På avdelningen Medicinsk Teknik-Forskning och Utveckling på Norrlands Universitetssjukhus (MT-FoU) pågår en utveckling av ett rörelsemätsystem (MoLab) som syftar till att ge kvantitativa data från individer med nedsatt rörelsefunktion. Denna information kan fungera som underlag för behandling och användas för att utvärdera uppföljning av behandlingar. Mätsystemet begränsas idag av att det är beroende av en accesspunkt med tillhörande lokalt nätverk för att föra över data till insamlingsdator via TCP/IP-protokollet.   Examensarbetet syftar till att öka mätsystemets mobilitet genom att inkludera en portabel och trådlös mätlösning utan krav på stationär accesspunkt och insamlingsdator vid insamlingstillfället. Med ett mer mobilt mätsystem kan data inhämtas från individer i dennes autentiska och vardagliga miljö.   En lokal lagringsyta har kopplats till sensorenheterna och användargränssnittet utgörs istället av en fjärrkontroll, som startar och stoppar mätningar. Fjärrkontrollen fungerar också som en accesspunkt som sensorenheterna ansluter till och som vidarebefordrar start- och stoppsignaler via UDP-broadcast från fjärrkontroll till alla uppkopplade sensorenheter. Vid given stoppsignal överförs sensordata till fjärrkontrollen för efterföljande lagring på dess interna minneskort. Det är viktigt att mätningarna sker synkront mellan sensorenheterna, där startsynkroniseringen kan kvantifieras som tidsdifferensen mellan sensorenheternas mätstart.  Med metoden som föreslås i detta arbete, hamnar startsynkroniseringen väl under ett väldefinierat tröskelvärde på 2 ms som också fanns implementerat i MoLab och är därför en tänkbar metod för att utöka mobiliteten för MoLab. / The department of Biomedical Engineering Research and Development at University Hospital (MT-FoU) is developing a motion measurement system (MoLab) that aims to provide quantitative data from individuals with impaired mobility. This information can serve as a basis for treatments and used to evaluate follow-up of treatments. The measuring system is today limited by the fact that it is dependent on an access point and associated local network to communicate data to an evaluation computer via the TCP/IP protocol. This is a bachelor thesis that aims to give this measuring system greater freedom to measure without dependence of a stationary access point and evaluation computer. With a more mobile system, data can be obtained in a more authentic and everyday environment for the individuals to be measured.  An internal memory has been connected to the inertial sensor devices, and the user interface is instead a remote control, which starts and stops measurements. The remote-control acts as the access point which the sensor devices connects to and start and stop signals are transmitted via UDP broadcast from the remote-control to the sensor devices. In case of a given stop signal, sensor data is transferred to the internal memory of the remote control. It is important that the measurements take place synchronously where the synchronization can be quantified as the time difference between the sensor devices at the measurement start. With this method, start synchronization ends up well below a well-defined threshold value of 2 ms that was also implemented in MoLab, giving it greater mobility.

Made available in DSpace on 2016-04-04T18:31:19Z (GMT). No. of bitstreams: 1 CARLOS SALDANHA.pdf: 2117803 bytes, checksum: 2021a031c03613d9b6c2df0e8e8aba68 (MD5) Previous issue date: 2007-06-28 / Digital Inclusion is currently a concerning subject especially in those urgent countries. In Brazil there have been various initiatives and experiences regarding this subject, both from government parts (Federal, State and Urban) and through Non-Profitable Organizations and private companies. The approach to low-cost Broadband Internet has been one of the main barriers to the effectiveness on these initiatives. The goal of this current work is to find new concepts and connection management and voice services, data and video (triple play) in a unique wireless connection focusing on digital inclusion. The used wireless technology is the World Interoperability for Microwave Access (WiMAX), whose frequency is of 5,8 GHZ, which permission is not required for its usage along with National Telecommunication Agency (ANATEL) and to the access point, the wireless fidelity technology (Wifi). Some main convergent WiMAX technology characteristics are described in this work with new Triple Play services to hold a multipoint-point enlacement, causing an establishment to link a case