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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

OpenFlow Switching Performance using Network Simulator - 3

Sriram Prashanth, Naguru January 2016 (has links)
Context. In the present network inventive world, there is a quick expansion of switches and protocols, which are used to cope up with the increase in customer requirement in the networking. With increasing demand for higher bandwidths and lower latency and to meet these requirements new network paths are introduced. To reduce network load in present switching network, development of new innovative switching is required. These required results can be achieved by Software Define Network or Traditional layer-3 technologies.Objectives. In this thesis, the end to end (e2e) transmission performance of OpenFlow and Layer-3 switches and their dynamic characteristics are investigated using network simulation.Methods. To replicate real life network topology and evaluate e2e transmission performance, a simulation based test-bed is implemented for both OpenFlow switch and layer-3 switch. The test beds are implemented using Network Simulator-3 (NS3). A two-tire network topology is designed with specified components for performance evaluation.Results. The performance metrics like throughput, average delay, simulation time and Packet Delivery Ratio (PDR) are measured, results are analyzed statistically and are compared. The behavior of network traffic in both the topologies are understood using NS-3 and explained further in the thesis.Conclusions. The analytical and statistical results from simulation show that OpenFlow switching performs relatively better than layer-3 switching.
2

An?lise de desempenho baseada em simula??o de redes WirelessHART

Nobre, Marcelo Henrique Ramalho 05 August 2012 (has links)
Made available in DSpace on 2014-12-17T14:55:51Z (GMT). No. of bitstreams: 1 MarceloHRN_DISSERT.pdf: 1910960 bytes, checksum: 696b69a0c65216fcf9b33e58073b32ab (MD5) Previous issue date: 2012-08-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This dissertation describes the implementation of a WirelessHART networks simulation module for the Network Simulator 3, aiming for the acceptance of both on the present context of networks research and industry. For validating the module were imeplemented tests for attenuation, packet error rate, information transfer success rate and battery duration per station / Esta disserta??o descreve a implementa??o de um m?dulo de simula??o para redes WirelessHART, utilizando o simulador de redes Network Simulator 3, tendo em vista a aceita??o que ambos possuem no atual contexto de pesquisa e na ind?stria. Para valida??o do m?dulo foram implementados testes quanto a atenua??o dos sinais transmitidos, probabilidade de perda pacotes (Packet Error Rate PER), probabilidade de que uma informa??o produzida seja recebida no destino e dura??o da bateria nas esta??es
3

Study on Energy saving in Wireless Mesh Networks Using Network Simulator - 3

Sravani, Kancharla January 2016 (has links)
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.
4

Contribui??es em escalonamento e an?lise de desempenho de redes WirelessHART

Nobre, Marcelo Henrique Ramalho 23 November 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-06T19:34:30Z No. of bitstreams: 1 MarceloHenriqueRamalhoNobre_TESE.pdf: 4355071 bytes, checksum: 05cf1b490e598685ec4e7b682423a8d9 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-06T22:04:01Z (GMT) No. of bitstreams: 1 MarceloHenriqueRamalhoNobre_TESE.pdf: 4355071 bytes, checksum: 05cf1b490e598685ec4e7b682423a8d9 (MD5) / Made available in DSpace on 2016-07-06T22:04:01Z (GMT). No. of bitstreams: 1 MarceloHenriqueRamalhoNobre_TESE.pdf: 4355071 bytes, checksum: 05cf1b490e598685ec4e7b682423a8d9 (MD5) Previous issue date: 2015-11-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A comunica??o sem fios ? uma tend?ncia no ambiente industrial atualmente e nessa tend?ncia temos o WirelessHART como uma das principais tecnologias. Com essa situa??o, ? natural que melhorias no desempenho sejam buscadas e um dos principais caminhos para isso passa pelo desenvolvimento de algoritmos de escalonamento e roteamento. Nesta tese ? apresentado uma revis?o da literatura sobre as principais solu??es em escalonamento e roteamento desenvolvidas especificamente para a tecnologia WirelessHART. Al?m disso prop?e um novo Algoritmo de escalonamento chamando Escalonamento Flow que visa melhorar aspectos de flexibilidade e de utiliza??o do superframe. Para prop?sitos de valida??o, ? desenvolvido e utilizado um m?dulo de simula??o para o Network Simulator 3 (NS-3) que modela aspectos como posicionamento, atenua??o de sinal e consumo de energia al?m de prover simula??es mais exatas por meio de configura??es de erro individuais para cada link. Este m?dulo tamb?m possibilita a gera??o do superframe de escalonamento a partir do grafo de roteamento utilizando os algoritmos Flow e Han. Para a valida??o do novo algoritmo s?o realizados experimentos comparativos entre o algoritmo Han e algoritmo Flow, avaliando crit?rios de aloca??o de links, delay e taxa de ocupa??o de superframe. Para valida??o da camada f?sica do m?dulo de simula??o, o escalonamento e o roteamento s?o configurados estaticamente e s?o desenvolvidos experimentos de confiabilidade e consumo de energia com topologias validadas na literatura e com varia??es de probabilidades de erro. / Wireless Communication is a trend in the industrial environment nowadays and on this trend, we can highlight the WirelessHART technology. In this situation, it is natural the search for new improvements in the technology and such improvements can be related directly to the routing and scheduling algorithms. In the present thesis, we present a literature review about the main specific solutions for Routing and scheduling for WirelessHART. The thesis also proposes a new scheduling algorithm called Flow Scheduling that intends to improve superframe utilization and flexibility aspects. For validation purposes, we develop a simulation module for the Network Simulator 3 (NS-3) that models aspects like positioning, signal attenuation and energy consumption and provides an link individual error configuration. The module also allows the creation of the scheduling superframe using the Flow and Han Algorithms. In order to validate the new algorithms, we execute a series of comparative tests and evaluate the algorithms performance for link allocation, delay and superframe occupation. In order to validate the physical layer of the simulation module, we statically configure the routing and scheduling aspects and perform reliability and energy consumption tests using various literature topologies and error probabilities.
5

