<p>Sammanfattning: Det är minst lika många människor som besöker arrangemang och gudstjänster i kyrkor som besöker idrottsevenemang. Det behövs studiogudstjänster dock sänds det allt färre Tv-gudstjänster direkt från kyrkor och medlen för att göra detta är också på väg att minskas. Många som ser dessa gudstjänster har av olika orsaker inte möjlighet att besöka en kyrka. Detta kan t ex bero på funktionshinder och sjukdom men också att många äldre har svårt att förflytta sig och se gudstjänster live. Ett sätt för kyrkorna att nå ut på bredare front skulle kunna vara att använda sig av Internet som media.</p><p>Syftet med uppsatsen är att genom intervjuer, användningstestning och slutligen prototyptestning, ta fram en lösning för digital överföring av ljud och bild från ett ställe till ett annat via ett IP-nätverk och finna en avvägning mellan det tekniska och användbarheten då användaren har begränsad teknisk kunskap.</p><p>Vid datainsamlingen användes en kvalitativ forskningsprocess med intervjuer och observation som insamlingstekniker. Vid användningstesterna användes observation som metod och testpersonerna uppmanades att tänka högt. Analysen av testerna visade vikten av att minimera inblandning av för mycket teknik i lösningarna då områdeskunskapen hos användare varierar kraftigt.</p>

<p>The purpose of this report was to study how the Swedish radio channel Sveriges Radio (SR) website changed over time. What are the differences between various media websites? How many people listen to normal and web-radio and what are the differences between the various services offered on the SR website?</p><p>Reports from the BBC, Statistics Sweden, Mediavision and the Swedish National Post and Telecom Agency were compared. Several theoreticians have been studied, including Donald A Norman, Jonas Löwgren, Karen Holtzbratt, Jacob Nielsen and Geoffrey Moore.</p><p>The method used by the author comprised a systematic mapping of statistics from webTrends, KiaIndex, SiteCensus, TNS Gallup/K2analys and reports from RUAB. The data studied have been collected from telephone interviews, postal surveys, internet panels, and from log files. The statistics have then been compared and in some cases tables have been cross-correlated.</p><p>The results from the various studies showed that SR is following the rising trend displayed by a few of the media websites reviewed. It is of particular interest to note that web-radio listening between the final period 2004 and 2005 almost doubled.</p><p>The next stage will be to offer the listener/user a more central position. By listening to users, and above all non-users, the function and content can be adapted to the larger group of pragmatists and conservative listeners that are looking for sustainable and convenient solutions.</p><p>Key words [Streaming, on demand, radio, analogue, web-radio]</p> / <p>Avsikten med den här rapporten var att ta reda på hur Sveriges Radios (SR) sajt förändras över tid. Vilka skillnader finns det mellan olika mediesajter. Hur många lyssnar på vanlig- kontra webbradio samt vad finns det för skillnader mellan olika tjänster på SR:s sajt.</p><p>Jämförelser har gjorts mellan BBC, SCB, Mediavision samt Post & Telestyrelsens rapporter. Flera teoretiker har studerats som Donald A Norman, Jonas Löwgren, Karen Holtzbratt, Jacob Nielsen och Geoffrey Moore.</p><p>Författarens metod bestod av att systematiskt kartlägga statistik från webTrends, KiaIndex, SiteCensus, TNS Gallup/K2analys samt RUAB:s rapporter. De data som undersökts kommer från telefonintervjuer, postenkäter, Internetpaneler samt loggfiler. Statistiken har jämförts med varandra samt i vissa fall har tabellerna korskörts.</p><p>Resultaten från de olika undersökningarna visar att SR följer den uppåtgående trend som några av de undersökta mediesajterna har. Men det mer intressanta är att webbradiolyssningen mellan sista perioden 2004 och 2005 nästan fördubblats.</p><p>Nästa steg blir att se till att lyssnarna/användarna står mer i centrum. Genom att lyssna på användare, men framför allt icke-användare så skulle funktion och innehåll kunna anpassas till den större gruppen pragmatiker och konservativa som vill ha hållbara och bekväma lösningar.</p>

