Examples for CBR traffic transmission over DCF-based and EDCF-based wireless networks

 

[Preface]

1.      Before you run the examples below, please prepare some background for DCF and EDCF first.

2.      The examples are included in myNS2.

 

[Simulation Scripts]

 

DCF example

# globals and flags

set ns [new Simulator]

 

#number of nodes

set num_wired_nodes  1

set num_mobile_nodes 1

set num_bs_nodes     1 ;# number of base stations

set num_nodes [expr $num_wired_nodes + $num_mobile_nodes + $num_bs_nodes]

set bs_id $num_wired_nodes

 

# Parameter for wireless nodes

set opt(chan)           Channel/WirelessChannel    ;# channel type

set opt(prop)           Propagation/TwoRayGround   ;# radio-propagation model

set opt(netif)          Phy/WirelessPhy            ;# network interface type

set opt(mac)            Mac/802_11                 ;# MAC type

set opt(ifq)            Queue/DropTail/PriQueue    ;# interface queue type

set opt(ifqlen)         50

set opt(ll)             LL                         ;# link layer type

set opt(ant)            Antenna/OmniAntenna        ;# antenna model

set opt(ifqlen)         50                        ;# max packet in ifq

set opt(adhocRouting)   NOAH                       ;# routing protocol

set opt(x)          670  ;# X dimension of the topography

set opt(y)          670          ;# Y dimension of the topography

 

#smallko add the following two lines

Mac/802_11 set dataRate_  1Mb

Mac/802_11 set basicRate_  1Mb

 

#set up for hierarchical routing

#(needed for routing over a basestation)

$ns node-config -addressType hierarchical

AddrParams set domain_num_ 2          ;# domain number

lappend cluster_num 1 1               ;# cluster number for each domain

AddrParams set cluster_num_ $cluster_num

lappend eilastlevel $num_wired_nodes [expr $num_mobile_nodes + $num_bs_nodes] ;# number of nodes for each cluster            

AddrParams set nodes_num_ $eilastlevel

 

#Open the nam trace file

set nf [open out.nam w]

$ns namtrace-all-wireless $nf $opt(x) $opt(y)

set ntr [open out.tr w]

$ns trace-all $ntr

 

set chan    [new $opt(chan)]

set topo    [new Topography]

$topo load_flatgrid $opt(x) $opt(y)

 

# Create God

create-god [expr $num_mobile_nodes + $num_bs_nodes]

 

# creating wired nodes

for {set i 0} {$i < $num_wired_nodes} {incr i} {

        set W($i) [$ns node 0.0.$i]

    puts "wired node $i created"

}

 

 

# creating base station

$ns node-config -adhocRouting $opt(adhocRouting) \

                 -llType $opt(ll) \

                 -macType $opt(mac) \

                 -ifqType $opt(ifq) \

                 -ifqLen $opt(ifqlen) \

                 -antType $opt(ant) \

                 -propType $opt(prop)    \

                 -phyType $opt(netif) \

                 -channel $chan      \

                 -topoInstance $topo \

                 -wiredRouting ON \

                 -agentTrace OFF \

                 -routerTrace OFF \

                 -macTrace OFF    \

                 -movementTrace OFF

 

set BS(0) [$ns node 1.0.0]

$BS(0) random-motion 0

puts "Base-Station node $bs_id created"

#provide some co-ord (fixed) to base station node

$BS(0) set X_ 1.0

$BS(0) set Y_ 2.0

$BS(0) set Z_ 0.0

 

# creating mobile nodes

$ns node-config -wiredRouting OFF

for {set i 0} {$i < $num_mobile_nodes} {incr i} {

    set wl_node_($i) [$ns node 1.0.[expr $i + 1]]  

        $wl_node_($i) random-motion 0               ;# disable random motion

    puts "wireless node $i created ..."

    $wl_node_($i) base-station [AddrParams addr2id [$BS(0) node-addr]]

    $wl_node_($i) set X_ [expr $i * 10]

    $wl_node_($i) set Y_ [expr $i * 10]

    $wl_node_($i) set Z_ 0.0

}

 

# linking of root to base-station node

$ns duplex-link $W(0) $BS(0) 10Mb 2ms DropTail

 

# linking of wired nodes to root node

#for {set i 1} {$i < $num_wired_nodes} {incr i} {

#    $ns duplex-link $W($i) $W(0) 10Mb 2ms DropTail

#}

 

set src_udp0 [new Agent/UDP]

$src_udp0 set class_ 0

#$src_udp0 set prio_ 0

set dst_udp0 [new Agent/Null]

$ns attach-agent $wl_node_(0) $src_udp0

$ns attach-agent $W(0) $dst_udp0

set app0 [new Application/Traffic/CBR]

$app0 attach-agent $src_udp0

$ns connect $src_udp0 $dst_udp0

$ns at 0.0 "$app0 start"

