Sink Node Does Not Receive Any Packet

Hello,

I am trying to send packets from 4 underwater sensor nodes (node 1-4) to the sink (node 0) using the SFAMA MAC protocol. I have tried to change many parameters, but still have the same problem. All nodes able to send packets, but non of these packets have been received by the sink. Can anyone help why the sink node does not receive any packet?

SFAMA script:
Code:set opt(chan) Channel/UnderwaterChannel
set opt(prop) Propagation/UnderwaterPropagation
set opt(netif) Phy/UnderwaterPhy
set opt(mac) Mac/UnderwaterMac/SFAMA
set opt(ifq) Queue/DropTail/PriQueue
set opt(ll) LL
set opt(energy) EnergyModel
set opt(txpower) 0.6
set opt(rxpower) 0.3
set opt(initialenergy) 10000
set opt(idlepower) 0.01
set opt(ant) Antenna/OmniAntenna ;#we don't use it in underwater
set opt(filters) GradientFilter ;# options can be one or more of
;# TPP/OPP/Gear/Rmst/SourceRoute/Log/TagFilter

# the following parameters are set fot protocols
set opt(bit_rate) 1.0e4
set opt(encoding_efficiency) 1
set opt(ND_window) 1
set opt(ACKND_window) 1
set opt(PhaseOne_window) 3
set opt(PhaseTwo_window) 1
set opt(PhaseTwo_interval) 0.5
set opt(IntervalPhase2Phase3) 1
set opt(duration) 0.1
set opt(PhyOverhead) 8
set opt(large_packet_size) 480 ;# 60 bytes
set opt(short_packet_size) 40 ;# 5 bytes
set opt(PhaseOne_cycle) 4 ;
set opt(PhaseTwo_cycle) 2 ;
set opt(PeriodInterval) 1
set opt(transmission_time_error) 0.0001;

set opt(dz) 10
set opt(ifqlen) 50 ;# max packet in ifq
set opt(nn) 5 ;# number of nodes in each layer
set opt(layers) 1
set opt(x) 100 ;# X dimension of the topography
set opt(y) 100 ;# Y dimension of the topography
set opt(z) [expr ($opt(layers)-1)*$opt(dz)]
set opt(seed) 348.88
set opt(stop) 1000 ;# simulation time
set opt(prestop) 20 ;# time to prepare to stop
set opt(tr) "rmac_to_sfama.tr" ;# trace file
set opt(nam) "rmac_to_sfama.nam" ;# nam file
set opt(datafile) "rmac_to_sfama.data" ;# data file
set opt(adhocRouting) Vectorbasedforward
set opt(width) 100
set opt(adj) 10
set opt(interval) 0.05
#set opt(traf) "diffusion-traf.tcl" ;# traffic file

# ==================================================================

LL set mindelay_ 50us
LL set delay_ 25us
LL set bandwidth_ 0 ;# not used

Queue/DropTail/PriQueue set Prefer_Routing_Protocols 1

# unity gain, omni-directional antennas
# set up the antennas to be centered in the node and 1.5 meters above it
Antenna/OmniAntenna set X_ 0
Antenna/OmniAntenna set Y_ 0
Antenna/OmniAntenna set Z_ 1.5
Antenna/OmniAntenna set Z_ 0.05
Antenna/OmniAntenna set Gt_ 1.0
Antenna/OmniAntenna set Gr_ 1.0

Mac/UnderwaterMac set bit_rate_ $opt(bit_rate)
Mac/UnderwaterMac set encoding_efficiency_ $opt(encoding_efficiency)

Mac/UnderwaterMac/SFAMA set guard_time_ 0.001
Mac/UnderwaterMac/SFAMA set max_backoff_slots_ 4
Mac/UnderwaterMac/SFAMA set max_burst_ 1
Mac/UnderwaterMac/SFAMA set dataSize 500;
Mac/UnderwaterMac/SFAMA set controlSize 20;
Mac/UnderwaterMac/SFAMA set maxPropDelay 1;

# Initialize the SharedMedia interface with parameters to make
# it work like the 914MHz Lucent WaveLAN DSSS radio interface
Phy/UnderwaterPhy set CPThresh_ 100 ;#10.0
Phy/UnderwaterPhy set CSThresh_ 0 ;#1.559e-11
Phy/UnderwaterPhy set RXThresh_ 0 ;#3.652e-10
#Phy/UnderwaterPhy set Rb_ 2*1e6
Phy/UnderwaterPhy set Pt_ 0.2818
Phy/UnderwaterPhy set freq_ 25 ;#frequency range in khz
Phy/UnderwaterPhy set K_ 2.0 ;#spherical spreading

# ==================================================================
# Main Program
# =================================================================
#
# Initialize Global Variables
#
#set sink_ 1

remove-all-packet-headers
#remove-packet-header AODV ARP TORA IMEP TFRC
add-packet-header IP Mac LL ARP UWVB RMAC

set ns_ [new Simulator]
set topo [new Topography]

$topo load_cubicgrid $opt(x) $opt(y) $opt(z)
#$ns_ use-newtrace
set tracefd [open $opt(tr) w]
$ns_ trace-all $tracefd

set nf [open $opt(nam) w]
$ns_ namtrace-all-wireless $nf $opt(x) $opt(y)

set start_time 1
#set start_time [expr $phase1_time+$phase2_time+$opt(IntervalPhase2Phase3)]

puts "the start time is $start_time"

set total_number [expr $opt(nn)-1]
set god_ [create-god $opt(nn)]
set chan_1_ [new $opt(chan)]

global defaultRNG
$defaultRNG seed $opt(seed)

