在耐延遲網路(Delay Tolerant Network)中，因為節點具有移動性，因此找不到穩定且持續的點對點資料傳送路徑。常見的路由協定可分為機會路由、基於預測的路由以及調度路由，然而這些路由協定使用在市區環境中，有著些許不足與不適用，因此本論文提出一個適用在市區資料傳送的演算法。 本論文提出之混合階層式路由演算法，是在市區環境中建立一個以公車為基礎的資料傳送架構，包含行人與公車兩種節點。我們建立節點與節點相遇時資料交換傳送規則，例如行人與行人相遇、行人與公車相遇或是公車與公車相遇時各自有不同的資料傳送判斷與限制。 實驗結果也證明所提出之混合階層式演算法，除了可以有效地減少傳送延遲時間並提高訊息傳送成功率，並且在給定節點一定的移動速度與緩衝區大小下，我們的演算法有著最突出的效能。 / In Delay Tolerant Networks (DTNs), there is no guarantee that a stable connected path between source and destination nodes always exists because of high node mobility. The current DTN routing protocols can be summarized into three categories: opportunistic, prediction-based and scheduling protocols. However, these routing protocols have some deficiencies and are not specifically focused on the urban areas which have primarily two hierarchical nodes, namely pedestrian and bus nodes. We proposed a Hybrid Hierarchy Routing Protocol, a bus-based architecture for urban areas. We established the rules of data transmission when one node contacts other nodes. More specifically, Ped-to-Ped, Ped-to-Bus and Bus-to-Bus contacts, have different judgments and restrictions for data forwarding. The simulation results demonstrate that the Hybrid Hierarchy Routing Protocol can effectively reduce the delivery delay and improve the successful delivery rate. And in given certain speed and buffer sizes, our algorithm has the most prominent performance.

<p>A <i>wireless ad hoc network </i>consists of a number of mobile nodes that temporarily form a dynamic infrastructure-less network. New routing protocols that can adapt to the frequent topology changes induced by node mobility and varying link qualities are needed. During the last decade dozens of different ad hoc routing protocols have been proposed, optimized and partially compared, mainly through simulation studies.</p><p>This thesis takes an experimental approach to the evaluation of ad hoc routing protocols. We argue that real world experiments are needed in order to complement simulation studies, and to gain practical experience and insights that can provide feedback to routing protocol design and existing simulation models. For example, we discovered a performance discrepancy for the AODV protocol between real world experiments and corresponding simulation studies. This so called ``communication gray zone'' problem was explored and countermeasures were implemented. As a result we could eliminate this performance problem to a large extent. </p><p>We have implemented a software-based testbed called APE to carry out efficient and systematic experimental evaluation of ad hoc routing protocols. Experiments with up to 37 participating ad hoc nodes have demonstrated APE's ability to scale efficiently and assess repeatability between test runs. APE is part of our methodology for test repeatability in a real world ad hoc routing protocol testbed. It addresses the repeatability issue induced by stochastic factors like the radio environment and node mobility. Using APE, we have performed a systematic experimental evaluation of three ad hoc routing protocols (AODV, OLSR and LUNAR). Our results show that TCP does not work satisfactorily even in very small networks with limited mobility.</p>

為了降低無線網路基地台後端之backhaul成本及解決Ad hoc網路涵蓋面積問題，無線網狀網路WMNs(Wireless Mesh Networks)因此應運而生。WMNs網路上的節點裝置與Ad hoc網路上的行動裝置對電量消耗及負載的需求是非常不同的，所以在Ad hoc網路上可使用之路由協定在WMNs網路上是無法直接適用的。 在Pure Ad hoc網路上考量Power之MMBCR(Min-Max Battery Cost Routing)及考量Loading之CSLAR(Contention Sensitive Load Aware Routing)等路由協定並沒有考量到WMNs網路上不同元件間的不同特性。有鑑於此，我們著重在Hybrid WMNs網路環境上，並提出了在Mesh Clients及Routers上同時考量Power及Loading的路徑演算法，我們稱之為POLAR。實驗結果顯示我們的路由協定能夠提昇整體的網路效能及延長網路存活時間。 / In order to reduce the backhaul cost and solve Ad hoc network coverage problem, WMNs (Wireless Mesh Networks) arise at the historic moment. The requirements on power efficiency and loading are much different between mesh nodes of WMNs and mobile hosts of ad hoc networks. The routing protocol used in Ad hoc networks would be not suitable in WMN networks. The power-aware routing in MMBCR (Min-Max Battery Cost Routing) and load-aware routing in CSLAR (Contention Sensitive Load Aware Routing) used in pure Ad hoc networks don‘t consider the different characteristics of the components in WMNs. In view of this, we focus on the Hybrid WMNs environment, and propose a combined POwer-Aware with Load-Aware Routing algorithm (Called POLAR) along mesh clients and routers. The experimental results show that our routing protocol can enhance the network efficiency and lengthen the network live time.

