Video on demand (VoD) services are becoming more and more popular today. As high bandwidth communication infrastructure is being established in many countries around the world, high bandwidth communication lines will reach millions of family in the near future. Due to the increasing improvement of communication technology, more and more families enjoy the VoD services which are provided by telecommunication companies and cable TV provider via the Internet. In such a case, scalability and fault tolerance will be the key issues. We propose an architecture for VoD services which is based on multi-server circumstance. In our proposed architecture, each movie is replicated on a subset of the servers. When a server crashes or disconnects from its clients, it is replaced by another server in a transparent way. Regarding of load balancing problem, clients are also migrated from one server to another when a new server is brought up. The benefit of our service is to use common hardware and general network technologies (e.g. TCP/IP). In addition, we provide a machine-independent environment to let the servers and clients execute on any machine through the network. Furthermore, we can get the media players from a web browser by utilizing the cross-platform characteristics of Java. The client host does not need to install any relevant applications. Since Java Media Framework (JMF) provides a unified architecture and messaging protocol for managing the acquisition, processing, and delivery of time-based media data. It can support many standard media content types, such as AIFF, AVI, MIDI, MPEG, QuickTime, and WAV. Using JMF, we can create applets and applications to present, manipulate, and store time-based media.

Syfte: Vi vill ta reda på hur teknikutvecklingen relaterad till VoD påverkar beteendet hos unga vuxna och hur detta beteende förändrar tv-tittandet i denna målgrupp. Teori: Denna studie använder huvudsakligen två teorier för att undersöka problemet. Den första teori som tas upp är Diffusion of innovation, Rogers (2003) som diskuterar innovationers spridning och påverkan i samhället. För att vidare undersöka beteendet hos unga vuxna används Jakob Bjurs avhandling Transforming Audiences (2009) som undersöker individualiseringens mönster inom tv-tittande. Metod: En kvalitativ empirisk fallstudie baserad på intervjuer av fokusgrupper samt personintervju. Detta stöds av en kvantitativ undersökning i syfte att skapa en triangulering för att minimera risken för en felaktig tolkning av resultatet. Resultat: Unga vuxna vill inte längre anpassa sig till tv-tablåer. Generationen blir allt mer individualiserad och vill därför välja helt på egen hand var och när de skall titta på exempelvis ett tv-program. Medieföretagen är medvetna om detta skifte från linjär-tv till VoD och således finns ett fokus på att utveckla ett mer individ-anpassat tittande. Trots individualiseringen och de förbättrade VoD-tjänsterna vill många se bland annat nyheter, större sportevenemang samt melodifestivalen via linjär-tv. Slutsats: Den största anledningen till att många gör denna övergång från linjär-tv till VoD är att de söker en flexibilitet som linjär-tv inte kan erbjuda. Flexibiliteten har gjorts möjlig genom den teknikutveckling som skett inom datorer, smarttelefoner och surfplattor. Det som lockar många VoD-användare till att fortfarande titta på linjär-tv är de sändningar som är viktiga att se i realtid. Tack vare dessa kommer förmodligen tv-tittandet finnas kvar en tid framöver, dock ser vi sjunkande tittarsiffror i de yngre generationerna vilket gör framtiden för linjär-tv oviss.

