NS2 IEEE802.15.4 Scripting Confusion

Good day,
Kindly help / point me to the right direction in making all the nodes send packets to the sink and receive acknowledgement in return. It appears only few nodes are communicating with the sink node. suggestions for the modification will be highly appreciated.

secondly, what does the"apptime(1)" syntax mean or do? I have been trying to understand what exactly is going on in the script but it is confusing, i will appreciate any documentation to help educate my ignorance.

Code:# ======================================================================
# Define options
# ======================================================================
set val(chan) Channel/WirelessChannel ;# Channel Type
set val(prop) Propagation/TwoRayGround ;# radio-propagation model
set val(netif) Phy/WirelessPhy/802_15_4
set val(mac) Mac/802_15_4
set val(ifq) Queue/DropTail/PriQueue ;# interface queue type
set val(ll) LL ;# link layer type
set val(ant) Antenna/OmniAntenna ;# antenna model
set val(ifqlen) 100000 ;# max packet in ifq
set val(nn) 41 ;# number of mobilenodes
set val(rp) DumbAgent ;# routing protocol
set val(x) 50
set val(y) 50

set val(nam) beacon_enabled_star.nam
set val(traffic) ftp ;# cbr/poisson/ftp

#read command line arguments
proc getCmdArgu {argc argv} {
global val
for {set i 0} {$i < $argc} {incr i} {
set arg [lindex $argv $i]
if {[string range $arg 0 0] != "-"} continue
set name [string range $arg 1 end]
set val($name) [lindex $argv [expr $i+1]]
}
}
getCmdArgu $argc $argv

for {set i 1} {$i<[expr $val(nn)]} {incr i} {
set appTime($i) [expr 30+($i-1)*1]
}

set stopTime 200 ;# in seconds

# Initialize Global Variables
set ns_ [new Simulator]
set tracefd [open ./beacon_enabled_star.tr w]
$ns_ trace-all $tracefd
if { "$val(nam)" == "beacon_enabled_star.nam" } {
set namtrace [open ./$val(nam) w]
$ns_ namtrace-all-wireless $namtrace $val(x) $val(y)
}

$ns_ puts-nam-traceall {# nam4wpan #} ;# inform nam that this is a trace file for wpan (special handling needed)

Mac/802_15_4 wpanCmd verbose on
Mac/802_15_4 wpanNam namStatus on ;# default = off (should be turned on before other 'wpanNam' commands can work)
#Mac/802_15_4 wpanNam ColFlashClr gold ;# default = gold

# For model 'TwoRayGround'
set dist(5m) 7.69113e-06
set dist(9m) 2.37381e-06
set dist(10m) 1.92278e-06
set dist(11m) 1.58908e-06
set dist(12m) 1.33527e-06
set dist(13m) 1.13774e-06
set dist(14m) 9.81011e-07
set dist(15m) 8.54570e-07
set dist(16m) 7.51087e-07
set dist(20m) 4.80696e-07
set dist(25m) 3.07645e-07
set dist(30m) 2.13643e-07
set dist(35m) 1.56962e-07
set dist(40m) 1.20174e-07
Phy/WirelessPhy set CSThresh_ $dist(25m)
Phy/WirelessPhy set RXThresh_ $dist(25m)

# set up topography object
set topo [new Topography]
$topo load_flatgrid $val(x) $val(y)

# Create God
set god_ [create-god $val(nn)]

set chan_1_ [new $val(chan)]

# configure node

$ns_ node-config -adhocRouting $val(rp) \
-llType $val(ll) \
-macType $val(mac) \
-ifqType $val(ifq) \
-ifqLen $val(ifqlen) \
-antType $val(ant) \
-propType $val(prop) \
-phyType $val(netif) \
-topoInstance $topo \
-agentTrace OFF \
-routerTrace OFF \
-macTrace ON \
-movementTrace OFF \
-energyModel "EnergyModel" \
-initialEnergy 1000 \
-rxPower 35.28e-3 \
-txPower 31.32e-3 \
-idlePower 712e-6 \
-sleepPower 144e-9 \
-channel $chan_1_

for {set i 0} {$i < 1 } {incr i} {
set node_($i) [$ns_ node]
$node_($i) random-motion 0 ;# disable random motion
}

