In this thesis, the effect of buffer strategy on video quality has been investigated. For this purpose, a software system was developed to implement buffer strategy at sender and receiver sides. Four experiments were performed under this system and five scenarios were designed under each experiment. A subjective test of MOS was conducted for all the scenarios to collect people’s perception about three different videos. People from different background and of different age group were invited to take part in all the experiments. Three different videos were shown to each participant in order to investigate user perceived quality of video. MATLAB and MS Excel were used for data collection and plotting graphs. We conclude that people have convergence of opinions when communication break time increases than the size of buffers at both ends. Finally, the MOS ratings of this subjective test prove that by the use of same size buffers at both ends improves the user’s perceived quality of video at acceptable level. Because of empirical study, the main focus was on implementation strategy of buffers at both ends. The implementation strategy was the design of a number of scenarios in which the statistics of the behavior of sender and receiver buffers have been collected. / 0092 662 424477

In the Internet of today there is a demand for both high bandwidth and low delays. Bandwidth-heavy applications such as large downloads or video streaming compete with more delay-sensitive applications; web-browsing, VoIP and video games. These applications represent a growing share of Internet traffic. Buffers are an essential part of network equipment. They prevent packet loss and help maintain hight throughput. As bandwidths have increased so have the buffer sizes. In some cases way to much. This, and the fact that Active Queue Management (AQM) is seldom implemented, has given rise to a phenomenon called Bufferbloat. Bufferbloat is manifested at the bottleneck of the network path by large flows creating standing queues that choke out smaller, and usually delay-sensitive, flows. Since the bottleneck is often located at the consumer edge, this is where the focus of this thesis lies. This work evaluates three different AQM solutions that lower delays without requiring complicated configuration; CoDel, FQ_CoDel and PIE. FQ_CoDel had the best performance in the tests, with the lowest consistent delays and high throughput. This thesis recommends that AQM is implemented at the network edge, preferably FQ_CoDel.

HTTP Adaptive Streaming (HAS) has now become ubiquitous, and it accounts for a large proportion of multimedia delivery over the Internet. Consequently, it poses new challenges for content providers and network operators. In this study, we aim to improve the user’s Quality of Experience (QoE) for HAS using from two main approaches including client centric approach and network assisted approach. In the client centric approach, we address the issue of enhancing the client’s QoE by proposing a fuzzy logic–based video bitrate adaptation and prediction mechanism for Dynamic Adaptive Streaming over HTTP (DASH) players. This adaptation mechanism allows HAS players to take appropriate actions sooner than existing methods to prevent playback interruptions caused by buffer underrun and reduce the ON-OFF traffic phenomena, which causes instability and unfairness among competing players. Our results show that compared to other studied methods, our proposed method has two advantages: better fairness among multiple competing players by almost 50% on average and as much as 80% as indicated by Jain’s fairness index, and better perceived quality of video by almost 8% on average and as much as 17%, according to the eMOS model. In the network assisted approach, we propose a novel mechanism for HAS stream adaptation in the context of wireless mobile networks. The proposed mechanism leverages recent advances in the 3GPP DASH specification, including the optional feature of QoE measurement and reporting for DASH clients. As part of the proposed mechanism, we formulate a utility-maximization problem that incorporates factors influencing QoE to specify the optimum value of Quality of Service (QoS)-related parameters for HAS streams within a wireless mobile network. The results of our simulations demonstrate that our proposed system results in better perceived quality of video, measured by Mean Opinion Score (MOS), by almost 7% on average, while lowering the freezing period by almost 20% on average across HAS users when compared to other approaches where HAS users only rely on local adaptation logics.