$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) \
#-channelType $opt(chan) \
-agentTrace OFF \
-routerTrace OFF \
-macTrace ON\
-topoInstance $topo\
-energyModel $opt(energy)\
-txpower $opt(txpower)\
-rxpower $opt(rxpower)\
-initialEnergy $opt(initialenergy)\
-idlePower $opt(idlepower)\
-channel $chan_1_

set node_(0) [$ns_ node 0]
$node_(0) set sinkStatus_ 1
$node_(0) set passive 1
$god_ new_node $node_(0)
$node_(0) set X_ 0
$node_(0) set Y_ 0
$node_(0) set Z_ 0
$node_(0) set passive 1
set a_(0) [new Agent/UWSink]
$ns_ attach-agent $node_(0) $a_(0)
$a_(0) attach-vectorbasedforward $opt(width)
$a_(0) cmd set-range 100
$a_(0) cmd set-target-x -20
$a_(0) cmd set-target-y -10
$a_(0) cmd set-target-z -20

set node_(1) [$ns_ node 1]
$node_(1) set sinkStatus_ 1
$god_ new_node $node_(1)
$node_(1) set X_ 0
$node_(1) set Y_ -15
$node_(1) set Z_ 0
$node_(1) set-cx 0
$node_(1) set-cy -15
$node_(1) set-cz 0
$node_(1) set_next_hop 0 ;# target is node 0
#$node_(1) set passive 1
set a_(1) [new Agent/UWSink]
$ns_ attach-agent $node_(1) $a_(1)
$a_(1) attach-vectorbasedforward $opt(width)
$a_(1) cmd set-range 100
$a_(1) cmd set-target-x 0
$a_(1) cmd set-target-y 0
$a_(1) cmd set-target-z 0
$a_(1) set data_rate_ 0.05

set node_(2) [$ns_ node 2]
$node_(2) set sinkStatus_ 1
$god_ new_node $node_(2)
$node_(2) set X_ 0
$node_(2) set Y_ -16
$node_(2) set Z_ 0
$node_(2) set-cx 0
$node_(2) set-cy -16
$node_(2) set-cz 0
$node_(2) set_next_hop 0 ;# target is node 0
#$node_(2) set passive 1
set a_(2) [new Agent/UWSink]
$ns_ attach-agent $node_(2) $a_(2)
$a_(2) attach-vectorbasedforward $opt(width)
$a_(2) cmd set-range 100
$a_(2) cmd set-target-x 0
$a_(2) cmd set-target-y 0
$a_(2) cmd set-target-z 0
$a_(2) set data_rate_ 0.05

set node_(3) [$ns_ node 3]
$node_(3) set sinkStatus_ 1
$god_ new_node $node_(3)
$node_(3) set X_ -30
$node_(3) set Y_ 0
$node_(3) set Z_ 0
$node_(3) set-cx 0
$node_(3) set-cy -30
$node_(3) set-cz 0
$node_(3) set_next_hop 0 ;# target is node 0
#$node_(3) set passive 1
set a_(3) [new Agent/UWSink]
$ns_ attach-agent $node_(3) $a_(3)
$a_(3) attach-vectorbasedforward $opt(width)
$a_(3) cmd set-range 100
$a_(3) cmd set-target-x 0
$a_(3) cmd set-target-y 0
$a_(3) cmd set-target-z 0
$a_(3) set data_rate_ 0.05

#puts "the total number is $total_number"
set node_($total_number) [$ns_ node $total_number]
$god_ new_node $node_($total_number)
$node_($total_number) set X_ 60
$node_($total_number) set Y_ 0
$node_($total_number) set Z_ 0
$node_($total_number) set-cx 60
$node_($total_number) set-cy 0
$node_($total_number) set-cz 0
$node_($total_number) set_next_hop 0 ;# target is node 0
set a_($total_number) [new Agent/UWSink]
$ns_ attach-agent $node_($total_number) $a_($total_number)
$a_($total_number) attach-vectorbasedforward $opt(width)
$a_($total_number) cmd set-range 100
$a_($total_number) cmd set-target-x 0
$a_($total_number) cmd set-target-y 0
$a_($total_number) cmd set-target-z 0
#$a_($total_number) set data_rate_ 0.00005
$a_($total_number) set data_rate_ 0.05

#$ns_ at 15 "$a_($total_number) cbr-start"
$ns_ at $start_time "$a_(1) exp-start"
$ns_ at $start_time "$a_(2) exp-start"
$ns_ at $start_time "$a_(3) exp-start"
$ns_ at $start_time "$a_($total_number) exp-start"

set node_size 10
for {set k 0} { $k<$opt(nn) } { incr k } {
$ns_ initial_node_pos $node_($k) $node_size
}

puts "+++++++AFTER ANNOUNCE++++++++++++++"

$ns_ at $opt(stop).001 "$a_(1) terminate"
$ns_ at $opt(stop).001 "$a_(2) terminate"
$ns_ at $opt(stop).001 "$a_(3) terminate"
$ns_ at $opt(stop).001 "$a_($total_number) terminate"
$ns_ at $opt(stop).002 "$a_(0) terminate"

$ns_ at $opt(stop).003 "$god_ compute_energy"
$ns_ at $opt(stop).004 "$ns_ nam-end-wireless $opt(stop)"
$ns_ at $opt(stop).005 "puts \"NS EXISTING...\"; $ns_ halt"

puts $tracefd "vectorbased"
puts $tracefd "M 0.0 nn $opt(nn) x $opt(x) y $opt(y) z $opt(z)"
puts $tracefd "M 0.0 prop $opt(prop) ant $opt(ant)"
puts "starting Simulation..."
$ns_ runThanks in advance for your help