This thesis addresses the problem of building a Cognitive Radio that has the ability to interact with human users in a better way by making use of Quality of Experience (QoE) as its basis and marshalling its resources optimally around the user. Salient activities of this thesis include: Analysis of CR leads to the definition of its basic functional blocks such as cognition, learning and adaptation of radio behaviour in a multi-disciplinary manner. CR tracts signal processing for radio and sensors, cognitive and behavioural psychology for user intelligence, machine learning and AI for decision systems and optimization etc. Therefore it provides a rich, fertile area to make lateral connections across diverse helds. This thesis proposes a broad definition for CR (called as Unifed Cognitive Radio) inspired by key foundation works described in literature. Besides, it also describes its functionality and its ecosystem. Taking cue from the definition of UCR, this thesis proposes architectural frame-works for various sub-systems. Also their design and implementation is achieved with the aid of a comprehensive tested setup and is tested using realistic scenarios. Builds a set of intelligent decision systems that help to achieve the set goal. This involves various design decisions with a set of diverse algorithms from the world of signal processing, machine learning and articial intelligence. Transitioning disparate small functional entities (mostly built around experiments) into an integrated system that works in real-world environment is the key aspect of this thesis. It is definitely a challenging task. Therefore, starting from deterring the architectural reference frameworks for realizing various sub-systems of UCR to an evaluation based on integrated scenario, this being an important final step constitutes a sign cant amount of work. Analysis and implementation of the integrated system to meet the desired end functionality - QoE centricity of the CR system to satisfy the needs of the end user better is the contribution of this thesis

A streaming video has features that differs from other streams: the occupation of large amount of bandwidth, and the possible variation of scenes with consequent increase (or decrease) in amount of bytes transmitted. Applications for video streaming transmission (YouTube, Vimeo, Netflix, Telecine Play, etc.) have aroused the interest of the scientific community regarding the behavior of networks. Our proposal is to measure, from a video stream, the user experience (QoE) based on arbitration QoS parameters in a controlled environment which use NetFPGA. The results of the experiments has shown the efficacy of TCP over UDP, which at the stage of choosing the most appropriate protocol for testing, showed to be ineffective to the Gigabit Ethernet rate. These experiments occurred in distinct physical topologies; only Cisco routers, with and without QoS, with and without injection of traffic generated by software iperf in the network, and using NetFPGA board set to router only with and without traffic via iperf, once the design developed to make the board work as a router does not allow QoS settings. in these scenarios, there was the need to start the client running at different times, setting their respective caches different networks so that did not coincide scenes, avoiding high bandwidth peaks in stretches with a lot of movement. / Um streaming de vídeo tem características que o difere dos demais fluxos: a ocupação de grande quantidade de banda, e a possíveis variações de cenas com consequente aumento (ou diminuição) na quantidade dos bytes transmitidos. Aplicações para transmissão de streaming de vídeo (YouTube, Vimeo, NetFlix, Telecine Play, e etc.) tem despertado o interesse da comunidade científica quanto ao comportamento das redes. Nossa proposta é correlacionar, a partir de um fluxo de vídeo, a experiência do usuário com base na arbitragem de parâmetros de QoS em ambiente controlado. O resultado dos experimentos demonstrou a eficácia do protocolo TCP sobre o UDP, que na fase da escolha do protocolo mais adequado para os testes, mostrou-se ineficiente até a taxa Gigabit Ethernet. Esses experimentos ocorreram em topologias físicas distintas; apenas com roteadores Cisco, com e sem QoS, tendo ou não injeção de tráfego gerado pelo software iPerf na rede, e usando a placa NetFPGA no modo router, apenas com e sem tráfego via iPerf, uma vez que o projeto desenvolvido para fazer a placa atuar como roteador não permite configurações de QoS. Nesses cenários, constatou-se a necessidade de iniciar a execução dos clientes em momentos diferentes, configurando seus respectivos caches de redes diferentes, para que não coincidissem as cenas, evitando altos picos de banda em trechos com muita movimentação.

