4,374 research outputs found

    Multimedia Communication

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    Multimedia communication presents information in an interesting, creative way that helps many different types of learners internalize the data. Info graphics are a common example of multimedia communication. These large images are set up like posters and have text, statistics, graphs, charts and images that provide information. Visual learners who need these graphs, charts and images are able to get just as much from the info graph as learners who focus on numbers who, for instance, hone in on the statistics. Websites are also prime examples of multimedia communication. Websites can include all of the different types of media to present a single topic or idea, and they are interactive so that the user can easily find the information and navigate the pages. Many informative websites include videos that offer succinct, engaging clips

    On-board processing satellite network architecture and control study

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    The market for telecommunications services needs to be segmented into user classes having similar transmission requirements and hence similar network architectures. Use of the following transmission architecture was considered: satellite switched TDMA; TDMA up, TDM down; scanning (hopping) beam TDMA; FDMA up, TDM down; satellite switched MF/TDMA; and switching Hub earth stations with double hop transmission. A candidate network architecture will be selected that: comprises multiple access subnetworks optimized for each user; interconnects the subnetworks by means of a baseband processor; and optimizes the marriage of interconnection and access techniques. An overall network control architecture will be provided that will serve the needs of the baseband and satellite switched RF interconnected subnetworks. The results of the studies shall be used to identify elements of network architecture and control that require the greatest degree of technology development to realize an operational system. This will be specified in terms of: requirements of the enabling technology; difference from the current available technology; and estimate of the development requirements needed to achieve an operational system. The results obtained for each of these tasks are presented

    An emerging paradigm or just another trajectory? Understanding the nature of technological changes using engineering heuristics in the telecommunications switching industry

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    The theoretical literature on technological changes distinguishes between paradigmatic changes and changes in trajectories. Recently several scholars have performed empirical studies on the way technological trajectories evolve in specific industries, often by predominantly looking at the artifacts. Much less - if any - empirical work has been done on paradigmatic changes, even though these have a much more profound impact on today's industry. It follows from the theory that such studies would need to focus more on the knowledge level than on the artifact level, raising questions on how to operationalize such phenomena. This study aims to fill this gap by applying network-based methodologies to knowledge networks, represented here by patents and patent citations. The rich technological history of telecommunications switches shows how engineers in the post-war period were confronted with huge challenges to meet drastically changing demands. This historical background is a starting point for an in-depth analysis of patents, in search of information about technological direction, technical bottlenecks, and engineering heuristics. We aim to identify when such changes took place over the seven different generations of technological advances this industry has seen. In this way we can easily recognize genuine paradigmatic changes compared to more regular changes in trajectory.technological trajectories; patents; network analysis; telecommunication manufacturing industry

    Applications of satellite technology to broadband ISDN networks

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    Two satellite architectures for delivering broadband integrated services digital network (B-ISDN) service are evaluated. The first is assumed integral to an existing terrestrial network, and provides complementary services such as interconnects to remote nodes as well as high-rate multicast and broadcast service. The interconnects are at a 155 Mbs rate and are shown as being met with a nonregenerative multibeam satellite having 10-1.5 degree spots. The second satellite architecture focuses on providing private B-ISDN networks as well as acting as a gateway to the public network. This is conceived as being provided by a regenerative multibeam satellite with on-board ATM (asynchronous transfer mode) processing payload. With up to 800 Mbs offered, higher satellite EIRP is required. This is accomplished with 12-0.4 degree hopping beams, covering a total of 110 dwell positions. It is estimated the space segment capital cost for architecture one would be about 190Mwhereasthesecondarchitecturewouldbeabout190M whereas the second architecture would be about 250M. The net user cost is given for a variety of scenarios, but the cost for 155 Mbs services is shown to be about $15-22/minute for 25 percent system utilization

    Proceedings of the Second International Mobile Satellite Conference (IMSC 1990)

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    Presented here are the proceedings of the Second International Mobile Satellite Conference (IMSC), held June 17-20, 1990 in Ottawa, Canada. Topics covered include future mobile satellite communications concepts, aeronautical applications, modulation and coding, propagation and experimental systems, mobile terminal equipment, network architecture and control, regulatory and policy considerations, vehicle antennas, and speech compression

