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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Smart-Fit: Peer-to-Peer Topology Construction Strategy for Live Video Streaming towards Minimized Delay

Chang, Chun-hao 18 July 2009 (has links)
Due to the fast growing bandwidth of Internet users, the P2P video streaming on the Internet becomes one of impaortant solutions to release the traffic load. However, the current studies fall short of addressing the video delay issue on live P2P streaming. In this research, we proposed a topology construction method: Smart-Fit, towards minimizing the transmission delay between users and video server. The concept is based on minimizing the hop counts between server and users, in further to reduce the delay. With the bandwidth variety of Internet users, the proppsed method builds a predicted ideal template. Then the users¡¦ joining and leaving behaviors and the system¡¦s topology are constructed according to the template. Simulation results show the proposed method successfully reduces the hop count and the transmission delay between users and server. Moreover, due to the reduction of hop count, the packet loss rate is also reduced.
42

Implementations of Multiple Tunnels for MPEG-4 Stream Splitting on Wireless LANs

Hsu, Yang-Shun 10 September 2009 (has links)
Traditional Mobile IP supports only one tunnel between HA (Home Agent) and FA (Foreign Agent) for MN (Mobile Node) to transmit data from CN (Corresponding Node) to MN during handoff. To alleviate traffic load, in this Thesis, we propose a multiple-tunnel approach by setting up a secondary tunnel in addition to the primary tunnel. HA can split the video stream from the primary tunnel to the secondary tunnel when the former encounters high traffic load. Thus, quality of video stream from CN to MN can be guaranteed through the proposed multiple-tunnel schemes. For the purpose of validation, we implement the multiple-tunnel schemes on Linux platform for HA, FA, and MN to support video stream splitting. Specifically, if HA detects that high system load occurs on FA, an MPEG-4 packet filter is activated on HA to split some portions of video packets from the primary tunnel to the secondary tunnel based on I/B/P frame types. Video receiver on MN can then successfully recover these two divided video packets and playback the complete stream smoothly. Three experiments for validation are developed. They are (i) a simple Mobile IP handoff, (ii) Different bit rates to activate the stream splitting mechanism, and (iii) automatic adjustment of stream splitting according to system load. The experimental results have proved that the proposed multiple-tunnel schemes can substantially improve the quality of video streams.
43

Atsiunčiamų transliacijos įrašų panaudojimas televizijos laidų reklamai / Video announcement`s broadcasting ways

Pocius, Vytautas 11 August 2009 (has links)
Šiame baigiamajame darbe atlikta analizė, kurioje gilinamasi į podcast`ingo privalumus ir pranašumus ir galimybes, lyginant su video transliavimu, dar kitaip vadinamu video „streaming“. Taip pat gilinamasi į tai, kokius pranašumus televizija turėtų prieš kitas, kurios nenaudoja podcast technologijos laidų anonsavimui žiūrovams. Ieškoma alternatyvių projektų, kuriuose bandoma padaryti kažką panašaus. Aprašant projektinius sprendimus, supažindinama su:  būsimu prototipu  televizijos reklamos sprendimas panaudojant podcast technologiją  terminalo tipo atpažinimas  atsiunčiamų transliacijos įrašų panaudojimas televizijos laidų reklamai pritaikymas pagal terminalo tipą  alternatyviu atsiunčiamų transliacijos įrašų panaudojimu televizijos laidų reklamai mobiliajame telefone Atlikus praktinius tyrimus, įsitikinome, kad padarytas prototipas veikia. Tiesa, turi šiokių tokiu trūkumų, kurie dar galėtu būti tobulinami ateityje. / This master `s work analystes advantage of podcasting versus video broadcasting, in other words – video streaming, video podcast expectation of using it. Also I will look through what advantage has Tv stations against these who don`t use podcast technology. Also, there will be looking for some similar podcast projects too. Solutions will be presented:  prototipe  advertisements of tv`s shows  identification of terminal  video announcement`s broadcasting using any type of terminal  video announcement`s broadcasting using mobile phones  alternative video announcement`s broadcasting on mobile phones. In conclusion we can see prototipe is working. In thruth it is not everything working perfect and it should be developed near in future.
44

