Alternative view - a third is needed to be planned at least, to provide N+1
redundancy, because of the very long replacement time if one of the existing
satellites is knocked out by debris, meteoroid, accident or malfunction.

We've seen what happens in the current Basslink cable situation. For a decade 
the
Basslink electricity cable has been criticised by Tasmanians as an unnecessary 
and
expensive parasite on the Tasmanian budget.  Now that it has unexpectedly 
failed for a
few months, it has suddenly become critical infrastructure with calls for 
several
state and commonwealth inquiries, heads to roll, and a second cable to be built 
to
ensure non-stop supply from the mainland so that Tasmania never again has to 
choose
between drinking the water or keeping the lights on.

Thats what happens when you rely on one of something.

Same calls at the moment for the optical fibre cable component, with calls for
'someone' to build another fibre cable into Tasmania, even though Tasmania 
still has 2
out of 3 optical fibre cables operating.

The initial NBN satellite was planned as a pair, operating as active-active with
roughly 50% load on both, to provide this redundancy if one should fail in 
orbit (or
be lost at launch), with latent capacity to cater for a decade of future 
growth. The
experience of the interim service demand profile indicates both satellites will
running above 50% capacity soon after the second is launched - which means if 
one of
the satellites fails in orbit, the satellite NBN service will instantly become 
as
congested and unusable as the current interim service is - and would remain 
like that
for years if the replacement satellite wasn't even on the planning table at the 
time.

Paul.



On 25/03/2016 8:40 AM, David Boxall wrote:
> A third? The first isn't fully operational and the second hasn't even 
> launched!
> Didn't Turnbull say that the satellites are unnecessary extravagances?
>
> <http://www.businessspectator.com.au/article/2016/3/21/technology/does-nbn-need-third-satellite>
>
> "Australia’s efforts to become a leader in the global digital economy will 
> soon take
> another giant stride ..." Sounds like propaganda.
>
> "The NBN is a visionary nation building infrastructure project ..." Come now! 
> It's
> an effort to repair some of the harm done by alienating essential 
> natural-monopoly
> infrastructure from public ownership.
>
> "... there is growing demand from business and industry for improved 
> broadband in
> regional and remote Australia." At what point does it become more 
> cost-effective to
> build optical fibre infrastructure, with its century or so service life, than 
> to
> repeatedly replace multi-billion-dollar satellites, with their one to two 
> decade
> service life?
>
> "Australia has been lagging behind other nations when it comes to building
> infrastructure and providing future-proof broadband, especially in regional 
> and
> remote areas." Was that true before the infrastructure was privatised? Are
> satellites future-proof?
>

_______________________________________________
Link mailing list
[email protected]
http://mailman.anu.edu.au/mailman/listinfo/link

Reply via email to