[e2e] VJCC vs. Keshav

Detlef Bosau detlef.bosau at web.de
Thu Apr 18 15:38:04 PDT 2013

Am 19.04.2013 00:22, schrieb dpreed at reed.com:
> 7 WiFi LANs tend to interact in interesting ways. I do believe you can 
> probably model the physics if you have the complete physical model of 
> the environment, including the motion of people, objects, etc. and 
> also a model of the specific antenna locations and positions, as well 
> as precise timings and indices of refraction.

O.k., that's difficult.

> But this is not the real problem.  The real problem is that the 
> programs and humans that generate the traffic generate that traffic 
> dependent on the communications performance they observe.

Don't blame my neighbours ;-)

However, I agree. That's the real problem. I cannot simulate my 
neighbours, neither their behaviour.

> That is, I don't usually click on a link until I've received the page 
> and had it displayed, but not always - sometimes I interrupt the 
> process and go on to the next link.  Similarly, the low level MAC 
> protocol involves several components of behavior.  If, for example, 
> noise is detected at a certain level (way below the signalling levels) 
> in the 4 microseconds before a transceiver is about to send a packet, 
> the packet will not be sent.  But during this interval other stations 
> will hear *different* noise, because noise is not equi-potential 
> simultaneously across the stations on the 7 WLANs.   So small 
> variation during intervals as short as 4 microseconds can have 
> amplified effects.

In this context, I remember a recent discussion in the German part of 
the usenet: There are apparently different strategies how WLAN AP choose 
their channel, particularly when adapting to a certain channel load 
situation. From that, I conclude, we would have to simulate not only 
different brands and different software releases.

Detlef Bosau
Galileistraße 30
70565 Stuttgart                            Tel.:   +49 711 5208031
                                            mobile: +49 172 6819937
                                            skype:     detlef.bosau
                                            ICQ:          566129673
detlef.bosau at web.de                     http://www.detlef-bosau.de

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.postel.org/pipermail/end2end-interest/attachments/20130419/3be3760f/attachment.html

More information about the end2end-interest mailing list