[AusNOG] AAB Statement

phil colbourn philcolbourn at gmail.com
Thu Sep 2 23:32:21 EST 2010


In 2007 Optus HFC passed 2.2M homes (including unserviceable and multiple
dwelling units).

Optus wrote-off $1.4B in 2002.

I could assume that to deploy HFC to a home costs $640 for the fibre in the
street, $100 for the NTU and $100-200 for the connection.

Other sources suggest 2.6M homes passed and $6B to build. This averages to
$2000 per home passed plus connection costs.

To pass 93% of 8.5M homes (about 8M homes) it would cost $6.7B to $18.4B in
circa 2000 dollars.
So the cost today would be, say $10B to $30B.

Both Optus and Telstra gave up after the rules changed and it was not as
easy to roll-out cable. Soon after they both wrote-off large amounts of the
value of the HFC assets, presumably because they could not make a return on
the investment.

I suspect that the NBN proposal will be more costly because after the first
few million houses, the house density drops and the cost per house
increases. This is why they will not be doing the last 7%.

Now to have any reasonable broadband network we need backhaul fibre. So step
one should be a national fibre backbone network. We probably have most of
this in place.

Step two, we 'need' to get 100 Mbps to 93% of homes. So the lowest cost
solution, if we are looking at fibre, is a FTTN/C architecture where a node
is 100 to 300m from each home. At about 100m I suspect this could get to
Gbps speeds in due course.

Then, as the need arises, the last section of copper can be replaced with
fibre.

But what if we could get Gbps to all base stations?

LTE and LTE-advanced offer 'up-to' 1 Gbps per sector or more given enough
spectrum. A 6 sector base could provide 6Gbps or about 3Mbps per sub on
average (assuming 2000 subs per BTS). Real traffic volumes are much less
than this: From memory, ABS reported total downloaded data of about 120,000
TB/year. This is about 30 Gbps on average. Assuming all of this is
downloaded in 6 hours, this increases to about 120 Gbps. Say we have 10,000
base stations, each BTS only needs a 12 Mbps link on average. Telstra
have/are rolling out 100 Mbps links to their base stations.

For 1 Gbps peak, a minimum aggregate of about 20 + 20 + 20 MHz (60 MHz) is
required. This can only be aggregated when R10 is standardized I think.

Note that at the moment there is no proposed device that can do more than
300 Mbps, so this is the current limit.

For at least 2 carriers there is 20 MHz available in the Digital Dividend in
2013.
For 3 carriers, there is (roughly) 20 MHz in 1800 and 20 MHz in 2100.

But, the digital dividend spectrum is for coverage, not high data throughput
so an additional 20MHz is required. This is likely to come from the 2.5G
band in 2013. At least 2 carriers will get 20 MHz each.

I also suspect that the 850 and 900 band will be re-structured in the future
to make another 30 something MHz available for each carrier on average.

If distributed fairly, there is enough spectrum for at least three 1 Gbps
wireless networks.

Further increases in capacity will probably have to come at the cost of
increasing the number of base stations - probably micro cells and home
pico/femto cells.

I think wireless is an attractive option. The NBN has to rely on wireless
for at least 4% and 3% will get satellite. I think it is more likely that
LTE will play a much bigger role in the NBN rollout, especially in regional
areas. The sites already exist in the most optimum locations for digital
dividend base stations. They already have some high capacity backhaul
infrastructure in place and this should be low cost to upgrade as demand
increases.

In the business/retail locations there is probably an exchange where higher
frequency 1800/2100/2500 systems can provide the high capacity.




-- 
Phil

http://philatwarrimoo.blogspot.com
http://code.google.com/p/snmp2xml

"Someone has solved it and uploaded it for free."

"If I have nothing to hide, you have no reason to look."

"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke - Who does magic today?
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