1975 ONWARDS (continued)

As the SEACOM cable neared the end of its design life, OTC on behalf of Australia negotiated an international agreement for the provision of a telephone cable, technically similar to ANZCAN, from Perth to Jakarta and Singapore -the AIS cable, and a contract was signed on 20 July 1984 with STC. In Singapore, the AIS cable will connect to new cables being provided from there to Hong Kong and to France via Sri Lanka.

International telephone switching capacity was expanded by the commissioning in 1982 of an L. M. Ericsson AKE-132 processor controlled gateway exchange at Pad-dington, generally similar to the AKE-131 at Broadway, but incorporating a number of new features resulting from advances in switching technology. A new international Transmission Maintenance Centre was also provided.

One of the important developments concerning the capabilities of computers and communications is the ability to remotely access, over communication channels, information stored in computers. Growing interest by Australians in accessing data bases in the USA, particularly at libraries, was reflected in traffic over the ISD system, a relatively expensive method for the customers. In 1979, therefore, MIDAS (Multimode Interactive Data Acquisition Service) was introduced, involving proprietary equipment and a part of the TYMNET network. A packet switching techniques was employed to multiplex low speed data terminals (300 bps) on to an error-protected high speed (2.4-48 kbps) bearer. Call establishment, clearing, billing and network supervision, were all performed from USA. Within a few years it was necessary to expand the packet facilities to provide additional capabilities. To this end a Siemens EDX-P data gateway was brought into service in 1984. This gateway performed the packet assembly/disassembly functions and packet switching functions of the earlier equipment. In addition it was connected by a 48 kbps link to Telecom's AUSTPAC network. High speed links also connect the data gateway to a number of overseas locations.[68]

A major development in network management came in 1978, when an order was placed on L. M. Ericsson for a computer controlled network monitoring centre to supervise the performance of their two gateway exchanges and by 1982, complete details of the performance of both exchanges and of all destinations and routes were available. Arising from this a series of network management strategies to cover all peak days throughout the year and all practicable failure conditions was developed. Australia's leading role in this area has been recognised by world-wide acceptance of its procedures in the installation of similar centres by other administrations.[69]

Although increased security through diversity has been an ongoing objective, as instanced by the network of cable and satellite routes, Australia's two gateway exchanges located in Sydney, at Paddington and Broadway, while having operational advantages caused, from a security viewpoint, an undesirable concentration of facilities. Studies which were undertaken to develop a strategy for greater diversification without significant cost penalties, resulted in a decision to establish a third international gateway at Scoresby, in the eastern suburbs of Melbourne, with a satellite earth station further to the east at Healesville, in a valley where it would be largely free from technical interference. The Scoresby site is close to the Melbourne digital network being developed by Telecom.

Australian Academy of Technological Sciences and Engineering