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3
STEN RIMBLEUS
Stockholm Telecommunication Area
Swedish Telecommunications Administration
Fig. 2
The brochure distributed by the Swedish Telecommunications
Administration when the AXE
exchange was to be put in service
The Swedish telephone network is to undergo a considerable
renovation The telephone exchanges will therefore
be replaced by new, computer-controlled exchanges
that will permit a large number of new telecommunication
facilities for the subscribers in the future.
The work will start here in Sodertalje on March 1st this
year, when approximately 3000 telephones in the number
series 30 000 - 32 999 will be switched over to a computercontrolled
telephone exchange AH the changeover work
will be carried out at the telephone exchange, and it will
not be necessary to change your telephone set
The new telecommunication facilities will be introduced
gradually and the immediate changes will be that
• the dialling tone comes quicker
D the pitch of the signal is changed
• the ringing signal comes every 6th second instead of
every 10th
• the reference tone is changed to a triad
The next stage of the modernisation program is planned
for the second half of 1978 All telephones in Sddertalie
with numbers that start with 1. 3, 6 or 8 will be connected
to the new telephone exchange in 2-3 years At that time
it will also be possible to obtain all the new telecommunication
facilities.
We will be contacting you again later on and we will then
be explaining what these facilities are and how they
function.
THE TELECOMMUNICATIONS ADMINISTRATION
Sodertalje
— that the operational reliability of the
exchange met the set requirements
— that the traffic with interworking exchanges
functioned satisfactorily
— that the operating instructions provided
took into account all the operating
routines
— that in other respects the exchange
was ready to be taken into service.
Execution
The field trial started with the loading
of the exchange and subscriber data required
for operation. The exchange was
loaded with internal traffic as well as
traffic to and from interworking exchanges.
It was considered as being in
service, and thus all handling was done
in accordance with the applicable operating
and maintenance routines.
The field trial comprised some 30 different
activities, which were carried out
mainly during the daytime. During the
night the exchange was unmanned,
with the remote alarm system connected
to the Stockholm maintenance
centre.
Some of the most interesting trial activities
were:
a. Supervision of test traffic. This comprised
the reading or checking of
— the counter for the subscriber traffic
generator
— call connections
— the results of the weekend tests
described below
— the results of the supervisory tests
that were carried out
— fault printouts (that they were obtained).
It also included keeping a journal of
fault printouts and any measures required
to correct faults.
b. Weekend tests, an unmanned longterm
test that was started on the Friday
evening and finished Monday
morning. Test traffic, traffic recording
and supervision functions were
connected in during this test.
c. Traffic recording for verifying the test
traffic and traffic recording functions
d. Alarm and alarm transmission for
checking local alarm functions and
the transmission of alarms to a superior
centre.
e. Regular charging output for checking
that the charging was correct.
f. Fault diagnosing, repair and repair
checking in connection with the simulation
of
— permanent faults in the synchronously
duplicated central processor
— permanent faults in the current
feeding
— permanent faults in memories
— temporary faults in various devices.
Activity f. comprised checking that the
automatic fault analysis functioned
properly by giving the expected fault
printouts, and also that the operating
instructions were adequate. The faults
that were detected during the various
stages of the field trial were corrected
as they arose.
Result
The faults were recorded in a journal
and divided into categories, such as service
quality, system restart and breakdown.
The Telecommunications Administration
had set requirements for each
category in the form of the maximum
number of permitted faults or maximum
loss of traffic. The test showed that
these requirements were met with a
good margin, and as a result it was decided
to put the AXE 10 exchange into
service on March 1 st, 1977 at 4 a.m.
Putting into service and
subcriber reactions
When the exchange was put into service,
3000 subscriber lines from the
AGF exchange were connected in. The
number series in question included
2430 ordinary subscriptions and also
PABXsubscribersandthree-coin instruments.
Before the exchange was put into service
all subscribers had received a leaflet
from the Administration's Sales Department
with diverse information concerning
the changeover, fig. 2.
The changeover was planned down to
the last detail. Naturally the morning