A Survey of Distributed Multimedia Research, Standards and Products
A Survey
of Distributed Multimedia
Research, Standards and Products
Edited by Chris Adie
Edinburgh University Computing Service
University Library Building
George Square
Edinburgh
EH8 9LJ
Great Britain
First Edition - 25 January 1993
RARE Project OBR(92)046v2
R seaux Associ s pour la Recherche Europ enne
Singel 466-468, NL-1017 AW
AMSTERDAM
Netherlands
Table of Contents
Disclaimer 2
Availability 2
Acknowledgements 3
1. Introduction 4
1.1. Background 4
1.2. Scope 4
1.3. Methods 5
1.4. Format 6
1.5. Future 8
2. Research 9
3. Standards 69
4. Products 111
5. Wide-Area Information Servers 147
Appendix 1: RARE Multimedia Working Group 154
Appendix 2: Obtaining Standards Documents 155
Disclaimer
This survey report is based on information supplied to or
obtained by Edinburgh University Computing Service (EUCS)
in good faith. Neither EUCS nor RARE nor any of their
staff may be held liable for any inaccuracies or
omissions, or any loss or damage arising from or out of
the use of this report.
Mention of a product in this report does not constitute
endorsement either by EUCS or by RARE.
All trademarks are hereby acknowledged as being the
property of their respective owners.
Availability
This document is available in various forms (PostScript,
text, Microsoft Word for Windows 2) by anonymous FTP
from:
ftp.edinburgh.ac.uk:pub/mmsurvey
Paper copies are not available.
Acknowledgements
This survey would have been an impossible task for one
person working alone. Sincere thanks are due to the
individuals who have contributed information to the
report. Some people have contributed snippets or
isolated facts, some have written up individual entries
for the report, and some (mainly my colleagues at
Edinburgh) have written up a number of entries. It would
be difficult to indicate in the report exactly who wrote
what, so I simply record my gratitude to all the
contributors listed below. The list contains both those
who explicitly provided information, and those whose
text, adapted by me for this survey, originally served a
different purpose. Inevitably, some names will have been
missed out, and I apologise for this. Naturally, as
Editor I take responsibility for any mistakes in the
report, but these people deserve the credit.
Chris Adie
C.J.Adie@edinburgh.ac.uk
25 January 1993
Mark Adler
Marni Armstrong
Ran Atkinson
Richard Bacon
Tim Berners-Lee
Scott Brim
Andrew Cole
Jon Crowcroft
Terry Crowley
Ken Currie
Scott Currie
Nigel Davies
Paul Dourish
Jack Drescher
Chip Elliott
Carlos Escobar
Domenico Ferrari
Anastassios Gavras
Norbert Gerfelder
Brian Gilmore
Gita Gopal
Steven Grady
Gabriela Grolms
Steve Hailes
Judson Harward
Grant Henderson
Paul Hill
Rune Hjelsvold
Rachel Jones
Ralf Keller
Steve Krause
David Lowrie
Dave Mercer
Mark Moran
Toby Morris
Alastair Munro
Burkhard Neidecker-Lutz
Teun Nijssen
Ari Ollikainen
Larry Palmer
Earl Rennison
Frank Ruge
Joe Schlesak
Henning Schulzrinne
Charles Sederholm
Sandy Shaw
Eduardo Shoval
Brian Smith
Tage Stabell-Kulo
Graham Storrs
Cindy Walden
Sylvia Wilbur
Lars Wolf
Graeme Wood
Edward Vielmetti
1. Introduction
1.1. Background
One of the results of the application of digital
electronics to the fields of audio and video engineering
has been the emergence of a new "multimedia" computer
technology, which enables the integration of text,
graphics, sound and video images. Multimedia computing
is expanding quickly into a number of new application
areas, such as video conferencing and CAL. Such areas
are of particular relevance to computer users in the
research and academic community.
In view of this, it is appropriate that academic
computing and network service providers should consider
how best to offer multimedia services to their customers.
In today's highly distributed computing environment, it
is particularly important that networking aspects of
multimedia services should be investigated.
The RARE organisation, which looks after the networking
needs of European researchers, has recently set up a
Working Group on Multimedia Networking. One of the first
actions of the group was to commission this survey of the
state-of-the-art in multimedia networking. Details of
the RARE group are given in an appendix.
The aim of the survey is to identify existing work of
three distinct types.
Research A number of academic research groups in
Europe, the United States and elsewhere
are investigating the provision of
multimedia services across local and wide
area networks. Many commercial
organisations are also undertaking
research in this area.
Standards The survey covers not only the standards
being produced by standards bodies such as
the CCITT and ISO, but also the
proprietary and de facto standards which
are emerging in the marketplace.
Products There are already a number of commercial
products available which offer distributed
multimedia capabilities, including
videoconferencing.
The intended readership of this survey report is
computing professionals with a knowledge of networking in
an academic/research environment.
Given the short timescale yet wide remit of this survey,
it of course cannot aspire to be fully comprehensive.
Nevertheless, the editor believes that the major research
projects, standards and products are included.
1.2. Scope
The field of distributed multimedia is expanding very
quickly. In order to keep the size of the survey within
manageable bounds, it is necessary to impose strict
limits on what is included.
As far as research is concerned, the survey concentrates
on current research - in practice this means that to be
included a research project must have been underway in
1992. The survey does not cover research in areas (such
as high-speed networks) which are of more general
relevance. CSCW (computer-supported co-operative
working) is viewed as a separate (although related)
research field, and has not been covered.
Both de jure and industry/de facto standards are included
in the survey. Standards are included if they are:
relevant to multimedia networking
cross-platform
unlikely to be familiar to networking professionals
This means that standards such as ATM and ISDN, which are
certainly relevant to multimedia networking, are not
included because many networking professionals are likely
to be familiar with them.
At the request of the RARE Working Group, the scope of
the survey has been expanded to cover compound document
interchange standards. Some products which provide this
functionality have also been included.
Multimedia networking "products" include
freeware/shareware packages and freely-available research
tools as well as commercial offerings. There are some
specific areas where the products part of the survey is
deliberately incomplete:
Mailers which support MIME are sufficiently numerous
that a separate survey might be appropriate. They have
not been listed in the survey, except for Metamail,
which is a toolkit rather than a complete application.
There are several commercial PC-based mail products
which offer similar proprietary multimedia
capabilities. Microsoft Mail has been selected as a
representative of this class of product.
The report does not cover "traditional"
videoconferencing products, concentrating instead on
the emerging "desktop" conferencing paradigm which
centres on the use of computer workstations.
Many recent database packages claim to be multimedia-
capable and networkable. Often, this amounts to no
more that an ability to store image data in a record,
and to retrieve it from a network fileserver. Such
packages have not been included.
Several entries which were submitted for inclusion in the
survey have been omitted, because they did not fall
within these fairly strict rules.
1.3. Methods
The following methods were used in gathering data for
this survey.
1. A questionnaire was prepared and distributed on the
Internet, to the newsgroups comp.multimedia,
comp.mail.multi-media, comp.protocols.iso and
comp.compression. Copies were also send to the
mailing lists wg-imm@rare.nl and rem-conf@es.net. The
response to this questionnaire was most gratifying
(over 100 messages), and probably the majority of
entries in this report are derived directly or
indirectly from this source. Some responses are
included in the survey almost verbatim; others
underwent considerable editing.
2. Published research papers were an excellent source of
information on both research projects and standards.
The April 1991 issue of Communications of the ACM and
the May 1992 issue of IEEE Communications Magazine
were particularly useful.
3. For the Products section, manufacturers' sales
literature and (particularly in the case of freeware
products) product manuals provided a lot of useful
information. Of course, information from sales
literature must always be taken with a grain of salt,
and readers of this report are reminded that product
evaluation did not form part of the survey process.
4. Informal contacts by, and existing knowledge of, the
editor and his colleagues provided the information for
many entries. For some (but not all) of the research
entries arising from this information source, the
research project leader was asked to validate the
final text of the entry.
5. For standards, the standards documents themselves were
consulted where possible. Information about some
CCITT standards was taken from the ITU Teledoc server.
Information on how to obtain RFC documents and on how
to access the Teledoc server is given in an appendix.
1.4. Format
Research projects are covered in chapter 2, standards in
chapter 3 and products in chapter 4. Chapter 5 contains
information about the three most important wide-area
information server systems, which do not conveniently fit
into any of the other categories, but nevertheless have
significant potential for wide-area access to multimedia
resources. At the start of each chapter is a list of its
contents.
It has not proved possible within the timescale of the
survey to obtain full information about every entry.
Therefore, in each chapter there are two classes of
entry:
Fully-recorded entries, where a well-defined set of
information is recorded about each item. Such entries
occupy from one to two pages.
Minimal entries, where relatively little information
(almost no information in some cases) is available
about the item. Such entries are only a few lines
long.
The information recorded is naturally different for
research projects, standards and products. However,
there is one field which is included in all entries,
irrespective of type: Date of entry. This is the date
on which the information was recorded or last changed.
Its purpose is to indicate the currency of the
information, and will be particularly useful if this
document is later updated.
1.4.1. Research Projects
The information recorded (where known) for each research
project is as follows:
Project name: The name of the research project. Most
projects have a catchy name or acronym
(but there are one or two exceptions).
Funding body: The organisation(s) which sponsor the
research project.
Participants: The organisation(s) which are involved in
carrying out the research project.
Timescale: The starting and finishing dates of the
project.
Project aims: The formal aims of the project.
Description: One or two pages describing the project,
including progress to date if known.
Standards used: If the research makes use of any
standards which are described in the
Standards section of the survey, they are
recorded here.
Papers/reports: Publications or reports which have
resulted from the research.
Contact point: The name and address of an individual who
can be contacted for further information
about the research project. This is often
the project leader.
1.4.2. Standards
The information recorded (where known) for each standard
is as follows:
Name: The name by which the standard is commonly
known. This is almost never its formal
title.
Reference: The reference number for the standard, if
it has one.
Version: The version of the standard which is
described.
Sponsoring body: The organisation(s) which promote the
standard.
Status: The formal status of the standard.
Brief description: The formal title of the standard is
often given here.
Detailed description: From one to two pages describing
the standard, giving background
information, mentioning its area of
application, and giving some technical
detail. This is often derived from the
introduction to the standards document, or
(for CCITT documents) from the CCITT
Teledoc server; or it may have been
specially written by a contributor.
Products: Any products (not necessarily just those
which appear in the products section of
the report) which make use of or implement
the standard.
Further information: Where to obtain further details
about the standard. Information on
obtaining standards documents is given in
an appendix.
In this chapter, ISO/CCITT standards are listed first,
followed by Internet specifications, and finally
proprietary standards.
1.4.3. Products
Name: The name of the product
Version: Product version number
Manufacturer: Name and address of the manufacturer or
(for shareware/freeware products) the
author, with Email address if known.
Platform: The hardware and software systems on which
the product will run.
Description: Up to two pages of text describing the
product and its function. For freeware
products, this is often taken from the
documentation or readme file. For
commercial products, it generally derives
from sales information or from a
contributor.
Future plans: The manufacturer's or author's future
plans for the product.
Available from: For commercial products, the name and
address of supplier (if different from the
manufacturer). For freeware/shareware,
address of an FTP site where the product
may be obtained.
Price: Usually in the currency of the country of
origin.
Standards: If any of the standards described in the
Standards section of this report are used
in the product, they are mentioned here.
Further information: This section refers to any
product reviews, documentation, etc.
In this chapter, conferencing products are listed first,
followed by a smaller number of products in other
categories.
1.5. Future
Discussions as to the best way of keeping this document
up-to-date are in progress. In the interim, the present
editor (C.J.Adie@edinburgh.ac.uk) has agreed to record
any errata and new information of which he is made aware.
You are encouraged to send new information and
corrections to this address.
It is possible that the Conferencing section of the
Products chapter will be maintained separately from the
rest of this document. Tom Sandoski (tom@concert.net)
has agreed to compile a catalog of conferencing products,
starting with the information in this report.
2. Research
SRI/ETRI 11
Lancaster/ICI 12
AthenaMuse 2 13
BERKOM 15
CAR 18
CIO 19
CoMMedia 22
DARPA Remote Conferencing 24
DEMON 26
EuroBridge 27
HeiProjects 28
ISLE/EVAN 29
JIPS Videoconferencing 31
JITOL 32
Libernet.91 33
MADE 34
MCRL 35
MIAS 37
MICE 38
MNI 40
MOST 41
Multi G 42
Multimedia RPC 43
MUMS 44
OSI 95 45
PACT 47
Palantir 48
Pegasus 49
Plateau 51
QOS-A 52
Rapport 53
SUMO 54
TEMPO 55
Tenet 56
TMPI 58
Touring Machine 60
XMovie 63
Zenith 65
[BBN] 66
[ACME] 66
[ACT] 66
[CAVECAT] 66
[DSI] 66
[ELISE] 66
[Etherphone] 67
[GUIDANCE] 67
[Hydra] 67
[IMEX] 67
[ISA] 67
[Liveboard] 67
[MediaSpace] 67
[MERMAID] 67
[MMT] 67
[Pandora] 68
[PREPARE] 68
[TeamWorkStation] 68
[TINA] 68
Project name: (none)SRI/ETRI
Funding body: Electronics and Telecommunications
Research Institute (ETRI) (KR)
Participants: SRI International (US)
ETRI (KR)
Samsung
Lucky Gold Star
DaeWoo
Timescale: January 1991 to April 1994
Project aims: To develop an Integrated Multimedia User
Interface for the Intelligent Computer,
InCom
Description: Integrated Multimedia I/O Interface (MuX)
for Intelligent Computing
Standards used: RTP (modified version), MPEG, JPEG
(with a non-standard hierarchical
compression extension), G.711, G721,
H.261, MIDI
Papers/reports: "A Multimedia Data Processing Model
for a Distributed Multimedia I/O System",
R. Baker et. al., Proceedings of the Third
International Workshop on Networking and
Operating System Support for Digital Audio
and Video, San Diego, November 1992.
"A Synchronization and Integration Model
for Audio, Video, and Time-Based Graphics
Multimedia", D. Kim et. al., Proceedings
of the 2nd Pacific Rim International
Conference on Artificial Intelligence Vol.
II, p1093.
"MuX: An X Co-Existent, Time-Based
Multimedia I/O Server", E. Rennison et.
al., X Technical Conference Proceedings,
January 1992.
Contact point: Earl Rennison (rennison@erg.sri.com)
SRI International
333 Ravenswood Avenue
Menlo Park
CA 94025
USA
Phone: +1 415 859 5201
Fax: +1 415 859 4812
Date of entry: 18 January 1993
Project name: (none)Lancaster/ICI
Funding body: ICI plc (GB)
Participants: University of Lancaster (GB)
ICI plc (GB)
Timescale: Commenced January 1991
Project aims: To investigate in detail the capabilities
of emerging distributed and multimedia
technologies.
To carry out an in-depth investigation of
existing multimedia applications.
To interact with end users (within ICI) to
determine areas of exploitation of
distributed and multimedia technology.
To develop a target application as a
result of the previous investigations to
demonstrate a potential useful
exploitation of multimedia technology.
Description: Formal title: "Multimedia Applications:
User Requirements and Technology Support"
A broad study of the current state of the
art in multimedia applications and
technology has been conducted. This study,
in conjunction with the results of
interaction with end-users in ICI has led
to the identification of a number of
possible application areas. Work is now
progressing to explore each of these areas
in more detail.
Standards used:
Papers/reports:
Contact point: The Distributed Multimedia Research Group
Computing Department
Lancaster University
Bailrigg
Lancaster LA1 4YR
Great Britain
Date of entry: 21 December 1992
Project name: AthenaMuse 2AthenaMuse 2
Funding body: AthenaMuse Software Consortium
Participants: About 15 industrial, academic and
government members
Timescale: Commenced 1992
First public release scheduled for January
1994.
Project aims: To convert the research agenda and
experience of AthenaMuse 1 into an
extensible object-oriented software
environment of industrial calibre.
[The aim of AthenaMuse 1 was "to provide
an flexible, powerful, and friendly
prototype multimedia authoring environment
based upon multiple application
paradigms".]
Description: The AthenaMuse Software Consortium is an
industrially sponsored research and
development consortium at MIT. The goal of
the Consortium is to produce an authoring
environment for creating distributed,
multimedia computing applications. This
group is part of the MIT Center for
Educational Computing Initiatives (CECI).
It builds directly on the extensive
research in multimedia computing done by
Project Athena's Visual Computing Group
(VCG). The staff of the Consortium
consists of former members of the VCG,
participants from the sponsoring companies
and new MIT CECI staff members.
The Consortium targets near-term, pre-
competitive technologies that will enable
the delivery of multimedia software.
Existing standards are used when possible,
and new, de facto standards established
when necessary. Fully functional reference
implementations are developed that are
sufficiently robust to be widely used and
evaluated by MIT and industrial
participants. Companies that join the
Consortium receive royalty-free rights to
the software, and are encouraged to
commercialise it.
Multimedia addresses a broad spectrum of
markets and will make use of many near-
term technologies. In this regard, the
following technologies are expected to be
widely available to workstations within
the next five years:
100+ MIP CPUs
Flat panel, megapixel, 24 bit colour
displays
Enormously extended memory
Compatibility with gigabit networks
The research undertaken by the Consortium
centres on three major tasks:
The creation of a platform-independent,
multimedia authoring environment. The
authoring environment, called AthenaMuse
2, is based on the extensive work done
at MIT under Project Athena. The primary
target platforms for this software
system are UNIX-based workstations
running the X Window System. However,
the software and resulting applications
will be portable across diverse hardware
architectures and operating systems
subject to the reasonable constraints of
the hardware's functionality.
The development of multimedia network
services, including the transmission of
digital video, the manipulation of
remote multimedia databases, and
collaborative software editors. The
Consortium intends to design and create
both the server and client software for
such network services.
The creation of a range of exemplar
multimedia applications in diverse areas
spanning education and industry. These
applications will enable the Consortium
to set priorities on enhancements to the
multimedia authoring environment that
are closely linked to the actual needs
of application developers.
This effort will ensure that the
multimedia-enabling software developed by
the Consortium will be consistent with
open systems standards, will be available
to MIT computing initiatives both present
and future, and will have sufficiently
diverse industrial support to have an
impact on international multimedia
computing. Co-operative arrangements
already in place with the Smithsonian
Institution, Bibliotheque de France,
Harvard's Collection of Historic
Scientific Instruments, and other
institutions and universities pursuing
near-term solutions to multimedia
development, will be maintained and
extended. The combination of multi-
vendor, industrial sponsorship and ties to
major institutions that use multimedia
computing, as well as the Consortium's
ongoing relationships with other
universities, offer the prospect that the
merged effort will create a de facto
standard for multimedia computing.
Standards used: Still under discussion. AM 2 will
definitely employ/support: DVI, JPEG, and
the QuickTime Movie format. Other media
and document formats are under
consideration.
Papers/reports: "The AthenaMuse 2 Functional
Specification", CECI(MIT) Report, May
1992.
"The AthenaMuse2 Architecture", CECI(MIT)
Report, August 1992.
The preceding AthenaMuse 1 project is
documented in the reports below:
"A Construction set for Multimedia
Applications", M. Hodges, R. Sasnett and
M. Ackerman, IEEE Software, p37, January
1989.
"Virtual Video Editing in Interactive
Multimedia Applications", W. Mackay and
G. Davenport, Communications of the ACM,
p 802, July 1989.
"Musings on Multimedia", M. Hodges, R.
Sasnett and J. Harward, UNIX Review,
p83, February 1990.
"AthenaMuse Data Description Language",
M. Hodges, R. Sasnett, and E.
Schlusselberg, CECI Report, MIT, 1992.
Contact point: Judson Harward (jud@ceci.mit.edu)
Date of entry: 18 January 1993
Project name: BERKOM (Berlin Communication System)BERKOM
Funding body: DBP Telekom (DE)
Berlin Senate (1986-1991) (DE)
participating industrial enterprises
Participants: Apple Computer GmbH
Apple Deutschland GmbH
Alcatel SEL
Linotype-Hell AG
PAC Technology GmbH
Universitaet des Saarlandes
Axel Springer Verlag AG
Burda GmbH
U.E. Sebald Druck und Verlag GmbH
ART+COM Forschungs- und
Entwicklungszentrum fuer
rechnergestuetztes Gestalten und
Darstellen e.V.
Technische Universitaet Berlin
Fraunhofer Institut fuer Graphische
Datenverarbeitung
Media Port Berlin GmbH
BERCOS GmbH
Communications Broadband Multimedia Inc.
(US)
Deutsches Herzzentrum Berlin
Siemens Nixdorf Informationssysteme AG
Du Pont de Nemours Bad Homburg GmbH
Siemens AG Unternehmensbereich KWU
Robert Bosch GmbH
Digital Equipment GmbH
CEC
IBM Deutschland GmbH
ENC
Liebing&Ullfors EDV Programmentwicklung
GmbH
Gesellschaft fuer Mathematik und
Datenverarbeitung (GMD)
MC Telecommunication Consulting GmbH
Magirus Datentechnik GmbH
FAST-Electronic
Logibyte
NETFOX GmbH
OPTIBASE Inc. (US)
3V Multimedia
eps Bertelsmann GmbH
Fernuniversitaet Hagen
PrePrint Publishing Consulting GmbH
Hewlett Packard GmbH
Sietec Systemtechnik GmbH u. Co. OHG
Lufthansa Informationstechnik und Software
GmbH (LIS)
Institut fuer Zukunftsstudien und
Technologiebewertung
Universitaet Stuttgart
Timescale: 1986 to 1992. Due to organisational
changes, BERKOM changed its project status
to an unlimited work programme from
January 1993 and is now a company:
De.Te.Berkom GmbH.
Project aims: To promote the development of
telecommunication services and end-systems
for Broadband-ISDN or IBCN (Integrated
Broadband Communication Network)
Description: In order to achieve the aim of BERKOM,
issues related to network architecture,
new applications, techniques and end
systems for multimedia communication have
been elaborated. The BERKOM programme
consists of approximately 60 different
projects involving the main computer
manufacturers, user groups, the Deutsche
Bundespost Telekom and research
institutions in Berlin, elsewhere in
Germany and abroad. In realising the
programme two main objectives could be
distinguished. On the one hand broadband
services applications have been realised
in application projects and on the other
hand contributions to the definition of a
Reference Model for integrated (narrow-
and broadband) telecommunication services
have been elaborated. This procedure has
been supported by innovative methods of
market studies, aiming at the
identification of possible potential
demand for broadband communication and its
priorities.