Quality-Driven Cross-Layer Protocols for Video Streaming over Vehicular Ad-Hoc Networks

Asefi, Mahdi 30 August 2011 (has links)
The emerging vehicular ad-hoc networks (VANETs) offer a variety of applications and new potential markets related to safety, convenience and entertainment, however, they suffer from a number of challenges not shared so deeply by other types of existing networks, particularly, in terms of mobility of nodes, and end-to-end quality of service (QoS) provision. Although several existing works in the literature have attempted to provide efficient protocols at different layers targeted mostly for safety applications, there remain many barriers to be overcome in order to constrain the widespread use of such networks for non-safety applications, specifically, for video streaming: 1) impact of high speed mobility of nodes on end-to-end QoS provision; 2) cross-layer protocol design while keeping low computational complexity; 3) considering customer-oriented QoS metrics in the design of protocols; and 4) maintaining seamless single-hop and multi-hop connection between the destination vehicle and the road side unit (RSU) while network is moving. This thesis addresses each of the above limitations in design of cross-layer protocols for video streaming application. 1) An adaptive MAC retransmission limit selection scheme is proposed to improve the performance of IEEE 802.11p standard MAC protocol for video streaming applications over VANETs. A multi-objective optimization framework, which jointly minimizes the probability of playback freezes and start-up delay of the streamed video at the destination vehicle by tuning the MAC retransmission limit with respect to channel statistics as well as packet transmission rate, is applied at road side unit (RSU). Two-hop transmission is applied in zones in which the destination vehicle is not within the transmission range of any RSU. In the multi-hop scenario, we discuss the computation of access probability used in the MAC adaptation scheme and propose a cross-layer path selection scheme; 2) We take advantage of similarity between multi-hop urban VANETs in dense traffic conditions and mesh connected networks. First, we investigate an application-centric routing scheme for video streaming over mesh connected overlays. Next, we introduce the challenges of urban VANETs compared to mesh networks and extend the proposed scheme in mesh network into a protocol for urban VANETs. A classification-based method is proposed to select an optimal path for video streaming over multi-hop mesh networks. The novelty is to translate the path selection over multi-hop networks to a standard classification problem. The classification is based on minimizing average video packet distortion at the receiving nodes. The classifiers are trained offline using a vast collection of video sequences and wireless channel conditions in order to yield optimal performance during real time path selection. Our method substantially reduces the complexity of conventional exhaustive optimization methods and results in high quality (low distortion). Next, we propose an application-centric routing scheme for real-time video transmission over urban multi-hop vehicular ad-hoc network (VANET) scenarios. Queuing based mobility model, spatial traffic distribution and prob- ability of connectivity for sparse and dense VANET scenarios are taken into consideration in designing the routing protocol. Numerical results demonstrate the gain achieved by the proposed routing scheme versus geographic greedy forwarding in terms of video frame distortion and streaming start-up delay in several urban communication scenarios for various vehicle entrance rate and traffic densities; and 3) finally, the proposed quality-driven routing scheme for delivering video streams is combined with a novel IP management scheme. The routing scheme aims to optimize the visual quality of the transmitted video frames by minimizing the distortion, the start-up delay, and the frequency of the streaming freezes. As the destination vehicle is in motion, it is unrealistic to assume that the vehicle will remain connected to the same access router (AR) for the whole trip. Mobile IP management schemes can benefit from the proposed multi-hop routing protocol in order to adapt proxy mobile IPv6 (PMIPv6) for multi-hop VANET for video streaming applications. The proposed cross-layer protocols can significantly improve the video streaming quality in terms of the number of streaming freezes and start-up delay over VANETs while achieving low computational complexity by using pattern classification methods for optimization.
45

Investigation of Multi-dimensional QoE Models with the Impact of Resolution Vs Stalls for Video Streaming

