Design And Analysis Of Scalable Video Streaming Systems

Despite the advancement in multimedia streaming technology, many multimedia applications are still face major challenges, including provision of Quality-of-Service (QoS), system scalability, limited resources, and cost. In this dissertation, we develop and analyze a new set of metrics based on two particular video streaming systems, namely: (1) Video-on-Demand (VOD) with video advertisements system and (2) Automated Video Surveillance System (AVS). We address the main issues in the design of commercial VOD systems: scalability and support of video advertisements. We develop a scalable delivery framework for streaming media content with video advertisements. The delivery framework combines the benefits of stream merging and periodic broadcasting. In addition, we propose new scheduling policies that are well-suited for the proposed delivery framework. We also propose a new prediction scheme of the ad viewing times, called Assign Closest Ad Completion Time (ACA). Moreover, we propose an enhanced business model, in which the revenue generated from advertisements is used to subsidize the price. Additionally, we investigate the support of targeted advertisements, whereby clients receive ads that are well-suited for their interests and needs. Furthermore, we provide the clients with the ability to select from multiple price options, each with an associate expected number of viewed ads. We provide detailed analysis of the proposed VOD system, considering realistic workload and a wide range of design parameters. In the second system, Automated Video Surveillance (AVS), we consider the system design for optimizing the subjects recognition probabilities. We focus on the management and the control of various Pan, Tilt, Zoom (PTZ) video cameras. In particular, we develop a camera management solution that provides the best tradeoff between the subject recognition probability and time complexity. We consider both subject grouping and clustering mechanisms. In subject grouping, we propose the Grid Based Grouping (GBG) and the Elevator Based P lanning (EBP) algorithms. In the clustering approach, we propose the (GBG) with Clustering (GBGC) and the EBP with Clustering (EBPC) algorithms. We characterize the impact of various factors on recognition probability. These factors include resolution, pose and zoom-distance noise. We provide detailed analysis of the camera management solution, considering realistic workload and system design parameters

Screen real estate ownership based mechanism for negotiating advertisement display

As popularity of online video grows, a number of models of advertising are emerging. It is typically the brokers – usually the operators of websites – who maintain the balance between content and advertising. Existing approaches focus primarily on personalizing advertisements for viewer segments, with minimal decision-making capacity for individual viewers. We take a resource ownership view on this problem. We view consumers’ attention space, which can be abstracted as a display screen for an engaged viewer, as precious resource owned by the viewer. Viewers pay for the content they wish to view in dollars, as well as in terms of their attention. Specifically, advertisers may make partial payment for a viewer’s content, in return for receiving the viewer’s attention to their advertising. Our approach, named “FlexAdSense”, is based on CyberOrgs model, which encapsulates distributed owned resources for multi-agent computations. We build a market of viewers’ attention space in which advertisers can trade, just as viewers can trade in a market of content. We have developed key mechanisms to give viewers flexible control over the display of advertisements in real time. Specific policies needed for automated negotiations can be plugged-in. This approach relaxes the exclusivity of the relationship between advertisers and brokers, and empowers viewers, enhancing their viewing experience. This thesis presents the rationale, design, implementation, and evaluation of FlexAdSense. Feature comparison with existing advertising mechanisms shows how FlexAdSense enables viewers to control with fine-grained flexibility. Experimental results demonstrate the scalability of the approach, as the number of viewers increases. A preliminary analysis of user overhead illustrates minimal attention overhead for viewers as they customize their policies

Peer-to-Peer Networks and Computation: Current Trends and Future Perspectives

This research papers examines the state-of-the-art in the area of P2P networks/computation. It attempts to identify the challenges that confront the community of P2P researchers and developers, which need to be addressed before the potential of P2P-based systems, can be effectively realized beyond content distribution and file-sharing applications to build real-world, intelligent and commercial software systems. Future perspectives and some thoughts on the evolution of P2P-based systems are also provided

Converged video delivery over heterogeneous networks

Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 91-96).Mobile traffic has grown substantially over the last few years; a trend which is expected to continue. The chief reasons behind this phenomenon are the availability of better handsets, faster cellular networks and the variety of content available on the internet suitable for consumption on mobile devices. The nature of the traffic is also changing from pure web browsing with latency-tolerant traffic to video, which is becoming the major class of content consumed on mobile devices. This trend, combined with the trend of decreasing prices per GB of data, which constrains the amount of money an operator can spend upgrading its network and they see increasing value in alternative solutions to address this data deluge while managing costs and maintaining customer service. A variety of solutions have been tried by operators based on enhanced charging, traffic engineering and backhaul infrastructure upgrades. Wi-Fi offload is one such promising solution as it addresses the congestion problem where it is most severe because of data consumption by users using streaming video. Cellular spectrum is a scarce and expensive resource for operators, and by allowing them to offload traffic to Wi-Fi networks in unlicensed spectrum they can free cellular spectrum for more valuable applications. Wi-Fi offload has, however, suffered from the incapability to manage seamless handovers and the required interaction of the user to select a Wi-Fi network. This made the process of attaching to a Wi-Fi network very complicated. These limitations have been addressed in recent standards and make the case for Wi-Fi offload more viable and attractive than earlier. At the same time new video optimization techniques such as H.264/SVC which allow the use of multiple streams and channel will allow content providers or distributors to use multiple networks and to scale video seamlessly according to handset capabilities and network conditions. The thesis proposes a solution, based on a set of new Wi-Fi standards and the new H.264/AVC codecs, which leverages a combination of low cost Wi-Fi and high reliability cellular networks to reduce the cost of video transmission while maintaining a comparable QOE for nomadic users. The thesis also enumerates some of the basic procedures that can be supported using the proposed architecture. This new architecture opens new opportunities for existing players in the mobile content ecosystem and adds new players to the ecosystem. The thesis identifies the needs and opportunities for each of the new player and also develops a cost model for streaming video using this solution.by Amit Limaye.S.M

