TV White Spaces: A Pragmatic Approach

190 pages The editors and publisher have taken due care in preparation of this book, but make no expressed or implied warranty of any kind and assume no responsibility for errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of the use of the information contained herein. Links to websites imply neither responsibility for, nor approval of, the information contained in those other web sites on the part of ICTP. No intellectual property rights are transferred to ICTP via this book, and the authors/readers will be free to use the given material for educational purposes.  e ICTP will not transfer rights to other organizations, nor will it be used for any commercial purposes. ICTP is not to endorse or sponsor any particular commercial product, service or activity mentioned in this book. This book is released under the Attribution-NonCommercial-NoDerivatives ¦.þ International license. For more details regarding your rights to use and redistribute this work, see http://creativecommons.org/licenses/by-nc-nd/4.0/

Building Programmable Wireless Networks: An Architectural Survey

In recent times, there have been a lot of efforts for improving the ossified Internet architecture in a bid to sustain unstinted growth and innovation. A major reason for the perceived architectural ossification is the lack of ability to program the network as a system. This situation has resulted partly from historical decisions in the original Internet design which emphasized decentralized network operations through co-located data and control planes on each network device. The situation for wireless networks is no different resulting in a lot of complexity and a plethora of largely incompatible wireless technologies. The emergence of "programmable wireless networks", that allow greater flexibility, ease of management and configurability, is a step in the right direction to overcome the aforementioned shortcomings of the wireless networks. In this paper, we provide a broad overview of the architectures proposed in literature for building programmable wireless networks focusing primarily on three popular techniques, i.e., software defined networks, cognitive radio networks, and virtualized networks. This survey is a self-contained tutorial on these techniques and its applications. We also discuss the opportunities and challenges in building next-generation programmable wireless networks and identify open research issues and future research directions.Comment: 19 page

The relationship between choice of spectrum sensing device and secondary-user intrusion in database-driven cognitive radio systems

As radios in future wireless systems become more flexible and reconfigurable whilst available radio spectrum becomes scarce, the possibility of using TV White Space devices (WSD) as secondary users in the TV Broadcast Bands (without causing harmful interference to licensed incumbents) becomes ever more attractive. Cognitive Radio encompasses a number of technologies which enable adaptive self-programming of systems at different levels to provide more effective use of the increasingly congested radio spectrum. Cognitive Radio has the potential to use spectrum allocated to TV services, which is not actually being used by these services, without causing disruptive interference to licensed users by using channel selection aided by use of appropriate propagation modelling in TV White Spaces.The main purpose of this thesis is to explore the potential of the Cognitive Radio concept to provide additional bandwidth and improved efficiency to help accelerate the development and acceptance of Cognitive Radio technology. Specifically, firstly: three main classes of spectrum sensing techniques (Energy Detection, Matched Filtering and Cyclostationary Feature Detection) have compare in terms of time and spectrum resources consumed, required prior knowledge and complexity, ranking the three classes according to accuracy and performance. Secondly, investigate spectrum occupancy of the UHF TV band in the frequency range from 470 to 862 MHz by undertaking spectrum occupancy measurements in different locations around the Hull area in the UK, using two different receiver devices; a low cost Software-Defined Radio device and a laboratory-quality spectrum analyser. Thirdly, investigate the best propagation model among three propagation models (Extended-Hata, Davidson-Hata and Egli) for use in the TV band, whilst also finding the optimum terrain data resolution to use (1000, 100 or 30 m). it compares modelled results with the previously-mentioned practical measurements and then describe how such models can be integrated into a database-driven tool for Cognitive Radio channel selection within the TV White Space environment. Fourthly, create a flexible simulation system for creating a TV White Space database by using different propagation models. Finally, design a flexible system which uses a combination of Geolocation Database and Spectrum Sensing in the TV band, comparing the performance of two spectrum analysers (Agilent E4407B and Agilent EXA N9010A) with that of a low cost Software-Defined Radio in the real radio environment. The results shows that white space devices can be designed using SDRs based on the Realtek RTL2832U chip (RTL-SDR), combined with a geolocation database for identifying the primary user in the specific location in a cost-effective manner. Furthermore it is shown that improving the sensitivity of RTL-SDR will affect the accuracy and performance of the WSD

Cognitive Spectrum Management in Dynamic Cellular Environments: : A Case-Based Q-Learning Approach