Submitted by Marta Toyoda (1144061@mackenzie.br) on 2018-02-16T18:40:42Z No. of bitstreams: 2 Vitor Chaves de Oliveira.pdf: 3871136 bytes, checksum: ecb40f1164646a21127f6de607806793 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Paola Damato (repositorio@mackenzie.br) on 2018-02-22T13:39:12Z (GMT) No. of bitstreams: 2 Vitor Chaves de Oliveira.pdf: 3871136 bytes, checksum: ecb40f1164646a21127f6de607806793 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-02-22T13:39:12Z (GMT). No. of bitstreams: 2 Vitor Chaves de Oliveira.pdf: 3871136 bytes, checksum: ecb40f1164646a21127f6de607806793 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-08-11 / In the current IP video scenario, the lack of mechanisms that record two technical parameters that influence the commercial chain that sustains this ecosystem related to the Internet, are: availability and audience. And the expressive growth of this type of transmission, continually rivals it with TV. Thus, with the objective of measuring this new medium of audiovisual offer, this work has developed methodologies to acquire such information at this consumer's point and to compare the viability of transitioning from traditional TV to IP Stream. And, this was accomplished through a technical-mathematical comparison and by the construction of two softwares each with a purpose, with their respective requirements analysis, as well as the method of how to interpret the results and infer how these parameters are related. One was programmed to verify the availability of any IP connections through an application that can be used on any browser platform. And the other, implemented as an extension to one of the most used browsers, Google Chrome, to capture the audience of Internet videos on the leading supplier of videos exists today, Google's YouTube. In this work, the abstractions of considerations around the Quality of Service (QoS) concept, is proposed to be interpreted as a measure of Quality of Experience (QoE) assimilated from the quantities of times and interactions with a video. This justification is founded on the concept that quality translates into a particular subjectivity for each user and their individual expectations, so a measure of time is shown to be an effective valuation. Such effectiveness is justified by a principle consolidated within TV broadcast for decades, audience measurement. That is, building something analogous to the People's meter, similar to the Television Rating Points, TRP, running to capture information that brings assertiveness to all stakeholders in this new delivery method. In this way, we can measure the reliability of the content for the Customer, the Content Producer, the Advertiser, the Platform holder, the Content Delivery Network owner (CDN) and the Internet Service Provider (ISP)). / No atual cenário de vídeo IP se destaca a falta de mecanismos que registrem dois parâmetros técnicos que influenciam a cadeia comercial que sustenta todo este ecossistema relativo à Internet, são eles: disponibilidade e audiência. E o expressivo crescimento deste tipo de transmissão, rivaliza-a continuamente com a TV. Sendo assim, e com o objetivo de metrificar esse novo meio de oferecimento de audiovisual, este trabalho desenvolveu metodologias para adquirir tais informações nesta ponta do consumidor e para comparar a viabilidade da transição de broadcast tradicional de TV por Stream IP. E, isto foi realizado através de um comparativo técnicomatemático e da construção de dois softwares cada qual com uma finalidade, com suas respectivas análises de requisitos, bem como o método de como interpretar os resultados e inferir como estes parâmetros se relacionam. Um foi concebido para aferir a disponibilidade de quaisquer conexões IP sendo uma aplicação passível de ser utilizada em diversas plataformas de navegadores, denominados Browsers. E, o outro, implementado como extensão para um dos Browsers mais utilizados, o Google Chrome, para capturar a audiência de vídeos da Internet no maior fornecedor de vídeos existente hoje, o YouTube do Google. Neste trabalho, a extração de considerações ao redor da Qualidade de Serviço, QoS, é proposta a ser interpretada como medida da Qualidade da Experiência, QoE a partir dos diversos tempos e interações totais de um vídeo. Para tanto, dado que o conceito de qualidade se traduz em uma subjetividade particular de cada usuário e suas expectativas individuais, a medida do tempo se mostra como uma eficaz valoração. Tal eficácia é justificada através do princípio da consolidada medida de audiência da difusão de TV há décadas. Isto é, a construção de algo análogo ao ‘People’s meter’ similarmente ao ‘Television Rating Points’, TRP, executando a captura de informações que tragam assertividade para todas as partes interessadas neste novo método de entrega. Propiciando, desse modo, a aferição com este mesmo nível confiabilidade para o usuário, o produtor de conteúdo, o anunciante, o detentor da plataforma, o proprietário da rede de entrega de conteúdo (CDN) e o provedor de acesso à internet (ISP).

