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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Samoorganizující se sítě typu MESH / Self-organizing MESH wireless networks

Němec, Petr January 2009 (has links)
This master thesis deals with self organized Mesh network. It describes routing and particular routing protocols, which are used in these networks. The thesis deals with Mesh network QoS assurance. Analysis and theoretical background of Mesh networks, routing and router protocols are included in the first chapter. Basic models of assuring Quality of Service are also described. Those are Best Effort, IntServ and DiffServ. Second chapter describes the devices used in the specific Mesh network topology - Trospos 5210 MetroMesh router produced by Motorola Canopy. Basic settings and properties required to establish a Mesh network are described. Next part of the thesis is the design implementation, which involves creation and configuration of the Mesh Network. Network configuration consisting of two Gateway points and afterwards behaviors of the network in a steady state versus one gate failure are compared. Furthermore, implementation of QoS according to components that support two types of QoS assurance regarding type of bandwidth reservation and defined traffic classes. In conclusion, the thesis describes measurement methods of QoS parameters for chosen applications, evaluation and comparison of measurement results for both types of Quality of Service assurance.
2

A Hybrid Routing Protocol For Communications Among Nodes Withhigh Relative Speed In Wireless Mesh Networks

Peppas, Nikolaos 01 January 2007 (has links)
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.
3

Routing algorithms for large scale wireless sensor networks

Nittala Venkata, Lakshmana Prasanth 17 February 2005 (has links)
Routing in sensor networks is a challenging issue due to inherent constraints such as power, memory, and CPU processing capabilities. In this thesis, we assume an All to All communication mode in an N × N grid sensor network. We explore routing algorithms which load balance the network without compromising the shortest paths constrain. We analyzed the Servetto method and studied two routing strategies, namely Horizontal-Vertical routing and Zigzag routing. The problem is divided into two scenarios, one being the static case (without failed nodes), and the other being the dynamic case (with failed nodes). In static network case, we derived mathematical formulae representing the maximum and minimum loads on a sensor grid, when specific routing strategies are employed. We show improvement in performance in load balancing of the grid by using Horizontal-Vertical method instead of the existing Servetto method. In the dynamic network scenario, we compare the performance of routing strategies with respect to probability of failure of nodes in the grid network. We derived the formulae for the success-ratio, in specific strategies, when nodes fail with a probability of p in a predefined source-destination pair communication. We show that the Servetto method does not perform well in both scenarios. In addition, Hybrid strategy proposed does not perform well compared to the studied strategies. We support the derived formulae and the performance of the routing strategies with extensive simulations.

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