To see the other types of publications on this topic, follow the link: Wireless mesh networks.
Dissertations / Theses on the topic 'Wireless mesh networks'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Wireless mesh networks.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Abdalla, Taha. "Scalable Wireless Mesh Networks." University of the Western Cape, 2016. http://hdl.handle.net/11394/5868.
Full textAbstract:
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.
2
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.
Full textAbstract:
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.
3
Herms, André. "Dienstgüte in Wireless Mesh Networks." Göttingen Sierke, 2009. http://d-nb.info/997632143/04.
Full text
4
Matos, Ricardo Jorge Magalhães de. "Context-based wireless mesh networks." Doctoral thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/12450.
Full textAbstract:
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.
5
Kongara, Harish Agrawal Prathima. "Performance optimization of wireless mesh networks." Auburn, Ala, 2009. http://hdl.handle.net/10415/1620.
Full text
6
Qi, Bing Biaz Saad. "Routing metrics for multi-hop wireless MESH networks." Auburn, Ala., 2009. http://hdl.handle.net/10415/1705.
Full text
7
Darehshoorzadeh, Amir. "Opportunistic routing in wireless mesh networks." Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/83765.
Full textAbstract:
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.
8
Jun, Jangeun. "Capacity Estimation of Wireless Mesh Networks." NCSU, 2002. http://www.lib.ncsu.edu/theses/available/etd-11062002-163505/.
Full textAbstract:
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.
9
Shah, Kartik Beard Cory. "Throughput enhancement using wireless mesh networks." Diss., UMK access, 2008.
Find full textAbstract:
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.
10
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.
Full textAbstract:
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.
11
Zhang, Xiaowen. "Resource Management and Optimization in Wireless Mesh Networks." FIU Digital Commons, 2009. http://digitalcommons.fiu.edu/etd/173.
Full textAbstract:
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.
12
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.
Full text
13
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.
Full textAbstract:
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.
14
SANTHANAM, LAKSHMI. "Integrated Security Architecture for Wireless Mesh Networks." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1202846575.
Full text
15
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.
Full textAbstract:
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.
16
Munawar, Mohammad Ahmad. "Multi-interface Multi-channel wireless mesh networks." Thesis, University of Waterloo, 2004. http://hdl.handle.net/10012/875.
Full textAbstract:
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.
17
Zhang, Zhenxia. "Handoff Management Schemes in Wireless Mesh Networks." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23073.
Full textAbstract:
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.
18
Baumann, Rainer. "Building scalable and robust wireless mesh networks." Aachen Shaker, 2007. http://e-collection.ethbib.ethz.ch/view/eth:29857?q=Baumann%20mesh.
Full text
19
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.
Full textAbstract:
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.
20
Nicholas, Paul J. "Optimal transmitter placement in wireless mesh networks." Thesis, Monterey, Calif. : Naval Postgraduate School, 2009. http://handle.dtic.mil/100.2/ADA501886.
Full textAbstract:
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.
21
Wang, Peng. "Throughput optimization of urban wireless mesh networks." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 196 p, 2009. http://proquest.umi.com/pqdweb?did=1833647421&sid=6&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Full text
22
Lee, Richard Lloyd. "Feasibility of TCP for Wireless Mesh Networks." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/2973.
Full textAbstract:
When used in a wireless mesh network, TCP has shortcomings in the areas of throughput and fairness among traffic flows. Several methods have been proposed to deal with TCP's weakness in a wireless mesh, but most have been evaluated with simulations rather than experimentally. We evaluate several major enhancements to TCP – pacing, conservative windows, and delayed ACKs – to determine whether they improve performance or fairness in a mesh network operating in the BYU Computer Science building. We also draw conclusions about the effectiveness of wireless network simulators based on the accuracy of reported simulation results.
23
Nawaf, Liqaa. "Optimizing infrastructure placement in Wireless Mesh Networks." Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/100966/.
