Distributed multimedia systems

A distributed multimedia system (DMS) is an integrated communication, computing, and information system that enables the processing, management, delivery, and presentation of synchronized multimedia information with quality-of-service guarantees. Multimedia information may include discrete media data, such as text, data, and images, and continuous media data, such as video and audio. Such a system enhances human communications by exploiting both visual and aural senses and provides the ultimate flexibility in work and entertainment, allowing one to collaborate with remote participants, view movies on demand, access on-line digital libraries from the desktop, and so forth. In this paper, we present a technical survey of a DMS. We give an overview of distributed multimedia systems, examine the fundamental concept of digital media, identify the applications, and survey the important enabling technologies.published_or_final_versio

BETaaS: A Platform for Development and Execution of Machine-to-Machine Applications in the Internet of Things

The integration of everyday objects into the Internet represents the foundation of the forthcoming Internet of Things (IoT). Such “smart” objects will be the building blocks of the next generation of applications that will exploit interaction between machines to implement enhanced services with minimum or no human intervention in the loop. A crucial factor to enable Machine-to-Machine (M2M) applications is a horizontal service infrastructure that seamlessly integrates existing IoT heterogeneous systems. The authors present BETaaS, a framework that enables horizontal M2M deployments. BETaaS is based on a distributed service infrastructure built on top of an overlay network of gateways that allows seamless integration of existing IoT systems. The platform enables easy deployment of applications by exposing to developers a service oriented interface to access things (the Things-as-a-Service model) regardless of the technology and the physical infrastructure they belong

Computer Science and Technology Series : XV Argentine Congress of Computer Science. Selected papers

CACIC'09 was the fifteenth Congress in the CACIC series. It was organized by the School of Engineering of the National University of Jujuy. The Congress included 9 Workshops with 130 accepted papers, 1 main Conference, 4 invited tutorials, different meetings related with Computer Science Education (Professors, PhD students, Curricula) and an International School with 5 courses. CACIC 2009 was organized following the traditional Congress format, with 9 Workshops covering a diversity of dimensions of Computer Science Research. Each topic was supervised by a committee of three chairs of different Universities. The call for papers attracted a total of 267 submissions. An average of 2.7 review reports were collected for each paper, for a grand total of 720 review reports that involved about 300 different reviewers. A total of 130 full papers were accepted and 20 of them were selected for this book.Red de Universidades con Carreras en Informática (RedUNCI

Delivery of Personalized and Adaptive Content to Mobile Devices:A Framework and Enabling Technology

Many innovative wireless applications that aim to provide mobile information access are emerging. Since people have different information needs and preferences, one of the challenges for mobile information systems is to take advantage of the convenience of handheld devices and provide personalized information to the right person in a preferred format. However, the unique features of wireless networks and mobile devices pose challenges to personalized mobile content delivery. This paper proposes a generic framework for delivering personalized and adaptive content to mobile users. It introduces a variety of enabling technologies and highlights important issues in this area. The framework can be applied to many applications such as mobile commerce and context-aware mobile services

A Semantic-Based Middleware for Multimedia Collaborative Applications

The Internet growth and the performance increase of desktop computers have enabled large-scale distributed multimedia applications. They are expected to grow in demand and services and their traffic volume will dominate. Real-time delivery, scalability, heterogeneity are some requirements of these applications that have motivated a revision of the traditional Internet services, the operating systems structures, and the software systems for supporting application development. This work proposes a Java-based lightweight middleware for the development of large-scale multimedia applications. The middleware offers four services for multimedia applications. First, it provides two scalable lightweight protocols for floor control. One follows a centralized model that easily integrates with centralized resources such as a shared too], and the other is a distributed protocol targeted to distributed resources such as audio. Scalability is achieved by periodically multicasting a heartbeat that conveys state information used by clients to request the resource via temporary TCP connections. Second, it supports intra- and inter-stream synchronization algorithms and policies. We introduce the concept of virtual observer, which perceives the session as being in the same room with a sender. We avoid the need for globally synchronized clocks by introducing the concept of user\u27s multimedia presence, which defines a new manner for combining streams coming from multiple sites. It includes a novel algorithm for estimation and removal of clock skew. In addition, it supports event-driven asynchronous message reception, quality of service measures, and traffic rate control. Finally, the middleware provides support for data sharing via a resilient and scalable protocol for transmission of images that can dynamically change in content and size. The effectiveness of the middleware components is shown with the implementation of Odust, a prototypical sharing tool application built on top of the middleware

Parallel replication for distributed video-on-demand systems.

