2,965 research outputs found
Satellite-based delivery of educational content to geographically isolated communities: A service based approach
Enabling learning for members of geographically
isolated communities presents benefits in terms of
promoting regional development and cost savings for governments and companies. However, notwithstanding recent advances in e-Learning, from both technological and pedagogical perspectives, there are very few, if any,
recognised methodologies for user-led design of satellite-based e-learning infrastructures. In this paper, we present a methodology for designing a satellite and wireless based network infrastructure and learning services to support distance learning for such isolated communities. This methodology entails (a) the involvement of community members in the development of targeted learning services from an early stage, and (b) a service-oriented approach to learning solution deployment. Results show, that, while the technological premises of distance learning can be
accommodated by hybrid satellite/wireless infrastructures,this has to be complemented with (a) high-quality audio–visual educational material, and (b) the opportunity for community members to interact with other community
members either as groups (common-room oriented scenarios) or individuals (home-based scenarios), thus providing an impetus for learner engagement in both formal and informal activities
Signaling For Multimedia Conferencing in Stand-Alone Mobile Ad Hoc Networks
Mobile ad hoc networks (MANETs) are infrastructure-less and can be set up anywhere, anytime. They can host a wide range of applications in rescue operations, military, private, and commercial settings. Multimedia conferencing is the basis of a wealth of “killer†applications that can be deployed in MANETs. Some examples are audio/video conferencing, multiplayer games, and online public debating. Signaling is the nerve center of multimedia conferences—it establishes, modifies, and tears down conferences. This paper focuses on signaling for multimedia conferences in MANETs. We review the state of the art and propose a novel architecture based on application-level clusters. Our validation employed SIP as the implementation technology and OPNET as our simulation tool. Our clusters are constructed dynamically and the nodes that act as cluster heads are elected based on their capabilities. The capabilities are published and discovered using a simple application-level protocol. The architectural principles and the clustering operations are discussed. Our SIP-based implementation is also presented along with the performance evaluation. Keywords: MANET, SIP-technology, OPNET-simulation tool, cluste
EIES 2 : a distributed architecture for supporting group work
The Computerized Conferencing Center (CCCC) at New Jersey Institute of Technology (NJIT) has been researching on-line group communications for 17 years by developing and studying tools to advance the collective intelligence . The Electronic Information Exchange System 2 (EIES2) provides a research, development and operational environment for distributed computer supported cooperative work (CSCW) systems. The EIES 2 distributed Smalltalk processor provides for rapid prototyping and implementation of muti-media CSCW facilities in the network environment. The Smalltalk support of the object model, and meta-language properties make it ideally suited for incremental development CSCW applications. The EIES2 communication environment supports a decentralized network architecture. Modern standards are used in the implementation of data structures, communication interfaces and database. The EIES2 application layer protocols support use ASN.1 data representation to access to an object-oriented distributed database via X.ROS remote operation services. EIES2 can serve as a foundation on which group work systems may be built and defines protocols that can allow them to inter-operate. An initial system presents a powerful metaphor of conferences and activities which provides an extensible framework upon which to add group work applications. Work to date has provided structures for information exchange, inquiry networking, information filtering, the on-line virtual classroom, and group decision support. This paper presents the system architecture model used for EIES2 and describes the implementation and current applications
An analysis framework for CSCW systems
Software toolkits are under development to help construct applications that support
group-working. Toolkit developers adopt different approaches to group-work support
in order to tackle different issues and a toolkit is commonly characterised by the
approach adopted. It is difficult to compare toolkits because of this lack of apparent
commonality and it is difficult to decide which toolkits meet specific application
requirements. [Continues.
THROUGHPUT IMPROVEMENT AND COMPARATIVE PERFORMANCE ANALYSIS OF INTEGRATED NETWORKS
The demand for high-speed communication continue to increase significantly. Industry forecasts have shown that future data services would contribute to rapid growth in data traffic, with most of this traffic primarily indoors and at hotspots locations. Thus, the deployment and integration of small cell base stations (SCBSs) with Wireless Local Area Network (WLAN) or Wi-Fi is viewed as a critical solution to offload traffic, maximize coverage and boost future wireless systems capacity.
This thesis reviews the existing network of WLAN, Long Term Evolution (LTE) and Worldwide Interoperability for Microwave Access (WiMAX). Tight and Loosely coupled integration of these networks is studied.
More specifically, the introduction of small cell (SC) in loosely coupled Wi-Fi /WiMAX and Wi-Fi/LTE are proposed. These designs are tested in real-time user experience applications consisting of video conferencing, hypertext transfer protocol (HTTP) and email using industrial simulation software, Riverbed Modeler 18.7.
Quality of service parameters was used to analyze these networks. It was found that the throughput of loosely coupled Wi-Fi/WiMAX network can be optimized by small cell. The loosely coupled architecture of Wi-Fi/WiMAX small cell outperforms that of Wi-Fi/LTE small cell. The loosely coupled independently deployed network of Wi-Fi/LTE small cell performs better than the Wi-Fi network. The Wi-Fi/LTE small cell network achieved a substantial rise in downlink throughput in a network consisting of only video conferencing subscriber station
Communication Architecture For Distributed Interactive Simulation (CADIS): Rationale Document Draft
Report is concerned with the necessary communication system protocol data unit standards which must be accepted and adopted for supporting distributed interactive simulation
Field test of quantum key distribution in the Tokyo QKD Network
A novel secure communication network with quantum key distribution in a
metropolitan area is reported. Different QKD schemes are integrated to
demonstrate secure TV conferencing over a distance of 45km, stable long-term
operation, and application to secure mobile phones.Comment: 21 pages, 19 figure
Collaborative design : managing task interdependencies and multiple perspectives
This paper focuses on two characteristics of collaborative design with
respect to cooperative work: the importance of work interdependencies linked to
the nature of design problems; and the fundamental function of design
cooperative work arrangement which is the confrontation and combination of
perspectives. These two intrinsic characteristics of the design work stress
specific cooperative processes: coordination processes in order to manage task
interdependencies, establishment of common ground and negotiation mechanisms in
order to manage the integration of multiple perspectives in design
Communication Architecture For Distributed Interactive Simulation (CADIS): Military Standard (draft)
Report establishes the requirements for the communication architecture to be used in a distributed interactive simulation, including the standards and the recommended practices for implementing the communication architecture and the rationales behind them
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