Full textAbstract:
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.
24
Naghavi, Nika. "Call admission control in wireless mesh networks." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/call-admission-control-in-wireless-mesh-networks(01d122ee-b6fe-4baa-b78c-9f5093136956).html.
Full textAbstract:
Efficiency in managing scarce wireless resources has been a major design obstacle in wireless mobile networks since its advent. A large body of work has been published on the subject in relation to the first two generation and third generation (3G) of wireless networks. However, these solutions are not readily applicable to the future IP based multi-hop wireless networks. Increased trend in the number of users accessing multimedia rich traffic, and the impacts of mobility management support mechanisms alongside the shared nature of backhaul nodes demand exploration of new avenues of resource management policies. In this thesis a set of schemes are proposed to address the issue of Call Admission Control (CAC) in future multi-hop IP based mobile networks. The first scheme is based on a joint CAC and route assignment design mechanism in Wireless Mesh Networks (WMNs) environment, addressing issues such as pricing policies, wireless resource constraints of the access and backhaul links as well as maximising network provider's revenue. Study's focus is then shifted towards CAC design in Mobility Agent (MA) based Proxy Mobile IPv6 (PMIPv6) networks. A novel class-based CAC mechanism was proposed with the aim of eliminating bottleneck effect at the MAs. To further improve the overall capacity of the network, in conjunction with the proposed CAC mechanism, a modified version of a previously proposed Route Optimisation (RO) scheme is implemented. The performance of the proposed schemes is investigated and analysed through extensive simulations. Comparative studies are then carried out to examine the network provider's total revenue gain in WMNs environment, total blocking probability and per class blocking probability in PMIPv6 networks.
25
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.
Full textAbstract:
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.
26
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.
Full textAbstract:
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.
27
Zhao, Rui. "Mesh distributed coordination function for efficient wireless Mesh networks supporting QoS /." Aachen : Mainz, 2007. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016149899&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Full text
28
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.
Full text
29
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.
Full text
30
Hällström, Magnus. "Strömmande video i trådlösa mesh nätverk : Streaming video in wireless mesh networks." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-89016.
Full textAbstract:
This document’s content is the final report of the master´s dissertation Magnus Hällström did during springtime of year 2013. The dissertation’s subject is 802.11s wireless mesh networks with streaming video as a focus point. During the dissertation a wireless mesh network was set up with different attached cameras for streaming video. A sun panel solution was also tested with the goal of creating a package with a self-configuring network node streaming video, powered by nothing but solar energy.
31
Ronasi, Keivan. "Resource allocation and scheduling in wireless mesh networks." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42751.
Full textAbstract:
The unreliability of wireless mesh networks creates challenge in designing high performance wireless networks in terms of network throughput, end-to-end delay, and fairness provisioning. In this thesis, the goal is to improve the network performance in terms of these metrics. We explore several techniques such as multipath routing, channel coding, network coding, and interference alignment. We consider resource allocation both in terms of average data rate provisioning and scheduling policies in a time slot basis.
First, we propose data rate and channel code rate allocation algorithms for networks with multiple paths to maximize the network throughput while all users can fairly exploit the network resources. We study the effect of adaptive and non-adaptive channel coding schemes. We also consider the end-to-end delay that each network flow experiences for data transmission. For that purpose, we formulate the problem of decreasing the end-to-end delay for network flows while improving the network throughput. Simulation results show that we can decrease the delay at the cost of a slight decrease in network throughput. We also formulate a data rate allocation problem in networks with network coding. Simulation results show that considering link reliabilities in the network coding design dramatically increases the network performance.
Data rate allocation algorithms provide the average data rates at which the source must transmit data. They do not determine scheduling on a time slot basis. To address that, we consider transmission scheduling in wireless networks. We also compare the suggested algorithm with a centralized optimal data rate allocation algorithm to verify that our algorithm follows the optimal solution. Through simulations, we show that fairness provisioning leads to higher network performance. We show that the suggested algorithm outperforms the current algorithms in the literature in terms of both network throughput and fairness provisioning.
