This thesis presents an investigation of how to extend the reach of a Bluetooth personal area network by introducing the concept of Bluetooth Hotspots. Currently two Bluetooth devices cannot communicate with each other unless they are within radio range, since Bluetooth is designed as a cable-replacement technology for wireless communications over short ranges. An investigation was done into the feasibility of creating Bluetooth hotspots that allow distant Bluetooth devices to communicate with each other by transporting their communications between these hotspots via an alternative network infrastructure such as an IP network. Two approaches were investigated, masquerading of remote devices by the local hotspot to allow seamless communications and proxying services on remote devices by providing them on a local hotspot using a distributed service discovery database. The latter approach was used to develop applications capable of transporting Bluetooth’s RFCOMM and L2CAP protocols. Quantitative tests were performed to establish the throughput performance and latency of these transport applications. Furthermore, a number of selected Bluetooth services were tested which lead us to conclude that most data-based protocols can be transported by the system.

The use of Network Telescope systems has become increasingly popular amongst security researchers in recent years. This study provides a framework for the utilisation of this data. The research is based on a primary dataset of 40 million events spanning 50 months collected using a small (/24) passive network telescope located in African IP space. This research presents a number of differing ways in which the data can be analysed ranging from low level protocol based analysis to higher level analysis at the geopolitical and network topology level. Anomalous traffic and illustrative anecdotes are explored in detail and highlighted. A discussion relating to bogon traffic observed is also presented. Two novel visualisation tools are presented, which were developed to aid in the analysis of large network telescope datasets. The first is a three-dimensional visualisation tool which allows for live, near-realtime analysis, and the second is a two-dimensional fractal based plotting scheme which allows for plots of the entire IPv4 address space to be produced, and manipulated. Using the techniques and tools developed for the analysis of this dataset, a detailed analysis of traffic recorded as destined for port 445/tcp is presented. This includes the evaluation of traffic surrounding the outbreak of the Conficker worm in November 2008. A number of metrics relating to the description and quantification of network telescope configuration and the resultant traffic captures are described, the use of which it is hoped will facilitate greater and easier collaboration among researchers utilising this network security technology. The research concludes with suggestions relating to other applications of the data and intelligence that can be extracted from network telescopes, and their use as part of an organisation’s integrated network security systems

Continuous improvements to the state of the art have made it easier to create, send and receive vast quantities of video over the Internet. Catalysed by these developments, video is now the largest, and fastest growing type of traffic on modern IP networks. In 2015, video was responsible for 70% of all traffic on the Internet, with an compound annual growth rate of 27%. On the other hand, concerns about the growing energy consumption of ICT in general, continue to rise. It is not surprising that there is a significant energy cost associated with these extensive video usage patterns. In this thesis, I examine the energy consumption of typical video configurations during decoding (playback) and encoding through empirical measurements on an experimental test-bed. I then make extrapolations to a global scale to show the opportunity for significant energy savings, achievable by simple modifications to these video configurations. Based on insights gained from these measurements, I propose a novel, energy-aware Quality of Experience (QoE) metric for digital video - the Energy - Video Quality Index (EnVI). Then, I present and evaluate vEQ-benchmark, a benchmarking and measurement tool for the purpose of generating EnVI scores. The tool enables fine-grained resource-usage analyses on video playback systems, and facilitates the creation of statistical models of power usage for these systems. I propose GreenDASH, an energy-aware extension of the existing Dynamic Adaptive Streaming over HTTP standard (DASH). GreenDASH incorporates relevant energy-usage and video quality information into the existing standard. It could enable dynamic, energy-aware adaptation for video in response to energy-usage and user ‘green' preferences. I also evaluate the subjective perception of such energy-aware, adaptive video streaming by means of a user study featuring 36 participants. I examine how video may be adapted to save energy without a significant impact on the Quality of Experience of these users. In summary, this thesis highlights the significant opportunities for energy savings if Internet users gain an awareness about their energy usage, and presents a technical discussion how this can be achieved by straightforward extensions to the current state of the art.

