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Technology in Australia 1788-1988Australian Academy of Technological Sciences and Engineering
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Table of Contents

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)

Although by the end of the first post-war decade many of the immediate problems of meeting the greatly increased demand for telecommunications services within Australia had been successfully overcome, a number of quite fundamental problems, involving technical, financial and service issues, and relating to such diverse matters as numbering, local and trunk switching, broadband systems, the extension of local service areas, direct dialling of trunk calls and methods of charging, needed to be drawn together. To this end in 1957, the APO established a special planning group, the Automatic Network and Switching Objectives (ANSO) Committee, led by R. W. Turnbull, utilising expertise and experience from Head Office and the States. After three years of work ANSO produced the Community Telephone Plan for Australia I960,[34] perhaps the most comprehensive plan produced, to that time, by any telephone administration.

From a technology viewpoint, important features included:

  • ultimate nation-wide subscriber dialling;

  • national closed numbering with a maximum of nine digits;

  • grouping of exchanges for call charging;

  • extended local service areas;

  • automatic multi-metering on trunk calls;

  • register controlled, high speed switching system, using automatic alternative routing; maximum of nine links in tandem.

As many of the world's manufacturers of switching equipment were then developing new equipment lines, it was opportune for the APO to choose a new system and have it adapted to its needs. Accordingly a schedule was issued inviting offers and after extensive investigations by a team reporting to F. P. O'Grady, the L. M. Ericsson crossbar system was selected. LME's offer for crossbar included ARF terminal exchanges, ARM 50 series small trunk exchanges, ARM 20 series large trunk exchanges, ARK (M) small terminal exchanges and, apparently added to meet APO particular needs, ARF tandems and ARK minor centres. The switchblocks of all these exchange types had been in use for some time, mainly with DC signalling techniques and in register controlled networks but, although LME was moving to MFC signalling, the details had not yet been finalised. The APO and LME, initially using Swedish resources but later developing considerable expertise in Australia also, collaborated in developing the MFC versions of crossbar and the result was a system which was well matched to Australian needs, with the flexibility to satisfy the requirements of other countries. In the process the system changed extensively.

In order to gain some early experience with crossbar equipment, a contract was let to install an ARF 101 exchange with DC signalling at Toowoomba, Queensland, where interworking problems would be limited.{35{ It was brought into service in 1960, three years before the first ARF 102 exchange with MFC signalling was cutover in May, 1963. The new ARF system was coded ARF102 and although it was developed from the ARF101 type, it was in many respects a new system. The major changes were:

  • Provision of an extra wire (UHE 'C' wire) through the group selectors to provide a signal path between FIR and FUR and allow the relay sets to be set to suit the type of connection

  • Eliminating the B party ring delay set LKR by adding this facility to FIR and SR relay sets

  • Providing much more analysis capability and removing the analysis from the Reg-L to the IGV stage

  • Adding a 'waiting place' function to the IGV as a means of reducing post dialling delays

  • Adding a decadic sending function to the Reg-L and Reg-I instead of providing a signal conservation register (Reg-U) at the interface with step by step

  • Producing a different IGV stage with greater flexibility in availability allocation and more extensive alternative routing facilities

  • Increasing the number of backward frequencies from three to five, allowing 10 different signals

  • Designing MFC signalling code to allow the extra signals needed with analysis in the GV stage and decadic signalling from the registers Two new SL stage configurations were provided for very high calling rate subscribers and a faster SLK stage marker was developed


Organisations in Australian Science at Work - Australian Post Office (A.P.O.); Automatic Network and Switching Objectives (A.N.S.O.) Committee; L. M. Ericsson

People in Bright Sparcs - O'Grady, F. P.; Turnbull, R. W.

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© 1988 Print Edition page 572, Online Edition 2000
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