Finally, we consider transmission scheduling in wireless multi-input multi-output (MIMO) systems. We formulate the problem of joint scheduling, interference alignment, and admission control in those networks and use Lyapunov stability theory to solve it. We also develop a heuristic approach to solve the problem in a semi-distributed manner.
32
Pries, Jan Rastin. "Performance optimization of wireless infrastructure and mesh networks." Doctoral thesis, Würzburg Inst. für Informatik, Lehrstuhl für Verteilte Systeme, 2010. http://d-nb.info/1000629171/34.
Full text
33
Panmin, Ye, and Yong. "Distributed Cross-layer Monitoring in Wireless Mesh Networks." Thesis, Karlstad University, Karlstad University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-4615.
Full text
34
Ye, Panming, and Yong Zhou. "Distributed Cross-layer Monitoring in Wireless Mesh Networks." Thesis, Karlstad University, Karlstad University, Karlstad University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-4617.
Full textAbstract:
Wireless mesh networks has rapid development over the last few years. However, due to properties such as distributed infrastructure and interference, which strongly affect the performance of wireless mesh networks, developing technology has to face the challenge of architecture and protocol design issues. Traditional layered protocols do not function efficiently in multi-hop wireless environments. To get deeper understanding on interaction of the layered protocols and optimize the performance of wireless mesh network, more recent researches are focusing on cross-layer measurement schemes and cross-layer protocol design. The goal of this project is to implement a distributed monitoring mechanism for IEEE802.11 based wireless mesh networks. This module is event-based and has modular structure that makes it flexible to be extended. This project results a novel Cross-Layer Monitoring Module, CLMM, which is a prototype that monitors each layer of the nodes locally and dynamically, calculates the average values of the metrics, compares these values with thresholds and handles the cross-layer messages of each node. The CLMM also has a routing module structure that can be extended to distribute the metrics to its neighbors.
35
Bayer, Nico. "Scheduling mechanisms for carrier-grade wireless mesh networks." Thesis, City University London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511868.
Full text
36
Wang, Xia. "A systematic security approach in wireless mesh networks." [Ames, Iowa : Iowa State University], 2009.
Find full text
37
Mashraqi, Aisha Mousa. "Throughput optimisation in multi-channel Wireless Mesh Networks." Thesis, University of Leicester, 2017. http://hdl.handle.net/2381/40810.
Full textAbstract:
Wireless Mesh Networks (WMNs) are becoming common due to the features provided, especially the low cost and self-configuration ability. In WMNs, the data traffic is transmitted through intermediate nodes. With the nature of wireless networks, forwarding (routing) the data from the senders to the destinations and managing the network resources efficiently are challenging. There are various reasons that affect the network performance especially the throughput reduction such as signal interference, mobility and congestion. The focus of this research is to improve the throughput in the multi-channel wireless mesh networks from two perspectives. The first issue considered in this work is selecting a path with the maximum available bandwidth and low signal interference to transmit data from the source to the destination. Thus, we design two routing metrics, the Expected Transmission Time with Queueing (ETTQ) and the Delay and Interference Aware Metric (DIAM), that consider the intra-flow interference, inter-flow interference and delay. The simulation results of these routing metrics by the Network Simulator (NS2) demonstrate that the DIAM metric can estimate the intra-flow interference, inter-flow interference and delay of a link and then select the path efficiently. The second problem that has been addressed to improve the network throughput is controlling the network congestion. In this work, we address the issue of packet drops in the Interface Queue (IFQ) due to the node congestion. We solve this issue by reducing the number of dropped packets at IFQ by allocating the flow rate from the solution of a linear program (LP). The simulations using NS2 have shown that the LP-based flow rate improves the network throughput in chain networks. In addition, with the complex networks, traffic rate adjustments alone are not sufficient and we propose a simple forwarding delay scheme for the Ad Hoc On-Demand Distance Vector protocol with Forwarding delay (AODV-F) with DIAM routing metric that reduces node congestion and improves throughput. The forwarding delay scheme has also been evaluated using NS2. Moreover, the LP adjusted flow rate and the forwarding delay address the issue of maximising the flow fairness as the results have demonstrated.
