ITWire

An NBN Co spokesperson said: "There are a number of complex factors which go into the rollout sequence of the NBN, particularly in the early years where much of our focus is in establishing the transit network - the backbone of the NBN. Without it, there is no connection between any premise, libraries included, and our Points of Interconnect where traffic gets handed off to the retail service providers who are the ultimate service providers to end-users, including local government and libraries.

"At the moment, the constraints around delivering the transit network are very much a dominant consideration in our rollout. Once the transit network is established, NBN Co gains more flexibility to take account of other criteria. It is our intention to try to take into account critical local public infrastructure - schools, hospitals, libraries, etc - once we gain this flexibility."

The spokesperson added: "Until then, we are doing what we can to connect public infrastructure wherever possible to existing footprint. For example, we are working with the Townsville City Council to connect their Aitkenvale Library, which is across the road from the existing Release 1 footprint there. This library is in turn connected by fibre to a number of other libraries across the city."

According to NBN Co the Transit Backhaul network will comprise some 57,000kms of fibre, much of it leased from existing owners of fibre networks. "It is required predominantly in rural and remote regions to enable aggregation of communication traffic to a scale required to provide effective and efficient points of interconnect (PoIs) for NBN Co's wholesale access seekers. This network will be a common network used for all three network technologies (fibre, wireless and satellite) and NBN Co's own needs for managing the network," the corporate plan states.

In major centres PoIs will be collocated with fibre access nodes. However NBN Co will still need backhaul from these PoIs to carry its network management and signalling traffic.

The corporate plan adds: "In determining the requirement for transit backhaul, NBN Co has considered the routes currently being constructed as part of the Government's Regional Backhaul Blackspots Program. Where these routes overlap with NBN Co's transit backhaul requirements, the costs of NBN Co acquiring the routes in the future have been factored in to NBN Co's capital expenditure forecasts." The corporate plan envisages construction of the network being completed over four years.