Nuka, Sravya January 2018 (has links)
In the revolutionary world of Telecommunications industry, costumer’s satisfaction with the product plays a pivotal role. The QoE is affected by the quality of service of a network provided by the service providers. Generic relationship between Quality of Experience and Quality of Service aids to the evolution of smarter ways of regulating the network performance. Accordingly, several studies have engrossed on classifying the relationships between QoE and QoS, seldom noticing the exponential and logarithmic relationships. Correspondingly, investigating the influence of diverse parameters such as stalls, delays, losses on QoE and analyzing whether the additive model or multiplicative model fits the best. In this work, the aim is to investigate the relationships between multi-dimensional QoE space and multi-dimensional QoS parameters. In order to build the subtlety in the sector of multi-dimensional QoE models for multi factor QoS parameters, this study has been conducted.Since the demand for high quality videos is rising tremendously, it has been a necessity for the service and network providers to ensure the best service. In this study a statistical analysis was performed based on quality assessment method. The videos were streamed using the VLC Player and the user’s reactions were logged. A questionnaire was prepared with questions regarding quality and disturbances observed Figure 14. A total of 15 users participated in the study. The data collected in the study was analyzed using averages, correlations and regression analysis. Comparisons were made between the additive modelling approach and multiplicative modelling approach by linear regression. In conclusion, proposing that the multiplicative model is the best fit for resolutions vs stalls w.r.t mean opinion score (MOS).
46

Towards High Quality Video Streaming over Urban Vehicular Networks Using a Location-aware Multipath Scheme

Wang, Renfei January 2012 (has links)
The transmitting of video content over Vehicular Ad Hoc Networks (VANETs) faces a great number of challenges caused by strict QoS (Quality of Service) requirements and highly dynamic network topology. In order to tackle these challenges, multipath forwarding schemes can be regarded as potential solutions. However, route coupling effect and the path length growth severely impair the performance of multipath schemes. In this thesis, the current research status about video streaming over VANETs as well as multipath transmissions are reviewed. With the demand to discover a more suitable solution, we propose the Location-Aware Multipath Video Streaming (LIAITHON+) protocol to address video streaming over urban VANETs. LIAITHON+ uses location information to discover relatively short paths with minimal route coupling effect. The performance results have shown it outperforms the underlying single path solution as well as the node-disjoint multipath solution. In addition, the impact of added redundancy on the multipath solution is investigated through LIAITHON+. According to the results, added redundancy has a different impact depending on the data rate.
47

Mobilní aplikace zpracování obrazu / Mobile Application of Image Processing

Planer, Jan January 2015 (has links)
This thesis addresses video streaming from smartphone to smartwatch. The main goal of the thesis is to find a way how to handle the limited hardware features of the watch and make video streaming as fast and smooth as possible. A part of this work is focused on implementation of client-server application, which streams video from Android device to Tizen smartwatch over Bluetooth channel.
48

Consumer preferences in video streaming

Dolou, Théo, Jacoud, Clara January 2022 (has links)
Social media is the undisputed leader regarding video streaming consumption at an international level, to the detriment of SVOD services. We arrived at this observation trying to understand consumer behaviors regarding this phenomenon. Surprised by this, we sought to understand what motivates consumers to watch streaming video. In the literature, scholars seeking to study the motivations and satisfactions (called gratification factors) of consumers in media use are working with the Uses and Gratification Theory. However, while this theory explains the use of a medium, it does not explain the preference of one medium over another. We therefore wanted to use the Uses and Gratifications framework to make this comparison between social media and SVOD, and thus find an explanation for our observation: the superiority of social media. We drew on previous work to construct gratification factors applicable to SVOD, social media and video streaming. To confirm the reliability and validity of these constructs, we conducted a factorial analysis in a quantitative study, using a questionnaire distributed to the French population. Moreover, we used the data from this survey to build explanatory models for the use of social media and SVOD. Therefore, our study shows that the Uses and Gratifications Theory can be used to explain consumers’ preference for social media over SVOD services, by highlighting that the gratification factors which are the most decisive are content, process and social. Moreover, the formation of our constructs (content, social, process and technology gratifications) is the result of our reorganization of the gratifications already considered in the existing literature so that they correspond most accurately to the current behaviors of streaming video consumers. We thus provide a new basic model of analysis, which could be used by other studies on video streaming. From a practical point of view, our study also allows us to suggest to video streaming companies the points on which they can work to meet consumers’ expectations: that is to say on the possibility for users to adapt their consumption to their available time and on the possibility for interactivity directly on the platforms.
49

eCRM features and customer loyalty : A qualitative study within the video streaming industry

