Re: [ns] Phy/WirelessPhy set Rb_ 2*1e6 ??????? (fwd)

[Vikas Kawadia <vikas@indore.csl.uiuc.edu>]

hi Vikram,

If bandwidth has been moved to phy.{cc,h}, the files in tcl/ex and
tcl/test should use a set bandwidth_ and not set Rb_ . What say?

btw, it seems this message of yours never got to the list becuase it
was your first after they started sending that faq new people. I am
inclkuding it in here.

..vikas

Date: Mon, 25 Dec 2000 13:01:12 -0600 (CST)
From: Vikram Kanodia <kanodia@ece.rice.edu>
To: kawadia@uiuc.edu
Cc: ns-users@ISI.EDU
Subject: Re: [ns] Phy/WirelessPhy set Rb_ 2*1e6 ???????


I agree....I have been using the original cmu extensions for mobile
networks (implemented for ns2.1b3) and their file named
sharedmedia.{cc,h}
(which is equivalent to wireless-phy.{cc,h} in ns2.1b6) has the parameter
Rb instead of bandwidth...... 

below is the snippet of their code:

as can be seen from their code everything in wireless-phy.cc is same as
theirs but for the parameter Rb/bandwidth.....maybe someone changed this
parameter to bandwidth in the .cc files but forgot to change in .tcl
file...

hope this helps...but i would love to know the exact answer too :)

-Vikram


SharedMedia::SharedMedia(void) : NetIf()
{  
  Rb = 2*1e6;		                  // 2 Mb
  Pt = pow(10, 2.45) * 1e-3;		  // 24.5 dbm, ~ 281.8mw
  lambda = SPEED_OF_LIGHT / (914 * 1e6);  // 914 mHz
  L = 1.0;
  freq = -1.0;

  /*
   *  It sounds like 10db should be the capture threshold.
   *
   *  If a node is presently receiving a packet a a power level
   *  Pa, and a packet at power level Pb arrives, the following
   *  comparion must be made to determine whether or not capture
   *  occurs:
   *
   *    10 * log(Pa) - 10 * log(Pb) > 10db
   *
   *  OR equivalently
   *
   *    Pa/Pb > 10.
   *
   */
  CPThresh = 10.0;
  CSThresh = 1.559e-11;
  RXThresh = 3.652e-10;

  bind("CPThresh_", &CPThresh);
  bind("CSThresh_", &CSThresh);
  bind("RXThresh_", &RXThresh);
  bind("Rb_", &Rb);
  bind("Pt_", &Pt);
  bind("freq_", &freq);
  bind("L_", &L);

  if (freq != -1.0) 
    { // freq was set by tcl code
      lambda = SPEED_OF_LIGHT / freq;
    }
}


>   I am quite puzzled by this. This variable Rb_ is set to 2Megs in a
> bunch of example and test files (in tcl/ex and tcl/test directories) using
> Phy/WirelessPhy set Rb_ 2*1e6. But quite astonishinlgy no such variable
> has been defined in wireless-phy.{cc,h} or any other file for that matter.
> It is there in phy.cc but the corresponding code is masked. Looking thru
> wireless-phy.cc it seems that set Rb_ should be actually set bandwidth_
>  Here is the grep output in the ns_tree
> 
> 
> [vikas@indore ns-2.1b7]$ grep -r Rb_ *
> Binary file linkstate/ls.o matches
> Binary file linkstate/rtProtoLS.o matches
> Binary file ns matches
> phy.cc:// 	return hdr->size() * 8.0 /Rb_;   ----->> this is masked ! 
> tcl/ex/PIdemo/estudy.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/diffusion-prob-run.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/diffusion-rate-run.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/flooding-run.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/grid2.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/gridkeeper.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/omni-run.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/wired-cum-wireless-sim.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/wireless-demo-csci694.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/wireless-dsdv-newnode.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/wireless-landmark.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/wireless-mip-test.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/wireless-newnode-energy.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/wireless-pkt-demo.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/wireless-test.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/wireless.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/ex/vikas-wireless-pkt-demo.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/test/test-suite-energy.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/test/test-suite-wireless-diffusion.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/test/test-suite-wireless-gridkeeper.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/test/test-suite-wireless-lan-aodv.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/test/test-suite-wireless-lan-newnode.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/test/test-suite-wireless-lan-tora.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/test/test-suite-wireless-lan.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> tcl/test/test-suite-wireless-tdma.tcl:Phy/WirelessPhy set Rb_ 2*1e6
> 
> 
> 
> ..vikas
> 
> 


Department of ECE, Rice University | 713 348 3786 (O)| 713 664 5650(H)
http://www.ece.rice.edu/~kanodia