Re: POwerline Networking - FYI

["David Yeend" <david.yeend@xxxxxxxxx>]

Home plug works a little like ADSL where the signal between any 2
devices i=
s
spread across a number of available channels - not all channels are used.

The choice of channels is based on local conditions at the receiver of a
transmission between a pair of devices. So for a pair of devices the
channels used for A to B transmission is different to that for B to A for
the same pair. Local conditions means locally experienced noise. Noise
generated by a device will be dependant on many things and can be highly
variable and unpredictable. Attenuation and 'distance' between the devices
does still have a consideration too.

While LAN technologies like Ethernet have broadcast and multicast modes of
operation Home Plug does not due to the issue of local receiver conditions.
If anyone has tried using Home Plug for synchronised streaming audio on a
system with no buffering or one that is 'busy' you will find it impossible
to get decent synchronisation.

Regards,

David

On 3/5/07, Simon Pawson <SimonP1234@xxxxxxx> wrote:
>
>   Funnily enough I was about to post about my experiences.
> Again Shed as backup site using a NSLU2 with USB HDDs.
> I'm using the AV version of the solwise devices - higher bandwidth.
> "200mbps". Managed 109 TX, 125 RX on the same 13A
distribution board.
> Looking at my numbers running down armoured cable (can't remember size
> now - 20A breaker IIRC) gives about 99tx/113rx at just about the
maximum
> length cable for the allowable voltage drop. (I, sorry they, put in
the
> cable several years ago and it was on the limit at full current)
>
> I hadn't noticed the drop for RCDs but had noticed a drop for surge
> protection distribution boards. Not linear between send and receive.
The
> dozen or so measurements I've done round the house in various rooms
and
> sockets give some quite interesting variations that don't seem to be
> purely cable length. All numbers from the utility supplied - not yet
> calibrated against real world throughput.
>
> I couldn't find a Bargain remote raid solution. Too enterprise a
> requirement.
>
> I'm going to adopt a sort of "lazy-raid" (TM) setup. Some
files will be
> copied once they are a day or so old via ROBOCOP from the NSLU2 in the
> attached Garage (theoretically one hours fire protection from the rest
> of the house). Other things (geovision data) will be copied by leaving
a
> ROBOCOP task running all the time refreshing every minute. That was
why
> I wanted the faster line. Some data will go to a cyclical store so if
I
> overwrite something by chance I don't have two copies of the same,
> broken, data. (Think GDGs for anyone here that understands).
>
> If anyone is interested when I finally get it all set up I'll post
> again.
>
> Simon
>
> In message <02fb01c75f13$079d38b0$6302a8c0@timsnewp4>, Tim
Fletcher
> <timfletcher@xxxxxxx <timfletcher%40breathe.com>> writes
> >HI,
> >
> >just sorted out my XBMC and NAS network problems by using Solwise
> >Powerline networking PL-85E. Bought direct from Solwise @ approx
=A332
> >each inc VAT and delivery - Just plug them in and away they go.
Neat
> >little utility to configure security and measure bandwidth. Looks
like
> >a real 70Mbs on the same ringmain - seems to halve through each
RCD -
> >Garage is half speed, garage through RCD extension is a quarter.
Might
> >not be the case, but that is how it appears. Works fine with all
> >devices - A little more than I wanted to pay, but for less than
=A3100 i=
t
> >seemed easier than pulling and chasing CAT5.
> >
> >No affiliation blah blah.
> >
> >Tim.
> >
> >[Non-text portions of this message have been removed]
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >--
> >No virus found in this incoming message.
> >Checked by AVG Free Edition.
> >Version: 7.5.446 / Virus Database: 268.18.7/711 - Release Date:
05/03/07
> 09:41
> >
>
> --
> Simon Pawson
>=20
>


[Non-text portions of this message have been removed]