[EN] Broadband Internet access connections allow Internet Service Providers (ISP) to offer several types of services to home customers such as data, voice over IP (VoIP), Internet protocol television (IPTV) and now 3D Internet protocol television (3D- IPTV). That is why the number of IPTV service providers is increasing conside- rably in recent years. Thanks to the evolution at many levels of the communication systems, communication networks and devices, to deliver these services is possible, but the maximum quality is not always guaranteed. For this reason, one of the main issues to be considered by the IPTV service providers is to guarantee the Quality of Experience (QoE) perceived by the end user. In order to achieve this goal, in this PhD Thesis we propose an intelligent management system based on inductive prediction methods to guarantee the QoE of the end-user. One of the important aspects to be considered in the development of the management system is to include all the parameters that affect the QoE. With this purpose, we will analyze the parameters that affect the degradation of the video stream received by the end user through the IPTV service. At the network level, we will identify the main parameters which affect the Quality of Service (QoS), such as jitter, delay, lost packets and bandwidth. At the user level, these parameters affect to the subjective perception of the user when watching the video. We also checked that effects derived from the compression, quantization, and bitrate affect this perception too. / [ES] Las conexiones de acceso a Internet de banda ancha permiten a los Internet Service Provider (ISP) ofrecer servicios a los hogares tales como datos, Voice on IP (VoIP), Televisión sobre IP (IPTV) y actualmente 3D-TV sobre IP (3D-IPTV). Es por esto que el número de proveedores de servicios de IPTV está aumentando considerable- mente en los últimos años. Gracias a la evolución tanto a nivel de sistemas, como de redes de comunicación como de dispositivos, la entrega de este tipo de servicios es posible pero no siempre con las máximas garantías de calidad. Por este motivo, una de las principales cuestiones a tener en cuenta por parte del proveedor de servicios de IPTV es garantizar la calidad de experiencia (Quality of Experience (QoE)) percibida por el usuario final. Para conseguir este objetivo, en la siguiente tesis doctoral se propone un sistema de gestión inteligente basado en métodos induc- tivos de predicción para garantizar la QoE del usuario final. Uno de los aspectos importantes a tener en cuenta en el desarrollo del sistema de gestión es el incluir los parámetros que afectan a la QoE. Para ello, se analizarán aquellos parámetros que afecten a la degradación del flujo de vídeo recibido por el usuario final a tra- vés del servicio de IPTV. A nivel de red, se identificarán dichos parámetros como aquellos que afectan a la calidad de Servicio (Quality of Service (QoS)) como son el jitter, el retardo, los paquetes perdidos y el ancho de banda principalmente. A nivel de usuario, estos parámetros afectan a la percepción subjetiva del usuario al visualizar el vídeo. Comprobamos como efectos derivados de la compresión, la cuantificación, el bitrate, etc, afectan también a dicha percepción. / [CAT] Les connexions d'accés a Internet de banda ampla permeten als Proveïdors de Ser- vicis d'Internet (ISP) oferir servicis a les llars com ara dades, veu sobre IP (VoIP), Televisió sobre IP (IPTV) i actualment 3D-TV sobre IP (3D-IPTV). És per açò que el nombre de proveïdors de servicis d'IPTV està augmentant considerablement en els últims anys. Gràcies a l'evolució tant a nivell de sistemes, com de xarxes de comunicació com de dispositius, l'entrega d'este tipus de servicis és possible però no sempre amb les màximes garanties de qualitat. Per este motiu, una de les principals qüestions a tindre en compte per part del proveïdor de servicis d'IPTV és garantir la qualitat d'experiència (Quality of Experience, QoE) percebuda per l'usuari final. Per a aconseguir este objectiu, en la següent tesi doctoral es proposa un sistema de gestió intel·ligent basat en mètodes inductius de predicció per a garantir la QoE de l'usuari final. Un dels aspectes importants a tindre en compte en el desenrotllament del sistema de gestió es incloure els paràmetres que afecten la QoE. Per a això, s'analitzaran aquells paràmetres que afecten la degradació del flux de vídeo rebut per l'usuari final a través del servici d'IPTV. A nivell de xar- xa, s'identificaran dits paràmetres com aquells que afecten la qualitat de Servici (Quality of Service, QoS) com són el jitter, el retard, els paquets perduts i l'ample de banda principalment. A nivell d'usuari, estos paràmetres afecten la percepció subjectiva de l'usuari al visualitzar el vídeo. Comprovem com efectes derivats de la compresió, la quantificació, el bitrate, etc, afecten també a dita percepció. / Cánovas Solbes, A. (2016). Diseño y Desarrollo de un Sistema de Gestión Inteligente de QoE para Redes HD y Estereoscópicas IPTV [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/65074 / TESIS

