Hi All,
After hacking threshold.cc, I've known the formula used to calculate
receive
threshold (ATTENTION: threshold.cc only generates RXThresh_, NOT Pt_). I
modified
TwoRayGround formula in threshold.cc, as below :
Pr * d^4 * L
Pt = ---------------------------
Gt * Gr * (ht^2 * hr^2)
Pr is replace with RXThresh_ whose value is 3.652e-10.
If a distance is given, Pt can be calculated by above formula.
e.g.
Tx Range Pt_
100m 0.00721383
150m 0.03652
200m 0.115421
250m 0.28179
300m 0.58432
... ...
I attached modified threshold.cc renamed threshold_Pt.cc .
After compiling it, you can use like this:
./threshold_Pt -m TwoRayGround <Required TxRange>
But unluckily, if the tx range is smaller than crossover_dist (always should
be 86.1425m),
the generated Pt_ value is incorrect either using Friis or TwoRay.
If you know why, please let me know.
I've developed a simple tcl script in order to validate transmit range
with different Pt_ value. I attached this script named TxRangeTest.tcl.
The routing protocol used in the script is MFlood, which is just a simple
flooding algorithm. Trace format has been changed a little, like:
s 1.000000000 1 1.00 200.00 AGT --- 0 cbr 512 [0 0 0 0] -------
[1:0 0:0 32 0] [0] 0 0
r 1.004860003 0 0.00 200.00 AGT --- 0 MFlood 532 [mflood 1.000000000
1.00 200.00 ]
The trace format of cbr packet can be referred to NS2 manual. The explain
of trace format about
MFlood packet is below:
event = $1;
curr_time = $2;
curr_node_id = $3;
curr_position_x = $4;
curr_position_y = $5;
trace_type = $6;
pkt_seq = $8;
pkt_type = $9;
pkt_generate_time = $12;
prev_hop_position_x = $13;
prev_hop_position_y = $14;
Finally, a AWT file is used to calculate the transmit range.
#========================================================================
BEGIN {
RecvNum = 0;
final_curr_position_x = 0;
final_curr_position_y = 0;
final_prev_hop_position_x = 0;
final_prev_hop_position_y = 0;
}
{
event = $1;
curr_time = $2;
curr_node_id = $3;
curr_position_x = $4;
curr_position_y = $5;
trace_type = $6;
pkt_seq = $8;
pkt_type = $9;
pkt_generate_time = $12;
prev_hop_position_x = $13;
prev_hop_position_y = $14;
if ( event == "r" && curr_node_id == 0 && trace_type == "AGT" )
{
RecvNum++;
# printf(" %3d [Time : %f] N0(%.2f,%.2f) <----
N1(%.2f,%.2f)\n",
# RecvNum,
# curr_time,
# curr_position_x,
# curr_position_y,
# prev_hop_position_x,
# prev_hop_position_y);
final_curr_position_x = curr_position_x;
final_curr_position_y = curr_position_y;
final_prev_hop_position_x = prev_hop_position_x;
final_prev_hop_position_y = prev_hop_position_y;
}
}
END{
dx = final_prev_hop_position_x - final_curr_position_x ;
dy = final_prev_hop_position_y - final_curr_position_y ;
tx_range = sqrt(dx * dx + dy * dy) ;
printf(" \nNum of Recv pkts : %d \n", RecvNum);
printf(" \nTx Range of Node 1: %f \n", tx_range);
}
This is just a reference. You should do some changes according to
your trace file if you use other routing protocol.
Regards,
Phenix
--------------------------------------------------
From: "kavan sheth" <shethka...@gmail.com>
Sent: Sunday, January 04, 2009 1:24 PM
To: "Phenix" <phenix...@hhu.edu.cn>
Subject: Re: [ns] how to set different transmit range for different node
Hi Phenix,
As far as I know threshold.cc generates particular transmission
power(Pt_) based on the propagation model and distance specified by
you. different propagation model have different equations for
receiving power based on its characteristics. different equations are
given in the threshold.cc. you can know more by studying this
threshold.cc
Kavan
On 1/3/09, Phenix <phenix...@hhu.edu.cn> wrote:
Hi Sidney,
After times of trials, I've succeeded in letting different nodes own
different
Tx Range by configuring different value of Pt_ for each node. I get
different
values of Pt_ from a script:
# The transimssion radio range
Pt_ 6.9872e-4 ;# ?m
Pt_ 8.5872e-4 ;# 40m
Pt_ 1.33826e-3 ;# 50m
Pt_ 7.214e-3 ;# 100m
Pt_ 0.2818 ;# 250m
And in my script, I have test range of 250m and 40m. It really works
well.
But It's a pity that I don't know how to obtain these values. The tool
threshold
(~ns/lidep-utils/propagation/threshold.cc) only generate RXThresh_ other
than Pt_.
Is there somebody knowing how to get value of Pt_?
