Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / A multimedia system combines audio, video, graphics, and text into one presentation. Each of these multimedia data types has distinct temporal characteristics. For example video has a specific number of frames that must be displayed per second. There are also temporal relationships that exist between the media. In a movie application, the audio and video streams must be synchronized to achieve a lip syncing effect. In our system, we manage these temporal requirements through the scheduling of the communication channel; multimedia data is retrieved across the network at the appropriate time so that temporal presentation requirements are met. This real-time scheduling forms a basis for the limited a priori (LAP) scheduler. The scheduler assumes that it knows enough about the system a priori to schedule the next period or limited portion of the presentation. By considering only one period at a time, the scheduler can adapt to dynamic user input or changing communication channel characteristics. A network delay model and retrieval delay estimation are used by the LAP scheduler when scheduling objects so that they arrive before their playout deadlines. This modeling and estimation also allow the LAP scheduler to decide when there are changes in the communication channel performance that require adjustments to the retrieval schedule. Furthermore, they enable the LAP scheduler to lower the resource requirements of a multimedia presentation when there is less than sufficient network bandwidth or buffer space for normal playout. The characteristics of the LAP scheduler are first described by analyzing the delay estimation techniques. Properties of the LAP scheduler are further investigated by using performance results from an FDDI network simulation and from an implementation of the LAP scheduler between two Unix workstations interconnected by an Ethernet network. The LAP scheduler wss found to satisfy the proposed objectives for multimedia data retrieval. However, its performance is hindered by the difficulty in predicting network traffic patterns, the normal approximations in the estimation process, and the lack of scheduling for resources other than the communication channel. / 2031-01-01

With advances in wireless technology and mobile devices, the number of mobile users using multimedia services has increased significantly in recent years. Mobile devices can be connected and roam on heterogeneous wireless networks. The IEEE 802.21 group has designed a Media Independent Handover (MIH) standard to ensure seamless Vertical Handover (VHO) in heterogeneous networks. However, the standard currently depends on features of the network (e.g. the type of network and available bandwidth) to achieve seamless VHO. This approach is limited, as it does not consider how a Quality of Experience (QoE) can be provided and maintained for customers when delivering multimedia services in heterogeneous wireless networks. The aim of the project is to develop a novel QoE-driven VHO management framework for providing and maintaining an appropriate level of QoE of multimedia services as the mobile user’s actual requirements in heterogeneous wireless networks. A QoE-driven VHO algorithm is more efficient for maintaining this acceptable QoE of multimedia services than traditional network-based or QoS-based VHO algorithms. There are three main contributions during this project. Firstly, A thorough evaluation of the performance of voice and video services via Skype was carried out in terms of the QoE metric (i.e. MOS). This work identified the impact of video content and packet loss on the QoE metric for voice and video communication services over wireless networks. Secondly, a QoE-driven VHO algorithm was developed to provide and maintain an acceptable QoE of mobile video services for mobile users. Compared to a traditional network-based VHO algorithm, this algorithm can provide better QoE and maintain acceptable QoE. Lastly, the User-centric QoE-driven (UCQoE) VHO framework to provide satisfactory QoE of multimedia services according to the mobile user’s requirements. The framework allows users to set their own preferences (e.g. quality-guarantee or cost-free) and carry out VHO operations accordingly. The evaluation showed that the proposed framework can provide a better QoE for delivered video services than QoS-based and network-based VHO algorithms. Furthermore, the proposed framework can be used to avoid unnecessary cost of mobile data when the option of cost-free is preferred by the user. During this project, three international conference papers had been published and a journal paper has been submitted to IEEE Transactions on Mobile Computing. The main contribution-UCQoE VHO management framework can be developed to maintain QoE of all mobile services in the future.

