News
| Date | 01 January 1985 |
| Published date | 01 January 1985 |
| DOI | https://doi.org/10.1108/eb044637 |
| Pages | 8-26 |
| Subject Matter | Information & knowledge management,Library & information science |
news
GENERAL
Meckler acquires
Micro Software Reports
and Micro Software Evaluations
Meckler Publishing has announced the acqui-
sition of Micro Software
Reports
and Micro
Soft-
ware Evaluations from Nolan Information
Management Services of Torrance, California.
Alan M. Meckler, President of Meckler Pub-
lishing, stated that "Micro Software
Reports
is
the world's largest and most comprehensive
index to microcomputer software with specific
library applications". He went on to say that
"the publication indexes 110 library and com-
puter oriented journals concentrating on infor-
mation that includes pricing, installation
locations and complete system descriptions".
The other part of the acquisition, Micro
Soft-
ware Evaluations, presents over forty evalu-
ations of library software conducted by library
professionals who are actually using the pro-
grams under review. Meckler pointed out that
each evaluation includes "sample screens and
printouts, in-depth descriptions, samples of
applications, discussion of documentation,
ease-of-use, support, and size limitation".
The 1984/1985 edition of
Micro
Software Re-
port was pubished in December 1984, price
$97.50.
Meckler Publishing is a publisher of library-
oriented software and computer publications.
For additional information contact Angela
Suter, Meckler Publishing, 11 Ferry Lane
West, Westport, CT 06880, USA.
Apollo* system requirements
System description
The Apollo concept was elaborated as a system
for electronic delivery of documents from
document archives to remote users such as
libraries and documentation centres. The orig-
inal concept has been broadened to be appli-
cable to a wider range of applications requiring
the transmission of long data messages similar
to digital facsimile images of documents.
The satellite transmission system of Apollo
is a store-and-forward high-speed digital trans-
mission system specially designed to handle
long data
messages.
The system
will
use a high-
speed digital carrier in the ECS part of the
Satellite Multiservice System (ECS/SMS) of
Eutelsat.
Only information which, because of its char-
acteristics, would require or benefit from the
capabilities of the satellite link, should be
transmitted through the satellite. Signals such
as information orders, retransmission re-
quests, etc. should be routed
via
terrestrial net-
works connecting data stations communicating
through the
satellite.
Hence, the terrestrial and
the satellite networks will be used in an inte-
grated but complementary manner.
The information sources in the system will
be connected via digital terrestrial lines to
transmit earth stations. These stations could be
shared with other applications of the ECS/SMS
system. Information sinks receiving data from
the satellite will be connected to receive earth
stations.
The satellite transmission system should be
compatible with the use of small receive-only
earth stations sited near or on the premises of
the users of the system. However, this does not
exclude or prevent reception at shared ECS/
SMS earth stations where the data stations
would be distant from the earth station and
connected by digital terrestrial lines.
In order to time-share the use of the same
carrier in the ECS/SMS satellite repeater
between several transmit earth stations, a
demand-assigned sequential satellite access
system is required to ensure that transmissions
from different earth stations do not collide at
the input to the satellite repeater. This feature
of the satellite access system makes it compati-
ble with the Single Channel Per Carrier (SCPC)
arrangement in the ECS/SMS system as well as
with the use of small low-cost receive-only
earth stations.
The Apollo system will be capable of serving
applications requiring the transfer of large
volumes of binary information. The system
will be especially suited for the transmission of
information from large central information
*Article Procurement with On-Line Local
Ordering
8 The Electronic Library, January 1985. Vol. 3, No. 1.
sources to remote users requesting information
through terrestrial networks. An important
application of this type would be the electronic
delivery of documents from document
archives. The remote users would order docu-
ments either directly from the archives via
terrestrial networks, or via bibliographic data-
bases providing document references online to
remote users while the records of documents
requested would be delivered through the
satellite.
Examples
of
potential Apollo applications
The following examples of applications have in
common that the amount of binary infor-
mation exchanged during one transaction is
very large. This makes these applications
possible candidates for the Apollo transmission
system:
— delivery of digital facsimile records of docu-
ments
— bulk delivery of text documents
— page facsimile transmissions (remote print-
ing of newspapers, journals and other
periodicals)
— electronic post (e.g. 'Intelpost' types of
ap-
plications)
— computer data file transfer (electronic
delivery of magnetic tapes or the contents
of
disk and other computer memories)
— (multidestination) database distribution
— transfer of images generated in the context
of high-resolution computer graphics
systems
— electronic delivery of data acquired from
earth observation satellites (meteorological
and earth-resource images of the earth).
For a document delivery service using the
Apollo system, there are four distinct func-
tional components, which need to be inter-
connected in order to place requests for and to
deliver the documents. These components are:
the
document
terminal,
from which the requests
are sent and to which the documents are
delivered; the online bibliographic index,
through which the user searches subject cata-
logues to ascertain information about docu-
ments relating to the subject of interest; the
document
archive,
which contains the document
being ordered and from where the document is
dispatched to the document terminal(s) of the
user(s);
and the
transmission
system,
this being
the satellite network for the dispatch of docu-
ments and the terrestrial network for the
search of bibliographic indexes, document
ordering, etc.
Possible modes of operation for a document
ordering and delivery service are:
— where documents are sent from archives to
document terminals via the satellite without
prior request.
— where a user has prior knowledge of the
contents of an archive and accesses it direct-
ly by means of the post, telex, facsimile,
data service, etc. in order to place an order
for a document.
— and where the user first accesses a biblio-
graphic index and performs an online
search for document references before
placing document orders with the ar-
chive(s) concerned.
Typical system requirements
A recent document
[1]
gives the system specifi-
cation for Apollo, as drawn up by represen-
tatives from the CEC, ESA, Eutelsat, and the
Permanent Nucleus of CSTD/GTD. Some of
the more general requirements are:
— The Apollo transmission system will be a
store-and-forward
satellite transmission sys-
tem specially designed to handle
long
data
messages.
— The size of the information field of a data
message shall not exceed twenty traffic
units:
— The traffic unit is the smallest data block
handled by the system. The binary infor-
mation content of the traffic unit shall be
480kbits. [The binary information content
of a typical compressed digital facsimile
(CCITT Group III) image of a DIN
A4
page
corresponds to about two traffic units.]
— The Apollo transmission system shall
support the following transmission modes.
Point-to-point satellite transmission
Unidirectional transmission of digital
messages from a data station (source)
connected to a transmit earth station, to
another data station (sink) connected to
receive-earth-station facilities.
Point-to-multipoint satellite transmission
Unidirectional transmission of digital
messages from a data station (source)
connected to a transmitting earth station,
to two or more data stations (sinks) con-
nected to receive-earth-station facilities.
— The information rate on the satellite
channel shall be 1920 kbit/s.
— Under normal operating conditions, the
number of simultaneously active earth
stations should not exceed ten.
— The time between
an
acknowledged request
for satellite access from a data station
connected to a transmitting earth station
and the transmission (through the satellite)
of the first bit of the requested information
shall
not exceed five seconds when no station
other than the earth station concerned is
active in the system, and
not exceed fifty seconds when nine
stations are active at the time of the
request.
The Electronic Library, January 1985.
Vol.
3, No. 1. 9
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