[ns] CSThresh_ and RXThresh_

[Daniel Mahrenholz]

On Monday 20 March 2006 08:27, Ashraf Bourawy wrote:
> in addition, in ns-2, the transmission range is set to approximately 250
> m...and the distCST_ is 550 m....
>
> my question is, why is this huge difference? as this will affect the
> performance...and is it required by the standard? I just couldn't find
> anything supporing this issu.....I would appreciate it, if anyone could
> tell me where I can find any explanation about this issue..

It is a common missunderstanding that the transmission / carrier sense 
(interference) range is set to 250 / 550m. They are just the results of the 
choosen propagation model, transmission power, antenna gains, TX/CS 
thresholds.  I have to emphasis it again: you CANNOT set the transmission 
range of a WLAN device (you can only set all named parameters to result in a 
desired range). The default values in ns2 are not very realistic. If you are 
developing new WLAN protocols you should at least use the Shadowing 
propagation model. 

Daniel.
-- 
Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany
Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho