254 research outputs found
Overview of a media convergence centre (MC2)
Organizational alliances are rapidly being formed as a means for effective cooperation with a common goal within a targeted value chain. The combination of such communication, coordination and cooperation leads to new organisational forms and scenarios within the Digital Ecosystem space that require technological support. Convergence refers to the move towards the use of a single united interaction medium and media. Such a solution enables telecommunications services that are concurrently coupled with enterprise and internet data. Due to the versatile nature of today's extended enterprise, a flexible, feature-rich, adaptive and widely accessible converged solution is required.This paper proposes a Media Convergence Centre (MC:) solution that allows users to participate in a converged multimedia collaboration network using a variety of interaction devices in an easy and convenient manner
GUIDELINES FOR THE DESIGN OF ENHANCED, COST EFFECTIVE NETWORKS IN A MANUFACTURING ENVIRONMENT
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)—Deterministic
and
(u) Carrier Sense Multiple Access/Collision Detection (CSMA/CD) LANs
supporting the Technical Office Protocol (TOP)— 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
Space Shuttle/TDRSS communication and tracking systems analysis
In order to evaluate the technical and operational problem areas and provide a recommendation, the enhancements to the Tracking and Data Delay Satellite System (TDRSS) and Shuttle must be evaluated through simulation and analysis. These enhancement techniques must first be characterized, then modeled mathematically, and finally updated into LinCsim (analytical simulation package). The LinCsim package can then be used as an evaluation tool. Three areas of potential enhancements were identified: shuttle payload accommodations, TDRSS SSA and KSA services, and shuttle tracking system and navigation sensors. Recommendations for each area were discussed
A Simulation Study of a Limited Sensing Random Access Algorithm for a Local Area Network with Voice Users
The purpose of this work is to evaluate the perfonnance of a limited sensing random access algorithm in a local area network with voice users. Random access algorithms have proven to be very efficient in local area network environments with data users. However, in contrast to data packets, voice packets cannot be allowed to experience long delays, because of the requirement that a voice data stream must be played out at the receiver. If a voice packet does exceed its established maximum delay, it is discarded. This simulation study finds the number of voice users that a network can support, provided the packet loss rate that can be tolerated by a customer does not exceed a certain threshold. Finally, a comparison is made with the simulation results of this algorithm with other commonly used protocols
Public service user terminus study compendium of terminus equipment
General descriptions and specifications are given for equipments which facilitate satellite and terrestrial communications delivery by acting as interfaces between a human, mechanical, or electrical information generator (or source) and the communication system. Manufactures and suppliers are given as well as the purchase, service, or lease costs of various products listed under the following cateories: voice/telephony/facsimile equipment; data/graphics terminals; full motion and processes video equipment; and multiple access equipment
Inter-organisational infrastructures for competitive advantage : strategic alignment in virtual corporations
xxii+216hlm.;24c
Sistema inteligente de gestão de serviços heterogéneos de videoconferência
Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores - Major Telecomunicações. Faculdade de Engenharia. Universidade do Porto. 200
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