    GUIDELINES FOR THE DESIGN OF ENHANCED, COST EFFECTIVE NETWORKS IN A MANUFACTURING ENVIRONMENT

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    Investigations into the transmission of real-time interactive speech over local area networks (LAN) in an industriai/commerciai environment to eventually obviate the need for a private automatic branch exchange and ultimately prepare the way for a single interactive integrated information system (PS) that provides work stations, which are networked via a LAN, with a fully interactive speech and graphics facility commensurate with the future requirements in computer integrated manufacturing (CIM). The reasons for conducting this programme of research were that existing LANs do not offer a real time interactive speech facility. Any verbal communication between workstation users on the LAN has to be carried out over a telephone network (PABX). This necessitates the provision of a second completely separate network with its associated costs. Initial investigations indicate that there is sufGcient capacity on existing LANs to support both data and real-time speech provided certain data packet delay criteria can be met. Earlier research work (in the late 1980s) has been conducted at Bell Labs and MIT. [Ref 25, 27 & 28], University of Strathclyde [Ref 24] and at BTRL [Ref 22 and 37]. In all of these cases the real time implementation issues were not fijlly addressed. In this thesis the research work reported provides the main criteria for the implementation of real-time interactive speech on both existing and newly installed networks. With such enhanced communication facilities, designers and engineers on the shop floor can be projected into their suppliers, providing a much greater integration between manufacturer and supplier which will be beneficial as Concurrent and Simultaneous Engineering Methodologies are further developed. As a result, various LANs have been evaluated as to their suitability for the transmission of real time interactive speech. As LANs, in general, can be separated into those with either deterministic or stochastic access mechanisms, investigations were carried out into the ability of both the: (i) Token Passing Bus LANs supporting the Manufacturing and Automation Protocol (MAP)ā€”Deterministic and (u) Carrier Sense Multiple Access/Collision Detection (CSMA/CD) LANs supporting the Technical Office Protocol (TOP)ā€” Stochastic to support real time interactive speech, as both are used extensively in commerce and manufacturing. The thesis that real time interactive speech can be transmitted over LANs employed in a computer integrated manufacturing environment has to be moderated following the tests carried out in this work, as follows:- The Token Passing LAN presents no serious problems under normal traffic conditions, however, the CSMA/CD LAN can only be used in relatively light traffic conditions i.e. below 30% of its designed maximum capacity, providing special arrangements are made to minimise the access, transmission and processing delays of speech packets. Given that a certain amount of delay is inevitable in packet switched systems (LANs), investigations have been carried out into techniques for reducing the subjective efifect of speech packet loss on real-time interactive systems due to the unacceptable delays caused by the conditions mentioned above

    A Survey on Quality of Service in the Voice Over IP Technology

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    Voice services can be transmitted by circuit switched and packet switched networks (Internet). Voice over Internet Protocol (VoIP) is one of the most attractive and important service in telecommunication networks, current implementations of VoIP have two main types of architectures, which are based on H.323 and Session Initiation Protocol (SIP). However, when the voice traffic is transported over Internet, the packet based transmission may introduce impairments and it has influence on the Quality of Service (QoS) perceived by the end users. The voice quality of VoIP systems depends on many QoS parameters. Particularly, One Way Delay (OWD), jitter and Packet Loss Rate (PLR) have an important impact on voice quality. This survey presents the main concepts relating to the VoIP technology and quality of service issues

    On the proposed integrated services digital network

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    The ultimate aim of this dissertation is neither to increase the state of the art in networking technology nor to predict the future structure of telecommunications networks. It is an attempt to raise the awareness of both the author and the reader as to the evolutionary forces driving vast changes in the telecommunications field. The impact of these changes will significantly alter the way we live and conduct business in the Information Age. For those involved with the communications field, the ability to make sound business decisions will require an in-depth knowledge of the technology and services that compose ISDN. Therefore this paper will explore the motivating forces, the potential services, and the technical components in the emerging Integrated Services Digital Network (ISDN). My interest in data communications was kindled at RIT and has continued in my work, both as a systems programmer in the telecommunications division at the Travelers Insurance Company and as a printing systems analyst for Xerox Corporation. This thesis has helped me answer both personal and professional questions about the future of telecommunications and to share this information with others
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