Re: [ns] Error Model in Wireless Network

["Nikolaos Katsarakis Austauschstud. (M. Schweigel)" <katsarak@ifn.et.tu-dresden.de>]

It is possible to change the link bandwidth on the fly (haven't tested it yet, but it should work) using the command

$ns_ at 2.0 "$ns_ bandwidth $node_(r1) $node_(k1) 8Kb duplex"

for more information look at the /ns/tcl/test/test-suite-links.tcl

Nick

jahn-isi wrote:

> 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