Cost-Efficient Storage for On-Demand Video Streaming on Cloud

Video stream is converted to several formats to support the user's device, this conversion process is called video transcoding, which imposes high storage and powerful resources. With emerging of cloud technology, video stream companies adopted to process video on the cloud. Generally, many formats of the same video are made (pre-transcoded) and streamed to the adequate user's device. However, pre-transcoding demands huge storage space and incurs a high-cost to the video stream companies. More importantly, the pre-transcoding of video streams could be hierarchy carried out through different storage types in the cloud. To minimize the storage cost, in this paper, we propose a method to store video streams in the hierarchical storage of the cloud. Particularly, we develop a method to decide which video stream should be pre-transcoded in its suitable cloud storage to minimize the overall cost. Experimental simulation and results show the effectiveness of our approach, specifically, when the percentage of frequently accessed videos is high in repositories, the proposed approach minimizes the overall cost by up to 40 percent.Comment: International IEEE World Forum for Internet of Thing

Architecture and Protocol to Optimize Videoconference in Wireless Networks

[EN] In the past years, videoconferencing (VC) has become an essential means of communications. VC allows people to communicate face to face regardless of their location, and it can be used for different purposes such as business meetings, medical assistance, commercial meetings, and military operations. There are a lot of factors in real-time video transmission that can affect to the quality of service (QoS) and the quality of experience (QoE). The application that is used (Adobe Connect, Cisco Webex, and Skype), the internet connection, or the network used for the communication can affect to the QoE. Users want communication to be as good as possible in terms of QoE. In this paper, we propose an architecture for videoconferencing that provides better quality of experience than other existing applications such as Adobe Connect, Cisco Webex, and Skype. We will test how these three applications work in terms of bandwidth, packets per second, and delay using WiFi and 3G/4G connections. Finally, these applications are compared to our prototype in the same scenarios as they were tested, and also in an SDN, in order to improve the advantages of the prototype.This work has been supported by the "Ministerio de Economia y Competitividad" in the "Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia, Subprograma Estatal de Generacion de Conocimiento" within the project under Grant TIN2017-84802-C2-1-P.Jimenez, JM.; García-Navas, JL.; Lloret, J.; Romero Martínez, JO. (2020). Architecture and Protocol to Optimize Videoconference in Wireless Networks. Wireless Communications and Mobile Computing. 2020:1-22. https://doi.org/10.1155/2020/4903420S122202

Une approche flexible et décentralisée du traitement de requêtes dans les systèmes géo-distribués

This thesis studies the design of query processing systems, across a diversity of geo-distributed settings. Optimising performance metrics such as response time, freshness, or operational cost involves design decisions, such as what derived state (e.g., indexes, materialised views, or caches) to maintain, and how to distribute and where to place the corresponding computation and state. These metrics are often in tension, and the trade-offs depend on the specific application and/or environment. This requires the ability to adapt the query engine's topology and architecture, and the placement of its components. This thesis makes the following contributions: - A flexible architecture for geo-distributed query engines, based on components connected in a bidirectional acyclic graph. - A common microservice abstraction and API for these components, the Query Processing Unit (QPU). A QPU encapsulates some primitive query processing task. Multiple QPU types exist, which can be instantiated and composed into complex graphs. - A model for constructing modular query engine architectures as a distributed topology of QPUs, enabling flexible design and trade-offs between performance metrics. - Proteus, a QPU-based framework for constructing and deploying query engines. - Representative deployments of Proteus and experimental evaluation thereof.Cette thèse présente l'étude de la conception de systèmes de traitement de requêtes dans divers cadres géo-distribués. L'optimisation des mesures de performance telles que le temps de réponse, la fraîcheur ou le coût opérationnel implique des décisions de conception tel que le choix de l’état dérivé (indices, vues matérialisées, caches par ex.) à construire et maintenir, et la distribution et le placement de ces derniers et de leurs calculs. Ces métriques sont souvent opposées et les compromis dépendent de l'application et/ou de la spécificité de l'environnement. La capacité d'adapter la topologie et l'architecture du système de traitement de requêtes devient alors essentielle, ainsi que le placement de ses composants. Cette thèse apporte les contributions suivantes : - Une architecture flexible pour les systèmes de traitement de requêtes géo-distribués, basée sur des composants connectés dans un graphe bidirectionnel acyclique. - Une abstraction de micro-service et une API communes pour ces composants, le Query Processing Unit (QPU). Un QPU encapsule une tâche de traitement de requête primitive. Il existe plusieurs types de QPU qui peuvent être instanciés et composés en graphes complexes. - Un modèle pour construire des architectures de systèmes de traitement de requêtes modulaires composées d’une topologie distribuée de QPUs, permettant une conception flexible et des compromis selon les mesures de performance visées. - Proteus, un framework basé sur les QPU, permettant la construction et le déploiement de systèmes de traitement de requêtes. - Déploiements représentatifs de systèmes de traitement de requêtes à l'aide de Proteus, et leur évaluation expérimentale

Effective and Economical Content Delivery and Storage Strategies for Cloud Systems