Este trabalho propõe estratégias de roteamento e de controle de acesso ao meio destinadas as redes urbanas, motivadas pelo monitoramento e controle de variáveis elétricas relacionadas à iluminação pública. Tais estratégias foram desenvolvidas segundo requisitos da aplicação, trabalhos encontrados na literatura, limitações do protocolo IEEE 802.15.4 e as especificações RFC 5548 e IEEE 802.15.4e (draft). As estratégias desenvolvidas foram incorporadas a protocolos encontrados na literatura, as quais geraram protocolos aperfeiçoados para redes urbanas, dentre eles GGPSR e gradiente em função da maior distância, utilizados para o tráfego divergente e convergente, respectivamente. O protocolo GGPSR é composto pelo algoritmo geográfico GPSR, geocast e retransmissões para os vizinhos seguindo o critério do GGPSR em caso de falha. O protocolo baseado na maior distância é composto pelo algoritmo do gradiente, o qual utiliza a maior distância no caso de receptores com pesos de gradiente iguais e retransmissões seguindo o mesmo critério. Foi utilizado um modelo de propagação realista, no qual foi aplicada a estratégia de mapeamento de vizinhos dos nós de acordo com a distância aproximada fornecida pelo atributo do pacote RSSI. Além disso, para ambos os tipos de tráfego, foi aplicado o mecanismo de controle de acesso ao meio RIT com o objetivo de minimizar o consumo energético. A avaliação dos protocolos gerados a partir dessas estratégias foi feita em simulação utilizando a ferramenta NS-2 integrada em cenários de grande escala fornecidos pela concessionária de iluminação pública Elektro, segundo os critérios de energia remascente da rede, média de atraso fim a fim e taxa de entrega fim a fim. Os resultados obtidos mostram que os protocolos gerados superam protocolos propostos na literatura; além disso, a estratégia baseada na distância obtida pelo atributo RSSI viabiliza a aplicação do protocolo GGPSR. Em relação à aplicação do RIT com a estratégia de parâmetros em função do gradiente, esta se mostrou mais eficiente em comparação com os parâmetros de RIT iguais para todos os nós. / This work proposes routing and medium access control strategies for urban networks, particularly related to monitoring and control of electric variables in the street lighting system. Such strategies were developed according to application requirements, studies in the literature, limitations of the IEEE 802.15.4 protocol, and RFC 5548 and IEEE 802.15.4e (draft) specifications. Strategies were incorporated into protocols found in the literature, which generated specific improved protocols for urban networks, including GGPSR and Gradient based on the farthest neighbor, applied to divergent and convergent traffic, respectively. The GGPSR protocol is composed by the GPSR algorithm, geocast and retransmissions to neighbors according to the GGPSR criterion when a failure occurs. The protocol based on the longest distance comprises the gradient algorithm, which considers the longest distance when receivers have equal gradient weights and retransmissions follow the same criterion. A realistic propagation model was used, implementing the strategy to map neighboring nodes according to the approximate distance provided by the RSSI packet attribute. Moreover, for both traffic ypes, the RIT medium access control mechanism was used in order to minimize energy consumption. Protocols generated by these strategies were evaluated through simulation in NS-2 tool applied to large scale scenarios provided by public street lighting concessionaire Elektro, according to the criteria of remaining energy network, end-to-end average delay and end-to-end delivery rate. Results show that the generated protocols outperform protocols proposed in the literature; in addition, the strategy based on the distance obtained by the RSSI attribute enables the use of the GGPSR protocol. Regarding the use of RIT considering the parameters as a function of the gradient, this strategy is more efficient compared to using the same RIT parameters for all nodes.

