[e2e] Congestion control as a hot topic in IETF
detlef.bosau at web.de
Fri Mar 8 07:33:18 PST 2013
Am 08.03.2013 15:00, schrieb Jon Crowcroft:
> involve multiple senders competing for a resource,
> and partitioning the use of that resource
> when you have multiple packets in flight (sure, intercontinental fiber a bit, and ong haul radio links more) then
> sure but the origins of the scheme are shared resource in the sense of the output link at the
> the bottleneck as measured by a queue building in the buffer just behind that
> the media type of the link up to that point is irrelevant. the capacity is
As I said above: For VJCC, it simply doesn't matter, /where/ any packet
in flight resides, the packet is in flight and that's it.
> btw, path loss is very real (and not at the antennae)
Or can you tell me where the waves have gone? Where the energy has gone?
Data corruption is a phenomenon which occurs at the receiver. The
problem is that the receiver cannot successfully rebuild a packet from
what he received. The air interface has no idea of which waves are
travelling along and whether they make any sense at all.
> - in freespace, with omnidorectional antennae its
> a feature of inverse square law of spreading the signal over a speherical surface ...plus
> there's atenuuation from signal energy being absorped (e.g. by water vapour or concrete) - etc etc
that are wonderful formulae for the received power. They don't tell you
whether a packet will be successfully read. And that's why I said
formulae, which describe a "bandwidth" depending on the distance
base-station/mobile, I referred to "Modelling Computer Networks for
Emulation" by Rothermel, Herrscher, Leonhardi from 2002, are pleasant to
read, however the model is completely nonsense.
And I wonder, why no communication engineer and no signalling theorist
has made objections here so far, sometimes I think these guys simply
ignore us CS guys because we would continue telling nonsense here and no
one wants to spend his time in useless arguments. I thin, CE and EE guys
simply don't take us seriously.
> your mixing it up with interference with concurrent senders o nthe receive antennae (which is fixable using mimo and
> smart processing - viz
I don't think so. In that paper, one discusses and uses an "effictive
SNR algorithm", is this correct?
And where can you derive a throughput from the SNR? Do you mix up signal
power and data rate? If so, you simply misunderstood the Shannon-Hartley
You may wonder why I get a bit upset here. However, a whole research
project of mine yielded no results and it took years to understand, that
people simply pulled my leg here. I wasted 4 years of my life for this
research completely and years afterwards for indirect consequences.
So, please let's spare discussions on elementary signalling theory.
70565 Stuttgart Tel.: +49 711 5208031
mobile: +49 172 6819937
detlef.bosau at web.de http://www.detlef-bosau.de
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the end2end-interest