissora, inspirada na natureza, e inteligência de cardume (swarm intelligence), que pode ser observada na população de insetos, como por exemplo nas formigas. O comportamento do cardume (swarm) e um movimento de um grande numero de elementos, em que cada ume autónomo, porem só em grupo são capazes de resolver tarefas complexas. A troca de informaç6es entre as unidades e essencial para o sucesso do grupo. A arquitectura de comunicação aplicada a cardume pode ser suportada pelas Redes de Sensores Sem Fios (RSSF). Nesta dissertação, foi proposto um cenário para a comunicação "com" e "dentro" do cardume. Os desafios decorrentes das condiç6es ambientais difíceis exigem uma abordagem heterogénea, tal como o proposto nesta dissertação. A comunicação dentro do cardume e realizada uti¬lizando tecnologia de comunicação de curto alcance, tais como os módulos XBee-PRO. Todos os nos atuam como agentes de deteção, que estão equipados com tecnologia de comunicação de curto alcance. A comunicação com o cardume e concretizada usando os nos que funcionam como portas de comunicação (gateways) para a estação de base equipada com tecnologia de longo alcance, tais como os módulos SX1272 de Semtech, chamados LoRa. Foi ainda proposto, implementar nos, atuando como portas de comunicação (gateways) para a estação de base, designados de boias, com localização fixa. Cada no na rede tem conhecimento das coordenadas de GPS das boias, assim, em caso de perda de comunicação, podem (re)orientar-se na direção da boia mais próxima, aumentando a probabilidade de sucesso de comunicação com a estação de base. A tecnologia de comunicação de curto alcance XBee-PRO foi testada, a fim de determinar o alcance da comunicação com linha de vista e sem linha de vista. O objetivo foi melhorar o alcance da ligação (link) de comunicação, que hoje em dia e realizado via Wi-Fi, a distancias de aproximamente 30 m. Os resultados revelam potencial para a implementação no mundo real dos drones aquáticos de superfície.
47
(9850244), P. Rijal. "A Goal based Architectural Style for Wireless Sensor Networks." Thesis, 2012. https://figshare.com/articles/thesis/A_Goal_based_Architectural_Style_for_Wireless_Sensor_Networks/13387064.
Full textAbstract:
In this thesis, we will present a new architectural style which we call a goal-based architectural style and which is realised using the GORITE agent framework (Rönnquist, 2012). This architectural style provides a unified support for the spectrum of behaviour (reactive, pro-active, and social) required by sensor networks if they are to provide the levels of autonomy and adaptability that are needed.
The overall research objective is to determine whether a goal-based architectural style can support the autonomy and adaptability required of sensor networks. Thus, the remaining part of this thesis will explore the question;
“Can a goal-based architectural style support the autonomy and adaptability required of sensor networks?”
48
Chen, Chih-Jung, and 陳志榮. "Developing an Embedded IPv6 Networking Stack for Wireless Sensor Network." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/24657309724763821846.
Full textAbstract:
碩士國立中央大學
資訊工程學系在職專班
101
The integration of Cloud Computing and Internet of Things is considered an important trend and industry in the future. IPv6 protocol is playing a key role in the development. There are a lot of IPv6 solutions presented to fulfill either a specific application or a hardware specification. Therefore, all of them are limited at a variety of heterogeneous network interconnections, low-power consumption and low-cost networking applications. We present an embedded IPv6 networking protocol stack which is based on Contiki uIPv6 and improves the functionality of uIPv6. We separate uIPv6 from Contiki OS in order to reduce the demand of the system resources, like the memory capacity. We also design our own IPv6 packet header compression / decompression mechanisms and the pseudo MAC address header in order to improve the scalability and the network connectivity of low-cost devices. Finally, we achieve the hardware-independent IPv6 networking stack. We also reduce the requirement of the frame payload length of the physical layer to improve the portability of IPv6 networking stack and accelerate the development of a variety of low-cost networking embedded systems. Our experiments show that the low-cost wireless sensor node and the gateway based on 2.4G RF successfully perform the improved uIPv6 networking stack in the absence of Contiki OS assistance. The wireless sensor node and the gateway can perform the IPv6 address configuration, ICMPv6 / UDP, the related network management mechanisms, the packet header compression / decompression mechanisms and the pseudo MAC address processing. The wireless sensor node, the gateway and the remote data collection center can effectively communicate each other via IPv6/ICMPv6/UDP. The research results will provide the rapid development of low-cost embedded IPv6 networking equipment, and accelerate the development of Internet of Things.
