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LoRaWAN.pl
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LoRaWAN.pl
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#!/usr/bin/perl -w
###################################################################################
# Event-based simulator for (un)confirmed LoRaWAN transmissions #
# v2024.1.14-EU868 #
# #
# Features: #
# -- Multiple half-duplex gateways #
# -- 1% radio duty cycle per band for the nodes #
# -- 1 or 10% radio duty cycle for the gateways #
# -- Acks with two receive windows (RX1, RX2) #
# -- Non-orthogonal SF transmissions #
# -- Periodic or non-periodic (exponential) transmission rate #
# -- Percentage of nodes required confirmed transmissions #
# -- Capture effect #
# -- Path-loss signal attenuation model (uplink+downlink) #
# -- Multiple channels #
# -- Collision handling for both uplink and downlink transmissions #
# -- Energy consumption calculation (uplink+downlink) #
# -- ADR support #
# -- Network server policies (downlink packet & gw selection) #
# #
# author: Dr. Dimitrios Zorbas #
# email: [email protected] #
# distributed under GNUv2 General Public Licence #
###################################################################################
use strict;
use POSIX;
use List::Util qw(min max sum);
use Time::HiRes qw(time);
use Math::Random qw(random_uniform random_exponential random_normal);
use Term::ProgressBar 2.00;
use GD::SVG;
use Statistics::Basic qw(:all);
die "usage: ./LoRaWAN.pl <packets_per_hour> <simulation_time(secs)> <gateway_selection_policy(0-5)> <terrain_file!>\n" unless (scalar @ARGV == 4);
die "Packet rate must be higher than or equal to 1pkt per hour\n" if ($ARGV[0] < 1);
die "Simulation time must be longer than or equal to 1h\n" if ($ARGV[1] < 3600);
die "Gateway selection policy must be between 0 and 5!\n" if (($ARGV[2] < 0) || ($ARGV[2] > 5));
# node attributes
my %ncoords = (); # node coordinates
my %nconsumption = (); # consumption
my %nretransmissions = (); # retransmissions per node (per packet)
my %surpressed = ();
my %nreachablegws = (); # reachable gws
my %nptx = (); # transmit power index
my %nresponse = (); # 0/1 (1 = ADR response will be sent)
my %nconfirmed = (); # confirmed transmissions or not
my %nunique = (); # unique transmissions per node (equivalent to FCntUp)
my %nacked = (); # unique acked packets (for confirmed transmissions)
my %ndeliv = (); # unique delivered packets (for non-confirmed transmissions)
my %nperiod = ();
my %ndc = (); # handles node radio duty cycle
my %npkt = (); # packet size per node
my %ntotretr = (); # number of retransmissions per node (total)
# gw attributes
my %gcoords = (); # gw coordinates
my %gunavailability = (); # unavailable gw time due to downlink or locked to another transmission
my %gdc = (); # gw duty cycle (1% uplink channel is used for RX1, 10% downlink channel is used for RX2)
my %gresponses = (); # acks carried out per gw
my %gdest = (); # contains downlink information [node, sf, RX1/2, channel]
# LoRa PHY and LoRaWAN parameters
my @sensis = ([7,-124,-122,-116], [8,-127,-125,-119], [9,-130,-128,-122], [10,-133,-130,-125], [11,-135,-132,-128], [12,-137,-135,-129]); # sensitivities per SF/BW
my @thresholds = ([1,-8,-9,-9,-9,-9], [-11,1,-11,-12,-13,-13], [-15,-13,1,-13,-14,-15], [-19,-18,-17,1,-17,-18], [-22,-22,-21,-20,1,-20], [-25,-25,-25,-24,-23,1]); # capture effect power thresholds per SF[SF] for non-orthogonal transmissions
my $var = 3.57; # variance
my ($dref, $Lpld0, $gamma) = (40, 110, 2.08); # attenuation model parameters
my $max_retr = 8; # max number of retransmissions per packet (default value = 1)
my $bw = 125000; # channel bandwidth
my $cr = 1; # Coding Rate
my $volt = 3.3; # avg voltage
my @Ptx_l = (2, 7, 14); # dBm
my @Ptx_w = (12 * $volt, 30 * $volt, 76 * $volt); # Ptx cons. for 2, 7, 14dBm (mA * V = mW)
my $Prx_w = 46 * $volt;
my $Pidle_w = 30 * $volt; # this is actually the consumption of the microcontroller in idle mode
my @channels = (868100000, 868300000, 868500000, 867100000, 867300000, 867500000, 867700000, 867900000); # TTN channels
my %band = (868100000=>"48", 868300000=>"48", 868500000=>"48", 867100000=>"47", 867300000=>"47", 867500000=>"47", 867700000=>"47", 867900000=>"47"); # band name per channel (all of them with 1% duty cycle)
my $rx2sf = 9; # SF used for RX2 (LoRaWAN default = SF12, TTN uses SF9)
my $rx2ch = 869525000; # channel used for RX2 (LoRaWAN default = 869.525MHz, TTN uses the same)
# packet specific parameters
my @fpl = (222, 222, 115, 51, 51, 51); # max uplink frame payload per SF (bytes)
my $preamble = 8; # in symbols
my $H = 0; # header 0/1
my $hcrc = 0; # HCRC bytes
my $CRC = 1; # 0/1
my $mhdr = 1; # MAC header (bytes)
my $mic = 4; # MIC bytes
my $fhdr = 7; # frame header without fopts
my $adr = 4; # Fopts option for the ADR (4 Bytes)
my $txdc = 1; # Fopts option for the TX duty cycle (1 Byte)
my $fport_u = 1; # 1B for FPort for uplink
my $fport_d = 0; # 0B for FPort for downlink (commands are included in Fopts, acks have no payload)
my $overhead_u = $mhdr+$mic+$fhdr+$fport_u+$hcrc; # LoRa+LoRaWAN uplink overhead
my $overhead_d = $mhdr+$mic+$fhdr+$fport_d+$hcrc; # LoRa+LoRaWAN downlink overhead
my %overlaps = (); # handles special packet overlaps
# simulation parameters
my $confirmed_perc = 1; # percentage of nodes that require confirmed transmissions (1=all)
my $full_collision = 1; # take into account non-orthogonal SF transmissions or not
my $period = 3600/$ARGV[0]; # time period between transmissions
my $sim_time = $ARGV[1]; # given simulation time
my $debug = 0; # enable debug mode
my $sim_end = 0;
my ($terrain, $norm_x, $norm_y) = (0, 0, 0); # terrain side, normalised terrain side
my $start_time = time; # just for statistics
my $successful = 0; # number of delivered packets (not necessarily acked)
my $dropped = 0; # number of dropped packets (for confirmed traffic)
my $dropped_unc = 0; # number of dropped packets (for unconfirmed traffic)
my $total_trans = 0; # number of transm. packets
my $total_retrans = 0; # number of re-transm packets
my $no_rx1 = 0; # no gw was available in RX1
my $no_rx2 = 0; # no gw was available in RX1 or RX2
my $picture = 0; # generate an energy consumption map
my $fixed_packet_rate = 1; # send packets periodically with a fixed rate (=1) or at random (=0)
my $total_down_time = 0; # total downlink time
my $progress_bar = 0; # activate progress bar (slower!)