The BERKOM Reference Model was the basis
for identifying, structuring, classifying
and modelling the required software and
hardware components for the development of
multimedia end systems and applications.
It is based on the architectural
principles of the ISO OSI Reference Model.
While the OSI model focuses mainly on
point-to point communication between
functionally equivalent entities, the
BERKOM Reference Model develops additional
concepts and mechanisms for the co-
operation of diverse functional entities
to provide a framework for the development
of autonomous co-operative applications.
New results from ISO/CCITT standardisation
work have been included in the model.
The work on the Berkom Reference Model has
been carried out by all project partners
and has been proposed for international
standardisation (CCITT/OSI) by the
Deutsche Bundespost Telekom. The
application projects have mainly been
concerned with the following areas:
Telepublishing, Video Communication,
Broadband Information Systems, Computer
Integrated Manufacturing (CIM) and
Multimedia Document Communication.
An essential task within the BERKOM
working programme is the realisation of
the BERKOM service concept by providing
multimedia workstations for office
communication. Technical components have
been developed which are applicable for TV
and video communication terminals and
office terminal.
The BERKOM test network is a B-ISDN
network based on fibre-optic
infrastructure. The core network is based
on two STM switches offering subscriber
channels of up to 140 Mbit/s. In 1989 an
ATM switch was introduced in the core
network as well. Interworking units
(IWUs) and network adapter cards have been
developed. The IWUs have been developed
to permit the connection of LAN types like
Ethernet, Token Ring and FDDI to the
BERKOM test network. The adapter cards
have been developed to connect computer
systems with standard busses (eg VME, AT,
Microchannel) to the test network.
The work programme up to the end of 1994
focuses on the development of a common
communication- and service platform based
on the Reference Model . The activities
related to the communication platform
comprise adaptation to local network
islands spread over Germany, intraworking
within the islands as well as interworking
between the islands. In addition to the
LANs already connected to the BERKOM test
network, local ATM is being introduced. As
long as public ATM connections are not
available, the VBN will be used for
interconnection of islands. Interworking
will be achieved through the use of one
common protocol stack, which takes the new
techniques of ATM based B-ISDN into
account while offering communication
functionality well suited to multimedia
services. The service platform will offer
to the multimedia applications two
Multimedia teleservices, namely Multimedia
Mail and Multimedia Collaboration. Both
platforms are being realised on multi-
vendor equipment. While the activities
within the last years have been more
research oriented, the later commercial
establishment is now one important aspect
as well.
Standards used: In the Berkom Reference Model and
within the RACE project ESP (R1091) the
standards which were expected to be the
most applicable to multimedia
communication via the Berkom Test Network
have been studied and recommended. It was
up to the projects which of the standards
were to be used. For further information
refer to [5] below.
Papers/reports: The most important papers describing
the Berkom Reference Model and the Berkom
projects are listed below. For further
information the reader is referred to the
contact point.
[1] BERKOM Reference Model: Application-
Oriented Layers. Version 4.0.1 -
December 1992
[2] BERKOM Reference Model: Lower
Layers. Version 2.0 - February 1991
[3] Evaluation of Existing
Communication Standards and Mapping on
Requirement Analysis (upper layers).
RACE-Project 1091
(91/DTC/ESP/DS/A/001/b1) June 1990
[4] Specification of Protocol Profiles
Based on Existing Standards (lower
layers). RACE-Project 1091
(91/DTC/ESP/DS/A/002/b1) May 1991
[5] "BERKOM Broadband Communication
within the Optical Fibre Network", H.
Ricke and J. Kanzow (Ed.) 1992, ISBN 3-
7685-1392-0
[6] The BERKOM Multimedia Collaboration
Teleservice, Release 2.0, October 1992
[7] The BERKOM Multimedia Mail
Teleservice, Release 2.0, October 1992
[8] The BERKOM Multimedia Transport
System, Release 2.0, October 1992
Contact point: DETECON Technisches Zentrum Berlin
Voltastra.e 5
D-1000 Berlin 65
Germany
Phone: +49 30 467010
Fax: +49 30 46701444
Date of entry: 18 January 1993
Project name: CARCAR
Funding body:
Participants: University College London (GB)
Timescale:
Project aims:
Description: A multimedia conferencing environment
intended for use in the car industry has
been built. It allows sharing of both
custom-built and unmodified X
applications. Shared pointers are provided
so that all participants can see the
entity being indicated by the floor
holder. Audio is provided by n-1 way
mixing and video is switched automatically
as the floor holder changes.
The system has been used for a number of
demonstrations and for a collaborative
authoring exercise. It is now being
adapted to provide digital audio and video
support, and being used in a series of
three evaluation exercises, which will
include interworking with designers in
Europe.
Standards used:
Papers/reports:
Contact point: J Crowcroft (J.Crowcroft@cs.ucl.ac.uk)
Department of Computer Science
University College London
London
Great Britain
Date of entry: 18 January 1993
Project Name: CIO (Co-ordination, Implementation &
Operation of Multimedia Services)CIO
Funding body: RACE Programme (Commission of the European
Community)
Participants: DETECON Technisches Zentrum Berlin (DE)
ACOTEC GmbH (DE)
Ascom Tech Ltd. (CH)
Centro de Estudos de Telecomunicacoes (P)
DBP TELEKOM and Affiliates (FTZ) (DE)
Eidgenossische TH Zurich (CH)
Gesellschaft fur Mathematik und
Datenverarbeitung (DE)
INTERSIS Automacao, s.a. (PT)
Media Port Berlin GmbH (DE)
Norwegian Telecom Research (NO)
Royal PTT Nederland NV (NL)
SIEMENS AG (DE)
SIEMENS AS (NO)
Technische Universitat Berlin (DE)
TELEFONICA (ES)
Universitat Stuttgart (DE)
Universitat Ulm (DE)
Universitat de Liege (BE)
Timescale: January 1992 to December 1994
Project aims: To specify and implement prototypes of two
advanced multimedia teleservices: a
Multimedia Messaging Service; and a Joint
Viewing and Tele-Operation Service.
Description: Two advanced multimedia teleservices: a
Multimedia Messaging Service (MMMS - ie
electronic mail) and a Joint-Viewing and
Tele-Operation Service (JVTOS) are
specified and prototyped on various end
systems. In this context, "teleservices"
refer to distributed multimedia
applications provided in a unified form on
a variety of system platforms to a large
user community - akin to traditional
telephone or telex services.
The teleservices are based on a
communication platform which encompasses:
interworking units and user network
interfaces for selected set of network
technologies;
lower layer protocols to provide
communication between network systems
and terminal equipment/end systems
connected to different network
technologies;
a broadband transport protocol with a
service interface common to all end
systems which allows to specify quality
of service parameters for asynchronous
and likewise isochronos teleservices.
Besides ATM as the basic switching
technology for future IBC, the selected
IBC islands will incorporate FDDI as
backbone for Ethernet LANs. After a
possible later interconnection of IBC
islands by means of transparent links
provided by PNOs as a publicly available
service, the common teleservices, based on
the common communication platform, will
enable end-users to communicate trans-
nationally without any change in the end
systems or in the underlying network
technology.
Papers/reports: Reports (October 1992):
Broadband Islands and Testbeds within
CIO
Comparison of the Transport Mechanisms
of TP4, TCP and XTP
IWUs and UNIs: Procurement Analysis,
Survey of Existing Systems and
Interfaces and of Systems and Interfaces
Planned by Manufacturers
MMMS: Requirements on a Multimedia Mail
Service
Requirements of Asynchronous
Audio/Data/Video Service on the
Communication Platform
Requirements of Isochronos
Audio/Data/Video Service on the
Communication Platform
Multimedia Communication Platform:
Specification of the Broadband Transport
Service/Protocol
MMMS: Functions and components to be
implemented
JVTOS: Requirements on a Joint Viewing
and Tele-Operation Service
JVTOS (MF): Specification of the Minimal
User Interface and Minimal Functions
(MF) to be implemented in all End
Systems
SMDS and Interworking Aspects
Published papers (October 1992):
"Offene Kommunikation in Europa (Netze,
Protokolle, Datenstrukturen) - Projekte
der Europaischen Gemeinschaften", IIR -
Konferenz 'Open Systems Interconnection',
Koln, November 1991
"Synchronization of Multimedia Data
Streams in Open Distributed Environments",
2nd International Workshop on 'Network and
Operating System Support for Digital Audio
and Video' Heidelberg, November 1991
"The RACE Project CIO", Proceedings of the
IWACA '92 Munich, March 1992
"Esprit Project OSI95 New Transport
Services for High Speed Networking", 3rd
Joint European Networking Conference,
Innsbruck (Computer Networks and ISDN),
May 1992
"Design and Implementation of a Mobile-
Access Systems to X.400-Services", IFIP
WG6.5 Conference on 'Upper Layer
Protocols, Architecture and Applications',
Vancouver, May 1992
"Advanced Multimedia Services in
Communication Networks", Proceedings of
10th Ann. EFOC/LAN '92 Conference Paris,
June 1992
"Comparison of TP4, TCP and XTP - Part 2:
Data Transfer Mechanisms", European
Transactions on Telecommunications,
December 1992
"JVTOS - A Reference Model for a New
Multimedia Service", Submitted to the 4th
IFIP Conference on High Performance
Networking, Liege, December 1992
Contact point: Wulf Bauerfeld (bauerfeld@tz-
berlin.detecon.dbp.de)
DETECON Technisches Zentrum Berlin
Voltastr. 5
D-1000 Berlin 65
Phone: +49 30 46701 310
Fax: +49 30 46701 445
Date of entry: 18 January 1993
Project name: CoMMedia (Co-operation, Communication and
Multimedia)CoMMedia
Funding body: Royal Norwegian Council for Scientific and
Industrial Research
Norwegian Telecom Research
Participants: UNINETT (NO)
University of Oslo (NO)
University of Bergen (NO)
University of Trondheim (NO)
University of Tromso (NO)
Ostfold Regional College (NO)
Norwegian Computing Centre (NO)
SI (NO)
SINTEF (NO)
FORUT (NO)
Timescale: Preliminary phase: June 1992 to March 1994
Main project commences April 1994 for at
least 2 years
Project aims: To develop distributed multimedia
demonstrators.
Description: Multipart Classroom/Meeting Room. This
activity shall develop a prototype for
support of distant education and
distributed meeting rooms. A bilateral
connection is already established between
the University of Oslo and the university
studies at Kjeller (based on the H.261
protocol). A national infrastructure will
be realised to support bilateral and
multilateral communication between the
universities and the other participants in
CoMMedia.
Joint Editing. A joint editing system
will be developed. It will be based on the
Global Window system developed by the
Norwegian Computing Centre.
Multimedia Post. Experiments on
exchanging ODA documents over X.400 have
already taken place. Since ODA still has
limited functionality, development of a
MIME based user agent is planned.
Multimedia Library. There exists several
library and information services providing
access to textual information via computer
networks. CoMMedia aims towards giving
access to images, audio and video
material.
Multimedia Newspapers. Norway is the land
of newspaper readers. CoMMedia will aim
towards giving interactive access to news
via computer networks.
Multimedia Home Office. This activity is
aiming towards giving multimedia support
to small offices and home offices which do
not have high capacity network access.
Standards used: Not yet decided, but may include
H.261, X.400, MIME, DVI, MPEG.
Papers/reports: A Norwegian report "MultiTeam
Infrastructure" exists. A paper has been
submitted to JENC4 (Trondheim 1993).
Contact point: Rune Hjelsvold
(Rune.Hjelsvold@idt.unit.no)
UNINETT multimedia co-ordinator
Date of entry: 18 January 1993
Project name: DARPA Remote ConferencingDARPA Remote
Conferencing
Funding body: Funded by the participants. Research is
co-ordinated by the IETF Remote
Conferencing Working Group. (There is
also a separate Audio/Video Transport
Working Group.)
Participants: Numerous, including:
AT&T (US)
INRIA (FR)
Lawrence Livermore National Laboratory
(US)
LBL (US)
MCNC Centre for Communications (US)
MIT (US)
UCL (GB)
Xerox PARC (US)
Timescale: Commenced March 1992
Project aims: To bring remote conferencing over the
Internet to a reality.
To produce a complete end-to-end open
architecture for remote conferencing on
the Internet.
Description: The remote conferencing architecture is
intended to address both the workstation
and conference room environments and, in
addition to video and audio, will cover
other media commonly used in local
conferencing such as data, text, still
images and CD-ROM.
The architecture will address both
"tightly-controlled" n-to-n conferences
(where n <= about 15) and "loosely-
controlled" 1-to-n conferences (where n <
infinity). It is intended that the
architecture should be capable of
implementation on PC-class machines as
well as powerful workstations.
The work so far has used IP Multicast
extensions. The "vat" audio conferencing
tool and the "nv" and "ivs" video tools
are utilised and refined through this
research. IETF meetings and specialist
workshops have been broadcast on the
Internet using these tools, and the
experience gained with these experiments
is informing debate on the interaction
between remote conferencing traffic and
other traffic on the Internet.
Architecture and protocols for conference
control form an important part of this
research, using tools such as the Session
Directory "sd". All the above-mentioned
tools are documented in the Products
section of this survey.
The target date for a completed basic
remote conferencing architecture is March
1993.
Standards used: H.261, RTP, IP Multicast
Papers/reports: "Charter of the Audio/Video Transport
Working Group", S. Casner, IETF, Santa Fe,
November 1991.
"Charter of Remote Conferencing Working
Group", J. Drescher and A. Ollikainen,
IETF, Boston, 1992.
"Real Time Multimedia Communications
Architecture (Draft)", Y. H. Chang,
November 1992.
Contact point: J. Drescher (drescher@concert.net)
Co-chair, IETF Remote Conferencing Working
Group
MCNC Centre for Communications
3021 Cornwallis Road
Research Triangle Park
NC 27709
USA
A. Ollilkainen (ari@es.net)
Co-chair, IETF Remote Conferencing Working
Group
Lawrence Livermore National Laboratory
Mailing list: rem-conf@es.net
List archive:
nic.es.net:[anonymous.ietf.rem-conf]
There is a separate mailing list for
conference control/management issues:
confctrl@isi.edu.
Date of entry: 13 December 1992
Project name: DEMON (Delivery of Electronic Multimedia
Over the Network)DEMON
Funding body:
Participants: Bellcore (US)
Timescale:
Project aims: To investigate the network requirements of
near-term residential multimedia services.
Description: The project is designing and implementing
an experimental application which serves
the needs of casual multimedia users. To
this end, it is concentrating on three
areas:
Multimedia document delivery at
1.5Mbit/s.
A user interface for casual users.
Interactive authoring of temporal
documents.
Standards used: JPEG, MPEG, H.261
Papers/reports: "Multimedia Communications for
Users", J. Rosenberg et. al., IEEE
Communications, May 1992.
"Presenting Multimedia Documents Over a
Digital Network", J. Rosenberg, G. Cruz
and T. Judd, Computer Communications,
July/August, 1992 (also available in
Proceedings of Second International
Workshop on Network & Operating System
Support for Digital Audio & Video,
November, 1992, Heidelberg, Germany:
Springer-Verlag.)
"A Real-time Publishing Model: Network
Delivery of Multimedia Documents", G. Cruz
et. al., Proceedings of EDD '92: A Vehicle
for Change October 13-15, 1992,
Parsippany, NJ.
"Requirements for Network Delivery of
Stored Interactive Multimedia", D. New et.
al., Proceedings of Third International
Workshop on Network & Operating System
Support for Digital Audio & Video,
November 12-13, 1992, San Diego, CA:
Springer-Verlag.
Contact point: Jonathan Rosenberg
(jxr@thumper.bellcore.com)
Date of entry: 18 January 1993
Project name: EuroBridgeEuroBridge
Funding body: Commission of the European Community
Participants: RWTH Aachen (DE)
Timescale:
Project aims: To find flexible communication structures
for distributed multimedia applications.
Description:
Standards used:
Papers/reports:
Contact point: Wilko Reinhardt (wilko@informatik.rwth-
aachen.de)
Lehrstuhl f. Informatik,
RWTH Aachen,
Ahornstr. 55.
Germany
Fax: +49 241 80 21429
Date of entry: 18 January 1993
Project name: HeiProjectsHeiProjects
Funding body: IBM
Participants: IBM European Networking Centre, Heidelberg
(DE)
Timescale:
Project aims: To develop prototype multimedia system
components that are intended to co-
operate, but can also be used in other
environments.
To investigate the right function set for
potential future IBM products in the area
of multimedia support.
Description: The HeiProjects are (a collection of sub-
projects) aimed at providing a universal
multimedia platform for networked
workstations. This platform shall be used
to support distributed multimedia
applications, eg for collaborative working
support or multimedia mail exchange. Its
core component is a multimedia transport
system that permits the exchange of
multimedia data with end-to-end
performance guarantees over a variety of
underlying networks with different degrees
of multimedia support.
A toolkit which encompasses a set of basic
multimedia services for constructing
distributed multimedia applications is
being designed. Whereas the transport
system is responsible for real-time data
transfer, the toolkit provides service
elements to organise and control
communication.
Examples of services which the
architecture is designed to support
include audiovisual conferencing and video-
on-demand services.
Standards used:
Papers/reports: "The HeiProjects: An Updated Survey",
R. G. Herrtwich, October 1992.
Contact point: Ralf Herrtwich
IBM European Networking Center
Tiergartenstr. 8
D-6900 Heidelberg 1
Germany
Date of entry: 21 January 1993
Project name: ISLE/EVANISLE/EVAN
Funding body: DEC
Heriot-Watt University (GB)
Participants: Heriot-Watt University (GB)
Timescale: Commenced April 1992 for up to 3 years
Project aims: To build an Intensively Supported Learning
Environment.
To identify the technology requirements
for computer-based distance learning.
To identify the characteristics of
learning materials and how these map to
computer multimedia forms.
To determine the place of video and other
conferencing forms in distance learning.
Description: This project is in two sections - ISLE,
which is concerned with investigating
computer-based learning environments from
an education pedagogy viewpoint; and EVAN,
which is concerned with distance learning
issues. EVAN is of more relevance as a
"client" for distributed multimedia
capabilities.
The ISLE project is developing an
interactive multimedia learning
environment, initially based on the NESTOR
multimedia toolkit from the Universities
of Karlsruhe and of Kaiserslautern
(Germany), and targeted on the DECAthena
distributed computing environment (a
distributed UNIX environment) and
eventually for the PC/Windows environment.
The EVAN project concentrates on three
entities: (i) services, (ii) subscribers,
and (iii) access. Services will be
learning based services, provided by
Universities or other institutions
offering distance learning materials to
subscribers such as students. Access is
provided by data and communications
networks. The EVAN project is less
concerned with the underlying transport
mechanism, more with the way in which
multimedia can help distance learning
applications build towards providing a
classroom environment to the remote
student who wishes to learn on an as-
needed basis.
The project is interested in both the
Campus-based student (such as found in
Universities) and the true distance
learning student. The latter may comprise
the bulk of the potential customer base
for distance learning. The geographically-
dispersed character of this customer base
suggests that ISDN, as a potentially
widely available method of network access,
will be a very relevant underlying network
technology.
Standards used:
Papers/reports:
Contact point: Terry Mayes (cbltm@clust.hw)
Heriot-Watt University
Riccarton
Edinburgh
Great Britain
Date of entry: 10 December 1992
Project name: JIPS VideoconferencingJIPS
Videoconferencing
Funding Body: Joint Network Team (GB)
Participants: University College London (GB)
Timescale: 1992
Project aims: To determine the feasibility of
establishing small-scale video
conferencing over the JANET IP Service
(JIPS).
Description: This project involved the transmission of
simulated H.261 video traffic at rates
from 64 kbit/s to 256 kbit/s using UDP
over JIPS, with University College London
as the source and Cambridge as a sink, and
later with Edinburgh as a source and
Cambridge as a sink. The tests measured
the distribution of inter-pocket arrival
times and the packet loss rate.
Further work is planned using real video
signals encoded with H.261.
Standards used: H.261
Papers/reports: "A Short Summary of the Initial
Results Obtained on px64 kbit/s Data
Transmission over JIPS", S. Hailes, UCL.
Contact point: Jon Crowcroft (J.Crowcroft@cs.ucl.ac.uk)
Department of Computer Science
University College London
London
Great Britain
Date of Entry: 1 December 1992
Project name: JITOL (Just In Time Open Learning)JITOL
Funding Body: DELTA programme (Commission of the
European Community)
Participants: Logica (UK)
DEC(GB)
DEC (FR)
Lancaster University (CSALT, CSET and
Comp. Sci.) (GB)
NeuropeLab (project managers) (FR)
Norwegian Ministry Of Education (NO)
RIKS (NL)
University of Trondheim (NO)
University of Geneva (CH)
University of Lisbon (PT)
Timescale: 3 years
Project aims:
Description: The project is a study of a novel
collaborative learning technique called
just-in-time open learning. The main
feature of this is that the learner works
with peers to acquire knowledge from
learning resources such as MM documents,
courses and experts. The resource base is
expected to be modified by the learners
and to evolve into more useful forms. The
JITOL project will look at supporting
jitol over wide area networks spread
across several European countries. There
will be large-scale user trials in three
subject domains: commerce, education and
medicine; as well as a number of small-
scale trials.
Standards used:
Papers/reports:
Contact point: Graham Storrs (ges@logcam.co.uk)
Date of Entry: 18 January 1993
Project name: Libernet.91Libernet.91
Funding body: Pacific Bell (US)
Participants: Pacific Bell (US)
Timescale: Commenced 1990
Project aims: To develop a prototype library of
multimedia books.
Description: The Libernet.91 system provides a network
of Apple Macintosh computers with access
to a library of multimedia books. Audio
and video is carried over separate wiring
controlled by an analog switch. The
development focused on solving problems
using existing tools where possible -
using the Aldus SuperCard object-oriented
database, for example.
The system software consists of four
programs:
Libernet.91 is the front end to the
system for readers.
MMcataloger maintains the database
describing the books, and provides a
user interface for use by the librarian.
MediaServer is responsible for setting
up access to a multimedia book in
response to a user's request (for
instance by reserving access to a
particular media device).
MediaSwitcher controls the audio/video
switch which delivers output to the
reader's desk.
The project was initiated in the spirit of
"scruffy science" - concentrating on
getting a working system going in minimal
time. Future work will concentrate on:
Extra facilities for readers
("bookmarks", "bookshelves", intelligent
library search processes).