Mobile operators face a scenario characterised by new challenges such as growing data consumption, a slowdown in subscriber growth and reduced revenues due to the success of OTT providers. To remain competitive, mobile operators must offer affordable services and think on strategies to retain current customers. Quality of Experience (QoE) is a well-established methodology for measuring and understanding the overall level of customer satisfaction with a service and has been presented as a way to improve telecommunication services. Even though QoE can be used to solve problems such as customer loyalty and optimisation of network resources in mobile networks, there is a great lack of knowledge on how mobile operators can take advantage of QoE and its potential benefits. This thesis explores the incorporation of QoE in mobile networks to improve their service offering from a technical, regulatory and business perspective.The technical level focuses on the definition of the mechanism to integrate QoE in the operation of mobile networks. The second part of this study has been focused on the regulatory framework on Net Neutrality. Finally,the third part of this thesis focuses on the identification of potential business scenarios and models based on the incorporation of QoE in mobile networks. An important conclusion is that due to the nature of the challenges faced by the mobile industry, a QoE analysis cannot be limited to a technical discussion. A technical solution can be the first step to the first step to overcoming industry challenges. However, it is important that a technical decision comes along with an informed analysis of the regulatory conditions and the business implications of the proposed solution. On the other hand, mobile operators require new methods that integrate technical, market and business considerations to improve their service offer. A method analysed in this dissertation is a Customer Experience Management (CEM) platform. Given the technical, regulatory and business factors covered in this thesis, a CEM platform can be used by mobile operators to make a better use of QoE in their business operation. / Mobiloperatörer möter ett scenario som kännetecknas av en ökande trend inom dataförbrukning, tecken på en avmattning i abonnenttillväxten, en en minskning av de traditionella intäkter på grund av framgången med OTT leverantörer. Dessutom, mobila användare har gott om alternativ för att ändra tjänsteleverantören. I det här fallet måste mobiloperatörer förbli konkurrenskraftiga baseras både på pris och deras abonnenter tillfredsställelse. Kvalitet Erfarenhets (QoE) införlivande i mobilnät kan vara ett av alternativen för att möta vissa mobilbranschen utmaningar som omfattar tekniska, kommersiella och marknadsnivå. QoE möjliggör en bredare och mer övergripande förståelse av användarnas erfarenheter med utförandet av applikationer, tjänster och nätverk, samtidigt som kompletterar traditionella techno-centric begrepp som Quality of Service(QoS). Händelse om användningen av QoE data har föreslagits som ettsätt att lösa problem som optimering av nätverksresurser och kundomsättning upplevs av mobiloperatörer, finns det fortfarande en lucka på hur man utnyttjar QoE och dess potentiella fördelar i ramen för mobilnät. Således är den övergripande inriktningen av denna avhandling på att analysera hur mobiloperatörer kan integrera QoE feedback för att förbättra sin serviceerbjudande.Men på grund av arten av de utmaningar som den mobila industrin står inför, denna analys kan inte begränsas till en teknisk nivå diskussion. även hitta en teknisk lösning skulle kunna vara det första steget för att övervinna utmaningarna på marknaden, är det viktigt att ett tekniskt beslut kommer tillsammans med en välgrundad analys av de regulatoriska förutsättningarna för att genomförandet och affärs konsekvenserna av den föreslagna lösningen.Så kan en skådespelare intresserad av genomförandet av det föreslagna i dennaavhandling mekanism har fler verktyg för ett välgrundat beslut fattandet. På teknisk nivå, fokuserar denna uppsats på identifiering av teknisk mekanismför att införliva QoE i mobilnätet. Sedan vår analys kretsar kring identifieringen av regelverket om nätneutralitet och dess potentiella inverkan på genomförandet av den föreslagna mekanismen för införliva QoE i mobilnät. Slutligen, och letar efter en helhetssyn på QoE frågan, erbjuder vi en analys av konsekvenserna av att införliva QoE för hela mobilnät ekosystemet och intressenterna längs hela värdenätverket. / <p>QC 20161229</p> / Quality of Experience: A Techno-economic Analysis / Quality of Experience and Net Neutrality

Performance Testing is one of the crucial parts of any software cycle process. In today’s world, there is any number of network-based applications. Manual Testing and Automated Testing are the two important ways to test any type of application. For Manual Testing a mobile application known as BlekingeTrafiken is used. For Automated Testing, a web application known as Edmodo is used. Selenium is the automated tool included for automated testing. But, for each application, there are several users and because of that, there might be a decrease in performance of the application as an increase in the number of users. Performance of an application also depends on response times, mean, stability, speed, capacity, accuracy. The performance also depends on the device (memory consumption, battery, software variation) and Server/API (less no of calls) and depends on the network performance (jitters, packet loss, network speed). There are several tools for performance testing. By using these tools, we can get accurate performance results of each request.  In this thesis, we performed manual testing of a mobile application by increasing the number of users under similar network conditions, automated testing of a web application under various test cases and tested the performance of an iPad application (PLANETJAKTEN). It is a real-time gaming application used to learn mathematics for children. Apache JMeter is the tool used for performance testing. The interaction between the JMeter tool and the iPad is done through HTTP Proxy method. When any user starts using the application, we can measure the performance of each request sent by the user. Nagios is the tool used to monitor the various environments. Results show that for manual testing, the time taken for connecting to WI-FI is low compared to opening and using the application. For automated testing, it is found that the time taken to run each test case for the first time is high compared to the remaining trials. For performance testing, the experimental results show that the error percentage (the percentage of failed requests) is high for logging into the application compared to using the application.