study between the School and PUC-Campinas in order to investigate the performance and application factors. The results on the efficiency of metropolitan wireless network (WMAN) as well as the Triple Play services were profitable, defining a new method on prediction of coverage area and user s quantity. / Inclus?o Digital ? hoje um tema de muita preocupa??o, principalmente nos pa?ses denominados emergentes. No Brasil existem diversas iniciativas e experi?ncias relativas a esse assunto, tanto por parte dos governos (Federal, Estadual e Municipal), como tamb?m por parte de ONG s e empresas privadas. O acesso ? Internet Banda Larga a baixo custo tem sido uma das principais barreiras para a efetiva??o dessas iniciativas. O prop?sito do presente trabalho ? definir novos conceitos e par?metros de conex?o e servi?os de voz, dados e v?deo (triple play) em uma ?nica conex?o sem fio com foco na inclus?o digital. A tecnologia de conex?o sem fio (wireless) utilizada ? o World Interoperability for Microwave Acess (WiMAX), de freq??ncia 5.8 GHz, que n?o requer licenciamento para a sua utiliza??o junto a Ag?ncia Nacional de Telecomunica??es (ANATEL) e para o ponto de acesso, a tecnologia wireless fidelity (WiFi). Neste trabalho est?o descritas as principais caracter?sticas da tecnologia WiMAX convergentes, com os novos servi?os Triple Play para a realiza??o de um enlace ponto-multiponto, estabelecendo-se um link para estudo de caso entre a Escola e a PUC-Campinas, para a investiga??o dos fatores de desempenho e aplica??es. Os resultados de efici?ncia da rede sem fio metropolitana (WMAN) com os servi?os Triple Play foram satisfat?rios, definindo-se um novo m?todo de predi??o da ?rea de cobertura e do n?mero de usu?rios.

Made available in DSpace on 2016-04-04T18:31:30Z (GMT). No. of bitstreams: 1 Luis Fernando Fontolan.pdf: 1957918 bytes, checksum: c54c21cddbc7cc91dd162510efebc7c4 (MD5) Previous issue date: 2010-02-26 / The IEEE802.11 standard assumes that the stations (STAs) of a communications network have the same condictions during medium access, through the usage of the DCF (Distributed Coodination Function). The DCF states that all stations have the same probability of medium access, regardless of transmission rates or signal to noise ratios. Furthermore, such networks also presents an anomaly by which it is possible that a station with low transmission rate may request the channel for an extended period of time. In this context, this work proposes a QoS policy-based implementation based on the 802.11e standard, which aims to maintain a scenario of greater justice in IEEE802.11 networks. In doing so, it is proposed an algorithm to determine a Justice Index associated to a specific network, by examining the STAs connection rate, their type of service and the requirements for customer service. Thus, stations are served at rates that consider the physical characteristics of the network, in order to optimize their resources, from the viewpoint of the service provider. Results were obtained on simulated networks using the NS2 software considering the proposed policy of justice and show that the analyzed scenarios yield network troughput gain or at least result in a condition similar to that obtained without the use of the proposed justice policy. / O padr?o IEEE802.11 foi especificado presumindo condi??es de igualdade em rela??o ao acesso ao meio por parte das STAs de uma rede, pelo emprego do m?todo DCF , onde todas as STAs possuem a mesma probabilidade de acesso ao meio, sem levar em considera??o sua taxa de transmiss?o ou sua rela??o sinal-ru?do. No entanto, ? necess?rio ressaltar que tais redes apresentam uma anomalia, atrav?s da qual ? poss?vel que uma STA com baixa taxa de transmiss?o venha a ocupar o canal por um grande per?odo de tempo. Nesse contexto, esse trabalho apresenta uma proposta de pol?tica de QoS baseada na implementa??o do padr?o 802.11e, que objetiva manter um cen?rio de maior justi?a em redes IEEE802.11. Para isso ? proposto um algoritmo de c?lculo de ?ndice de justi?a atrav?s da an?lise da taxa de conex?o, do tipo de servi?o e dos requisitos necess?rios para atendimento do servi?o. Assim, as STAs s?o servidas a taxas que levam em conta as caracter?sticas f?sicas da rede, de forma a otimizar os seus recursos, do ponto de vista do provedor. Resultados obtidos com a pol?tica proposta em redes simuladas atrav?s do software NS2 demonstram que os cen?rios analisados resultaram em um ganho em rela??o ao troughput da rede ou, no m?nimo, em uma condi??o semelhante ? obtida sem a utiliza??o da pol?tica.