Use of UNIX as a platform for the server
processes.
Providing user interfaces for other
platforms.
Finding ways to optimise user queries
and handle structure changes.
Addressing issues such as scale up, user
authentication and access authorisation.
Standards used:
Papers/reports: "Accessing Multimedia Network
Services", K. H. Smith Jr., IEEE
Communications Magazine, p72, May 1992
Contact point:
Date of entry: 25 January 1993
Project name: MADE (Multimedia Application Demonstration
Environment)MADE
Funding body: British Telecom plc (GB)
Participants: BT Research Laboratories (GB)
University of Kent (GB)
Timescale:
Project aims: To demonstrate the value of multimedia
communications to both BT and their
customers.
Description: This project centres on the use of MHEG to
access a multimedia object server. The
platform for the server is a Sun
SPARCstation with an object-oriented
database package (ONTOS). Audio, video,
text and graphical data types are covered.
Kent University is working on a sub-
project: "Multi-user Indexing in a
Distributed Multimedia Database".
Standards used: MHEG, JPEG, JBIG, MPEG
Papers/reports:
Contact point: Darryl Morgan
BT Research Laboratories
Martlesham Heath
Ipswitch
IP5 7RE
Great Britain
Phone: +44 473 643396
Date of entry: 22 December 1992
Project Name: MCRL (Multimedia Communications Research
Lab)MCRL
Funding Bodies: Telecommunications Research Institute
of Ontario (CA)
Canadian Institute for Telecommunications
Research (CA)
Natural Sciences and Engineering Research
Council (CA)
Participants: BNR
Northern Telecom
Bell Canada
Telesat Canada
Timescale: Commenced 1984
IRIS project: 1988 to 1991 (Multimedia
Radiology Information System)
MEDIABASE project 1989 to 1995
Project aims: To develop test beds for Multimedia
applications.
To develop and study the performance of
Multimedia Distributed Information
Systems.
Description: MCRLab, located at the University of
Ottawa, is comprised of three co-operating
research teams focused on the transport,
coding and implementation of Multimedia
Communications for Co-operative Work. Each
team is identified in a short summary of
research activities below.
The Networks, Protocols and Performance
group focuses its research efforts on
multimedia broadband communications and
high speed network protocols. This group
examines network performance, congestion,
conferencing and message synchronisation.
In the area of synchronisation, efforts
have been focused on simultaneous real-
time data delivery and temporal
presentation control.
The Image and Video Coding and Processing
group examines issues related to
progressive image transmission and is
involved in the design and development of
algorithms and architectures for video
compression.
The Multimedia Database and Distributed
Systems Group focuses its research efforts
on the development of a multimedia real-
time distributed information system.
MEDIABASE is a project on multimedia
information systems with particular focus
on document architecture, database models,
high level communication protocols,
distributed object-oriented environments
and physical storage of multimedia
information. The MEDIABASE project
consists of the following sub-projects:
Temporal Synchronization of Multimedia
Documents (MEDIADOC)
A Data Model for Temporal Multimedia
Databases (MEDIAMODEL)
A Persistent Multimedia Object-oriented
Storage System (MEDIASTORE)
Integrated Physical Storage of
Multimedia Objects with Temporal
Constraints (MEDIAFILE)
A Distributed Architecture for
Multimedia Applications (MEDIASYSTEM)
High Level Multimedia Communication
Protocols (MEDIACOM)
A Multimedia Information System Platform
(MEDIAPLATFORM)
The three groups collaborate in the
development of large multimedia
applications. Past projects have focused
on distributed multimedia medical imaging
applications. Present efforts are focused
on a distributed multimedia real estate
application.
Standards Used: MIME, MPEG, JPEG, ODA, H.261, X.400
Papers/reports: "Multimedia Communications Research
Laboratory, Report of Activities: 1991 -
1992"
Contact Point: Nicolas Georganas
(nngpb@acadvm1.uottawa.ca)
Multimedia Communications Research
Laboratory (MCRL)
Faculty of Engineering, University of
Ottawa
Ottawa
Ontario
K1N-6N5
Canada
Phone: +1 613 564 8222
Fax: +1 613 564 7681
Date of entry: 18 January 1993
Project name: MIASMIAS
Funding body: Esprit (Commission of the European
Community)
Participants: Alcatel (FR)
Amper (ES)
BT Research Laboratories (GB)
CNET (FR)
CSELT (IT)
PTT Research (NL)
Telefonica (ES)
Timescale: Commenced February 1989
Project aims: To study the necessary features and
protocols needed for multipoint multimedia
communication.
Description: A Multipoint Interactive audiovisual
System (MIAS) was developed. The system's
audiovisual terminal consists of
specialised hardware attached to an ISDN
line (2B+D channels) incorporating a video
input connector and H.261 codec, and a
G.722 codec and associated audio I/O
circuitry. Video display is in a window
on a PC (running MS Windows). The PC is
also used for conference control and for
file transfer.
Lap B is used over H.221 for the lower
layers.
Standards used: G.722, H.261, H.221.
Papers/reports: "Multipoint Multimedia Conferencing",
W. J. Clark, IEEE Communications Magazine,
p44, May 1992.
Contact point: William J. Clark
Multipoint Teleconferencing Group
BT Research Laboratories
Martlesham Heath
Ipswitch
IP5 7RE
Great Britain
Date of entry: 25 January 1993
Project name: MICE (Multimedia International
Conferencing for European Researchers)MICE
Funding body: Esprit programme (Commission of the
European Community)
Participants: GMD
INRIA (FR)
Nottingham University (GB)
NTR
ONERA
SICS (SE)
Stuttgart University (DE)
ULB/VUB
University College London (prime
contractor) (GB)
University of Oslo (NO)
Timescale: Commenced December 1992
Project aims: To provide appropriate multimedia, multi-
party conferencing facilities to research
workers in Europe, with links to North
America; these to be provided across
disciplines and ideally, usable by any
research worker.
To design these facilities to interwork
with those already deployed for other
projects in the research community.
To provide the facilities in a form that
would be appropriate to complement multi-
party meetings so that one emphasis will
be on conference rooms; workstations with
reduced facilities will also be embraced.
In both cases the facilities provided will
include shared workspace use of
workstations as well as video-
conferencing.
To design the facilities to be deployable
with minimal expenditure on communications
and minimal delay, thus precluding the
provision of a separate communications
network.
To use the emerging European
infrastructure of international
connections between National Packet
Switched Networks (Europanet and EBONE
inside Europe, and the different links to
the US from Europe)
Description: The project is planned for completion in
12 months. It will consist of three
overlapping phases: definition, trials and
evaluation. During the definition phase, a
multimedia conferencing reference
architecture will be defined; thereafter
the exact facilities to be provided in
conferencing rooms, conferencing
workstations and a Conference Multiplexing
and Management Centre will be specified.
During the trials phase, the facilities of
all three areas will be improved
progressively and put into limited
service. During the evaluation phase, the
strengths and weaknesses of the facilities
will be assessed, forecasts will be made
on the timing of more economic equipment
and more appropriate algorithms, and
recommendations will be made for the
deployment of an operational system. The
timescale is only achievable, within the
limited effort proposed, because the
project will be based heavily on existing
developments funded under other
programmes.
It is intended that the four initial
sites should be connected within the first
four months of the project.
Standards used:
Papers/reports:
Contact point: Jon Crowcroft (J.Crowcroft@cs.ucl.ac.uk)
Department of Computer Science
University College London
London
Great Britain
Date of entry: 21 December 1992
Project name: MNIMNI
Funding body: SERC (GB)
BT Research Laboratories (GB)
Participants: University of Lancaster (GB)
Timescale: Commenced August 1989
Project aims: To design an experimental multimedia
network interface based on transputers.
To experiment with integrated channel
methods, and communications services and
protocols for multimedia traffic.
To develop a model of an integrated
channel interface between a multimedia
workstation and a multi-service network,
compatible with OSI and ODP.
Description: A survey of existing ISO protocols has
been carried out, and a number of
additional multimedia requirements have
been identified. A basic transputer based
network switch has been developed and
implemented and a prototype multimedia
workstation with a transputer based
enhancement unit has been built. A
dynamically reconfigurable transport layer
protocol which meets the additional
requirements of multimedia data has been
designed. An initial implementation of
this protocol to run on the transputer
based prototype multimedia workstations is
currently under test.
The first implementation of a network
protocol emulator has also been completed
and tests are being carried out to verify
its accuracy. This first emulation is of
a FDDI network. Additionally, work has
begun on the development of a transputer
based storage server for stream data.
This storage server will provide services
to the prototype multimedia workstations
via the network protocol emulator, using
the transport protocol developed.
Standards used:
Papers/reports:
Contact point: The Distributed Multimedia Research Group
Computing Department
Lancaster University
Bailrigg
Lancaster LA1 4YR
Great Britain
Date of entry: 21 December 1992
Project name: MOST (Mobile Open Systems Technologies for
the Utilities Industries)MOST
Funding body: SERC/DTI ODSA programme (GB)
Participants: University of Lancaster (GB)
EA Technology, Chester (GB)
Timescale:
Project aims:
Description: MOST is a two year project focusing on the
application of Open Distributed Processing
in the utilities industries. One of the
key features of the utilities industries
is the need to access a wide range of
information in the field. However, this
introduces a number of technical
challenges for ODP:
the impact of mobile communications;
integrated access to information
services;
the need to support multimedia
information.
The MOST project will address these
technical issues and will develop an ODP-
based distributed systems platform, which
integrates mobile communications, a range
of information services (including a
Geographic Information System) and
multimedia capabilities.
Standards used:
Papers/reports:
Contact point: The Distributed Multimedia Research Group
Computing Department
Lancaster University
Bailrigg
Lancaster LA1 4YR
Great Britain
Date of entry: 18 January 1993
Project name: Multi GMulti G
Funding Body:
Participants: Swedish Institute of Computer Science
(SICS) (SE)
Royal Institute of Technology (KTH) (SE)
Ellemtel Development Company (SE)
Swedish Telecom (SE)
Timescale: 1990 to 1993
Project aims: To strengthen academic infrastructure.
To increase competitive strength of
industry.
To integrate SICS and KTH research
environments.
To demonstrate gigabit networking.
To demonstrate gigabit applications.
Description: One of the activities is investigating the
use of ST-2 over ATM. SICS have
successfully demonstrated ST-2 over ATM
between two workstations with ATM
interfaces directly connected. They have
written their own ST-2 implementation
(about 6500 lines of C code in the UNIX
kernel).
Standards used: ST-2
Papers/reports: "An Implementation of the Revised
Internet Stream Protocol (ST-2)", C.
Partridge and S. Pink, Journal of
Internetworking: Research and Experience,
March 1992.
Contact point: Stephen Pink (steve@sics.se)
Distributed Systems Lab
Swedish Institute of Computer Science
Date of Entry: 1 December 1992
Project name: Multimedia RPCMultimedia RPC
Funding body:
Participants:
Timescale: Commenced April 1991
Project aims: To extend the design of remote procedure
call protocols to encompass real time,
multimedia transmissions.
To implement the extended RPC on a pre-
existing multimedia distributed system
consisting of a high speed network
emulator and multimedia workstations.
To provide input to the various standards
bodies (particularly ODP) with regard to
multimedia RPC engineering support for
object based computational models.
Description: Formal title: "Engineering Support for
Remote Procedure Calls in Multimedia
Environments"
The first deliverable from this project is
now complete. This comprises a survey of
RPCs and RPC-like mechanisms, with input
from current and past research on remote
procedure calls (RPCs), RPC-like
mechanisms, distributed operating systems,
bulk data transfer, multimedia
communication requirements and transport
protocols. The suitability of RPCs for
multimedia communications is now being
assessed, and a number of recommendations
are being prepared. Based on these
recommendations it is hoped to build and
evaluate a prototype multimedia RPC.
Standards used:
Papers/reports:
Contact point: The Distributed Multimedia Research Group
Computing Department
Lancaster University
Bailrigg
Lancaster LA1 4YR
Great Britain
Date of entry: 21 December 1992
Project name: MUMSMUMS
Funding body:
Participants: LUTCHI Research Centre, Loughborough
University (GB)
Queen Mary and Westfield College, London
(GB)
Timescale: January 1990 to December 1993
Project aims: To develop an application framework to
support the development of group-working
applications.
To develop a group-working and a
multimedia interaction model.
Description: MUMS is taking a user-centred approach to
group-working. An application framework
is under development, which is informed by
a model of group-working and a model of
multimedia interaction. The application
framework will provide a software
infrastructure to assist in the
construction of group-working
applications. The framework will implement
an architecture developed from a User
Interface Management System and extended
for group-working as advised by the
models. The group-working model will take
into account the way users interact with
each other as well as with the task at
hand. The multimedia interaction model
will examine the use of different media to
represent appropriate information to
different users and to the group. The
models will support the construction of
group-working applications. The
application domain of Spatial Planning, eg
Architecture and Urban Planning, has been
selected for the construction of a series
of prototypes.
Macintosh and Sun SPARC workstations are
used as the hardware base for this work.
Standards used: QuickTime
Papers/reports: "Negotiation Support in Design", E.
A. Edmonds and R. M. Jones, Gero &
Sudweeks (editors), Preprints of
Artificial Intelligence in Design Workshop
of IJCAI '91, University of Sydney, p93,
1991.
"An Analysis of Media Integration for
Spatial Planning Environments", N. E.
Branki, R. M. Jones and E. A. Edmonds,
Timmermans (editor). Proc. Design &
Decision Support Systems in Architecture
and Urban Planning Conference. Eindhoven,
July 1992.
"A Framework for Negotiation", R. M. Jones
and E. A. Edmonds, Connolly & Edmonds
(editors). Proc. CSCW, AI and Autonomous
Agents, London, June 1992.
Contact point: Rachel Jones (R.M.Jones@uk.ac.lut)
David Bell (bell@dcs.qmw.ac.uk)
Date of entry: 18 January 1993
Project name: OSI 95OSI 95
Funding Body: Esprit programme (Commission of the
European Community)
Participants: Alcatel-Bell-Telephone (BE)
Alcatel-Austria-Elin (AT)
Bull SA (FR)
Institut National des Telecommunications
(FR)
Intracom SA (GR)
INRIA (FR)
Lancaster University (GB)
Olivetti Research Ltd (GB)
Universite de Liege (BE)
Universidad Politecnica de Madrid (ES)
Timescale: November 1990 to 1995
Project aims: To design, specify and verify a transport
and internet protocol (TPX) which will not
jeopardise the potential bandwidth offered
by the new environments created by HSLANs
as well as by the MANs and soon by the
broadband ISDN based on ATM.
To integrate high-speed MAN and WAN into
the OSI reference model and to revise the
OSI protocols of layers 3 to 7, in order
to offer adequate high-performance
services up to the application layer.
To define requirements of the associated
computing environment with respect to
multimedia, new distributed systems, and
ODP.
Description: Full title of project: "High Performance
OSI Protocols with Multimedia Support on
HSLANs and B-ISDN".
OSI 95 intends to revisit the OSI
Reference Model from layer 2 up to the
application level with one objective: the
design of high-performance protocols for
the new communication and application
environments. The main effort will be
invested in the design, formal
specification and validation of a high
performance protocol TPX, based on the
standard LLC type 1 service and offering
the standard transport connection mode.
The project will introduce and support
this protocol in various standardisation
bodies.
Above the transport layer, the objective
of the project is the study of the
evolving computing environment in order to
define more adequate application and
transport services. Three elements of this
environment have been identified:
multimedia, new distributed systems and
ODP. The effects of new applications which
require the handling of multimedia
objects, and the difficulties of
supporting new distributed systems such as
Esprit's COMANDOS will be studied in
detail. In addition, an investigation will
be conducted to ensure that duplication of
functions such as location and replication
transparency does not take place between
the SE-ODP and the communication systems.
Standards used:
Papers/reports:
Contact point: The Distributed Multimedia Research Group
Computing Department
Lancaster University
Bailrigg
Lancaster
LA1 4YR
Great Britain
Date of Entry: 16 December 1992
Project name: PACT (Packet-switched Adaptive Compressed
Transmission of Images)PACT
Funding Body: SERC (GB)
Participants: University College London (GB)
Timescale:
Project aims:
Description: PACT is looking at ways to use adaptive
codecs for video (and audio) to adjust the
compression parameters to adapt to
conditions in the network. It is based on
the use of a rate control algorithm to
control admission and congestion in the
network. This work is being carried out in
collaboration with a major workstation
manufacturer.
Standards used:
Papers/reports:
Contact point: Jon Crowcroft (J.Crowcroft@cs.ucl.ac.uk)
Department of Computer Science
University College London
London
Great Britain
Date of Entry: 18 January 1993
Project name: PalantirPalantir
Funding Body:
Participants: University of Kent (GB)
Rutherford Appleton Laboratory (GB)
Timescale:
Project aims: To investigate the problems of modelling
multimedia systems involving a range of
technologies and qualities of service.
To test the suitability of the ISO
Reference model for Open Distributed
Processing as a basis for such systems.
To identify new requirements arising from
new styles of multimedia application,
particularly involving synchronisation of
media.
To develop an application environment and
assess the ease of remote access to it.
Description: ISDN is used to link LANs at the two sites
(KENT & RAL), with a "Model ATM Exchange"
(MATMX), which manages n x 64 kbit/s
channels to provide a single variable-rate
data path. A video capture device is
attached directly to the MATMX.
Video display in a workstation window is
achieved by gating the video feed to a
workstation display with the video signal
transmitted from the remote video source.
Special-purpose PC-controlled hardware is
used for this purpose.
Standards used:
Papers/reports:
Contact point: Peter F. Linington (pfl@uka.ac.uk)
Computing Laboratory
University of Kent at Canterbury
Canterbury
Kent
CT2 7NF
Great Britain
Phone: +44 227 764000
Date of entry: 18 January 1993
Project name: PegasusPegasus
Funding body: Esprit (CEC)
Participants: University of Twente (NL)
University of Cambridge (GB)
Timescale: September 1992 to September 1996
Project aims: To design and build a distributed storage
service that can work on a world-wide
scale, that provides arbitrarily high
levels of reliability and availability,
and that is capable of storing multimedia
documents including digital video in real
time.
To design and build the multimedia
infrastructure that will allow such
activities as video conferencing,
multimedia document exchanges, multimedia
communication, etc.
To design and build a demonstration
application.
Description: Pegasus is a project aimed at the design
of an operating systems architecture for
scalable distributed multimedia systems.
Distributed systems, multimedia, and
developments in processor and memory
technology are changing the way in which
systems should be designed to such an
extent that the systems technology in
common use at university and in industry
today is rapidly becoming inadequate. If
one wishes to incorporate full-speed and
high-quality digital audio and video in a
distributed system, building one from the
ground up is a necessity, because there
are no systems around with sufficient
support for high-performance, low-overhead
soft real time.
The project team will design and build a
prototype of the sort of system expected
to be common in research environments by
the year 2000. The primary goal of the
project is "to do it right": to build a
true distributed multimedia system that
can scale to millions of nodes. Project
activities include:
Development of a validating prototype.
Design and implementation of a
distributed complex-object service and a
global name service.
Design of mechanisms for the creation,
communication, and rendering of fully
digital multimedia documents in real
time and in a distributed fashion (with
support for full-screen digital motion
video and digital hi-fi stereophonic
sound).
Design and implementation of an
application for the system - a digital
TV director.
Standards used:
Papers/reports: The Pegasus Technical Reports (and
the list of currently available reports)
can be obtained from University of Twente,
address below.
Contact point: Sape J. Mullender
(mullender@cs.utwente.nl)
University of Twente
Faculty of Computer Science / SPA
P.O. Box 217
7500 AE Enschede
The Netherlands
Phone: +31 53 893 709
Fax: +31 53 309 723
Date of entry: 21 December 1992
Project name: PlateauPlateau
Funding body: Fujitsu, Hewlett-Packard, others
Participants: University of California, Berkeley (US)
Timescale: Commenced May 1992
Project aims: To develop a distributed multimedia
toolkit and applications.
Description: Plateau is a research group rather than a
single project.
The paper mentioned below describes an
application built using a toolkit
architecture that provides for best-effort
delivery of multimedia data over
conventional LANs using UDP. The network
support is being extended to include RTIP,
a real time network being developed at UC
Berkeley by Domenico Ferrari (see Tenet
entry in this survey).
The group has also developed and released
a public domain MPEG decoder, and are
developing a public domain MPEG encoder.
These will be added to the application
architecture described below.
Standards used: JPEG, MPEG
Papers/reports: "A Continuous Media Player", L. A.
Rowe and B. C. Smith, Proceedings of the
Third International Workshop on Network
and Operating System Support for Digital
Audio and Video, San Diego, November 1992.
Also available via FTP from
toe.cs.berkeley.edu:/pub/multimedia.
Contact point: Larry Rowe (Rowe@cs.berkeley.edu)
Brian Smith (bsmith@cs.berkeley.edu)
Date of entry: 18 January 1993
Project name: QOS-A (A Quality of Service Architecture
for Multimedia Communications Systems)QOS-
A
Funding body: SERC (GB)
Netcomm Ltd (GB)
Participants: University of Lancaster (GB)
Timescale:
Project aims: To define a QOS Architecture that
reconciles the User-oriented QOS
requirements with the Network-oriented QOS
environment for distributed multimedia
applications.
To integrate this QOS-A into multi-service
communications networks, in particular
those based on ATM technology, in the
context of a local ATM network that is
being developed at Lancaster.
To demonstrate the applicability of the
architecture in a small number of
interactive real-time distributed
multimedia application scenarios.
To introduce the results of the work into
the Open Systems standardisation process
(specifically the ISO New Work Item on
QOS).
Description: This project will develop a Quality of
Service Architecture (QOS-A), encompassing
communications and distributed systems
support, in which QOS guarantees may be
provided for interactive continuous media
applications operating over multi-service
networks. The QOS-A will provide
integrated resource control, monitoring
and regulation strategies necessary for
the support of continuous media in
broadband packet networks.
Standards used:
Papers/reports:
Contact point: The Distributed Multimedia Research Group
Computing Department
Lancaster University
Bailrigg
Lancaster
LA1 4YR
Great Britain
Date of entry: 18 January 1993
Project name: RapportRapport
Funding body:
Participants: AT&T
Timescale:
Project aims:
Description: The Rapport multimedia conferencing system
allows people to hold real-time
discussions in which they share voice,
video and program displays. It implements
a "meeting room" metaphor, and is based on
UNIX workstations. Rapport can manage
calls with a mix of devices, including
both computers and telephones. Rapport
supports colour video conferencing.
Standards used:
Papers/reports: "Co-ordination and Control of
Multimedia Conferencing", S. R. Ahuja and
J. R. Esnor, IEEE Communications Magazine,
p38, May 1992.
Contact point:
Date of entry: 25 January 1993
Project name: SUMO (Support for Multimedia in Open
Distributed Processing)SUMO
Funding body: University of Lancaster (GB)
Participants: University of Lancaster (GB)
Timescale:
Project aims: To develop enhanced and integrated
computational and engineering models to
support multimedia, particularly
continuous media such as digital video and
audio, in an Open Distributed Processing
environment.
Description: The models will be verified by a prototype
implementation based on the Chorus micro-
kernel. The essence of the research is to
support both Quality of Service (QOS)
guarantees and real-time synchronisation
as required by distributed multimedia
applications. The research is also
expected to contribute to the on-going
developments of micro-kernel based
architectures in the areas of real-time
processing and multimedia support.
Standards used:
Papers/reports:
Contact point: The Distributed Multimedia Research Group
Computing Department
Lancaster University
Bailrigg
Lancaster
LA1 4YR
Great Britain
Date of entry: 18 January 1993
Project name: TEMPOTEMPO
Funding body:
Participants: University of Lancaster (GB)
BT Research Laboratories (GB)
Hewlett-Packard Laboratories (GB)
Timescale: Commenced October 1990
Project aims: To investigate the use of formal
specification techniques (specifically
LOTOS and LOTOS extensions) in the area of
distributed multimedia systems
architectures.
To consider techniques for the
verification of real time properties of
such systems.
To provide input into Open Distributed
Processing (ODP) standards activities.
Description: Formal title: "Formal Support for the
Specification and Construction of
Distributed Multimedia Systems".
The TEMPO project is currently conducting
a comparison of different timed formal
description techniques, concentrating on
timed extensions to LOTOS. These
techniques are being evaluated for their
suitability for specifying distributed
multimedia systems. To enable this type of
evaluation the project is looking closely
at the requirements on models of time
needed to specify such systems.
To allow validation of LOTOS
specifications, the group have installed
three toolkits: HIPPO, CAESAR/ALDEBARAN
and TOPO. Both HIPPO and
CAESAR/ALDEBARAN are regularly used in the
development of specifications. However,
if a timed extension to LOTOS is used,
these toolkits will no longer be able to
be used for validation. Alternative
toolkits which can be used for specific
timed extensions to LOTOS are being
investigated.
Standards used:
Papers/reports:
Contact point: The Distributed Multimedia Research Group
Computing Department
Lancaster University
Bailrigg
Lancaster
LA1 4YR
Great Britain
Date of entry: 21 December 1992
Project name: TenetTenet
Funding body: DARPA
NSF
DOE
CNRI
AT&T
DEC
Hitachi
Pacific Bell
University of California
International Computer Science Institute.
Participants: University of California at Berkeley (US)
International Computer Science Institute
(US)
Timescale: Commenced 1988
Project aims: To design communication services for real-
time (and in particular multimedia)
applications.
Description: The Tenet group is a group of researchers
engaged in several projects in the area of
real-time communication. The Tenet
approach to multimedia networking embodies
several principles:
The interface offered by the network
should be general, in that separate
network-layer protocols should not be
necessary for voice, video, etc. An
application should be able to request a
level of network performance appropriate
to its requirements.
The solution should be applicable to a
wide range of internetworking
environments.
Multimedia network applications require
guaranteed performance from the network.
Performance (quality of service)
parameters include bandwidth (in terms
of maximum packet size and inter-packet
arrival time), delay bounds, jitter
bounds, and reliability bounds. These
bounds may be statistical in nature.
Because network performance cannot be
achieved in the face of unpredictable
network application behaviour, the
interface between the network and the
application is modelled as a contract to
which both sides must adhere. The
application guarantees not to exceed the
requested bandwidth for transmission, and
the network guarantees the requested
performance. Achieving this requires a
connection-oriented approach, with a
resource-reservation algorithm employed in
network switches and gateways.
The Tenet group has produced a suite of
protocols ("Suite 1") based on the above
approach. Four protocols are defined:
RCAP (Real-time Channel Administration
Protocol) performs the channel setup
function. It makes use of the
performance parameters requested by the
application to set up a suitable
connection through the internetwork.
RTIP (Real Time Internet Protocol)
performs the data transfer across the
internet. It runs over a Data Link
Layer over (eg) FDDI or ATM.
RMTP (Real-time Message Transport
Protocol) is a Transport-layer protocol
intended for message-based real-time
transport between end points.
CMTP (Continuous Media Transport
Protocol) is a transport protocol
offering a stream interface and a time-
driven mechanism for applications like
video and audio.
Future work ("Suite 2") will incorporate
multicasting for conferencing
applications.
Standards used:
Papers/reports: "Network Support for Multimedia - A
Discussion of the Tenet Approach", D.
Ferrari et. al., Tech.Rept.TR-92-072,
International Computer Science Institute,
November 1992.
This and many other papers can be obtained
via anonymous FTP to tenet.berkeley.edu or
by sending e-mail to file-
server@tenet.berkeley.edu with the words
"index Papers" in the subject field
Contact point: Domenico Ferrari
(ferrari@tenet.berkeley.edu)
Computer Science Division
EECS Department
University of California at Berkeley
Berkeley
CA 94720
USA
Date of entry: 16 December 1992
Project name: TMPI (Theories of Multi-Party
Interaction)TMPI
Funding body: British Telecom (GB)
Participants: Queen Mary and Westfield College (GB)
University of Surrey (GB)
Timescale: December 1989 to November 1992
Project aims: To investigate multimedia real-time
support for distributed groupwork.
Description: A Multimedia Environment for Everyday
Tasks (MEET) is being constructed by the
TMPI project. The aim is to support a
range of social and task-oriented
interactions within the everyday work
environment.
The goals for the system are the
following:
the system should present a flexible
environment for different modes of user
co-operation
the media space should become an
integral part of the normal environment
and reflect the characteristics of
users' working lives
it should be easy and convenient to use
MEET consists of three distinct
components: an audio/video switched
analogue network; a distributed software
architecture to control A/V connections,
and present high-level services to the
user; a groupware system to support
activities such as shared authoring,
design, and information-sharing.
Desktop A/V equipment has been set up
around Sun workstations in four work
areas in the department of Computer
Science at QMW, and is being used by
researchers and programmers for tasks such
as co-operative software porting, and
document development. To date, three
types of connections to remote offices
have been built - a group multimedia
conference (with integrated access to CSCW
tools while conferencing), videophone (A/V
between 2 people), and a Glance facility.
These services are accessed from users'
workstations via an integrated X-based
interface. An API is available for
multimedia application development.
The layered architecture for setting up
A/V connections should facilitate a later
switch to digital technology.
Standards used:
Papers/reports: "Early Experiences in Desktop
Multimedia Conferencing", S. Wilbur, S. R.
Wilbur and S. Ing, to be published in
Computer Supported Collaborative Work, by
Gower, March 1993.
"A Multimedia System for Flexible Co-
operation", S. Wilbur, B. Hewitt and S.
Ing, Supercomm/ICC '92, Chicago, June
1992.
Contact point: Sylvia Wilbur (sylvia@dcs.qmw.ac.uk)
Date of entry: 18 January 1993
Project name: Touring MachineTouring Machine
Funding body: Bellcore
NSF
Participants: Bellcore
Timescale: Commenced 1990
Project aims: To explore the role of public
communications networks in facilitating
future multimedia applications.
To design and realise a robust software
control infrastructure that enables a
broad class of multimedia communications
applications.
To investigate multimedia real-time
support for distributed groupwork.
Description: The research focuses on the design and
realisation of a robust software control
infrastructure that enables a broad class
of multimedia communications applications
by:
providing abstractions to shield the
application designer from the
complexities of routing, resource
allocation, session control, network
management, and presentation control
providing useful services such as access
to directories containing both static
and dynamic state information,
negotiation and security.
The project is heavily experimental in
nature.
The current system provides an API to
application designers; the API defines the
set of messages passed between user
applications and the Touring Machine
infrastructure. The Touring Machine
software is structured as a set of
distributed objects working co-operatively
to provide the services supported by the
API. The system controls desk-top audio
and video devices connected through a
network of multiple switches and other
specialised hardware resources, such as
audio and video bridges and mixers.
Currently, the Touring Machine platform is
the basis of several communication tools,
including CRUISER (TM) and shared data
applications based on RENDEZVOUS (TM).
The CRUISER service is a multimedia
communications application designed to
support informal communications among
remotely located co-workers through the
medium of an audio and video network.
Using Cruiser, people can initiate and
participate in multimedia conferencing
from their desktops, attend seminars
through a "virtual auditorium" service,
and access a variety of other useful
services. The RENDEZVOUS system is an
architecture for creating synchronous
multi-user applications, such as a multi-
user whiteboard. The Touring Machine
platform also supports mobile users, using
active badges from Olivetti Research Labs,
Cambridge. These badges are based on
infrared technology that allows
pinpointing the location of users to
within an office in the building.
The current version of the Touring Machine
prototype uses analog audio and video;
while unsophisticated in terms of
transport technology, this choice allows
the support of a large and active user
population (about 150 users across two
Bellcore locations 50 miles apart
connected by digital links) and allows
effort to be concentrated on developing
the software infrastructure and multimedia
applications. The infrastructure and
applications are implemented by about
200,000 lines of code. The Bellcore
experiment has been operational since
March 1992. The software has also been
distributed to some external sites as part
of research collaborations, including MIT,
University of Michigan, ISI and the DARPA
headquarters, and is part of an NSF funded
project on collaborative visualisation.
Experience with design, implementation and
operation of the current system is driving
the evolution of the system. The next
iteration of system design addresses
system structuring principles for
extensible, open, managed systems, as well
as expanding the functionality of the API.
The design borrows heavily from the
architectural principles of Bellcore's INA
project; the system is designed as a
distributed object-oriented system based
on trading. Research contributions are in
the areas of reliability, extensibility,
support for hybrid analog/digital fabrics,
interworking across multiple
administrative domains, safeguards for an
"enterprise model" allowing third-party
service providers, and integrated systems
management, including fault management and
accounting. The design, based on OSF DCE,
is scheduled to be completed by the end of
January 1993, and a working demo is
planned for 4Q93. There are also plans to
create a version of the current system
accessible via ISDN. The next system
design uses OSF/DCE, OSI CMIP/CMIS, X.500,
ISDN Q.931, and H.261.
Standards used: H.261
Papers/reports: "The Touring Machine System", Arango
et. al., CACM January 1993.
"Touring Machine: A Software Platform for
Distributed Multimedia Applications",
Arango et. al., 1992 IFIP International
Conference on Upper Layer Protocols,
Architectures and Applications, Vancouver,
May 1992.
` "The Touring Machine Project: Toward a
Public Network Platform for Multimedia
Applications", G. Gopal, G. Herman and M.
P. Vecchi, Eighth International Conference
on Software Engineering for
Telecommunications Systems and Services
Florence, March 1992.
"Touring Machine: A Software
Infrastructure to Support Multimedia
Communications", (Extended Abstract),
Arango et. al., MULTIMEDIA '92, 4th IEEE
COMSOC International Workshop on
Multimedia Communications, Monterey, April
1-4, 1992.
Contact point: Gita Gopal (gita@bellcore.com)
Bellcore MRE 2A233
445 South Street
Morristown
NJ 07962
USA
Phone: +1 201 829 4517
Fax: +1 201 829 5889
Date of entry: 19 January 1993
Project name: XMovieXMovie
Funding body:
Participants: University of Mannheim (DE)
Timescale: Commenced 1991
Project aims: To implement the transmission and
presentation of digital movies under X
Description: The XMovie system is a distributed test
bed for integrated transmission and
presentation of digital movies. It
consists of interconnected UNIX
workstations. In the first
implementation, the network was standard
Ethernet. An FDDI-ring has been installed
recently, and XMovie has been ported to
FDDI.
The main components of XMovie are the
Movie Server, the Movie Client and the X
client. These three components can run on
one, two or three different UNIX systems
depending on the requirements of the
application.
The movie server maintains a movie
directory, and is able to store and replay
sequences of digital images (digital
films). On request from the movie client,
a sequence of images is sent over the
network to the movie client. The
transmission protocol is called MTP (Movie
Transmission Protocol), and was developed
specifically for this purpose. The Movie
Client is an extension of the standard X
server of the X Window System. The
extension implements a new set of
functions for the purpose of displaying
movies in a window on the screen.
Examples of new functions are XMOpenMovie,
XMPlayMovie, and XMShowSinglePicture.
These extensions have been integrated into
the source code of the X Window System.
The third component of the system is the X
client. The set of new functions
mentioned above has been integrated into
the Xlib function library of the X client,
so that a programmer can now invoke the
new functions just like other Xlib
functions.
Current status is that the extensions to X
server and X client are completed and
running. Current work is concentrating on
new movie protocols for upper layers.
Standards used: JPEG, MPEG, H.261
Papers/reports: "X-MOVIE: Transmission and
Presentation of Digital Movies under X",
B. Lamparter and W. Effelsberg, Network
and Operating System Support for Digital
Audio and Video, 2nd International
Workshop, Heidelberg, p328, November 1991.
"MTP: A Movie Transmission Protocol for
Multimedia Applications", B. Lamparter, W.
Effelsberg and N. Michl, Computer
Communication Review, p71, July 1992.
"MCAM: An Application Layer Protocol for
Movie Control, Access, and Management", R.
Keller and W. Effelsberg, Technical Report
TR-1/93, Fakultat fur Mathematik und
Informatik, Universitat Mannheim, Germany,
January 1993.
Contact point: W Effelsberg
(effelsberg@pi4.informatik.uni-
mannheim.de)
University of Mannheim
Praktische Informatik IV
W-6800 Mannheim 1
Germany
Phone: +49 621 292 3131
Fax: +49 621 292 5745
Date of entry: 18 January 1993
Project name: ZenithZenith
Funding Body: SERC (GB)
Participants: University of Lancaster(GB)
University of Kent (GB)
BT Research Laboratories (GB)
Timescale: October 1989 to September 1992
Project aims: To establish a set of principles which
will assist designers and developers of
object management systems intended for
distributed multimedia design
environments.
To implement a prototype generalised
object management system.
Description: Zenith is a research prototype of an
object management system which is intended
to meet the data management requirements
of the next generation of application
domains such as office information
systems, integrated project support
environments and geographical information
systems. Zenith is designed to provide a
flexible, adaptable platform for managing
distributed multimedia objects, on top of
which specialised applications may easily
be built. The Zenith system has formed
the basis of a "conferencing" application
within ICI plc, involving microscope image
analysis by groups of scientists.
Standards used:
Papers/reports: "The Zenith Project: A Generalised
Object Management System for a locally
Distributed Multimedia Design
Environment", editor J. Mariani, February
1992. (This booklet contains three papers
produced as part of the Zenith project).
Contact point: John A. Mariani (jam@comp.lancs.ac.uk)
Department of Computing
Lancaster University
Bailrigg
Lancaster
LA1 4YR
Great Britain
Phone: +44 524 65201
Date of Entry: 1 December 1992
Project name: (none)[BBN]
Institution: BBN (US)
Description: BBN is doing a new video-conferencing
system which will carry PictureTel codec
data over ST-2, and perhaps audio over a
different ST-2 stream. The transport layer
is not very important; IP multicast would
work equally well. Significant effort is
devoted to conference-control issues, with
fully distributed control of multipoint
conferences exchanging all sorts of data.
Right now it happens to be video and
sound, but it could equally well be
simulation data, shared images, or
whatever. Contact Chip Elliott
(celliott@com.bbn) for further
information.
Project name:
Institution: CWI, Amsterdam (NL)
Description: Contact Dick Bulterman.
Project name: ACME[ACME]
Institution: UC Berkeley (US)
Description: Contact anderson@snow.berkeley.edu
Project name: ACT[ACT]
Institution: University College London (GB)
Description: Work has just started on the ACT project
(Advanced Communication in Teaching).
Initially, this centres on the design of a
multimedia database to be used for the
storage and distribution of multimedia
learning materials, both for consumption
by students and for the presentation of
coursework.
Project name: CAVECAT[CAVECAT]
Institution: University of Toronto (CA)
Description:
Project name: DSI[DSI]114
Institution: ISI (US)
Description: Contact schooler@venera.isi.edu
Project name: ELISE[ELISE]
Institution: De Montford University, Leicester (GB)
Description: Electronic Library Image Services for
Europe. Contact Mel Collier (Phone: +44
533 577039).
Project name: Etherphone[Etherphone]
Institution: UCSD (US)
Xerox PARC (US)
Description: Deals mainly with audio, but which has
been extended of late to manage video as
well.
Project name: GUIDANCE[GUIDANCE]
Institution: RACE programme (Commission of the European
Community)
Description:
Project name: Hydra[Hydra]
Institution: University of Toronto (CA)
Description:
Project name: IMEX[IMEX]
Institution: RACE II programme (Commission of the
European Community)
Description: Contact jpl@gti.upm.es.
Project name: ISA[ISA]
Institution: ANSA (GB)
Description: Contact adc@ansa.co.uk, or Chris Jones
at Architecture Project Management
(cwj@apm.co.uk).
Project name: Liveboard[Liveboard]
Institution: Xerox PARC (US)
Description:
Project name: Media Space[MediaSpace]
Institution: Xerox PARC (US)
Description:
Project name: MERMAID[MERMAID]
Institution: NEC (JP)
Description:
Project name: MMT[MMT]
Institution: IBM Thomas J Watson Research Centre
(US)
Description:
Project name: Pandora[Pandora]
Institution: Olivetti, Cambridge (GB)
Description:
Project name: PREPARE[PREPARE]
Institution: University College London (GB)
Description: The PREPARE project is aimed at
investigating multimedia applications over
interconnected LAN, Wide Area ATM, MAN and
B-ISPBX. The project is building the
network this autumn (1992).
Project name: TeamWorkStation[TeamWorkStation]
Institution: NTT Labs (US)
Description:
Project name: TINA[TINA]
Institution: TINA
Description: Telecommunications Information
Networking Architecture is a collaborative
effort to define a standard framework for
telecommunications networking in the
context of new multi-service networks,
telecommunications services and ISO
standardisation. Telecommunications
companies throughout Europe and the USA
are represented.
3. Standards
CCITT/ISO standards
F.700 70
G.711 71
G.721 72
G.722 73
G.725 74
H.221 75
H.242 76
H.261 77
H.230 78
HyTime 79
IIF 81
JBIG 83
JPEG 84
MHEG 85
MPEG 87
ODA 89
T.80 91
X.400 92
[G.723] 95
[G.726] 95
[G.727] 95
[G.728] 95
[G.764] 95
[G.765] 95
[H.200] 95
[H.241] 95
H.243 95
[T.120] 95
Internet standards
IP Multicast 96
MIME 97
RTP 99
ST-2 101
[RFC741] 102
[Xv and mvex] 102
Proprietary standards
Bento 103
GIF 105
QuickTime 106
RIFF 108
[DVI] 110
[MIDI] 110
Name: F.700F.700
Reference: F.711 - F740
Version: 1992
Sponsoring body: CCITT
Status: To be ratified at March 1993 CCITT
Plenary.
Brief description: Audiographic, Videotelephony and
Videoconference service standards.
Detailed description: The individual recommendations
are as follows:
F.711 Audiographic Conference
Teleservice for ISDN
F.720 Videotelephony Services General
F.721 Videotelephony Teleservices for
ISDN
F.722 Videotelephony Services General
F.730 Videoconference Service General
F.732 Broadband Videoconference Services
F.740 Audiovisual Interactive Services
(AVIS)
Products:
Further information:
Date of entry: 19 January 1993
Name: G.711G.711
Reference: G.711
Version: B (1988)
Sponsoring body: CCITT
Status: Recommendation currently in force
Brief description: Pulse Code Modulation (PCM) of voice
frequencies
Detailed description: 64 kbit/s 8kHz 8-bit PCM audio
encoding.
Products:
Further information:
Date of entry: 15 December 1992
Name: G.721G.721
Reference: G.721
Version: B (1988)
Sponsoring body: CCITT
Status: Recommendation currently in force
Brief description: 32 kbit/s adaptive differential pulse
code modulation (ADPCM) for audio
encoding.
Detailed description:
Products:
Further information:
Date of entry: 15 December 1992
Name: G.722G.722
Reference: G.722
Version: B (1988)
Sponsoring body: CCITT
Status: Recommendation currently in force
Brief description: 7 KHz audio encoding within 64 kbit/s
Detailed description:
Products:
Further information:
Date of entry: 15 December 1992
Name: G.725G.725
Reference: G.725
Version: B (1988)
Sponsoring body: CCITT
Status: Recommendation currently in force
Brief description: System Aspects of the use of 7 kHz
audio codec within 64 kbit/s
Detailed description:
Products:
Further information:
Date of entry: 15 December 1992
Name: H.221H.221
Reference: H.221
Version: R1 (12/90)
Sponsoring body: CCITT
Status: Recommendation currently in force
Brief description: Frame structure for a 64 to 1920
kbit/s channel in audiovisual
teleservices.
Detailed description: Defines a frame structure for
audiovisual teleservices in single or
multiple B or H0 channels or a single H11
or H12 channel which makes the best use of
the characteristics and properties of the
audio and video encoding algorithms, of
the transmission frame structure and of
the existing recommendations. It offers
several advantages:
It takes into account Recommendations
G.704, X.301/I.461, etc. It may allow
the use of existing hardware and
software.
It is simple, economic and flexible. It
may be implemented on a single
microprocessor using well known hardware
principles.
It is a synchronous procedure. The exact
time of a configuration change is the
same in the transmitter and the
receiver.
It needs no return link for audiovisual
signal transmission, since a
configuration is signalled by repeatedly
transmitted codewords.
Very secure in case of transmission
errors, since the code controlling the
multiplex is protected by double-error
correcting code.
Allows synchronisation of multiple 64
kbit/s or 384 kbit/s connections and the
control of the multiplexing of audio,
video, data and other signals within the
synchronised multiconnection structure
in the case of multimedia services such
as videoconferencing.
It can be used in multipoint
configurations, where no dialogue is
needed to negotiate the use of a data
channel.
It provides a variety of data bit-rates
(from 300 b/s up to almost 2 Mb/s) to
the user.
Closely related to H.261 & H.242.
