658 research outputs found

    On Content-centric Wireless Delivery Networks

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    The flux of social media and the convenience of mobile connectivity has created a mobile data phenomenon that is expected to overwhelm the mobile cellular networks in the foreseeable future. Despite the advent of 4G/LTE, the growth rate of wireless data has far exceeded the capacity increase of the mobile networks. A fundamentally new design paradigm is required to tackle the ever-growing wireless data challenge. In this article, we investigate the problem of massive content delivery over wireless networks and present a systematic view on content-centric network design and its underlying challenges. Towards this end, we first review some of the recent advancements in Information Centric Networking (ICN) which provides the basis on how media contents can be labeled, distributed, and placed across the networks. We then formulate the content delivery task into a content rate maximization problem over a share wireless channel, which, contrasting the conventional wisdom that attempts to increase the bit-rate of a unicast system, maximizes the content delivery capability with a fixed amount of wireless resources. This conceptually simple change enables us to exploit the "content diversity" and the "network diversity" by leveraging the abundant computation sources (through application-layer encoding, pushing and caching, etc.) within the existing wireless networks. A network architecture that enables wireless network crowdsourcing for content delivery is then described, followed by an exemplary campus wireless network that encompasses the above concepts.Comment: 20 pages, 7 figures,accepted by IEEE Wireless Communications,Sept.201

    Understanding Timelines within MPEG Standards

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    (c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Nowadays, media content can be delivered via diverse broadband and broadcast technologies. Although these different technologies have somehow become rivals, their coordinated usage and convergence, by leveraging of their strengths and complementary characteristics, can bring many benefits to both operators and customers. For example, broadcast TV content can be augmented by on-demand broadband media content to provide enriched and personalized services, such as multi-view TV, audio language selection, and inclusion of real-time web feeds. A piece of evidence is the recent Hybrid Broadcast Broadband TV (HbbTV) standard, which aims at harmonizing the delivery and consumption of (hybrid) broadcast and broadband TV content. A key challenge in these emerging scenarios is the synchronization between the involved media streams, which can be originated by the same or different sources, and delivered via the same or different technologies. To enable synchronized (hybrid) media delivery services, some mechanisms providing timelines at the source side are necessary to accurately time align the involved media streams at the receiver-side. This paper provides a comprehensive review of how clock references (timing) and timestamps (time) are conveyed and interpreted when using the most widespread delivery technologies, such as DVB, RTP/RTCP and MPEG standards (e.g., MPEG-2, MPEG-4, MPEG-DASH, and MMT). It is particularly focused on the format, resolution, frequency, and the position within the bitstream of the fields conveying timing information, as well as on the involved components and packetization aspects. Finally, it provides a survey of proofs of concepts making use of these synchronization related mechanisms. This complete and thorough source of information can be very useful for scholars and practitioners interested in media services with synchronization demands.This work has been funded, partially, by the "Fondo Europeo de Desarrollo Regional" (FEDER) and the Spanish Ministry of Economy and Competitiveness, under its R&D&i Support Program in project with ref TEC2013-45492-R.Yuste, LB.; Boronat Segui, F.; Montagut Climent, MA.; Melvin, H. (2015). Understanding Timelines within MPEG Standards. Communications Surveys and Tutorials, IEEE Communications Society. 18(1):368-400. https://doi.org/10.1109/COMST.2015.2488483S36840018

    Flexible HW-SW design and analysis of an MMT-based MANET system on FPGA

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    Recently there has been a rapid growth of research interests in Mobile Ad-hoc Networks (MANETs). Their infrastructureless and dynamic nature demands that new strategies be implemented on a robust wireless communication platform in order to provide efficient end-to-end communication. Many routing algorithms have been developed to serve this purpose. This thesis investigated Multi-Meshed Tree (MMT) algorithm, an integrated solution that combines routing, clustering and medium access control operations based on a common multi-meshed tree concept. It provides the robustness and redundancy inherent in mesh topologies and uses the tree branches to deliver packets. MMT is the first of its kind that enables a single algorithm to form multiple proactive routes within a cluster while supporting reactive routes between different clusters. Recent published research and simulations have shown its favorable features and results. To explore the MMT algorithm\u27s novel feature in real systems against simulation work, this work adopts Field Programmable Gate Arrays (FPGA) as the platform for wireless system implementations. Full hardware and various System-on-Chip Hardware-Software designs are developed and studied, providing a design practice that contributes to low-cost system development in the field of MANET by utilizing the evolving FPGA technology. The results show that the MMT-based systems functioned accurately and effectively; in all proposed test scenarios they demonstrated many of the features that a desired MANET routing algorithm should have: high transmission success rate, low latency, scalability, few queued packets and low overhead. The results give valuable insights into the MMT algorithm\u27s performance and facilitate its future improvements