This paper examines how novel cellular system architectures and intelligent spectrum management techniques can be used to play a key role in accommodating the exponentially increasing demand for mobile data capacity in the near future. A significant challenge faced by the artificial intelligence methods applied to such flexible wireless communication systems is their dynamic nature, e.g. network topologies that change over time. This paper proposes an intelligent case-based Q-learning method for dynamic spectrum access (DSA) which improves and stabilises the performance of cognitive cellular systems with dynamic topologies. The proposed approach is the combination of classical distributed Q-learning and a novel implementation of case-based reasoning which aims to facilitate a number of learning processes running in parallel. Large scale simulations of a stadium small cell network show that the proposed case-based Q-learning approach achieves a consistent improvement in the system quality of service (QoS) under dynamic and asymmetric network topology and traffic load conditions. Simulations of a secondary spectrum sharing scenario show that the cognitive cellular system that employs the proposed case-based Q-learning DSA scheme is able to accommodate a 28-fold increase in the total primary and secondary system throughput, but with no need for additional spectrum and with no degradation in the primary user QoS

Alegria: The Rise of Brazil's "Carnival of Popular Participation," Salvador da Bahia, 1950-2000s

In the second half of the twentieth century, the annual carnival in the economically depressed northeastern city of Salvador da Bahia underwent a series of transformations that brought it from relative anonymity in Brazil--where festivities in the cities of Rio de Janeiro and Recife had long been given pride of place--to the status of (inter)national showpiece in terms of cultural and entrepreneurial innovation and touristic appeal. It became a dominant factor in year-round local music production. In an era of political constraint, it appeared to embody the collective performance of multiple democracies including race and free-market consumerism. New forms of popular participation were linked to innovations in carnival that, in other national carnival sites, would have been precluded by regulation and tradition. This dissertation draws from debates and analysis in Brazil's intellectual, policy, and media spheres regarding carnival, folklore, tourism, Bahian culture, mass culture, and national identity to argue that 1) the traits of creative spontaneity and popular participation in Salvador's carnival gained prominence as both national ambivalence over "folklore" increased, and dictatorial regimes constrained political democracy; 2) the state, rather than discursively and economically controlling Salvador's carnival, has more often reacted to artistic production and market forces, its hegemony configured through strategies of support and appropriation linked to tourism and an internally amplified social ethic of alegria; and 3) media and cultural commentators have made Salvador's modern carnival a new locus for longstanding national conversations over Brazilian identity, regionalism, race, and cultural imperialism, casting its innovation as simultaneously a promising engine of renovation and a threat to both local and national traditions. Salvador carnival's progressive implications of participation and inclusion have been blunted by a process of political redemocratization that was associated with neoliberal policies at the national and local levels; its internal contradictions and commercialism have challenged both its national and local symbolic power

Modes of Esports Engagement in Overwatch

This Open Access book provides a comprehensive review of the rapidly developing esport phenomenon by examining one of its contemporary flagship titles, Overwatch (Blizzard Entertainment 2016), through three central themes and from a rich variety of research methods and perspectives. As a game with more than 40 million individual players, an annual international World Cup, and a franchised professional league with teams from Canada, China, Europe, South Korea, and the US, Overwatch provides a multifaceted perspective to the cultural, social, and economic topics associated with the development of esports, which has begun to attract attention from both commercial and academic audiences. The book starts with an introduction chapter to Overwatch and esports engagement in general, co-authored by the editors. This is followed by 15 unique chapters from scholars within the field of game cultures and esports, representing ten different nationalities. The contributions construct thematic sections that divide the book into three parts: Players, Diverse Audiences? and Fan & Fiction Work. As such, the parts provide a wide-ranging overview of esport engagement, thus disclosing the phenomenon’s cross-cultural, transmedial, and interconnected relations that have not been probed earlier in a single anthology