Supersedes H.220
Products: Codecs from BT, GPT, Picturetel, Videotel
& others
Further information:
Date of entry: 10 December 1992
Name: H.242H.242
Reference: H.242
Version: N (12/90)
Sponsoring body: CCITT
Status: Recommendation currently in force
Brief description: Audiovisual communication using
digital channels up to 2 Mbit/s
Detailed description: Recommendation H.242 should be
associated with Recommendations G.725,
H.221 and H.230.
A number of applications utilising narrow
(3 kHz) and wideband (7 kHz) speech
together with video and/or data have been
identified, including high quality
telephony, audio and videoconferencing
(with or without various kinds of
telematic aids), audiographic conferencing
and so on. More applications will
undoubtedly emerge in the future.
To provide these services, a scheme is
recommended in which a channel
accommodates speech, and optionally video
and/or data at several rates, in a number
of different modes. Signalling procedures
are required to establish a compatible
mode upon call set-up, to switch between
modes during a call and to allow for call
transfer.
Some services will require only a single
channel, which could according to the
procedures in Recommendation H.242 be B
(64 kbit/s), H0 (384 kbit/s), H11 (1536
kbit/s) or H12 (1920 kbit/s). Other
services will require the establishment of
two or more connections providing B or H0
channels: in such cases the first
established is called hereafter the
initial channel while the others are
called additional channels.
All audio and audiovisual terminals using
G.722 audio coding and/or G.711 speech
coding or other standardised audio codings
at lower bit rates should be compatible to
permit connection between any two
terminals. This implied that a common mode
of operation has to be established for the
call. The initial mode might be the only
one used during a call or, alternatively,
switching to another mode can occur as
needed depending on the capabilities of
the terminals. Thus, for these terminals
an in-channel procedure for dynamic mode
switching is required.
Recommendation H.242 develops these
considerations and describes recommended
in-channel procedures.
Products: Codecs from BT, GPT, Picturetel, Videotel
& others.
Further information: Closely related to H.261 &
H.221. Supersedes H.220
Date of entry: 25 November 1992
Name: H.261H.261
Reference: H.261
Version: R1 (12/90)
Sponsoring body: CCITT
Status: Recommendation currently in force
Brief description: Video Codec for Audiovisual Services
at p x 64 kbit/s
Detailed description: Recommendation H.261 describes
the video coding and decoding methods for
the moving picture component of
audiovisual services at the rate of p x 64
kbit/s, where p is in the range 1 to 30.
It describes the video source coder, the
video multiplex coder and the transmission
coder.
This standard is intended for carrying
video over ISDN - in particular for face-
to-face videophone applications and for
videoconferencing. Videophone is less
demanding of image quality, and can be
achieved for p=1 or 2. For
videoconferencing applications (where
there are more than one person in the
field of view) higher picture quality is
required and p must be at least 6.
H.261 defines two picture formats: CIF
(Common Intermediate Format) has 288 lines
by 360 pixels/line of luminance
information and 144 x 180 of chrominance
information; and QCIF (Quarter Common
Intermediate Format) which is 144 lines by
180 pixels/line of luminance and 72 x 90
of chrominance. The choice of CIF or QCIF
depends on available channel capacity - eg
QCIF is normally used if p<3.
The actual encoding algorithm is similar
to (but incompatible with) that of MPEG.
Another difference is that H.261 needs
substantially less CPU power for real-time
encoding than MPEG. The algorithm
includes a mechanism which optimises
bandwidth usage by trading picture quality
against motion, so that a quickly-changing
picture will have a lower quality than a
relatively static picture. H.261 used in
this way is thus a constant-bit-rate
encoding rather than a constant-quality,
variable-bit-rate encoding.
Products: H.261 codecs have been implemented in VLSI
and are now built in to commercially
available codec equipment.
Further information: Document available on line on:
src.doc.ic.ac.uk:/doc/ccitt-
standards/ccitt/1992/h
See also "Overview of the p*64 kbit/s
Video Coding Standard", M. Liou,
Communications of the ACM, April 1991.
Date of entry: 15 December 1992
Name: H.320H.230
Reference: H.320
Version: N (12/90)
Sponsoring body: CCITT
Status: Recommendation currently in force
Brief description: Narrow Band Visual Telephone systems
and terminal equipment
Detailed description: Recommendation H.320 covers the
technical requirements for narrow-band
visual telephone services defined in
H.200/AV.120-Series Recommendations, where
channel rates do not exceed 1920 kbit/s.
Note - It is anticipated that
Recommendation H.320 will be extended to a
number of Recommendations each of which
would cover a single videoconferencing or
videophone service (narrow-band,
broadband, etc.). However, large parts of
these Recommendations would have identical
wording, while in the points of divergence
the actual choices between alternatives
have not yet been made; for the time
being, therefore, it is convenient to
treat all the text in a single
Recommendation.
The service requirements for visual
telephone services are presented in
Recommendation H.200/AV.120-Series; video
and audio coding systems and other
technical set aspects common to
audiovisual services are covered in other
Recommendations in the H.200/AV.200-
Series.
Products:
Further information:
Date of entry: 15 December 1992
Name: HyTimeHyTime
Reference: ISO 10744
Version: 1992
Sponsoring body: ISO (JTC1/SC18/WG8)
Status: International Standard
Brief description: SGML-based standard for hypermedia
documents.
Detailed description: HyTime (Hypermedia/Time-Based
Structuring Language) is a standardised
infrastructure for the representation of
integrated, open hypermedia documents. It
was developed principally by ANSI
committee X3V1.8M, and was subsequently
adopted by ISO.
The HyTime standard specifies how certain
concepts common to all hypermedia
documents can be represented using SGML.
These concepts include:
association of objects within documents
with hyperlinks
Placement and interrelation of objects
in space and time
logical structure of the document
inclusion of non-textual data in the
document
An "object" in HyTime is part of a
document, and is unrestricted in form - it
may be video, audio, text, a program,
graphics, etc.
SGML (Standard Generalized Markup
Language: ISO 8879) is a metalanguage
which is used to specify document markup
schemes called Document Type Definitions
(DTDs). HyTime is not itself a DTD, but
provides constructs and guidelines for
making DTDs for describing Hypermedia
documents. For instance, the Standard
Music Description Language (SMDL: ISO/IEC
Committee Draft 10743) defines a DTD which
is an application of HyTime.
HyTime consists of six modules:
Base module. This provides facilities
required by other modules, including
"xenoforms" for specifying application-
defined expressions, and identification
of policies for coping with changes to a
document - "activity tracking".
Finite Coordinate Space module. This
allows for an object to be scheduled in
time and/or space (which HyTime treats
equivalently) within a bounding box
called an "event".
Location Address module. This specifies
how to identify locations of document
objects by name, by coordinate location,
or by semantic construct.
Hyperlinks module. Five different types
of hyperlink are provided for.
Event Projection module. This specifies
how events in a source Finite Coordinate
Space (FCS) are to be mapped onto a
target FCS.
Object Modification module. This allows
for individual objects to be modified
before rendition, in an object-specific
way.
Products: A public-domain SGML parser (ARC SGML) is
available. TechnoTeacher (address below)
are producing a HyTime engine. Sema Group
are also understood to be developing a
HyTime product.
Further information: HyTime Special Interest Group
(SIGHyper)
Steven R. Newcomb, Chairman
(srn@cmr.fsu.edu)
TechnoTeacher Inc
1810 High Road
Tallahassee
Florida 32303-4408
USA
Phone: +1 904 422 3574
Fax: +1 904 386 2562
There are FTP sites at:
ftp.ifi.uio.no:SIGhyper
mailer.cc.fsu.edu:pub/sgml
The following articles are useful:
"The HyTime Hypermedia/Time-based
Document Structuring Language", S.
Newcomb, N. Kipp and V. Newton,
Communications of the ACM, p67, November
1991.
"Emerging Hypermedia Standards" B.
Markey, Multimedia for Now and the
Future (Usenix Conference Proceedings),
p59, June 1991.
See also newsgroup comp.text.sgml
Date of entry: 20 January 1993
Name: IIFIIF
Reference: ISO 12087-3
Version:
Sponsoring body: ISO (JTC1/SC24/WG7)
Status: Draft International Standard
Brief description: Image Interchange Facility
Detailed description: The Image Interchnage Facility
(IIF) is part of the first International
Image Processing and Interchange Standard
(IPI), which is under elaboration by
ISO/IEC JTC1/SC24. It comprises both a
data format definition and a gateway
functional specification.
The main component of the IIF is the
definition of a data format for exchanging
arbitrarily structured image data. The
IIF defines a format that can be used
across application boundaries and that can
easily be integrated into international
communication services. Besides the
definition of a file format, there are
definitions of parsers, generators, and
format converters to enhance open image
communication.
The IIF approach clearly distinguishes
between the image structure (a data type-
oriented description of the image), image
attributes (expressing colourimetric and
geometric semantics), the sequential data
organisation (managing data partitioning
and periodicity organisation), and the
data encoding/compression. The syntax
specification and the data encoding of
syntax entities use ASN.1 and the Basic
Encoding Rules respectively. For the
compressed representation, the following
standards are referenced: JBIG, facsimile
Group 3 and 4, JPEG, and MPEG.
Besides the data format specification, the
IIF also encompasses functionality for
generating and parsing image data, for
compressing and decompressing, and for the
exchange of image data between the
application program, the Programmer's
Imaging Kernel System (PIKS), which is
Part 2 of the IPI standard, and
storage/communication devices. This
functionality is located in the so-called
IIF Gateway. The IIF gateway controls the
import and export of image data to and
from applications, as well as to and from
the PIKS.
The IIF may serve as a future image
content architecture of the Open Document
Architecture (ODA).
Work is going on to develop a (multimedia)
electronic mail application on top of
X.400, using IIF.
Products:
Further information: "ISO/IEC's image interchange
format", C. Blum and G. R. Hofmann, SPIE
Proceedings Vol. 1659, San Jose, p130
February 1992.
IIF editor:
Christof Blum (blum@igd.fhg.de)
Fraunhofer Institute for Computer Graphics
(IGD)
Wilhelminenstr. 7
W-6100 Darmstadt
Germany
Phone: +49 6151 155 145 or 140
Fax: +49 6151 155 199
Date of entry: 15 December 1992
Name: JBIGJBIG
Reference:
Version:
Sponsoring body: ISO
Status:
Brief description: Binary image encoding standard
Detailed description: JBIG is a lossless compression
algorithm for binary (one bit/pixel)
images. The intent of JBIG is to replace
the current, less effective group 3 and 4
fax algorithms.
JBIG models the redundancy in the image as
the correlations of the pixel currently
being coded with a set of nearby pixels
called the template. An example template
might be the two pixels preceding this one
on the same line, and the five pixels
centred above this pixel on the previous
line. Note that this choice only involves
pixels that have already been seen from a
scanner.
The current pixel is then arithmetically
coded based on the eight-bit (including
the pixel being coded) state so formed.
So there are (in this case) 256 contexts
to be coded. The arithmetic coder and
probability estimator for the contexts are
actually IBM's (patented) Q-coder. The Q-
coder uses low precision, rapidly
adaptable (those two are related)
probability estimation combined with a
multiply-less arithmetic coder. The
probability estimation is intimately tied
to the interval calculations necessary for
the arithmetic coding. JBIG actually goes
beyond this and has adaptive templates.
You can use JBIG on grey-scale or even
colour images by simply applying the
algorithm one bit-plane at a time. You
would want to recode the grey or colour
levels first though, so that adjacent
levels differ in only one bit (called Gray-
coding). This works well up to about six
bits per pixel, beyond which JPEG's
lossless mode works better. You need to
use the Q-coder with JPEG also to get this
performance.
Products:
Further information: There is a description of the Q-
coder as well as the ancestor of JBIG in
the November 1988 issue of the IBM Journal
of Research and Development. This is a
comprehensive set of five articles that
describe the Q-coder and a bi-level image
coder that uses the Q-coder.
Date of entry: 3 December 1992
Name: JPEGJPEG
Reference:
Version:
Sponsoring body: CCITT | ISO (JTC1/SC2/WG10)
Status: Committee Draft
Brief description: Compression Standard for continuous-
tone still images
Detailed description: JPEG is a standardised image
compression mechanism. JPEG stands for
Joint Photographic Experts Group, the
original name of the committee that wrote
the standard. JPEG is designed for
compressing either full-colour (24 bit) or
gray-scale digital images of "natural"
(real-world) scenes. JPEG does not handle
black-and-white (one bit/pixel) images,
nor does it handle motion picture
compression.
JPEG is "lossy", meaning that the image
you get out of decompression isn't quite
identical to what you originally put in.
The algorithm achieves much of its
compression by exploiting known limitation
of the human eye, notably the fact that
small colour details aren't perceived as
well as small details of light-and-dark.
Thus, JPEG is intended for compressing
images that will be looked at by humans.
If you plan to machine-analyse your
images, the small errors introduced by
JPEG may well be a problem for you, even
if they are invisible to the eye.
A useful property of JPEG is that the
degree of lossiness can be varied by
adjusting compression parameters. This
means that the image maker can trade off
file size against output image quality.
You can make extremely small files if you
don't mind poor quality; this is useful
for indexing image archives, making
thumbnail views or icons, etc etc.
Conversely, if you aren't happy with the
output quality at the default compression
setting, you can jack up the quality until
you are satisfied, and accept lesser
compression.
Although it handles colour files well, it
is limited in handling black-and-white and
files with sharp edges (files come out
very large). The processing costs, even
on up-to-date computers, is also high.
Products: Many products now use this algorithm.
There is free JPEG source code available
from the Independent JPEG group, at many
FTP sites.
Further information: Independent JPEG group at jpeg-
info@uunet.uu.net. JPEG software and file
specifications are available from several
FTP sites, including
ftp.uu.net:/graphics/jpeg.
See the article on JPEG in Communications
of the ACM, April 1991. The article is
also available at the above FTP site.
Date of entry: 21 December 1992
Name: MHEGMHEG
Reference: T.170 | ISO
Version:
Sponsoring body: CCITT | ISO (JTC1/SC2/WG12)
Status: Committee Draft
Brief description: Standard for hypermedia document
representation.
Detailed description: MHEG stands for the Multimedia
and Hypermedia Information Coding Experts
Group. This group is developing a
standard "Coded Representation of
Multimedia and Hypermedia Information",
commonly called MHEG. The standard is
likely to be published in two parts - part
one being object representations and part
two being hyperlinking.
MHEG is suited to interactive hypermedia
applications such as on-line textbooks and
encyclopaedia. It is also suited for many
of the interactive multimedia applications
currently available (in platform-specific
form) on CD-ROM. MHEG could for instance
be used as the data structuring standard
for a future home entertainment
interactive multimedia appliance.
To address such markets, MHEG represents
objects in a non-revisable form, and is
therefore unsuitable as an input format
for hypermedia authoring applications: its
place is perhaps more as an output format
for such tools. MHEG is thus not a
multimedia document processing format -
instead it provides rules for the
structure of multimedia objects which
permits the objects to be represented in a
convenient form (eg video objects could be
MPEG-encoded). It uses ASN.1 as a base
syntax to represent object structure, but
allows for the use of other syntax
notations - an SGML syntax is also
specified.
MHEG objects (which may be textual
information, graphics, video, audio, etc)
may be of four types:
Input object (ie a user control such as
a button or menu)
Output object (eg graphics, audio visual
display, text)
Interactive object (a "composite" object
containing both input and output
objects)
Hyperobject ( a "composite" object
containing both input and output
objects, with links between them).
MHEG supports various synchronisation
modes, for presenting output objects in
these relationships.
It will be some time before MHEG reaches
IS status. Its future will then depend on
market requirements and trends.
Products: None as yet, but British Telecom have
developed a demonstration application
called MADE - see the Research section of
the survey.
Further information: See "Emerging Hypermedia
Standards" B. Markey, Multimedia for Now
and the Future (Usenix Conference
Proceedings) June 1991.
"Standardizing Hypermedia Information
Objects", F. Kretz and F. Cola tis, IEEE
Communications Magazine, p60, May 1992.
Date of entry: 30 November 1992
Name: MPEGMPEG
Reference: ISO 11172
Version: MPEG I
Sponsoring body: ISO (JTC1/SC2/WG11)
Status: Committee Draft
Brief description: Standard for compressed video and
audio
Detailed description: MPEG (Moving Pictures Expert
Group) is the name of the ISO committee
which is working on digital colour video
and audio compression, and by extension
the name of the standard they have
produced.
MPEG defines a bit-stream representation
for synchronised digital video and audio,
compressed to fit into a bandwidth of 1.5
Mbit/sec. This corresponds to the data
retrieval speed from CD ROM and DAT, and a
major application of MPEG is the storage
of audio visual information on this media.
MPEG is also gaining ground on the
Internet as an interchange standard for
video clips.
The MPEG standard is the three parts -
video encoding, audio encoding, and
"systems" which includes information about
the synchronisation of the audio and video
streams. The video stream takes about
1.15 Mbit/s, and the remaining bandwidth
is used by the audio and system data
streams.
MPEG video encoding starts with a fairly
low-resolution (352 x 240 pixels x 30
frames/s in the US; 352 x 288 x 25
frames/s in Europe) video picture. RGB
pixel information is converted to
chrominance/luminance and a complex, lossy
compression algorithm is applied. The
algorithm takes the time axis as well as
spatial axes into account, so a good
compression ration is achieved when the
picture is relatively unchanging (and vice
versa). The compressed data contains
three types of frames: I (intra) frames
are coded as still images; P (predicted)
frames are deltas from the most recent
past I or P frame; and B (bidirectional)
frames are interpolations between I and P
frames. I frames are sent once every 10
or 12 frames. Reconstructing a B frame
for display requires the preceding and
following I and/or P frames, so these are
sent out of time-order.
Substantial computing power is required to
encode MPEG data in real time - perhaps
several hundred MIPS to encode 25
frames/second. Decoding is not quite so
demanding.
The quality of MPEG-encoded video has been
compared to that of a VHS video recording.
MPEG II is under development. MPEG II is
designed to offer higher quality at a
bandwidth of between 4 and 10 Mbit/s.
This is too fast for playback from CD
using today's technology.
Products: Phillips have developed an MPEG decoder
chip, which will go into their CD-I
product range.
Xing Technology Corp (California, USA)
offer video capture and encode/decode
hardware and software for PCs which uses
MPEG and JPEG.
Ingenieurbuero Gatz und Hartmann (Berlin,
Germany) offer a PC video input board and
an off-line MPEG encoding program.
Maximum video clip length is 20s (limited
by 32Mb of expanded memory in the PC).
Optibase Inc (California, USA) have board-
level products for PCs, called MPG-1000
(codec), MPG-2000 and MPG-2100 (playback
only)
There are freeware MPEG software
decoder/players for DOS, MS Windows and X
windows - see FTP sites below for details.
Further information: A FAQ for MPEG is available from
Frank Gadegast (phade@cs.tu-berlin.de).
Anonymous FTP sites are:
phoenix.oulu.fi:pub/mpeg
toe.cs.berkley.edu:pub/multimedia/mpeg
A useful description of MPEG is "MPEG: A
Video Compression Standard for Multimedia
Applications", D. Le Gall, Communications
of the ACM, April 1991.
Date of entry: 30 November 1992
Name: ODA (Office [Open] Document Architecture
and Interchange Format)ODA
Reference: T.410 | ISO 8613 (Parts 1 to 8)
Version: 1989
Sponsoring body: CCITT | ISO (JTC1/SC18/WG3)
Status: Recommendation currently in force |
International Standard
Brief description: ODA standard is concerned with the
open interchange of documents
Detailed description: Note: the current version of
ISO 8613 names the standard as Office
Document Architecture and Interchange
Format, while CCITT recommendations refer
to "Open" rather than "Office".
The ODA standards are part of a group of
related standards concerned with
documents, their content and how they may
be conveyed between systems. SGML
(Standard Generalized Markup Language) and
various related standards are other
members of this group.
Through the standards, a wide range of
documents, from simple text-only documents
such as office memoranda and letters, to
complex documents such as technical
reports may be encoded. These complex
documents may contain text, raster
graphics, computer graphics and may well
require complex layout specifications.
The ODA standards support a very wide
range of features and tend to be abstract
in nature, hence industry experts have
clarified the concept by defining Document
Application Profiles (DAPs). These
subsets provide support for document
interchange between similar systems, which
have a more restricted range of features.
These DAPs will be published as ISO
standards known as International
Standardised Profiles (ISPs).
The current target for ODA implementors is
seen as the open interchange of mixed-
content 'word processor' documents. The
future for ODA is not as limited as this
might suggest, as a number of major
suppliers are known to have products under
development. However, strong support for
SGML and SDIF (SGML Data Interchange
Format) is lacking, reflecting the fact
that few SGML suppliers are associated
with OSI.
Some history:
Jun 1989 ODA standards published.
Mar 1991 Formation of ODA Consortium
to sponsor an ODA toolkit.
Members are Bull, DEC, IBM, ICL,
Siemens and Unisys.
Jun 1991 Several addenda and more than
20 technical corrigenda now
approved. Will be published in
1992 as revised version of
standards.
Jun 1991 Drafts for "HyperODA"
(extensions to ODA to support
hypermedia applications) and API
to support document manipulation
functions for use in interactive
applications.
Oct 1991 New draft for "HyperODA" was
produced. New part of standard
was discussed for audio content.
Group dealing with conformance
testing considered ballot comments
on TR 10183-Technical Report on
ISO 8613 Implementation Testing.
Jan 1992 EWOS ODA expert group meet to
discuss ISPs and ODAs relationship
with other standards (CGM, raster
graphics standards and EDI)
May 1992 SC18 Plenary deals with:-
CCITT collaborative work, SGML/ODA
interworking and imaging.
July 1992 EWOS SGML/ODA convergence
team reports.
A development programme is underway which
will result in major enhancements to ODA
being agreed in 1992/3. These being
progressed by full collaboration between
ISO/IEC and CCITT and will extend both the
content (audio, spreadsheets, colour,
business graphics, specialist notations)
and structural features (annotations,
hypermedia support, complex tabular
layout, document access and manipulation
support, revision accountancy) of ODA.
Products: ODA Consortium has announced a set of APIs
that will form the foundation of the ODA
toolkit. Products at varying levels of
implementation are available (or planned)
from: British Telecom, Bull HN, DEC, IBM,
Olivetti, Rank Xerox, Sema Group, Sequent,
Siemens and Unisys.
