back_video.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


	
	set pri 0

# real ending time	
	set endtime 23
	set t 3
	set fl_id 0
	set rng  [new RNG]
	$rng uniform 0 2


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

	for {set i 0} {$i < [expr $num_nodes]} {incr i} {                
		
		
		#set start_time [expr $t + 4]
		
		set start_time [expr 5 + [$rng uniform 0 1]]
	  set  node_src	$i
		
	    if {$i < [expr $num_nodes - 1]} {
		 set  node_sink	[expr $i +1] 
		} else {
		  set  node_sink 0
		}
		
		if {$i < 2} {
		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 t [expr $t + 2]
	}
  incr pri 
	set t 3
###################	#########################
	
	# Setup Background flows

  puts "TCP and UDP priority is $pri"
	
	for {set i 0} { $i < $num_nodes} {incr i} {
	 
	 
	 set start_time [expr 5 + [$rng uniform 0 2]]
	  #set start_time [expr $t + 4]
		
		
	  set  node_src	$i
		
		if {$i < [expr $num_nodes - 1]} {
		 set  node_sink	[expr $i +1]
		 
		} else {
		  set  node_sink 0
		}
		if {$i < 2} {
		set finishtime  [expr $endtime - 0 ]
		} else {
		set finishtime  [expr $endtime - 0 ]
		}
	build-cbr $node_($node_src) $node_($node_sink) $pktsize $udp_interval 0 $fl_id $start_time $finishtime $pri
	#build-tcp "TCP" $node_($node_src) $node_($node_sink) $pktsize 20 $fl_id $start_time $endtime $fl_id $pri 	
		
		puts "B$i with pktsize $pktsize flows $fl_id  from Node$i to Node $node_sink every $udp_interval"	
		 	
			puts $start_time
		
		incr fl_id
		set t [expr $t + 2]
	}
}