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GHUMMAN, SHAKEEL AHMAD. "Security in Wireless Mesh Network." Thesis, Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-4175.
Повний текст джерелаАнотація:
The Master’s thesis report describes the wireless mesh networks functions,
characteristics, network management and finally different protocols with security issues and applications. Wireless Networks (WMNs) are replacing wireless Infrastructure networks in many areas because of their lower and higher flexibility. The wireless mesh networks (WMNs) provides network access for both mesh and conventional clients through mesh routers and mesh clients. Communication across the network is formed via the bridge functions. Mesh router also provides the minimal mobility and form the backbone of WMNs.
Wireless mesh network has resolved the limitation of ad hoc networks which is ultimately improves the performance of Ad hoc networks. Security is a very important issue which can be resolve through proper management of network. The improvment of 802.11i security has greatly improved the network perfomance and increase the encryption and integrity security capabilities. The key points which are being addressed in this report are security issues and threats and their counter measures. Attacks which can come on diffent layers are being discussed in this survey. Security of wireless mesh network is still under consideration. Wireless mesh network are attracting more attention due to its enhanced features.
Wireless mesh network topology technology is being discussed in this report. Then network management of WMNs is explained and in the concluding chapters security issues are discussed. Threats, attacks and challenges of WMNs are discussed in this survey.
2
Amusa, Ebenezer Olukayode. "An enhanced cross-layer routing protocol for wireless mesh networks based on received signal strength." Thesis, University of Bedfordshire, 2010. http://hdl.handle.net/10547/143534.
Повний текст джерелаАнотація:
The research work presents an enhanced cross-layer routing solution for Wireless Mesh Networks (WMN) based on Received Signal Strength. WMN is an emerging technology with varied applications due to inherent advantages ranging from self-organisation to auto-con guration. Routing in WMN is fundamen- tally achieved by hop counts which have been proven to be de cient in terms of network performance. The realistic need to enhance the link quality metric to improve network performance has been a growing concern in recent times. The cross-Layer routing approach is one of the identi ed methods of improving routing process in Wireless technology. This work presents an RSSI-aware routing metric implemented on Optimized Link-State Routing (OLSR) for WMN. The embedded Received Signal Strength Information (RSSI) from the mesh nodes on the network is extracted, processed, transformed and incorporated into the routing process. This is to estimate efficiently the link quality for network path selections to improved network performance. The measured RSSI data is filtered by an Exponentially Weighted Moving Average (EWMA) filter. This novel routing metric method is called RSSI-aware ETT (rETT). The performance of rETT is then optimised and the results compared with the fundamental hop count metric and the link quality metric by Expected Transmission Counts (ETX). The results reveal some characteristics of RSSI samples and link conditions through the analysis of the statistical data. The divergence or variability of the samples is a function of interference and multi-path e effect on the link. The implementation results show that the routing metric with rETT is more intelligent at choosing better network paths for the packets than hop count and ETX estimations. rETT improvement on network throughput is more than double (120%) compared to hop counts and 21% improvement compared to ETX. Also, an improvement of 33% was achieved in network delay compared to hop counts and 28% better than ETX. This work brings another perspective into link-quality metric solutions for WMN by using RSSI to drive the metric of the wireless routing protocol. It was carried out on test-beds and the results obtained are more realistic and practical. The proposed metric has shown improvement in performance over the classical hop counts metric and ETX link quality metric.
3
Zhang, Xiaowen. "Resource Management and Optimization in Wireless Mesh Networks." FIU Digital Commons, 2009. http://digitalcommons.fiu.edu/etd/173.
Повний текст джерелаАнотація:
A wireless mesh network is a mesh network implemented over a wireless network system such as wireless LANs. Wireless Mesh Networks(WMNs) are promising for numerous applications such as broadband home networking, enterprise networking, transportation systems, health and medical systems, security surveillance systems, etc. Therefore, it has received considerable attention from both industrial and academic researchers. This dissertation explores schemes for resource management and optimization in WMNs by means of network routing and network coding. In this dissertation, we propose three optimization schemes. (1) First, a triple-tier optimization scheme is proposed for load balancing objective. The first tier mechanism achieves long-term routing optimization, and the second tier mechanism, using the optimization results obtained from the first tier mechanism, performs the short-term adaptation to deal with the impact of dynamic channel conditions. A greedy sub-channel allocation algorithm is developed as the third tier optimization scheme to further reduce the congestion level in the network. We conduct thorough theoretical analysis to show the correctness of our design and give the properties of our scheme. (2) Then, a Relay-Aided Network Coding scheme called RANC is proposed to improve the performance gain of network coding by exploiting the physical layer multi-rate capability in WMNs. We conduct rigorous analysis to find the design principles and study the tradeoff in the performance gain of RANC. Based on the analytical results, we provide a practical solution by decomposing the original design problem into two sub-problems, flow partition problem and scheduling problem. (3) Lastly, a joint optimization scheme of the routing in the network layer and network coding-aware scheduling in the MAC layer is introduced. We formulate the network optimization problem and exploit the structure of the problem via dual decomposition. We find that the original problem is composed of two problems, routing problem in the network layer and scheduling problem in the MAC layer. These two sub-problems are coupled through the link capacities. We solve the routing problem by two different adaptive routing algorithms. We then provide a distributed coding-aware scheduling algorithm. According to corresponding experiment results, the proposed schemes can significantly improve network performance.
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Qi, Bing Biaz Saad. "Routing metrics for multi-hop wireless MESH networks." Auburn, Ala., 2009. http://hdl.handle.net/10415/1705.
Повний текст джерела
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Mhlanga, Martin Mafan. "Towards the design of an energy-aware path selection metric for IEEE 802.11s wireless mesh network." Thesis, University of Zululand, 2012. http://hdl.handle.net/10530/1058.
Повний текст джерелаАнотація:
Submitted in accordance with the requirements for the degree of Master of Arts in Communication Science at the University of Zululand, South Africa, 2012.It is everyone’s dream to have network connectivity all the time. This dream can only be realised provided there are feasible solutions that are put in place for the next generation of wireless works. Wireless Mesh Networking (WMN) is therefore seen as a solution to the next generation of wireless networks because of the fact that WMNs configures itself and it is also self healing. A new standard for WMNs called the IEEE 802.11s is still under development. The protocol that is used by the IEEE 802.11s for routing is called Hybrid Wireless Mesh Protocol (HWMP). The main purpose of HWMP is to perform routing at layer-2 of the OSI model also referred to as the data link layer (DLL). Layer-2 routing is also referred to as the mesh path selection and forwarding. Devices that are compliant to the IEEE 802.11s standard will be able to use this path selection protocol. Devices that are manufactured by different vendors will therefore be interoperable. Even though significant efforts have gone into improving the performance of HWMP, the protocol still faces a lot of limitations and the most limiting factor is the small or restricted energy of the batteries in a wireless network. This is because of the assumption that mesh nodes that are deployed in urban areas tend to have no energy constraints while WMN nodes deployed in rural faces serious energy challenges. The latter relies on batteries and not on electricity supply which powers the WMN nodes in urban areas. This work, therefore, explores further the current trends towards maximising the network lifetime for the energy constrained networks. Hence the goal of this study is to design a path selection algorithm that is energyaware and optimising for the IEEE 802.11s based HWMP. The main idea is that paths with enough energy for transmission must be selected when transmitting packets in the network. Therefore, a simulation using NS-2 was carried out to assess the network performance of the proposed EAPM metric with the other metrics that have been analysed in literature including ETX. ETX has been used in WMNs but was not developed specifically for mesh. In conclusion, EAPM conserves more energy than the Multimetric, airtime link metric and lastly ETX. The simulation experiments show that EAPM optimises the energy used in the network and as a result EAPM has a prolonged network lifespan when comparing it to the rest of the metrics evaluated in this study. The results also revealed that the newly proposed EAPM exhibits superior performance characteristics even with regard to issues like end-to-end delay and packet delivery ratio.
CSIR Meraka Institute
6
Gaur, Amit. "Secured Communication in Wireless Sensor Network (WSN) and Authentic Associations in Wireless Mesh Networks." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1282053086.
Повний текст джерела
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Kobo, Hlabishi. "Situation-aware routing for wireless mesh networks with mobile nodes." Thesis, University of the Western Cape, 2012. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_6647_1370594682.