Cloud gaming over mobile networks enables players to play high-resource consuming games on low-end devices with various intrinsic restrictions such as limited battery lifetime and computational capacity. For mobile cloud gaming(MCG), the remaining battery level on the device is one of the critical factors that affect the sensitivity of user satisfaction. Thus, an android application is developed to measure the energy consumption of mobile devices that measure the power consumption of the device such that the obtained values correspond with the specific network conditions and users. The collected values are studied to identify if the energy consumption of the device is impacted by the network degradation that might occur during MCG in cellular networks. Results demonstrate that the energy consumption is at its highest when packet loss is 45% at 2ms RoundTrip Time (RTT) delay. Moreover, a qualitative study on the perceived Quality of Experience (QoE) of MCG over mobile networks is conducted and its impact on the energy consumption of the device is investigated where 31 users play a cloud-based First Person Shooter (FPS) for approximately 2 hours each. The results demonstrate the existence of the relationship between energy consumption and perceived QoE whereas negates the hypothesis of the existence of the relationship between QoE and CPU resources. In addition, to make comparisons of energy consumption of MCG with online mobile gaming (OMG), another test is carried out where each user plays another non-cloud-based FPS game and it is found that MCG is more efficient than OMG under the least energy-consuming network condition (2ms RTT delay) by 33.3% and the most energy consuming network condition (45% packet loss at 2ms RTT) by 32.7% in 4G cellular network.

The use of audio and video communication has increased exponentially over the last decade and has gone from speech over GSM to HD resolution video conference between continents on mobile devices. As the use becomes more widespread the interest in delivering high quality media increases even on devices with limited resources. This includes both development and enhancement of the communication chain but also the topic of objective measurements of the perceived quality. The focus of this thesis work has been to perform enhancement within speech encoding and video decoding, to measure influence factors of audio and video performance, and to build methods to predict the perceived video quality. The audio enhancement part of this thesis addresses the well known problem in the GSM system with an interfering signal generated by the switching nature of TDMA cellular telephony. Two different solutions are given to suppress such interference internally in the mobile handset. The first method involves the use of subtractive noise cancellation employing correlators, the second uses a structure of IIR notch filters. Both solutions use control algorithms based on the state of the communication between the mobile handset and the base station. The video enhancement part presents two post-filters. These two filters are designed to improve visual quality of highly compressed video streams from standard, block-based video codecs by combating both blocking and ringing artifacts. The second post-filter also performs sharpening. The third part addresses the problem of measuring audio and video delay as well as skewness between these, also known as synchronization. This method is a black box technique which enables it to be applied on any audiovisual application, proprietary as well as open standards, and can be run on any platform and over any network connectivity. The last part addresses no-reference (NR) bitstream video quality prediction using features extracted from the coded video stream. Several methods have been used and evaluated: Multiple Linear Regression (MLR), Artificial Neural Network (ANN), and Least Square Support Vector Machines (LS-SVM), showing high correlation with both MOS and objective video assessment methods as PSNR and PEVQ. The impact from temporal, spatial and quantization variations on perceptual video quality has also been addressed, together with the trade off between these, and for this purpose a set of locally conducted subjective experiments were performed.