L'efficacité énergétique constitue l'objectif clef pour la conception des protocoles de communication pour des réseaux de capteurs radio multi-sauts. Beaucoup d'efforts ont été réalisés à différents niveaux de la pile protocolaire à travers des algorithmes d'agrégation spatiale et temporelle des données, des protocoles de routage efficaces en énergie, et des couches d'accès au médium avec des mécanismes d'ordonnancement permettant de mettre la radio en état d'endormissement afin d'économiser l'énergie. Pour autant, ces protocoles utilisent de façon importante des paquets de contrôle et de découverte du voisinage qui sont coûteux en énergie. En outre, cela se fait très souvent sans aucune interaction entre les différentes couches de la pile. Ces travaux de thèse s'intéressent donc particulièrement à la problématique de l'énergie des réseaux de capteurs à travers des protocoles de routage et d'accès au médium. Les contributions de cette thèse se résument de la manière suivante : Nous nous sommes tout d'abord intéressés à la problématique de l'énergie au niveau routage. Dans cette partie, les contributions se subdivisent en deux parties. Dans un premier temps, nous avons proposé une analyse théorique de la consommation d'énergie des protocoles de routage des réseaux radio multi-sauts d'appréhender au mieux les avantages et les inconvénients des uns et des autres en présence des modèles de trafic variables, un diamètre du réseau variable également et un modèle radio qui permet de modéliser les erreurs de réception des paquets. À l'issue de cette première étude, nous sommes parvenus à la conclusion que pour être économe en énergie, un protocole de routage doit avoir des approches similaires à celle des protocoles de routage géographique sans message hello. Puis, dans un second temps, nous introduisons une étude de l'influence des stratégies de relayage dans un voisinage à 1 saut sur les métriques de performance comme le taux de livraison, le nombre de messages dupliqués et la consommation d'énergie. Cette étude est suivie par une première proposition de protocole de routage géographique sans message hello (Pizza-Forwarding (PF)) exploitant des zones de relayage optimisées et sans aucune hypothèse sur les propriétés du canal radio. Dans le but de réduire considérablement la consommation de PF, nous proposons de le combiner avec une adaptation d'un protocole MAC asynchrone efficace en énergie à travers une approche transversale. La combinaison de ces deux approches montre un gain significatif en terme d'économie d'énergie avec des très bon taux de livraison et cela quels que soient les scénarios et la nature de la topologique. / Energy-efficient communication protocol is a primary design goal for Wireless Sensor Networks (WSNs). Many efforts have been done to save energy anywhere in the protocol stack through temporal and spatial data aggregation schemes, energy-aware routing protocols, activity scheduling and energy-efficient MAC protocols with duty cycle. However both control packets and beacons remain which induces a huge waste energy. Moreover, their design follows the classical layered approach with the principle of modularity in system development, which can lead to a poor performance in WSNs. This thesis focuses on the issues of energy in WSNs through energy-efficient routing and medium access control protocols. The constributions of this thesis can be summarized as follows: First, we are interested on the energy issues at the routing layer for multihop wireless sensor networks (WSNs). We propose a mathematical framework to model and analyze the energy consumption of routing protocols in multihop WSNs by taking into account the protocol parameters, the traffic pattern and the network characteristics defined by the medium channel properties, the dynamic topology behavior, the network diameter and the node density. In this study, we show that Beacon-less routing protocol should be a best candidate to save energy in WSNs. We investigate the performance of some existing relay selection schemes which are used by Beacon-less routing protocols. Extensive simulations are proposed to evaluate their performance locally in terms of packet delivery ratio, duplicated packet and delay. Then, we extend the work in multihop wiriless networks and develop an optimal solution, Enhanced Nearest Forwarding within Radius, which tries to minimize the per-hop expected number of retranmissions in order to save energy. We present a new beaconless routing protocol called Pizza-Forwarding (PF) without any assumption on the radio environment: neither the radio range nor symmetric radio links nor radio properties (shadowing, etc.) are assumed or restricted. A classical greedy mode is proposed. To overcome the hole problem, packets are forwarded to an optimal node in the two hop neighbor following a reactive and optimized neighborhood discovery. In order to save energy due to idle listening and overhearing, we propose to combine PF's main concepts with an energy-efficient MAC protocol to provide a joint MAC/routing protocol suitable for a real radio environment. Performance results lead to conclude to the powerful behavior of PFMAC.

No description available.

