5,628 research outputs found

    Smart PIN: performance and cost-oriented context-aware personal information network

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    The next generation of networks will involve interconnection of heterogeneous individual networks such as WPAN, WLAN, WMAN and Cellular network, adopting the IP as common infrastructural protocol and providing virtually always-connected network. Furthermore, there are many devices which enable easy acquisition and storage of information as pictures, movies, emails, etc. Therefore, the information overload and divergent content’s characteristics make it difficult for users to handle their data in manual way. Consequently, there is a need for personalised automatic services which would enable data exchange across heterogeneous network and devices. To support these personalised services, user centric approaches for data delivery across the heterogeneous network are also required. In this context, this thesis proposes Smart PIN - a novel performance and cost-oriented context-aware Personal Information Network. Smart PIN's architecture is detailed including its network, service and management components. Within the service component, two novel schemes for efficient delivery of context and content data are proposed: Multimedia Data Replication Scheme (MDRS) and Quality-oriented Algorithm for Multiple-source Multimedia Delivery (QAMMD). MDRS supports efficient data accessibility among distributed devices using data replication which is based on a utility function and a minimum data set. QAMMD employs a buffer underflow avoidance scheme for streaming, which achieves high multimedia quality without content adaptation to network conditions. Simulation models for MDRS and QAMMD were built which are based on various heterogeneous network scenarios. Additionally a multiple-source streaming based on QAMMS was implemented as a prototype and tested in an emulated network environment. Comparative tests show that MDRS and QAMMD perform significantly better than other approaches

    Reliable Video Streaming over mmWave with Multi Connectivity and Network Coding

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    The next generation of multimedia applications will require the telecommunication networks to support a higher bitrate than today, in order to deliver virtual reality and ultra-high quality video content to the users. Most of the video content will be accessed from mobile devices, prompting the provision of very high data rates by next generation (5G) cellular networks. A possible enabler in this regard is communication at mmWave frequencies, given the vast amount of available spectrum that can be allocated to mobile users; however, the harsh propagation environment at such high frequencies makes it hard to provide a reliable service. This paper presents a reliable video streaming architecture for mmWave networks, based on multi connectivity and network coding, and evaluates its performance using a novel combination of the ns-3 mmWave module, real video traces and the network coding library Kodo. The results show that it is indeed possible to reliably stream video over cellular mmWave links, while the combination of multi connectivity and network coding can support high video quality with low latency.Comment: To be presented at the 2018 IEEE International Conference on Computing, Networking and Communications (ICNC), March 2018, Maui, Hawaii, USA (invited paper). 6 pages, 4 figure

    Digital television applications

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    Studying development of interactive services for digital television is a leading edge area of work as there is minimal research or precedent to guide their design. Published research is limited and therefore this thesis aims at establishing a set of computing methods using Java and XML technology for future set-top box interactive services. The main issues include middleware architecture, a Java user interface for digital television, content representation and return channel communications. The middleware architecture used was made up of an Application Manager, Application Programming Interface (API), a Java Virtual Machine, etc., which were arranged in a layered model to ensure the interoperability. The application manager was designed to control the lifecycle of Xlets; manage set-top box resources and remote control keys and to adapt the graphical device environment. The architecture of both application manager and Xlet forms the basic framework for running multiple interactive services simultaneously in future set-top box designs. User interface development is more complex for this type of platform (when compared to that for a desktop computer) as many constraints are set on the look and feel (e.g., TV-like and limited buttons). Various aspects of Java user interfaces were studied and my research in this area focused on creating a remote control event model and lightweight drawing components using the Java Abstract Window Toolkit (AWT) and Java Media Framework (JMF) together with Extensible Markup Language (XML). Applications were designed aimed at studying the data structure and efficiency of the XML language to define interactive content. Content parsing was designed as a lightweight software module based around two parsers (i.e., SAX parsing and DOM parsing). The still content (i.e., text, images, and graphics) and dynamic content (i.e., hyperlinked text, animations, and forms) can then be modeled and processed efficiently. This thesis also studies interactivity methods using Java APIs via a return channel. Various communication models are also discussed that meet the interactivity requirements for different interactive services. They include URL, Socket, Datagram, and SOAP models which applications can choose to use in order to establish a connection with the service or broadcaster in order to transfer data. This thesis is presented in two parts: The first section gives a general summary of the research and acts as a complement to the second section, which contains a series of related publications.reviewe

