Re: POwerline Networking - FYI

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

The AV spec adds a lot of faciliity for QoS. Also one device in the
network
takes the role of co-ordinator and monitors transmissions and can allocate
bandwidth accordingly.

The Connection Manager on an HPAV device is responsible for classifying
traffic prior to sending it on the HP network - it is at this point that
the
standard starts to add scope for variation between implementations by
including the words 'May' and 'Optional'  - as all good standards do!

As this relates to classification within the transmitter different product
will still play together - the receiver does not care it just receives a
stream to be dealt with. Some products will perform better than others
under
particular circumstances based on the sophistication of the particular
implementation. Some products will allow a lot of control over how the QoS
is configured - others will not.


On 3/11/07, Barry Myles <automatedhome@xxxxxxx> wrote:
>
>   David Yeend wrote:
>
> > 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.
>
> HomePlug 1.0 [14 or 85Mbit/sec] doesn't seem to have any quality of
> service mechanisms but HomePlug AV [200Mbit/sec] does, indeed that's
why
> it has the "AV" tag. I've never quite found out how to
explicitly
> activate the mechanisms in HomePlug AV though. According to the specs
> it's capable of 4 types of Quality of Service: Guaranteed bandwidth,
> quasi-error-free service, fixed latency and jitter control. My
> experience is the HomePlug AV is perfect at streaming between my
MythTV
> frontend and backend and I don't think that's just down to the extra
> bandwidth.
>
>


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