Peer-to-peer streaming has emerged as a killer application in today's Internet, delivering a large variety of live multimedia content to millions of users at any given time with low server cost. Though successfully deployed, the efficiency and optimality of the current peer-to-peer streaming protocols are still less than satisfactory. In this thesis, we investigate optimizing solutions to enhance the performance of the state-of-the-art mesh-based peer-to-peer streaming systems, utilizing both theoretical performance modeling and extensive real-world measurements. First, we model peer-to-peer streaming applications in both the single-overlay and multi-overlay scenarios, based on the solid foundation of optimization and game theories. Using these models, we design efficient and fully decentralized solutions to achieve performance optimization in peer-to-peer streaming. Then, based on a large volume of live measurements from a commercial large-scale peer-to-peer streaming application, we extensively study the real-world performance of peer-to-peer streaming over a long period of time. Highlights of our measurement study include the topological characterization of large-scale streaming meshes, the statistical characterization of inter-peer bandwidth availability, and the investigation of server capacity utilization in peer-to-peer streaming. Utilizing in-depth insights from our measurements, we design practical algorithms that advance the performance of key protocols in peer-to-peer live streaming. We show that our optimizing solutions fulfill their design objectives in various realistic scenarios, using extensive simulations and experiments.

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.

Accessibility is important in the development of digital products as well as in physical products. An accessible product enables all people to use it, whether they have a disability or not. This thesis focuses on accessibility for visually impaired people in a music streaming service on desktop. Many music streaming services for desktop are built with web technologies, including Spotify. The aim of this thesis was to evaluate the accessibility status of the Spo- tify desktop application as well as develop accessibility guidelines fo- cused on a music streaming service. A user test was performed to in- vestigate the accessibility status of the desktop application. Existing accessibility guidelines was studied and used together with the results of the user test to develop accessibility guidelines applicable to a music streaming service. It was found that the Spotify desktop application had many accessibility issues and these were considered when developing accessibility guide- lines. The existing guidelines studied was the WCAG 2.0 guidelines developed by W3C. These were read through completely and compiled in Chapter 4 of this report. The result of the thesis was accessibility guidelines suitable for a music streaming service on desktop. Since music streaming applications can be developed using different techniques and frameworks these guide- lines should be used as a guide on how to implement accessibility and needs to be customized for each use case. Though the fundamentals of the guidelines should be applicable to most music streaming desktop applications.

M.Ing. / Application Layer Forward Error Correction (AL-FEC) is a relatively new concept which uses erasure codes to add reliability insurance to particular application streams on a network. This concept has become particularly popular for media streaming services. Fountain codes have shown promise as the erasure code of choice for these implementations. The Fountain code concept is a principle that has two popular instantiations, the Luby Transform (LT) code and the Raptor code. While the Raptor code is the more efficient of the two, the LT code is the focal point of our dissertation. Our main objective in this dissertation was broken up into two different primary objectives which we had to satisfy in its completion. The first of these primary objectives entailed the finding of sets of input parameters which would yield an optimal implementation of the LT code for a given set of input block sizes. The simulation work performed in this investigation was done on a wide range of input parameters for each input block size concerned. While there have been a number of other studies which have performed such parameter optimisation we have not found any that present such comprehensive results as we do. The second of the primary objectives related to the analysis of the code when applied as an AL-FEC reliability mechanism for streaming media. This simulation work was performed on simulated IP network environments using the NS2 network simulator. The codes which were applied to the network were based on the optimal parameter sets found in the first objective. We analysed the effective throughput achievable by the code in the face of various packet loss rates. With the data obtained from the simulations we then derived a constraint on the allowable bit-rate of media which uses the LT code as an AL-FEC reliability mechanism. In performing the work in this dissertation it was identified that it was required to develop the LT code related simulation tools for performing the respective investigations. This involved development of a stand-alone LT code simulator as well as an LT code AL-FEC reliability mechanism for NS2.

The usage of smartphones has been increasing with surprising speed. These smartphones are popular for delivery of video content. The main drawbacks of these smartphones are battery life and video freezing. Despite, while streaming a video it consumes large of amount of power affecting QoE. So, in this case we considered streaming a video from server to mobile client involving ONOFF characteristics. While streaming, there exists some transition delay while switching the power states and the effect of these transition delays might affect instantaneous power consumption of the smartphone. Henceforth, this thesis aims to determine the effect on instantaneous power consumption from distributed state durations and transitions in exponential fluid flow model, for a streamed video. Power measurements along with ON and OFF times were measured with the help of a benchmark tool, Monsoon Power Monitor tool. VLQoE tool, a video streaming tool was used to present a two state model based on the inter-picture time, for the HTTP-based video streaming. Experiments were executed in a closed enclosure setup using a black-box to avoid external obstacles that might possibly affect the power consumption metrics. Considering these measurements, the effect on instantaneous power consumption stemming from the exponentially distributed state durations and transitions in the corresponding fluid flow model can be determined and modelled.

