geostationary telecommunications satellites electronic telephone set ...

LM Ericsson Technics
In connection with a presentation of
LM Ericsson technics the new Technical
Director, Bjorn Svedberg, delivered an
address. During the course of the address
a demonstration was given of the AXE
exchange which is being installed in Sodertalje,
a town a few miles south-west of
Stockholm. Large TV monitors were used
for the demonstration and the pictures
were transmitted direct on a link from
Sodertalje.
Bjorn Svedberg said, among other
things:
— 'Through the technical developments
that are going on around us all the time,
we are getting more and more advanced
telecommunication services and products.
But what then does "more advanced"
mean for the people affected, and how
does this affect the products
Subscribers who ring from Stockholm
to Sydney observe that it sounds well
despite the distance, but hardly give the
technical problems a thought. If the subscribers
only realized the enormously
comprehensive systems and the untold
number of components that were activated
when a long-distance call was made, they
would most likely never dare to make
one. But everybody is concerned about
how it "sounds". A good sound quality,
such that the voice can be identified and
the speech understood, is therefore one
of the most important fields in technical
development.'
As an example the new ERICOFON
700 was demonstrated. This telephone
set has an electret microphone in which
an easily-moved thin plastic diaphragm,
which is charged electrically, is affected
by sound waves from speech, and in
which the micro-electronics in the speech
circuit give a very high technical transmission
quality of the speech.
Increased knowledge of components
— 'New digital transmission systems,
which for telecommunications administrations
mean reduced costs for copper
lines in the local network, since parts of
the exchange equipment (remotely controlled
concentrators) can in future be
moved nearer the subscriber, are now
being designed. The whole of this technique,
with its specialised and highly integrated
semiconductor techniques, will
result in greater demands on the designer's
knowledge of the technical possibilities
and limitations of the components.
This means that collaboration between
the system and component designers
will increase. Good contacts and resources
for the development and production
of semiconductors is necessary for a
telecommunications enterprise.'
Classic mistake
— 'We put our first computer-controlled
(SPC) telephone exchange in operation
in Tumba, a suburb of Stockholm,
in 1968, and it is still giving excellent
service. However, this local exchange
system was too large and too complicated
for export on a large scale.
That now almost classic mistake that
we and all other companies made, who at
that time took up the development of
SPC systems, was to underestimate the
difficulties of producing computers and
software for the control of telephone exchanges.
The reliability and size requirements
were so severe that the usual computer
manufacturers were unable to help
us on this occasion.
Since then thousands of man-years
have been devoted to the development of
SPC systems and great progress has been
made. In our new systems (for example
AXE) the control and checking functions
are divided up between a large central
processor and a number of small regional
computers with special programs, which
has been possible thanks to modern circuit
techniques.
The reason that the exchanges have
such a structure is that the computer capacity
can then be obtained in the form
of building blocks in a modular system.
By this means the system can be adapted
in the best way for use in different types
or sizes of exchanges. The modular structure
is also necessary in order to be able
to introduce new techniques successively.'
Svedberg also pointed out how important
it was to design the computer-controlled
exchange systems so that the staff
responsible for the day-to-day operation
and maintenance were able to understand
the best way of handling such systems.
Man—machine
— 'A good man—machine relationship
is extremely important if it is to be possible
to get the most out of the systems.
The computer-controlled exchanges are
extremely complicated but they are designed
so that outwards they are simple
and thus easy to handle. A well designed
high-level program language helps to
make it possible to understand what
happens in the system. Experience of the
program language PLEX. developed by
ELLEMTEL. has hitherto been good in
the Sodertalje exchange.'
Bjorn Svedberg, new Technical Director after
Christian Jacobceus who retired on June
30th
Nordic data network
to be equipped by
LM Ericsson
The telecommunications administrations
of Denmark, Finland, Norway and
Sweden have made out a letter of intent
to LM Ericsson which applies for the first
phase of an internordic public data network.
The contract is to be signed before
November 30th this year.
The first phase includes equipment to
a value of about 200 MSKr, which is to
be put into operation at the end of 1978.
In this stage the network will cover the
four Nordic capitals and will serve about
11,400 subscribers.
The equipment comprises data exchanges,
concentrators and multiplexors
and will be manufactured in all the four
countries. The network is based on the
LM Ericsson SPC system AXE, which
has recently been chosen by the French
Telecommunications Administration for
future extensions to the telephone network
in that country.
The background to the Nordic public
data network is that in 1971 the Swedish
Telecommunications Administration put
forward an investigation report concerning
a nationally standardized public data
network as an alternative to the different
types of data networks for private use.
arranged with the aid of leased point-topoint
telecommunication circuits, which
hitherto have handled the rapidly expanding
traffic. All the European countries
had similar ideas. The four Nordic
countries decided to build up a common
network and last year tenders were invited.
The project is one of the largest
civil data ventures in the world.
France
chooses AXE
On Thursday May 13th this year the
French President in Council decided to
order the newly developed telephone exchange
system AXE from LM Ericsson
for future extensions to the French telecommunications
network. In addtion to
AXE the Metaconta system from ITT
and E 10 from CIT are also to be installed.
The decisition is the result of invitations
to tender that were set out in May
1975 and concerned SPC telephone exchanges
with analog switching networks.
Other enterprises that submitted tenders,
in addition to LM Ericsson and ITT,
were NEC with D 10, Northern Telecom
with SP-1, Philips with PRX 205 and
Siemens with EWS. After very careful
studies SP-1, PRX 205 and EWS were eliminated
in the first stage and D 10 in the
final stage.
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