[LINK] BPL

[stephen at melbpc.org.au]

Paul writes,

> > i want to know why a lot of Australia has NOT got BB nor probably
> > anytime soon, when it seems that this system apparently works quite
> > well. Is it really only a matter of an incentive?
>   
> Many of the BPL trials never progressed because it couldn't be made 
> cheap enough to compete with the price of ULLS/LSS on a per-user basis
> the technology worked, but was too expensive to compete with DSL.

Yes, i understand. Apparently, one very successful BPL trial was Aurora 
in Tassie, but they write: "Although technically successful, the changed 
commercial environment & the Federal Government Broadband Connect Program 
preclude the investment required for any extension."

Seems a real shame that the Fed Gov BroadBand Connect Scheme killed off
the Aurora BPL efforts. Thus, the scheme that was to provide country BB
actually stopped it in some areas. Eg, in my area the satellite service
which the BB Connect scheme enabled has now also folded. BPL would have
been a much better bet here, so it seems. 

>  From memory, BPL systems suffer from fairly short range (at least the 
> implementations I looked at several years ago), as the power conductors 
> aren't optimised for comms, so signal levels die off within hundreds 
> of metres - maybe a kilometre or two - unless you install boosters ..

Yes .. also read a booster is needed every one klm at around $1,000 each 

> You also need to run the 'head-end' signal all the way out to the last 
> transformer, and inject the aggregate head-end signal onto the wires 

I understand, something akin to termination plugs for yr normal cat5 net

> after the last distribution transformer - and in Australia there are 
> usually a few hundred houses downstream of a distribution transformer,
> 
> That makes BPL look a bit like FTTN (fibre-to-the-transformer) with the 
> last-km infrastructure having shorter range than ADSL, and possessing 
> the shared/contended characteristics of HFC.
> 
> So yes, BPL can work - but it effectively combines the worst 
> characteristics in terms of cost, complexity and performance of most of 
> the alternative platforms, so isn't viable when the alternative 
> platforms are already in place.

So, what about the many Aussies that live, say, 4 klm from an exchange
and can't get an ADSL alternative. Do you know the max BPL distance? Eg
say 5 or 6 boosters might bring many more people into broadband distance. 

> About the only benefit BPL has is that it avoids the capital cost to 
> install a new last-km telecoms-transfer-conduit into each home, which
> is great if there are no other existing telecoms-transfer-conduits 
> available to you, or a competitor for your intended service - such as a 
> telephone  twisted-pair.
> 
> >  
> > If so & word gets around maybe country folk should be majorly pissed
> 
> The main problem for country folks is distance including the lengths of 
> their driveways (and sweaping generalisations). Broadband signals 
> attenuate, whether on metal wires, glass wires or radio waves - and the 
> higher the frequency, the shorter the range. BPL has no solution to fix 
> this.
> 
> (I guess you could QAM-modulate 50Hz mains frequency to distribute a 
> data signal to a long range, but I doubt country folks would appreciate 
> the performance, or what this would do to the appliances that rely on a 
> clean sinusoidal feed). Paul.


Thanks for your expertise, Paul. So, what about up to say 6 klm from the
drop-off point, suggested above. Is this possible with BPL, do you know?
Even a few klm beyond ADSL range might significantly improve matters for
many country folk. (haha, eg me/us) If so instead of the silly satellite
system offered here with BB Connect, which was flakey at best, many here
might still be enjoying BPL broadband, whom can't get ANY bb system now.

So, what happens when a government subsidy kills off apparenly otherwise
quite successful schemes & backs the wrong horse which then goes bellyup
leaving folk worse off than before? So BB Connect v2? I don't think that
will happen given the national BB scheme. Unfortunate all round, really.


Cheers Paul
Stephen Loosley
Victoria Australia