set num_nodes 20
set max_nodes 25

set ns_ [new Simulator]

#Define different colors for data flows (for NAM)

$ns_ color 1 Blue
$ns_ color 2 Red
$ns_ color 3 yellow
$ns_ color 4 cyan
$ns_ color 5 brown
$ns_ color 6 purple
$ns_ color 7 green
$ns_ color 8 navy
$ns_ color 9 maroon
$ns_ color 10 black
$ns_ color 11 cornsilk
$ns_ color 12 lightcoral
$ns_ color 13 firebrick
$ns_ color 14 deeppink
$ns_ color 15 palevioletred
$ns_ color 16 coral
$ns_ color 17 lightsalmon


#Open the NAM trace file
set nf [open out.nam w]
$ns_ namtrace-all $nf

set tf [open tracefile.tr w]
$ns_ trace-all $tf
#define the finish procedure
proc finish {} {
global ns_ nf tf
$ns_ flush-trace
close $nf
close $tf
exec nam out.nam
exit 0
}

#declare two dimension array with MCS index

for {set i 1} {$i < $max_nodes } {incr i} {
for {set j 1} {$j < $max_nodes } {incr j} {

set MCSID_UERB($i$j) $j
puts "Assigned MCSID_UERB($i$j) code = $MCSID_UERB($i$j)"
}

}


#Create nodes
for {set i 0} {$i < $num_nodes} {incr i} {
set n_($i) [$ns_ node]
}


#Create links between the nodes
for {set i 1} {$i < $num_nodes } { incr i } {
$ns_ duplex-link $n_(0) $n_($i) 10Mb 5ms LTEQueue/DLAirQueue
}

#-------------QUEUE SIZE DESCRIPTION---------------#
$ns_ queue-limit $n_(0) $n_(1) 10


#label the BS
$ns_ at 0.0 "$n_(0) label BS"
$ns_ at 0.0 "$n_(0) add-mark m1 brown circle"


#label the nodes
for {set i 1} {$i < $num_nodes } {incr i } {
$ns_ at 0.0 "$n_($i) label UE$i"
$ns_ at 0.0 "$n_($i) color green"

}


#-----------Configuring nodes------------#
for {set i 1} {$i < $num_nodes } {incr i } {

#Setup a UDP connection
set udp_($i) [new Agent/UDP]
$ns_ attach-agent $n_(0) $udp_($i)
set null_($i) [new Agent/Null]
$ns_ attach-agent $n_($i) $null_($i)
$ns_ connect $udp_($i) $null_($i)
$udp_($i) set fid_ 1

#puts "null_($i)"
#Setup a CBR over UDP connection
set cbr_($i) [new Application/Traffic/CBR]
$cbr_($i) attach-agent $udp_($i)
$cbr_($i) set type_ CBR
$cbr_($i) set packet_size_ 1000
$cbr_($i) set rate_ 0.5mb
$cbr_($i) set random_ false

}

#assigning RB with BCS code

#$ns_ at 0.0 "$udp_(1) set fid_ 1"
#$ns_ at 0.0 "$udp_(2) set fid_ 4"
#$ns_ at 0.0 "$udp_(3) set fid_ 5"
#$ns_ at 0.0 "$udp_(4) set fid_ 7"
#$ns_ at 0.0 "$udp_(5) set fid_ 8"
#$ns_ at 0.0 "$udp_(6) set fid_ 2"
#$ns_ at 0.0 "$udp_(7) set fid_ 13"
#$ns_ at 0.0 "$udp_(8) set fid_ 19"
#$ns_ at 0.0 "$udp_(9) set fid_ 3"
#$ns_ at 0.0 "$udp_(10) set fid_ 5"
#$ns_ at 0.0 "$udp_(11) set fid_ 14"
#$ns_ at 0.0 "$udp_(12) set fid_ 16"
#$ns_ at 0.0 "$udp_(13) set fid_ 6"
#$ns_ at 0.0 "$udp_(14) set fid_ 17"
#$ns_ at 0.0 "$udp_(15) set fid_ 12"
#$ns_ at 0.0 "$udp_(16) set fid_ 18"
#$ns_ at 0.0 "$udp_(17) set fid_ 9"
#$ns_ at 0.0 "$udp_(18) set fid_ 11"
#$ns_ at 0.0 "$udp_(19) set fid_ 10"

#carrier allocation from array

for {set j 1} {$j < $num_nodes } {incr j } {

$ns_ at 0.2 "$udp_($j) set fid_ $MCSID_UERB(2$j)"

}
for {set j 1} {$j < $num_nodes } {incr j } {

$ns_ at 1.2 "$udp_($j) set fid_ $MCSID_UERB(3$j)"
}

for {set j 1} {$j < $num_nodes } {incr j } {

$ns_ at 2.2 "$udp_($j) set fid_ $MCSID_UERB(2$j)"
}


#Schedule events for the CBR and FTP agents
for {set j 1} {$j < $num_nodes } {incr j } {

$ns_ at 0.0 "$cbr_($j) start"
$ns_ at 3.2 "$cbr_($j) stop"

}
#call the finish procedure after 3 seconds of simulation time
$ns_ at 3.5 "finish"
#run the simulation
$ns_ run