This work deals with user satisfaction with mobile data service. The main part is devoted to the development of a mobile application that provides testing network parameters to evaluate and use online databases shared with other users. Discussed the possibility of distributing applications among users over its testing and then to the App Store.

Real time video streaming through mobile Internet is increasing day by day and the video  quality can be affected  very badly by network performance issues. Video freezing and video  jumping are one of the serious issues that affect the user experience badly. Hence service providers are interested to evaluate the performance of quality of experience. We  follow the methods from the International Telecommunications Union–Telecommunication Sector(ITU-T)recommendations. In this thesis, we are studying the effect of freezing on user experience by subjective tests and obtaining the mean opinion scores using perceptual video quality assessment tool and analyze  which part of the video is affected mostly by introducing freezein selected parts.

With the development of mobile web services, it is important to know for a service provider how Quality of Service (QoS) is related with the Quality of Experience (QoE) for the mobile users. Any change in the QoS could be reflected on the QoE. However, good QoS does not always provide good QoE. Thus, a proper combination of QoS and QoE results in a good user experience. Good understanding of QoS and QoE is necessary in order to achieve that. In addition, identifying the proper relationship between network level QoS and user-end QoE is extremely challenging task which requires the highest level of accuracy. In order to understand the relation between QoS and QoE in a web service, an Apache server was setup with Google Map Web Service. In the server side, QoS parameters- delay, jitter and service unavailability were introduced for an experiment. In the user end, QoE was examined by doing experiment with different mobiles. In this test, 18 different conditions were experienced by the user who marked their QoE. This experiment was designed to collect data from the user to examine the user QoE and network level QoS. The results show that without server end Apache QoS module the service might be unavailable in high delay and jitter. However, with the Apache QoS module the service is available in high delay and jitter even though it takes longer time to respond. For better QoE, the delay and jitter should be as low as possible. Moreover, better QoE is experienced in better mobile design. Good mobile receiver and resolution make the QoE higher. Lower quality mobile design cannot ensure good service even though the network level QoS is good.

Computer games, especially Massively Multiplayer Online Role Playing Games, have elements where communication between players is of great need. This communication is generally conducted through in-game text chats, in-game voice chats or external voice programs. In-game voice chats can be constructed to work in a similar way as talking does in real life. When someone talks, anyone close enough to that person can hear what is said, with a volume depending on distance. This is called positional or spatial voice chat in games. This differs from the commonly implemented voice chat where participants in conversations are statically defined by a team or group belonging. Positional voice chat has been around for quite some time in games and it seems to be of interest for a lot of users, despite this, it is still not very common. This thesis investigates impacts of implementing a positional voice chat in the existing MMORPG Mortal Online by Star Vault. How is it built, what are the costs, how many users can it support and what do the users think of it? These are some of the questions answered within this project. The design science research method has been selected as scientific method. A product in form of a positional voice chat library has been constructed. This library has been integrated into the existing game engine and its usage has been evaluated by the game’s end users. Results show a positional voice system that in theory supports up to 12500 simultaneous users can be built from scratch and be patched into an existing game in less than 600 man-hours. The system needs third-party libraries for threading, audio input/output, audio compression, network communication and mathematics. All libraries used in the project are free for use in commercial products and do not demand code using them become open source. Based on a survey taken by more than 200 users, the product received good ratings on Quality of Experience and most users think having a positional voice chat in a game like Mortal Online is important. Results show a trend of young and less experienced users giving the highest average ratings on quality, usefulness and importance of the positional voice chat, suggesting it may be a good tool to attract new players to a game.