Syfte: Studien syftar till att få en djupare förståelse i hur användarens tittarvanor påverkas av Netflix design och teknik, och huruvida dessa uppmuntrar användaren till Binge Watching. Teori: Studien använder sig främst av Sidneyeve Matrix (2014) teori och forskning om det tekniska fenomenet Binge Watching från artikeln “The Netflix Effect: Teens, Binge Watching and on Demand Media Trends” samt Jonas Löwgrens (2002) teori om kvalitet på användning från artikeln “The use qualities of digital designs, draft 1.0”. Även Gunnar Nygren och Ingela Wadbrings (2013) forskning om den tekniska utvecklingen från publikationen “På väg mot medievärlden 2020” används i undersökningen. Metod: Studien utgår från en kvalitativ forskningsmetod baserad på enskilda djupgående intervjuer. Resultat: Resultatanalysen indikerar att Netflix teknik och funktioner har en stor påverkan på användaren och dess tittarvanor. Informanterna upplever att de utan dessa funktioner inte hade använt tjänsten i lika stor utsträckning och att en lojalitet och känslomässig hängivenhet upprättats efter Netflix många taktiker att förbättra den personliga användarupplevelsen. De tekniska funktionerna har även resulterat i att samtliga informanter kontinuerligt Binge Watchar och inte sällan ser fler avsnitt av en serie än från början tänkt. / Purpose: The study aims to gain a deeper understanding of how the users viewing habits are influenced by Netflix design and technology, and whether they encourage the user to Binge Watching. Theory: The study mainly uses the theory and research by Sidneyeve Matrix (2014) on the technical phenomenon Binge Watching from the article “The Netflix Effect: Teens, Binge Watching and on Demand Media Trends” and the theory about the use qualities by Jonas Löwgren (2002) from the article “The use qualities of digital designs, draft 1.0”. The research on technological developments by Gunnar Nygren and Ingela Wadbring (2013) from the publication “På väg mot medievärlden 2020” is also used in this study. Method: The study is based on a qualitative research method based on individual in-depth interviews. Results: The result analysis indicates that Netflix technologies and features have a transparent impact on users and their viewing habits. The informants felt that they without these features would not have used the service to the same extent and that loyalty and emotional commitment was established due to the many tactics Netflix used to improve the personal user experience. The technical features have also resulted in an increased Binge Watching for all of the informants who also often view more episodes of a series than originally thought. It also became clear that it was the technology, features and wider range that made Netflix the most preferred VoD service among the informants.

With the expansion of the Internet and an increasing fraction of consumers having broadband connections, more and more content is finding its way on-line. Video content is becoming one of the most popular types of media content on the Internet. Traditional media content providers, such as television networks, are placing their content on the Internet in order to gain a broader audience. On-demand websites such as kanal5play.se allow viewers to view the multimedia content they want at the time of their choice. While this gives viewers flexibility in their viewing, it creates resource problems for content providers. Statistics from Kanal5 AB show that, even with individual viewers requesting content when they want, there are still patterns in which multiple viewers watch the same content at the same time. This means there are correlations in the demand for content. With unicast distribution this leads to spikes in requirements for bandwidth to the viewers. These peaks lead to high costs for network and server resources to deliver the requested content, but these resources have low average utilization. This thesis project investigates how a content provider can make use of each viewer’s own resources to deliver content to other users using peer-to-peer techniques. The thesis evaluates what methods can be used in order to reduce the content provider’s resource requirements during peak hours by exploiting copies of contents that have already been delivered to viewers who requested this same content earlier. A prototype was made to evaluate the suggested design using Java Remote Method Invocation (RMI), which is built on top of the Transfer Control Protocol (TCP). Experiments show that an initial delay of several seconds is reached on a network with a simulated delay of 100ms, while a minimal initial delay was observed on a network with low delay, i.e. ideal conditions. The throughput results of the prototype show that the suggested solution is adequate for delivering on-demand content supplied by Kanal5 AB. However, the relatively poor startup performance of this solution argues for tuning the application to better work with the TCP protocol or to utilize another transport protocol - especially if the round-trip delay is large as TCP’s 3-way handshake and flow control algorithm limit the performance of the prototype system. / Med utbyggnaden av Internet och en ökande andel konsumenter med bredband, mer och mer innehåll hittar sin väg på nätet. Video innehåll blir en av de mest populära typer av media på Internet. Innehållsleverantörer som använder sig av traditionella medier, exempelvis tv-nät, lägger sitt innehåll på Internet för att nå en bredare publik. On-demand webbplatser som kanal5play.se låter tittarna se multimediainnehållet de vill, när de vill. Även om detta ger tittarna flexibilitet i sitt tittande så skapar det resursproblem för innehållsleverantörer. Statistik från Kanal5 AB visar att även med enskilda tittare som begär innehåll när de vill så finns det fortfarande mönster där flera tittare tittar på samma innehåll på samma gång. Detta innebär att det finns samband i efterfrågan på innehåll. Med unicast distribution leder detta till sprikar i krav på bandbredd till tittarna. Dessa toppar leda till höga kostnader för nät-och server för att leverera det efterfrågade innehållet, men dessa resurser har låga genomsnittliga utnyttjanden. Detta examensarbete undersöker hur en innehållsleverantör kan använda sig av varje tittares egna resurser för att leverera innehåll till andra användare med hjälp av peer-to-peer-teknik. Avhandlingen utvärderar vilka metoder kan användas för att minska innehållsleverantörens resursbehov under rusningstid genom att utnyttja kopior av innehåll som redan har levererats till tittarna som begärde samma innehåll tidigare. En prototyp gjordes för att utvärdera den föreslagna konstruktionen med Java Remote Method Invocation (RMI), som är byggd ovanpå Transfer Control Protocol (TCP). Experiment visar en uppstartsfördröjning på flera sekunder på ett nätverk med en simulerad fördröjning på 100 ms, samtidigt som en minimal uppstartsfördöjning observerades på ett nätverk med låg fördröjning, dvs idealiska förhållanden. Resultaten för genomströmningshastigheten hos prototypen visar att den föreslagna lösningen är tillräcklig för att leverera on-demand innehåll som tillhandahålls av Kanal5 AB. De relativt dåliga uppstartsresultaten för denna lösning säger dock att förbättringar bör göras i applikationen så att den kan arbeta bättre med TCP protokollet, eller att ett annat protokoll används - särskilt om nätverksfördröjningen är stor, då TCP:s 3-vägs handskakning och flödeskontroll algoritm begränsar prestandan hos det föreslagna systemet.