Orientador: Helio Waldman / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-04T21:18:47Z (GMT). No. of bitstreams: 1 Magro_JulioCesar_M.pdf: 1795144 bytes, checksum: cc5adfc75b6040f36e37ce144569c2be (MD5) Previous issue date: 2005 / Resumo: Este trabalho descreve o estudo da qualidade de voz em redes IP a partir de uma revisão dos protocolos e mecanismos relativos a qualidade de serviço (QoS) e os aspectos do impacto sistêmico na presença ou ausência destes; revisão dos diversos métodos de avaliação da qualidade da voz com ênfase nos métodos automáticos (objetivos e repetitivos) para auxiliar na análise dos efeitos na voz dos diversos fatores presentes em uma rede de pacotes, tais como perda de pacote, atraso e jitter, bem como a própria codificação da voz em baixas taxas; revisão dos principais protocolos de sinalização utilizados para implementação de voz sobre IP (VoIP) ou telefonia sobre IP, evidenciando-se seus pontos fortes e fracos com relação a facilidade de implementação, extensibilidade e adequabilidade para várias aplicações de rede e qualidade de serviço (QoS) e realização de testes em redes IP simulada e experimental. O principal objetivo é a caracterização do serviço de voz em redes IP levando-se em consideração os efeitos dos fatores de rede e gateway no tempo de estabelecimento de uma chamada (conexão) e na qualidade da voz. Para simulação da rede IP foi utilizado o software Cloud da Shunra onde é possível tratar, de forma isolada, a influência da perda de pacote, do atraso fixo, do atraso variável (jitter), bem como do efeito conjunto da perda de pacote e jitter. Soluções a tais efeitos são investigadas em testes experimentais. Resultados de simulações sistêmicas são apresentados e discutidos. As degradações na voz devidas a tais efeitos são avaliadas e um método prático para solucionar é testado. Os resultados experimentais demonstram a viabilidade técnica da utilização da voz sobre IP (ou telefonia IP) pelos provedores de serviço, bem como pelas corporações privadas, podendo trafegar voz e dados em uma mesma rede convergente IP / Abstract: This work describes the study of voice quality in IP networks based on a revision of quality of service (QoS) protocols and mechanisms and aspects of the system impact associated with the presence or absence of them; revision of the diverse evaluation methods of voice quality with emphasis in the automatic methods (objective and repetitive) used to analyze the effects in the voice due to diverse factors presented in packet networks, such as packet loss, delay and jitter, as well as the proper voice coding at low rate; revision of the main protocols of signalling for implementation of voice over IP (VoIP) or IP telephony, considering its strong and weak points with regard to implementation facility, scalability and adequacy for some network applications and quality of service (QoS) and accomplishment of tests in simulated and experimental IP networks. The main objective is the characterization of voice service in IP networks taking into account the effect of the network factors in call set-up (connection) and in voice quality . For the simulation of the IP network the Shunra¿s Cloud software was used where it is possible to deal with, in isolated form, the influence of packet loss, fixed delay, delay variation ( jitter), as well as the composed effect of packet loss and jitter. Solutions to such effects are investigated in experimental tests. Results of system simulations are presented and discussed. Degradations in voice due to such effects are evaluated and a practical method to solve them is considered. The experimental results demonstrate the technical feasibility of using voice over IP (or IP telephony) by service providers, as well as private corporations being able to forward voice and data over the same converged IP network / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Orientador: Hugo Enrique Hernandez Figueroa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-05T07:05:01Z (GMT). No. of bitstreams: 1 Albuquerque_EdisondeQueiroz_D.pdf: 2450262 bytes, checksum: 1142d9b235574921d845ac5246fbe250 (MD5) Previous issue date: 2005 / Resumo: Este trabalho está baseado em uma experiência real, vivida no dia-a-dia do nosso trabalho na Empresa Brasileira de Telecomunicações S.A, EMBRATEL, quando da busca de ferramentas capazes de viabilizar o permanente treinamento dos Consultores Técnicos da empresa, localizados em diferentes partes do nosso país, em face da escassez de recursos financeiros e de tempo. Para tanto, iniciamos com uma retrospectiva histórica da Educação a Distância no mundo, seu presente e suas tendências visíveis. Depois, apresentamos uma descrição dos protocolos multicasting existentes, seguido de nossa proposta. Apresentamos, também, uma simulação usando o Simulador ns-2 de maneira a comprovar o correto funcionamento do protocolo proposto e avaliar seu desempenho. O núcleo desta tese é a proposta de um novo protocolo multicasting, elemento essencial para a otimização da rede de suporte, um imperativo para a eficiência de seu funcionamento e, principalmente, da diminuição de seu custo, tendo em vista a situação ideal de se transmitir voz e vídeo para garantir que uma aula a distância será o mais próximo possível de uma aula presencial, conforme aponta o resultado de pesquisas referenciadas no presente texto, uma vez que vídeo é uma aplicação que demanda grande largura de banda / Abstract: This work is based on a real life situation, experienced in our daily work at Empresa Brasileira de Telecomunicações S.A, EMBRATEL, when pursuing tools that would allow the continuous training of its staff of Technical Consultants. The Technical Consultants were spread all over Brasil, a country of continental dimensions. Time and cost were obstac1es to achieve the above mentioned training. This thesis starts providing a short account of the historical milestones on Distance Learning. We added considerations on the state-of-the-art and scenarios of future developments, which were drawn taking into account social and economical policies. Routing and existing multicasting protocols are described and compared with the bidirectional multicast protocol proposed in this thesis. The main purpose of this thesis is the proposal of a new Multicasting Protocol, to support a new concept on which a teacher can be a student on a different subject by taking into account that we aim a Distance Learning environment inside a corporation. The ns-2 Simulator is used to simulate the perfect operation of the proposed protocol and evaluate its performance. The use of video is mandatory in order to achieve a maximum efficiency at c1ass. The rapid switching of video transmission from the teacher to a remote student that asks a question (so that all other students spread around the country can also see who is asking) and back to the teacher is mandatory and is what motivated the development of this new Multicast Protocol / Doutorado / Telecomunicações e Telemática / Doutor em Engenharia Elétrica