Cloud computing has proved to be an effective infrastructure to host various applications and provide reliable and stable services. Content delivery and storage are two main services provided by the cloud. A high-performance cloud can reduce the cost of both cloud providers and customers, while providing high application performance to cloud clients. Thus, the performance of such cloud-based services is closely related to three issues. First, when delivering contents from the cloud to users or transferring contents between cloud datacenters, it is important to reduce the payment costs and transmission time. Second, when transferring contents between cloud datacenters, it is important to reduce the payment costs to the internet service providers (ISPs). Third, when storing contents in the datacenters, it is crucial to reduce the file read latency and power consumption of the datacenters. In this dissertation, we study how to effectively deliver and store contents on the cloud, with a focus on cloud gaming and video streaming services. In particular, we aim to address three problems. i) Cost-efficient cloud computing system to support thin-client Massively Multiplayer Online Game (MMOG): how to achieve high Quality of Service (QoS) in cloud gaming and reduce the cloud bandwidth consumption; ii) Cost-efficient inter-datacenter video scheduling: how to reduce the bandwidth payment cost by fully utilizing link bandwidth when cloud providers transfer videos between datacenters; iii) Energy-efficient adaptive file replication: how to adapt to time-varying file popularities to achieve a good tradeoff between data availability and efficiency, as well as reduce the power consumption of the datacenters. In this dissertation, we propose methods to solve each of aforementioned challenges on the cloud. As a result, we build a cloud system that has a cost-efficient system to support cloud clients, an inter-datacenter video scheduling algorithm for video transmission on the cloud and an adaptive file replication algorithm for cloud storage system. As a result, the cloud system not only benefits the cloud providers in reducing the cloud cost, but also benefits the cloud customers in reducing their payment cost and improving high cloud application performance (i.e., user experience). Finally, we conducted extensive experiments on many testbeds, including PeerSim, PlanetLab, EC2 and a real-world cluster, which demonstrate the efficiency and effectiveness of our proposed methods. In our future work, we will further study how to further improve user experience in receiving contents and reduce the cost due to content transfer

Code renewability for native software protection

Software protection aims at safeguarding assets embedded in software by preventing and delaying reverse engineering and tampering attacks. This article presents an architecture and supporting tool flow to renew parts of native applications dynamically. Renewed and diversified code and data belonging to either the original application or to linked-in protections are delivered from a secure server to a client on demand. This results in frequent changes to the software components when they are under attack, thus making attacks harder. By supporting various forms of diversification and renewability, novel protection combinations become available and existing combinations become stronger. The prototype implementation is evaluated on several industrial use cases

Code Renewability for Native Software Protection

Software protection aims at safeguarding assets embedded in software by preventing and delaying reverse engineering and tampering attacks. This paper presents an architecture and supporting tool flow to renew parts of native applications dynamically. Renewed and diversified code and data belonging to either the original application or to linked-in protections are delivered from a secure server to a client on demand. This results in frequent changes to the software components when they are under attack, thus making attacks harder. By supporting various forms of diversification and renewability, novel protection combinations become available, and existing combinations become stronger. The prototype implementation is evaluated on a number of industrial use cases

Development of industrial IoT based monitoring and control system for radio broadcasting network in Tanzania: a case of Tanzania broadcasting corporation

A Final Project Report Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in Embedded and Mobile System of the Nelson Mandela African Institution of Science and TechnologyThe radio towers must be constructed in sharp elevations or mountains to ensure the maximum radio wave propagation and long-distance coverage of the radio station programs. Due to the sharp elevation positioning of radio towers, the tower operators or technicians are required to climb up every day to be able to take readings of the equipment. Strenuous and daily effort is needed to access these sharp locations either on foot or by car. A need to develop and implement a system that will monitor and send earlier notifications information on the status of the transmitter to the responsible tower operators. Therefore, this project aims to develop an IIoT based monitoring and control system for terrestrial broadcasting networks with outdated technology of Fm transmitter equipment which isstill used in Tanzania. As a result, the solution will effectively and timely assist tower operators to monitor, collecting information understanding and the existing problems that are happening at the radio towers without physically climbing to the radio towers. In addition, the system is cost-effective and collect information in real-time based as it is integrated with a mobile application in a smart device that is linked to the embedded system which is installed in a specific tower to monitor parameters such as forward power, reflected power, electrical units, fuel level, temperature, humidity, and smoke. This study has used a mixed-design approach of quantitative and qualitative methods using focus group discussions with 20 stakeholders to evaluate the developed system. The result of the evaluation shows that 90% of the respondents agreed that the developed system is robust and appropriate to manage the existing challenges at the radio towers.The radio towers must be constructed in sharp elevations or mountains to ensure the maximum radio wave propagation and long-distance coverage of the radio station programs. Due to the sharp elevation positioning of radio towers, the tower operators or technicians are required to climb up every day to be able to take readings of the equipment. Strenuous and daily effort is needed to access these sharp locations either on foot or by car. A need to develop and implement a system that will monitor and send earlier notifications information on the status of the transmitter to the responsible tower operators. Therefore, this project aims to develop an IIoT based monitoring and control system for terrestrial broadcasting networks with outdated technology of Fm transmitter equipment which isstill used in Tanzania. As a result, the solution will effectively and timely assist tower operators to monitor, collecting information understanding and the existing problems that are happening at the radio towers without physically climbing to the radio towers. In addition, the system is cost-effective and collect information in real-time based as it is integrated with a mobile application in a smart device that is linked to the embedded system which is installed in a specific tower to monitor parameters such as forward power, reflected power, electrical units, fuel level, temperature, humidity, and smoke. This study has used a mixed-design approach of quantitative and qualitative methods using focus group discussions with 20 stakeholders to evaluate the developed system. The result of the evaluation shows that 90% of the respondents agreed that the developed system is robust and appropriate to manage the existing challenges at the radio towers