A interferência espectral gera patologias nos sistemas de comunicação sem fio (wireless), como por exemplo, quedas na comunicação e degradação na vazão. O espectro de RF (rádio frequência) é fiscalizado e controlado por órgãos governamentais, no entanto as redes sem fio padrão IEEE 802.11, conhecidas por WLANs (Wireless Local Area Networks), trabalham em faixas espectrais não licenciadas, conhecidas por ISM. Estas redes estão cada vez mais presentes nos ambientes comerciais e residenciais, contribuindo para questões de ubiquidade e acesso à Internet. Com este aumento expressivo, a cobertura espectral está cada vez mais densa. A densidade elevada de sinais aponta para a saturação do espectro ISM, causando interferências mútuas das redes IEEE 802.11. O objetivo deste trabalho é analisar a cobertura do espectro, por redes WLANs, e avaliar quedas de vazão ocasionadas por interferências espectrais, variando no espaço e no tempo. Dois cenários foram mapeados para analisar as degradações, um com baixa a média e outro com alta densidade e complexidade. O objetivo da criação desses cenários foi comparar as degradações causadas pelas interferências em ambientes diferentes, na ocupação, na utilização e na propagação de sinais de redes WLANs. Através dos resultados obtidos, um ciclo de vida de gerenciamento do espectro de redes padrão 802.11 foi proposto. Este ciclo contribui para avaliar e classificar o estado de uma rede em densa, não densa, complexa e não complexa, visto que alterações de ocupação do espectro no espaço e no tempo são plausíveis de ocorrerem. Conclui-se que os impactos da sobreposição total do canal, por fontes 802.11, não são suficientes para a substancial degradação da vazão em ambientes de baixa a média complexidade. Em ambientes com alta densidade e complexidade as degradações são mais evidentes, principalmente quando ocorrem perturbações vindas de duas fontes adjacentes / The spectral interference generates pathologies in wireless communication systems (wireless), such as declines in communication and degradation in flow. The spectrum of RF (radio frequency) is supervised and controlled by government agencies, however the wireless standard IEEE 802.11, known as WLANs (Wireless Local Area Networks), work in unlicensed spectrum bands, known as ISM. These networks are increasingly involved in commercial and residential environments, contributing to issues and ubiquity of Internet access. With the significant increase in these networks, the spectral coverage is increasingly dense. The high density of signals pointing to the saturation of the ISM spectrum, causing mutual interference of IEEE 802.11 networks. The aim of this study is to analyze the coverage of the spectrum, for WLANs, and evaluate the flow falls caused by spectral interferences, varying in space and time. Two scenarios were mapped to examine the degradations, with a low to medium and one with high density and complexity. The purpose of creating these scenarios was to compare the degradation caused by interference in different environments, occupation, use and spread of signals WLANs. Through the results, a life cycle management of the spectrum of standard 802.11 networks was proposed. This cycle helps to evaluate and classify the state of a dense network, not dense, complex and not complex, since changes in occupation of the spectrum - in space and time - are plausible to occur. It is concluded that the impacts of the complete overlap of the channel, sources 802.11, are not sufficient to the substantial degradation of the flow in low to medium complexity. In environments with high density and complexity of the degradation is more evident, especially when there are disturbances coming from two adjacent sources

L’ensemble des travaux présentés au sein de manuscrit porte sur la réalisation d’un synthétiseur de fréquences millimétriques capable de répondre aux besoins de la convergence WiFi-WiGig. Une première étude est réalisée dans le but de définir une architecture de synthétiseur de fréquence faible consommation adaptée aux standards du WiFi et du WiGig. L’ensemble des éléments composants la PLL sont par la suite détaillés, mettant en avant les avantages offerts par la technologie 28 nm FDSOI CMOS. Une étude plus approfondie des VCO millimétriques large bande et faible consommation est ensuite présentée, permettant de mettre en avant une réelle méthodologie de conception en lien avec la technologie 28 nm FDSOI CMOS. Finale-ment, diverses solutions sont proposées dans le but d’améliorer les performances de la PLL, avec l’incorporation de VCO millimétriques à ondes lentes, ou d’oscillateurs à anneaux synchronisés. / The works presented in this manuscript focus on the realization of a millimeter frequency synthesizer meeting the needs of the WiGig-Fi convergence. A first study was conducted to define a suitable low-power frequency synthesizer archi-tecture for WiFi and WiGig standards. All of the PLL components are subsequently detailed, highlighting the 28nm CMOS FDSOI technology benefits. Then, a study of low power millimeter broadband VCO is presented, highlighting a design methodology related to the 28nm CMOS FDSOI technology. Finally, various solutions are proposed in order to improve the PLL performances, with the incorporation of slow wave VCO, or injection locked ring oscillators.