 

set src_udp1 [new Agent/UDP]

$src_udp1 set class_ 1

#$src_udp1 set prio_ 1

set dst_udp1 [new Agent/Null]

$ns attach-agent $wl_node_(0) $src_udp1

$ns attach-agent $W(0) $dst_udp1

set app1 [new Application/Traffic/CBR]

$app1 attach-agent $src_udp1

$ns connect $src_udp1 $dst_udp1

$ns at 0.3 "$app1 start"

 

set src_udp2 [new Agent/UDP]

$src_udp2 set class_ 2

#$src_udp2 set prio_ 2

set dst_udp2 [new Agent/Null]

$ns attach-agent $wl_node_(0) $src_udp2

$ns attach-agent $W(0) $dst_udp2

set app2 [new Application/Traffic/CBR]

$app2 attach-agent $src_udp2

$ns connect $src_udp2 $dst_udp2

$ns at 0.1 "$app2 start"

 

set src_udp3 [new Agent/UDP]

$src_udp3 set class_ 3

#$src_udp3 set prio_ 3

set dst_udp3 [new Agent/Null]

$ns attach-agent $wl_node_(0) $src_udp3

$ns attach-agent $W(0) $dst_udp3

set app3 [new Application/Traffic/CBR]

$app3 attach-agent $src_udp3

$ns connect $src_udp3 $dst_udp3

$ns at 0.2 "$app3 start"

 

# Define node initial position in nam

for {set i 0} {$i < $num_mobile_nodes} {incr i} {

    $ns initial_node_pos $wl_node_($i) 20

   }

 

# Tell nodes when the simulation ends

for {set i 0} {$i < $num_mobile_nodes } {incr i} {

    $ns at 10.0 "$wl_node_($i) reset";

}

 

$ns at 100.0 "$BS(0) reset";

$ns at 100.0 "$app0 stop"

$ns at 100.0 "$app1 stop"

$ns at 100.0 "$app2 stop"

$ns at 100.0 "$app3 stop"

$ns at 110.0 "puts \"NS EXITING...\" ; $ns halt"

 

proc stop {} {

    global ns ntr nf

    close $ntr

    close $nf

}

 

# run the simulation

$ns run

 

EDCF example (The differences are marked with RED color)

# globals and flags

set ns [new Simulator]

 

#number of nodes

set num_wired_nodes  1

set num_mobile_nodes 1

set num_bs_nodes     1 ;# number of base stations

set num_nodes [expr $num_wired_nodes + $num_mobile_nodes + $num_bs_nodes]

set bs_id $num_wired_nodes

 

# Parameter for wireless nodes

set opt(chan)           Channel/WirelessChannel    ;# channel type

set opt(prop)           Propagation/TwoRayGround   ;# radio-propagation model

set opt(netif)          Phy/WirelessPhy            ;# network interface type

set opt(mac)            Mac/802_11e                ;# MAC type

set opt(ifq)            Queue/DTail/PriQ           ;# interface queue type

set opt(ifqlen)         50

set opt(ll)             LL                         ;# link layer type

set opt(ant)            Antenna/OmniAntenna        ;# antenna model

set opt(ifqlen)         50                        ;# max packet in ifq

set opt(adhocRouting)   NOAH                      ;# routing protocol

set opt(x)          670  ;# X dimension of the topography

set opt(y)          670          ;# Y dimension of the topography

 

#smallko add the following two lines

Mac/802_11e set dataRate_  1Mb

Mac/802_11e set basicRate_ 1Mb

Mac/802_11e set backoff_mode_ 1

 

#set up for hierarchical routing

#(needed for routing over a basestation)

$ns node-config -addressType hierarchical

AddrParams set domain_num_ 2          ;# domain number

lappend cluster_num 1 1               ;# cluster number for each domain

AddrParams set cluster_num_ $cluster_num

lappend eilastlevel $num_wired_nodes [expr $num_mobile_nodes + $num_bs_nodes] ;# number of nodes for each cluster            

AddrParams set nodes_num_ $eilastlevel

 

#Open the nam trace file

set nf [open out.nam w]

$ns namtrace-all-wireless $nf $opt(x) $opt(y)

set ntr [open out.tr w]

$ns trace-all $ntr

 

set chan    [new $opt(chan)]

set topo    [new Topography]

$topo load_flatgrid $opt(x) $opt(y)

 

# Create God

create-god [expr $num_mobile_nodes + $num_bs_nodes]

 

# creating wired nodes

for {set i 0} {$i < $num_wired_nodes} {incr i} {

        set W($i) [$ns node 0.0.$i]

    puts "wired node $i created"

}

 

 