my $avg_sf = 0;
my @sf_distr = (0, 0, 0, 0, 0, 0);
my $fixed_packet_size = 0; # all nodes have the same packet size defined in @fpl (=1) or a randomly selected (=0)
my $packet_size = 16; # default packet size if fixed_packet_size=1 or avg packet size if fixed_packet_size=0 (Bytes)
my $packet_size_distr = "normal"; # uniform / normal (applicable if fixed_packet_size=0)
my $avg_pkt = 0; # actual average packet size
my %sorted_t = (); # keys = channels, values = list of nodes
my @recents = (); # used in auto_simtime
my $auto_simtime = 0; # 1 = the simulation will automatically stop (useful when sim_time>>10000)
my %sf_retrans = (); # number of retransmissions per SF
# application server
my $policy = $ARGV[2]; # gateway selection policy for downlink traffic
$policy = 2 if ($policy == 0); # default value
my %prev_seq = ();
my %appacked = (); # counts the number of acked packets per node
my %appsuccess = (); # counts the number of packets that received from at least one gw per node
my %nogwavail = (); # counts how many time no gw was available (keys = nodes)
my %powers = (); # contains last 10 received powers per node
my $progress;
if ($progress_bar == 1){
$progress = Term::ProgressBar->new({
count => $sim_time,
ETA => 'linear',
remove => 1
});
$progress->minor(0);
$progress->max_update_rate(1);
}
my $next_update = 0;
read_data(); # read terrain file
# first transmission
my @init_trans = ();
foreach my $n (keys %ncoords){
my $start = random_uniform(1, 0, $period);
my $sf = min_sf($n);
$avg_sf += $sf;
$avg_pkt += $npkt{$n};
my $stop = $start + airtime($sf, $npkt{$n});
print "# $n will transmit from $start to $stop (SF $sf)\n" if ($debug == 1);
$nunique{$n} = 1;
push (@init_trans, [$n, $start, $stop, $channels[rand @channels], $sf, $nunique{$n}]);
$nconsumption{$n} += airtime($sf, $npkt{$n}) * $Ptx_w[$nptx{$n}] + (airtime($sf, $npkt{$n})+1) * $Pidle_w; # +1sec for sensing
$total_trans += 1;
}
# sort transmissions in ascending order
foreach my $t (sort { $a->[1] <=> $b->[1] } @init_trans){
my ($n, $sta, $end, $ch, $sf, $nuni) = @$t;
push (@{$sorted_t{$ch}}, $t);
}
undef @init_trans;
# main loop
while (1){
print "-------------------------------\n" if ($debug == 1);
foreach my $ch (keys %sorted_t){
if (exists $sorted_t{$ch}){
delete $sorted_t{$ch} if (scalar @{$sorted_t{$ch}} == 0);
}
}
# select the channel with earliest transmission among all first transmissions
my $min_ch = (sort {$sorted_t{$a}[0][1] <=> $sorted_t{$b}[0][1]} keys %sorted_t)[0];
my ($sel, $sel_sta, $sel_end, $sel_ch, $sel_sf, $sel_seq) = @{shift(@{$sorted_t{$min_ch}})};
$next_update = $progress->update($sel_end) if ($progress_bar == 1);
if ($sel_sta > $sim_time){
if ($progress_bar == 1){
$next_update = $progress->update($sim_time);
$progress->update($sim_time);
}
last;
}
print "# grabbed $sel, transmission from $sel_sta -> $sel_end\n" if ($debug == 1);
$sim_end = $sel_end;
if ($auto_simtime == 1){
my $nu = (sum values %nunique);
$nu = 1 if ($nu == 0);
if (scalar @recents < 50){
push(@recents, (sum values %nacked)/$nu);
#printf "stddev = %.5f\n", stddev(\@recents);
}else{
if (stddev(\@recents) < 0.00001){
print "### Continuing the simulation will not considerably affect the result! ###\n";
last;
}
shift(@recents);
}
}
if ($sel =~ /^[0-9]/){ # if the packet is an uplink transmission
my $gw_rc = node_col($sel, $sel_sta, $sel_end, $sel_ch, $sel_sf); # check collisions and return a list of gws that received the uplink pkt
my $rwindow = 0;
my $failed = 0;
# keep the last 10 max received powers
my $max_rss = -999;
foreach my $g (@$gw_rc){
$max_rss = @$g[1] if (@$g[1] > $max_rss);
}
push (@{$powers{$sel}}, $max_rss) if ($max_rss > -999);
shift @{$powers{$sel}} if (scalar @{$powers{$sel}} > 10);
# do some ADR tests
my ($new_ptx, $new_index) = (undef, -1);
if (scalar @{$powers{$sel}} == 10){
($new_ptx, $new_index) = adr($sel, $sel_sf);
}
if ((scalar @$gw_rc > 0) && ($nconfirmed{$sel} == 1)){ # if at least one gateway received the pkt -> successful transmission
$successful += 1;
$appsuccess{$sel} += 1 if ($sel_seq > $prev_seq{$sel});
printf "# $sel 's transmission received by %d gateway(s) (channel $sel_ch)\n", scalar @$gw_rc if ($debug == 1);
# now we have to find which gateway (if any) can transmit an ack in RX1 or RX2
# check RX1
my $sel_gw = gs_policy($sel, $sel_sta, $sel_end, $sel_ch, $sel_sf, $gw_rc, 1);
my $extra_bytes = 0;
if (defined $sel_gw){