Speech as a medium for communication has always been important in its ability to convey our ideas, personality and emotions. It is therefore not strange that Quality of Experience (QoE) becomes central to any business relying on voice communication. Using Unified Communication (UC) systems, users can communicate with each other in several ways using many different devices, making QoE an important aspect for such systems. For this thesis, automatic methods for assessing speech quality of the voice calls in Briteback’s UC application is studied, including a comparison of the researched methods. Three methods all using a Gaussian Mixture Model (GMM) as a regressor, paired with extraction of Human Factor Cepstral Coefficients (HFCC), Gammatone Frequency Cepstral Coefficients (GFCC) and Modified Mel Frequency Cepstrum Coefficients (MMFCC) features respectively is studied. The method based on HFCC feature extraction shows better performance in general compared to the two other methods, but all methods show comparatively low performance compared to literature. This most likely stems from implementation errors, showing the difference between theory and practice in the literature, together with the lack of reference implementations. Further work with practical aspects in mind, such as reference implementations or verification tools can make the field more popular and increase its use in the real world.

Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-07-30T16:35:12Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_CrossLayerOptimizations.pdf: 20257418 bytes, checksum: 96559fd5f83b5752bc63ce073eb1c700 (MD5) / Rejected by Edisangela Bastos (edisangela@ufpa.br), reason: on 2014-07-30T16:37:23Z (GMT) / Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-07-30T16:41:46Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_CrossLayerOptimizations.pdf: 20257418 bytes, checksum: 96559fd5f83b5752bc63ce073eb1c700 (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-09-04T14:34:02Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_CrossLayerOptimizations.pdf: 20257418 bytes, checksum: 96559fd5f83b5752bc63ce073eb1c700 (MD5) / Made available in DSpace on 2014-09-04T14:34:02Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_CrossLayerOptimizations.pdf: 20257418 bytes, checksum: 96559fd5f83b5752bc63ce073eb1c700 (MD5) Previous issue date: 2014 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / University of Bern / A proliferação de conteúdo multimídia bem como a demanda por novos serviços de áudio ou vídeo promoveram o desenvolvimento de uma nova era baseada em informações multimídia, o que permitiu a evolução das Redes de Sensores Sem Fio Multimídia (RSSFM) e também das redes ad-hoc desenvolvimento formadas por VANTs (FANETs). Desta forma, serviços multimídia em tempo real requerem transmissões de vídeo em tempo real com uma baixa taxa de perda de quadros, atraso fim-a-fim tolerável, para apoiar a disseminação de vídeo com qualidade de Experiência (QoE) assegurada. Desta forma, um princípio fundamental de uma abordagem ciente de QoE é a transmissão de quadros de vídeo com alta prioridade, baixa taxa de perda de pacotes, bem como baixa sobrecarga da rede, a fim de protegê-los. Além disso, o conteúdo multimídia devem ser transmitidos a partir de um determinado nó de origem para um nó de destino através de nós intermediários com alta confiabilidade em um cenário de grande escala. O serviço de roteamento deve lidar com topologias dinâmicas causadas por falha de um nó ou a mobilidade do mesmo, bem como as mudanças no canal sem fio, a fim de continuar a operar mesmo em casos de mudanças de topologia durante a transmissão multimídia. Por fim, o mapeamento da satisfação do usuário ao assistir um determinado vídeo está se tornando um requisito fundamental para a entrega de conteúdos multimídia com