RE: [ns] Error Model in Wireless Network

["jahn-isi" <jahn@ISI.EDU>]

The following is what I think about your questions.

>I think the variable error rate problem can be partly solved by using multi-state error model,
>although it does not do all what we need, for example it's impossible if I would like to simulate the
>error rate increasing gradually from 1% to 10% (packets) during a period from  0 to 10 seconds.

Somehow, by the multi-state model, we can model the gradual error increase even though the
transitions would be periodical ultimately. Like, we can create 10-state error model with time transition unit and
we can specify each transition time from a state to another.  I am not sure why you think that the gradual 
error increase is impossible.

>The second problem, (the changes of physical bandwidth) does not seem to have an answer yet. I mean,
>can we set a link to have "multi-state" bandwidth or can we change the channel bandwidth "on the
>flight".

I am not sure about this. I guess that the dyanmic change of the physical bandwidth is impossible
in ns now since most configuration parameters are statically set at the start time.

Thanks

-jahn