schedule_downlink($sel_gw, $sel, $sel_sf, $sel_ch, $sel_seq, $sel_end, 1, $extra_bytes, $new_index);
}else{
# check RX2
$no_rx1 += 1;
$sel_gw = gs_policy($sel, $sel_sta, $sel_end, $sel_ch, $sel_sf, $gw_rc, 2);
if (defined $sel_gw){
schedule_downlink($sel_gw, $sel, $sel_sf, $rx2ch, $sel_seq, $sel_end, 2, $new_index);
}else{
$no_rx2 += 1;
print "# no gateway is available\n" if ($debug == 1);
$nogwavail{$sel} += 1;
$failed = 1;
}
}
$prev_seq{$sel} = $sel_seq;
}elsif ((scalar @$gw_rc > 0) && ($nconfirmed{$sel} == 0)){ # successful transmission but no ack is required
$successful += 1;
$ndeliv{$sel} += 1;
printf "# $sel 's transmission received by %d gateway(s) (channel $sel_ch)\n", scalar @$gw_rc if ($debug == 1);
### ADR for unconfirmed transmissions
if (scalar @{$powers{$sel}} == 10){
my ($new_ptx, $new_index) = adr($sel, $sel_sf);
if (defined $new_ptx){
my $sel_gw = gs_policy($sel, $sel_sta, $sel_end, $sel_ch, $sel_sf, $gw_rc, 1);
if (defined $sel_gw){
schedule_downlink($sel_gw, $sel, $sel_sf, $sel_ch, $sel_seq, $sel_end, 1, $new_index);
}else{
$sel_gw = gs_policy($sel, $sel_sta, $sel_end, $sel_ch, $sel_sf, $gw_rc, 2);
if (defined $sel_gw){
schedule_downlink($sel_gw, $sel, $sel_sf, $sel_ch, $sel_seq, $sel_end, 2, $new_index);
}else{
print "# no downlink commands could be sent to $sel\n" if ($debug == 1);
}
}
}
}
###
# remove the examined tuple of gw unavailability
foreach my $gwpr (@$gw_rc){
my ($gw, $pr) = @$gwpr;
my $index = 0;
foreach my $tuple (@{$gunavailability{$gw}}){
my ($sta, $end, $ch, $sf, $m) = @$tuple;
splice @{$gunavailability{$gw}}, $index, 1 if (($end == $sel_end) && ($ch == $sel_ch) && ($sf == $sel_sf) && ($m eq "u"));
last;
}
}
$nconsumption{$sel} += (2-($preamble+4.25)*(2**$sel_sf)/$bw)*$Pidle_w + ($preamble+4.25)*(2**$sel_sf)/$bw * ($Prx_w + $Pidle_w);
$nconsumption{$sel} += ($preamble+4.25)*(2**$rx2sf)/$bw * ($Prx_w + $Pidle_w);
my $new_ch = $channels[rand @channels];
$new_ch = $channels[rand @channels] while ($new_ch == $sel_ch);
$sel_ch = $new_ch;
my $at = airtime($sel_sf, $npkt{$sel});
$sel_sta = $sel_end + $nperiod{$sel} + rand(1);
my $next_allowed = $sel_end + 99*$at; # I need to change this to look at the band
if ($sel_sta < $next_allowed){
print "# warning! transmission will be postponed due to duty cycle restrictions!\n" if ($debug == 1);
$sel_sta = $next_allowed;
}
$sel_end = $sel_sta + $at;
# place the new transmission at the correct position
my $i = 0;
foreach my $el (@{$sorted_t{$sel_ch}}){
my ($n, $sta, $end, $ch_, $sf_, $seq) = @$el;
last if ($sta > $sel_sta);
$i += 1;
}
$nunique{$sel} += 1 if ($sel_sta < $sim_time); # do not count transmissions that exceed the simulation time;
splice(@{$sorted_t{$sel_ch}}, $i, 0, [$sel, $sel_sta, $sel_end, $sel_ch, $sel_sf, $nunique{$sel}]);
$total_trans += 1 if ($sel_sta < $sim_time);
print "# $sel, new transmission at $sel_sta -> $sel_end\n" if ($debug == 1);
$nconsumption{$sel} += $at * $Ptx_w[$nptx{$sel}] + ($at+1) * $Pidle_w;
}else{ # non-successful transmission
$failed = 1;
}
if ($failed == 1){
my $at = 0;
my $new_trans = 0;
if ($nconfirmed{$sel} == 1){
if ($nretransmissions{$sel} < $max_retr){
$nretransmissions{$sel} += 1;
$sf_retrans{$sel_sf} += 1;
my $new_ch = $channels[rand @channels];
$new_ch = $channels[rand @channels] while ($new_ch == $sel_ch);
$sel_ch = $new_ch;
}else{
$dropped += 1;
$ntotretr{$sel} += $nretransmissions{$sel};
$nretransmissions{$sel} = 0;
$new_trans = 1;
print "# $sel 's packet lost!\n" if ($debug == 1);
}
# the node stays on only for the duration of the preamble for both receive windows + in idle mode between RX windows
$nconsumption{$sel} += (2-($preamble+4.25)*(2**$sel_sf)/$bw)*$Pidle_w + ($preamble+4.25)*(2**$sel_sf)/$bw * ($Prx_w + $Pidle_w);
$nconsumption{$sel} += ($preamble+4.25)*(2**$rx2sf)/$bw * ($Prx_w + $Pidle_w);
# plan the next transmission as soon as the duty cycle permits that
$at = airtime($sel_sf, $npkt{$sel});
if ($new_trans == 0){
$sel_sta = $sel_end + 2 + 1 + rand(2);
}else{
$sel_sta = $sel_end + 2 + $nperiod{$sel} + rand(1);
}
$sel_sta = $sel_end + 99*$at + rand(1) if ($sel_sta < ($ndc{$sel}{$sel_ch} + 99*$at));
}else{
$dropped_unc += 1;
$prev_seq{$sel} = $sel_seq;
$new_trans = 1;
print "# $sel 's packet lost!\n" if ($debug == 1);
$at = airtime($sel_sf, $npkt{$sel});
$sel_sta = $sel_end + $nperiod{$sel} + rand(1);
my $next_allowed = $sel_end + 99*$at;
if ($sel_sta < $next_allowed){
print "# warning! transmission will be postponed due to duty cycle restrictions!\n" if ($debug == 1);
$sel_sta = $next_allowed;
}
}
$sel_end = $sel_sta+$at;
$ndc{$sel}{$sel_ch} = $sel_end;
# place the new transmission at the correct position
my $i = 0;
foreach my $el (@{$sorted_t{$sel_ch}}){
my ($n, $sta, $end, $ch_, $sf_, $seq) = @$el;
last if ($sta > $sel_sta);
$i += 1;
}
if (($new_trans == 1) && ($sel_sta < $sim_time)){ # do not count transmissions that exceed the simulation time
$nunique{$sel} += 1;
}
splice(@{$sorted_t{$sel_ch}}, $i, 0, [$sel, $sel_sta, $sel_end, $sel_ch, $sel_sf, $nunique{$sel}]);
$total_trans += 1 ;
$total_retrans += 1 if ($nconfirmed{$sel} == 1);
print "# $sel, new transmission at $sel_sta -> $sel_end\n" if ($debug == 1);
$nconsumption{$sel} += $at * $Ptx_w[$nptx{$sel}] + ($at+1) * $Pidle_w;
}
foreach my $g (keys %gcoords){
$surpressed{$sel}{$g} = 0;
}
}else{ # if the packet is a gw transmission
$sel =~ s/[0-9].*//; # keep only the letter(s)
# remove the unnecessary tuples from gw unavailability
my @indices = ();
my $index = 0;
foreach my $tuple (@{$gunavailability{$sel}}){
my ($sta, $end, $ch, $sf, $m) = @$tuple;
push (@indices, $index) if ($end < $sel_sta);
$index += 1;
}
for (sort {$b<=>$a} @indices){
splice @{$gunavailability{$sel}}, $_, 1;
}
# look for the examined transmission in gdest, get some info, and then remove it
my $failed = 0;
$index = 0;
# ($sel, $sel_sta, $sel_end, $sel_ch, $sel_sf, $sel_seq) information we already have
# sel_sf = SF of the downlink, sf = SF of the corresponding uplink in gdest
my ($dest, $st, $sf, $rwindow, $ch, $pow); # we also need dest, rwindow, and pow (the others should be the same)
foreach my $tup (@{$gdest{$sel}}){
my ($dest_, $st_, $sf_, $rwindow_, $ch_, $p_) = @$tup;
if (($st_ == $sel_sta) && ($ch_ == $sel_ch)){
($dest, $st, $sf, $rwindow, $ch, $pow) = ($dest_, $st_, $sf_, $rwindow_, $ch_, $p_);
last;
}
$index += 1;
}
splice @{$gdest{$sel}}, $index, 1;
# check if the transmission can reach the node
my $G = random_normal(1, 0, 1);
my $d = distance($gcoords{$sel}[0], $ncoords{$dest}[0], $gcoords{$sel}[1], $ncoords{$dest}[1]);
my $prx = 14 - ($Lpld0 + 10*$gamma * log10($d/$dref) + $G*$var);
if ($prx < $sensis[$sel_sf-7][bwconv($bw)]){
print "# ack didn't reach node $dest\n" if ($debug == 1);
$failed = 1;
}
# check if transmission time overlaps with other transmissions
foreach my $tr (@{$sorted_t{$ch}}){
my ($n, $sta, $end, $ch_, $sf_, $seq) = @$tr;
last if ($sta > $sel_end);
$n =~ s/[0-9].*// if ($n =~ /^[A-Z]/);
next if (($n eq $sel) || ($end < $sel_sta) || ($ch_ != $ch)); # skip non-overlapping transmissions or different channels
if ( (($sel_sta >= $sta) && ($sel_sta <= $end)) || (($sel_end <= $end) && ($sel_end >= $sta)) || (($sel_sta == $sta) && ($sel_end == $end)) ){
push(@{$overlaps{$sel}}, [$n, $G, $sf_]); # put in here all overlapping transmissions
push(@{$overlaps{$n}}, [$sel, $G, $sel_sf]); # check future possible collisions with those transmissions
}
}
my %examined = ();
foreach my $ng (@{$overlaps{$sel}}){
my ($n, $G_, $sf_) = @$ng;
next if (exists $examined{$n});
$examined{$n} = 1;
my $overlap = 1;
# SF
if ($sf_ == $sel_sf){
$overlap += 2;
}
# power
my $d_ = 0;
my $p = 0;
if ($n =~ /^[0-9]/){
$d_ = distance($ncoords{$dest}[0], $ncoords{$n}[0], $ncoords{$dest}[1], $ncoords{$n}[1]);
$p = $Ptx_l[$nptx{$n}];
}else{
$d_ = distance($ncoords{$dest}[0], $gcoords{$n}[0], $ncoords{$dest}[1], $gcoords{$n}[1]);
$p = 14;
}
my $prx_ = $p - ($Lpld0 + 10*$gamma * log10($d_/$dref) + $G_*$var);
if ($overlap == 3){
if ((abs($prx - $prx_) <= $thresholds[$sel_sf-7][$sf_-7]) ){ # both collide
$failed = 1;
print "# ack collided together with $n at node $sel\n" if ($debug == 1);
}
if (($prx_ - $prx) > $thresholds[$sel_sf-7][$sf_-7]){ # n suppressed sel
$failed = 1;
print "# ack surpressed by $n at node $dest\n" if ($debug == 1);
}
if (($prx - $prx_) > $thresholds[$sf_-7][$sel_sf-7]){ # sel suppressed n
print "# $n surpressed by $sel at node $dest\n" if ($debug == 1);
}
}
if (($overlap == 1) && ($full_collision == 1)){ # non-orthogonality
if (($prx - $prx_) > $thresholds[$sel_sf-7][$sf_-7]){
if (($prx_ - $prx) <= $thresholds[$sf_-7][$sel_sf-7]){
print "# $n surpressed by $sel at node $dest\n" if ($debug == 1);
}
}else{
if (($prx_ - $prx) > $thresholds[$sf_-7][$sel_sf-7]){
$failed = 1;
print "# ack surpressed by $n at node $dest\n" if ($debug == 1);
}else{
$failed = 1;
print "# ack collided together with $n at node $dest\n" if ($debug == 1);
}
}
}
}
my $new_trans = 0;
if ($failed == 0){
if ($nconfirmed{$dest} == 1){
print "# ack successfully received, $dest 's transmission has been acked\n" if ($debug == 1);
$ntotretr{$dest} += $nretransmissions{$dest};
$nretransmissions{$dest} = 0;
$nacked{$dest} += 1;
$new_trans = 1;
}
if ($rwindow == 2){ # also count the RX1 window
$nconsumption{$dest} += (2-($preamble+4.25)*(2**$sf)/$bw)*$Pidle_w + ($preamble+4.25)*(2**$sf)/$bw * ($Prx_w + $Pidle_w);
}
my $extra_bytes = 0; # if an ADR request is included in the downlink packet
if ($pow != -1){
$nptx{$dest} = $pow;
$extra_bytes = $adr;
$nresponse{$dest} = 1;
print "# transmit power of $dest is set to $Ptx_l[$pow]\n" if ($debug == 1);
}
$nconsumption{$dest} += airtime($sel_sf, $overhead_d+$extra_bytes) * ($Prx_w + $Pidle_w);
}else{ # ack was not received
if ($nconfirmed{$dest} == 1){
if ($nretransmissions{$dest} < $max_retr){
$nretransmissions{$dest} += 1;
$sf_retrans{$sf} += 1;
}else{
$dropped += 1;
$ntotretr{$dest} += $nretransmissions{$dest};
$nretransmissions{$dest} = 0;
$new_trans = 1;
print "# $dest 's packet lost (no ack received)!\n" if ($debug == 1);
}
}
$nconsumption{$dest} += (2-($preamble+4.25)*(2**$sf)/$bw)*$Pidle_w + ($preamble+4.25)*(2**$sf)/$bw * ($Prx_w + $Pidle_w);
$nconsumption{$dest} += ($preamble+4.25)*(2**$rx2sf)/$bw * ($Prx_w + $Pidle_w);
}
@{$overlaps{$sel}} = ();
if ($nconfirmed{$dest} == 1){
# plan next transmission
$ch = $channels[rand @channels];
my $extra_bytes = 0;
if ($nresponse{$dest} == 1){
$extra_bytes = $adr;
$nresponse{$dest} = 0;
}
my $at = airtime($sf, $npkt{$dest}+$extra_bytes);
my $new_start = $sel_sta - $rwindow + $nperiod{$dest} + rand(1);
$new_start = $sel_sta - $rwindow + 2 + 1 + rand(2) if ($failed == 1 && $new_trans == 0);
my $next_allowed = $ndc{$dest}{$ch} + 99*$at;
if ($new_start < $next_allowed){
print "# warning! transmission will be postponed due to duty cycle restrictions!\n" if ($debug == 1);
$new_start = $next_allowed;
}
if (($new_trans == 1) && ($new_start < $sim_time)){ # do not count transmissions that exceed the simulation time
$nunique{$dest} += 1;
}
my $new_end = $new_start + $at;
$ndc{$dest}{$ch} = $new_end;
my $i = 0;
foreach my $el (@{$sorted_t{$ch}}){
my ($n, $sta, $end, $ch_, $sf_, $seq) = @$el;
last if ($sta > $new_start);
$i += 1;
}
splice(@{$sorted_t{$ch}}, $i, 0, [$dest, $new_start, $new_end, $ch, $sf, $nunique{$dest}]);
$total_trans += 1 if ($new_start < $sim_time); # do not count transmissions that exceed the simulation time
$total_retrans += 1 if (($failed == 1) && ($new_start < $sim_time));
print "# $dest, new transmission at $new_start -> $new_end\n" if ($debug == 1);
$nconsumption{$dest} += $at * $Ptx_w[$nptx{$dest}] + ($at+1) * $Pidle_w if ($new_start < $sim_time);
}
}
}
# print "---------------------\n";
my $avg_cons = (sum values %nconsumption)/(scalar keys %nconsumption);
my $min_cons = min values %nconsumption;
my $max_cons = max values %nconsumption;
my $finish_time = time;
printf "Simulation time = %.3f secs\n", $sim_end;
printf "Avg node consumption = %.5f J\n", $avg_cons/1000;
printf "Min node consumption = %.5f J\n", $min_cons/1000;
printf "Max node consumption = %.5f J\n", $max_cons/1000;
print "Total number of transmissions = $total_trans\n";
print "Total number of re-transmissions = $total_retrans\n" if ($confirmed_perc > 0);
printf "Total number of unique transmissions = %d\n", (sum values %nunique);
printf "Stdv of unique transmissions = %.2f\n", stddev(values %nunique);
print "Total packets delivered = $successful\n";
printf "Total packets acknowledged = %d\n", (sum values %nacked);
print "Total confirmed packets dropped = $dropped\n";
print "Total unconfirmed packets dropped = $dropped_unc\n";
printf "Packet Delivery Ratio = %.5f\n", ((sum values %nacked)+(sum values %ndeliv))/(sum values %nunique); # unique packets delivered / unique packets transmitted
printf "Packet Reception Ratio = %.5f\n", $successful/$total_trans; # Global PRR
my @fairs = ();
foreach my $n (keys %ncoords){
if ($nconfirmed{$n} == 0){
push(@fairs, $ndeliv{$n}/$nunique{$n});
}
}
printf "Uplink fairness = %.3f\n", stddev(\@fairs) if (scalar @fairs > 0); # for unconfirmed traffic
print "No GW available in RX1 = $no_rx1 times\n";
print "No GW available in RX1 or RX2 = $no_rx2 times\n";
print "Total downlink time = $total_down_time sec\n";