An adaptive resource reservation and handoff priority scheme, which jointly considers the characteristics from the physical, link and network layers, is proposed for a packet switching Multicode (MC)-CDMA cellular network supporting multimedia applications. A call admission region is derived for call admission control (CAC) and handoff management with the satisfaction of quality of service (QoS) requirements for all kinds of multimedia traffic, where the QoS parameters include the wireless transmission bit error rate (BER), the packet loss rate (PLR) and delay requirement. The BER requirement is guaranteed by properly arranging simultaneous packet transmissions, whereas the PLR and delay requirements are guaranteed by the proposed packet scheduling and partial packet integration scheme. To give service priority to handoff calls, a threshold-based adaptive resource reservation scheme is proposed on the basis of a practical user mobility model and a proper handoff request prediction scheme. The resource reservation scheme gives handoff calls a higher admission priority over new calls, and is designed to adjust the reservation-request time threshold adaptively according to the varying traffic load. The individual reservation requests form a common reservation pool, and handoff calls are served on a first-come-first-serve basis. By exploiting the transmission rate adaptability of video calls to the available radio resources, the resources freed from rate-adaptive high-quality video calls by service degradation can be further used to prioritize handoff calls. With the proposed resource reservation and handoff priority scheme, the dynamic properties of the system can be closely captured and a better grade of service (GoS) in terms of new call blocking and handoff call dropping probabilities(rates) can be achieved compared to other schemes in literature. Numerical results are presented to show the improvement of the GoS performance and the efficient utilization of the radio resources.

An adaptive resource reservation and handoff priority scheme, which jointly considers the characteristics from the physical, link and network layers, is proposed for a packet switching Multicode (MC)-CDMA cellular network supporting multimedia applications. A call admission region is derived for call admission control (CAC) and handoff management with the satisfaction of quality of service (QoS) requirements for all kinds of multimedia traffic, where the QoS parameters include the wireless transmission bit error rate (BER), the packet loss rate (PLR) and delay requirement. The BER requirement is guaranteed by properly arranging simultaneous packet transmissions, whereas the PLR and delay requirements are guaranteed by the proposed packet scheduling and partial packet integration scheme. To give service priority to handoff calls, a threshold-based adaptive resource reservation scheme is proposed on the basis of a practical user mobility model and a proper handoff request prediction scheme. The resource reservation scheme gives handoff calls a higher admission priority over new calls, and is designed to adjust the reservation-request time threshold adaptively according to the varying traffic load. The individual reservation requests form a common reservation pool, and handoff calls are served on a first-come-first-serve basis. By exploiting the transmission rate adaptability of video calls to the available radio resources, the resources freed from rate-adaptive high-quality video calls by service degradation can be further used to prioritize handoff calls. With the proposed resource reservation and handoff priority scheme, the dynamic properties of the system can be closely captured and a better grade of service (GoS) in terms of new call blocking and handoff call dropping probabilities(rates) can be achieved compared to other schemes in literature. Numerical results are presented to show the improvement of the GoS performance and the efficient utilization of the radio resources.

The increase mobile data traffic from the emerging Internet services, especially multimedia, has posed considerable challenges for the telecom industry. Their initial mobile data services business models are generally not compatible with these emerging Internet services. Thus, there is a substantial need to investigate the suitable options to make media as a profitable telecom business sector. However, there are different challenges and opportunity factors in developing sustainable mobile media business in each market, due to the unique circumstances applied as the result of customer characteristics, mobile market situation and regulatory/law enforcement.</p><p>The first purpose of this thesis is to explore the business model options to deliver media services on top of mobile broadband. Although, we limit our focus to Indonesia, we first analyzed the worldwide patterns toward the media services in order to get a broader view of the current trend. We mapped multitudes of actor involved in digital online / on the top (OTT)media service, which together they form different types of constellation in the value network,as well as service, delivery and revenue model. We also put our focus to get the lessons learned from Spotify's business model, by framing it using Chesbrough and Rosenbloom's model.</p><p>The second purpose is to understand the Indonesian mobile user's characteristic toward the mobile media services. We conducted survey to 119 Indonesians, analyzed the result with one sample T-tests and validated it with the correlation tests (Cronbach Alpha and Pearson correlation), within the Unified theory of acceptance and use of technology (UTAUT)framework. Our findings confirm the low willingness to pay, but an open attitude for the services. The mobile device and network quality are not the barriers for them to adopt the services, and there is a tight connection between the decisions to adopt the services with the perception that the service is popular.</p><p>Through those findings, we assessed the feasibility of the identified options and formulated the recommendations. We used our understanding about Indonesian market structure (telecom and media), regulation, and mobile user, as well as the lesson that we got from media services provisioning in Sweden and worldwide trend. We found that the pricing tiers, adjustable pricing, and differentiated features are some of the key success factors.Meanwhile, being part in the point-to-multipoint partnership with the well-known OTT player is the potential position that the Mobile network operators (MNOs) in Indonesia should take in provisioning OTT media services, rather than deliver the services by their own.

