[ns] Transmission and Interference Range
Hi, Can you tell me a clean way to change transmission and interference ranges in ns-2? I tried the threshold program given ~ns/indep-utils/propagation/ but that somehow is not giving correct values. Regards, -- Ashish Sangwan B.Tech, Computer Science & Engineering IIT Delhi -- I do know everything, just not all at once. It's a virtual memory problem.
Re: [ns] Transmission and Interference Range
Hi ,
I didnot know about these three transmit power levels. Thanks Iqbal for
that.
I wanted to have Interference Range(Carrier Sense Range) to be twice the
Communication Range. So I achieved by calculating CSThresh_ value by
following formula
Pt * Gt * Gr * (hr * hr * ht * ht) / {(Required interference range) ^ 4}
--Ashish
On 7/13/06, Q.R.Iqbal <[EMAIL PROTECTED]> wrote:
>
> Hi there
>
> I think there is no other cleaner or easiar way to do that unless you
> modify the code.
>
> One thing you have to be aware of is that by modifying the transmission
> range, you are only changing the receiver threshold, A distance from
> which a receiver can receive.
>
> Again there are three different transmit power levels that are given for
> the wavelan Modem
>
> 40m 8.5872e-4
> 100m 7.214e-3
> 250m 02818
>
> Maybe you need to use one of these parameters, the closest to your
> required transmission range and then calculate the RXthreshold values, to
> get a better result.
> Also you need to be aware of CSthreshold,. If you are limiting the node's
> transmission range to 40m or 100m or any value, the CSthreshold value,
> will still be very large, about 550m by default, you might also want to
> tweak that parameter to see if this improves your results
>
> I hope this helps
>
> > Hi,
> >
> > Can you tell me a clean way to change transmission and interference
> ranges
> > in ns-2?
> > I tried the threshold program given ~ns/indep-utils/propagation/ but
> that
> > somehow is not giving correct values.
> >
> > Regards,
> > --
> > Ashish Sangwan
> > B.Tech, Computer Science & Engineering
> > IIT Delhi
> >
> > --
> > I do know everything, just not all at once. It's a virtual memory
> problem.
> >
>
>
> Kind regards
>
> Qasim Raza Iqbal
> PhD Candidate,
> ACNRG Lab N504, Office N505
> Adaptive Communications Networks Research Group,
> School of Engineering And Applied Science
> Aston University
> Birmingham B4 7ET
> United Kingdom
> http://www.ee.aston.ac.uk/research/acrg/index.html
>
>
>
Re: [ns] Transmission and Interference Range
Hi there I think there is no other cleaner or easiar way to do that unless you modify the code. One thing you have to be aware of is that by modifying the transmission range, you are only changing the receiver threshold, A distance from which a receiver can receive. Again there are three different transmit power levels that are given for the wavelan Modem 40m 8.5872e-4 100m 7.214e-3 250m 02818 Maybe you need to use one of these parameters, the closest to your required transmission range and then calculate the RXthreshold values, to get a better result. Also you need to be aware of CSthreshold,. If you are limiting the node's transmission range to 40m or 100m or any value, the CSthreshold value, will still be very large, about 550m by default, you might also want to tweak that parameter to see if this improves your results I hope this helps > Hi, > > Can you tell me a clean way to change transmission and interference ranges > in ns-2? > I tried the threshold program given ~ns/indep-utils/propagation/ but that > somehow is not giving correct values. > > Regards, > -- > Ashish Sangwan > B.Tech, Computer Science & Engineering > IIT Delhi > > -- > I do know everything, just not all at once. It's a virtual memory problem. > Kind regards Qasim Raza Iqbal PhD Candidate, ACNRG Lab N504, Office N505 Adaptive Communications Networks Research Group, School of Engineering And Applied Science Aston University Birmingham B4 7ET United Kingdom http://www.ee.aston.ac.uk/research/acrg/index.html