Orientador: Nelson Luis Saldanha da Fonseca / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-13T20:11:45Z (GMT). No. of bitstreams: 1 Michel_NeilaFernanda_M.pdf: 1961141 bytes, checksum: f4470a332c9b5f764b7bd3b912c27db1 (MD5) Previous issue date: 2008 / Resumo: O protoloco TCP Reno começou a operar em 01 de Janeiro de 1983. Desde sua concepção, houveram expressivos avanços nas tecnologias de transmissão de dados, como a introdução de enlaces ópticos e de satélites, 'que permitem altas taxas de transmissão. O TCP Reno continua sendo o protocolo padrão na Internet. Entretanto existem inúmeras dificuldades na sua operação, que causam baixo desempenho em redes com produto banda-atraso elevado, devido ao mecanismo de atualização do tamanho da janela de congestionamento. Para superar suas deficiências, vários protocolos variantes do TCP Reno têm sido propostos com o objetivo de melhorar a utilização de recursos em redes de alta velocidade, e por esta razão são denominados "Protocolos para Redes de Alta Velocidade" . Para que as proposições de variantes do TCP levem a protocolos que operem eficientemente em redes com alto valor do produto banda-atraso, é necessário que se avalie quais variações da dinâmica do crescimento da janela de transmissão são efetivas. Nesta dissertação avalia-se um conjunto de protocolos variantes do TCP para redes de alta velocidade através de simulações. Diversas propriedades importantes para protocolos do tipo TCP são investigadas / Abstract: The importance of the Reno TCP protocol started operating in January 01 st, 1983. Since this milestone, there were expressive advances on data transmission technologies, such as those of optical fibers and satellite channels which allow high transmission rates on long distances. Reno TCP remains the Internet standard protocol. However, its operation presents several dificulties in networks with high bandwidth-delay product, producing poor performance due its window congestion mechanism. In order to overcome its deficiencies, several variants have been proposed with the aim of enhancing its utilization in high speed networks. These variants are generally called "High Speed Networks Protocols". Transmission chàracteristics, properties and performance evaluation are essencial to the identification of problems and avoidance of poor performance. In this dissertation a set of TCP variants protocols for high speed networks is evaluated. Several important properties of these protocols are investigated / Mestrado / Redes de Computadores / Mestre em Ciência da Computação

Wireless is an important part of the future and utilizing the wireless technology in project management is a great tool. This project is a messaging system designed using WAP and Java Server pages, as both of them are the technologies of the future. The project puts together a tool to help in project management made with the use of Java Server Pages and MySQL as the backend database. It uses Wireless Markup Language as the basic language for the cellular phones and the hand held wireless devices. The prototype has been modeled on project planning for power plants done by Asea Brown Boveri, Ltd.

The algorithms which control network routing are specific to the network because the algorithms are designed to take advantage of that network's topology. The "goodness" of a network includes such criteria as a simple routing algorithm and a simple routing algorithm would increase the use of the shuffle-exchange network.

The goal of this project is to create a customized web browser to facilitate the skimming of documents by offsetting the document with relevant information. This project added techniques of learning information retrieval to automate the web browsing experience to the web texturizer. The script runs on the web texturizer website; and it allows users to quickly navigate through the web page.

This work is concerned with an implementation of a software framework for usability testing. This extensive network framework and its protocol allow for integration of libraries for data collection from the basic peripherals like mouse, keyboard, camera, etc. If the protocol rules are implemented, these libraries can be platform independent. The client-server architecture allows for management of all collected data in a central database. The data in this database can be queried for evaluating the usability of applications.