printf "Script execution time = %.4f secs\n", $finish_time - $start_time;
print "-----\n";
if (scalar keys %nconfirmed > 0){
foreach my $g (sort keys %gcoords){
print "GW $g sent out $gresponses{$g} acks and commands\n";
}
@fairs = ();
my $avgretr = 0;
foreach my $n (keys %ncoords){
next if ($nconfirmed{$n} == 0);
$appsuccess{$n} = 1 if ($appsuccess{$n} == 0);
push(@fairs, $appacked{$n}/$appsuccess{$n});
$avgretr += $ntotretr{$n}/$nunique{$n};
}
printf "Downlink fairness = %.3f\n", stddev(\@fairs);
printf "Avg number of retransmissions = %.3f\n", $avgretr/(scalar keys %ntotretr);
printf "Stdev of retransmissions = %.3f\n", (stddev values %ntotretr);
print "-----\n";
}
for (my $sf=7; $sf<=12; $sf+=1){
printf "# of nodes with SF%d: %d, Avg retransmissions: %.2f\n", $sf, $sf_distr[$sf-7], $sf_retrans{$sf}/$sf_distr[$sf-7] if ($sf_distr[$sf-7] > 0);
}
printf "Avg SF = %.3f\n", $avg_sf/(scalar keys %ncoords);
printf "Avg packet size = %.3f bytes\n", $avg_pkt/(scalar keys %ncoords);
generate_picture() if ($picture == 1);
sub schedule_downlink{
my ($sel_gw, $sel, $sel_sf, $sel_ch, $sel_seq, $sel_end, $rwindow, $new_index) = @_;
my $bnd = "54"; # band: 54 for 869525000 RX2
$bnd = $band{$sel_ch} if ($rwindow == 1);
my $extra_bytes = 0;
if ($new_index != -1){
print "# it will be suggested that $sel changes tx power to $Ptx_l[$new_index]\n" if ($debug == 1);
$extra_bytes = $adr;
}
my $airt = airtime($sel_sf, $overhead_d+$extra_bytes);
my ($ack_sta, $ack_end) = ($sel_end+$rwindow, $sel_end+$rwindow+$airt);
$total_down_time += $airt;
print "# gw $sel_gw will transmit an ack (or commands) to $sel (RX$rwindow) (channel $sel_ch)\n" if ($debug == 1);
$gresponses{$sel_gw} += 1;
push (@{$gunavailability{$sel_gw}}, [$ack_sta, $ack_end, $sel_ch, $sel_sf, "d"]);
my $dc = 99;
$dc = 9 if ($rwindow == 2);
$gdc{$sel_gw}{$bnd} = $ack_end+$airt*$dc;
my $new_name = $sel_gw.$gresponses{$sel_gw}; # e.g. A1
# place new transmission at the correct position
my $i = 0;
foreach my $el (@{$sorted_t{$sel_ch}}){
my ($n, $sta, $end, $ch, $sf, $seq) = @$el;
last if ($sta > $ack_sta);
$i += 1;
}
$appacked{$sel} += 1 if (($sel_seq > $prev_seq{$sel}) && ($nconfirmed{$sel} == 1));
splice(@{$sorted_t{$sel_ch}}, $i, 0, [$new_name, $ack_sta, $ack_end, $sel_ch, $sel_sf, $appacked{$sel}]);
push (@{$gdest{$sel_gw}}, [$sel, $sel_end+$rwindow, $sel_sf, $rwindow, $sel_ch, $new_index]);
}
sub gs_policy{ # gateway selection policy
my ($sel, $sel_sta, $sel_end, $sel_ch, $sel_sf, $gw_rc, $win) = @_;
my $sel_gw = undef;
my $bnd = $band{$sel_ch};
if ($win == 2){
$bnd = "54";
$sel_ch = $rx2ch;
if ($sel_sf < $rx2sf){
@$gw_rc = @{$nreachablegws{$sel}};
}
$sel_sf = $rx2sf;
}
my ($ack_sta, $ack_end) = ($sel_end+$win, $sel_end+$win+airtime($sel_sf, $overhead_d));
my ($min_resp, $sel_p, $min_dc) = (1, -9999999999999, 9999999999999);
my @avail = ();
foreach my $g (@$gw_rc){
my ($gw, $p) = @$g;
my $is_avail = 1;
if ($gdc{$gw}{$bnd} > ($sel_end+$win)){
next;
}
foreach my $gu (@{$gunavailability{$gw}}){
my ($sta, $end, $ch, $sf, $m) = @$gu;
if ( (($ack_sta >= $sta) && ($ack_sta <= $end)) || (($ack_end <= $end) && ($ack_end >= $sta)) ){
$is_avail = 0;
last;
}
}
next if ($is_avail == 0);
push (@avail, $g);
}
return (undef, undef) if (scalar @avail == 0);
if ($policy == 4){ # URCB
my $avgretr = (sum values %nogwavail)/(scalar keys %ncoords);
if ( ($nogwavail{$sel} < $avgretr) && ((scalar @avail)/(scalar @$gw_rc) < 2/3) ){
return (undef, undef);
}
}
if ($policy == 5){ # FBS
my $avgfair = 0;
foreach my $n (keys %ncoords){
next if ($appsuccess{$n} == 0);
$avgfair += $appacked{$n}/$appsuccess{$n};
}
$avgfair /= (scalar keys %ncoords);
if ( ($appacked{$sel}/$appsuccess{$sel} >= $avgfair) && ((scalar @avail)/(scalar @$gw_rc) < 2/3) && ($avgfair != 0) ){
return (undef, undef);
}
}
foreach my $g (@avail){
my ($gw, $p) = @$g;
if ($policy == 1){ # FCFS
my $resp = rand(2)/10;
if ($resp < $min_resp){
$min_resp = $resp;
$sel_gw = $gw;
}
}elsif (($policy == 2) || ($policy == 4) || ($policy == 5)){ # RSSI
if ($p > $sel_p){
$sel_gw = $gw;
$sel_p = $p;
}
}elsif ($policy == 3){ # less busy gw
if ($gdc{$gw}{$bnd} < $min_dc){
$min_dc = $gdc{$gw}{$bnd};
$sel_gw = $gw;
}
}
}
return $sel_gw;
}
sub adr{ # ADR: the SF is already adjusted in min_sf; here only the transmit power is adjusted
my ($sel, $sel_sf) = @_;
my $avg_p = (sum @{$powers{$sel}})/10;
my $gap = $avg_p - $sensis[$sel_sf-7][bwconv($bw)];
