Chapter 8
I Part 1: Communications
i Before the Telegraph
ii Electrical Communication Before Federation
iii Federation to the End of the Second World War
iv Post-war and on to 1975
v 1975 ONWARDS
II Epilogue
III Part 2: Early Australian Computers And Computing
IV Acknowledgements
References
Index
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Post-war and on to 1975 (continued)
The first bulk supplies of ARF minor centre equipment with REG-ELP/H4 and full STD facilities were delivered in 1969/70, by which time a large number of minor centres had been equipped with REG-LM. The new equipment was used mainly at new minor centres but, as resources permitted, was also used to upgrade older centres, with first priority given to step by step minor centres which were fitted with SR-B and crossbar first stages, and replacement of REG-LM registers given a lower priority. By this time a uniform approach to minor centre design had been established, including six digit numbering as standard and with several minor areas in a single numbering area. Most minor centres were in towns with 1000 or more subscribers and used ARF for local and minor area switching, while terminal exchanges were generally small and a mixture of magneto, APO RAXs, ARK-D and ARK-M exchanges. The APO RAXs could not be given closed numbering and retained the old arrangement of two or three digit local numbers with all other numbers prefixed by '0'.The relatively large country cities, with populations of the order of 100,000 and supported either by industry or tourism, of which Geelong, Wollongong and the Gold Coast were examples, had networks which included several large exchanges. These required designs which were similar to the capital cities but on a smaller scale and usually embedded in a minor area which was partly rural. The minor centres in these networks had to be individually designed to perform as a tandem centre for the built-up area as well as a minor centre for the periphery. Conversion of country terminal exchanges to automatic using ARK was pursued fairly vigorously as soon as the equipment became available, generally using portable buildings and standard exchange designs for sizes up to 1400 lines.
When the ANSO Committee's proposal for extended local service areas was introduced, there was quite a dramatic impact on the number of trunk calls to be switched by the various trunk exchanges, illustrated by the Australia-wide reduction of trunk calls from 134 million in 1959/60 to 75 million in the following year. This reduction, together with development of point to point STD using locally designed equipment, provided time for the development of ARM and ARF minor centre designs. As an indication of the extent of point to point STD, by 1967, the year in which the first ARMs became available, some 19 per cent of all trunk calls were being directly dialled by subscribers. The ARMs, however, introduced a new phase as initially some 250,000 subscribers obtained access to a wide range of destinations and the ARM network was extended rapidly to include all capital cities as well as eighteen country centres two years later.
As studies progressed over the period between 1960 and 1967, influenced not only by the crossbar design considerations detailed earlier, but also by the reducing costs of transmission relative to those of switching, a new trunk switching plan was evolved. Table 5 illustrates the extent of the change, not only over that period but extending into the ensuing decade as well.
Organisations in Australian Science at Work - Automatic Network and Switching Objectives (A.N.S.O.) Committee
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Australian Academy of Technological Sciences and Engineering |  |
© 1988 Print Edition pages 581 - 582, Online Edition 2000
Published by Australian Science and Technology Heritage Centre, using the Web Academic Resource Publisher
http://www.austehc.unimelb.edu.au/tia/562.html