#Data transmission between all nodes to Sink
set now [$ns now]
for {set i 1} {$i < $val(nn) } { incr i } {
set udp [new Agent/UDP]
$ns attach-agent $node_($i) $udp
set cbr [new Application/Traffic/CBR]
$cbr set packetSize_ 100
$cbr set interval_ 0.1
$cbr attach-agent $udp
set null [new Agent/Null]
$ns attach-agent $node_(0) $null
$ns connect $udp $null
$ns at [expr $now+$i*0.1] "$cbr start"
$ns at [expr ($now+0.1)+$i*0.1] "$cbr stop"
}