Re: [ns] Transmission and Interference Range
Check this code that I'm using to set the power based on the circular
distance in meters:
Usage:
set coverage [CellCoverage 1 1 $MAX_X $MAX_Y $OVERLAP]
set power [SetPt $coverage]
Phy/WirelessPhy set Pt_ $power
$ns node-config -rxPower $power -txPower $power
-
###
###
### generic POWER functions
#
# Given overlaping area, calculate the desired coverage
# expects a BOUNDING BOX for the cell, with the mobile in the center
#
proc CellCoverage { x1 y1 x2 y2 overlap} {
set d2 [expr ($x2-$x1)*($x2-$x1) + ($y2-$y1)*($y2-$y1)]
set d [expr sqrt($d2)] ;#
Hipotenusa
set ret [expr ($overlap + $d) / 2]
puts "D2: $d2 D: $d RET: $ret"
return $ret
}
#
# Given overlaping area, calculate the desired coverage
# expects a QUARTER BOUNDING BOX for the cell, with the mobile in the 0,0
position (lower left corner)
#
proc HalfCellCoverage { x1 y1 x2 y2 overlap } {
return [expr [CellCoverage $x1 $y1 $x2 $y2 $overlap] * 2]
}
#
# Calculate Necessary Transmission Power Pt for given coverage
#
# See /mobile/tworayground.cc
#
proc SetPt { coverage } {
set Gt [Antenna/OmniAntenna set Gt_]
set Gr [Antenna/OmniAntenna set Gr_]
set ht [Antenna/OmniAntenna set Z_]
set hr [Antenna/OmniAntenna set Z_]
set RXThresh [Phy/WirelessPhy set RXThresh_]
set L [Phy/WirelessPhy set L_]
set Pt_ [Phy/WirelessPhy set Pt_]
set freq_ [Phy/WirelessPhy set freq_]
set lambda [expr 3 / $freq_]
set crossover_dist [expr (4 * 3.1415926535897 * $ht * $hr) / $lambda
];
puts "old pt: $Pt_ RXThresh: $RXThresh lambda: $lambda \t\t
crosshover: $crossover_dist coverage: $coverage"
if { [expr $coverage < $crossover_dist] } {
puts ">>> Using Friis formula <<<"
set M [expr $lambda / (4.0 * 3.1415926535897 * $coverage)]
set Pt [expr $RXThresh * ($L / ($Gt*$Gr*$M*$M))]
puts " RET: $Pt"
} else {
puts ">>> Using TwoRay formula <<<"
#Calculate input power necessary to have, at dist $coverage,
output power = $RXThresh
set d4 [expr pow($coverage,4)]
set Pt [expr $RXThresh * (($L*$d4) /
($Gt*$Gr*$ht*$ht*$hr*$hr))]
puts "D4: $d4 RET: $Pt"
}
#debug 1
return $Pt
}
#/*
# * Friis free space equation:
# *
# * Pt * Gt * Gr * (lambda^2)
# * P = --
# * (4 * pi * d)^2 * L
# */
# from /mobile/tworayground.cc:
#
# TwoRayGround formula
# power = Pt * Gt * Gr * (hr * hr * ht * ht) / (d * d * d * d * L);
#
#
> -Original Message-
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf
> Of Ashish Sangwan
> Sent: quinta-feira, 13 de Julho de 2006 14:59
> To: Q. R. Iqbal
> Cc: ns-users@ISI.EDU
> Subject: Re: [ns] Transmission and Interference Range
>
>
> Hi ,
>
> I didnot know about these three transmit power levels. Thanks Iqbal for
> that.
> I wanted to have Interference Range(Carrier Sense Range) to be twice the
> Communication Range. So I achieved by calculating CSThresh_ value by
> following formula
> Pt * Gt * Gr * (hr * hr * ht * ht) / {(Required interference range) ^ 4}
>
> --Ashish
>
> On 7/13/06, Q.R.Iqbal <[EMAIL PROTECTED]> wrote:
> >
> > Hi there
> >
> > I think there is no other cleaner or easiar way to do that unless you
> > modify the code.
> >
> > One thing you have to be aware of is that by modifying the transmission
> > range, you are only changing the receiver threshold, A distance from
> > which a receiver can receive.
> >
> > Again there are three different transmit power levels that are given for
> > the wavelan Modem
> >
> > 40m 8.5872e-4
> > 100m 7.214e-3
> > 250m 02818
> >
> > Maybe you need to use one of these parameters, the closest to your
> > required transmission range and then calculate the RXthreshold values,
> to
> > get a better result.
> > Also you need to be aware of CSthreshold,. If you are limiting the
> node's
> > transmission range to 40m or 100m or any value, the CSthreshold value,
> > will still be very large, about 550m by default, you might also want to
> > tweak that parameter to see if this improves your results
> >
> > I hope this helps
> >
> >