38
Santos, Ricardo. "5G Backhauling with Software-defined Wireless Mesh Networks." Licentiate thesis, Karlstads universitet, Institutionen för matematik och datavetenskap (from 2013), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-69437.
Full textAbstract:
Current technological advances have caused an exponential growth of the number of mobile Internet-connected devices, along with their respective traffic demands. To cope with this increase of traffic demands, fifth generation (5G) network architectures will need to provide multi-gigabit capacity at the access base stations (BSs), through the deployment of ultra-dense small cells (SCs) operating with millimeter-wave (mmWave) frequencies, e.g. 60 GHz. To connect the BSs to the core network, a robust and high capacity backhaul infrastructure is required. As it is unfeasible to connect all the SCs through optical fiber links, a solution for the future 5G backhaul relies on the usage of mmWave frequencies to interconnect the SCs, forming multi-hop wireless mesh topologies. In this thesis, we explore the application of the Software-defined Networking (SDN) paradigm for the management of a SC wireless backhaul. With SDN, the data and control planes are separated and the network management is done by a centralized controller entity that has a global network view. To that end, we provide multiple contributions. Firstly, we provide an SDN-based architecture to manage SC backhaul networks, which include an out-of-band Long Term Evolution (LTE) control channel and where we consider aspects such as energy efficiency, resiliency and flexible backhaul operation. Secondly, we demonstrate the benefit of the wireless backhaul configuration using the SDN controller, which can be used to improve the wireless resource allocation and provide resiliency mechanisms in the network. Finally, we investigate how a SC mesh backhaul can be optimally reconfigured between different topologies, focusing on minimizing the network disruption during the reconfiguration.The growth of mobile devices, along with their traffic demands, is expected to saturate the current mobile networks soon. To cope with such demand increase, fifth generation (5G) network architectures will need to provide multi-gigabit capacity at the access level, through the deployment of a massive amount of ultra-dense small cells (SCs). To connect the access and core networks, a robust and high capacity backhaul is required. To that end, mmWave links that operate at e.g. 60 GHz, can be used to interconnect the SCs, forming multi-hop wireless mesh topologies. In this thesis, we study the application of the Software-defined Networking (SDN) paradigm for the management of a SC wireless backhaul. Firstly, we provide an SDN-based architecture to manage SC backhaul networks, which includes an out-of-band control channel and where we consider aspects such as energy efficiency, resiliency and flexible backhaul operation. Secondly, we show the benefits of the wireless backhaul configuration using the SDN controller, which can be used to improve the wireless resource allocation and provide network resiliency. Finally, we investigate how a SC mesh backhaul can be optimally reconfigured between different topologies, while minimizing the network disruption during the reconfiguration.
39
Nahle, Salim. "Algorithms for capacity enhancement in wireless mesh networks." Paris 6, 2009. http://www.theses.fr/2009PA066523.
Full textAbstract:
Dans cette these on étudie le problème d'équité dans les réseaux maillés sans fil basé sur la technologie Wi-Fi. On propose un algorithme distribué pour améliorer l'équité et la capacité des réseaux qui est basé sur l’utilisation d’une deuxième file d’attente par nœud dédié pour stocker les paquets des autres nœuds. De plus, il change les paramètres des contentions inversement proportionnels aux débits équitables calculés, en se basant sur le ‘weighted contention graphs’. Dans la deuxième partie de cette these, On propose des algorithmes de routage et d'ordonnancement pour les réseaux maillés WiMAX dans les deux cas: un seul canal ou plusieurs. On montre par simulation l’efficacité de ces algorithmes. Enfin, on propose des algorithmes de placement des nœuds dans un réseau maillé sans fil WIMAX, dont le but est de minimiser le nombre de stations nécessaires pour assurer une couverture totale d’un itinéraire pour un débit donné.