Com o aumento da concorrência sofrido pelas operadoras de telecomunicações frente à entrada de diversas empresas de outros ramos no mercado de comunicação, como, por exemplo, os Provedores de Serviço de Internet (ISPs - Internet Service Providers) através da oferta de serviços de voz sobre IP, tais operadoras viram-se obrigadas a diversificar sua oferta de serviços para gerar novas fontes de receita. Por possuírem ampla infra-estrutura instalada, as operadoras de telecomunicações passaram a oferecer, também, serviço de TV aos usuários, através de suas redes (convergentes) de telefonia e dados já existentes, o chamado IPTV. O objetivo deste trabalho foi possibilitar, neste cenário, que estas empresas consigam oferecer, além dos serviços convencionais de TV (e.g., transmissões lineares dos conteúdos nos canais de TV), serviços diferenciados empregando-se a mesma infra-estrutura. O foco deste trabalho é a oferta do serviço de apresentação deslocada no tempo dos conteúdos transmitidos linearmente nos canais de TV, sem a necessidade de configuração prévia por parte do usuário. Desta maneira, dá-se maior flexibilidade ao usuário, possibilitando-o assistir aos conteúdos que lhe interessam, no horário mais conveniente, sem ter que se preocupar com isso antecipadamente (i.e., sem a necessidade de configurar algum equipamento para gravar o conteúdo ou saber antecipadamente quais programas lhe interessam). Para isso foram pesquisadas e analisadas tanto tecnologias de transmissão e distribuição de conteúdos, como também o paradigma peer-to-peer, muito utilizado atualmente no compartilhamento de arquivos na Internet. A partir daí, foi concebida uma arquitetura capaz de oferecer tanto o serviço tradicional de transmissão linear de TV, quanto de apresentar vídeos deslocados no tempo (i.e., vídeos cuja transmissão linear já foi iniciada ou até concluída, a partir de qualquer posição já transmitida), combinando-se técnicas de multidifusão de dados, armazenamento distribuído e protocolos peer-to-peer. Desta maneira, obteve-se uma solução eficiente, utilizando-se os recursos disponíveis em todo o sistema, incluindo recursos ociosos dos usuários finais, para auxiliar no armazenamento e distribuição dos conteúdos deslocados no tempo. Finalmente, um protótipo foi desenvolvido como prova de conceito da arquitetura proposta neste trabalho, e, juntamente com os testes realizados, comprovam a viabilidade de se utilizar redes P2P para a distribuição dos conteúdos para a apresentação deslocada no tempo. / Telecommunication companies are suffering from the increasing offer of cheap and reliable voice over IP services, being forced to diversify their services looking for new revenue possibilities. Since these companies have a vast infrastructure, they are now providing TV services through the same telephony and data infrastructure, using their IP networks to offer IPTV. The goal of the present work is to allow, in this scenario, that such companies offer, additionally to the traditional TV services (e.g., the linear transmissions of the TV channels), differentiated services through the same infrastructure. The focus of the present work is, therefore, the offering of the time-shift service, allowing users to watch linear transmitted contents, time-shifted, without the need for any in-advance configuration. This approach gives more flexibility to the users, allowing them to choose the most appropriate time to watch some content without having to specify their interests in advance (i.e., without configuring some equipment to record the content or knowing in advance which programs will interest themselves). To achieve this goal, technologies for content transmission and distribution, as well as the peer-to-peer paradigm for file sharing were studied, resulting in the development of an architecture capable of offering the traditional linear transmissions service as well as the possibility of time-shift, combining multicast, distributed caching and peer-to-peer technologies. Accordingly, an efficient solution was envisioned, making use of all available resources in the system, including idle resources in the user equipments, to help in the caching and distribution of the time-shifted contents. Finally, a prototype was developed as a proof-of-concept for the designed architecture, which together with the performed tests, shows the viability of utilizing P2P networks in the distribution of time-shifted contents.