Further information: Contact ODA Consortium on +32 2
774 9623
Date of entry: 18 December 1992
Name: T.80T.80
Reference: T.80 to T.83
Version: N (09/92)
Sponsoring body: CCITT
Status: Recommendations currently in force
Brief description:
Detailed description: The following standards are all
related. The titles suggest that they may
be the CCITT versions to the ISO JBIG/JPEG
documents.
T.80 Common components for image
compression and communication -
basic principles.
T.81 Digital compression and encoding
of continuous tone still images.
T.82 Progressive compression techniques
for bi-level images.
T.83 Compliance testing.
Products:
Further information:
Date of entry: 15 December 1992
Name: X.400X.400
Reference: X.400 | ISO 10021 (Parts 1-7)
Version: CCITT-1984,1988,1992 | ISO/IEC-1990
Sponsoring body: CCITT | ISO
Status: Recommendation currently in force |
International Standard
Brief description: Standard for the exchange of
multimedia messages by store-and-forward
transfer.
Description: The aim of the X.400 standards is to
provide an international service for the
exchange of electronic messages without
restriction on the types of encoded
information conveyed.
Work on X.400 began in 1980 within CCITT
and resulted in the publication of the
1984 Recommendations, which still forms
the basis of many of the products
available today. Since then CCITT formed
a collaborative partnership with ISO for
the further development of the technology
and published technically aligned text in
1988 (1990 in ISO) for the first major
revision of X.400.
The 1988 version of the standards
rectified many of the serious deficiencies
of the 1984 version and introduced a
variety of significant new services
(including security, distribution list
management, and the Message Store).
Versions published since 1988 contain
minor enhancements and bug fixes, but are
firmly based on the 1988 version.
Message handling technology is complex; as
well as the sheer technical difficulties
involved, as a global service it has had
to take account of political, commercial,
legal, and historical realities. Some
issues which are dependent on national
telecommunications regulation are not
covered by the International Standards and
are addressed by national standards.
The relatively poor penetration of X.400
messaging has been caused by a variety of
factors. The heavy investment in
developing 1984 products has lead to
considerable resistance to change,
regardless that global interconnectivity
is severely constrained in 1984 products,
and that 1984-1988 interworking degrades
the quality of service offered.
Paradoxically it is the attempt to recoup
the investment in 1984 products which is
impeding the introduction of 1988 products
that are essential for a highly functional
global messaging service.
X.400 makes a clear distinction between
message envelope, which controls the
message transfer process, and message
content, which is passed transparently
from originator to recipient. Hence any
type of encoded information may be
exchanged without loss or corruption. The
most common content-type in use is the
Interpersonal-messaging content-type; this
format divides content into two parts:
heading and body. Heading fields (with
labels such as 'from', 'to', and
'subject') convey standard items of
information. The message body consists of
one or more body parts, each of which may
contain a different type of encoded
information.
A number of body part types are defined as
'basic' in X.400: IA5Text, Teletex, Voice,
G3Facsimile, G4Class1, Videotex, Message,
FileTransfer. In addition to these, the
ExternallyDefined body part type allows
any identified data format to be conveyed,
such as word processing and spreadsheet
formats. A format is identified by the
assignment of a globally unique Object
Identifier. Commercial organisations can
acquire Object Identifiers at nominal cost
from their national standards
organisations. Alternatively, the
FileTransfer body part type may be used
for the transfer of structured and
unstructured data.
X.400 has two further features which make
it especially suitable for the conveyance
of multimedia information. Firstly, the
use of ASN.1, which guarantees data
transparency and offers a choice of
encodings, including a space-optimised
"packed encoding". Secondly, the use of
the Reliable Transfer Application Service
Element provides a very tolerant data
transfer mechanism with recovery from
connection failure. This is especially
important for multimedia messages which
are typically large.
There are several work items at various
stages of development.
Draft International Standardised
Profiles for X.400 have been published
and are under ballot. These are more
mature than the corresponding draft
European Prestandards.
Work on Message Store extensions is
currently on PDAM ballot and should be
issued for DAM ballot in March 1993.
Work on MHS Management covers a number
of topics; most are still at the stage
of working drafts.
MHS Routing is progressing slowly, and
will require a further round of
development before it is sufficiently
mature for balloting.
Group communication is currently
stalled, mainly due to lack of manpower.
However Japan is very interested in the
work so rapid progress is possible if
Japanese contributors appear.
Products: Many suppliers offer X.400 products, and
there have been a number of recent
announcements of 1988-based products. The
following list (which includes products
which don't carry multimedia data) is far
from complete:
BiMAIL, CDC MHS/4000, DC-Mail, DG AV/400,
EAN, HP X.400, ICL OfficePower, ISOCOR,
NAR400, NET400, OSITEL, OSIWare M400, PP,
QK-MHS, Retix X.400, Route400, SoftSwitch,
Sunlink MHS, UCLA/Mail400, UCOM.X,
WhiteMail, X/EM, XT-PP.
` The following X.400 gateway products are
known:
BanyanMail, DEC All-In-One, Lotus CC:Mail,
Microsoft Mail, TeamMail, WP Office,
WorldTalk.
Further information: A useful source of information
is available on the FTP server at Uni-
Erlangen, maintained by Markus Kuhn:
ftp.uni-erlangen.de:/pub/doc/ISO/english
Date of entry: 14 December 1992
Name: G.723[G.723]
Description: CCITT standard for conversion between
G.711 and lower-speed channels.
Name: G.726[G.726]
Description: Replaces G.721?
Name: G.727[G.727]
Description: Extension of G.726 for use over G.764
Name: G.728[G.728]
Description: Coding of Speech at 16 kbit/s using Low-
Delay Code Excited Linear Prediction (LD-
CELP). Audio encoding for
videoconferencing.
Name: G.764[G.764]
Description: Packetised Voice Protocol
Name: G.765[G.765]
Description: Associated with G.764
Name: H.200[H.200]
Description: Audio compression standard (forthcoming).
Name: H.241[H.241]
Description: Signalling for conferencing.
Name: H.243H.243
Description: Multipoint Video Codec Standard. Probably
a draft
Name: T.120[T.120]
Description: T.121-T.124: Network-independent audio
conferencing protocols.
Name: IP MulticastIP Multicast
Reference: RFC 1112
Version: August 1992
Sponsoring body: IETF Network Working Group
Status: Internet standard
Brief description: The extensions required to a host
implementation of the Internet Protocol
(IP) to support multicasting.
Detailed description: IP multicasting is the
transmission of an IP datagram to a host
group, which is a set of zero or more
hosts identified by a single IP
destination address. A multicast datagram
is delivered to all members of a
destination host group. The membership of
the host group is dynamic. A host group
may be transient or permanent.
Multicasting of this nature is essential
to optimise bandwidth usage for multiparty
conferencing applications.
Internetwork forwarding of IP multicast
datagrams is handled by multicast routers.
The special routing requirements of
multicast IP can be met in several
different ways. There are extensions to
the OSPF and BGP routing methods, and
there is a new routing method (CBT - Core
Based Trees). At the time of writing, it
seems that CBT is likely to be adopted as
the appropriate method of routing
multicast IP.
Products: vat, nv, ivs, NEVOT, sd and other remote
conferencing tools use IP multicast.
Multicast support is available as kernel
patches for SunOS 4.x.x, and is built in
to SunOS 5.
Further information: There are mailing lists
concerned with IP Multicast backbone
operations at the following addresses:
mbone-uk@nosc.ja.net (GB)
mbone-eu@sics.se (Europe)
mbone-oz@internode.com.au (Australia)
mbone@isi.edu (US and World)
Patches to various UNIX system kernels to
provide multicast support are available
from: gregorio.stanford.edu:/vmtp-ip.
Date of entry: 15 December 1992
Name: MIMEMIME
Reference: RFC 1341
Version:
Sponsoring body: Internet Architecture Board
Status: Proposed Internet Standard
Brief description: Multipurpose Internet Mail Extensions
Detailed description: MIME supports not only several
pre-defined types of non-textual message
contents, such as 8-bit 8000Hz-sampled ‘-
LAW audio, GIF image files, and PostScript
programs, but also permits you to define
your own types of message parts. A
typical MIME mail reader might:
Display GIF, JPEG and PBM encoded
images, using eg 'xv' in X windows.
Display PostScript parts (eg something
that prints to a PostScript printer, or
that invokes GhostScript on an X windows
display, or that uses Display
PostScript.)
Obtain external parts via Internet FTP
or via mail server.
Play audio parts on workstations that
support digital audio.
RFC 822 defines a message representation
protocol which specifies considerable
detail about message headers, but which
leaves the message content, or message
body, as flat ASCII text. RFC1341
redefines the format of message bodies to
allow multi-part textual and non-textual
message bodies to be represented and
exchanged without loss of information.
This is based on earlier work documented
in RFC 934 and RFC 1049, but extends and
revises that work. Because RFC 822 said
so little about message bodies, RFC 1341
is largely orthogonal to (rather than a
revision of) RFC 822.
MIME is designed to provide facilities to
include multiple objects in a single
message, to represent body text in
character sets other than US-ASCII, to
represent formatted multi-font text
messages, to represent non-textual
material such as images and audio
fragments, and generally to facilitate
later extensions defining new types of
Internet mail for use by co-operating mail
agents.
An associated document, RFC1342, extends
Internet mail header fields to permit
other than US-ASCII text data.
Products: Many mailers which support MIME are now
available.
Further information: The specification is available
as RFC 1341: "MIME (Multipurpose Internet
Mail Extensions): Mechanisms for
Specifying and Describing the Format of
Internet Message Bodies", N. Borenstein &
N. Freed.
Other associated RFCs are:
RFC 1342: "Representation of non-ASCII
text in Internet message headers", K.
Moore, June 1992
RFC 1343: "User agent configuration
mechanism for multimedia mail format
information", N. Borenstein, June 1992
Edward Vielmetti (emv@msen.com) is
preparing a FAQ on MIME. See also the
newsgroup comp.mail.mime.
Date of entry: 21 December 1992
Name: RTPRTP
Reference:
Version: October 27,1992
Sponsoring body: IETF Audio/Video Transport Working
Group
Status: Internet Draft (expires 1st April 1993)
Brief description: A Transport Protocol for Audio and
Video Conferences and other
Multiparticipant Real-Time Applications
Detailed description: Services typically required by
multimedia conferences are playout
synchronisation, demultiplexing, media
identification and active-party
identification. RTP is not restricted to
multimedia conferences, however, and other
real-time services such as data
acquisition and control may use its
services.
RTP uses the services of an end-to-end
transport protocol such as UDP, TCP, OSI
TPx, ST-2 or the like. The services used
are: end-to-end delivery, framing,
demutliplexing and multicast. The network
is not assumed to be reliable and is
expected to lose, corrupt, delay and
reorder packets.
RTP is supported by a real-time control
protocol (RTCP). Conferences encompassing
several media are managed by a reliable
conference protocol not discussed in the
RTP draft.
The draft summarises some discussions by
the AVT (audio/video transport) working
group. The draft builds on the operational
experience with Van Jacobson's and Steve
McCanne's vat audio conferencing tool as
well as implementation experience with
Henning Schulzrinne's NEVOT network voice
terminal.
Other protocols and standards referred to
are:
NVP - Network Voice Protocol RFC741
G.764 and G.765 - CCITT recommendations
for packet voice
The design goals of RTP are:
media flexibility
extensible
independent of lower-layer protocols
gateway compatible
bandwidth efficient
international
processing efficient
implementable
Services provided are:
framing
demultiplexing by conference/association
demultiplexing by media source
demultiplexing by media encoding
synchronisation between source(s) and
destination(s)
error detection
encryption
quality-of-service monitoring
RTP consists primarily of protocol header
for real-time data packets. In the
typical case, the RTP header is just 8
octets long and composed of the following
fields:
protocol version (2 bits, value 1)
flow identifier (6 bits)
option present bit
synchronisation bit (marks end of
synchronisation unit)
content type index (6 bits)
packet sequence number (16 bits)
timestamp, middle 32 bits of NTP-format
timestamp
Products: vat, NEVOT
Further information: This draft is available by
anonymous FTP from:
ftp.ripe.net:/pub/internet-drafts/ in the
files:
draft-ietf-avt-rtp-00.txt
draft-ietf-avt-encoding-00.txt
draft-ietf-avt-profile-00.txt
draft-ietf-avt-issues-00.ps, .txt
Date of entry: 15 December 1992
Name: ST-2ST-2
Reference: RFC 1190
Version: 2
Sponsoring body: Internet Network Working Group
Status: Internet Standard
Brief description: This memo defines the Internet Stream
Protocol, Version 2 (ST-2), an IP-layer
protocol that provides end-to-end
guaranteed service across an internet.
Detailed description: This specification obsoletes IEN-
119 "ST - A Proposed Internet Stream
Protocol". ST-2 is not compatible with
Version 1.
ST-2 is an internet protocol at the same
layer as IP. It differs from IP in that
it requires routers to maintain state
information describing the streams of
packets flowing through them.
ST incorporates the concept of streams
across an internet. Every intervening ST
entity maintains state information for
each stream that passes through it. The
stream state includes fowarding
information, including multicast support
for efficiency (required for
multiparticipant conferencing) and
resource information which allows network
or link bandwidth and queues to be
assigned to a specific stream. This pre-
allocation allows data packets to be
forwarded with low delay, low overhead and
low probability of loss due to congestion.
This allows ST-2 to give a real-time
application the guaranteed and predictable
communication characteristics it requires.
The data stream in an ST-2 connection is
essentially one-way, except that there is
a reverse-direction channel for control
messages.
Transport protocols above ST-2 of interest
to multimedia applications include Packet
Video Protocol (PVP) and the Network Voice
Protocol (NVP), which are end-to-end
protocols used directly by applications.
Products: Implementations by SICS (SE) and BBN (US)
exist.
Further information: "An Implementation of the
Revised Internet Stream Protocol (ST-2)",
C. Partridge and S. Pink, Journal of
Internetworking: Research and Experience,
March 1992.
Date of entry: 15 December 1992
Name: RFC 741[RFC741]
Description: Network Voice Protocol
Name: Xv and mvex[Xv and mvex]
Description: X extensions to incorporate video. Xv is
implemented in DEC's XMedia toolkit. See
the XMovie entry in the Research section
for another alternative.
Name: BentoBento
Reference:
Version: 1.0d4
Sponsoring body: Apple Computer
Status: Manufacturer-sponsored specification
created with the help of third parties and
offered to the industry in general in the
hope that it will become a de facto
standard.
Brief description: Platform-independent container
structure for networks of objects.
Detailed description: Bento is a specification for the
format of "object containers" and an
associated API. In this context, an
"object" such as a word-processor document
or a movie clip typically comprises some
metadata (data about the object's format)
and a value (the content of the object).
A "container" is some form of data storage
or transmission (eg a file or part of a
mail message). Bento containers are
defined by a set of rules for storing
multiple objects in such a container.
Bento does not require individual objects
to be "Bento-aware".
Bento can store deltas to an object, and
can store objects in compressed or
encrypted form, where
compression/encryption algorithms may be
specified externally. It can store
external references to data - for instance
to a large movie file (perhaps itself part
of a Bento container) stored on a
fileserver; and can also store a limited-
resolution version for use when the
fileserver version is unavailable.
Unlike other similar standards such as
ASN.1 and ODA, Bento allows for the
storage of multimedia objects in a medium-
specific interleaved layout (say, on a CD-
ROM) suitable for "just-in-time" real-time
display.
The Bento specification also contains an
API.
Bento:
is platform independent.
is suitable for random-access reading
(when a container is in RAM or on disk).
has an "update-in-place" mechanism
supported in the API, but not yet in
format specification or implementation.
has a globally unique naming system for
objects and their properties. Names can
be allocated locally for casual use or
registered for common use.
objects are extensible - new information
may be added to an object without
disrupting applications which don't
understand the new information.
supports links between objects.
provides recursive access to embedded
Bento containers.
can store a single object in several
different formats (eg with different
byte-ordering).
is not a general-purpose object database
mechanism.
Products: It is understood that portable C source
code should soon be available.
Further information: The Bento specification is
available from:
ftp.apple.com:apple/standards/Bento_1.0d4.
1
Date of entry: 19 January 1993
Name: GIF (Graphic Interchange Format)GIF
Reference:
Version: 87a and 89a
Sponsoring body: Compuserve Incorporated, Ohio, USA
Status: De facto industry standard
Brief description: Protocol for interchange of raster
graphic data
Detailed description: The Graphics Interchange Format
defines a protocol intended for the on-
line transmission and interchange of
raster graphic data in a way that is
independent of the hardware used in their
creation or display.
Compuserve Incorporated has granted a
limited, non-exclusive, royalty-free
license for the use of the Graphics
Interchange Format in computer software.
The Graphics Interchange Format is defined
in terms of blocks and sub-blocks which
contain relevant parameters and data used
in the reproduction of a graphic. A GIF
Data Stream is a sequence of protocol
blocks and sub-blocks representing a
collection of graphics. In general, the
graphics in a Data Stream are assumed to
be related to some degree, and to share
some control information.
A Data Stream may originate locally, as
when read from a file, or it may originate
remotely, as when transmitted over a data
communications line. The Format is defined
with the assumption that an error-free
Transport Level Protocol is used for
communications; the Format makes no
provisions for error-detection and error-
correction.
The GIF format utilises colour tables to
render raster-based graphics. The concept
of both global and local colour tables are
supported to enable the optimisation of
data streams. The decoder of an image may
use a colour table with as many colours as
its hardware is able to support, if an
image contains more colours than the
hardware can support algorithms not
defined in the 'standard' must be employed
to render the image. The maximum number
of colours supported by the 'standard' is
256.
Products: Many products now support GIF image format
files.
Further information: The document describing GIF, and
software implementing it, are widely
available on the Internet by anonymous
FTP.
Date of entry: 21 December 1992
Name: QuickTimeQuickTime
Reference:
Version: 1.5 Preliminary
Sponsoring body: Apple Computer, Inc
Status: Proprietary
Brief description: File format for the storage and
interchange of sequenced data, with cross-
platform support.
Detailed description: A QuickTime movie contains time
based data which may represent sound,
video or other time-sequenced information
such as financial data or lab results. A
movie is constructed of one or more
tracks, each track being a single data
stream.
A QuickTime movie file on an Apple
Macintosh consists of a "resource fork"
containing the movie resources and a "data
fork" containing the actual movie data or
references to external data sources such
as video tape. To facilitate the exchange
of data with systems which use single fork
files, it is possible to combine these
into a file which uses only the data fork
.
Movie resources are built up from basic
units called atoms, which describe the
format, size and content of the movie
storage element. It is possible to nest
atoms within "container" atoms, which may
themselves contain other container atoms.
One type of container atom is the "movie"
atom which defines the timescale, duration
and display characteristics for the entire
movie file. It also contains one or more
track atoms for the movie.
A track atom defines a single track of a
movie and is independent of any other
tracks in the movie, carrying its own
temporal and spatial information. Track
atoms contain status information relating
to the creation or editing of the track,
priority in relation to other tracks and
display and masking characteristics. They
also contain media atoms which define the
data for a track.
Media atoms contain information relating
to the type of data (sound, animation,
text etc) and information relating to the
QuickTime system component (ie driver)
that is to handle the data. Component-
specific information is contained in a
media information atom which is used to
map media time and media data.
The above is a very simplistic view of a
QuickTime movie resource. In fact there
are many more atom types which define a
wide variety of features and functions,
including a TEXT media atom which allows
displayed text to change with time, and
user-defined data atoms called "derived
media types". These allow for the custom
handling of data by overriding the media
handler with a user-supplied driver.
The actual movie data referred to by the
movie resources may reside in the same
file as the movie resource (a "self
contained" movie), or more commonly it may
reside in another file or on an external
device.
It is possible that QuickTime could become
a computer-industry standard for the
interchange of video/audio sequences.
Products: Support for this format is available for
Apple Macintosh System 7.1 free of charge.
"QuickTime for MS Windows" (version 1.1 is
scheduled for release early 1993) will
allow self-contained QuickTime movies to
play on Microsoft Windows without
conversion. Claims a common API for both
Windows and the Macintosh.
"QuickTime Movie Exchange Toolkit"
contains utilities for the conversion of
graphics from a range of platforms.
Apple have an agreement with Silicon
Graphics to provide limited QuickTime
support on SCI Iris workstations. This
will allow the creation and playing of
QuickTime movies on both platforms through
support for the QuickTime file format.
Further information: QuickTime Developers Guide,
Apple Computer Inc.
Date of entry: 15 December 1992
Name: RIFFRIFF
Reference:
Version:
Sponsoring body: Microsoft and IBM
Status: Proprietary
Brief description: File structure for multimedia
resources
Detailed description: RIFF (Resource Interchange File
Format) is a family of file structures
rather than a single format. RIFF file
architecture is suitable for the following
multimedia tasks:
Playing back multimedia data
Recording multimedia data
Exchanging multimedia data between
applications and across platforms
A RIFF file consists of a number of
"chunks" which identify, delimit and
contain each resource stored in the file.
Each chunk is defined as follows:
4 characters (the chunk type)
identifying how the data stored in the
chunk is represented.
A 32 bit unsigned number representing
the size of the data stored in the
chunk.
The binary data contained in the store.
There are two special chunks which allow
nesting of multiple chunks. These are the
"RIFF" chunk which combines multiple
chunks into a "form" and "LIST" which is a
list or sequence of chunks.
Certain chunk types (including all form
and list types) should be globally unique.
To guarantee this uniqueness there is a
registration scheme run by Microsoft ,
where new chunk types may be registered
and a list of current registrations may be
obtained.
The definition of a particular RIFF form
typically includes:
A unique 4 character code identifying
the form type.
A list of mandatory chunks.
A list of optional chunks.
A required order for the chunks.
Currently registered "forms" are
PAL Palette File Format (.PAL files)
RDIB RIFF Device Independent Bitmap
Format (.DIB files)
RMID RIFF MIDI Format (.MID files)
RMMP RIFF Multimedia Movie File Format
WAVE Waveform Audio Format (.WAV files)
The RIFF "LIST" chunk is identified by a 4
character "list type " code. If an
application recognises the list type it
should know how to interpret the sequence
of chunks, although any application may
read through the nested chunks and
identify them individually.
RIFX is a counterpart to RIFF, that uses
the Motorola integer byte ordering format
rather than the Intel format. There are no
currently defined RIFX forms or lists.
RIFF files are supported in Windows 3.1
under MS DOS, and by MMPM/2 under OS/2.