Rychlý vývoj v oblasti mobilní informatiky vyústil v nový, alternativní způsob mobilní komunikace, v němž mobilní uzly tvoří samoorganizující se bezdrátovou síť, jíž se říká mobilní síť ad hoc (Mobile Ad hoc Network, MANET). Specifické vlastnosti sítí MANET stavějí návrh síťového protokolu před řadu problémů na všech vrstvách protokolové sady . Příčinou jsou nepředvídatelné změny topologie a mobilní povaha těchto sítí. Nástrojem, který řeší problémy plynoucí z mobility uzlů, je predikce budoucích změn v topologii sítě. To má zásadní význam pro různé úlohy jako přesměrování. Tato disertační práce se zabývá dvěma metodami predikce mobility pro sítě MANET. První metoda se nazývá „predikce mobility s využitím virtuální mapy“ (mobility prediction using virtual map) a předpokládá, že každý uzel si dokáže vybudovat svou virtuální mapu v závislosti na svém umístění v průběhu času. Vyvinutý predikční algoritmus byl implementován do síťového simulátoru NS-2, aby jej bylo možné vyhodnotit. V této práci zkoumám stávající modely mobility a způsob, jakým v nich lze aplikovat tuto metodu predikce. Simulace sledují zlepšení výkonnosti, co se týče průměrného zpoždění na bázi end-to-end, poměru doručených paketů a propustnosti sítě. Navržený koncept predikce byl implementován pomocí směrovacího protokolu AODV(Ad Hoc On-Demand Distance Vector). Pro druhou metodu jsem vyvinula umělou neuronovou síť pro predikci pohybů v sítích MANET. Model pro predikci mobility vznikl na základě dat shromážděných ze vzorců umístění. K učení či trénování ANN byl využit bayesovský přístup. Ten byl implementován v softwaru pro trénování bayesovských neuronových sítí s názvem Model Manager. Nejlepším způsobem hodnocení závěrečného modelu je provedení predikcí a jejich srovnání s cílovými daty. Predikce vznikají na základě 50 vzorců jako vstupních proměnných. Dosažené výsledky prezentované s diskutované v práci se vyznačují zlepšením zásadních parametrů komunikační sítě, jako jsou propustnost, zpoždění, Poměr doručených paketů, až o 30% v porovnání s klasickým směrovacím protokolem AODV, kde není implementován predikční model.

Wireless sensor networks is a broad subject with many applications and interesting research areas, such as optimization within connectivity and energy efficiency. One problem is that most published articles in this field use customized simulation environments and do not provide source code of their implementation. By not including aspects of implementation, it becomes difficult to determine how the results are achieved, which questions the validity and reliability of the works. This thesis aims to reproduce one of these researched methods, an algorithm that balances battery life with efficient routing within a network using fuzzy logic, with the goal to increase the reliability of the methodology within its field. The research question constructed on the foundation of these premises is thus “Is reproducibility satisfactory in a research work on a multi-objective routing algorithm, using fuzzy logic, in wireless sensor networks?, a case study by Minhas et al”. Two additional research questions emerge from the first one: “How does the reproduced algorithm perform in comparison to a selection of dif erent routing algorithms?” and “Is the reproduced algorithm, as is, applicable to a less idealistic environment?” To answer the research questions a computer simulation method is used to build, execute, and analyze the output of the algorithms. The results show that the implemented algorithm performs noticeably better in both lifetime and ratio to the shortest path compared with the original implementation, hinting towards the implementation and reproducibility deviating from expected results. The reproduced algorithm is also compared to two other algorithms under a different simulation environment, where it performs better in lifetime and packet delivery rate whilst performing slightly worse in energy efficiency and total energy consumption. Due to the significant differences in performance against the reproduced article’s implementation the study concludes that the reproducibility is not satisfactory. Lastly, it concludes that it does not perform well in a less idealistic simulation environment, making it less applicable.

