scen_heterogen.tcl

对IEEE 802.11e里的分布式信道接入算法EDCA进行改进

#
# A wireless lan scenario with audio, video traffic over udp and background
# backlogged traffic(TCP, udp)
#
#

# defaults

#set ppktsize 1280				;# pktsize of phone streams
#set pinterval 5ms
set ppktsize 160				;# pktsize of phone streams
set pinterval 20ms

set vpktsize 1280				;# pktsize of video streams
set vinterval 10ms

set pktsize 200				;# pktsize for background traffic
set udp_interval 12.5ms

#set num_nodes [lindex $argv 0]	;#  number of mobilenodes in the scenario  ****lamia

source sources.tcl

global num_nodes

set num_bss_nodes 0				;# adhoc mode
PLevels set max_plevels_	3
PLevels set plevels_			3

PHY_MIB set CWMin_0				5
PHY_MIB set CWOffset_0		0
PHY_MIB set CWMax_0		   200           ;#Lamia

PHY_MIB set CWMin_1				15
PHY_MIB set CWOffset_1		0
PHY_MIB set CWMax_1				600                ;#Lamia

PHY_MIB set CWMin_2				31
PHY_MIB set CWOffset_2		0
PHY_MIB set CWMax_2				1023         ;#Lamia


# MAC_MIB set new_method 1  ;# ni: difs_i is used as DIFS= SIFS + i* Slot_time

set difs_0 1
set difs_1 2
set difs_2 3

proc create_scenario { } {
	global ns_ node_ num_nodes endtime
	global pnum ppktsize pinterval 
	global vnum vpktsize vinterval udp_interval 
	global pktsize


	if {$num_nodes > 3} {
	set sink_node [expr $num_nodes - 1]
	}
	set pri 0

# real ending time	
	set endtime 50
	set t 0
	set fl_id 0
	set rng  [new RNG]
	$rng uniform 0 1

##########################################################
	# Setup Phone flows

	for {set i 0} {$i <[expr $num_nodes ] } {incr i} {
	  
                #in oder to get right ARP and correct results, we need to start the simulation after 3 seconds

	        #set start_time 3;
                #This line is used if we change the station number dynamically
		set start_time [expr 3 + $t];
    
		set  node_src	$i
		
		if {$i < [expr $num_nodes - 1]} {
		 set  node_sink	[expr $i +1] 
		} else {
		  set  node_sink 0
		}
		
		if  { $i == 0} {  
		  set finishtime  [expr $endtime - 0 ]
		} else {
		  set finishtime  [expr $endtime - 0 ]
		} 
		
		build-cbr $node_($node_src) $node_($node_sink) $ppktsize $pinterval 0 $fl_id $start_time  $finishtime  $pri
		
		puts "P$i with pktsize $ppktsize flows $fl_id from Node$node_src to Node$node_sink every $pinterval"
    
		puts "node $i flow $fl_id's starting time is: $start_time"
		incr fl_id
		
                # interval is used for every this period we increase one station  
                set incr_interval 2 
		set t [expr $t + $incr_interval]
                #puts "interval is: $incr_interval"
	    }	
	set t 0
	incr pri

########################################################################################	
	
	# Setup Video flows

	for {set i 0} {$i < [expr $num_nodes]} {incr i} {                
		set start_time [expr 3 + $t];
		
	        set  node_src	$i
		
	        if {$i < [expr $num_nodes - 1]} {
		 set  node_sink	[expr $i +1] 
		} else {
		  set  node_sink 0
		}
		
		if  { $i == 0} {  
		  set finishtime  [expr $endtime - 0 ]
		} else {
		  set finishtime  [expr $endtime - 0 ]
		} 
		
		build-cbr $node_($node_src) $node_($node_sink) $vpktsize $vinterval 0 $fl_id $start_time  $finishtime $pri
		
		puts "V$i with pktsize $vpktsize flows $fl_id  from Node$i to Node $node_sink every $vinterval"
    
		puts $start_time
		incr fl_id
		
	        set incr_interval 2 
		set t [expr $t + $incr_interval]
	}
	
  set t 0
  incr pri 

}