NBN Co has indicated plans to build its long-term satellites with a capability of providing an average download capacity of up to 100 gigabytes to users.
Though the network builder does not sell wholesale products by capacity, satellite project director Matt Dawson said plans for the long-term service would include dimensioning their capacity to support average download quotas of between 60 and 100 GB.
The satellites, to be launched in 2015, would provide a capacity six to ten times that currently available on the 6 Mbps interim satellite service, provided using satellites from IPSTAR and Optus.
Despite service providers offering plans of up to 40 GB on the interim service, NBN Co stipulates in a fair use policy that service providers must not exceed 9.7 GB of data downloads and 3.2 GB of data uploads on average per user, per month.
"We have to deliver a satellite that caters not just to today but over the 15 years of the life of these satellites, it needs to anticipate the sorts of data plans users will need to have," Dawson told iTnews.
"There's no point have data plans of 3 GB or 6 GB - you can use your capacity in the first week."
But, he said, the dimensions were still subject to further tests on the back-end systems.
"We have to make sure we're happy with those dimensions, given the contention, the number of users, the take up and everything else," he said.
"Time will tell how that assumption will turn out."
It is expected that retail satellite plans will retain a premium over similar plans for the fibre and wireless aspects of the NBN, despite the wholesaler charging the same $24 for a 12/1 service across all three technologies. ISPs have blamed the premium on the additional support costs and capacity restrictions on the interim service.
The long-term satellite service will initially offer a peak speed of 12 Mbps downstream and 1 Mbps upstream though Dawson said the company was planning a future roadmap that could see the speeds increased over time.
The two Ka-band satellites would ultimately offer a total capacity of 90 Gbps together, to cover an approximate 200,000 premises not in the fibre or wireless footprints.
"The satellites themselves are not so much the determining factor there, it's more to do with the ground systems which determine those speeds," Dawson said.
Latency no issue
Dawson rejected concerns from some communities that the latency inherent in satellite connections would make it a poor service for medical or other high-bandwidth uses.
He estimated the satellite project would require a latency of about 250 milliseconds, a figure he said was satisfactory for most known applications.
"It's impossible to overcome the laws of physics, latency is a fact of life," he said.
"When you're dealing with satellites that are 36,000 kilometres away in geostationary orbit, it takes a while for radio signals to get there and back again.
"After the first 250ms the latency becomes irrelevant because you're just viewing streamed packets now. It's only those applications that require instant reaction between two parties where it can sometimes become an issue."
Though he conceded instantaneous applications like online gaming could be impacted by satellite latency, other applications including video conferencing and VoIP would not slow down over the service.
Chief executive Mike Quigley has specifically pointed to organisations such as the Royal Flying Doctor Service as potentially utilising video conferencing over the long-term satellite service.
HTTP acceleration and application tests carried out on the interim satellite service had proved that most such applications were already plausible, according to Dawson.
"We've lifted it up a whole order of magnitude really with the interim... with the long-term solution we'll have delivered another notch, the capacity will be ten times that," he said.