Australia has very highly developed domestic communications networks, particularly in and between the major cities along the eastern seaboard. In addition, a number of established and new entrants are expanding the coverage and capacity of the domestic `backbone' network.
Optic fibre is the predominant technology used within Australia, supporting over 95 per cent of the `backbone' network. Satellite and microwave networks are used mostly to service regional and rural areas. They also serve as a backup facility for the fibre optic networks in the population centres. A comprehensive list of the domestic networks is provided in Appendix B.
Australia's key eastern seaboard capitals of Sydney, Melbourne and Brisbane are currently linked by three major fibre optic `backbone' networks. There are also two established networks linking the southern seaboard capitals of Perth, Adelaide and Melbourne. This configuration provides large business users with significant bandwidth capacity, route diversity and the ability to access high growth and new generation services such as data, video, Internet, intranets and meet private corporate network bandwidth requirements. Service providers maintain bandwidth redundancies that further ensure reliability and quality of service.
The volume of installed capacity in the domestic networks is estimated to be many times current usage. In fact, one survey reported that only one per cent of existing inter-city capacity was used in 1999. In addition, recent estimates of capacity suggest that potential capacity (brought online through fibre upgrades and the application of Dense Wave Digital Multiplexing (DWDM) technology) in existing infrastructure is many times that of the installed capacity. All major providers of `backbone' capacity are currently implementing DWDM.
It is difficult to obtain firm data on domestic bandwidth as much of the information is commercially sensitive and dates quickly.