近來幾年智慧型手機和適地性服務已經變得非常熱門。 智慧型手機必須有辦法知道使用者的位置，因此精準的定位技術就變得重要。 至今人們只能夠在特定的環境利用某些定位方法，就像是GPS只能用於室外的空間。 但是人們總是生活於大範圍的環境像是校園、都市和觀光區，這種大範圍的環境包含了室內和室外的空間。 大範圍的環境下，單一定位技術未必到處都可用，因此我們結合了GPS、WiFi和物聯網定位提出了一個異質式定位演算法。 我們提出“定位可能性”來選擇比較“可靠”(可能)的定位方法。 除此之外，利用較可靠的鄰近使用者與自己之間的WiFi訊號強度可更進一步改善定位的精準度。特別針對某些使用者在沒有任何可用的定位方法時更有幫助。這個方法被稱為“合作式定位”。 最後，我們用模擬來評估我們演算法的精準度。 因為訊號強度每分每秒都在波動，因此我們測量實際的訊號強度和GPS放入模擬器，讓實驗結果變得更真實。 最後我們也證明我們的演算法可以做在手機上而且更精準。 / Smart phones and Location Based Services (LBSs) have become very popular in recent years. To this end, the smart phone needs to know the locations of users. Therefore, an accurate localization technique is important. To date people can use some localization systems in some specific areas. For instance, GPS can only be used in the outdoor space. However, people always live in large scale environments like campus, urban and tourist areas. The large scale environments should include indoor and outdoor space. For large scale environment, a single location technique is not always available everywhere. Therefore, we proposed a heterogeneous localization algorithm which combines GPS, WiFi and Internet Of Things (IOT) localizations. We proposed “localization possibility” for each localization methods. This algorithm use localization possibility to select the most “reliable” (possible) one. Besides, the more reliable nearby users can further enhance the localization by measuring the relative WiFi signal strength. It helps especially for those users who have no any available localization methods. This method is called “cooperative localization”. Finally, we evaluated the accuracy of our algorithms by simulation. Because signal strength fluctuates from minute to minute, we measured empirical data and put into the simulator to make our experimental results more real. Finally, we also verify that our idea can be implemented on smart phones and our algorithm is more accurate.

This thesis is a techno-economic study focus on the IoT connectivity service field. It describes the specifications of LPWAN, LPLAN, and Cellular-IoT technologies. The analysis method of dimensioning and cost structure calculation of IoT network is enhanced from previous wireless network research, which is also a research gap in the telecom industry. By using this method, the dimensioning results and cost structure performances can be obtained when having the inputs of the scenario. The results are compared among SigFox, LoRaWAN, NB-IoT, LTE-M, EC-GSM-IoT, and WiFi-HaLow. Furthermore, we find out the cost driver of different technologies. When it comes to different actors, a new market entrant or an incumbent, the strategies taken by the actors are compared. They are building own sites or leasing sites from other actors, even reusing sites if possible. The contribution of this thesis is pointing out the dimensioning and cost structure calculation method of deploying IoT connectivity. Another contribution is comparing the cost performance and figuring out the cost driver. SigFox is costefficient for low capacity scenario, while LTE-M is of good cost performance for high capacity cases. The cost driver is operation and maintenance cost and site build cost. By leasing and reusing sites, the site build cost can be largely reduced. / Denna avhandling har ett ekonomiskt och tekniskt perspektiv på anslutningstjänsten IoT. Den beskriver specifikationerna för LPWAN, LPLAN och Cellular-IoT teknik. Analysmetoden för dimensionering och beräkning av kostnadsstruktur av IoT-nätet har förbättrats jämfört med tidigare trådlös nätverksforskning, vilket i sig är ett område som saknar tillräcklig forskning inom telekombranschen. Genom att använda den här metoden kan dimensioneringens resultat och prestandan av kostnadsstrukturen erhållas när indata finns tillgängligt för olika fall/scenarion. Resultaten jämförs bland SigFox, LoRaWAN, NB-IoT, LTE-M, EC-GSM-IoT och WiFi-HaLow. Dessutom hittar vi kostnadsdrivaren av olika teknologier. När det gäller olika aktörer, en ny marknadsaktör eller en etablerad aktör, jämförs de olika strategier som aktörerna