    USE OF MULTIMEDIA TECHNOLOGY AMONG THE LECTURER AND STUDENTS OF OSUN STATE UNIVERSITY

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    The aim of this study is to investigate the use of multimedia technology by lecturers and undergraduate students in Osun State University. The study was guided by four research questions. The study adopted descriptive survey design sample was selected using stratified random sampling method, to select 192 lecturers, and 377 undergraduate students. Data collected were analyzed using frequency counts and percentages, and T-test to test the only null hypothesis of the study. The study found out that there was an existence of multimedia technologies (MMT) in the institution. Furthermore, the result showed that both lecturers and students hold positive perception about the use of MMT. The result also revealed that do not use all the available MMT in their institution except internet facilities, computer and media players. Furthermore, the study showed that insufficient technical support; integrating MMT into the curriculum is cumbersome; insufficient internet bandwidth and obsolete MMT hinders them from using it for the pedagogic purpose; and they need to travel between walls in other to make use of MMT are some of the challenges they encountered while using MMT. The result also revealed that there is significant difference in the perception of lecturers and students about the use of MMT. Based on the findings, the study recommends that adequate multimedia facilities should be made available in centralized sections or units of the university so as to enhance effective and easy pedagogic service delivery; workshops training and retraining; conferences and symposium should be organized for lecturers, students and administrators to enlighten them on the need for MMT education

    USE OF MULTIMEDIA TECHNOLOGY AMONG THE LECTURER AND STUDENTS OF OSUN STATE UNIVERSITY

    Get PDF
    The aim of this study is to investigate the use of multimedia technology by lecturers and undergraduate students in Osun State University. The study was guided by four research questions. The study adopted descriptive survey design sample was selected using stratified random sampling method, to select 192 lecturers, and 377 undergraduate students. Data collected were analyzed using frequency counts and percentages, and T-test to test the only null hypothesis of the study. The study found out that there was an existence of multimedia technologies (MMT) in the institution. Furthermore, the result showed that both lecturers and students hold positive perception about the use of MMT. The result also revealed that do not use all the available MMT in their institution except internet facilities, computer and media players. Furthermore, the study showed that insufficient technical support; integrating MMT into the curriculum is cumbersome; insufficient internet bandwidth and obsolete MMT hinders them from using it for the pedagogic purpose; and they need to travel between walls in other to make use of MMT are some of the challenges they encountered while using MMT. The result also revealed that there is significant difference in the perception of lecturers and students about the use of MMT. Based on the findings, the study recommends that adequate multimedia facilities should be made available in centralized sections or units of the university so as to enhance effective and easy pedagogic service delivery; workshops training and retraining; conferences and symposium should be organized for lecturers, students and administrators to enlighten them on the need for MMT education

    Vision Matters When It Should: Sanity Checking Multimodal Machine Translation Models

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    Multimodal machine translation (MMT) systems have been shown to outperform their text-only neural machine translation (NMT) counterparts when visual context is available. However, recent studies have also shown that the performance of MMT models is only marginally impacted when the associated image is replaced with an unrelated image or noise, which suggests that the visual context might not be exploited by the model at all. We hypothesize that this might be caused by the nature of the commonly used evaluation benchmark, also known as Multi30K, where the translations of image captions were prepared without actually showing the images to human translators. In this paper, we present a qualitative study that examines the role of datasets in stimulating the leverage of visual modality and we propose methods to highlight the importance of visual signals in the datasets which demonstrate improvements in reliance of models on the source images. Our findings suggest the research on effective MMT architectures is currently impaired by the lack of suitable datasets and careful consideration must be taken in creation of future MMT datasets, for which we also provide useful insights