Toward practical and private online services

Today's common online services (social networks, media streaming, messaging, email, etc.) bring convenience. However, these services are susceptible to privacy leaks. Certainly, email snooping by rogue employees, email server hacks, and accidental disclosures of user ratings for movies are some sources of private information leakage. This dissertation investigates the following question: Can we build systems that (a) provide strong privacy guarantees to the users, (b) are consistent with existing commercial and policy regimes, and (c) are affordable? Satisfying all three requirements simultaneously is challenging, as providing strong privacy guarantees usually necessitates either sacrificing functionality, incurring high resource costs, or both. Indeed, there are powerful cryptographic protocols---private information retrieval (PIR), and secure two-party computation (2PC)---that provide strong guarantees but are orders of magnitude more expensive than their non-private counterparts. This dissertation takes these protocols as a starting point and then substantially reduces their costs by tailoring them using application-specific properties. It presents two systems, Popcorn and Pretzel, built on this design ethos. Popcorn is a Netflix-like media delivery system, that provably hides, even from the content distributor (for example, Netflix), which movie a user is watching. Popcorn tailors PIR protocols to the media domain. It amortizes the server-side overhead of PIR by batching requests from the large number of concurrent users retrieving content at any given time; and, it forms large batches without introducing playback delays by leveraging the properties of media streaming. Popcorn is consistent with the prevailing commercial regime (copyrights, etc.), and its per-request dollar cost is 3.87 times that of a non-private system. The other system described in this dissertation, Pretzel, is an email system that encrypts emails end-to-end between senders and intended recipients, but allows the email service provider to perform content-based spam filtering and targeted advertising. Pretzel refines a 2PC protocol. It reduces the resource consumption of the protocol by replacing the underlying encryption scheme with a more efficient one, applying a packing technique to conserve invocations of the encryption algorithm, and pruning the inputs to the protocol. Pretzel's costs, versus a legacy non-private implementation, are estimated to be up to 5.4 times for the email provider, with additional but modest client-side requirements. Popcorn and Pretzel have fundamental connections. For instance, the cryptographic protocols in both systems securely compute vector-matrix products. However, we observe that differences in the vector and matrix dimensions lead to different system designs. Ultimately, both systems represent a potentially appealing compromise: sacrifice some functionality to build in strong privacy properties at affordable costs.Computer Science

Towards a scalable video interactivity solution over the IMS

Includes bibliographical references (leaves 72-76).Rapid increase in bandwidth and the interactive and scalability features of the Internet provide a precedent for a converged platform that will support interactive television. Next Generation Network platforms such as the IP Multimedia Subsystem (IMS) support Quality of Service (QoS), fair charging and possible integration with other services for the deployment of IPTV services. IMS architecture supports the use of the Session Initiation Protocol (SIP) for session control and the Real Time Streaming Protocol (RTSP) for media control. This study aims to investigate video interactivity designs over the Internet using an evaluation framework to examine the performance of both SIP and RTSP protocols over the IMS over different access networks. It proposes a Three Layered Video Interactivity Framework (TLVIF) to reduce the video processing load on a server

Development of advanced multimedia services in P2P architectures

La transmissió de fluxos multimèdia en temps real (streaming) s’ha convertit en un tema punter i de gran interès al món de la recerca d’Internet, especialment quan ens referim a aplicacions de transmissió d’àudio i vídeo en directe a través de xarxes peer-to-peer (P2P). Generalment, aquestes aplicacions han de fer front a molts problemes en el seu disseny i implementació deguts a la dinamicitat i heterogeneïtat que per natura caracteritzen les xarxes P2P. En aquest projecte, s’introdueixen noves característiques que les aplicacions de transmissió multimèdia P2P actuals no contemplen. Els requisits de connexió i maquinari són diferents per a la transmissió de fluxos de baixa i alta capacitat, no obstant, tots els nodes s’acostumen a considerar idèntics, cosa que no representa una aproximació gaire encertada tenint en compte un medi tan heterogeni. A més a més, amb la finalitat d’aconseguir distinció entre nodes, es fa necessari la introducció d’un mecanisme que permeti l’intercanvi de les capacitats específiques de cada node, incloent-hi les de transcodificació de fluxos. Un altre aspecte a destacar és el fet que aquestes aplicacions són difícils d’ampliar, incorporar nous serveis o modificar les dades que porten precarregades com ara la llista de canals de televisió disponibles, cosa que impossibilita garantir la disponibilitat de la font tot el temps. Per altra banda, els serveis interactius tampoc s’han desenvolupat gaire. Aquest projecte proposa el disseny i implementació d’una plataforma de difusió multimèdia P2P cooperativa i interactiva que permet superar els problemes esmentats. La plataforma integra diferents mecanismes que permeten la distribució en temps real de continguts multimèdia en diferents qualitats incloent fluxos d’alta capacitat (com per exemple HD). Aquesta plataforma és una solució novedosa basada en JXTA, DONET i ALM (Arbres Multicast a nivell d’Aplicació) que proporciona un sistema ampliable segons noves necessitats i facilita la inserció de nous serveis de valor afegit. La plataforma proposada es fonamenta en la creació d’una arquitectura de 2 capes lògiques superposades: una capa lògica JXTA, encarregada bàsicament de la senyalització i intercanvi de metadades, i una capa de transmissió basada en sockets UDP unicast. D’aquesta manera, la diferència entre la capa de transmissió i la capa física es pot veure reduïda a partir de la informació obtinguda de la capa JXTA, la qual es va actualitzant al llarg del temps