Повний текст джерела
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Abdalla, Taha. "Scalable Wireless Mesh Networks." University of the Western Cape, 2016. http://hdl.handle.net/11394/5868.
Повний текст джерелаАнотація:
Magister Scientiae - MSc (Computer Science)Wireless Mesh Networks (WMNs) are wireless multi-hop networks built on wireless nodes that operate in an Independent Basic Set Identifier (IBSS) mode of the IEEE 208.11 wireless standard. IBSS is well known as an ad hoc mode which is found to build ad hoc wireless networks with the aid of routing protocols crafted to work in this mode. Ad hoc wireless mesh networks are always described as self-healing, self-configuring, easy to build, etc. However, these features do come at a cost because a WMN suffers performance degradation and scalability issues, which mainly come from the underlying IBSS mode that is used to form the physical network. Furthermore this is exacerbated by routing protocols in the upper layers which are intended to form a flat network architecture. Partitioning or clustering the flat network into smaller units has been proven to be a viable mechanism to counter the scalability problem in the communication network. The wired network for instance, presents a segmented, hierarchical architecture, where end user devices are organized in virtual local area networks (VLANs) using Ethernet switches and then Routers aggregate multiple VLANs. This thesis develops and evaluates a heterogeneous, clustering architecture to enhance WMN scalability and management. In the proposed architecture, the clustering is separated from the routing, where the clustering is done at the physical layer. At the routing level, each cluster is configured as a WMN using layer 2 routing for intra-cluster routing, and layer 3 routing for inter-domain routing between clusters. Prototypes for the proposed architecture have been built in a laboratory testbed. The proposed architecture reported better scalability and performance results compared to the traditional flat architecture.
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Simkhada, Shailendra, Christopher Lee, David Venderwerf, Miranda Tyree, and Tyler Lacey. "Wireless Sensor Network." International Foundation for Telemetering, 2011. http://hdl.handle.net/10150/595644.
Повний текст джерелаАнотація:
ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, NevadaThe scope of this document is the description of design and implementation of the wireless sensor network realized as a part of our Senior Design Capstone Project. The various components and sub-systems that comprise the final product are discussed, followed by the implementation procedures and results.
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Hu, Wenjun. "A tale of two prototypes : practical network coding for wireless mesh networks." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604695.
Повний текст джерелаАнотація:
Wireless mesh networks are seen as a cost effective way of providing connectivity for community networks, but their performance under existing approaches is unsatisfactory. In this thesis, we apply network coding, a recent technique from information theory, to wireless mesh networks to improve the network throughput. Various theoretical results have demonstrated the benefits of network coding in many scenarios, but there are few practical systems. In the light of this, we present the prototype design and implementation for two coding protocols, Opportunistic Coding (COPE) and Multipath Code Casting (MC²). The former applies to multiple simultaneous unicast sessions traversing a router, where the use of network coding increases the network capacity, and the latter is for coding within a single unicast flow between a source and destination pair, where coding waives the need for strong coordination between relays on different paths. Both prototypes have been deployed on indoor testbeds, and we study their performance in various traffic and channel conditions. To the best of our knowledge, the prototype for COPE was the first real-world implementation of network coding in a wireless environment, and there was only one other network coding system, for peer-to-peer networks, prior to that. The MC² design integrates multipath forwarding, rate control and error control into a unified framework. Our results show that network coding is a promising technique for the wireless mesh environment, even though challenges remain.
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Van, der Merwe Zuann Stephanus. "A network traffic model for wireless mesh networks / Z.S. van der Merwe." Thesis, North-West University, 2013. http://hdl.handle.net/10394/9229.
Повний текст джерелаАнотація:
Design and management decisions require an accurate prediction of the performance of the network. Network performance estimation techniques require accurate network traffic models. In this thesis we are concerned with the modelling of network traffic for the wireless mesh network (WMN) environment. Queueing theory has been used in the past to model the WMN environment and we found in this study that queueing theory was used in two main methods to model WMNs. The first method is to consider each node in the network in terms of the number of hops it is away from the gateway.
Each node is then considered as a queueing station and the parameters for the station is derived from the number of hops each node is away from the gateway. These topologies can be very limiting in terms of the number of physical topologies they can model due to the fact that their parameters are only dependent on the number of hop-counts each node is away from the gateway. The second method is to consider a fixed topology with no gateways. This method simplifies analysis but once again is very limiting.
In this dissertation we propose a queueing based network traffic model that uses a connection matrix to define the topology of the network. We then derive the parameters for our model from the connection matrix. The connection matrix allows us to model a wider variety of topologies without modifying our model. We verify our model by comparing results from our model to results from a discrete event simulator and we validate our model by comparing results from our model to results from models previously proposed by other authors. By comparing results from our model to results of other models we show that our model is indeed capable of modelling a wider variety of topologies.Thesis (MIng (Computer and Electronic Engineering))--North-West University, Potchefstroom Campus, 2013.
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Sravani, Kancharla. "Study on Energy saving in Wireless Mesh Networks Using Network Simulator - 3." Thesis, Blekinge Tekniska Högskola, Institutionen för kommunikationssystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-13344.
Повний текст джерелаАнотація:
Context: Wireless Mesh Network (WMN) is a form of ad-hoc network with flexible backhaul infrastructure and configuration, provides adaptive wireless internet connectivity to end users with high reliability. WMN is a wireless network consisting of mesh clients, mesh routers and gateways which are organized in a mesh topology with decentralized nature can consume more energy for data transmission. The networking performance of WMNs can be degraded due to the fact of high energy consumption for data transmission. Therefore, energy efficiency is the primary factor for attaining eminent performance. Organizing efficient routing and proper resource allocation can save huge amount of energy. Objectives: The main goal of this thesis is to reduce the energy consumption in WMNs. To do this, a new energy efficient routing algorithm is suggested. Adaptive rates based on rate allocation strategy and end to end delay metric are used mainly for optimal path selection in routing, which may in turn reduces the resource utilization and energy consumption. Method: An energy efficient routing algorithm is implemented by using the Ad hoc OnDemand Distance Vector (AODV) routing protocol. The RREQ packet in AODV is modified by adding a new field known as delay parameter which measures end to end delay between nodes. Adaptive rates obtained from Rate allocation policy are considered in the routing process to reduce energy consumption in the network. Energy measurement of the WMN and its performance is evaluated by measuring the metrics such as Throughput, End-to-End delay, Packet Delivery Ratio (PDR). For performing the simulation process, in this thesis, Network Simulator - 3 (NS-3) which is an open source discrete-event network simulator in which simulation models can be executed in C++ and Python is used. Using NetAnim-3.107 animator in NS-3-25.1, traffic flows between all the nodes are displayed. Results: The results are taken for existing algorithm and proposed algorithm for 25,50,75 and 100 nodes. Comparison of results shows that the total energy consumption is reduced for proposed algorithm for in all four scenarios. Conclusion: Energy efficient routing algorithm is implemented in different scenarios of radio access networks and energy is saved. Due to this algorithm even the performance metrics, Throughput, End-to-End delay, Packet Delivery Ratio (PDR) have shown eminent performance.
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Mudali, Pragasen. "Topology control for wireless mesh networks and its effect on network performance." Thesis, University of Zululand, 2017. http://hdl.handle.net/10530/1565.
Повний текст джерелаАнотація:
A thesis submitted to the Faculty of Science and Agriculture in fulfilment of the Degree of Doctor of Philosophy in the Department of Computer Science at the University of Zululand, 2017InfrastructureWireless Mesh Networks (I-WMNs) are increasingly used to provide network connectivity and Internet access to previously under-served areas in the developing world. It is common for some of these deployments to be battery-powered due to a lack of electrical infrastructure in the targeted areas. Thus, the energy-efficiency of these networks gains additional importance. Topology Control (TC) has been previously reported to improve the energy-efficiency and network performance of wireless ad-hoc networks, including I-WMNs. However,simulation-based studies have been relied upon to reach these conclusions and the study of TC prototypes applicable to I-WMNs has largely been limited to design issues. Thus, the study of the efficacy of TC prototypes as a mechanism for improving energy-fficiency and network performance remains an open issue. The thesis addresses this knowledge gap by studying the dynamic, run-time behaviours and the network topologies created by two standards-compatible TC prototypes. This study provides unique insight into how the prototypes consume computational resources, maintain network connectivity, produce cumulative transceiver power savings and affect the workings of the routing protocol being employed. This study also documents the topology instability caused by transceiver power oscillations produced by the PlainTC prototype. A context-based solution to reduce transceiver power oscillations and the subsequent topology instability is proposed. This solution applies the Principal Component Analysis statistical method to historical network data in order to derive the weights associated with each of the identified context variables. A threshold value is defined that only permits a node to adjust its transceiver power output if the observed change in a node’s context exceeds the threshold. The threshold mechanism is incorporated into the PlainTC+ prototype and is shown to reduce topology instability whilst improving network performance when compared to PlainTC.The results obtained in this study suggest that I-WMN topologies formed by TC are able to closely match the performance of networks that do not employ TC. However, this study shows that TC negatively affects the energy efficiency of the network despite achieving cumulative transceiver power savings.