suporte à QoE. Com estes objetivos em mente, soluções envolvendo transmissões multimídia deve levar em conta as características de vídeo e do usuário para melhorar a entrega de vídeo com qualidade assegurada. As principais contribuições desta tese são conduzidos pela seguinte questão de pesquisa: como para fornecer distribuição de multimídia com alta eficiência energética, confiabilidade, robustez, escalabilidade e suporte à QoE em redes sem fio ad hoc. A tese aborda vários domínios de problemas com contribuições em diferentes camadas da pilha de comunicação. Na camada de aplicação, apresentamos um mecanismo de redundância de pacotes ciente de QoE para reduzir o impacto da não confiabilidade do canal sem fio, e assim prover disseminação de conteúdo multimídia em tempo real com suporte à QoE. Na camada de rede, apresentamos dois protocolos de roteamento, ou seja, o video-aware Multi-hop and multi-path hierarchical routing protocol for Efficient VIdeo transmission for static WMSN scenarios (MEVI) e o cross-layer link quality and geographical-aware beaconless OR protocol for multimedia FANET scenarios (XLinGO). Ambos os protocolos de roteamento permitem a disseminação de conteúdo multimídia com eficiência energética, confiabilidade e suporte à QoE. Isto é alcançado através da combinação de métricas de múltiplas camadas para a tomada de decisão para o roteamento de pacotes, e assim estabelecer rotas confiáveis. / The proliferation of multimedia content and the demand for new audio or video services have fostered the development of a new era based on multimedia information, which allowed the evolution of Wireless Multimedia Sensor Networks (WMSNs) and also Flying Ad-Hoc Networks (FANETs). In this way, live multimedia services require realtime video transmissions with a low frame loss rate, tolerable end-to-end delay, and jitter to support video dissemination with Quality of Experience (QoE) support. Hence, a key principle in a QoE-aware approach is the transmission of high priority frames (protect them) with a minimum packet loss ratio, as well as network overhead. Moreover, multimedia content must be transmitted from a given source to the destination via intermediate nodes with high reliability in a large scale scenario. The routing service must cope with dynamic topologies caused by node failure or mobility, as well as wireless channel changes, in order to continue to operate despite dynamic topologies during multimedia transmission. Finally, understanding user satisfaction on watching a video sequence is becoming a key requirement for delivery of multimedia content with QoE support. With this goal in mind, solutions involving multimedia transmissions must take into account the video characteristics to improve video quality delivery. The main research contributions of this thesis are driven by the research question how to provide multimedia distribution with high energy-efficiency, reliability, robustness, scalability, and QoE support over wireless ad hoc networks. The thesis addresses several problem domains with contributions on different layers of the communication stack. At the application layer, we introduce a QoE-aware packet redundancy mechanism to reduce the impact of the unreliable and lossy nature of wireless environment to disseminate live multimedia content. At the network layer, we introduce two routing protocols, namely video-aware Multi-hop and multi-path hierarchical routing protocol for Efficient VIdeo transmission for static WMSN scenarios (MEVI), and cross-layer link quality and geographical-aware beaconless OR protocol for multimedia FANET scenarios (XLinGO). Both protocols enable multimedia dissemination with energy-efficiency, reliability and QoE support. This is achieved by combining multiple cross-layer metrics for routing decision in order to establish reliable routes.