Aujourd'hui, la satisfaction du client et la joie deviennent les principaux différenciateurs pour évaluer l'efficacité des opérateurs télécoms et les fournisseurs de services. Dans ce marché concurrentiel, la mauvaise qualité de l'expérience (QoE) conduit à une réaction en chaîne de la parole négative de la bouche, pousser les clients dans les bras de concurrents en attente. Par conséquent, il est important pour les fournisseurs de services pour assurer la qualité supérieure de l'expérience afin d'éviter la déloyauté clientèle et la réputation négative. QoE est une émergence rapide multi-disciplinaire discipline axée sur la compréhension globale des exigences de qualité de l'homme sous différents angles tels que la technologie, des affaires et contexte d'utilisation. Le premier défi et avant tout est de comprendre comment différentes caractéristiques qui influencent liés à l'activité, la technologie, et le comportement influence du contexte humain. Dans cette thèse, les premiers travaux répond à ce défi de comprendre l'influence des domaines disparates sur QoE. Un modèle d'interaction QoE consolidée est proposé qui relie les domaines disparates (humains, des affaires, la technologie, et le contexte) pour comprendre la qualité globale de l'homme de l'expérience requise. Puis la taxonomie est présenté pour le modèle d'interaction QoE. Deuxième contribution dans cette thèse est basé sur le premier et son principal objectif est de capturer et analyser des données QoE à travers des études de l'utilisateur. Sur la base de données de l'utilisateur, l'influence des paramètres technologiques, contextuelles et d'affaires de plus de QoE sont évalués. Différents services multimédias ont été sélectionnés pour l'étude d'utilisateur tels que le service de streaming vidéo, la téléphonie (VoIP et PSTN), et service de téléconférence audio 3D. Selon le service multimédia, différents aspects ont été considérés lors de chaque étude sur les utilisateurs telles que les types de paramètres de service (QoS multimédia, le contenu, le contexte), les types de mesures (QoE subjective, objectif cognitif ou les deux), les caractéristiques de l'homme (âge, sexe, etc) , et les rôles de l'homme (l'utilisateur ou le client). Ces résultats aident à comprendre le lien entre QoE et d'autres domaines d'influence. La troisième contribution est basée sur les travaux en cours d'élaboration QoE des outils basés sur des services de streaming vidéo. Deux outils basés sur QoE pour l'évaluation des services multimédias ont été présentés dans cette thèse, leurs principales fonctions consistent à saisir, analyser et rapporter métriques QoE en temps réel. Ces outils sont utiles pour QoE mesure en temps réel de paramètres QoE / Today, the fulfillment of customer demands and user experience requirements are becoming the main differentiators for gauging the effectiveness of telecom operators and service providers. In this competitive market, the poor Quality of Experience (QoE) leads to a chain reaction of negative word of mouth, pushing customers into the arms of waiting competitors. Therefore it is important for service providers to ensure superior quality of experience in order to avoid customer disloyalty and negative reputation. QoE is a fast emerging multi-disciplinary field focused on understanding overall human quality requirements from different angles such as technology, business and context of use. The first and foremost challenge is to understand how different influencing characteristics related to business, technology, and context influence human behavior. In this thesis, initial work addresses this challenge of understanding the influence of disparate domains over QoE. A consolidated QoE interaction model is proposed which links disparate domains (human, business, technology, and context) to understand overall human quality of experience requirements. Then taxonomy is presented for QoE interaction model. Second contribution in this thesis is based on the first and its main objective is to capture and analyze QoE data through user studies. Based on user data, the influence of technological, contextual and business parameters over QoE are evaluated. Different multimedia services were selected for user study such as video streaming service, telephony (VoIP and PSTN), and 3D audio teleconferencing service. Depending upon multimedia service, different aspects were considered during each user study such as types of multimedia service parameters (QoS, content, context), the types of QoE metrics (subjective, objective cognitive or both), human characteristics (age, gender etc), and human roles (user, or customer). These findings help in understanding the link between QoE and other influencing domains. The third contribution is based upon ongoing work of developing QoE based tools for video streaming services. Two QoE based tools for the assessment of multimedia services have been presented in this thesis, their main functions are to capture, analyze and report QoE metrics in real time. These QoE tools are useful for real time measurement of QoE metrics

