Re: [ns] random seed for Application/Traffic

[Martin Koyabe <koyabe@erg.abdn.ac.uk>]

Some help or clarification needed regarding satnode !!


1) Suppose I have a scenario where the forward path is 2 Mb/s and a return path of 64Kb/s.
i.e. scenario 1: terminal----2Mb/s---->satellite-----2Mb/s------>terminal and
     scenario 2: terminal<---64Kb/s----satellite<----64Kb/s------terminal

 How does one go about setting these parameters ? The only examples available show 

   set opt(bw_up)   2Mb  (terminal - sat)
   set opt(bw_down) 2Mb  (sat - terminal)

which I presume is scenario 1 !!!      


2) In ~/tcl/ex/sat-aloha.tcl lines 67 - 76 below

-----
# GEO satellite at 0 degrees longitude 
set n1 [$ns satnode-geo-repeater 0 $opt(chan)]

# Place 100 nodes at 100 different locations
set num_nodes		100
for {set a 1} {$a <= $num_nodes} {incr a} {
	set n($a) [$ns satnode-terminal [expr -15 + $a * 0.3] [expr 15 - $a * 0.3] ]
	$n($a) add-gsl geo $opt(ll) $opt(ifq) $opt(qlim) $opt(mac) $opt(bw_up) \
  		$opt(phy) [$n1 set downlink_] [$n1 set uplink_]
}
------

Q) Why is node n1 set to [$ns satnode-terminal ...] in the for-loop while it has already 
been assigned to satnode-geo-repeater

Q) If wrong, should the for-loop then look like this

   for {set a 2} {$a <= $num_nodes} {incr a} { ... }
   
   
 
-- Martin