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Kuo, Victor. "Enabling Parallel Wireless Communication in Mobile Robot Teams." Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/9410.
Повний текст джерелаАнотація:
Wireless inter-robot communication enables robot teams to cooperatively solve complex problems that cannot be addressed by a single robot. Applications for cooperative robot teams include search and rescue, exploration and surveillance. Communication is one of the most important components in future autonomous robot systems and is essential for core functions such as inter-robot coordination, neighbour discovery and cooperative control algorithms. In environments where communication infrastructure does not exist, decentralised multi-hop networks can be constructed using only the radios on-board each robot. These are known as wireless mesh networks (WMNs). However existing WMNs have limited capacity to support even small robot teams. There is a need for WMNs where links act like dedicated point-to-point connections such as in wired networks. Addressing this problem requires a fundamentally new approach to WMN construction and this thesis is the first comprehensive study in the multi-robot literature to address these challenges. In this thesis, we propose a new class of communication systems called zero mutual interference (ZMI) networks that are able to emulate the point-to-point properties of a wired network over a WMN implementation. We instantiate the ZMI network using a multi-radio multi-channel architecture that autonomously adapts its topology and channel allocations such that all network edges communicate at the full capacity of the radio hardware. We implement the ZMI network on a 100-radio testbed with up to 20-individual nodes and verify its theoretical properties. Mobile robot experiments also demonstrate these properties are practically achievable. The results are an encouraging indication that the ZMI network approach can facilitate the communication demands of large cooperative robot teams deployed in practical problems such as data pipe-lining, decentralised optimisation, decentralised data fusion and sensor networks.
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Shen, Fangyang Sun Min-Te. "Improving system performance for wireless networks." Auburn, Ala, 2008. http://hdl.handle.net/10415/1544.
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Bystřická, Radka. "Analýza komerčního využití Wireless Mesh Network." Master's thesis, Vysoká škola ekonomická v Praze, 2011. http://www.nusl.cz/ntk/nusl-114159.
Повний текст джерелаАнотація:
There is a constant development and continuous progress in the wireless technology field as it is in the all fields of information and communication technologies. One of the latest trends is the wireless mesh network. This type of network brings new features into the wireless field such as multihop, self-configuration, self-organization and self-healing. This enables the usage of wireless networks in new fields and industries or the upgrade of current implementations to meet new market demands. This thesis summarizes theoretical findings from this field from the users' point of view and functionality dimension. This is followed by a summary of possible applications, available technologies and known standards. The second half of the thesis consists of a requirement analysis of a chosen user group (the Fire Rescue Service of the Czech Republic) focusing on application of wireless mesh network for rescue operations. The analysis also includes test criteria and principles for test procedures for this application.
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Scheidemantel, Austin, Ibrahim Alnasser, Benjamin Carpenter, Paul Frost, Shivhan Nettles, and Chelsie Morales. "Situational Wireless Awareness Network." International Foundation for Telemetering, 2010. http://hdl.handle.net/10150/604295.
Повний текст джерелаАнотація:
ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, CaliforniaThe purpose of this paper is to explain the process to implementing a wireless sensor network in order to improve situational awareness in a dense urban environment. Utilizing a system of wireless nodes with Global Positioning System (GPS) and heart rate sensors, a system was created that was able to give both position and general health conditions. By linking the nodes in a mesh network line of sight barriers were overcome to allow for operation even in an environment full of obstruction.
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Matos, Ricardo Jorge Magalhães de. "Context-based wireless mesh networks." Doctoral thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/12450.
Повний текст джерелаАнотація:
Doutoramento em Engenharia ElectrotécnicaIn the modern society, new devices, applications and technologies, with sophisticated capabilities, are converging in the same network infrastructure. Users are also increasingly demanding in personal preferences and expectations, desiring Internet connectivity anytime and everywhere. These aspects have triggered many research efforts, since the current Internet is reaching a breaking point trying to provide enough flexibility for users and profits for operators, while dealing with the complex requirements raised by the recent evolution. Fully aligned with the future Internet research, many solutions have been proposed to enhance the current Internet-based architectures and protocols, in order to become context-aware, that is, to be dynamically adapted to the change of the information characterizing any network entity. In this sense, the presented Thesis proposes a new architecture that allows to create several networks with different characteristics according to their context, on the top of a single Wireless Mesh Network (WMN), which infrastructure and protocols are very flexible and self-adaptable. More specifically, this Thesis models the context of users, which can span from their security, cost and mobility preferences, devices’ capabilities or services’ quality requirements, in order to turn a WMN into a set of logical networks. Each logical network is configured to meet a set of user context needs (for instance, support of high mobility and low security). To implement this user-centric architecture, this Thesis uses the network virtualization, which has often been advocated as a mean to deploy independent network architectures and services towards the future Internet, while allowing a dynamic resource management. This way, network virtualization can allow a flexible and programmable configuration of a WMN, in order to be shared by multiple logical networks (or virtual networks - VNs). Moreover, the high level of isolation introduced by network virtualization can be used to differentiate the protocols and mechanisms of each context-aware VN. This architecture raises several challenges to control and manage the VNs on-demand, in response to user and WMN dynamics. In this context, we target the mechanisms to: (i) discover and select the VN to assign to an user; (ii) create, adapt and remove the VN topologies and routes. We also explore how the rate of variation of the user context requirements can be considered to improve the performance and reduce the complexity of the VN control and management. Finally, due to the scalability limitations of centralized control solutions, we propose a mechanism to distribute the control functionalities along the architectural entities, which can cooperate to control and manage the VNs in a distributed way.
Na sociedade actual, novos dispositivos, aplicações e tecnologias, com capacidades sofisticadas, estão a convergir na mesma infra-estrutura de rede. Os utilizadores são também cada vez mais exigentes nas suas preferências e expectativas pessoais, desejando conetividade `a Internet em qualquer hora e lugar. Estes aspectos têm desencadeado muitos esforços de investigação, dado que a Internet atual está a atingir um ponto de rutura ao tentar promover flexibilidade para os utilizadores e lucros para os operadores, enquanto lida com as exigências complexas associadas `a recente evolução. Em sintonia com a linha de investigação para a Internet do futuro, muitas soluções têm sido propostas para melhorar as arquiteturas e protocolos da Internet atual, de forma a torná-los sensíveis ao contexto, isto é, adaptá-los dinamicamente `a alteração da informação que caracteriza qualquer entidade de rede. Neste sentido, a presente Tese propõe uma nova arquitetura que permite criar várias redes com diferentes características de acordo com o contexto das mesmas, sobre uma única rede em malha sem fios (WMN), cuja infra-estructura e protocolos são muito flexíveis e auto-adaptáveis. Mais especificamente, esta Tese modela o contexto dos utilizadores, que pode abranger as suas preferências de segurança, custo e mobilidade, capacidades dos seus dispositivos ou requisitos de qualidade dos seus serviços, de forma a transformar uma WMN num conjunto de redes lógicas. Cada rede lógica ´e configurada para satisfazer um conjunto de necessidades de contexto do utilizador (como exemplo, suporte de mobilidade elevada e de baixa seguran¸ca). Para implementar esta arquitetura centrada no utilizador, esta Tese utiliza a virtualização de redes, que tem muitas vezes sido defendida como um meio para implementar arquiteturas e serviços de rede de uma forma independente, enquanto permite uma gestão dinâmica dos recursos. Desta forma, a virtualização de redes pode permitir uma configuração flexível e programável de uma WMN, a fim de ser partilhada por várias redes lógicas (ou redes virtuais - VNs). Além disso, o grau de isolamento introduzido pela virtualização de redes pode ser utilizado para diferenciar os protocolos e mecanismos de cada VN baseada em contexto. Esta arquitetura levanta vários desafios para controlar e gerir as VNs em tempo real, e em resposta `a dinâmica dos utilizadores e da WMN. Neste contexto, abordamos os mecanismos para: (i) descobrir e selecionar a VN a atribuir a um utilizador; (ii) criar, adaptar e remover as topologias e rotas das VNs. Também exploramos a possibilidade de considerar a taxa de variação dos requisitos de contexto dos utilizadores de forma a melhorar o desempenho e reduzir a complexidade do controlo e gestão das VNs. Finalmente, devido ´as limitações de escalabilidade das soluções de controlo centralizadas, propomos um mecanismo para distribuir as funcionalidades de controlo ao longo das entidades da arquitectura, que podem cooperar para controlar e gerir as VNs de uma forma distribuída.
