Re: How to make the fading nodes in the wireless network?

[AL-HUSSEIN ABOU-ZEID <hussein@maxwell.ee.washington.edu>]

> 
> On Wed, 01 Sep 1999 12:28:05 +0900, "Kang, Yoonsik" wrote: 
> >Hi.
> >I have some question.
> >I wonder how to make fading node in wireless network-the node that can't reach the access-point during some period.
> >After the period, it must be able to reach access-point.
> >please, tell me how to make this.
> >Thanks for your help.
> 
> What are you trying to simulate?
> If it's fading due to distance, move the node.
> If it's unreachablility due to cross traffic, simulate cross traffic.
> ...
> 
>    -John Heidemann
> 

I guess our friend here refers to multi-path fading, and not the
loss of signal due to the increase of the distance. My answer to him is to
use some model that introduces random fades in the channel, depending, for
example, on the average fade durations. A crude model maybe a 2 state
error model. If you like, you could use my modified err* files.
Download it from
http://students.washington.edu/~abouzeid/nsfiles.htm

And by the way, John, it may be a good idea to add these modifications to
the CMU extension, or to ns in general, so as to be able to model
multi-path fading, in addition to other sources of impairment in the
wireless medium, like shadowing and distance-caused loss of signal. Refer
to my earlier e-mail  
http://www-mash.cs.berkeley.edu/dist/archive/ns-users/9908/0369.html
regarding this.

Regards,

Hussein.