Re: Wireless Simulation

["Samir R. Das" <samir@cs.utsa.edu>]

  >>Hi all,
  >>
  >>I have tried the example file ~tcl/ex/wireless.tcl in ns-allione-2.1b5
  >>(I'm a solaris user).
  >>With the given connection pattern ~tcl/mobility/scene/cbr-50-20-4-512
  >>and the scenario
  >>~tcl/mobility/scene/scen-670x670-50-600-20, the output looks quite nice,
  >>the 50 nodes seem to move around. My problem is now, how to get any
  >>traffic into the simulation?
  >>I've looked into the connection pattern file, and it seems that traffic
  >>is generated when
  >>simulation has already stopped. I tried to extend the simulation time,
  >>but this was giving
  >>me "Segmentation fault", maybe because of too many movements causing too
  >>many lines in the output?

Are you using DSDV? I have also seen segmentation faults with DSDV.
So something is definitely wrong.

After looking into the code I suspect that there is some problem
with the integration of the CMU codes in ns. See my post from yesterday.

But, I have not explored whether the seg. fault is because of this?


  >>I tried to change the times scheduled in the connection pattern file
  >>then, but there were
  >>only three packets of one connection visible in the trace file.
  >>How can I generate traffic of any kind for the mobility scenario?
  >>Anyway, is there some help about what lines in mobility trace files
  >>mean?
  
  >>One more problem, when I tried to switch the logging of movement off,
  >>there was the
  >>following error:
  >>can't read "ns": no such variable
  >>while executing
  >>"set ns_ $ns"
  >>(procedure "dsdv-create-mobile-node" line 5)
  >>invoked from within
  >>"dsdv-create-mobile-node $i"
  >>(file "wireless.tcl" line 250)
  >>I've looked at line 250, but it seemed like a normal loop to me and I
  >>can't make anything out of the error. I didn't change anything there, I
  >>just set opt(lm) to "off".
  
This is not hard to fix. In the test suite  somehow some initializations
happen only if opt(lm) is "on". This is incorrect, but is easily fixable.
Try to follow the tcl code. 

I have fixed this. I can send my code to you, if you wish.
But my code now includes some custom stuff, so may not run out
of the box in your installation.

Samir Das


>>Maybe someone can help me who has tried the example wireless.tcl and
  >>give me a hint how I can do a wireless simulation with the mobility
  >>code.
  >>
  >>Thanks in advance,
  >>
  >>Verena