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Herms, André. "Dienstgüte in Wireless Mesh Networks." Göttingen Sierke, 2009. http://d-nb.info/997632143/04.
Повний текст джерела
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PEPPAS, NIKOLAOS. "A HYBRID ROUTING PROTOCOL FOR COMMUNICATIONS AMONG NODES WITHHIGH RELATIVE SPEED IN WIRELESS MESH NETWORKS." Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2345.
Повний текст джерелаАнотація:
Wireless mesh networks (WMN) is a new promising wireless technology which uses already available hardware and software components. This thesis proposes a routing algorithm for military applications. More specifically, a specialized scenario consisting of a network of flying Unmanned Aerial Vehicles (UAVs) executing reconnaissance missions is investigated. The proposed routing algorithm is hybrid in nature and uses both reactive and proactive routing characteristics to transmit information. Through simulations run on a specially built stand alone simulator, based on Java, packet overhead, delivery ratio and latency metrics were monitored with respect to varying number of nodes, node density and mobility. The results showed that the high overhead leads to high delivery ratio while latency tends to increase as the network grows larger. All the metrics revealed sensitivity in high mobility conditions.M.S.Cp.E.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Computer Engineering MSCpE
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Li, Yinan. "Integrated Mobility and Service Management for Network Cost Minimization in Wireless Mesh Networks." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/27622.
Повний текст джерелаАнотація:
In this dissertation research, we design and analyze integrated mobility and service manage-
ment for network cost minimization in Wireless Mesh Networks (WMNs). We first investigate the
problem of mobility management in WMNs for which we propose two efficient per-user mobility
management schemes based on pointer forwarding, and then a third one that integrates routing-
based location update and pointer forwarding for further performance improvement.
We further study integrated mobility and service management for which we propose protocols
that support efficient mobile data access services with cache consistency management, and mobile
multicast services. We also investigate reliable and secure integrated mobility and service man-
agement in WMNs, and apply the idea to the design of a protocol for secure and reliable mobile
multicast. The most salient feature of our protocols is that they are optimal on a per-user basis
(or on a per-group basis for mobile multicast), that is, the overall network communication cost
incurred is minimized for each individual user (or group). Per-user based optimization is critical
because mobile users normally have vastly different mobility and service characteristics. Thus, the
overall cost saving due to per-user based optimization is cumulatively significant with an increasing
mobile user population.
To evaluate the performance of our proposed protocols, we develop mathematical models and
computational procedures used to compute the network communication cost incurred and build
simulation systems for validating the results obtained from analytical modeling. We identify optimal
design settings under which the network cost is minimized for our mobility and service management
protocols in WMNs. Intensive comparative performance studies are carried out to compare our
protocols with existing work in the literature. The results show that our protocols significantly
outperform existing protocols under identical environmental and operational settings.
We extend the design notion of integrated mobility and service management for cost minimiza-
tion to MANETs and propose a scalable dual-region mobility management scheme for location-
based routing. The basic design concept is to use local regions to complement home regions and
have mobile nodes in the home region of a mobile node serve as location servers for that node. We
develop a mathematical model to derive the optimal home region size and local region size under
which overall network cost incurred is minimized. Through a comparative performance study, we
show that dual-region mobility management outperforms existing mobility management schemes
based on static home regions.Ph. D.
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Meeran, Mohammad Tariq. "An analysis of voice over Internet Protocol in wireless mesh networks." Thesis, University of the Western Cape, 2012. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8735_1370594169.
Повний текст джерелаАнотація:
This thesis presents an analysis of the impact of node mobility on the quality of service for voice over Internet Protocol in wireless mesh networks. Voice traffic was simulated on such a mesh
network to analyze the following performance metrics: delay, jitter, packet loss and throughput. Wireless mesh networks present interesting characteristics such as multi-hop routing, node mobility, and variable coverage that can impact on quality of service. A reasonable deployment scenario for a small organizational network, for either urban or rural deployment, is considered with three wireless mesh network scenarios, each with 26 mesh nodes. In the first scenario, all mesh nodes are stationary. In the second scenario, 10 nodes are mobile and 16 nodes are stationary.
Finally, in the third scenario, all mesh nodes are mobile. The mesh nodes are simulated to move at a walking speed of 1.3m per second. The results show that node mobility can increase packet
loss, delay, and jitter. However, the results also show that wireless mesh networks can provide acceptable quality of service, providing that there is little or no background traffic generated by other
applications. In particular, the results demonstrate that jitter across all scenarios remains within humanacceptable tolerances. It is therefore recommended that voice over Internet Protocol implementations on wireless mesh networks with background traffic be supported by quality of service standards
otherwise they can lead to service delivery failures. On the other hand, voice-only
esh networks, even with mobile nodes, offer an attractive alternative voice over Internet Protocol platform.
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Kongara, Harish Agrawal Prathima. "Performance optimization of wireless mesh networks." Auburn, Ala, 2009. http://hdl.handle.net/10415/1620.
Повний текст джерела
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Chitedze, Zimani. "Mobility management for Wi-Fi infrastructure and mesh networks." University of the Western Cape, 2012. http://hdl.handle.net/11394/2960.
Повний текст джерелаАнотація:
Magister Scientiae - MScThis thesis shows that mobility management protocols for infrastructure Internet may be used in a wireless mesh network environment. In this research Mobile IPv6 and Fast Handover for Hierarchical Mobile IPv6 are successfully implemented in a wireless mesh network environment. Two experiments were carried out: vertical and horizontal handover simulations. Vertical handover simulation involved a heterogeneous wireless environment comprising both wireless local area and wireless mesh networks. An OPNET Mobile IPv6 model was used to simulate the vertical handover experiment. Horizontal handover simulation involved Mobile IPv6 and Fast Handover for Hierarchical Mobile IPv6 applied in ns2 wireless mesh network. The vertical handover results show that MIPv6 is able to manage vertical handover between wireless local area and wireless mesh network. The horizontal handover results illustrate that in mesh networks, Fast Handover for Hierarchical Mobile IPv6's performance is superior to Mobile IPv6. Fast Handover for Hierarchical Mobile IPv6 generates more throughput and less delay than Mobile IPv6. Furthermore, Fast Handover for Hierarchical Mobile IPv6 drops less data packets than Mobile IPv6. The simulations indicate that even though there are multi-hop communications in wireless mesh networks, the performance of the multi-hop routing may not play a big role in the handover performance. This is so because the mesh routers are mostly static and the multi-hop routes are readily available. Thus, the total handover delay is not affected too much by the WMN hops in the paths for signaling message transmission.
South Africa
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Brolin, Jonas, and Mikael Hedegren. "Packet Aggregation in Linux." Thesis, Karlstad University, Division for Information Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-1726.
Повний текст джерелаАнотація:
Voice over IP (VoIP) traffic in a multi-hop wireless mesh network (WMN) suffers from a large overhead due to mac/IP/UDP/RTP headers and time collisions. A consequence of the large overhead is that only a small number of concurrent VoIP calls can be supported in a WMN[17]. Hop-to-hop packet aggregation can reduce network overhead and increase the capacity. Packet aggregation is a concept which combines several small packets, destined to a common next-hop destination, to one large packet. The goal of this thesis was to implement packet aggregation on a Linux distribution and to increase the number of concurrent VoIP calls. We use as testbed a two-hop WMN with a fixed data rate of 2Mbit/s. Traffic was generated between nodes using MGEN[20] to simulate VoIP behavior. The results from the tests show that the number of supported concurrent flows in the testbed is increased by 135% compared to unaggregated traffic.