Lie, Wai-Kwok Peter.Thesis (M.Phil.)--Chinese University of Hong Kong, 1997.Includes bibliographical references (leaves 79-83).Abstract --- p.iAcknowledgments --- p.iiChapter 1 --- Introduction --- p.1Chapter 2 --- Background & Related Work --- p.5Chapter 2.1 --- Early Work on Multimedia Servers --- p.6Chapter 2.2 --- Compression of Multimedia Data --- p.6Chapter 2.3 --- Multimedia File Systems --- p.7Chapter 2.4 --- Scheduling Support for Multimedia Systems --- p.8Chapter 2.5 --- Inter-media Synchronization --- p.9Chapter 2.6 --- Related Work on Replication in VOD Systems --- p.9Chapter 3 --- System Model --- p.12Chapter 4 --- Replication Methodology --- p.15Chapter 4.1 --- Replication Triggering Policy --- p.16Chapter 4.2 --- Source & Target Nodes Selection Policies --- p.17Chapter 4.3 --- Replication Policies --- p.18Chapter 4.3.1 --- Policy 1: Injected Sequential Replication --- p.20Chapter 4.3.2 --- Policy 2: Piggybacked Sequential Replication --- p.22Chapter 4.3.3 --- Policy 3: Injected Parallel Replication --- p.25Chapter 4.3.4 --- Policy 4: Piggybacked Parallel Replication --- p.28Chapter 4.3.5 --- Policy 5: Injected & Piggybacked Parallel Replication --- p.34Chapter 4.3.6 --- Policy 6: Multi-Source Injected & Piggybacked Parallel Replication --- p.36Chapter 4.4 --- Dereplication Policy --- p.37Chapter 5 --- Distributed Architecture for VOD Server --- p.39Chapter 5.1 --- Server Node --- p.40Chapter 5.2 --- Movie Manager --- p.42Chapter 5.3 --- Metadata Manager --- p.42Chapter 5.4 --- Protocols for Distributed VOD Architecture --- p.43Chapter 5.4.1 --- Protocol for Servicing New Customers --- p.43Chapter 5.4.2 --- Protocol for Servicing Existing Customers --- p.45Chapter 5.4.3 --- Protocol for Single/Multi-Source Injected & Parallel Replication --- p.46Chapter 5.4.4 --- Protocol for Dereplication --- p.48Chapter 5.5 --- Failure Handling --- p.49Chapter 5.5.1 --- Handling of Server Node Failures --- p.50Chapter 5.5.2 --- Handling of Movie Manager Failures --- p.52Chapter 6 --- Results --- p.55Chapter 6.1 --- Performance Metric --- p.56Chapter 6.2 --- Simulation Environment --- p.58Chapter 6.3 --- Results of Experiments without Dereplication --- p.59Chapter 6.3.1 --- Comparison of Different Replication Policies --- p.60Chapter 6.3.2 --- Effect of Early Acceptance/Migration --- p.61Chapter 6.3.3 --- Answer to the Resources Consumption Tradeoff issue --- p.62Chapter 6.3.4 --- Effect of Varying Movie Popularity Skewness --- p.64Chapter 6.3.5 --- Effect of Varying Replication Threshold --- p.64Chapter 6.3.6 --- Comparison of Different Target Node Selection Policies --- p.65Chapter 6.4 --- Overall Impact of Dynamic Replication --- p.66Chapter 7 --- Comparison with BSR-based Policy --- p.71Chapter 8 --- Conclusions --- p.75Chapter 8.1 --- Summary --- p.75Chapter 8.2 --- Future Research Directions --- p.76Bibliography --- p.7