In software engineering it is important to consider how a potential user experiences the system during usage. No software user will have a satisfying experience if they perceive the system as slow, unresponsive, unstable or hiding information. Additionally, if the system restricts the users to only having a limited set of actions, their experience will further degrade. In order to evaluate the effect these issues have on a user‟s perceived experience, a measure called Quality of Experience is applied. In this work the foremost objective was to improve how a user experienced a system suffering from the previously mentioned issues, when searching for large amounts of data. To achieve this objective the system was evaluated to identify the issues present and which issues were affecting the user perceived Quality of Experience the most. The evaluated system was a warehouse management system developed and maintained by Aptean AB‟s office in Hässleholm, Sweden. The system consisted of multiple clients and a server, sending data over a network. Evaluation of the system was in form of a case study analyzing its performance, together with a survey performed by Aptean staff to gain knowledge of how the system was experienced when searching for large amounts of data. From the results, three issues impacting Quality of Experience the most were identified: (1) interaction; limited set of actions during a search, (2) transparency; limited representation of search progress and received data, (3) execution time; search completion taking long time. After the system was analyzed, hypothesized technological solutions were implemented to resolve the identified issues. The first solution divided the data into multiple partitions, the second decreased data size sent over the network by applying compression and the third was a combination of the two technologies. Following the implementations, a final set of measurements together with the same survey was performed to compare the solutions based on their performance and improvement gained in perceived Quality of Experience. The most significant improvement in perceived Quality of Experience was achieved by the data partitioning solution. While the combination of solutions offered a slight further improvement, it was primarily thanks to data partitioning, making that technology a more suitable solution for the identified issues compared to compression which only slightly improved perceived Quality of Experience. When the data was partitioned, updates were sent more frequently and allowed the user not only a larger set of actions during a search but also improved the information available in the client regarding search progress and received data. While data partitioning did not improve the execution time it offered the user a first set of data quickly, not forcing the user to idly wait, making the user experience the system as fast. The results indicated that to increase the user‟s perceived Quality of Experience for systems with server-client communication, data partitioning offered several opportunities for improvement. / I programvaruteknik är det viktigt att överväga hur en potentiell användare upplever ett system vid användning. Ingen användare kommer att ha en tillfredsställande upplevelse om de uppfattar systemet som långsamt, icke responsivt, ostabilt eller döljande av information. Dessutom, om systemet binder användarna till ett begränsat antal möjliga handlingar, kommer deras upplevelse vidare försämras. För att utvärdera vilken påverkan dessa problem har på en användares upplevda kvalitet, används mätenheten Upplevd Tjänstekvalitet. I detta arbete var det huvudsakliga syftet att förbättra en användares upplevelse av ett system som led av de tidigare nämnda problemen vid sökning av större datamängder. För att uppnå detta syfte utvärderades systemet för att identifiera befintliga problem samt vilka som mest påverkade användares Upplevda Tjänstekvalitet. Systemet som utvärderades var en mjukvara för lagerhantering som utvecklades och underhölls av Aptean AB‟s kontor i Hässleholm, Sverige. Systemet bestod av flera klienter och en server som skickade data över ett nätverk. Systemet utvärderades med en fallstudie där prestandan anayserades tillsammans med en enkät utförd i samarbete med Apteans personal för att få insikt i hur systemet upplevdes vid sökningar av stora datamängder. Resultaten visade på tre problem som hade störst inverkan på den Upplevda Tjänstekvaliteten: (1) interaktion; begränsade antal möjliga handlingar under en sökning, (2) transparens; begränsad tillgång till information om sökningens progress samt den hämtade datan, (3) körningstid; slutförande av en sökning tog lång tid. Efter att systemet hade analyserats, implementerades hypotetiska teknologiska lösningar för att lösa de identifierade problemen. Den första lösningen delade in datan i ett flertal partitioner, den andra minskade datans storlek som skickades över nätverket genom att tillämpa komprimering och den tredje var en kombination av de två teknologierna. Efter implementationen utfördes en sista uppsättning mätningar tillsammans med enkäten för att jämföra lösningarna baserat på deras prestanda och förbättringar av Upplevd Tjänstekvalitet. Den mest signifikanta förbättringen av Upplevd Tjänstekvalitet kom från datapartitioneringslösningen. Trots att kombinationen av lösningar uppnådde en mindre vidare förbättring, var det primärt tack vare datapartitioneringen, vilket innebar att den teknologin var den mest passande lösningen till de identifierade problemen jämfört med komprimering, vilken visade på endast en liten förbättring av Upplevd Tjänstekvalitet. När data partitionerades kunde flera uppdateringar skickas och användaren tilläts ett större antal möjliga handlingar under en sökning, men också en förbättrad tillgång till information i klienten angående sökningens progress samt den hämtade datan. Trots att datapartitionering inte förbättrade körningstiden, kunde den erbjuda användaren en första mängd data snabbt utan att tvinga användaren att sysslolöst vänta, vilket gjorde att systemet upplevdes som snabbt. För att förbättra den Upplevda Tjänstekvaliteten för system med server-klient kommunikation visade resultaten att datapartitionering är en lösning som erbjöd flera möjligheter för förbättring.