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Khaled, Shah Mostafa. "Heuristic algorithms for wireless mesh network planning." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, c2012, 2012. http://hdl.handle.net/10133/3266.
Повний текст джерелаАнотація:
Technologies like IEEE 802.16j wireless mesh networks are drawing increasing attention of
the research community. Mesh networks are economically viable and may extend services
such as Internet to remote locations. This thesis takes interest into a planning problem in
IEEE 802.16j networks, where we need to establish minimum cost relay and base stations to
cover the bandwidth demand of wireless clients. A special feature of this planning problem
is that any node in this network can send data to at most one node towards the next hop,
thus traffic flow is unsplittable from source to destination.
We study different integer programming formulations of the problem. We propose four
types of heuristic algorithms that uses greedy, local search, variable neighborhood search
and Lagrangian relaxation based approaches for the problem. We evaluate the algorithms
on database of network instances of 500-5000 nodes, some of which are randomly generated
network instances, while other network instances are generated over geometric distribution.
Our experiments show that the proposed algorithms produce satisfactory result
compared to benchmarks produced by generalized optimization problem solver software.x, 131 leaves : ill. ; 29 cm
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Darehshoorzadeh, Amir. "Opportunistic routing in wireless mesh networks." Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/83765.
Повний текст джерелаАнотація:
Advances in communication and networking technologies are rapidly making ubiquitous network connectivity a reality. In recent years, Wireless Mesh Networks (WMNs) have already become very popular and been receiving an increasing amount of attention by the research community. Basically, a
WMN consists of simple mesh routers and mesh clients, where mesh routers form the backbone of WMN. Due to the limited transmission range of the radio, many pairs of nodes in WMN may not be able to communicate directly, hence they need other intermediate nodes to forward packets for
them. Routing in such networks is an important issue and it poses great challenges.
Opportunistic Routing (OR) has been investigated in recent years as a way to increase the performance of WMNs by exploiting its broadcast nature. In OR, in contrast to traditional routing, instead of pre-selecting a single specic node to be the next-hop as a forwarder for a packet, an
ordered set of nodes (referred to as candidates) is selected as the potential next-hop forwarders. Thus, the source can use multiple potential paths to deliver the packets to the destination. More specically, when the current node transmits a packet, all the candidates that successfully receive it will
coordinate with each other to determine which one will actually forward it, while the others will simply discard the packet. This dissertation studies the properties, performance, maximum gain, candidate selection algorithms and multicast delivery issues about Opportunistic Routing in WMNs.
Firstly, we focus on the performance analysis of OR by proposing a Discrete Time Markov Chain (DTMC). This model can be used to evaluate OR in terms of expected number of transmissions from the source to the destination.
Secondly, we apply our Markov model to compare relevant candidate selection algorithms that have been proposed in the literature. They range from non-optimum, but simple, to optimum, but with a high computational cost.
Thirdly, the set of candidates which a node uses and priority order of them have a signicant impact on the performance of OR. Therefore, using a good metric and algorithm to select and order the candidates are key factors in designing an OR protocol. As the next contribution we propose a new metric that measures the expected distance progress of sending a packet using a set of candidates. Based on this metric we propose a candidate selection algorithm which its performance is very close to the optimum algorithm although our algorithm runs much faster.
Fourthly, we have investigated the maximum gain that can be obtained using OR. We have obtained some equations that yield the distances of the candidates in OR such that the per transmission progress towards the destination is maximized. Based on these equations we have proposed a
novel candidate selection algorithm. Our new algorithm only needs the geographical location of nodes. The performance of our proposal is very close to the optimum candidate selection algorithm although our algorithm runs much faster.
Finally, using OR to support multicast is an other issue that we have investigated in this thesis. We do so by proposing a new multicast protocol which uses OR. Unlike traditional multicast protocols, there is no designated next-hop forwarder for each destination in our protocol, thus the delivery ratio is maximized by taking advantage of spatial diversity.
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Jun, Jangeun. "Capacity Estimation of Wireless Mesh Networks." NCSU, 2002. http://www.lib.ncsu.edu/theses/available/etd-11062002-163505/.
Повний текст джерелаАнотація:
The goal of this research is to estimate the capacity of wireless mesh networks (WMNs). WMNs have unique topology and traffic patterns when compared to conventional wireless Internet access networks. In WMNs, user nodes act as a host and a router simultaneously and form a meshed topology. Traffic is forwarded towards a gateway connected to the Internet by cooperating user nodes in a multihop fashion. Since the considered WMNs use IEEE 802.11 for medium access control and physical layer implementation, theoretical maximum throughput and fairness issues in IEEE 802.11 networks are investigated as a preliminary framework for the capacity estimation of WMN. Due to a centralized traffic pattern and meshed topology, forwarded traffic becomes heavier as it gets closer to the gateway. The characteristics of the traffic behavior in WMNs are thoroughly examined and an analytical solution for capacity estimation is presented. The analytical solution is derived for various topologies and validated using simulations.
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Shah, Kartik Beard Cory. "Throughput enhancement using wireless mesh networks." Diss., UMK access, 2008.
Знайти повний текст джерелаАнотація:
Thesis (M.S.)--School Computing and Engineering. University of Missouri--Kansas City, 2008."A thesis in electrical engineering." Typescript. Advisor: Cory C. Beard. Vita. Title from "catalog record" of the print edition Description based on contents viewed Sept. 12, 2008. Includes bibliographical references (leaf 42). Online version of the print edition.
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Subramanian, Jayashree Ph D. Massachusetts Institute of Technology. "Efficient flooding for wireless mesh networks." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/71490.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 113-116).
Flooding in wireless mesh networks involves distributing some data from one node to rest of the nodes in the network. This dissertation proposes UFlood, a flooding protocol for wireless mesh networks that targets large file transfers, such as software updates, where achieving high throughput (minimizing the time to complete the flood to all nodes) and low airtime (lower the time each node spends in transmitting packets, and thus lower the impact on other wireless traffic) are both important. The central challenge in good flooding performance is the choice of senders for each transmission opportunity. At each time during a flood, some parts of the network will have received more data than others. The set of best sending nodes lies along the boundaries between these regions, and evolves with time in ways that are difficult to predict. UFlood's key new idea is a distributed heuristic to dynamically choose the senders likely to lead to all nodes receiving the flooded data in the least time. The mechanism takes into account which data nearby receivers already have as well as inter-node channel quality. The mechanism includes a novel bit-rate selection algorithm that trades off the speed of high bit-rates against the larger number of nodes likely to receive low bit-rates. Unusually, UFlood uses both random network coding to increase the usefulness of each transmission and detailed feedback about what data each receiver already has; the feedback is critical in deciding which node's coded transmission will have the most benefit to receivers. The required feedback is potentially voluminous, but UFlood includes novel techniques to reduce its cost. The dissertation concludes that careful choice of senders allows UFlood to achieve 150% higher throughput than MORE, a known high-throughput flooding protocol, using 65% less time transmitting. UFlood uses 54% lower airtime than MNP, an existing flooding protocol to minimize airtime, and achieves 300% higher throughput.
by Jayashree Subramanian.
Ph.D.
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Batbayar, Khulan. "Connectivity sharing for wireless mesh networks." Doctoral thesis, Universitat Politècnica de Catalunya, 2022. http://hdl.handle.net/10803/673612.
Повний текст джерелаАнотація:
Internet access is still unavailable to one-third of the world population due to the lack of infrastructure, high cost, and the digital divide. Many access-limited communities opt for shared Internet access where they build common network infrastructures to mitigate the cost. Internet connectivity in such infrastructures is typically provided by several limited, sometimes non-dedicated, gateways. Client nodes, i.e., the end-user hosts, use one gateway and switch to another when the first fails. In this scheme, the gateway configuration is done manually on the end-user side. This form of Internet connectivity is widespread and has the advantage that no central control is required, but it is also unreliable and inefficient due to several factors, such as unbalanced traffic load across the gateways. There is no doubt that the network would benefit from a gateway selection mechanism that can provide good connectivity to the client node as well as balanced load distribution and a dynamic adaptation to the current network state. However, providing such a dynamic gateway selection is complicated: since the perceived performance of the gateways changes frequently and might depend on the location of the client node in the network, and optimal selection would require the continuous monitoring of the gateway performance by the client node. The cost of such network-wide performance monitoring is high in large-scale networks and can outweigh the benefits of the dynamic gateway selection.