Modelování mechanizmů vícenásobného přístupu do mobilní sítě / Modelling of Mechanisms for Multiple Access to Mobile Network

Tinka, Zdeněk January 2014 (has links)
The diploma thesis „Mechanisms modelling of multi access into mobile wireless network“ is focusing the wireless network. The diploma thesis contains basic network topology of wireless standard 802.11g and utilizes key identificators of mobile node in dependency on the distance and collision controlling function for simulation purposes. In the next part of this thesis is created LTE mobile network topology, which serves for finding key identificators. In the last part is created offload topology containing both - 802.11g and LTE network. As the result are implemented offloading algorithms, which ensure data traffic switching based on comparing 802.11g and LTE key identificators. Automatically generated and shown figures providing the key statistics are the main output of this thesis.
6

Implementace a vyhodnocení komunikační technologie LTE Cat-M1 v simulačním prostředí NS-3 / Implementation of the LTE Cat-M1 Communication Technology Using the Network Simulator 3

Maslák, Roman January 2021 (has links)
The Diploma work deals with the implementation of LTE Cat-M technology in the simulation tool Network Simulator 3 (NS-3). The work describe LPWA technologies and their use cases. In first are described the main parts of the Internet of Things (IoT) and Machine-to-Machine (M2M) communication. Subsequently are described and defined the most used technologies in LPWA networks. Technologies which are used in the LPWA networks are Sigfox, LoRaWAN, Narrowband IoT (NB-IoT) and Long Term Evolution for Machines (LTE Cat-M), where LTE Cat-M technology is described in more details. Simulations are simulated in simulation tool NS-3 and use LENA module. In NS 3 tool are simulated Simulations, which give us informations of Network state according to different Network set up. At the end are done changes of Radio Resource Control (RRC) states in NS-3 tool. These changes are required for correct implementation LTE Cat-M technology in NS-3 tool. Then we are able to simulate simulations, which meet to definition of LTE Cat-M technology.
7

Analýza a predikce datového provozu v mobilní ad hoc síti / Analysis and prediction of data traffic in mobile ad hoc network

Konečný, Daniel January 2014 (has links)
The diploma thesis „Analysis and prediction of data traffic in mobile Ad Hoc network“ focuses on the radio propagation models of services in MANET (Mobile Ad-hoc) networks. It describes MANET networks and covers the theoretical analysis of routing protocols, radio wave propagation and propagation models of simulation enviroment NS-3 (Network Simulator 3). Furthermore, there is processed the creation process of model MANET networks with the routing protocol AODV (Ad Hoc On Demand Distance Vector) in the simulation environment NS-3. For analysis purposes there were implemented new functions to capture value of SNR (Signal to Noise Ratio) and throughtput. For this reason a physical layer of one of NS-3 model was modified. As an result there is a simulation build that compared several number of propagaion models.

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