There is no sign yet of RIFF being adopted
on hardware platforms other than the PC.
Products: Windows 3.1 Filewalker is a RIFF file
viewing utility in the Microsoft Windows
multimedia development kit. Many products
support particular formats from the RIFF
family.
Further information: The specification is available
from:
uunet.uu.net:vendor/microsoft/multimedia.
Date of entry: 14 December 1992
Name: DVI[DVI]
Description: Intel's Digital Video Interactive video
compression technology. There is a
discussion list: dvi-
list@calvin.dgbt.doc.ca. An FTP archive
site for this list has been created on
debra.dgbt.doc.ca:/pub/dvi.
Name: MIDI[MIDI]
Description: Musical Instrument Digital Interface
4. Products
Conferencing products
BVCS 112
Cameo PVS 113
CU-SeeMe 114
DECspin 115
ES.F2F 116
IRIS 117
ivs 118
MacMICA 119
Nevot 120
nv 121
Person to Person/2 122
PICFON 123
sd 124
ShowMe 125
Slate 126
vat 127
VC7000 128
VCI/oem 129
VS1000 130
[Communique] 131
[Desktop Videoconferencing] 131
[mmcc] 131
[ShareVision] 131
[VISIT Video] 131
Other products
MAEstro 132
Metamail 133
MS Mail 135
Notecards 136
Notes 137
PACo 138
StarWorks 139
Xanadu 141
XMedia Tools 143
WhiteMail 145
[HyMinder] 146
Product name: BVCSBVCS
Version: 1
Manufacturer: Bitfield Oy
Tekniikantie 6
SF -02150
Espoo
Finland
Phone: +358 0 70018663
Fax: +358 0 4552240
Platform: PC (Windows and DOS)
Description: BVCS (Bitfield Video Communication System)
is a videoconferencing system over NetBIOS
LAN. It utilises an H.261 video/audio
codec board.
Bitfield provides a set of application
programming interfaces for Windows (as a
DLL) and DOS, allowing video applications
to be integrated into existing systems.
Future plans: ISDN will be supported soon.
Available from: Manufacturer
Price: $10,000 (US)
Standards: MPEG, JPEG
Further information: Simo Poikola
Bitfield Oy
Date of entry: 21 December 1992
Product name: Cameo PVS, Model 2001Cameo PVS
Version:
Manufacturer: Compression Labs Inc
2860, Junction Ave
San Jose
CA 95134
USA
Phone: +1 408 435 3000
Platform: Apple Macintosh
Description: Computer-based version of the AT&T
VideoPhone 2500. An external image
processor unit and attached video camera
encodes and passes data to an ISDN board
in the micro for onward transmission. The
performance is not said to be fast, but
the system is aimed at low-end
requirements rather than full-blown
videoconferencing.
Future plans: PC version expected 1993
Available from: Internet
4 Eagle's Wood
Woodlands Lane
Bradley Stoke
Bristol
BS12 4EU
Great Britain
Phone: +44 454 201000
Price: 2,000
Standards:
Further information:
Date of entry: 21 December 1992
Product name: CU-SeeMeCU-SeeMe
Version: 0.3
Manufacturer: Cornell University
Platform: Apple Macintosh
Description: Videoconferencing software for Apple Mac
over IP. Requires VideoSpigot board for
video transmission.
Future plans: Current version is "pre-alpha".
Available from: gated.cornell.edu:/pub/video
Price: Free
Standards:
Further information: Dick Cogger
(R.Cogger@cornell.edu)
Phone: +1 607 255 7566
Date of entry: 21 January 1993
Product name: DECspin (DEC Sound Picture Information
Network)DECspin
Version: 1.0
Manufacturer: DEC
Platform: DECstation 5000 (model 25 through 240),
Ultrix V4.3, DECmedia hardware
Description: DECspin uses packetized audio and video to
allow for desktop teleconferencing.
DECspin uses standard networking protocols
(TCP/IP and DECnet) along with either
hardware or software compression of
digitized audio and video.
Future plans:
Available from: Manufacturer.
Price:
Standards: JPEG, G.711
Further information: Diane Lapointe
Phone: +1 508 493 1327
Date of entry: 21 December 1992
Product name: ES.F2FES.F2F
Version: 1.0
Manufacturer: The Electronic Studio
7 Fitzroy Square
London
W1P 6HJ
Great Britain
Platform: Apple Macintosh
Description: A package which allows bilateral desktop
video conferencing and text and image
exchange. The people involved in the
conference can see and interact with the
same document, highlighting areas of a
diagram, for example, which are also
highlighted on the recipient's screen.
Speeds of 15 fps are achievable without
compression hardware. Appletalk and ISDN
networks are supported.
Future plans: H.261 compatibility and PC version
expected in 1993.
Available from: Manufacturer.
Price: from 1000
Standards:
Further information:
Date of entry: 21 December 1992
Product name: IRISIRIS
Version:
Manufacturer: SAT
Divion Communications d'Enterprise
Centre Tolbiac Massena
25 Quai Panhard et Levassor
75624 Paris CEDEX 13
France
Phone: +33 1 40 77 12 12
Platform: Apple Macintosh II or Quadra with 4Mb RAM
and Planet ISDN board.
Description: A hardware/software package which allows
bilateral desktop video conferencing.
Compressed colour video is carried over
ISDN, and audio over a normal voice
telephone channel. JPEG compression is
done in hardware.
Future plans:
Available from: David Catchpole
Satelcom
Satelcom House
Buckhurst Road
Ascot
Berkshire
Great Britain
Phone: +44 344 872677
Price: about 5,000 to 6,000
Standards: JPEG
Further information: Lionel Bonnot
Phone: +33 1 40 77 11 27
Fax: +33 1 40 77 11 50
Date of entry: 20 January 1993
Product name: ivsivs
Version: 2.0
Manufacturer: Thierry Turletti
(turletti@sophia.inria.fr)
RODEO Project
INRIA Sophia Antipolis
France
Platform: Sun SPARCstation + SunOS 4.1.x + IP
multicast extensions + VideoPix
framegrabber for outgoing video; or
Silicon Graphics Indigo. X windows.
Description: ivs is an integrated audio/video
conferencing tool used in RIPE and
Internet remote conferencing research. A
window is presented to the user giving a
couple of menus, one for selecting a video
encoding and one for selecting an audio
encoding. At the bottom of the window a
list of participants in the conference is
presented and whether each of them is
broadcasting audio or video or both. By
clicking on the buttons next to these
labels you can either hear the audio
through the loud speaker or pop up another
window showing the video image.
The video is encoded using a H.261
software codec. Output from the encoder
is approximately 30 kbyte/s. The audio
stream can be encoded with either PCM (64
kbit/s), ADPCM (32 kbit/s) or VADPCM
(variable rate ADPCM) compression.
Future plans:
Available from: avahi.inria.fr:/pub/videoconference
Price: Free
Standards: H.261, IP multicast
Further information:
Date of entry: 14 December 92
Product name: MacMICAMacMICA
Version:
Manufacturer: Group Technologies
USA
Phone: +1 703 528 1555
Platform: Apple Macintosh
Description: Conferencing system which provides
multipoint, real-time interactive
conferencing between multiple workstations
over Appletalk networks.
Future plans: TCP/IP and PC versions thought to be in
the pipeline.
Available from: Manufacturer.
Price:
Standards:
Further information:
Date of entry: 21 December 1992
Product name: NevotNevot
Current version: 1.01
Manufacturer: Henning Schulzrinne, hgs@research.att.com
AT&T BL
Platform: Sun (SunOS), Silicon Graphics, DEC Ultrix
(soon)
Description: The network voice terminal (NEVOT) allows
audio-capable workstations to participate
in audio conferences across local and wide
area networks. Features:
compatible with NVP (network voice
protocol) as used by 'vat' (LBL) and
VT (ISI)
compatible with 'vat' native packet
format
upward compatible with 'vat' session
protocol
versions for: Sun SPARCstation; SGI
Indigo (4D Series); Personal DECstations
[soon]
GUIs: XView; Motif [in progress];
curses; dumb terminal
can serve as gateway for protocol and
encoding translation
network transport protocols: TCP;
unicast/multicast UDP; ST-2
several independent concurrent
conferences, each with different
encoding and compression
DES-based voice encryption (U.S. only)
audio encodings: 64 kb/s (‘-law PCM); 32
kb/s G.721 ADPCM (Sun only); 32 kb/s
Intel DVI; 24 kb/s G.723 APDCM (Sun
only); 4.8 kb/s LPC codec
each site can use different audio
encodings
playback and recording of AIFC and .snd
audio files
extensive statistics and tracing
facilities
arbitrary voice packet length, which may
differ for each site
lost packet and silence substitution
setable audio buffer occupancy
configurable adjustment mechanisms for
playout delay, VU meter, silence
detector and automatic gain control
redefinable session identifier string
with variable substitution
Future plans: port to other OS; integration of
conference control
Available from: gaia.cs.umass.edu:pub/nevot
Price: Free
Standards: G.711, G.721, G.723, GSM, RTP (v. 1.1)
Further information:
Date of entry: 22 December 1992
Product name: nvnv
Version: 1.6
Manufacturer: Ron Frederick (frederick@parc.xerox.com)
Xerox/PARC
Platform: Sun SPARC, SunOS 4.1.x with IP multicast
extensions, X windows VideoPix
framegrabber + video camera for outgoing
video (not required to receive video)
Description: nv is a videoconferencing tool that
transmits video images across an internet
using UDP/IP. Images maybe sent point-to-
point or can be broadcast to a large
number of receiving stations using
multicast IP. It is widely used in the
DARPA remote conferencing research effort.
An X window with a list of video sources
is presented to the user and video images
to be viewed can be selected by clicking
with a mouse on the label of the
appropriate sending station.
The picture is built up using a slow-scan
method which means that only the changes
between each frame are broadcast.
Typically frame refreshes happen at about
2 to 5 frames per second.
Both PAL and NTSC video standards are
supported.
No specialist hardware is required for
receiving the video image. If video
images are to be transmitted using nv then
a VideoPix framegrabber (available from
Sun Microsystems) and a video camera are
required. There is no integrated audio
support.
Future plans:
Available from: parcftp.xerox.com:/pub/net-research
Price: Free
Standards: IP multicast
Further information:
Date of entry: 14 December 1992
Product name: Person to Person/2Person to Person/2
Version:
Manufacturer: IBM
Platform: PC (386, 16MHz, 12Mb RAM) with OS/2, and
the ActionMedia II Display Adapter with
capture option.
Description: Person To Person/2 is a bilateral
videoconferencing system which
incorporates a shared "chalkboard" window.
The chalkboard can mirror any OS/2
application window, or can be loaded with
bitmaps or scanned images. The chalkboard
can be annotated, and each participant can
see the other's mouse pointer.
Compressed digital video and graphics are
carried either over ISDN, or over a Token
Ring or Ethernet LAN using NetBIOS. There
is an option to carry video over a
physically separate analogue video link.
Voice is carried over the telephone
system.
San Diego Supercomputer Center plan to
study the system and characterize its end-
to-end performance when used across the
Internet. Contact Paul Love
(loveep@sdsc.edu).
The Person To Person/2 software was
developed at IBM Hursley (GB). A lab
version (1.0) has been available since
1991. A new version with OS/2 2.0 support
is due out in early 1993.
Future plans:
Available from: Manufacturer.
Price: 195 (educational discount available)
Standards:
Further information: Mail p2p@vnet.ibm.com
Date of entry: 21 December 1992
Product name: PICFONPICFON
Version:
Manufacturer: Specom Technologies Ltd
3673, Enochs Street,
Santa Clara
CA 95051
USA
Phone: +1 408 736 7832
Platform: PC
Description: PC-based video telephone system which uses
a 14.4 kbit/s modem. Video is captured and
compressed using the CAPICOM board and
transmitted using the PICFON card.
Future plans:
Available from: Manufacturer.
Price:
Standards:
Further information:
Date of entry: 21 December 1992
Product name: sdsd
Version: 1.8
Manufacturer: Van Jacobson
Lawrence Berkeley Laboratory
Berkeley
California
USA
Platform: Sun SPARCstation + SunOS 4.1.x + IP
multicast extensions, X windows
Description: This is a session director. It lists all
the audio/video conferences available on
the Internet. Information about each
conference (what it is, who created it,
when it starts and finishes, which address
and conferencing protocol it uses) is
presented to the user.
When the user selects the desired
conference from the list, the appropriate
tool is started (eg. nv or vat) with the
correct address and port number for that
conference.
A facility for creating conferences is
provided and these conferences can be
limited to being site-wide, region-wide,
or global. This is currently achieved by
setting the time-to-live on the broadcast
packets.
This tool is being developed as part of
the DARPA remote conferencing research
effort.
Future plans: Ongoing development of the tool and
underlying protocols.
Available from: ftp.ee.lbl.gov
Price: Free
Standards: IP Multicast
Further information:
Date of entry: 14 December 1992
Product name: ShowMeShowMe
Version: 1.0
Manufacturer: SunSolutions (Sun Microsystems)
MTV02-208 2550 Garcia Avenue
Mountain View
CA 94043
USA
Fax: +1 415 962 9421
Platform: Any SPARC architecture based system
running Solaris 1.0 or higher.
Description: ShowMe is a computer conferencing tool.
Virtually any information that would be
presented or recorded in a conference room
can be interactively presented to that
same group from the desktop using this
software.
ShowMe supports global workgroups
connected via any TCP/IP based local or
wide are network. Conferees can import
information from their desktop such as
slide presentations, documents, graphs,
images, and spreadsheets onto ShowMe's
shared conference board, and then augment
their verbal discussion visually and
interactively using ShowMe's on-screen
markers to gesture or mark-up the
information. With the Active Window
feature you can make changes to your
applications and then pop these changes
onto the ShowMe conference board for
further discussion.
Voice is carried over the normal telephone
network.
ShowMe was released in September 1992.
Future plans: Support for additional hardware platforms
and operating systems is planned.
Available from: Manufacturer.
Price:
Standards:
Further information:
Date of entry: 18 January 1993
Product name: SlateSlate
Version:
Manufacturer: BBN
Platform: UNIX workstations
Description: Slate provides real-time conferencing and
multimedia electronic mail on UNIX
workstations. Slate allows shared access
of documents (images, desktop
publications) in real time. It's all based
around a mail system so that there's a
natural archival system for the various
sorts of media being shared.
Future plans: Investigations into the use of (Internet-
compatible) videoconferencing facilities
within Slate are proceeding at BBN.
Available from: Manufacturer.
Price: Slate is available to educational sites
(at least in the US) at $100 a license
(site licenses are also available).
Standards:
Further information: Pam Gazley (pgazley@bbn.com)
Date of entry: 22 December 1992
Product name: vatvat
Version: 1.55
Manufacturer: Van Jacobson
Lawrence Berkeley Laboratory
University of California
Berkeley
CA
USA
Platform: Sun SPARCstation, SunOS 4.1.x + IP
multicast extensions, X windows
Description: vat is an audio-conferencing tool which
supports both point-to-point and
broadcasting of audio using multicast IP.
This tool is extensively used in the DARPA
remote conferencing research effort.
A window is presented to the user showing
a list of names of all the participants of
the conference. The tool allows you to set
the gain on the microphone and
loudspeaker. You can select whether the
audio received goes to the loudspeaker or
headphones. You can select individual
members of the conference and either setup
a side-conversation with them or block out
the audio coming from that station.
Different audio encodings are supported:
pcm 64Kb/s 8-bit ‘-law encoded 8KHz PCM
idvi 32Kb/s Intel DVI ADPCM
gsm 16Kb/s GSM
lpc1 18Kb/s Linear Predictive Coder
lpc4 8Kb/s Linear Predictive Coder
vat can act as a filter between these
different formats.
Encryption of audio data using DES is
supported, thought there is no automatic
way of propagating/generating the
encryption key.
Future plans: Work is underway on U.S. Federal Standard
1016 4800 bit/s CELP (a very low bandwidth
codec that could be run over 9600 baud
dial-up SLIP links).
Available from: ftp.ee.lbl.gov (binary only).
A source distribution has been promised
for the future.
Price: Free
Standards:
Further information:
Date of entry: 14 December 1992
Product name: VC7000VC7000
Version:
Manufacturer: Tandberg Telecom
Platform: PC
Description: Videoconferencing system and document
transmission system. Conforms to H.261
coding. Audio is synchronised to full
motion video.
Future plans:
Available from: British Telecom
81, Newgate Street
London
EC1A 7AJ
Great Britain
Phone: +44 800 515 550
Price:
Standards: H.261, G.722
Further information:
Date of entry: 21 December 1992
Product name: VCI/oemVCI/oem
Version:
Manufacturer: VistaCom
Tietajantie 14
02130 Espoo
Finland
Phone: +358 0 460 099
Fax: +358 0 460 610
Platform: PC
Description: VCI/oem is a set of H.261 video codec
boards for the OEM market, designed for
use over a number of different network
types with bandwidths from 56 kbit/s up to
2 Mbit/s. A JPEG compression option is
available.
The basic video codec consists of two
PC/AT bus boards. Six additional boards
are available for various networks
interfaces.
There is a development kit, called CDS-
261/100, which consists of one set of all
codec boards, one fully assembled and
tested codec in a standalone chassis,
development software and technical
manuals. A 3-day course is also
available.
The products were released in October
1992.
Future plans:
Available from: Manufacturer.
Price:
Standards: H.261, H.221, H.241, H.200/AV.254
Further information: Mr. Rolf Vainio
VP International Sales
VistaCom
Date of entry: 21 December 1992
Product name: VS1000VS1000
Version:
Manufacturer: Mentec International Ltd
Mentec House
520 Birchwood Boulevard
Birchwood
Warrington
WA3 7QX
Great Britain
Phone: +44 925 830000
Platform: MS Windows
Description: Videoconferencing system for MS Windows. A
codec card, screen window update card and
camera are required.
Future plans: JPEG, MPEG, SUN
Available from: Manufacturer.
Price: 10,000
Standards: H.261, G.711
Further information:
Date of entry: 21 December 1992
Product name: Communique[Communique]
Manufacturer: InSoft
Description:
Product name: Desktop Videoconferencing[Desktop
Videoconferencing]
Manufacturer: Fujitsu Networks Industry
Description: ISDN-based desktop videoconferencing for
MS Windows
Product name: mmcc[mmcc]
Manufacturer: ISI
Description: Runs on Sparcs over the DSI network (ST-
1.5). It's a video conferencing tool used
in research. Contact Eve Schooler
(schooler@venera.isi.edu) for more info
about it.
Product name: ShareVision[ShareVision]
Manufacturer: ShareVision
Description: Desktop videoconferencing and real-time
document sharing over POTS lines for
Macintosh
Product name: VISIT Video[VISIT Video]
Manufacturer: Northern Telecom
Description: Desktop videoconferencing via switched-56
or ISDN for Apple Macintosh and IBM PC.
It integrates desktop video conferencing,
screen sharing, electronic voice mail.
Product name: MAEstroMAEstro
Manufacturer: Stanford University
Platform: Sun and NeXT workstations
Description: MAEstro is a distributed multimedia
authoring environment. It is designed for
a scenario where multimedia devices such
as audio CD, videodisk, MIDI interface and
text display are located on separate
networked workstations. A multimedia
presentation is "played back" by the
authoring application, which remotely
controls each media device using RPC .
This approach therefore avoids the
difficult problem of transporting
multimedia data across the network.
MAEstro lets workstation users create
multimedia presentations combining text,
CD music, video, digitised audio, and
processes launched with UNIX shell
commands. Each of these media has an
associated application, called a media
editor, used to operate the media player
and to select material for the
presentation.
Once the material has been selected, it is
organised into a presentation using the
TimeLine editor. This editor is the heart
of the system - it lets the user visually
lay down media selections in relation to
each other and synchronise their playback.
The approach of using individual editors
for each medium allows new media to be
added to the system very easily.
Future plans:
Available from: sioux.stanford.edu:/pub/MAEstro
and numerous other FTP archive sites.
Price:
Standards:
Further information: See "MAEstro - A Distributed
Multimedia Authoring Environment", G.
Drapeau and R. Greenfield, Multimedia for
Now and the Future, Usenix Conference
Proceedings, June 1991.
There is a mailing list:
maestro@sioux.stanford.edu.
Date of entry: 30 November 1992
Product name: MetamailMetamail
Version:
Manufacturer: Bellcore
Platform: UNIX, DOS, Commodore Amiga
Description: Metamail is a package that can be used to
convert virtually ANY mail-reading program
(on UNIX, DOS, or Commodore Amiga) into a
multimedia mail-reading program. It is an
extremely generic implementation of MIME
(Multipurpose Internet Mail Extensions),
the proposed standard for multimedia mail
formats on the Internet. The
implementation is extremely flexible and
extensible, using a "mailcap" file
mechanism for adding support for new data
formats when sent through the mail. At a
heterogeneous site where many mail readers
are in use, the mailcap mechanism can be
used to extend them all to support new
types of multimedia mail by a single
addition to a mailcap file.
The core of the package is a mechanism
that allows the easy configuration of mail
readers to call external "viewers" for
different types of mail. However, beyond
this core mechanism, the distribution
includes viewers for a number of mail
types defined by the MIME standard, so
that it is useful immediately and without
any special site-specific customisation or
extension. Types with built-in support in
the metamail distribution include:
Plain US ASCII (ie, English) text, of
course.
Plain text in the ISO-8859-8
(Hebrew/English) character set.
Richtext (multifont formatted text,
termcap-oriented viewer)
Image formats (using the xloadimage
program under X11)
Audio (initial "viewer" for
SPARCstations)
Multipart mail, combining several other
types
Multipart/alternative mail, offering
data in multiple formats.
Encapsulated messages
Partial & external messages (for large
data objects)
Arbitrary (untyped) binary data
Other media types and character sets may
be easily supported with the mailcap
mechanism, using the provided types as
examples/templates. The metamail software
also provides rudimentary support for the
use of non-ASCII characters in certain
mail headers, as described by a companion
document to the proposed MIME standard.
The metamail distribution comes complete
with a small patch for each of over a
dozen popular mail reading programs,
including Berkeley mail, mh, Elm, Xmh,
Xmail, Mailtool, Emacs Rmail, Emacs VM,
Andrew, and others. Crafting a patch for
additional mail readers is relatively
straightforward.
In order to build the metamail software, a
single "make" command followed by a
relatively short compilation will suffice.