The thesis's goal is to design a low-cost, distributed mechanism that provides an efficient and dynamic gateway selection while considering the overall balanced gateway selection distribution. To this end, we have split the problem of gateway selection into different sub-problems.
First, we focus on reducing the cost of gateway performance monitoring. We propose an approach to reduce the number of monitoring requests generated by each node and analyze its effect on the gateway selection. Then, we present a collaborative monitoring method that allows neighbor nodes to share the load of the gateway monitoring. We show that every node can carry out the necessary tasks: performance monitoring, collaboration with its neighbors, and fault tolerance measures, with little computation and communication overhead.
Second, to improve the gateway selection, we focus on making a selection decision that fulfills the individual performance requirements of the client nodes as well as global load balancing requirements. The solutions developed by us for the different sub-problems are embedded into a general and extensible, layered framework for gateway selection that we have called the Sense-Share-Select framework.
Experimental validation and comparison with existing methods show that our framework provides accurate collaborative performance monitoring, improves the QoE for the nodes, and distributes the client nodes over the gateways in a balanced manner. The simplicity and flexibility of the framework make it adaptable to other network domains such as IoT networks and other scenarios where resource monitoring and load balancing are required.El acceso a Internet aún no está disponible para un tercio de la población mundial debido a la falta de infraestructuras, el alto costo y la brecha digital. Muchas comunidades con acceso limitado optan por el acceso compartido a Internet donde construyen infraestructuras de red comunitaria para mitigar el costo. La conectividad a Internet en dichas infraestructuras suele estar a cargo de varias puerta de enlaces limitadas en recursos, y a veces no dedicadas. Los nodos de cliente, es decir, los hosts de usuario final, utilizan una puerta de enlace y cambian a otra cuando falla la primera. En este esquema, la configuración de la puerta de enlace se realiza manualmente en el lado del usuario final. Esta forma de conectividad a Internet está muy extendida y tiene la ventaja de que no se requiere un control central, pero tampoco es confiable y eficiente debido a varios factores, como una carga desequilibrada de tráfico a través de las puertas de enlace. No hay duda de que la red se beneficiaría de un mecanismo de selección de pasarela que pueda proporcionar una buena conectividad al nodo cliente, así como una distribución equilibrada de la carga y una adaptación dinámica al estado actual de la red. Sin embargo, proporcionar una selección de puerta de enlace tan dinámica es complicado: dado que el rendimiento percibido de las puertas de enlace cambia con frecuencia y podría depender de la ubicación del nodo cliente en la red, y la selección óptima requeriría la supervisión continua del rendimiento de la puerta de enlace por parte del nodo cliente. El costo de dicha supervisión del rendimiento en toda la red es muy alto en redes de gran escala y puede superar los beneficios de la selección de puerta de enlace dinámica. El objetivo de la tesis es diseñar un mecanismo distribuido de bajo costo que proporcione una selección de puerta de enlace dinámica y eficiente al tiempo que considera la distribución general de selección de puerta de enlace equilibrada. Con este fin, hemos dividido el problema de la selección de la puerta de enlace en diferentes subproblemas. Primero, nos enfocamos en reducir el coste del monitoreo del rendimiento de la puerta de enlace. Proponemos un enfoque para reducir la cantidad de solicitudes de monitoreo generadas por cada nodo y analizar su efecto en la selección de la puerta de enlace. Luego, presentamos un método de monitoreo colaborativo que permite a los nodos vecinos compartir la carga del monitoreo de la puerta de enlace. Demostramos que cada nodo puede realizar las tareas necesarias: monitoreo del rendimiento, colaboración con sus vecinos y medidas de tolerancia a fallas, con poca sobrecarga de cómputo y comunicación. En segundo lugar, para mejorar la selección de la puerta de enlace, nos centramos en tomar una decisión de selección que cumpla con los requisitos de rendimiento individuales de los nodos del cliente, así como con los requisitos de equilibrio de carga global. Las soluciones desarrolladas por nosotros para los diferentes subproblemas están integradas en un marco general y extensible en capas para la selección de puertas de enlace que hemos llamado el marco Sense-Share-Select. La validación experimental y la comparación con los métodos existentes muestran que nuestro marco proporciona un monitoreo de rendimiento colaborativo preciso, mejora la QoE para los nodos y distribuye los nodos del cliente a través de las puertas de enlace de manera equilibrada. La simplicidad y flexibilidad del marco lo hacen adaptable a otros dominios de red, como las redes de IoT y otros escenarios donde se requiere monitoreo de recursos y equilibrio de carga.
Doctorat Erasmus Mundus en computació distribuïda
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Lim, Christopher. "Optimizing access radio in multi-radio mesh network /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CSED%202009%20LIM.
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Lee, Myounghwan. "Quality of service with DiffServ architecture in hybrid mesh/relay networks." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34694.
Повний текст джерелаАнотація:
The objective of this research is to develop an optimized quality of service (QoS) assurance algorithm with the differentiated services (DiffServ) architecture, and a differentiated polling algorithm with efficient bandwidth allocation for QoS assurance in the hybrid multi-hop mesh/relay networks. These wide area networks (WANs), which will employ a connection-based MAC protocol, along with QoS-enabled wireless local area networks (WLANs) that use a contention-based MAC protocol, need to provide an end-to-end QoS guarantee for data communications, particularly QoS-sensitive multimedia communications.
Due to the high cost of construction and maintenance of infrastructure in wireless networks, engineers and researchers have focused their investigations on wireless mesh/relay networks with lower cost and high scalability. For current wireless multi-hop networks, an end-to-end QoS guarantee is an important functionality to add, because the demand for real-time multimedia communications has recently been increasing. For real-time multimedia communication in heterogeneous networks, hybrid multi-hop mesh/relay networks using a connection-based MAC protocol, along with QoS-enabled WLANs that use a contention-based MAC protocol can be an effective multi-hop network model , as opposed to multi-hop networks with a contention-based MAC protocol without a QoS mechanism. To provide integrated QoS support for different QoS mechanisms, the design of the cross-layer DiffServ architecture that can be applied in wireless multi-hop mesh/relay networks with WLANs is desirable.
For parameterized QoS that requires a specific set of QoS parameters in hybrid multi-hop networks, an optimized QoS assurance algorithm with the DiffServ architecture is proposed here that supports end-to-end QoS through a QoS enhanced WAN for multimedia communications.
For a QoS assurance algorithm that requires a minimum per-hop delay, the proper bandwidth to allow the per-hop delay constraint needs to be allocated. Therefore, a polling algorithm with a differentiated strategy at multi-hop routers is proposed here. The proposed polling algorithm at a router differentially computes and distributes the polling rates for routers according to the ratio of multimedia traffic to overall traffic, the number of traffic connections, and the type of polling service.
By simulating the architecture and the algorithms proposed in this thesis and by analyzing traffic with the differentiated QoS requirement, it is shown here that the architecture and the algorithms produce an excellent end-to-end QoS guarantee.
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SANTHANAM, LAKSHMI. "Integrated Security Architecture for Wireless Mesh Networks." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1202846575.
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Grobler, Magdalena Johanna. "Using topological information in opportunistic network coding / by Magdalena Johanna (Leenta) Grobler." Thesis, North-West University, 2008. http://hdl.handle.net/10394/2639.
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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.
Повний текст джерелаАнотація:
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
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Rahat, Alma As-Aad Mohammad. "Hybrid evolutionary routing optimisation for wireless sensor mesh networks." Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/21330.