Com o aumento da concorrência sofrido pelas operadoras de telecomunicações frente à entrada de diversas empresas de outros ramos no mercado de comunicação, como, por exemplo, os Provedores de Serviço de Internet (ISPs - Internet Service Providers) através da oferta de serviços de voz sobre IP, tais operadoras viram-se obrigadas a diversificar sua oferta de serviços para gerar novas fontes de receita. Por possuírem ampla infra-estrutura instalada, as operadoras de telecomunicações passaram a oferecer, também, serviço de TV aos usuários, através de suas redes (convergentes) de telefonia e dados já existentes, o chamado IPTV. O objetivo deste trabalho foi possibilitar, neste cenário, que estas empresas consigam oferecer, além dos serviços convencionais de TV (e.g., transmissões lineares dos conteúdos nos canais de TV), serviços diferenciados empregando-se a mesma infra-estrutura. O foco deste trabalho é a oferta do serviço de apresentação deslocada no tempo dos conteúdos transmitidos linearmente nos canais de TV, sem a necessidade de configuração prévia por parte do usuário. Desta maneira, dá-se maior flexibilidade ao usuário, possibilitando-o assistir aos conteúdos que lhe interessam, no horário mais conveniente, sem ter que se preocupar com isso antecipadamente (i.e., sem a necessidade de configurar algum equipamento para gravar o conteúdo ou saber antecipadamente quais programas lhe interessam). Para isso foram pesquisadas e analisadas tanto tecnologias de transmissão e distribuição de conteúdos, como também o paradigma peer-to-peer, muito utilizado atualmente no compartilhamento de arquivos na Internet. A partir daí, foi concebida uma arquitetura capaz de oferecer tanto o serviço tradicional de transmissão linear de TV, quanto de apresentar vídeos deslocados no tempo (i.e., vídeos cuja transmissão linear já foi iniciada ou até concluída, a partir de qualquer posição já transmitida), combinando-se técnicas de multidifusão de dados, armazenamento distribuído e protocolos peer-to-peer. Desta maneira, obteve-se uma solução eficiente, utilizando-se os recursos disponíveis em todo o sistema, incluindo recursos ociosos dos usuários finais, para auxiliar no armazenamento e distribuição dos conteúdos deslocados no tempo. Finalmente, um protótipo foi desenvolvido como prova de conceito da arquitetura proposta neste trabalho, e, juntamente com os testes realizados, comprovam a viabilidade de se utilizar redes P2P para a distribuição dos conteúdos para a apresentação deslocada no tempo. / Telecommunication companies are suffering from the increasing offer of cheap and reliable voice over IP services, being forced to diversify their services looking for new revenue possibilities. Since these companies have a vast infrastructure, they are now providing TV services through the same telephony and data infrastructure, using their IP networks to offer IPTV. The goal of the present work is to allow, in this scenario, that such companies offer, additionally to the traditional TV services (e.g., the linear transmissions of the TV channels), differentiated services through the same infrastructure. The focus of the present work is, therefore, the offering of the time-shift service, allowing users to watch linear transmitted contents, time-shifted, without the need for any in-advance configuration. This approach gives more flexibility to the users, allowing them to choose the most appropriate time to watch some content without having to specify their interests in advance (i.e., without configuring some equipment to record the content or knowing in advance which programs will interest themselves). To achieve this goal, technologies for content transmission and distribution, as well as the peer-to-peer paradigm for file sharing were studied, resulting in the development of an architecture capable of offering the traditional linear transmissions service as well as the possibility of time-shift, combining multicast, distributed caching and peer-to-peer technologies. Accordingly, an efficient solution was envisioned, making use of all available resources in the system, including idle resources in the user equipments, to help in the caching and distribution of the time-shifted contents. Finally, a prototype was developed as a proof-of-concept for the designed architecture, which together with the performed tests, shows the viability of utilizing P2P networks in the distribution of time-shifted contents.