Aspectos motivacionais no design de tecnologia para mudanças sociais

Orientador: Maria Cecília Calani BaranauskasTese (doutorado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Conectando pessoas e presente em todos os aspectos da vida, quando projetadas para este fim, as tecnologias têm potencial de influenciar a forma com que pessoas em um grupo social percebem e se relacionam com as coisas no ambiente. Este estudo de doutorado em Interação Humano-Computador (IHC) investiga como elementos motivacionais da Psicologia podem ser aplicados para informar o design, explo- rando esse potencial da tecnologia em promover mudanças sociais. O estudo é instanciado no domínio de consumo de energia elétrica, lidando com o desafio contemporâneo de cons- cientizar a sociedade dos limites naturais do planeta no que diz respeito ao uso de recursos naturais. Informar o design com aspectos motivacionais é uma abordagem recente em IHC. Quando encontrada na literatura, comumente tem foco em aspectos individuais e intrín- secos da motivação. Contudo, como argumentado nessa pesquisa, o contexto sociocultural evidencia a importância de considerar também os fatores externos que motivam as pessoas a se engajarem com uma tecnologia e com uma determinada questão social. Por considerar tanto fontes intrínsecas quanto extrínsecas de motivação, a Teoria da Autodeterminação é então considerada o principal referencial teórico da Psicologia nessa investigação, e a Semiótica Organizacional é a base metodológica para analisar os elemen- tos socioculturais que influenciam a motivação extrínseca. A análise situada dos dados socioculturais por uma perspectiva motivacional levou ao design da Tecnologia Socialmente Informada para Eco-Feedback de Energia (sigla SEET, em inglês), uma arquitetura que tem por objetivo estabelecer um novo padrão de com- portamento, ou uma nova maneira de perceber o consumo de energia coletivamente. O SEET é composto por um sistema interativo que promove colaboração, e pela Árvore da Energia, um dispositivo de feedback tangível para locais onde há encontro de pessoas. O SEET é avaliado em dois cenários complementares: uma Escola de Ensino Funda- mental no Brasil, onde os dados socioculturais foram coletados, analisados e aplicados para informar o design; e no contexto de um departamento de uma universidade no Reino Unido. Aspectos motivacionais da arquitetura do SEET são então analisadas, assim como o impacto dessa tecnologia ao desencadear as esperadas mudanças sociaisAbstract: By connecting people and being present in almost all aspects of life, when properly de- signed for that, technology can potentially influence the way people in a social group perceive and relate with things in their environment. This PhD study in the Human-Computer Interaction (HCI) field investigates how motivational elements from Psychology can be applied to inform the design aiming at exploring this potential of technology for promoting a social change. The study is in- stantiated in the energy consumption domain, coping with the contemporary challenge of raising awareness among the society of the planet¿s natural resources usage and limits. Informing the design with motivational aspects is a recent approach in HCI. When found in literature, it is mostly focused on individual and intrinsic aspects of motivation. However, as argued in this research, the sociocultural context evidences the importance of considering also the external factors that motivate people to be engaged with technology and the social issue. By taking into account both intrinsic and extrinsic sources of motivation, the Self- Determination Theory is then considered the main theoretical background from Psychol- ogy in this investigation, and the Organisational Semiotics the methodological basis to analyse sociocultural elements that influence extrinsic motivation. The situated analysis of sociocultural data with motivational lenses has led to the de- sign of a Socially-informed Energy Eco-feedback Technology (SEET), an architecture that aims at establishing a "new pattern of behaviour", or a new way of perceiving collective energy consumption. The SEET is composed by an interactive system that promotes collaboration and The Energy Tree, a tangible and public feedback device for gathering places. The SEET is evaluated in two complementary scenarios: an elementary school in Brazil, where the sociocultural data was collected, analysed and applied to inform design; and in the context of an university department in the United Kingdom. Motivational as- pects of the SEET architecture are then analysed, as well as the impact of this technology to trigger the desired social changeDoutoradoCiência da ComputaçãoDoutora em Ciência da Computaçã

Anime Streaming Platform Wars: A Platform Lab Report

This Lab Report tackles streaming platforms from the angle of anime, one of the prime contents used to gather viewers and subscribers, and their dollars and data. Focused on the circulation of anime on transnational platforms, this Report addresses the rush, over the past decade, for streaming platforms to invest in anime and its audience, up to the point where anime has become a necessary market to take into account when discussing the global streaming ecology

Primary User Emulation Detection in Cognitive Radio Networks

Cognitive radios (CRs) have been proposed as a promising solution for improving spectrum utilization via opportunistic spectrum sharing. In a CR network environment, primary (licensed) users have priority over secondary (unlicensed) users when accessing the wireless channel. Thus, if a malicious secondary user exploits this spectrum access etiquette by mimicking the spectral characteristics of a primary user, it can gain priority access to a wireless channel over other secondary users. This scenario is referred to in the literature as primary user emulation (PUE). This dissertation first covers three approaches for detecting primary user emulation attacks in cognitive radio networks, which can be classified in two categories. The first category is based on cyclostationary features, which employs a cyclostationary calculation to represent the modulation features of the user signals. The calculation results are then fed into an artificial neural network for classification. The second category is based on video processing method of action recognition in frequency domain, which includes two approaches. Both of them analyze the FFT sequences of wireless transmissions operating across a cognitive radio network environment, as well as classify their actions in the frequency domain. The first approach employs a covariance descriptor of motion-related features in the frequency domain, which is then fed into an artificial neural network for classification. The second approach is built upon the first approach, but employs a relational database system to record the motion-related feature vectors of primary users on this frequency band. When a certain transmission does not have a match record in the database, a covariance descriptor will be calculated and fed into an artificial neural network for classification. This dissertation is completed by a novel PUE detection approach which employs a distributed sensor network, where each sensor node works as an independent PUE detector. The emphasis of this work is how these nodes collaborate to obtain the final detection results for the whole network. All these proposed approaches have been validated via computer simulations as well as by experimental hardware implementations using the Universal Software Radio Peripheral (USRP) software-defined radio (SDR) platform