v-scenario.tcl

对IEEE 802.11e里的分布式信道接入算法EDCA进行改进

#
# SCENARIO:
#
# either 10, 20, or 30 terminals (e.g. stations, nodes) arranged
# as pairs with bidirectional communication flows between them.
# For each pair of nodes the load in one direction is to be 2X
# the load in the opposite direction.
# 
# The entire load consists of 1504 byte packets.
# Each traffic source at each node is an exponential generator.
# [note: this is a very artificial load]
# [question: if I give my model 1504 byte packets (including the frame
#	header) it will also simulate preamble time and PLCP.  Does
#	Opnet do this? Or should I compensate for OpNet by using a
#	smaller packet size?
# [please verify as this could skew the comparitive results]
# 
# The PHY is 11Mb/s with retry limit set to 7.
# There is no topology model, meaning no hidden or weak stations.
# There is no channel model, meaning all transmission errors are caused
# by collisions (transmission attempts).
# 
# There are three traffic classes: Low, Medium, High (L, M, H).
# The three classes are meant to split the total load such that a higher
# traffic class gets 2X the bandwidth of the next lower TC.
# 
# There are three 30-second time segments in the simulation run.
# The total load and its distribution across traffic classes will be:
# 
# segment         load            stations
# 
# 0-30s           3Mb/s           H=6  M=4  L=0   total=10
# 30-60s          6Mb/s           H=6  M=6  L=8   total=20
# 60-90s          9Mb/s           H=10 M=10 L=10  total=30
#
# The above works out to inter-arrival time per pkt on the fast sender of:
#		   H		   M		   L
# 0-30s		27.072ms	36.096ms	   x
# 30-60s	15.792ms	31.584ms	84.224ms
# 60-90s	17.547ms	35.093ms	70.187ms
#
# Added hybrid nodes:
#	First 30 nodes are as per above scenario
#	Rest use hybrid mode
#

# defaults
#set num_nodes			30  ///loulou comments it
set num_bss_nodes		0
set endtime			93.0
Phy/WirelessPhy set CPThresh_	99999
Mac/802_11 set bandwidth_	11Mb
PLevels set max_plevels_	4
PLevels set plevels_		4
MAC_MIB set RTSThreshold_	3000
MAC_MIB set ShortRetryLimit_	7
MAC_MIB set LongRetryLimit_	4
PHY_MIB set MinimumBandwidth_	1Mb
PHY_MIB set SlotTime_		0.000020
PHY_MIB set SIFS_		0.000010
PHY_MIB set CWMin_0		7
PHY_MIB set CWMin_1		31
PHY_MIB set CWMin_2		63
PHY_MIB set CWMin_3		127
PHY_MIB set CWOffset_0		0
PHY_MIB set CWOffset_1		0
PHY_MIB set CWOffset_2		7
PHY_MIB set CWOffset_3		15
PHY_MIB set CWMax_0		1023
PHY_MIB set CWMax_1		1023
PHY_MIB set CWMax_2		1023
PHY_MIB set CWMax_3		1023
LL set delay_			0
set val(ifqlen)			166

proc create_scenario { } {
	global ns_ node_
	global num_nodes

	for {set i 0} {$i < 6} {incr i} {
		set time_($i) 3.0;
		set period_($i) 27.072
	}
	for { } {$i < 6} {incr i} {
		set time_($i) 33.0;
		set period_($i) 15.792
	}
	for { } {$i < 10} {incr i} {
		set time_($i) 63.0;
		set period_($i) 17.547
	}
	for { } {$i < 14} {incr i} {
		set time_($i) 3.0;
		set period_($i) 36.096
	}
	for { } {$i < 16} {incr i} {
		set time_($i) 33.0;
		set period_($i) 31.584
	}
	for { } {$i < 20} {incr i} {
		set time_($i) 63.0;
		set period_($i) 35.093
	}
	for { } {$i < 20} {incr i} {
		set time_($i) 3.0;
		set period_($i) 0
	}
	for { } {$i < 28} {incr i} {
		set time_($i) 33.0;
		set period_($i) 84.224
	}
	for { } {$i < 30} {incr i} {
		set time_($i) 63.0;
		set period_($i) 70.187
	}

	for {set i 1} {$i < 30} {incr i 2} {
		set period_($i) [expr 2 * $period_($i)]
	}

