No subject

tus cable network past 3 million homes</div><div style>=A0 Telstra spent $4=
B (199x dollars) to build Telstra cable network past 4 million homes</div>
<div style>
Since they both targeted the same customer market, that means roughly</div>=
<div style>=A0 $2,000 was spent on infrastructure to each of 3 million home=
s</div><div style>=A0 $1,000 was spent on infrastructure to each of 1 milli=
on homes</div>

<div style>That was 15 years ago, so dollars were probably worth 3 times wh=
at they are now.</div><div style><br></div><div style>Why did Optus and Tel=
stra do that?</div><div style>Mostly because they though they could make mo=
ney, and to stop the other guys from getting money.</div>

<div style>Commercial business processes would have required a payback in s=
ay 7 years.</div><div style>[ Why did they _both_ have build their own netw=
ork? Because there wasn&#39;t a wholesaler / retailer split, like what the =
NBN is building now. ]</div>

<div style><br></div><div style>Put another way, how much do people spend o=
n fixed line communications?</div><div style>A $30 per month phone line ren=
tal (voice, or ADSL) is $360 per year, or $7,200 over 20 years.</div><div s=
tyle>

Tap some portion of that rental fee, and you can pay off a large infrastruc=
ture build cost.</div><div>=A0</div><blockquote class=3D"gmail_quote" style=
=3D"margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(20=
4,204,204);border-left-style:solid;padding-left:1ex">


I understood that data transmission via electricity supply lines, is<br>
faster and less expensive, as the network of lines already exists. I<br>
believe that data transmission via electricity supply lines, has been<br>
used successfully in Europe, for some years, now (of course, we are way<br>
behind the rest of the world - that is the policy of the federal<br>
parliament).<br>
<br>
Of course, I could be wrong...</blockquote><div><br></div><div style>Yes, y=
ou could be ;-)</div><div style><br></div><div style><a href=3D"http://en.w=
ikipedia.org/wiki/Power_line_communication">http://en.wikipedia.org/wiki/Po=
wer_line_communication</a><br>

</div><div style><a href=3D"http://en.wikipedia.org/wiki/Broadband_over_pow=
er_lines">http://en.wikipedia.org/wiki/Broadband_over_power_lines</a><br></=
div><div style><br></div><div style>There are certain rules-of-thumb in dat=
a communications, simplified as</div>

<div style>- the data transmission speed is inversely related to the distan=
ce covered</div><div style>- you can only have one signal in same (location=
, medium, frequency)</div><div style><br></div><div style>So, you can do hi=
gh-speed data over power lines</div>

<div style>if you limit yourself to in-home (and you rely on external losse=
s to stop interference between homes),</div><div style>or to the home if ev=
ery home uses a different carrier=A0frequency,</div><div style>or if you us=
e separate wires from the suburb transformer / data hub to each house.</div=
>

<div style><br></div><div style>FTTH has advantages in</div><div style>- na=
tive fibre data rates are very high (2.4 Gbit/s)</div><div style>- data rat=
e drop-off with distance is much lower than for copper</div><div style>

- a fibre supports multiple frequencies (16 CWDM or 100+ DWDM)</div><div st=
yle>- fibre are thin, cheap, light, low cross-talk, corrosion-resistent and=
 require little power - which makes it easy to get physical separation by r=
unning a separate fibre to each house.</div>

<div style><br></div><div style>See=A0<a href=3D"http://en.wikipedia.org/wi=
ki/GPON">http://en.wikipedia.org/wiki/GPON</a></div><div style><br></div><d=
iv style>=A0 =A0 John</div></div></div></div>

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