Patching your mail reader is somewhat
harder, but can usually be accomplished in
less than an hour if you have the sources
at hand. The experience of beta testers
is that the metamail package can easily be
used to get multimedia mail working with
your existing mail readers in less than
half a day.
Future plans:
Available from: thumper.bellcore.com:pub/nsb
The distribution is mirrored in Europe on
the following sites:
src.doc.ic.ac.uk:mail/metamail
ftp.funet.fi:/pub/unix/mail/metamail.
Price: Free
Standards: MIME
Further information: Sample MIME-format messages,
documentation and other information are
separately available at the above FTP
sites. There is a mailing list:
INFO-METAMAIL@thumper.bellcore.com.
Date of entry: 30 November 1992
Product name: MS MailMS Mail
Current version: 3.0
Manufacturer: Microsoft
Platform: PC with Windows and DOS.
Description: PC LAN-based email system with support for
multimedia attachments through the use of
OLE (Object Linking and Embedding). This
allows a document to be displayed within
the Mail program's window by the
application which originated the document.
There are a number of competing PC LAN-
based mail products which also offer some
form of multimedia capability, such as
BeyondMail, DaVinci Combo and Finansa
WinMail. These products also compete
against MIME-based PC mail programs such
as Unipalm's Mail-IT.
Future plans: Microsoft are believed to be enhancing
their X.400 gateway product to transport
multimedia (and other) document types as
X.400 body parts. No information is
available about the object identifiers,
parameters etc which the gateway will
employ to carry MS Mail's documents in
X.400 body parts.
Available from: Manufacturer.
Price: 485 for 10 users.
Standards: X.400
Further information:
Date of entry: 20 January 1993
Product name: NotecardsNotecards
Version:
Manufacturer: Xerox PARC
Platform: SUN, PC, X windows
Description: A tool for co-ordinating the work of a
number of workers, using linked index
cards. There is built-in support for text,
graphics, animation and video, as well as
links to external programs. LISP is the
underlying language.
Future plans:
Available from: Artificial Intelligence Ltd
Greycaine Rd
Watford
Herts
WD2 4JP
Great Britain
Phone: +44 442 876722
Price: 500
Standards:
Further information:
Date of entry: 21 December 1992
Product name: NotesNotes
Current version: 2.1
Manufacturer: Lotus Development Corporation
55 Cambridge Parkway
Cambridge
MA 02142
USA
Platform: IBM PC running Windows 3.1 or OS/2 1.x.
An OS/2 machine is required as a server.
Description: A network database system in which the
database can contain both a fixed set of
data types (eg plain text, rich text,
graphics, switches, toggles, etc) and
arbitrary data in the form of attachments
(eg sound files, executable programs,
etc). The database can be replicated
across phone lines, LANs (using NetBIOS,
Banyan Vines, SPX, etc), and X.25, among
other, with gateways to VMS and UNIX
(minus the multimedia support).
The system is flexible enough to be user
for e-mail, discussion groups, news
distribution, graphics archives, etc.
Future plans: The next release, 3.0, will additionally
support Macs, OS/2 2.0, and UNIX platforms
(Sun, IBM, SCO, HPUX), and TCP/IP.
Available 1993.
Available from: Manufacturer
Price:
Standards:
Further information: There are Notes users groups
around, including a just-formed group,
WALNUT (Worldwide Association of Lotus
Notes Users and Technologists).
Date of entry: 18 December 1992
Product name: PACoPACo
Version:
Manufacturer: Company of Science and Art
14, Imperial Place
Suite 203,
Providence, RI
USA
Phone: +1 401 831 2672
Email: cosa@applelink.apple.com
Platform: Apple Macintosh, MS Windows, X windows
Description: A software-only compression and playback
system for presenting digital videos,
animations and sound. Allows QuickTime
movies to be converted to a form which can
be played back on PCs (MS Windows) and
UNIX machines (X windows). The system is
made up of a number of modules, including
players and producers.
Future plans:
Available from: Manufacturer.
Price:
Standards:
Further information:
Date of entry: 21 December 1992
Product name: StarWorksStarWorks
Version:
Manufacturer: Starlight Networks Inc
444 Castro St
Suite 301
Mountain View
CA 94041
USA
Phone: +1 415 967 2774
Fax: +1 415 967 0686
Platform: 50MHz 486-based PC with UNIX
Description: StarWorks digital video networking
software provides network delivery and
applications services for stored and/or
live streaming data such as video, audio
and other multimedia data types.
The Starlight MediaServer is a dedicated
hardware and software package which
functions as a video server. PC and
Macintosh clients can retrieve video and
audio data from the MediaServer. The
software component of the MediaServer is
StarWorks.
The MediaServer contains several Ethernet
cards, to provide sufficient bandwidth to
allow it to support multiple video
clients. Connection between the client
and MediaServer is either direct Ethernet
(with clients appropriately distributed
between the multiple Ethernets), or
alternatively using an Ethernet "switched
hub", with each client individually
connected in a star configuration to the
hub, and the multiple Ethernet interfaces
in the MediaServer also connected to the
hub.
StarWorks is based on a real-time UNIX
variant. It has three key management
services:
Stream Management. This component
manages the connections between data
stream producers (eg disk store, video
cameras, etc) and data stream consumers
(eg client station displays, disk store,
etc). This service is responsible for
ensuring that sufficient bandwidth is
available for a requested connection.
Multiple streams up to a total bandwidth
of 25Mbit/s are supported - for instance
up to 20 simultaneous sessions using DVI-
encoded video at 1.2 Mbit/s. A stream
may also be broadcast. StarWorks is
independent of the video encoding
format, so DVI, JPEG, MPEG can be used
in different streams up to 25 Mbit/s.
Object management. An "object"
comprises multiple "tracks" of data.
For example, multiple sound tracks can
be associated with the same video data
and can be dynamically associated for a
given user. It is also possible for
unmodified client applications which
assume that video is stored in a local
file to transparently access video via
StarWorks.
Storage management. In the StarWorks
architecture, Winchester disk drive
arrays - using a proprietary "Streaming
RAID" data striping algorithm - are used
as the primary storage medium. The
StarWorks storage manager organises the
video on the disk array in a manner
optimised for the available bandwidth,
so that large number of users can
simultaneously access the data.
Different users can access different
videos; can start the same video at the
same time, or can access the same video
within seconds of each other.
The StarWorks video networking interface
software on the client provides dynamic
control of the StarWorks services (stream,
object and storage management) via a
proprietary Media Transport Protocol. MTP
is based on the experimental XTP protocol
developed in the high speed networking
research community. It coexists in the
client alongside other protocols such as
Appleshare, NFS, NetWare.
Future plans:
Available from: Manufacturer.
Price: $23,500 (10-user) / $39,500 (20-user)
Standards:
Further information: There is a short descriptive
article in Data Communications, p37,
October 1992.
Date of entry: 10 December 1992
Product name: XanaduXanadu
Version:
Manufacturer: Xanadu Operating Company
550, California Street
Palo Alto
CA 94306
USA
Platform:
Description: Xanadu is working on a hypermedia database
server. It will support "open, social
hypermedia". The database will support
text, bitmaps, sound, video, and animation
as well as links between them all at
whatever granularity is desired: from a
character or pixel to a whole library.
Some of the implications of supporting
open, social hypertext are that:
multiple users can simultaneously edit
documents
links continue to connect to the same
things even as the documents at the ends
of the link evolve
you can install detectors on documents
that will notify you when the documents
are modified or linked to
supports links to information that is
stored outside the Xanadu repository (eg
WAIS and WWW)
The project has a long and colourful
history, starting with Ted Nelson coining
the terms "hypertext" and "hypermedia" in
1965 or so. You can read his recently
reissued book, "Computer Lib/Dream
Machines" to find out about his original
conception for the global hypertext
publishing system. (It's available from
Microsoft Press.) What Xanadu is actually
building at this point is only a part of
Ted's original conception, though it's
designed to be the first stepping stone to
the whole thing. The project has been
around for quite a while, and has reported
being nearly done many times.
Xanadu are building a hypermedia storage
server; the database engine. It will
require a separate FrontEnd, or User
Interface, in order to be useful. Xanadu
will provide one such FrontEnd, but want
other developers to build a variety of
application-specific FrontEnds to exploit
their work in many different fields. They
hope to see Xanadu applications in CASE,
CAD, CAE, Medical data storage, legal
office, group work, image retrieval and
manipulation, and many other fields.
Future plans:
Available from:
Price:
Standards:
Further information: Chris Hibbert
(hibbert@xanadu.com)
Date of entry: 22 December 1992
Product name: XMedia ToolsXMedia Tools
Current version: 1.1
Manufacturer: DEC
Platform: MIPS/Ultrix (DECStation line)
Description: XMedia Tools is audio/video enabling
software which assists software developers
in building distributed multimedia
applications, or adding audio/video
components to existing applications or
documentation. It includes an Audio/Video
Runtime Kit and an Audio/Video Developer
Kit. The product was released in January
1992.
The Audio/Video Runtime Kit includes on-
line documentation, drivers, servers,
sample applications, the Software Motion
Pictures compiler and a few sample audio
and video clips. This is used to run audio
and video applications or play sample
audio and video clips.
The Audio/Video Developer Kit adds more on-
line documentation, audio and video
libraries, a more extensive audio clip
library, and tools, to the functionality
found in the Runtime Kit. This is used to
develop applications which use audio and
video functionality.
Audio/Video Runtime Kit. Audio and Video
Drivers provide support for the DECaudio
and DECvideo TURBOchannel options as well
as the built-on audio in the Personal
DECstation 5000.
The Audio Server allows multiple audio
events, eg, music, sound effects and
recorded speech to occur simultaneously.
Its synchronisation primitives allow
commands and devices to be sequenced. It
also manages audio resources among
different clients. The Audio Server
supports both DECaudio and the Personal
DECstation 5000's audio capabilities.
The Xv Video Extension to the X Server
allows live video to be displayed in a
workstation window. The DECvideo
TURBOchannel option can convert a channel
of analog video into a digital format
(uncompressed) for display on a
workstation. The extension attaches the
digitized video frame to a user-specified
window and allows sharing of the screen
between the video window and other
windows.
Software Motion Pictures (SMP) is a method
used to compress, transmit, and decompress
a sequence of digitized video frames
across the network. SMP is useful when you
want to display video in an environment
that does not permit the installation of
additional hardware. SMP clip convenience
functions allow you to store and retrieve
SMP data to and from your file system.
SMP allows you to exercise frame-level
control over sequences of digitized video
images displayed on X Window System-based
workstations. Because SMP displays
individual frames very quickly under
program control, it is a simple matter to
search for specific frames, to play
backwards or at high speed, or otherwise
to sample through portions of a pre-
recorded video sequence.
SMP images are stored digitally as data
files either on your workstation's local
disk or on a file server on the network.
You do not need to manage the images on a
series of external devices as you do with
analog video. Managing the video files
for your application can be done as you
would manage any set of data files for an
application with large quantities of data
in storage.
Audio/Video Developer Kit. The Audio
Library (Alib) provides the interface to
the Server protocol. The audio toolkit
provides several Motif widgets and utility
functions that interface X programs to
audio. Software Motion Pictures Builder
includes a compiler, utilities and an X
toolkit widget. The compiler compresses
digital frames into Software Motion
Pictures format. The Software Motion
Pictures widget decompresses and displays
clips in an X window. Software Motion
Pictures frames can also be exported to
DDIF files.
Future plans: Availability of digital video component
(Software Motion Pictures) on other
platforms.
Available from: Manufacturer.
Price: $300 for license, usually bundled with
some multimedia hardware to go with it.
Standards:
Further information: Burkhard Neidecker-Lutz
(neideck@nestvx.enet.dec.com),
or ask in newsgroup biz.dec.xmedia
Date of entry: 14 December 1992
Product name: WhiteMailWhiteMail
Version: 1.1
Manufacturer: Edinburgh University Computing Service
Main Library Building
George Square
Edinburgh
EH8 9LJ
Great Britain
Platform: 386 PC, 4 Mb RAM, MS Windows
Description: WhiteMail is an X.400 Mail User Agent
which uses the P7 protocol to communicate
with an X.400 Message Store. At present
it runs under MS Windows, but a character-
mode DOS version is in preparation.
WhiteMail supports graphical (one
bit/pixel) message body parts, using the
Group 3 Fax encoding according to the
X.400 standard. Facilities are provided
to convert to and from BMP and TIFF files.
Future plans: Support for OLE (Object Linking and
Embedding) will be added in a future
version of WhiteMail, allowing arbitrary
document types (eg colour graphics, video,
sound) to be sent and received.
Available from: Manufacturer.
Price: WhiteMail itself is free to the
international academic community (but see
below). It is not public domain, and non-
academic institutions have to buy a
licence for each copy.
In order for WhiteMail to function, it
requires a separate OSI stack. The
recommended OSI stack is called
WhiteStack, but the cost of WhiteStack is
prohibitive. EUCS is seeking ways to
reduce this cost.
Standards: X.400(88)
Further information: Pat Moran
(P.Moran@edinburgh.ac.uk)
Chris Adie (C.J.Adie@edinburgh.ac.uk)
Date of entry: 14 December 1992
Product name: HyMinder[HyMinder]
Manufacturer: TechnoTeacher
Description: HyTime engine. See HyTime entry in
Standards section for the address of
TechnoTeacher.
5. Wide-Area Information Servers
Gopher 148
WAIS 149
WWW 151
Name: GopherGopher
Category: University-led initiative
Funding body: none
Participants: University of Minnesota (originators) (US)
many other University sites
Summary: Simple front-end to a range of Internet
resources.
Description: The Internet Gopher is a distributed
document delivery service. It allows a
neophyte user to access various types of
data residing on multiple hosts in a
seamless fashion. This is accomplished by
presenting the user with a hierarchical
arrangement of documents and by using a
client-server communications model. The
Internet Gopher Server accepts simple
queries, and responds by sending the
client a document.
Clients are available for a large number
of systems, including:
UNIX (character terminals)
X windows
Apple Macintosh
MS DOS
NeXT
VM/CMS
VMS
OS/2
MVS/XA
Servers are available for systems such as:
UNIX
VMS
Apple Macintosh
VM/CMS
MVS
MS DOS
Some implementations now support viewing
of GIF images.
Further information: FAQ from:
pit-
manager.mit.edu:/pub/usenet/news.answers
Newsgroup: comp.infosystems.gopher.
Software and further information:
boombox.micro.umn.edu:/pub/gopher
Contact point: Internet Gopher Developers
(gopher@boombox.micro.umn.edu)
100 Union St. SE #190
Minneapolis
MN 55455
USA
Fax: +1 612 625 6817
Name: WAIS (Wide Area Information Server)WAIS
Category: Vendor-led initiative
Funding body: Funded by participants.
Participants: Several vendors, including:
Thinking Machines (US)
Apple Computer (US)
Dow Jones (US)
Summary: The WAIS project is an experiment,
automating the search for and retrieval of
many types of electronic information over
wide area networks.
Description: The Wide Area Information Server system is
a set of products supplied by different
vendors to help end-users find and
retrieve information over networks.
Thinking Machines, Apple Computer, and Dow
Jones initially implemented such a system
for use by business executives. These
products are becoming more widely
available from various companies.
Users on different platforms can access
personal, company, and published
information from one interface. The
information can be anything: text,
pictures, voice, or formatted documents.
Since a single computer-to-computer
protocol is used, information can be
stored anywhere on different types of
machines. Anyone can use this system
since it uses natural language questions
to find relevant documents. Relevant
documents can be fed back to a server to
refine the search. This avoids
complicated query languages and vendor-
specific systems. Successful searches can
be automatically run to alert the user
when new information becomes available.
The servers take a user's question and do
their best to find relevant documents.
The servers, at this point, do not
"understand" the user's English language
question, rather they try to find
documents that contain those words and
phrases and ranks then based on
heuristics. The user interfaces (clients)
talk to the servers using an extension to
a standard protocol Z39.50. Using a
public standard allows vendors to compete
with each other, while bypassing the usual
proprietary protocol period that slows
development. Thinking Machines is giving
away an implementation of this standard to
help vendors develop clients and servers.
Further information: Public-domain WAIS software for
a range of machines is available from:
quake.think.com:/pub/wais. There is much
WAIS information, including papers and
reports at this site.
There is a mailing list that has weekly
postings on progress and new releases:
wais-interest@think.com, and another for
general WAIS matters: wais-
discussion@think.com
Contact point: Brewster Kahle (Brewster@think.com)
Project Leader, Wide Area Information
Servers
Thinking Machines
1010 El Camino Real
Suite 310
Menlo Park
CA 94025
USA
Phone: +1 415 329 9300
Fax: +1 415 329 9329
Name: WWW (World-Wide Web)WWW
Category: User-driven initiative
Funding body: No official funding, all volunteer work.
CERN has funded two people for High-Energy
Physics related activity. Most other work
is done in US. Funding required for the
next phase.
Participants: Unofficial participation from members of
CERN, SLAC, Boston University, Convex Inc,
NCSA, CWI Amsterdam, etc.
Commenced: 1990
Summary: Global hypermedia system incorporating all
forms of information in seamless world
view.
Description: The WWW project merges the techniques of
information retrieval and hypertext to
make an easy-to-use but powerful global
information system.
The project is based on the philosophy
that much academic information should be
freely available to anyone. It aims to
allow information sharing within
internationally dispersed teams, and the
dissemination of information by support
groups. Originally aimed at the High
Energy Physics community, it has spread to
other areas and attracted much interest in
user support, resource discovery and
collaborative work areas.
Reader View
The WWW world consists of documents, and
links. Indexes are special documents
which, rather than being read, may be
searched. The result of such a search is
another ("virtual") document containing
links to the documents found. A simple
protocol ("HTTP") is used to allow a
browser program to request a keyword
search by a remote information server.
The web contains documents in many
formats. Those documents which are
hypertext, (real or virtual) contain
links to other documents, or places within
documents. All documents, whether real,
virtual or indexes, look similar to the
reader and are contained within the same
addressing scheme.
To follow a link, a reader clicks with a
mouse (or types in a number if he or she
has no mouse). To search and index, a
reader gives keywords (or other search
criteria). These are the only operations
necessary to access the entire world of
data.
Information Provider View
The WWW browsers can access many existing
data systems via existing protocols (FTP,
NNTP) or via HTTP and a gateway. In this
way, the critical mass of data is quickly
exceeded, and the increasing use of the
system by readers and information
suppliers encourage each other.
Making a web is as simple as writing a few
SGML files which point to your existing
data. Making it public involves running
the FTP or HTTP daemon, and making at
least one link into your web from another.
In fact, any file available by anonymous
FTP can be immediately linked into a web.
The very small start-up effort is designed
to allow small contributions.
At the other end of the scale, large
information providers may provide an HTTP
server with full text or keyword indexing.
This may allow access to a large existing
database without changing the way that
database is managed. Such gateways have
already been made into Digital's VMS/Help,
Technical University of Graz's "Hyper-G",
and Thinking Machine's WAIS systems.
The WWW model gets over the frustrating
incompatibilities of data format between
suppliers and reader by allowing
negotiation of format between a smart
browser and a smart server. This should
provide a basis for extension into
multimedia, and allow those who share
application standards to make full use of
them across the web.
The protocol is currently being
implemented to add multimedia facilities.
Existing standards are used wherever
possible, notably in the use of SGML for
hypertext format, MIME registration for
multimedia representations, and internet-
style telnet basis for the search/retrieve
protocol.
Platform: There is browser software for use with:
Line-mode dumb terminal.
Terminal with Curses support
Macintosh
X/Motif
X11
NeXT
There is server software available for:
VM mainframes.
UNIX
VMS
Products: There are many compatible products.
Papers/reports: "World-Wide Web: The Information
Universe", T. J. Berners-Lee et. al.,
CERN, published in "Electronic Networking:
Research, Applications and Policy", Vol. 2
No 1, pp. 52-58 Spring 1992, Meckler
Publishing, Westport, CT, USA.
"World-Wide Web: An Information
Infrastructure for High-Energy Physics",
T. J. Berners-Lee et. al., CERN, Presented
at "Artificial Intelligence and Software
Engineering for High Energy Physics" in La
Londe, France, January 1992. Proceedings
to be published by World Scientific,
Singapore, ed. D Perret-Gallix.
Further information: The line mode browser is
currently available by anonymous FTP from:
info.cern.ch:/pub/www
The above papers and other information may
be available by FTP at the same place, or
via the Web itself.
Contact point: Tim Berners-Lee (timbl@info.cern.ch)
Appendix 1: RARE Multimedia Working Group
The RARE Multimedia Working Group has a charter which
includes the following objectives:
To act as a focus for user requirements for emerging
technology.
To promote standards which allow the inter-operation of
multimedia services across open networks.
To act as a forum for discussion between developers,
users and service providers about requirements and
quality.
To act as a catalyst in the development of new
applications.
The scope of the group includes:
Video/audio conferencing over computer networks.
Multi-party collaborative working.
Delivery of video output from supercomputers.
Multimedia-enhanced communications applications (such
as multimedia mail).
Further information is available by sending a mail
message to mailserver@rare.nl containing in the body the
message INFORMATION WG-IMM.
There is a mailing list which anyone is free to join.
The address is wm-imm@rare.nl. To subscribe, send a mail
message to mailserver@rare.nl containing in the body the
message SUBSCRIBE WG-IMM.
Working Group chair: John Dyer (J.Dyer@jnt.ac.uk)
Joint Network Team
c/o Rutherford Appleton Laboratory
Chilton
Didcot
OX11 0QX
Great Britain
Phone: +44 235 445433
Fax: +44 235 446251
Appendix 2: Obtaining Standards Documents
RFCs
RFCs may be obtained from several sources on the
Internet. You should access the source nearest to you.
In Europe, a suitable source is:
nic.funet.fi:pub/doc/rfc.
CCITT Recommendations and ISO standards
Paper copies of these documents are available for sale
from the following company:
Omnicom PPI Ltd
Forum Chambers
The Forum
Stevenage
Herts
SG1 1EL
Great Britain
Phone: +44 438 742424
Fax: +44 438 740154
ITU Teledoc server
Many CCITT Recommendations are now available either in
full or in summary form on a mailserver. For information
on accessing this server, send a mail message to:
teledoc@itu.arcom.ch with HELP in the body of the
message. For further information about the service,
contact:
Robert Shaw (shaw@itu.arcom.ch)
TELEDOC Project Co-ordinator
Information Services Department
Place des Nations
1211 Geneva 20
Switzerland
Phone: +41 22 730 5338/5554
Fax: +41 22 730 5337
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