1975 ONWARDS (continued)

10C medium local system offered by STC,
AXE system offered by LME Pty Ltd.

The STC offer was for an established system, working in a network of exchanges which although developed in the late 1960s had undergone several stages of evolution, with a further significant evolution current in association with the adaptation of the system to incorporate the new ITT 1602 processor. The AXE was a more modern, although not fully developed, system based on advanced concepts which had evolved during recent years and which allowed greater exploitation of the stored programme technique than was economically possible with earlier systems. The flexible modular structure of AXE, covering hardware, software and mechanical design, was seen as providing many advantages in the various areas of Telecom involved in system management. Design work on AXE was pressed ahead by LME during the evaluation period and by early 1977 a working field exchange had been established in Sweden and orders were being negotiated by LME with several countries. Telecom's final assessment that AXE was a superior design which could be utilised more effectively and economically in the Australian network than could the 10C medium system, came after extensive analysis by a team expert in a range of fields, discussions in Australia at the most senior level between Telecom and the representatives of STC and BTM Antwerp, as well as with LME Australia and Sweden and followed by a visit of specialists to the overseas design houses.[57]

The decision to purchase AXE was based on the offer of an analogue system but in the knowledge that a Digital Group Stage (DGS), work on which had begun by LME in Australia in 1974 as part of the overall AXE design programme, would be available at an early date. Further studies, concentrating on tandem switching strategies, resulted in a decision to adopt the digital version and only one exchange using an analogue group selector stage was installed. One substantial advantage of the digital AXE was seen as the availability of four wire switching at the tandem and local level, as well as at the trunk exchange, foreshadowing the development of non-hierarchical switching and routing. Thus the interest in digital switching and transmission which had begun in the APO Research Laboratories in the early nineteen sixties and to which H. S. Wragge was to contribute in an ongoing way, began to appear as hardware in the network almost twenty years later and shortly before Wragge was to become Director of the Laboratories.

The contractual arrangements for the supply of AXE equipment included direct importation of the first year's bulk order, but local content was then to progressively increase, achieving approximately 80 per cent by year four. The contract included provision for licencing of a second manufacturer when orders reached a pre-determined level and in due course STC became the second supplier of AXE equipment.

As with earlier introduction of new switching systems, substantial work was involved in designing elements of the system to meet Australia's particular requirements, in transferring the technology to Australia, and in interfacing the new technology to the existing network, while, in order to obtain the advantages inherent in digital switching, extensive re-design of various features of the network was also necessary. One significant network change was the use of remote digital subscribers stages (RSS-D) as a means of spreading AXE thinly over a large number of exchange locations, thus quickly providing digital facilities to major users as a part of the development of an Integrated Digital Network (IDN). But before giving some brief details of the IDN, it is necessary to refer to developments which had been taking place elsewhere in the network.

Australian Academy of Technological Sciences and Engineering