    Development and standardization of an embedded Linux based triple-play IP settop box

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    Thesis (Master)--Izmir Institute of Technology, Electronics and Communication Engineering, Izmir, 2007Includes bibliographical references (leaves: 46-48)Text in English; Abstract: Turkish and Englishix, 57 leavesWith the recent enhancements to the delivery of IP services and of the video codecs such as h.264, transmission of television through IP-based communication systems has been a viable option. An IP settop box (IPSTB) constructs a bridge between a television set and a broadband IP network such as DSL, cable modem, powerline or wireless broadband. IPSTB brings new challenges for the system designers, especially in the areas of inherently organized home networking systems, protocols, and architectures. Future IPSTB products are candidate to converge the information and entertainment technologies. This thesis suggests newly developed device and service discovery methods for the design of an IPSTB software structure that is compatible with the Universal Plug and Play (UPnP) audio video (AV) device descriptions. At the design process, it suggests optimized communication schemes between the servers that are in the control of service providers, and the consumer IPSTBs. As a newly developed technology, since there is not any standardization for most parts of the overall IPTV system, this thesis takes proven mechanisms as basis and adapts them to the overall design that consists of the hardware drivers, middleware, and the additional programs which helps the middleware to handle the external components of the system connected via USB or serial interfaces. Being an innovative idea, we have used a control system called Virtual Bus Manager so as to communicate between the aforementioned system components. Some system components such as web browser is based on the X Windows architecture, so cross compiling the X system for the embedded platform has also been a challenge for the feasibility of the final design. Being the second part of the Triple-Play system, Voice over IP application has also been included and based on the compilation of open source software for the corresponding embedded system. Finally, the web browser itself has been based on the popular Gecko web-core that is derived from Firefox

    Proxy-based near real-time TV content transmission in mobility over 4G with MPEG-DASH transcoding on the cloud

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    [EN] This paper presents and evaluates a system that provides TV and radio services in mobility using 4G communications. The system has mainly two blocks, one on the cloud and another on the mobile vehicle. On the cloud, a DVB (Digital Video Broadcasting) receiver obtains the TV/radio signal and prepares the contents to be sent through 4G. Specifically, contents are transcoded and packetized using the DASH (Dynamic Adaptive Streaming over HTTP) standard. Vehicles in mobility use their 4G connectivity to receive the flows transmitted by the cloud. The key element of the system is an on-board proxy that manages the received flows and offers them to the final users in the vehicle. The proxy contains a buffer that helps reduce the number of interruptions caused by hand over effects and lack of coverage. The paper presents a comparison between a live transmission using 4G connecting the clients directly with the cloud server and a near real-time transmission based on an on-board proxy. Results prove that the use of the proxy reduces the number of interruptions considerably and, thus, improves the Quality of Experience of users at the expense of slightly increasing the delay.This work is supported by the Centro para el Desarrollo Tecnologico Industrial (CDTI) from the Government of Spain under the project "Plataforma avanzada de conectividad en movilidad" (CDTI IDI-20150126) and the project "Desarrollo de nueva plataforma de entretenimiento multimedia para entornos nauticos" (CDTI TIC-20170102).Arce Vila, P.; De Fez Lava, I.; Belda Ortega, R.; Guerri Cebollada, JC.; Ferrairó, S. (2019). Proxy-based near real-time TV content transmission in mobility over 4G with MPEG-DASH transcoding on the cloud. Multimedia Tools and Applications. 78(18):26399-26425. https://doi.org/10.1007/s11042-019-07840-6S2639926425781

    Architectures and Key Technical Challenges for 5G Systems Incorporating Satellites

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    Satellite Communication systems are a promising solution to extend and complement terrestrial networks in unserved or under-served areas. This aspect is reflected by recent commercial and standardisation endeavours. In particular, 3GPP recently initiated a Study Item for New Radio-based, i.e., 5G, Non-Terrestrial Networks aimed at deploying satellite systems either as a stand-alone solution or as an integration to terrestrial networks in mobile broadband and machine-type communication scenarios. However, typical satellite channel impairments, as large path losses, delays, and Doppler shifts, pose severe challenges to the realisation of a satellite-based NR network. In this paper, based on the architecture options currently being discussed in the standardisation fora, we discuss and assess the impact of the satellite channel characteristics on the physical and Medium Access Control layers, both in terms of transmitted waveforms and procedures for enhanced Mobile BroadBand (eMBB) and NarrowBand-Internet of Things (NB-IoT) applications. The proposed analysis shows that the main technical challenges are related to the PHY/MAC procedures, in particular Random Access (RA), Timing Advance (TA), and Hybrid Automatic Repeat reQuest (HARQ) and, depending on the considered service and architecture, different solutions are proposed.Comment: Submitted to Transactions on Vehicular Technologies, April 201