40
Farsi, Abdelhak. "Planning and resource allocation for wireless mesh networks." Paris 13, 2012. http://scbd-sto.univ-paris13.fr/intranet/edgalilee_th_2012_farsi.pdf.
Full textAbstract:
Wireless mesh networks (WMNs) have emerged as a key technology for next generationwireless networks, showing rapid progress and inspiring numerous applications. In this thesis we emphasize on the planning and resource allocation in WMN. The work can be divided in three parts. In the first part, we investigate the problem of designing the access tier network. We aim at minimizing the installation cost, and maximizing the nominal throughput to offer to each user while minimizing the interference. We propose to deal with this multi-objective problem using two approaches. In the first approach we divide the access tier network planning issue into two problems: (1) the mesh router placement problem and (2) the frequency assignment problem. To deal with the mesh router positioning problem, we propose two strategies namely the Markov Cluster-Integer Linear Programming (MCLILP) and the Disk Covering algorithms. However, to resolve the frequency assignment problem, we propose to reduce the interference using the three algorithms: Predefined frequency Vector Approach (PFVA), Least-Interfering Channel Search (LICS) and the TPsbased Least Interfering Channel Search (TPs-LICS). We propose a second approach dealing jointly with both problems of mesh router positioning and channel assignment, namely the Three-Phase Heuristic Algorithm forWLAN planning (TPHA). This novel fast and scalable heuristic based on the potential field approach. In the second part, we deal with the backhaul topology design problem. This latter involves the following two issues: the backhaul topology formation problem and the capacity assignment problem. To overcome the complexity of this global problem, we propose the Backhaul Topology Formation Algorithm (BTFA) to solve the problem of topology formation while maximizing the capacity. However, we use an iterative-based Weighted Max-Min Fair Capacity Allocation algorithm to deal with a fair capacity assignment. In the third part, we deal with the dimensioning problem (or resource allocation) in mesh networks. We consider two different access technologies at the access tier: connectionless communication mode and connection-oriented communication mode. We propose a dimensioning methodology for each assumed technology in order to satisfy the objectives of maximizing the capacity at the backhaul tier and sharing it in a weighted max-min fair manner among all mesh routers. We evaluate the performance of our propositions and show their effectiveness by comparing them to the exact solutionLes réseaux maillés sans fils (Wireless Mesh Networks) sont apparus comme une technologie phare pour le développement des réseaux sans fils de nouvelle génération, subissant un développement rapide et inspirant un certain nombre d’applications. Dans cette thèses, on se focalise sur la planification et l’allocation de ressources dans WMN. Ce travail est divisé en trois volets. Dans le premier volet, nous traitons le problème de planification du réseau dorsal. Nous nous intéressons à la minimisation du coût d’installation, et la maximisation du débit nominal à offrir à chaque utilisateur, tout en minimisant l’interférence. Nous proposons de traiter ce problème multiobjectif en utilisant deux approches. Dans la première approche, nous définissons le problème de planification du réseau d’accès comme étant : (1) problème du positionnement de routeurs mesh et (2) problème d’affectation de canaux. Afin de résoudre le problème du positionnement des routeurs mesh, nous avons proposé deux stratégies : à savoir l’algorithme de Markov Cluster-Integer Linear Programming (MCLILP) et l’algorithme de disques couvrants. Par ailleurs, nous avons résolu le problème d’affectation de canaux par la proposition de trois algorithmes : Predefined frequency Vector Approach (PFVA), Least-Interfering Channel