Key techniques required for communication processing in multimedia systems are (1) high-speed protocol processing of every data packet and (2) simultaneously processing of many sessions. This paper proposes three solu...
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Key techniques required for communication processing in multimedia systems are (1) high-speed protocol processing of every data packet and (2) simultaneously processing of many sessions. This paper proposes three solutions of high-performance protocol processing: protocol data unit management using page management method, assembling and disassembling of header and contents in hardware, and rescheduling of protocol processing. The feasibility of these techniques have been experimentally verified applying these to the transmission control protocol/internet protocol (TCP/IP) over an fiber-distributed data interface (FDDI) network. As a result, the maximum throughput of 78 Mbps is obtained. The total communication throughput of 64 sessions is 75.6 Mbps, only 3% less than the maximum throughput.< >
The paper discusses the enhanced analysis and simulation capabilities provided by the Communications network Modeling Tool (CNMT) designed by Adroit systems Inc. for Rome Laboratory, Rome NY. The CNMT is a software sy...
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The paper discusses the enhanced analysis and simulation capabilities provided by the Communications network Modeling Tool (CNMT) designed by Adroit systems Inc. for Rome Laboratory, Rome NY. The CNMT is a software system that was developed to provide the National Air Intelligence Center (NAIC) of the Air Force with the ability to analyze telecommunications networks with greater efficiency and accuracy. The CNMT's primary information repository is the NAIC LINKS & NODES (L&N) Sybase database. Data is imported from the L&N database into the CNMT system that was developed using the ARC/INFO geographic information system (GIS). CNMT allows the data to be displayed geographically with existing map data including vector World Data Bank ii and ARC gigitized raster graphics images to enhance the visual relationship between the communications objects and their locations. The CNMT system users are able to develop telecommunications network models for different physical transmission media and overlay logical user network models representing C/sup 2/ chain-of-command hierarchies. Scenario generation provides a flexible, efficient process for defining and loading a combined network with voice and message traffic profiles. Simulation capabilities provide the capability to execute circuit switched and store and forward traffic simulation on network models using a COTS simulation tool (COMNET ii.5) to determine the network's performance characteristics. A collate and display results component provides the capability to further examine the network models and their simulation results.< >
Desktop multimedia may be just the first step toward long-distance multimedia collaboration. This paper describes both the challenges and the opportunities of transmitting high-fidelity multimedia data streams though ...
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ISBN:
(纸本)0897915968
Desktop multimedia may be just the first step toward long-distance multimedia collaboration. This paper describes both the challenges and the opportunities of transmitting high-fidelity multimedia data streams though long distance packet networks, in the context of practical experience with a worldwide videoconference system that operates over a new internet with realtime transmission capabilities. This system conveys full-motion color images and sound at near-VCR quality and is currently in use both as a research testbed and as a production videoconferencing system. It is also designed to support less common shared media such as realtime simulations or digitized maps. Its implementation incorporates a number of unusual features including the adaptation of commercial codecs to a packetized network, use of the ST-iinetwork protocol for bandwidth reservation and multicasting, an experimental media negotiation scheme, and a new `sticky' conferencecontrol protocol designed to minimize the effects of transient network failures and to scale up gracefully to large conferences.
Loyola University Chicago has migrated over the past three years from a set of disjoint, mainframe-based, small-popidation mail systems to a universal, cross-platform, multifunctional mail system. Although the process...
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The Xpress Transfer Protocol (XTP), a full-featured lightweight protocol with mechanisms and functionality specifically design for high-speed network environments, is examined. XTP can provide the full range of servic...
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The Xpress Transfer Protocol (XTP), a full-featured lightweight protocol with mechanisms and functionality specifically design for high-speed network environments, is examined. XTP can provide the full range of services needed to support distributed processing systems. A software implementation of XTP has been completed to run over the BERKOM broadband ISDN network. The performances of XTP over the BERKOM network and an Ethernet are reported and compared to those of TCP/IP (Transmission control Protocol/internet Protocol). XTP has been found to perform about as well as and in some situations better than TCP/IP. A tentative conclusion is that as a full-featured protocol XTP does not gain its performance advantage at the cost of functionality or the other way round.< >
A load processor is a system that has a buffer that can receive load and store it while it is waiting to be processed and has a local decision-making policy for determining if portions of its load should be sent to ot...
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A load processor is a system that has a buffer that can receive load and store it while it is waiting to be processed and has a local decision-making policy for determining if portions of its load should be sent to other load processors. A load balancing system is a set of such load processors that are connected in a network so that (i) they can sense the amount of load in the buffers of neighboring processors and pass load to them, and (ii) so that via local information and decisions by the individual load processors, the overall load in the entire network can be balanced. Such balancing is important to ensure that certain processors are not overloaded while others are left idle (i.e. load balancing helps avoid under-utilization of processing resources). The topology of the network, delays in transporting and sensing load, types of load, and types of local load passing policies all affect the performance of the load balancing system. In this paper, we show how a variety of load balancing systems can be modeled in a discrete event system (DES) theoretic framework, and how balancing properties and performance can be characterized and analyzed in a general Lyapunov stability theoretic framework.
The system is guaranteed theoretically to compress to any feasible rate, with as low a distortion rate as required. It also exhibits user selectable compression and error rates, ability to compress general data types,...
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The system is guaranteed theoretically to compress to any feasible rate, with as low a distortion rate as required. It also exhibits user selectable compression and error rates, ability to compress general data types, and adaptation to the data source. The compression system is based on a novel family of connectionist algorithms and generative algorithms used in conjunction with new artificial neural network models that permit the determination of a quasi-optimal architecture for compressing a given data source.< >
NASA has procured a large scale software development facility, known as the Ground systems Development Environment (GSDE), to support the development of the ground systems software for Space Station Freedom. The GSDE ...
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NASA has procured a large scale software development facility, known as the Ground systems Development Environment (GSDE), to support the development of the ground systems software for Space Station Freedom. The GSDE is geographically distributed and includes Local Area networks (LANs) and T1 lines connecting users at multiple contractor facilities to a mainframe complex at the Johnson Space Center (JSC). In order to assess the adequacy of the planned GSDE network, a discrete event simulation model was developed using networkii.5. In addition to models of each Ethernet segment and each communication link, the network model included detailed models of the architecture of key components, such as routers. A utilization model was developed to estimate the traffic that would be generated by the network users. The simulation model of the GSDE network yielded component utilization, queue lengths, and other performance data. A nominal scenario was simulated, as well as five other potential scenarios that can result in higher network traffic.
This conference proceedings contains 27 papers. The topics discussed are communication protocols;high speed packet networks;broadband networks;telecommunication traffic routing;quality of service;congestion control;ne...
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ISBN:
(纸本)0897915259
This conference proceedings contains 27 papers. The topics discussed are communication protocols;high speed packet networks;broadband networks;telecommunication traffic routing;quality of service;congestion control;networkperformance analysis;media access;asynchronous transfer mode networks;error correction;computer networks;internet;switching networks;multiplexing;image communication;public data networks;distributed database systems;client server networks;multicast communicatiuons;and network measurements.
This paper presents hierarchical control system for compensation & vibration control of flexible material handling robot using neural network for the control parameters scheduling and dynamic control. In this pape...
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