[Here is my test script]
# ======================================================================
# Define options
# ======================================================================
set val(ifqlen) 50 ;# max packet in ifq
set val(nn) 2 ;# number of
mobilenodes
set val(rp) MFlood ;# routing
protocol,DumbAgent
set val(chan) Channel/WirelessChannel
set val(prop) Propagation/TwoRayGround
set val(netif) Phy/WirelessPhy
set val(mac) Mac/802_11
set val(ifq) Queue/DropTail/PriQueue
set val(ll) LL
set val(ant) Antenna/OmniAntenna
set val(stop) 150
# Initialize the SharedMedia interface with parameters to make
# it work like the 914MHz Lucent WaveLAN DSSS radio interface
Phy/WirelessPhy set CPThresh_ 10.0
Phy/WirelessPhy set CSThresh_ 1.559e-11
Phy/WirelessPhy set RXThresh_ 3.652e-10
Phy/WirelessPhy set Rb_ 2*1e6
Phy/WirelessPhy set freq_ 914e+6
Phy/WirelessPhy set L_ 1.0
# Pt_
set txpower_(0) 0.2818 ;# 250m
set txpower_(1) 8.5872e-4 ;# 40m
set txpower_(2) 7.214e-3 ;# 100m
# ======================================================================
# Main Program
# ======================================================================
#ns-random 0
# Initialize Global Variables
set ns_ [new Simulator]
set tracefd [open mflood_txRange.tr w]
$ns_ trace-all $tracefd
set namtrace [open mflood_txRange.nam w]
$ns_ namtrace-all-wireless $namtrace 1000 500
# set up topography
set topo [new Topography]
$topo load_flatgrid 1000 500
# Create God
create-god $val(nn)
# Create the specified number of mobilenodes [$val(nn)] and "attach" them
# to the channel.
# configure node
set channel [new Channel/WirelessChannel]
$channel set errorProbability_ 0.0
$ns_ node-config -adhocRouting $val(rp) \
-llType $val(ll) \
-macType $val(mac) \
-ifqType $val(ifq) \
-ifqLen $val(ifqlen) \
-antType $val(ant) \
-propType $val(prop) \
-phyType $val(netif) \
-channel $channel \
-topoInstance $topo \
-agentTrace ON \
-routerTrace OFF\
-macTrace OFF \
-movementTrace OFF
for {set i 0} {$i < $val(nn) } {incr i} {
Phy/WirelessPhy set Pt_ $txpower_($i)
set node_($i) [$ns_ node]
$node_($i) random-motion 0;
}
# Provide initial (X,Y, for now Z=0) co-ordinates for mobilenodes
#
# N_0 <-- d ---> N_2
# src dst
$node_(0) set X_ 0.0
$node_(0) set Y_ 200.0
$node_(0) set Z_ 0.0
$node_(1) set X_ 1.0
$node_(1) set Y_ 200.0
$node_(1) set Z_ 0.0
$ns_ at 1.5 "$node_(1) setdest 255.0 200.0 2.0"
# Define node initial position in nam
for {set i 0} {$i < $val(nn)} {incr i} {
$ns_ initial_node_pos $node_($i) 20
}
set udp_(0) [new Agent/UDP]
set udp_(1) [new Agent/UDP]
$ns_ attach-agent $node_(0) $udp_(0)
$ns_ attach-agent $node_(1) $udp_(1)
set null_(0) [new Agent/Null]
set null_(1) [new Agent/Null]
$ns_ attach-agent $node_(1) $null_(0)
$ns_ attach-agent $node_(0) $null_(1)
$ns_ connect $udp_(0) $null_(0)
$ns_ connect $udp_(1) $null_(1)
for {set i 0} {$i < $val(nn)} {incr i} {
set cbr_($i) [new Application/Traffic/CBR]
$cbr_($i) set packetSize_ 512
$cbr_($i) set interval_ 2
$cbr_($i) set random_ 1
$cbr_($i) attach-agent $udp_($i)
}
$ns_ at 1.0 "$cbr_(0) start"
$ns_ at 1.1 "$cbr_(1) start"
# Tell nodes when the simulation ends
for {set i 0} {$i < $val(nn) } {incr i} {
$ns_ at $val(stop).0 "$node_($i) reset";
}
$ns_ at $val(stop).0 "stop"
$ns_ at $val(stop).01 "puts \"NS EXITING...\" ; $ns_ halt"
proc stop {} {
global ns_ tracefd namtrace
$ns_ flush-trace
close $tracefd
close $namtrace
}
puts "Starting Simulation..."
$ns_ run
Regards,
Phenix
From: Sidney Doria
Sent: Saturday, January 03, 2009 12:01 AM
To: Phenix
Subject: Re: [ns] how to set different transmit range for different node
Hi Phenix,
In the TCL file, there's a loop for node creation. So, you can break this
node in a manual creation, each node with specific characteristics.
Sidney Doria
UFCG / BRAZIL
2009/1/2 Phenix <phenix...@hhu.edu.cn>
Hi all,
I'd like how to set different transmit range for different node in
MANET.
eg.
Three nodes,N0,N1 and N2 are in a line:
(N0) (N1) (N2)
|--- 200m -----| ---120m---|
The transmit range of N0,N1 and N2 is respectively 250m,150m,200m.
So packets can be passed:
N0 --> N1 <---> N2
Let me know how to set different transmit range please.
Thank you in advance!
Regards,
Phenix
--
Sidney Doria
Redes ad hoc móveis
Doutorado em Computação
UFCG
Brasil
"Nessa jornada, o conhecimento será o seu escudo..."
(Mestre dos Magos no episódio do grimoire de ouro)