Search (LICS) and the TPsbased Least Interfering Channel Search (TPs-LICS). Ensuite, nous avons proposé une deuxième approche appelée Three-Phase Heuristic Algorithm for WLAN planning (TPHA). Notre deuxième approche permet d’optimiser conjointement les deux problèmes de positionnement de routeurs mesh et d’affectation de canaux. Cette nouvelle heuristique, rapide et évolutive, inspirée du domaine de la robotique, se base sur l’approche du champ de potentiel. Dans le deuxième volet, nous nous focalisons sur le problème de planification du réseau dorsal. Ce dernier, est défini comme étant : la formation de la topologie du réseau dorsal et l’affectation de sa capacité. Etant donné que la planification du réseau dorsal est un problème complexe, nous avons proposé une heuristique en deux phases. La première phase consiste en la formation de topologie en choisissant les liens qui maximisent la capacité totale du réseau dorsal. Tandis que la deuxième phase, permet le partage de la capacité du réseau dorsal entre les différents routeurs mesh selon l’équité Max-Min. Dans le troisième volet, nous nous intéressons au problème du dimensionnement (allocation de ressources) du réseau mesh à deux niveaux. Nous supposons deux technologies d’accès différentes : mode de communication non connecté et le mode connecté. Nous proposons une méthodologie de dimensionnement pour chaque mode de communication afin de satisfaire les deux objectifs de maximisation de la capacité et de la partager entre tous les routeurs mesh selon la stratégie d’équité Max-Min pondérée. Finalement, les algorithmes et modèles proposés ont été évalués en comparant leurs résultats à la solution exacte
41
Li, Xiaoguang. "Channel Switching Control Policy for Wireless Mesh Networks." Master's thesis, Temple University Libraries, 2012. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/164788.
Full textAbstract:
Computer and Information ScienceM.S.
Dynamic channel assignment algorithms allow wireless nodes to switch channels when their traffic loads exceed certain thresholds. These thresholds represent estimations of their throughput capacities. Unfortunately, the threshold estimation may not be accurate due to co-channel interference (CCI) and adjacent-channel interference (ACI), especially with high traffic loads in dense networks. When the link capacity is over-estimated, these channel assignment algorithms are not effective. This is because channel switch is not triggered even with overloaded data traffic and the link quality decreases significantly as the channel is overloaded. When the link capacity is under-estimated, the link is under utilized. Moreover, when link traffic load increases from time to time, channel switch occurs frequently. Such frequent channel switches increase latency and degrade throughput, and can even cause network wide channel oscillations. In this paper, we propose a novel threshold-based control system, called \emph{balanced control system} (BCS). The proposed threshold-based control policy consist of deciding, according to the real time traffic load and interference, whether to switch to another channel,{which channel should be switched to and how to perform the switch. Our control model is based on a fuzzy logic control. The threshold which assists to make the channel switch decisions, could be deduced dynamically according to the real-time traffic of each node. We also design a novel dynamic channel assignment scheme, which is used for the selection of the new channel. The channel switch scheduler is provided to perform channel-switch processing for sender and receiver over enhanced routing protocols. We implement our system in NS2, and the simulation results show that with our proposed system, the performance improves by 12.3\%-72.8\% in throughput and reduces 23.2\%-52.3\% in latency.
Temple University--Theses
42
Osękowska, Ewa A. "Performance Evaluation of Wireless Mesh Networks Routing Protocols." Thesis, Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3712.