    Ad-hoc Stream Adaptive Protocol

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    With the growing market of smart-phones, sophisticated applications that do extensive computation are common on mobile platform; and with consumers’ high expectation of technologies to stay connected on the go, academic researchers and industries have been making efforts to find ways to stream multimedia contents to mobile devices. However, the restricted wireless channel bandwidth, unstable nature of wireless channels, and unpredictable nature of mobility, has been the major road block for wireless streaming advance forward. In this paper, various recent studies on mobility and P2P system proposal are explained and analyzed, and propose a new design based on existing P2P systems, aimed to solve the wireless and mobility issues

    Otimização de distribuição de conteúdos multimédia utilizando software-defined networking

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    The general use of Internet access and user equipments, such as smartphones, tablets and personal computers, is creating a new wave of video content consumption. In the past two decades, the Television broadcasting industry went through several evolutions and changes, evolving from analog to digital distribution, standard definition to high definition TV-channels, form the IPTV method of distribution to the latest set of technologies in content distribution, OTT. The IPTV technology introduced features that changed the passive role of the client to an active one, revolutionizing the way users consume TV content. Thus, the clients’ habits started to shape the services offered, leading to an anywhere and anytime offer of video content. OTT video delivery is a reflection of those habits, meeting the users’ desire, introducing several benefits discussed in this work over the previous technologies. However, the OTT type of delivery poses several challenges in terms of scalability and threatens the Telecommunications Operators business model, because OTT companies use the Telcos infrastructure for free. Consequently, Telecommunications Operators must prepare their infrastructure for future demand while offering new services to stay competitive. This dissertation aims to contribute with insights on what infrastructure changes a Telecommunications Operator must perform with a proposed bandwidth forecasting model. The results obtained from the forecast model paved the way to the proposed video content delivery method, which aims to improve users’ perceived Quality-of-Experience while optimizing load balancing decisions. The overall results show an improvement of users’ experience using the proposed method.A generalização do acesso à Internet e equipamentos pessoais como smartphones, tablets e computadores pessoais, está a criar uma nova onda de consumo de conteúdos multimedia. Nas ultimas duas décadas, a indústria de transmissão de Televisão atravessou várias evoluções e alterações, evoluindo da distribuição analógica para a digital, de canais de Televisão de definição padrão para alta definição, do método de distribuição IPTV, até ao último conjunto de tecnologias na distribuição de conteúdos, OTT. A tecnologia IPTV introduziu novas funcionalidades que mudaram o papel passivo do cliente para um papel activo, revolucionando a forma como os utilizadores consumem conteúdos televisivos. Assim, os hábitos dos clientes começaram a moldar os serviços oferecidos, levando à oferta de consumo de conteúdos em qualquer lugar e em qualquer altura. A entrega de vídeo OTT é um reflexo destes hábitos, indo ao encontro dos desejos dos utilizadores, que introduz inúmeras vantagens sobre outras tecnologias discutidas neste trabalho. No entanto, a entrega de conteúdos OTT cria diversos problemas de escalabilidade e ameaça o modelo de negócio das Operadoras de Telecomunicações, porque os fornecedores de serviço OTT usam a infraestrutura das mesmas sem quaisquer custos. Consequentemente, os Operadores de Telecomunicações devem preparar a sua infraestrutura para o consumo futuro ao mesmo tempo que oferecem novos serviços para se manterem competitivos. Esta dissertação visa contribuir com conhecimento sobre quais alterações uma Operadora de Telecomunicações deve executar com o modelo de previsão de largura de banda proposto. Os resultados obtidos abriram caminho para o método de entrega de conteúdos multimedia proposto, que visa ao melhoramento da qualidade de experiência do utilizador ao mesmo tempo que se optimiza o processo de balanceamento de carga. No geral os testes confirmam uma melhoria na qualidade de experiência do utilizador usando o método proposto.Mestrado em Engenharia de Computadores e Telemátic
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