49
(9833915), G. Shafiullah. "Application of wireless sensor networking techniques for train health monitoring." Thesis, 2009. https://figshare.com/articles/thesis/Application_of_wireless_sensor_networking_techniques_for_train_health_monitoring/20380206.
Full textAbstract:
The use of wireless sensor networking in conjunction with modern machine learning tech- niques is a growing area of interest in the development of vehicle health monitoring (VHM) system. This VHM system informs forward -looking decision making and the initiation of suitable actions to prevent any future disastrous events. The main objective of this thesis is to investigate the design and possible deployment of a less expensive, low-power VHM system for railway operations.
The performance of rail vehicles running on railway tracks is governed by the dynamic behaviours of railway bogies, especially in the cases of lateral instability and track irregular- ities. The proposed VHM system measures and interprets vertical accelerations of railway wagons attached to a moving locomotive using a wireless sensor network (WSN) and ma- chine learning techniques to monitor lateral instability and track irregularities. Therefore this system enables reduction of maintenance and inspection requirements of railway systems while preserving the necessary high levels of safety and reliability.
The thesis is divided into three major sections. First, an energy -efficient data commu- nication system is proposed for railway applications using WSN technology. Initially, a conceptual design of sensor nodes with appropriate hardware design is presented. Then an energy -efficient adaptive time division multiple access (TDMA) protocol is developed, further reducing the power consumption of the data communication system. This data communication system collects data from sensor nodes on the wagons and passes it to the locomotive. Secondly, a data acquisition model involving machine learning techniques is used to further reduce power consumption, computational load and hardware cost of the overall condition monitoring system. Only three sensor nodes are required on each railway wagon body to collect sufficient data to develop a VHM system instead of four sensor nodes in an existing system. Finally, a VHM system is developed to interpret the vertical acceler- ation behaviour of railway wagons using popular regression algorithms that predicts typical dynamic behaviour of railway wagons due to track irregularities and lateral instability.
To summarise, this study introduces wireless sensor networking technology that enables the development of an energy-efficient, reliable and low cost data communication system for railway operational applications. By using machine learning techniques, an energy -efficient VHM system is developed which can be used to continuously monitor railway systems, particularly railway track irregularities and derailment potential with integrity. A major benefit of the developed system is a reduction in maintenance and inspection requirements of railway systems.
50
Shu, Yu-Yuan, and 許酉遠. "A Convex Hull-Based Localization Scheme for Irregular Wireless Sensor Networking Characteristics." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/91882893361546267153.
Full textAbstract:
碩士國立雲林科技大學
電機工程系碩士班
97
Wireless Sensor Network applications have gained more and more attention from the research community. In many applications like environmental monitoring, event detection, route discovery, disaster relief, and objects tracking, location information is both necessary and essential. Central to these applications is a requirement that sensor nodes should be located accurately and efficiently. As far as localization is concerned, considerable literature has assumed the circular coverage area of each wireless sensor node. This assumption, however, is untenable in most cases, because wireless signals are generally subject to physical constraints of propagation path loss and reflection, diffraction, refraction, and scattering of electromagnetic waves. As a consequence, radio signals become irregular, making position assessment liable to significant errors or inaccurate processing. As a remedy, this thesis exploits a mobile anchor node to assist in determining the position of wireless sensor nodes. Unlike other studies restricting the mobile anchor to move rectilinearly, we allow for a pragmatic situation where the mobile anchor can move flexibly to avoid obstacles in course of carrying out the localization process. Accordingly, this thesis provides a means to locate sensor nodes in a variety of non-idealized outdoor spaces containing obstacles. Our scheme distinguishes itself from previous studies in that it operates without reliance upon any baseline measurements about angle, distance, and received signal strength indication between radio transceivers. Our scheme is inspired from the convex hull algorithm to deal with radio signal irregularity that causes localization errors. Thus, our scheme takes on salient capabilities of performing localization in adverse circumstance. Apart from qualitative comparisons with other well known approaches, simulations have been conducted to provide quantitative comparisons among subject schemes as well. Performance results indicate that our proposal is cost effective in sense of maintaining high localization accuracy throughout, yet at the expense of insignificant overhead. Overall performance evaluation concludes that the proposed scheme can get fielded promisingly in practice.