Full textAbstract:
The tremendous growth in the development of wireless networking techniques attracts growing attention to this research area. The ease of development, low installation and maintenance costs and self healing abilities are some of the qualities that make the multi-hop wireless mesh network a promising solution for both - rural and urban environments. Examining the performance of such a network, depending on the external conditions and the applied routing protocol, is the main aim of this research. It is addressed in an empirical way, by performing repetitive multistage network simulations followed by a systematic analysis and a discussion. This research work resulted in the implementation of the experiment and analysis tools, a comprehensive assessment of the simulated routing protocols - DSDV, AODV, OLSR and HWMP, and numerous observations concerning the simulation tool. Among the major findings are: the suitability of protocols for wireless mesh networks, the comparison of rural and urban environments and the large impact of conditions such as propagation, density and scale of topology on the network performance. An unexpected but valuable outcome is the critical review of the ns network simulator.Mobile number: +48 660144055
43
Bagale, Jiva Nath. "On the performance of emerging wireless mesh networks." Thesis, University of West London, 2015. https://repository.uwl.ac.uk/id/eprint/1279/.
Full textAbstract:
Wireless networks are increasingly used within pervasive computing. The recent development of low-cost sensors coupled with the decline in prices of embedded hardware and improvements in low-power low-rate wireless networks has made them ubiquitous. The sensors are becoming smaller and smarter enabling them to be embedded inside tiny hardware. They are already being used in various areas such as health care, industrial automation and environment monitoring. Thus, the data to be communicated can include room temperature, heart beat, user’s activities or seismic events. Such networks have been deployed in wide range areas and various levels of scale. The deployment can include only a couple of sensors inside human body or hundreds of sensors monitoring the environment. The sensors are capable of generating a huge amount of information when data is sensed regularly. The information has to be communicated to a central node in the sensor network or to the Internet. The sensor may be connected directly to the central node but it may also be connected via other sensor nodes acting as intermediate routers/forwarders. The bandwidth of a typical wireless sensor network is already small and the use of forwarders to pass the data to the central node decreases the network capacity even further. Wireless networks consist of high packet loss ratio along with the low network bandwidth. The data transfer time from the sensor nodes to the central node increases with network size. Thus it becomes challenging to regularly communicate the sensed data especially when the network grows in size. Due to this problem, it is very difficult to create a scalable sensor network which can regularly communicate sensor data. The problem can be tackled either by improving the available network bandwidth or by reducing the amount of data communicated in the network. It is not possible to improve the network bandwidth as power limitation on the devices restricts the use of faster network standards. Also it is not acceptable to reduce the quality of the sensed data leading to loss of information before communication. However the data can be modified without losing any information using compression techniques and the processing power of embedded devices are improving to make it possible. In this research, the challenges and impacts of data compression on embedded devices is studied with an aim to improve the network performance and the scalability of sensor networks. In order to evaluate this, firstly messaging protocols which are suitable for embedded devices are studied and a messaging model to communicate sensor data is determined. Then data compression techniques which can be implemented on devices with limited resources and are suitable to compress typical sensor data are studied. Although compression can reduce the amount of data to be communicated over a wireless network, the time and energy costs of the process must be considered to justify the benefits. In other words, the combined compression and data transfer time must also be smaller than the uncompressed data transfer time. Also the compression and data transfer process must consume less energy than the uncompressed data transfer process. The network communication is known to be more expensive than the on-device computation in terms of energy consumption. A data sharing system is created to study the time and energy consumption trade-off of compression techniques. A mathematical model is also used to study the impact of compression on the overall network performance of various scale of sensor networks.
44
Nawrath, Thomas. "P2P-based Mobility Management for Heterogeneous Wireless Networks and Mesh Networks." Universitätsbibliothek Chemnitz, 2006. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200601065.
Full textAbstract:
Today Moblity Management is one of the most important
tasks that need to be accomplished to secure availability
and performance of communication between people. This paper
explains how moblity management is currently structured
and what algorithms and approaches from Peer-To-Peer
technology could be used to increase availability and
performance.
45
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.
Full textAbstract:
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.
46
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.
Full textAbstract:
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.
47
Chan, Michael Chi Fung. "MOLE : multi-hop object location in wireless mesh networks /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?CSED%202008%20CHAN.
Full text
48
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.
Full textAbstract:
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.
49
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.
Full textAbstract:
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.
50
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.
Full textAbstract:
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.