    HbbTV-compliant Platform for Hybrid Media Delivery and Synchronization on Single- and Multi-Device Scenarios

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    [EN] The combination of broadcast and broadband (hybrid) technologies for delivering TV related media contents can bring fascinating opportunities. It is motivated by the large amount and diversity of media contents, together with the ubiquity and multiple connectivity capabilities of modern consumption devices. This paper presents an end-to-end platform for the preparation, delivery, and synchronized consumption of related hybrid (broadcast/broadband) media contents on a single device and/or on multiple close-by devices (i.e., a multi-device scenario). It is compatible with the latest version of the Hybrid Broadcast Broadband TV (HbbTV) standard (version 2.0.1). Additionally, it provides adaptive and efficient solutions for key issues not specified in that standard, but that are necessary to successfully deploy hybrid and multidevice media services. Moreover, apart from MPEG-DASH and HTML5, which are the broadband technologies adopted by HbbTV, the platform also provides support for using HTTP Live Streaming and Real-time Transport Protocol and its companion RTP Control Protocol broadband technologies. The presented platform can provide support for many hybrid media services. In this paper, in order to evaluate it, the use case of multi-device and multi-view TV service has been selected. The results of both objective and subjective assessments have been very satisfactory, in terms of performance (stability, smooth playout, delays, and sync accuracy), usability of the platform, usefulness of its functionalities, and the awaken interest in these kinds of platforms.This work was supported in part by the "Fondo Europeo de Desarrollo Regional" and in part by the Spanish Ministry of Economy and Competitiveness through R&D&I Support Program under Grant TEC2013-45492-R.Boronat, F.; Marfil-Reguero, D.; Montagud, M.; Pastor Castillo, FJ. (2017). HbbTV-compliant Platform for Hybrid Media Delivery and Synchronization on Single- and Multi-Device Scenarios. IEEE Transactions on Broadcasting. 1-26. https://doi.org/10.1109/TBC.2017.2781124S12

    Policy-Based Dynamic Proxy Framework: An Application Level Infrastructure For Active Service Creation And Contents Delivery

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    This thesis focuses on the dynamic proxy framework named the Chek Proxy Framework (CPF). The main objectives are to scale the existing Internet architecture by conserving the backbone bandwidth, reducing server loads, and improving the overall networking system performance, particularly the client receiving rate. These were achieved by deploying application-level proxy services within the network, to accelerate and customise the delivery of contents. The CPF is based on the 3-tier distributed computing architecture with the client and server residing at the ends of the respective networks. A dynamically appointed middle-tier system, the Dynamic Application Proxy Server (DAPS) is created ondemand and resides at the client-side network based on the designed clustering policy. The uniqueness of CPF lies on the use of voluntary client machines, instead of static and dedicated machines to host DAPS services created at runtime

    Error concealment-aware encoding for robust video transmission

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    In this paper an error concealment-aware encoding scheme is proposed to improve the quality of decoded video in broadcast environments prone to transmission errors and data loss. The proposed scheme is based on a scalable coding approach where the best error concealment (EC) methods to be used at the decoder are optimally determined at the encoder and signalled to the decoder through SEI messages. Such optimal EC modes are found by simulating transmission losses followed by a lagrangian optimisation of the signalling rate - EC distortion cost. A generalised saliency-weighted distortion is used and the residue between coded frames and their EC substitutes is encoded using a rate-controlled enhancement layer. When data loss occurs the decoder uses the signalling information is used at the decoder, in case of data loss, to improve the reconstruction quality. The simulation results show that the proposed method achieves consistent quality gains in comparison with other reference methods and previous works. Using only the EC mode signalling, i.e., without any residue transmitted in the enhancement layer, an average PSNR gain up to 2.95 dB is achieved, while using the full EC-aware scheme, i.e., including residue encoded in the enhancement layer, the proposed scheme outperforms other comparable methods, with PSNR gain up to 3.79 dB
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