använder. De bygger egna basstationer eller leasar basstationer från andra aktörer, och i vissa fall även återanvändning av basstationer om så är möjligt. Denna avhandling bidrar till att peka ut beräkningsmetoden för dimensioneringen och kostnadsstruktur av att bygga ut IoT-anslutningar. En annan slutsats är jämförelsen av kostnadseffektiviteten mellan olika teknologier och att komma underfund med kostnadsdrivaren. SigFox är kostnadseffektiv i fallen där kapaciteten är låg, medan LTE-M har bra kostnadseffektivitet i fallen där kapaciteten är hög. Kostnadsdrivaren är driftoch underhållskostnad samt kostnad för konstruktionen av byggplatsen. Genom att leasa och återanvända basstationer kan kostanden för konstruktionen av byggplatsen minskas till en stor del.

Avec l’apparition des nouvelles technologies de communication, le nombre des systèmes embarqués avionique et automobile est en constante augmentation. La gestion des communications entre ces systèmes devient alors de plus en plus complexe à mettre en oeuvre dans un contexte où les contraintes temporelles et environnementales sont très fortes et où le taux d’échanges de messages en augmentation continuelle. L’utilisation optimale des réseaux pour acheminer les données tout en respectant les contraintes temporelles imposées est essentielle du point de vue de la sûreté de fonctionnement. Historiquement, pour répondre aux problématiques d’efficacité et de sûreté, les industriels ont développé une palette de réseaux embarqués dédiés à leurs applications cibles (CAN, LIN, . . . ). Ces réseaux présentaient des débits relativement faibles à un moment où un besoin croissant en bande passante se faisait ressentir. le choix d’utiliser le concept de composants dit ‘sur étagères’ (off the shelf COTS) permettait alors de pallier à ce nouveau besoin. Dans un souci de conservation des capacités des réseaux à garantir les contraintes temporelles imposées par les systèmes embarqués temps réel, les industriels ont dû adapter ce concept de composants sur étagères aux systèmes embarqués. L’intérêt de l’utilisation de ces composants est un gain non négligeable en bande passante et en poids pour des coûts de développements relativement faibles. L’introduction de ces composants nouveaux s’est faite de telle sorte que leur impact sur les standards préexistants et les systèmes connectés soit minimal. C’est ainsi que les réseaux dit ‘hétérogènes’ ont vu leur apparition. Ces réseaux constituent une hybridation entre les technologies embarquées historiques et les composants sur étagère. Ils consistent en des réseaux d’extrémité utilisant des technologies éprouvées (telles que le CAN) interconnectés via des passerelles à un réseau fédérateur (backbone) utilisant des composants sur étagères. Dès lors, le défi majeur à relever lors de l’utilisation d’un réseau fédérateur est de respecter les contraintes temporelles des applications sollicitant les différents réseaux. L’objectif est mis à mal sur les points d’interconnexion des réseaux hétérogènes (Passerelles). Ainsi l’approche principale utilisée pour le passage d’un réseau à un autre est l’encapsulation de trames. Pour atteindre l’optimalité de performance de cette technique plusieurs paramètres sont à prendre en compte tels que le nombre de trames à encapsuler, les ordonnancements utilisés, le coût en bande passante ainsi que l’impact sur les distributions de délais (gigue). Dans l’optique de préservation des performances des réseaux, l’objet de nos travaux porte sur l’étude, la comparaison et la proposition de techniques permettant l’interconnexion de réseaux hétérogènes temps réels à la fois pour des applications à faibles et à fortes contraintes temporelles. Après un état de l’art sur les réseaux temps réel, nous spécifions différentes techniques d’interconnexion de réseaux hétérogènes, puis, nous présentons une étude de cas basée sur une architecture réseau interconnectant différents bus CAN via un réseau fédérateur sans fil Wi-Fi. L’étude que nous avons menée montre, par le biais de différentes simulations, que cette architecture