Повний текст джерелаАнотація:
Battery powered wireless sensors are widely used in industrial and regulatory monitoring applications. This is primarily due to the ease of installation and the ability to monitor areas that are difficult to access. Additionally, they can be left unattended for long periods of time. However, there are many challenges to successful deployments of wireless sensor networks (WSNs). In this thesis we draw attention to two major challenges. Firstly, with a view to extending network range, modern WSNs use mesh network topologies, where data is sent either directly or by relaying data from node-to-node en route to the central base station. The additional load of relaying other nodes’ data is expensive in terms of energy consumption, and depending on the routes taken some nodes may be heavily loaded. Hence, it is crucial to locate routes that achieve energy efficiency in the network and extend the time before the first node exhausts its battery, thus improving the network lifetime. Secondly, WSNs operate in a dynamic radio environment. With changing conditions, such as modified buildings or the passage of people, links may fail and data will be lost as a consequence. Therefore in addition to finding energy efficient routes, it is important to locate combinations of routes that are robust to the failure of radio links. Dealing with these challenges presents a routing optimisation problem with multiple objectives: find good routes to ensure energy efficiency, extend network lifetime and improve robustness. This is however an NP-hard problem, and thus polynomial time algorithms to solve this problem are unavailable. Therefore we propose hybrid evolutionary approaches to approximate the optimal trade-offs between these objectives. In our approach, we use novel search space pruning methods for network graphs, based on k-shortest paths, partially and edge disjoint paths, and graph reduction to combat the combinatorial explosion in search space size and consequently conduct rapid optimisation. The proposed methods can successfully approximate optimal Pareto fronts. The estimated fronts contain a wide range of robust and energy efficient routes. The fronts typically also include solutions with a network lifetime close to the optimal lifetime if the number of routes per nodes were unconstrained. These methods are demonstrated in a real network deployed at the Victoria & Albert Museum, London, UK.
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Pieskä, Marcus. "Emulating Software-Defined Small-Cell Wireless Mesh Networks Using ns-3 and Mininet." Thesis, Karlstads universitet, Institutionen för matematik och datavetenskap (from 2013), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-68795.
Повний текст джерелаАнотація:
The objective of this thesis was to create a network emulator, suitable for evaluatingsolutions in a small-cell wireless mesh SDN backhaul network environment, by integratingexisting software. The most important efforts in this process have been a transparentintegration of Mininet and ns-3 at both the data and the control plane, with ns-3 servingas the front-end. The goal has been to design the system such that solutions revolvingaround fast failover, resilient routing, and energy efficient small cell management may beevaluated. The constituent components include an augmented ns-3 WiFi module withmillimeter wave communication capabilities; a socket API suitable for remote-controllermanagement, as well as the network emulator Mininet. Mininet in turn integrates OpenvSwitch, virtual hosts in the form of Linux network namespaces, and OpenFlow controllers.The work has also included a brief evaluation of the system, which revealed that the designhas a fundamental flaw.SOCRA
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Kripakaran, Ramakrishnan. "Effective Strategies for Mesh Router Selection in Wireless Mesh Networks." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1267460860.
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Al-Saadi, Ahmed. "Cognitive network framework for heterogeneous wireless mesh systems." Thesis, Cardiff University, 2016. http://orca.cf.ac.uk/96622/.
Повний текст джерелаАнотація:
Heterogeneous wireless mesh networks (WMN) provide an opportunity to secure higher network capacity, wider coverage and higher quality of service (QoS). However, heterogeneous systems are complex to configure because of the high diversity of associated devices and resources. This thesis introduces a novel cognitive network framework that allows the integration of WMNs with long-term evolution (LTE) networks so that none of the overlapped frequency bands are used. The framework consists of three novel systems: the QoS metrics management system, the heterogeneous network management system and the routing decision-making system. The novelty of the QoS metrics management system is that it introduces a new routing metric for multi-hop wireless networks by developing a new rate adaptation algorithm. This system directly addresses the interference between neighbouring nodes, which has not been addressed in previous research on rate adaptation for WMN. The results indicated that there was a significant improvement in the system throughput by as much as to 90%. The routing decision-making system introduces two novel methods to select the transmission technology in heterogeneous nodes: the cognitive heterogeneous routing (CHR) system and the semantic reasoning system. The CHR method is used to develop a novel reinforcement learning algorithm to optimise the selection of transmission technology on wireless heterogeneous nodes by learning from previous actions. The semantic reasoning method uses ontologies and fuzzy-based semantic reasoning to facilitate the dynamic addition of new network types to the heterogeneous network. The simulation results showed that the heterogeneous network outperformed the benchmark networks by up to 200% of the network throughput.
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Zulu, Docas Dudu. "Packet aggregation for voice over internet protocol on wireless mesh networks." Thesis, University of the Western Cape, 2012. http://hdl.handle.net/11394/4403.
Повний текст джерелаАнотація:
>Magister Scientiae - MScThis thesis validates that packet aggregation is a viable technique to increase call capacity for Voice over Internet Protocol over wireless mesh networks. Wireless mesh networks are attractive ways to provide voice services to rural communities. Due to the ad-hoc routing nature of mesh networks, packet loss and delay can reduce voice quality. Even on non-mesh networks, voice quality is reduced by high overhead, associated with the transmission of multiple small packets. Packet aggregation techniques are proven to increase VoIP performance and thus can be deployed in wireless mesh networks. Kernel level packet aggregation was initially implemented and tested on a small mesh network of PCs running Linux, and standard baseline vs. aggregation tests were conducted with a realistic voice traffic profile in hop-to-hop mode. Modifications of the kernel were then transferred to either end of a nine node 'mesh potato' network and those tests were conducted with only the end nodes modified to perform aggregation duties. Packet aggregation increased call capacity expectedly, while quality of service was maintained in both instances, and hop-to-hop aggregation outperformed the end-to-end configuration 4:1. However, implementing hop-to-hop in a scalable fashion is prohibitive, due to the extensive kernel level debugging that must be done to achieve the call capacity increase. Therefore, end-to-end call capacity increase is an acceptable compromise for eventual scalable deployment of voice over wireless mesh networks.
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Damle, Ameya. "Hybrid routing with periodic mesh updates in wireless mesh networks." Ann Arbor, Mich. : ProQuest, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1432319.
Повний текст джерелаАнотація:
Thesis (M.S. in Electrical Engineering)--S.M.U.Title from PDF title page (viewed May 23, 2007). Source: Masters Abstracts International, Volume: 44-04, page: 1923. Adviser: Dinesh Rajan. Includes bibliographical references.
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Cavalcanti, de Castro Marcel. "Enhancing P2P Systems over Wireless Mesh Networks." Doctoral thesis, Karlstads universitet, Avdelningen för datavetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-8691.
Повний текст джерелаАнотація:
Due to its ability to deliver scalable and fault-tolerant solutions, applications based on the peer-to-peer (P2P) paradigm are used by millions of users on the internet. Recently, wireless mesh networks (WMNs) have attracted a lot of interest from both academia and industry, because of their potential to provide flexible and alternative broadband wireless internet connectivity. However, due to various reasons such as unstable wireless link characteristics and multi-hop forwarding operation, the performance of current P2P systems is rather low in WMNs. This dissertation studies the technological challenges involved while deploying P2P systems over WMNs. We study the benefits of location-awareness and resource replication to the P2P overlay while targeting efficient resource lookup in WMNs. We further propose a cross-layer information exchange between the P2P overlay and the WMN in order to reduce resource lookup delay by augmenting the overlay routing table with physical neighborhood and resource lookup history information. Aiming to achieve throughput maximization and fairness in P2P systems, we model the peer selection problem as a mathematical optimization problem by using a set of mixed integer linear equations. A study of the model reveals the relationship between peer selection, resource replication and channel assignment on the performance of P2P systems over WMNs. We extend the model by formulating the P2P download problem as chunk scheduling problem. As a novelty, we introduce constraints to model the capacity limitations of the network due to the given routing and channel assignment strategy. Based on the analysis of the model, we propose a new peer selection algorithm which incorporates network load information and multi-path routing capability. By conducting testbed experiments, we evaluate the achievable throughput in multi-channel multi-radio WMNs. We show that the adjacent channel interference (ACI) problem in multi-radio systems can be mitigated, making better use of the available spectrum. Important lessons learned are also outlined in order to design practical channel and channel bandwidth assignment algorithms in multi-channel multi-radio WMNs.
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Munawar, Mohammad Ahmad. "Multi-interface Multi-channel wireless mesh networks." Thesis, University of Waterloo, 2004. http://hdl.handle.net/10012/875.
Повний текст джерелаАнотація:
In this thesis we propose a multi-channel wireless network based on nodes that use multiple 802. 11 radio interfaces. The proposed system is singular, as it does not require new hardware or a new MAC, but instead leverages commodity 802. 11-based products. With this system, we target scenarios where the nodes are stationary and where their location can often be controlled. We evaluate the performance in this setup using an ad-hoc network approach whereby nodes generate as well as forward data. We also present and appraise a purely-wireless multi-channel infrastructure, which operates like the WLAN infrastructure-based networks in existence today, but without any fixed-line support. In such an infrastructure nodes dedicated for routing purposes provide wireless connectivity to users. We show that a multi-interface system provide significantly higher capacity in many scenarios. Our work puts forward various challenges, points to various anomalies in the operation of the 802. 11 MAC protocol, and shows the need to tackle unfairness issues. Our experiments demonstrate that the mere use of more dual-interface nodes does not necessarily create higher capacity. We also show that traffic differentiation significantly increases aggregate throughput in realistic scenarios. Finally, we provide an example of how simple channel-allocation algorithms in controlled random topologies can allow us to take advantage of a multi-interface system.