my $new_ptx = undef;
my $new_index = -1;
foreach my $p (sort {$a<=>$b} @Ptx_l){
$new_index += 1;
next if ($p >= $Ptx_l[$nptx{$sel}]); # we can only decrease power at the moment
if ($gap-$Ptx_l[$nptx{$sel}]+$p >= 12){
$new_ptx = $p;
last;
}
}
return ($new_ptx, $new_index);
}
sub node_col{ # handle node collisions
my ($sel, $sel_sta, $sel_end, $sel_ch, $sel_sf) = @_;
# check for collisions with other transmissions (time, SF, power) per gw
my @gw_rc = ();
foreach my $gw (keys %gcoords){
next if ($surpressed{$sel}{$gw} == 1);
my $d = distance($gcoords{$gw}[0], $ncoords{$sel}[0], $gcoords{$gw}[1], $ncoords{$sel}[1]);
my $G = random_normal(1, 0, 1);
my $prx = $Ptx_l[$nptx{$sel}] - ($Lpld0 + 10*$gamma * log10($d/$dref) + $G*$var);
if ($prx < $sensis[$sel_sf-7][bwconv($bw)]){
$surpressed{$sel}{$gw} = 1;
print "# packet didn't reach gw $gw\n" if ($debug == 1);
next;
}
# check if the gw is available for uplink
my $is_available = 1;
foreach my $gu (@{$gunavailability{$gw}}){
my ($sta, $end, $ch, $sf, $m) = @$gu;
if ( (($sel_sta >= $sta) && ($sel_sta <= $end)) || (($sel_end <= $end) && ($sel_end >= $sta)) || (($sel_sta == $sta) && ($sel_end == $end))){
# the gw has either locked to another transmission with the same ch/sf OR is being used for downlink
if ( ($m eq "d") || (($m eq "u") && ($sel_ch == $ch) && ($sel_sf == $sf)) ){
$is_available = 0;
last;
}
}
}
if ($is_available == 0){
$surpressed{$sel}{$gw} = 1;
print "# gw not available for uplink (channel $sel_ch, SF $sel_sf)\n" if ($debug == 1);
next;
}
foreach my $tr (@{$sorted_t{$sel_ch}}){
my ($n, $sta, $end, $ch, $sf, $seq) = @$tr;
last if ($sta > $sel_end);
if ($n =~ /^[0-9]/){ # node transmission
next if (($n == $sel) || ($sta > $sel_end) || ($end < $sel_sta) || ($ch != $sel_ch));
my $overlap = 0;
# time overlap
if ( (($sel_sta >= $sta) && ($sel_sta <= $end)) || (($sel_end <= $end) && ($sel_end >= $sta)) || (($sel_sta == $sta) && ($sel_end == $end)) ){
$overlap += 1;
}
# SF
if ($sf == $sel_sf){
$overlap += 2;
}
# power
my $d_ = distance($gcoords{$gw}[0], $ncoords{$n}[0], $gcoords{$gw}[1], $ncoords{$n}[1]);
my $prx_ = $Ptx_l[$nptx{$n}] - ($Lpld0 + 10*$gamma * log10($d_/$dref) + rand(1)*$var);
if ($overlap == 3){
if ((abs($prx - $prx_) <= $thresholds[$sel_sf-7][$sf-7]) ){ # both collide
$surpressed{$sel}{$gw} = 1;
$surpressed{$n}{$gw} = 1;
print "# $sel collided together with $n at gateway $gw\n" if ($debug == 1);
}
if (($prx_ - $prx) > $thresholds[$sel_sf-7][$sf-7]){ # n suppressed sel
$surpressed{$sel}{$gw} = 1;
print "# $sel surpressed by $n at gateway $gw\n" if ($debug == 1);
}
if (($prx - $prx_) > $thresholds[$sf-7][$sel_sf-7]){ # sel suppressed n
$surpressed{$n}{$gw} = 1;
print "# $n surpressed by $sel at gateway $gw\n" if ($debug == 1);
}
}
if (($overlap == 1) && ($full_collision == 1)){ # non-orthogonality
if (($prx - $prx_) > $thresholds[$sel_sf-7][$sf-7]){
if (($prx_ - $prx) <= $thresholds[$sf-7][$sel_sf-7]){
$surpressed{$n}{$gw} = 1;
print "# $n surpressed by $sel\n" if ($debug == 1);
}
}else{
if (($prx_ - $prx) > $thresholds[$sf-7][$sel_sf-7]){
$surpressed{$sel}{$gw} = 1;
print "# $sel surpressed by $n\n" if ($debug == 1);
}else{
$surpressed{$sel}{$gw} = 1;
$surpressed{$n}{$gw} = 1;
print "# $sel collided together with $n\n" if ($debug == 1);
}
}
}
}else{ # n is a gw in this case
my $nn = $n;
$n =~ s/[0-9].*//; # keep only the letter(s)
next if (($nn eq $gw) || ($sta > $sel_end) || ($end < $sel_sta) || ($ch != $sel_ch));
# time overlap
if ( (($sel_sta >= $sta) && ($sel_sta <= $end)) || (($sel_end <= $end) && ($sel_end >= $sta)) || (($sel_sta == $sta) && ($sel_end == $end)) ){
my $already_there = 0;
my $G_ = random_normal(1, 0, 1);
foreach my $ng (@{$overlaps{$sel}}){
my ($n_, $G_, $sf_) = @$ng;
if ($n_ eq $n){
$already_there = 1;
}
}
if ($already_there == 0){
push(@{$overlaps{$sel}}, [$n, $G_, $sf]); # put in here all overlapping transmissions
}
push(@{$overlaps{$nn}}, [$sel, $G, $sel_sf]); # check future possible collisions with those transmissions
}
foreach my $ng (@{$overlaps{$sel}}){
my ($n, $G_, $sf_) = @$ng;
my $overlap = 1;
# SF
if ($sf_ == $sel_sf){
$overlap += 2;
}
# power
my $d_ = distance($gcoords{$gw}[0], $gcoords{$n}[0], $gcoords{$gw}[1], $gcoords{$n}[1]);
my $prx_ = 14 - ($Lpld0 + 10*$gamma * log10($d_/$dref) + $G_*$var);
if ($overlap == 3){
if ((abs($prx - $prx_) <= $thresholds[$sel_sf-7][$sf_-7]) ){ # both collide
$surpressed{$sel}{$gw} = 1;
