Re: VJCC vs. Keshav
Detlef Bosau <[email protected]>
| Newsgroups | gmane.network.end2end |
|---|---|
| Message-ID | <[email protected]> |
Am 19.04.2013 00:22, schrieb [email protected]: > > 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 [email protected] http://www.detlef-bosau.de