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Mynampati, Vittal Reddy, Dilip Kandula, Raghuram Garimilla, and Kalyan Srinivas. "Performance and Security of Wireless Mesh Networks." Thesis, Blekinge Tekniska Högskola, Avdelningen för telekommunikationssystem, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2901.
Повний текст джерелаАнотація:
The thesis aims to find issues that may affect the performance of meshed wireless networks. There is no denying the fact that out of the wireless technologies being used in today’s environment, the wireless meshed technology is one of the most advanced and can be viewed as the technology of the future. This thesis deals closely with aspects like throughput, security and performance as these metrics have a direct influence on the performance of the wireless mesh.The thesis is subdivided into various categories explaining the primary structure of wireless mesh networks. Performance of the network has always been a key issue and reliability is the core metric of evaluating the quality of a network. Routing protocols for these networks and which help in improving the performance are examined and the best routing protocol is suggested. This helps to improve the throughput which is the main aspect for maintaining a good performance. The main problem with wireless networks is making them security. This area is also considered as it improves the performance of the whole network. Also the network should be scalable to properly utilize the frequency and get optimal performance. This is required for the successful delivery of data packets. Thus, this area is also investigated together with some other factors that influence the behaviour of these networks. Last, but not least, we provide a discussion about possible future work as well as specifying a system that will help to increase the performance.
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Baumann, Rainer. "Building scalable and robust wireless mesh networks." Aachen Shaker, 2007. http://e-collection.ethbib.ethz.ch/view/eth:29857?q=Baumann%20mesh.
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Zhang, Zhenxia. "Handoff Management Schemes in Wireless Mesh Networks." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23073.
Повний текст джерелаАнотація:
Recent advances in Wireless Mesh Networks (WMNs) have overcome the drawbacks of traditional wired networks and wireless ad hoc networks. WMNs will play a leading role in the next generation of networks, and the question of how to provide smooth mobility for WMNs is the driving force behind the research. The inherent characteristics of WMNs, such as relatively static backbones and highly mobile clients, require new handoff management solutions to be designed and implemented.
This thesis first presents our research work on handoff management schemes in traditional WMNs. In general, a handoff process includes two parts, the MAC layer handoff and the network layer handoff. For the MAC layer handoff, a self-configured handoff scheme with dynamic adaptation is presented. Before the mobile node starts the probe process, it configures parameters for each channel to optimize the scan process. Moreover, a fast authentication scheme to reduce authentication latency for WiFi-based mesh networks is introduced. A tunnel is introduced to forward data packets between the new access router and the original reliable access router to recover data communication before the complete authentication process is finished. To minimize the network layer handoff latency, a hybrid routing protocol for forwarding packets is proposed: this involves both the link layer routing and the network layer routing. Based on the hybrid routing protocol, both intra-domain and inter-domain handoff management have been designed to support smooth roaming in WMNs. In addition, we extend our work to Vehicular Mesh Networks (VMNs). Considering the characteristics of VMNs, a fast handoff scheme is introduced to reduce handoff latency by using a multi-hop clustering algorithm. Using this scheme, vehicle nodes are divided into different multi-hop clusters according to the relative mobility. Some vehicle nodes are selected as assistant nodes; and these assistant nodes will help the cluster head node to determine the next access router for minimizing handoff latency. Extensive simulation results demonstrate that the proposed scheme can reduce handoff latency significantly.
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Yu, Xiaobo. "Distributed resource management for wireless mesh networks." Thesis, University of Surrey, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.551148.
Повний текст джерелаАнотація:
Wireless mesh networking is expected to play an important role in the future Inter- net. It can facilitate network coverage at less expense, making it a fitting candidate for multi-hop communications in distributed wireless environments. However, Wireless Mesh Networks (WMNs) still suffer from many problems such as channel contention, interference low efficiency of bandwidth utilization, etc. Therefore, guaranteeing Quality of Service (QoS) for multimedia applications while ensuring high bandwidth efficiency is a challenging task in WMNs. In this context, this thesis aims at solving these problems from a resource management at Medium Access Control (MAC) layer point of view. The thesis first surveys the existing protocol designs for Resource Reservation (RR) in IEEE 802.11-based wireless networks. It advises the necessity of MAC layer protocol design for guaranteeing the QoS for Real-Time Sessions (RTSNs) while optimizing bandwidth efficiency. Following the outcomes of the investigation, the thesis proposes an analytical framework to evaluate the guaranteed QoS performance of distributed hybrid MAC RR schemes in distributed single-hop wireless networks. After that, the thesis devises a comprehensive hybrid MAC RR scheme that consists of a distributed hybrid MAC scheduling mechanism and a distributed Admission Control (AC) algorithm. The hybrid MAC scheduling mechanism can provide contention-free channel access for RTSNs and reserve dedicated and periodic resources for them to ensure their QoS guaranteeing. In addition, the mechanism can implement concurrent transmission in the Contention-Free Period (CFP) in order to enhance the bandwidth usage for the reserved resources. The distributed Admission Control Algorithm (ACA), on the other harid, can cooperate with the distributed hybrid MAC scheduling mechanism in order to make optimized RR for RTSNs with specific QoS requirements. Furthermore, the proposed distributed ACA can help MAC scheduler to implement resource sharing. It can permit several RTSNs to share an identical Transmission Opportunity (TXOP) in the CFP provided that each of the resource sharer can obtain guaranteed QoS. This can directly improve the efficiency of bandwidth utilization.
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Nawaf, Liqaa. "Optimizing infrastructure placement in Wireless Mesh Networks." Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/100966/.
Повний текст джерелаАнотація:
Wireless Mesh Networks (WMNs) are a promising flexible and low cost technology to efficiently deliver broadband services to communities. In a WMN, a mesh router is deployed at each house, which acts both as a local access point and a relay to other nearby houses. Since mesh routers typically consist of off-the-shelf equipment, the major cost of the network is in the placement and management of Internet Transit Access Points (ITAP) which act as the connection to the internet. In designing a WMN, we therefore aimed to minimize the number of ITAPs required whilst maximizing the traffic that could be served to each house. We investigated heuristic and meta-heuristic approaches with an efficient combination of move operators to solve these placement problems by using single and multi-objective formulations. Many real-world optimisation problems involve dealing with multiple and sometimes conflicting objectives. A multi-objective approach to optimize WMN infrastructure placement design with three conflicting objectives is presented: it aims to minimize the number of ITAPs, maximize the fairness of bandwidth allocation and maximize the coverage to mesh clients. We discuss how such an approach could allow more effective ITAP deployment, enabling a greater number of consumers to obtain internet services. Two approaches are compared during our investigation of multi-objective optimization, namely the weighted sum approach and the use of an evolutionary algorithm. In this thesis we investigate a multi-objective optimization algorithm to solve the WMN infrastructure placement problem. The move operators demonstrate their efficiency when compared to simple Hill Climbing (HC) and Simulated Annealing (SA) for the single objective method.
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Nicholas, Paul J. "Optimal transmitter placement in wireless mesh networks." Thesis, Monterey, Calif. : Naval Postgraduate School, 2009. http://handle.dtic.mil/100.2/ADA501886.
Повний текст джерелаАнотація:
Thesis (M.S. in Operations Research)--Naval Postgraduate School, June 2009.Thesis Advisor(s): Alderson, David. "June 2009." Author(s) subject terms: Wireless Mesh Networks, Humanitarian Assistance, Disaster Relief, Distributed Operations, Enhanced Company Operations, Network Design, Nonlinear Programming, Terrain Integrated Rough Earth Model, TIREM, Hata COST-231, Simultaneous Routing and Resource Allocation, Dividing Rectangles, DIRECT, Access Points, Access Point Placement, C++ Description based on title screen as viewed on July 13, 2009. Includes bibliographical references (p. 119-122). Also available in print.