# creating base station

$ns node-config -adhocRouting $opt(adhocRouting) \

                 -llType $opt(ll) \

                 -macType $opt(mac) \

                 -ifqType $opt(ifq) \

                 -ifqLen $opt(ifqlen) \

                 -antType $opt(ant) \

                 -propType $opt(prop)    \

                 -phyType $opt(netif) \

                 -channel $chan      \

                 -topoInstance $topo \

                 -wiredRouting ON \

                 -agentTrace OFF \

                 -routerTrace OFF \

                 -macTrace OFF    \

                 -movementTrace OFF

 

set BS(0) [$ns node 1.0.0]

$BS(0) random-motion 0

puts "Base-Station node $bs_id created"

#provide some co-ord (fixed) to base station node

$BS(0) set X_ 1.0

$BS(0) set Y_ 2.0

$BS(0) set Z_ 0.0

 

# creating mobile nodes

$ns node-config -wiredRouting OFF

for {set i 0} {$i < $num_mobile_nodes} {incr i} {

                set wl_node_($i) [$ns node 1.0.[expr $i + 1]]  

                $wl_node_($i) random-motion 0               ;# disable random motion

    puts "wireless node $i created ..."

    $wl_node_($i) base-station [AddrParams addr2id [$BS(0) node-addr]]

    $wl_node_($i) set X_ [expr $i * 10]

    $wl_node_($i) set Y_ [expr $i * 10]

    $wl_node_($i) set Z_ 0.0

}

 

# linking of root to base-station node

$ns duplex-link $W(0) $BS(0) 10Mb 2ms DropTail

 

# linking of wired nodes to root node

#for {set i 1} {$i < $num_wired_nodes} {incr i} {

#    $ns duplex-link $W($i) $W(0) 10Mb 2ms DropTail

#}

 

set src_udp0 [new Agent/UDP]

$src_udp0 set class_ 0

# highest priority

$src_udp0 set prio_ 0

set dst_udp0 [new Agent/Null]

$ns attach-agent $wl_node_(0) $src_udp0

$ns attach-agent $W(0) $dst_udp0

set app0 [new Application/Traffic/CBR]

$app0 attach-agent $src_udp0

$ns connect $src_udp0 $dst_udp0

$ns at 0.0 "$app0 start"

 

set src_udp1 [new Agent/UDP]

$src_udp1 set class_ 1

$src_udp1 set prio_ 1

set dst_udp1 [new Agent/Null]

$ns attach-agent $wl_node_(0) $src_udp1

$ns attach-agent $W(0) $dst_udp1

set app1 [new Application/Traffic/CBR]

$app1 attach-agent $src_udp1

$ns connect $src_udp1 $dst_udp1

$ns at 0.3 "$app1 start"

 

set src_udp2 [new Agent/UDP]

$src_udp2 set class_ 2

$src_udp2 set prio_ 2

set dst_udp2 [new Agent/Null]

$ns attach-agent $wl_node_(0) $src_udp2

$ns attach-agent $W(0) $dst_udp2

set app2 [new Application/Traffic/CBR]

$app2 attach-agent $src_udp2

$ns connect $src_udp2 $dst_udp2

$ns at 0.1 "$app2 start"

 

set src_udp3 [new Agent/UDP]

#lowest priority

$src_udp3 set class_ 3

$src_udp3 set prio_ 3

set dst_udp3 [new Agent/Null]

$ns attach-agent $wl_node_(0) $src_udp3

$ns attach-agent $W(0) $dst_udp3

set app3 [new Application/Traffic/CBR]

$app3 attach-agent $src_udp3

$ns connect $src_udp3 $dst_udp3

$ns at 0.2 "$app3 start"

 

# Define node initial position in nam

for {set i 0} {$i < $num_mobile_nodes} {incr i} {

    $ns initial_node_pos $wl_node_($i) 20

   }

 

# Tell nodes when the simulation ends

for {set i 0} {$i < $num_mobile_nodes } {incr i} {

    $ns at 10.0 "$wl_node_($i) reset";

}

 

$ns at 100.0 "$BS(0) reset";

$ns at 100.0 "$app0 stop"

$ns at 100.0 "$app1 stop"

$ns at 100.0 "$app2 stop"

$ns at 100.0 "$app3 stop"

$ns at 110.0 "puts \"NS EXITING...\" ; $ns halt"

 

proc stop {} {

    global ns ntr nf

    close $ntr

    close $nf

}

 

# run the simulation

$ns run

 

[Running the simulation]

1.      change the path to ns-allinone-2.28/ns-2.28/mac/802_11e/example.

 

2.      Run the DCF example.

 

3.      Measure the throughput.

From the simulation results, we can find that 4 traffic flows almost equally share the bandwidth.

 

4.      Run the EDCF example.

 

5.      Measure the throughput

From the results, we can find that flow 0 (highest priority) gains the most part of bandwidth.

 

Last Modified Date : 2006/3/3

 

Author: Chih-Heng, Ke (柯志亨)

Email: smallko@ee.ncku.edu.tw

MSN: smallko@hotmail.com