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<div class="moz-cite-prefix">Am 08.03.2013 15:00, schrieb Jon
Crowcroft:<br>
</div>
<blockquote cite="mid:E1UDxqT-0002JL-QL@mta0.cl.cam.ac.uk"
type="cite">
<pre wrap="">congestion/contention
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</pre>
</blockquote>
<br>
As I said above: For VJCC, it simply doesn't matter, <i>where</i>
any packet in flight resides, the packet is in flight and that's it.<br>
<br>
<br>
<blockquote cite="mid:E1UDxqT-0002JL-QL@mta0.cl.cam.ac.uk"
type="cite">
<pre wrap="">
btw, path loss is very real (and not at the antennae) </pre>
</blockquote>
<br>
no.<br>
<br>
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.<br>
<br>
<blockquote cite="mid:E1UDxqT-0002JL-QL@mta0.cl.cam.ac.uk"
type="cite">
<pre wrap="">- 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</pre>
</blockquote>
<br>
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.<br>
<br>
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.<br>
<br>
<blockquote cite="mid:E1UDxqT-0002JL-QL@mta0.cl.cam.ac.uk"
type="cite">
<pre wrap="">
your mixing it up with interference with concurrent senders o nthe receive antennae (which is fixable using mimo and
smart processing - viz
<a class="moz-txt-link-freetext" href="http://conferences.sigcomm.org/sigcomm/2012/paper/sigcomm/p235.pdf">http://conferences.sigcomm.org/sigcomm/2012/paper/sigcomm/p235.pdf</a></pre>
</blockquote>
<br>
I don't think so. In that paper, one discusses and uses an
"effictive SNR algorithm", is this correct?<br>
<br>
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 Law.<br>
<br>
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.<br>
<br>
So, please let's spare discussions on elementary signalling theory.<br>
<br>
<br>
<pre class="moz-signature" cols="72">--
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