$ns_ node-config -adhocRouting $val(rp) \
-llType $val(ll) \
-macType $val(mac) \
-ifqType $val(ifq) \
-ifqLen 2 \
-antType $val(ant) \
-propType $val(prop) \
-phyType $val(netif) \
-topoInstance $topo \
-agentTrace OFF \
-routerTrace OFF \
-macTrace ON \
-movementTrace OFF \
-energyModel "EnergyModel" \
-initialEnergy 1000 \
-rxPower 35.28e-3 \
-txPower 31.32e-3 \
-idlePower 712e-6 \
-sleepPower 144e-9 \
-channel $chan_1_

for {set i 1} {$i < $val(nn) } {incr i} {
set node_($i) [$ns_ node]
$node_($i) random-motion 0 ;# disable random motion
}

#source ./wpan_demo2_iy.scn

############### FORTKN0X ###############################

for {set i 1} {$i <$val(nn)} {incr i} {
set YY [expr 25*sin($i*(360/($val(nn)-1))*0.017460317 + 25)]
set XX [expr 25*cos($i*(360/($val(nn)-1))*0.017460317 + 25)]

$node_($i) set X_ $XX
$node_($i) set Y_ $YY
$node_($i) set Z_ 0.00
}

####################################################

$ns_ at 0.0 "$node_(0) NodeLabel PAN Coor"
$ns_ at 0.0 "$node_(0) sscs startPANCoord 1 6 6" ;# startPANCoord <txBeacon=1> <BO=3> <SO=3>
for {set i 1} {$i <$val(nn)} {incr i} {
$ns_ at [expr 5+$i-1] "$node_($i) sscs startDevice 0 0"
}

#$ns_ at 0.5 "$node_(1) sscs startDevice 0 0" ;# startDevice <isFFD=1> <assoPermit=1> #<txBeacon=0> <BO=3> <SO=3>
#$ns_ at 1.5 "$node_(2) sscs startDevice 0 0"
#$ns_ at 2.5 "$node_(3) sscs startDevice 0 0"
#$ns_ at 3.5 "$node_(4) sscs startDevice 0 0"
#$ns_ at 4.5 "$node_(5) sscs startDevice 0 0"
#$ns_ at 5.5 "$node_(6) sscs startDevice 0 0"

Mac/802_15_4 wpanNam PlaybackRate 3ms

$ns_ at $appTime(1) "puts \"\nTransmitting data ...\n\""

# Setup traffic flow between nodes

proc cbrtraffic { src dst interval starttime } {
global ns_ node_
set udp_($src) [new Agent/UDP]
eval $ns_ attach-agent \$node_($src) \$udp_($src)
set null_($dst) [new Agent/Null]
eval $ns_ attach-agent \$node_($dst) \$null_($dst)
set cbr_($src) [new Application/Traffic/CBR]
eval \$cbr_($src) set packetSize_ 40
eval \$cbr_($src) set interval_ $interval
eval \$cbr_($src) set random_ 0
#eval \$cbr_($src) set maxpkts_ 10000
eval \$cbr_($src) attach-agent \$udp_($src)
eval $ns_ connect \$udp_($src) \$null_($dst)
$ns_ at $starttime "$cbr_($src) start"
}

proc poissontraffic { src dst interval starttime} {
global ns_ node_
set udp($src) [new Agent/UDP]
eval $ns_ attach-agent \$node_($src) \$udp($src)
set null($dst) [new Agent/Null]
eval $ns_ attach-agent \$node_($dst) \$null($dst)
set expl($src) [new Application/Traffic/Exponential]
eval \$expl($src) set packetSize_ 117
eval \$expl($src) set burst_time_ 0
eval \$expl($src) set idle_time_ [expr $interval*1000.0-117.0*8/250]ms ;# idle_time + pkt_tx_time = interval
eval \$expl($src) set rate_ 250k
eval \$expl($src) attach-agent \$udp($src)
eval $ns_ connect \$udp($src) \$null($dst)
$ns_ at $starttime "$expl($src) start"
}