Karphammar, Millie, Brettschneider, Jennifer January 2021 (has links)
The video streaming industry has grown at a rapid speed during the past decade and has becomea trending topic in regard to technological advancements. Nowadays, there are manycompetitors in the market, and it is getting harder to stand out from the competition. Furthermore, the customers are demanding more in their choice of video streaming servicesand are expecting several features and functions in order to retain the service. Electronic Customer Relationship Management (eCRM) is a tool that has been used by providers of videostreaming services in order to improve long-term customer relationships. eCRM has beenresearched before as well as implemented by many companies. However, there are stillresearch gaps in relation to a potential impact that eCRM features have on customer loyalty, aswell as a managerial need to investigate these issues further. The purpose of this thesis is to develop deeper knowledge about how pre-, at- and postpurchase features of eCRM affect the customer loyalty in the video streaming industry. Thecontext of the study was the video streaming industry as it has increased majorly in popularityover the past years and there are many features to consider in the purchasing process. Therefore,we developed a conceptual model that was based on prior research to investigate the influenceof specific features on customer loyalty. The empirical data collection was conductedconsidering the conceptual model. This study was conducted by using a qualitative methodwith semi structured interviews, the respondents consisted of active users of a streaming serviceat the age between 18 to 34 years old. By analyzing the empirical data, we could determinefeatures of eCRM that affected and did not affect customer loyalty in our study. The findings showed that all the steps of the purchase process had features that affectedcustomer loyalty. The features of pre-purchase that we found relevant to customer loyalty inour study were captivating customers, which refers to the ability to attract customers' attention. The features of captivating customers are marketing, popularity, and recommendations, andout of these features, it was popularity and recommendation that we found affecting thecustomers loyalty. The features of the second step in the purchase process, at-purchase, that wefound affecting customer loyalty in our study were assortment, price, and convenience. Assortment refers to the content and supply of the service while the price refers to how muchthe service cost. Convenience is divided into four parts, the number of profiles, active users,devices that can use the service and the ability to stream offline, all these features exceptstreaming offline were found to have an effect on customer loyalty. Post-purchase refers to astage after the purchase has been made and, in our study, we found that the feature of clientcommunication has an effect on customer loyalty. Client communication is the communicationthat accrue between company and customer.
50

Quality Selection for Dynamic Adaptive Streaming over HTTP with Scalable Video Coding

Andelin, Travis L. 07 December 2011 (has links) (PDF)
Video streaming on the Internet is increasingly using Dynamic Adaptive Streaming over HTTP (DASH), in which the video is converted into various quality levels and divided into two-second segments. A client can then adjust its video quality over time by choosing to download the appropriate quality level for a given segment using standard HTTP. Scalable Video Coding (SVC) is a promising enhancement to the DASH protocol. With SVC, segments are divided into subset bitstream blocks. At playback, blocks received for a given segment are combined to additively increase the current quality. Unlike traditional DASH, which downloads segments serially, this encoding creates a large space of possible ways to download a video; for example, if given a variable download rate, when should the client try to maximize the current segment's video quality, and when should it instead play it safe and ensure a minimum level of quality for future segments? In this work, we examine the impact of SVC on the client's quality selection policy, with the goal of maximizing a performance metric quantifying user satisfaction. We use acombination of analysis, dynamic programming, and simulation to show that, in many cases, a client should use a diagonal quality selection policy, balancing both of the aforementioned concerns, and that the slope of the best policy flattens out as the variation in download rateincreases.

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