Since the coronavirus pandemic in 2019, millions of people started to use online streaming and entertainment services during the lockdown. Streaming solutions such as OTT and IPTV has grown and boosted the live streaming and non-linear streaming revenue, by using new technologies and innovation such as Artificial Intelligence (AI) to improve the video quality, performance, and security of video streaming services. However, QoS and QoE guarantee and traffic management is still a challenge to many multimedia services and systems provided over the Internet. In this paper the analysis of a proposed user-friendly design will be discussed, describing how it can improve the management and troubleshooting experience. And in what way an AI knowledge-based agent can be used to improve and support the operators daily tasks and challenges. With an usability test, the results showed that the combination of an user-centered interface and AI-technology can improve the productivity in video troubleshooting and prevention of common issues. The user-centered design focuses on the user’s goal and needs, using interactive products to help the user achieve their goal. And the AI would assist the operators to identifying network congestion, stream quality, and much more.

Today, the fulfillment of customer demands and user experience requirements are becoming the main differentiators for gauging the effectiveness of telecom operators and service providers. In this competitive market, the poor Quality of Experience (QoE) leads to a chain reaction of negative word of mouth, pushing customers into the arms of waiting competitors. Therefore it is important for service providers to ensure superior quality of experience in order to avoid customer disloyalty and negative reputation. QoE is a fast emerging multi-disciplinary field focused on understanding overall human quality requirements from different angles such as technology, business and context of use. The first and foremost challenge is to understand how different influencing characteristics related to business, technology, and context influence human behavior. In this thesis, initial work addresses this challenge of understanding the influence of disparate domains over QoE. A consolidated QoE interaction model is proposed which links disparate domains (human, business, technology, and context) to understand overall human quality of experience requirements. Then taxonomy is presented for QoE interaction model. Second contribution in this thesis is based on the first and its main objective is to capture and analyze QoE data through user studies. Based on user data, the influence of technological, contextual and business parameters over QoE are evaluated. Different multimedia services were selected for user study such as video streaming service, telephony (VoIP and PSTN), and 3D audio teleconferencing service. Depending upon multimedia service, different aspects were considered during each user study such as types of multimedia service parameters (QoS, content, context), the types of QoE metrics (subjective, objective cognitive or both), human characteristics (age, gender etc), and human roles (user, or customer). These findings help in understanding the link between QoE and other influencing domains. The third contribution is based upon ongoing work of developing QoE based tools for video streaming services. Two QoE based tools for the assessment of multimedia services have been presented in this thesis, their main functions are to capture, analyze and report QoE metrics in real time. These QoE tools are useful for real time measurement of QoE metrics

The master’s thesis describes IMS (IP Multimedia Subsystem) in terms of IMS core ele- ments (functional description, different implementation, signaling etc.) Communication protocols SIP and DIAMETER, together with SNMP protocol, which is used for collecting data are briefly described in this thesis.Thesis is also describing various IMS projects to- gether with Open IMS project, for whom was this surveillance system designed. Next part deals with architecture design of surveillance system along with management options implemented in surveillance system for users and administrators. The main part of master’s thesis deals with the description of the surveillance system for the experimental school Open IMS network and describes the remote configuration of core elements and monitoring of network traffic, together with the monitoring servers performance. The most of the data in the designed surveillance system are processed into graphs, which are regularly updated. The final part of master’s thesis describes the configuration and implementation of monitoring tools MRTG and NfSen that were used in created web based surveillance system.