réseau est une bonne candidate pour la transmission de flux à contraintes temporelles faibles. Une architecture réseau interconnectant différents bus CAN via un réseau fédérateur Ethernet commuté est ensuite considérée dans une seconde étude de cas ciblant les applications à fortes contraintes temporelles. Dans un premier temps, nous prenons en compte le cas d’un réseau fédérateur Ethernet-PQSE et, dans un second temps, le cas d’Ethernet-AVB. Cette étude nous permet de montrer l’impact des différentes techniques d’interconnexion sur les délais des flux du réseau. / With the emergence of new communication technologies, the number of avionics and automotive embedded systems is constantly increasing. The management of communications between these systems becomes increasingly complex to implement in a context where temporal and environmental constraints are very strong and where messages exchange rate is continuously increasing. The optimal use of networks to transmit data while fulfilling the imposed temporal constraints is essential from a safety point of view. Historically, in order to address safety and efficiency issues, manufacturers have developed a range of embedded networks dedicated to their target applications (CAN, LIN, . . . ). These networks have relatively low bit rates at a point of time where a growing need for bandwidth was felt. To overcome this new need, the choice of using the concept of so-called ’off-theshelf’ components (COTS) has been made. In order to preserve the networks abilities to guarantee the temporal constraints imposed by the real time embedded systems, manufacturers had to adapt the concept of off-the-shelf components to embedded systems. The benefits of using these components is a non-negligible gain in bandwidth and weight for relatively low development costs. The introduction of these new components has been made in such a way that their impact on pre-existing standards and connected systems is minimal. thereby, so-called ’heterogeneous’ networks have emerged. These networks are a hybridization of historical embedded technologies and off-the-shelf components. They consist of stub networks using proven technologies (such as CAN) interconnected via gateways to a backbone network using off-the-shelf components. Thus, the major challenge while using a heterogeneous network is to respect the temporal constraints of the applications requesting the different parts of the networks. This objective can be damaged at the interconnection points of the heterogeneous networks (Gateways). The main used approach to pass frames from one network to another is the encapsulation. To achieve the optimum performances of this technique, several parameters have to be considered such as the number of frames encapsulated, the used scheduling policy, the bandwidth cost as well as the impact on delay distributions (jitter). In order to preserve networks performances, the aim of our work is to study, compare and propose techniques ennabling the interconnection of real-time heterogeneous networks for application with both soft and hard temporal constraints. After a state of the art on real-time networks, we have specified different techniques for the interconnection of heterogeneous networks, then we have presented a case study based on a network architecture interconnecting different CAN buses via a wireless backbone network (Wi-Fi ). The study we conducted shows, through various simulations, that this network architecture is a good contender for the transmission of flows with soft temporal constraints. A network architecture interconnecting different CAN busses via a switched Ethernet backbone is considered in a second case study targeting applications with hard temporal constraints. Two different Ethernet backbone networks are taken into account. We studied first, the case of a switched Ethernet-PQSE backbone network. Then the case of a switched Ethernet-AVB backbone is considered. This study enabled us to highlight the impact of the different used interconnection techniques on network flows delays.