if { ("$val(traffic)" == "cbr") || ("$val(traffic)" == "poisson") } {
puts "\nTraffic: $val(traffic)"
#Mac/802_15_4 wpanCmd ack4data on
puts [format "Acknowledgement for data: %s" [Mac/802_15_4 wpanCmd ack4data off]]

for {set i 1} {$i <$val(nn)} {incr i} {
$val(traffic)traffic $i 0 .208 $appTime([expr $i])
}

Mac/802_15_4 wpanNam FlowClr -p AODV -c tomato
Mac/802_15_4 wpanNam FlowClr -p ARP -c green
Mac/802_15_4 wpanNam FlowClr -p MAC -s 0 -d -1 -c navy
if { "$val(traffic)" == "cbr" } {
set pktType cbr
} else {
set pktType exp
}
Mac/802_15_4 wpanNam FlowClr -p $pktType -s 0 -d 1 -c blue
}

proc ftptraffic { src dst starttime } {
global ns_ node_
set tcp($src) [new Agent/TCP]
eval \$tcp($src) set packetSize_ 50
set sink($dst) [new Agent/TCPSink]
eval $ns_ attach-agent \$node_($src) \$tcp($src)
eval $ns_ attach-agent \$node_($dst) \$sink($dst)
eval $ns_ connect \$tcp($src) \$sink($dst)
set ftp($src) [new Application/FTP]
eval \$ftp($src) attach-agent \$tcp($src)
$ns_ at $starttime "$ftp($src) start"
}

if { "$val(traffic)" == "ftp" } {
puts "\nTraffic: ftp"
#Mac/802_15_4 wpanCmd ack4data off
puts [format "Acknowledgement for data: %s" [Mac/802_15_4 wpanCmd ack4data]]

$ns_ at $appTime(1) "Mac/802_15_4 wpanNam PlaybackRate 0.20ms"

$ns_ at [expr $appTime(1) + 0.5] "Mac/802_15_4 wpanNam PlaybackRate 1.5ms"

#ftptraffic 0 1 $appTime1
ftptraffic 0 1 $appTime(1)
#ftptraffic 0 1 $appTime([expr $i-1])

$ns_ at $appTime(1) "$ns_ trace-annotate \"(at $appTime(1)) ftp traffic from node 0 to node 1\""

Mac/802_15_4 wpanNam FlowClr -p AODV -c tomato
Mac/802_15_4 wpanNam FlowClr -p ARP -c green
Mac/802_15_4 wpanNam FlowClr -p MAC -s 0 -d -1 -c navy
Mac/802_15_4 wpanNam FlowClr -p tcp -s 0 -d 1 -c blue
Mac/802_15_4 wpanNam FlowClr -p ack -s 1 -d 0 -c blue
}

# defines the node size in nam
for {set i 0} {$i < $val(nn)} {incr i} {
$ns_ initial_node_pos $node_($i) 2
}

# Tell nodes when the simulation ends
for {set i 0} {$i < $val(nn) } {incr i} {
$ns_ at $stopTime "$node_($i) reset";
}

$ns_ at $stopTime "stop"
$ns_ at $stopTime "puts \"NS EXITING...\n\""
$ns_ at $stopTime "$ns_ halt"

proc stop {} {
global ns_ tracefd appTime1 val env
$ns_ flush-trace
close $tracefd
set hasDISPLAY 0
foreach index [array names env] {
#puts "$index: $env($index)"
if { ("$index" == "DISPLAY") && ("$env($index)" != "") } {
set hasDISPLAY 1
}
}
if { ("$val(nam)" == "beacon_enabled_star.nam") && ("$hasDISPLAY" == "1") } {
exec nam beacon_enabled_star.nam &
}
}

puts "\nStarting Simulation..."
$ns_ run