	for {set i 0} {$i < 30} {incr i} {
		set src_node $node_($i)
		set sink_node $node_([expr $i + 1 - (2 * ($i % 2))])

		set src [new Agent/UDP]
		$src set class_ [expr 10 + $i]
		$src set prio_ [expr $i / 10]
		$src set packetSize_ 1476
		$ns_ attach-agent $src_node $src

		set sink [new Agent/UDP]
		$ns_ attach-agent $sink_node $sink

		$ns_ connect $src $sink

		set generator_($i) [new Application/Traffic/CBR]
		$generator_($i) set random_ 42
		$generator_($i) set packetSize_ 1476
		$generator_($i) set interval_ [expr $period_($i)]ms
		$generator_($i) attach-agent $src

		$ns_ at $time_($i) "$generator_($i) start"
	}

	for {set i 0} {$i < 6} {incr i 2} {
		$ns_ at 33.0 "$generator_($i) set interval_ 15.792ms"
		$ns_ at 63.0 "$generator_($i) set interval_ 17.547ms"
	}
	for { } {$i < 6} {incr i 2} {
		$ns_ at 63.0 "$generator_($i) set interval_ 17.547ms"
	}
	for { } {$i < 10} {incr i 2} {
	}
	for { } {$i < 14} {incr i 2} {
		$ns_ at 33.0 "$generator_($i) set interval_ 31.584ms"
		$ns_ at 63.0 "$generator_($i) set interval_ 35.093ms"
	}
	for { } {$i < 16} {incr i 2} {
		$ns_ at 63.0 "$generator_($i) set interval_ 35.093ms"
	}
	for { } {$i < 20} {incr i 2} {
	}
	for { } {$i < 20} {incr i 2} {
		$ns_ at 33.0 "$generator_($i) set interval_ 84.224ms"
		$ns_ at 63.0 "$generator_($i) set interval_ 70.187ms"
	}
	for { } {$i < 28} {incr i 2} {
		$ns_ at 63.0 "$generator_($i) set interval_ 70.187ms"
	}
	for { } {$i < 30} {incr i 2} {
	}

	for {set i 1} {$i < 6} {incr i 2} {
		$ns_ at 33.0 "$generator_($i) set interval_ 31.584ms"
		$ns_ at 63.0 "$generator_($i) set interval_ 35.094ms"
	}
	for { } {$i < 6} {incr i 2} {
		$ns_ at 63.0 "$generator_($i) set interval_ 35.094ms"
	}
	for { } {$i < 10} {incr i 2} {
	}
	for { } {$i < 14} {incr i 2} {
		$ns_ at 33.0 "$generator_($i) set interval_ 63.168ms"
		$ns_ at 63.0 "$generator_($i) set interval_ 70.187ms"
	}
	for { } {$i < 16} {incr i 2} {
		$ns_ at 63.0 "$generator_($i) set interval_ 70.187ms"
	}
	for { } {$i < 20} {incr i 2} {
	}
	for { } {$i < 20} {incr i 2} {
		$ns_ at 33.0 "$generator_($i) set interval_ 168.448ms"
		$ns_ at 63.0 "$generator_($i) set interval_ 140.374ms"
	}
	for { } {$i < 28} {incr i 2} {
		$ns_ at 63.0 "$generator_($i) set interval_ 140.374ms"
	}
	for { } {$i < 30} {incr i 2} {
	}

	# hybrid nodes
	for {set i 30} {$i < $num_nodes} {incr i 2} {
		set src_node $node_($i)
		set sink_node $node_([expr $i + 1])
		$src_node setMac CWMin 0
		$src_node setMac difs -1

		set src [new Agent/UDP]
		$src set class_ 40
		$src set prio_ 0
		$src set packetSize_ 1476
		$ns_ attach-agent $src_node $src

		set sink [new Agent/UDP]
		$ns_ attach-agent $sink_node $sink

		$ns_ connect $src $sink

		set generator_($i) [new Application/Traffic/CBR]
		$generator_($i) set random_ 42
		$generator_($i) set packetSize_ 1476
		$generator_($i) set interval_ 30.0ms
		$generator_($i) attach-agent $src

		$ns_ at 3.0 "$generator_($i) start"
	}
}