The telecommunication market is growing at a very fast pace with the evolution of new technologies to support high speed throughput and the availability of a wide range of services and applications in the mobile networks. This has led to a need for communication service providers (CSPs) to shift their focus from network elements monitoring towards services monitoring and subscribers’ satisfaction by introducing the service quality management (SQM) and the customer experience management (CEM) that require fast responses to reduce the time to find and solve network problems, to ensure efficiency and proactive maintenance, to improve the quality of service (QoS) and the quality of experience (QoE) of the subscribers. While both the SQM and the CEM demand multiple information from different interfaces, managing multiple data sources adds an extra layer of complexity with the collection of data. While several studies and researches have been conducted for data analytics in mobile networks, most of them did not consider analytics based on the four dimensions involved in the mobile networks environment which are the subscriber, the handset, the service and the network element with multiple interface correlation. The main objective of this research was to develop mobile network analytics models applied to the 3G packet-switched domain by analysing data from the radio network with the Iub interface and the core network with the Gn interface to provide a fast root cause analysis (RCA) approach considering the four dimensions involved in the mobile networks. This was achieved by using the latest computer engineering advancements which are Big Data platforms and data mining techniques through machine learning algorithms. / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)

Quality of Experience (QoE) is the degree of delight or annoyance of the user of an application or service [1]. To ensure a proper level of QoE for end users, networks and service providers have to continuously monitor their systems in terms of technical parameters, which can then be used to estimate QoE. Especially for video streaming services, which consume a large amount of traffic, network problems such as bandwidth fluctuations quickly develop into annoying artefacts visible to the users, which may lead to abandonment of services. Internet Service Providers (ISPs) are therefore continuously monitoring video network streams in order to provide the better QoE. In this regard to conduct the user behavioral studies, the ISPs spend a large amount of money and energy every time. To avoid this, we are using existing user behavioral studies and simulating the user behavior in an automated set-up and try to measure the impact of network conditions. In our current studies based on the user-behavioral model used [5], we can conclude that low upload speeds don’t affect on simulated user behavior unless they are in high download speed networks. Simulated users with the mid-range download and upload bandwidth tend to face more stalling and quality switches compared to both low and high-bandwidth users. Key quality indicators(KQIs) of video QoE also depends on the number of videos we measure in a single session. Reloading of player helps to reduce stalling for mid and high bandwidths. Reloading worsens the situation in low bandwidth scenarios. / Kvalitet av erfarenhet (QoE) definieras som: "Graden av fröjd eller förargelse av användaren av en applikation eller en service. Den resulterar från uppfyllelsen av hans eller hennes förväntningar med hänsyn till hjälpmedlet, och/eller njutning av applikationen eller servicen i ljuset av användarens personlighet och aktuella tillstånd" [1]. Att att se till en riktig nivå av QoE för slut användare, nätverk och tjänstefamiljeförsörjare måste övervakar fortlöpande deras system när det gäller tekniska parametrar, som kan därefter vara den van vid bedömningen QoE. Speciellt för videoen som strömmar service, som konsumerar ett stort belopp av trafik, framkallar nätverksproblem liksom bandbreddväxlingar snabbt in i förargliga artefacts som är synliga till användarena, som kan leda till övergivande av service. Internetleverantörer (ISPs) är därför fortlöpande videopp nätverksströmmar för övervakning för att att ge den bättre QoEen. I detta avseende att föra de beteendestudierna för användaren, spenderar ISPsna en stor mängd pengar och energi varje gång. Att undvika denna, använder simulerar vi beteendestudier för existerande användare och användareuppförandet i en automatiserat aktivering och försök för att mäta inverkan av nätverksvillkor. I våra aktuella studier som baseras på den använda användare-beteendemodellen [5], oss kan avsluta som laddar upp lågt hastigheter inte påverkar på simulerat användareuppförande, om inte de är i höga nedladdninghastighetsnätverk. Simulerade användare med mitt–området nedladdar och laddar upp bandbredd ansar för att vända mot mer avbrottsoch kvalitetsströmbrytare som jämförs till både låga och höga bandbreddanvändare. Nyckelkvalitetsindikatorer (KQIs) av video QoE beror också på numret av video som vi mäter i en enkel period. Tillbakaläggande av spelaren hjälper att förminska avbrott för mittoch höga bandbredder. Tillbakaläggande försämrar läget i scenarion för låg bandbredd.