Orientador: Prof. Dr. Carlos Alberto Kamienski / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia da Informação, 2016. / Atualmente é comum as pessoas se conectarem à Internet em lugares públicos como praças, parques e bibliotecas. Algumas cidades oferecem conexão gratuita por WiFi, onde os usuários utilizam a Internet para diversas finalidades, como buscar informações, trocar mensagens e assistir a mídias digitais. A abordagem deste trabalho é a utilização de streaming de vídeo em praças digitais distribuídas pelas diversas regiões da cidade de São Paulo. Foram realizadas análises de desempenho do serviço prestado à comunidade nas cento e vinte praças do programa "WiFi Livre SP", no período de um ano. Para isso, foram utilizadas métricas que avaliam tanto a Qualidade de Experiência (QoE) do usuário, como a Qualidade de Serviço (QoS) da rede. Como resultado, obteve-se uma nova ferramenta de avaliação da Qualidade de Experiência dos usuários em transmissões de streaming de vídeo, bem como as características das praças em relação aos dados analisados, os quais mostram que, para diferentes praças, dias e níveis de qualidade de vídeo, na maioria das vezes, o uso é satisfatório para determinados fins. / Currently it is common for people to connect to the Internet in public places such as squares, parks and libraries. Some cities offer free connection by WiFi, where users use the Internet for various purposes, such as searching for information, exchange messages and watch digital media. The approach of this work is the use of video streaming in digital squares distributed among different regions of São Paulo. Performance tests of this service to the community were carried out in the 120 squares belonging to the "WiFi Livre SP program" in one year. For this we used metrics that assess both the Quality of Experience (QoE) of the user, such as Quality of Service (QoS) network. As a result we obtained a new evaluation tool of Quality of Experience of users in streaming videos, and the characteristics of the squares on the data analyzed which show that for different places, days and levels of video quality, in most of the time the use is satisfactory for particular purposes.

A interferência espectral gera patologias nos sistemas de comunicação sem fio (wireless), como por exemplo, quedas na comunicação e degradação na vazão. O espectro de RF (rádio frequência) é fiscalizado e controlado por órgãos governamentais, no entanto as redes sem fio padrão IEEE 802.11, conhecidas por WLANs (Wireless Local Area Networks), trabalham em faixas espectrais não licenciadas, conhecidas por ISM. Estas redes estão cada vez mais presentes nos ambientes comerciais e residenciais, contribuindo para questões de ubiquidade e acesso à Internet. Com este aumento expressivo, a cobertura espectral está cada vez mais densa. A densidade elevada de sinais aponta para a saturação do espectro ISM, causando interferências mútuas das redes IEEE 802.11. O objetivo deste trabalho é analisar a cobertura do espectro, por redes WLANs, e avaliar quedas de vazão ocasionadas por interferências espectrais, variando no espaço e no tempo. Dois cenários foram mapeados para analisar as degradações, um com baixa a média e outro com alta densidade e complexidade. O objetivo da criação desses cenários foi comparar as degradações causadas pelas interferências em ambientes diferentes, na ocupação, na utilização e na propagação de sinais de redes WLANs. Através dos resultados obtidos, um ciclo de vida de gerenciamento do espectro de redes padrão 802.11 foi proposto. Este ciclo contribui para avaliar e classificar o estado de uma rede em densa, não densa, complexa e não complexa, visto que alterações de ocupação do espectro no espaço e no tempo são plausíveis de ocorrerem. Conclui-se que os impactos da sobreposição total do canal, por fontes 802.11, não são suficientes para a substancial degradação da vazão em ambientes de baixa a média complexidade. Em ambientes com alta densidade e complexidade as degradações são mais evidentes, principalmente quando ocorrem perturbações vindas de duas fontes adjacentes / The spectral interference generates pathologies in wireless communication systems (wireless), such as declines in communication and degradation in flow. The spectrum of RF (radio frequency) is supervised and controlled by government agencies, however the wireless standard IEEE 802.11, known as WLANs (Wireless Local Area Networks), work in unlicensed spectrum bands, known as ISM. These networks are increasingly involved in commercial and residential environments, contributing to issues and ubiquity of Internet access. With the significant increase in these networks, the spectral coverage is increasingly dense. The high density of signals pointing to the saturation of the ISM spectrum, causing mutual interference of IEEE 802.11 networks. The aim of this study is to analyze the coverage of the spectrum, for WLANs, and evaluate the flow falls caused by spectral interferences, varying in space and time. Two scenarios were mapped to examine the degradations, with a low to medium and one with high density and complexity. The purpose of creating these scenarios was to compare the degradation caused by interference in different environments, occupation, use and spread of signals WLANs. Through the results, a life cycle management of the spectrum of standard 802.11 networks was proposed. This cycle helps to evaluate and classify the state of a dense network, not dense, complex and not complex, since changes in occupation of the spectrum - in space and time - are plausible to occur. It is concluded that the impacts of the complete overlap of the channel, sources 802.11, are not sufficient to the substantial degradation of the flow in low to medium complexity. In environments with high density and complexity of the degradation is more evident, especially when there are disturbances coming from two adjacent sources