print "# $sel collided together with $n at gateway $gw\n" if ($debug == 1);
}
if (($prx_ - $prx) > $thresholds[$sel_sf-7][$sf_-7]){ # n suppressed sel
$surpressed{$sel}{$gw} = 1;
print "# $sel surpressed by $n at gateway $gw\n" if ($debug == 1);
}
if (($prx - $prx_) > $thresholds[$sf_-7][$sel_sf-7]){ # sel suppressed n
print "# $n surpressed by $sel at gateway $gw\n" if ($debug == 1);
}
}
if (($overlap == 1) && ($full_collision == 1)){ # non-orthogonality
if (($prx - $prx_) > $thresholds[$sel_sf-7][$sf_-7]){
if (($prx_ - $prx) <= $thresholds[$sf_-7][$sel_sf-7]){
print "# $n surpressed by $sel\n" if ($debug == 1);
}
}else{
if (($prx_ - $prx) > $thresholds[$sf_-7][$sel_sf-7]){
$surpressed{$sel}{$gw} = 1;
print "# $sel surpressed by $n\n" if ($debug == 1);
}else{
$surpressed{$sel}{$gw} = 1;
print "# $sel collided together with $n\n" if ($debug == 1);
}
}
}
}
}
}
if ($surpressed{$sel}{$gw} == 0){
push (@gw_rc, [$gw, $prx]);
# set the gw unavailable (exclude preamble) and lock to the specific Ch/SF
my $Tsym = (2**$sel_sf)/$bw;
my $Tpream = ($preamble + 4.25)*$Tsym;
push(@{$gunavailability{$gw}}, [$sel_sta+$Tpream, $sel_end, $sel_ch, $sel_sf, "u"]);
}
}
@{$overlaps{$sel}} = ();
return (\@gw_rc);
}
sub min_sf{
my $n = shift;
my $G = 0; # assume that variance is 0
my $Xs = $var*$G;
my $sf = 13;
my $bwi = bwconv($bw);
foreach my $gw (keys %gcoords){
my $gf = 13;
my $d0 = distance($gcoords{$gw}[0], $ncoords{$n}[0], $gcoords{$gw}[1], $ncoords{$n}[1]);
for (my $f=7; $f<=12; $f+=1){
my $S = $sensis[$f-7][$bwi];
my $Prx = $Ptx_l[$nptx{$n}] - ($Lpld0 + 10*$gamma * log10($d0/$dref) + $Xs);
if (($Prx - 10) > $S){ # 10dBm tolerance
$gf = $f;
$f = 13;
last;
}
}
$sf = $gf if ($gf < $sf);
}
# check which gateways can be reached with rx2sf
foreach my $gw (keys %gcoords){
my $d0 = distance($gcoords{$gw}[0], $ncoords{$n}[0], $gcoords{$gw}[1], $ncoords{$n}[1]);
my $S = $sensis[$rx2sf-7][$bwi];
my $Prx = $Ptx_l[$nptx{$n}] - ($Lpld0 + 10*$gamma * log10($d0/$dref) + $Xs);
if (($Prx - 10) > $S){ # 10dBm tolerance
push(@{$nreachablegws{$n}}, [$gw, $Prx]);
}
}
if ($sf == 13){
print "node $n unreachable!\n";
print "terrain too large?\n";
exit;
}
if ($fixed_packet_size == 0){
if ($packet_size_distr eq "uniform"){
$npkt{$n} = int(rand($fpl[$sf-7]));
}elsif ($packet_size_distr eq "normal"){
$npkt{$n} = int(random_normal(1, $packet_size, 10));
}
}else{
$npkt{$n} = $packet_size;
}
$npkt{$n} = $fpl[$sf-7] if (($npkt{$n} > $fpl[$sf-7]) || ($npkt{$n} < 1));
$npkt{$n} += $overhead_u;
print "# $n can reach a gw with SF$sf\n" if ($debug == 1);
$sf_distr[$sf-7] += 1;
return $sf;
}
# a modified version of LoRaSim (https://www.lancaster.ac.uk/scc/sites/lora/lorasim.html)
sub airtime{
my $sf = shift;
my $DE = 0; # low data rate optimization enabled (=1) or not (=0)
my $payload = shift;
if (($bw == 125000) && (($sf == 11) || ($sf == 12))){
# low data rate optimization mandated for BW125 with SF11 and SF12
$DE = 1;
}
my $Tsym = (2**$sf)/$bw;
my $Tpream = ($preamble + 4.25)*$Tsym;
my $payloadSymbNB = 8 + max( ceil((8.0*$payload-4.0*$sf+28+16*$CRC-20*$H)/(4.0*($sf-2*$DE)))*($cr+4), 0 );
my $Tpayload = $payloadSymbNB * $Tsym;
return ($Tpream + $Tpayload);
}
sub bwconv{
my $bwi = 0;
if ($bw == 125000){
$bwi = 1;
}elsif ($bw == 250000){
$bwi = 2;
}elsif ($bw == 500000){
$bwi = 3;
}
return $bwi;
}
sub read_data{
my $terrain_file = $ARGV[3];
open(FH, "<$terrain_file") or die "Error: could not open terrain file $terrain_file\n";
my @nodes = ();
my @gateways = ();
while(<FH>){
chomp;
if (/^# stats: (.*)/){
my $stats_line = $1;
if ($stats_line =~ /terrain=([0-9]+\.[0-9]+)m\^2/){
$terrain = $1;
}
$norm_x = sqrt($terrain);
$norm_y = sqrt($terrain);
} elsif (/^# node coords: (.*)/){
my $sensor_coord = $1;
my @coords = split(/\] /, $sensor_coord);
@nodes = map { /([0-9]+) \[([0-9]+\.[0-9]+) ([0-9]+\.[0-9]+)/; [$1, $2, $3]; } @coords;
} elsif (/^# gateway coords: (.*)/){
my $gw_coord = $1;
my @coords = split(/\] /, $gw_coord);
@gateways = map { /([A-Z]+) \[([0-9]+\.[0-9]+) ([0-9]+\.[0-9]+)/; [$1, $2, $3]; } @coords;
}
}
close(FH);
my $conf_num = int($confirmed_perc * (scalar @nodes));
foreach my $node (@nodes){
my ($n, $x, $y) = @$node;
$ncoords{$n} = [$x, $y];
@{$overlaps{$n}} = ();
$nptx{$n} = scalar @Ptx_l - 1; # start with the highest Ptx
$nresponse{$n} = 0;
$nretransmissions{$n} = 0;
if ($conf_num > 0){
$nconfirmed{$n} = 1;
$conf_num -= 1;
$ntotretr{$n} = 0;