[ES] La industria se encuentra inmersa de pleno en la cuarta revolución industrial, y es gracias a la capacidad de digitalización y de procesamiento de grandes cantidades de datos, que se consigue mejorar y optimizar el rendimiento de los sistemas industriales actuales. Son muchos los paradigmas y conceptos que están dando forma a lo que se conoce como Industria 4.0, y uno de ellos ha sido el Internet de las Cosas (IoT: Internet of Things) o más concretamente el Internet Industrial de las Cosas (IIoT: Industrial Internet of Things), como se ha llamado al subconjunto con determinados requisitos orientados al sector industrial. Las redes de sensores inalámbricos (WSN: Wireless Sensor Networks) son tecnologías habilitadoras para estos sistemas IoT, ya que gracias a su fácil escalabilidad ofrecen gran capacidad de sensorización con un coste energético reducido. En el ámbito industrial, estas redes de sensores deben cumplir con requisitos estrictos de fiabilidad, y su aceptación está siendo lenta debido a que su robustez y facilidad de configuración no han podido rivalizar con las tecnologías clásicas. Con el desarrollo de esta tesis, se pretende hacer frente a determinados aspectos de mejora de las redes industriales de sensores inalámbricos. Para ello, se diseñan nuevos mecanismos para la sincronización, evaluando metodologías alternativas de enrutamiento y proponiendo modelos analíticos que permitan caracterizar fielmente el proceso de despliegue de estas redes, con el objetivo de cubrir aquellas lagunas que dejan los estándares y protocolos bajo estudio. Los mecanismos propuestos por el estándar IEEE 802.15.4e, en concreto el método de acceso al medio mediante TSCH (Time-Slotted Channel Hopping), presentan las bases sobre las que construir una red WSN fiable y robusta, y mediante los desarrollos propuestos en esta tesis se facilita su implantación en sistemas de Industria 4.0. / [CA] La indústria es troba de ple en la quarta revolució industrial, i és gràcies a la capacitat de digitalització i de processament de grans quantitats de dades, que s'aconsegueix millorar i optimitzar el rendiment dels sistemes industrials actuals. Són moltes els paradigmes i conceptes que estan donant forma al que es coneix com a Indústria 4.0, i una d'elles ha sigut la Internet de les Coses (IoT: Internet of Things) o més concretament la Internet Industrial de les Coses (IIoT: Industrial Internet of Things), com s'ha anomenat al subconjunt amb determinats requisits orientats al sector industrial. Les xarxes de sensors sense fils (WSN: Wireless Sensor Networks) són tecnologies habilitadores per a sistemes IoT, ja que gràcies a la seua fàcil escalabilitat ofereixen gran capacitat de digitalització amb un cost energètic reduït. En l'àmbit industrial, aquestes xarxes de sensors han de complir amb requisits estrictes, i la seua acceptació està sent lenta a causa de factors que fan que aquests sistemes no substituïsquen a les tecnologies clàssiques. Amb el desenvolupament d'aquesta tesi, es pretén fer front a determinats aspectes de millora de les xarxes industrials de sensors sense fils. Per a això, es dissenyen nous mecanismes per a la sincronització, avaluant metodologies alternatives d'encaminament i proposant models analítics que permeten caracteritzar fidelment el procés de desplegament d'aquestes xarxes, amb l'objectiu de cobrir aquelles llacunes que deixa l'estàndard. Els mecanismes proposats per l'estàndard IEEE 802.15.4, en concret el mètode d'accés al mitjà TSCH, presenten les bases sobre les quals construir una xarxa WSN fiable i robusta, i mitjançant els desenvolupaments proposats en aquesta tesi es facilita la seua implantació en sistemes d'Indústria 4.0. / [EN] The industry is fully engaged in the fourth industrial revolution. Due to digital transformation and the processing of large amounts of data, it is possible to improve the value chain and provide a real-time optimization for the current industrial systems. There are many paradigms and concepts that that fall under the umbrella of Industry 4.0, and one of them is the Internet of Things (IoT) or more specifically the Industrial Internet of Things (IIoT), as the subset with certain industry-oriented requirements is known. Wireless Sensor Networks (WSN) are an enabling technology for IoT systems, since its easy scalability offers a great sensorization capacity with a reduced energy cost. In the industrial field, these sensor networks must meet strict reliability requirements, so growth in the industrial market is slow as these systems fail to replace legacy technologies. This thesis addresses different aspects of improving industrial wireless sensor networks. To that end, new mechanisms for synchronization have been designed, evaluating alternative routing methodologies and proposing analytical models that allow a comprehensive characterization of the deployment process of these networks, aiming of covering those gaps left by the standard. The mechanisms proposed by the IEEE 802.15.4 standard, specifically the medium access control method Time-Slotted Channel Hopping (TSCH), present the bases to deploy a reliable and robust WSN network, and through the developments proposed in the thesis, it is possible smooth the way for its implementation in Industry 4.0 systems. / Vera Pérez, J. (2021). Diseño y evaluación de mecanismos de optimización en redes de sensores inalámbricas industriales [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/179700

<p>One of the most parts of VOIP management is fault management and, in having a good fault management, finding good mechanisms to detect faults in the network have to be considered.</p><p>The main focus of this project is to implement different types of fast fault recovery protocols in networks<strong>,</strong> especially networks that carry IP telephony. Having a complete understanding of some common link failure detection and fault recovery protocols<strong>,</strong> such as spanning tree protocol (STP), rapid spanning tree protocol (RSTP) and per-VLAN spanning tree protocol (PVSTP)<strong>,</strong> and also having a complete understanding of three other common techniques for fault detection and fault recovery, such as hot standby routing protocol (HSRP), virtual router redundancy protocol (VRRP) and gateway load balancing protocol (GLBP) will be regarded in the project. We are going to test some fault recovery protocols which can be used in IP telephony networks and choose the best. We intend to focus on this issue in LAN environment in theoretical descriptions and practical implementations.</p><p>The final outcome of the thesis is implementation in the Halmstad University’s lab environment to obtain the final result. For doing our thesis, we are going to use some technical tools as hardware tools (Cisco L3 and L2 switches, Routers, IP Phones) and tools which are used for network performance monitoring<strong>,</strong> like as CommVeiw.</p>