L'émergence et la croissance rapide des services multimédia dans les réseaux IP ont créé de nouveaux défis pour les fournisseurs de services réseau, qui, au-delà de la Qualité de Service (QoS) issue des paramètres techniques de leur réseau, doivent aussi garantir la meilleure qualité de perception utilisateur (Quality of Experience, QoE) dans des réseaux variés avec différentes technologies d'accès. Habituellement, différentes méthodes et techniques sont utilisées pour prédire le niveau de satisfaction de l'utilisateur, en analysant l'effet combiné de multiples facteurs. Dans cette thèse, nous nous intéressons à la commande du réseau en intégrant à la fois des aspects qualitatifs (perception du niveau de satisfaction de l'usager) et quantitatifs (mesure de paramètres réseau) dans l'objectif de développer des mécanismes capables, à la fois, de s'adapter à la variabilité des mesures collectées et d'améliorer la qualité de perception. Pour ce faire, nous avons étudié le cas de deux services multimédia populaires, qui sont : le streaming vidéo, et la voix sur IP (VoIP). Nous investiguons la QoE utilisateur de ces services selon trois aspects : (1) les méthodologies d'évaluation subjective de la QoE, dans le cadre d'un service vidéo, (2) les techniques d'adaptation de flux vidéo pour garantir un certain niveau de QoE, et (3) les méthodes d'allocation de ressource, tenant compte de la QoE tout en économisant l'énergie, dans le cadre d'un service de VoIP (LTE-A). Nous présentons d'abord deux méthodes pour récolter des jeux de données relatifs à la QoE. Nous utilisons ensuite ces jeux de données (issus des campagnes d'évaluation subjective que nous avons menées) pour comprendre l'influence de différents paramètres (réseau, terminal, profil utilisateur) sur la perception d'un utilisateur d'un service vidéo. Nous proposons ensuite un algorithme de streaming vidéo adaptatif, implémenté dans un client HTTP, et dont le but est d'assurer un certain niveau de QoE et le comparons à l'état de l'art. Notre algorithme tient compte de trois paramètres de QoS (bande passante, taille de mémoires tampons de réception et taux de pertes de paquets) et sélectionne dynamiquement la qualité vidéo appropriée en fonction des conditions du réseau et des propriétés du terminal de l'utilisateur. Enfin, nous proposons QEPEM (QoE Power Efficient Method), un algorithme d'ordonnancement basé sur la QoE, dans le cadre d'un réseau sans fil LTE, en nous intéressant à une allocation dynamique des ressources radio en tenant compte de la consommation énergétique / The emerging and fast growth of multimedia services have created new challenges for network service providers in order to guarantee the best user's Quality of Experience (QoE) in diverse networks with distinctive access technologies. Usually, various methods and techniques are used to predict the user satisfaction level by studying the combined impact of numerous factors. In this thesis, we consider two important multimedia services to evaluate the user perception, which are: video streaming service, and VoIP. This study investigates user's QoE that follows three directions: (1) methodologies for subjective QoE assessment of video services, (2) regulating user's QoE using video a rate adaptive algorithm, and (3) QoE-based power efficient resource allocation methods for Long Term Evaluation-Advanced (LTE-A) for VoIP. Initially, we describe two subjective methods to collect the dataset for assessing the user's QoE. The subjectively collected dataset is used to investigate the influence of different parameters (e.g. QoS, video types, user profile, etc.) on user satisfaction while using the video services. Later, we propose a client-based HTTP rate adaptive video streaming algorithm over TCP protocol to regulate the user's QoE. The proposed method considers three Quality of Service (QoS) parameters that govern the user perception, which are: Bandwidth, Buffer, and dropped Frame rate (BBF). The BBF method dynamically selects the suitable video quality according to network conditions and user's device properties. Lastly, we propose a QoE driven downlink scheduling method, i.e. QoE Power Escient Method (QEPEM) for LTE-A. It esciently allocates the radio resources, and optimizes the use of User Equipment (UE) power utilizing the Discontinuous Reception (DRX) method in LTE-A