With the increase in demand for video streaming services on the hand held mobile terminals with limited battery life, it is important to maintain the user Quality of Experience (QoE) while taking the resource consumption into consideration. Hence, the goal is to offer as good quality as feasible, avoiding as much user-annoyance as possible. Hence, it is essential to deliver the video, avoiding any uncontrollable quality distortions. This can be possible when an optimal (or desirable) throughput value is chosen such that exceeding the particular threshold results in entering a region of unstable QoE, which is not feasible. Hence, the concept of QoE-aware sustainable throughput is introduced as the maximal value of the desirable throughput that avoids disturbances in the Quality of Experience (QoE) due to delivery issues, or keeps them at an acceptable minimum. The thesis aims at measuring the sustainable throughput values when video streams of different resolutions are streamed from the server to a mobile client over wireless links, in the presence of network disturbances packet loss and delay. The video streams are collected at the client side for quality assessment and the maximal throughput at which the QoE problems can still be kept at a desired level is determined. Scatter plots were generated for the individual opinion scores and their corresponding throughput values for the disturbance case and regression analysis is performed to find the best fit for the observed data. Logarithmic, exponential, linear and power regressions were considered in this thesis. The R-squared values are calculated for each regression model and the model with R-squared value closest to 1 is determined to be the best fit. Power regression model and logarithmic model have the R-squared values closest to 1.  Better quality ratings have been observed for the low resolution videos in the presence of packet loss and delay for the considered test cases. It can be observed that the QoE disturbances can be kept at a desirable level for the low resolution videos and from the test cases considered for the investigation, 360px video is more resilient in case of high delay and packet loss values and has better opinion score values. Hence, it can be observed that the throughput is sustainable at this threshold.

Approved for public release; distribution is unlimited / The next step in the evolution of services provided on an intranet or the internet will be distributed or distance learning with collaboration among peers. Currently, this is done on a one-to-one basis. To expand to a one-tomany collaboration environment, there needs to be a server distributing the multimedia content without creating additional network traffic even though many users are accessing or viewing the multimedia content. Multicasting allows many users to view multimedia content without creating additional network traffic. There is a server providing multimedia content to a multicast address so users may access it. This thesis defines metrics and conducts a comparison of different servers capable of distributing multimedia content using the multicasting protocol. / Lieutenant, United States Navy

Advances in hardware, software and communication networks have enabled applications to generate data at unprecedented volume and velocity. An important type of this data are event streams generated from financial transactions, health sensors, web logs, social media, mobile devices, and vehicles. The world is thus poised for a sea-change in time-critical applications from financial fraud detection to health care analytics empowered by inferring insights from event streams in real time. Event processing systems continuously evaluate massive workloads of Kleene queries to detect and aggregate event trends of interest. Examples of these trends include check kites in financial fraud detection, irregular heartbeat in health care analytics, and vehicle trajectories in traffic control. These trends can be of any length. Worst yet, their number may grow exponentially in the number of events. State-of-the-art systems do not offer practical solutions for trend analytics and thus suffer from long delays and high memory costs. In this dissertation, we propose the following event trend detection and aggregation techniques. First, we solve the trade-off between CPU processing time and memory usage while computing event trends over high-rate event streams. Namely, our event trend detection approach guarantees minimal CPU processing time given limited memory. Second, we compute online event trend aggregation at multiple granularity levels from fine (per matched event), to medium (per event type), to coarse (per pattern). Thus, we minimize the number of aggregates – reducing both time and space complexity compared to the state-of-the-art approaches. Third, we share intermediate aggregates among multiple event sequence queries while avoiding the expensive construction of matched event sequences. In several comprehensive experimental studies, we demonstrate the superiority of the proposed strategies over the state-of-the-art techniques with respect to latency, throughput, and memory costs.