wireless tcl script

1. Introduction to Network Simulator (NS2)

2. 2
Introduction to Network Simulator (NS2)

3. 3
Outline
Introduction
NS-2 : Components
Installation of ns2
Implementation of Wireless Sensor Network
Design and develop code for mobility in DTN
Schedule
References

4. 4
NS2 –Network Simulator
ns-2 is a discrete event network simulator for wired and wireless networks alike
It is popular for its extensibility (due to its open source model)
Supports an array of popular network protocols
Popularly used in the simulation of routing and multicast protocols, and is heavily used in ad-hoc research
ns-2 is written in C++ and OTcl
OTcl = Tcl + OO
C++ implements the code that executed frequently
OTcl configures the system

5. 5
NS-2 : Components
NS – Simulator
NAM – Network AniMator
 visual demonstration of NS output
Preprocessing
Handwritten TCL or
Traffic and topology generators
Post analysis
Trace analysis using :
Perl/TCL/AWK/MATLAB
ProblemsSimulate the environmentRun with ns-2Analysis the resultFinishModifyNoFinish the simulationYes

6. 6
Basic Requirements: NS-2
A computer which is having access to the Internet
Minimum 512Mb RAM
Operating system: Linux(Ubuntu 12.04)
ns-2.34 package(ns-allinone)
gcc-4.4.3

7. Installation
Download NS-allinone-2.34 package
http://www.isi.edu/nsnam/ns/
 for easy installation, download ns-allinone
 includes Tcl, Otcl, TclCL, ns, nam, etc.
Works on Unix and cygwin for windows 9x/2000/xp.
After successful downloading and unzipping install allinone package , install NS by
install by calling ~/ns-allinone-2.34/install
After successful installation , Validate the scripts by running ./validate in ~/ns-allinone-2.34/ns-2.34/
 Its now all set to work with NS
7

8. 8
Steps to set up the simulation for wireless script
Mobile node at core of mobility model
Mobile nodes can move in a given topology, receive/transmit signals from/to wireless channels
Scenario : Simple 2 Nodes Simulation
Simulate a very simple 2-node wireless scenario
The topology consists of two mobile nodes
The mobile nodes move about within 500mX500m area
A TCP connection is setup between the two
Mobile nodes.
Packets are exchanged between the nodes as they come within hearing range of one another.

9. 9
Setting Up Variables

set val(chan) Channel/WirelessChannel ;# channel type
set val(prop) Propagation/TwoRayGround ;# radio-propagation model
set val(ant) Antenna/OmniAntenna ;# Antenna type
set val(ll) LL ;# Link layer type
set val(ifq) Queue/DropTail/PriQueue ;# Interface queue type
set val(ifqlen) 50 ;# max packet in ifq
set val(netif) Phy/WirelessPhy ;# network interface type
set val(mac) Mac/802_11 ;# MAC type
set val(rp) DSDV ;# ad-hoc routing protocol
set val(nn) 2 ;# number of mobilenodes
set val(x) 500 ;# X dimension of topography
set val(y) 500 ;# Y dimension of topography

10. 10
Setting Up Variables
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Define NS simulator
•set ns_ [new Simulator] Define trace file
•set tracefd [open simple.tr w]
•$ns_ trace-all $tracefd Create topology object
•set topo [new Topography] Topography object with (x=500, y=500)
•$topo load_flatgrid 500 500

11. 11
God (General Operations Director) Object
.
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Create God object:
create-god $val(nn) God object stores:
number of mobile nodes
table of shortest number of hops required to reach from one node to another
Stores smallest number of hops from one node to another
Optimal case to compare routing protocol performance

12. 12
Simple Configuration For Wireless Nodes

$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)
-topoInstance $topo
-channelType $val(chan)
-agentTrace ON
-routerTrace ON
-macTrace OFF
-movementTrace OFF

13. 13
Configuring Movement
 Create two nodes
Provide initial (X,Y, for now Z=0) co-ordinates
for {set i 0} {$i < $val(nn) } {incr i} {
set node_($i) [$ns_ node ]
$node_($i) random-motion 0 ;# disable random motion
}
$node_(0) set X_ 5.0
$node_(0) set Y_ 2.0
$node_(0) set Z_ 0.0
$node_(1) set X_ 390.0
$node_(1) set Y_ 385.0
$node_(1) set Z_ 0.0

14. 14
Produce some node movements

Explanation:
#Node_(1) starts to move towards node_(0)
$ns_ at 50.0 "$node_(1) setdest 25.0 20.0 15.0"
$ns_ at 10.0 "$node_(0) setdest 20.0 18.0 1.0”
#Node_(1) then starts to move away from node_(0)
$ns_ at 100.0 "$node_(1) setdest 490.0 480.0 15.0“
$ns_ at 50.0 "$node_(1) setdest 25.0 20.0 15.0" means at time 50.0s, node1 starts to move towards the destination (x=25,y=20) at a speed of 15m/s.

15. 15
Setup traffic flow
TCP connections between node_(0) and node_(1)
set tcp [new Agent/TCP]
set sink [new Agent/TCPSink]
$ns_ attach-agent $node_(0) $tcp
$ns_ attach-agent $node_(1) $sink
$ns_ connect $tcp $sink
set ftp [new Application/FTP]
$ftp attach-agent $tcp
$ns_ at 10.0 "$ftp start"

16. 16
Set Stop Time and Start Simulation
Tell nodes when the simulation ends
Finally, Start The Simulation
for {set i 0} {$i < $val(nn) } {incr i} {
$ns_ at 150.0 "$node_($i) reset";
}
$ns_ at 150.0001 "stop"
$ns_ at 150.0002 "puts "NS EXITING...“ ; $ns_ halt"
proc stop {} {
global ns_ tracefd
close $tracefd
}
puts "Starting Simulation..."
$ns_ run

17. 17
Running the Script
The file “simple-wireless.tcl” is under <root>/ns- allinone2.34/ns-2.34/simple-wireless.tcl
 cd into the directory and type “ns simple-wireless.tcl” to run the simulation
The simulation will generate a trace file named “simple.tr”

18. 18
Schedule
Phase 1
Literature Review and Forming Objective
Phase 2
Implementation
Phase 3
Testing and Analysis
Phase 4
Report Writing

19. 19
References
http://www.isi.edu/nsnam/ns
Tutorials
Marc Greis’s Tutorial (http://www.isi.edu/nsnam/ns/tutorial/index.html)
Ns by example (http://nile.wpi.edu/NS/)
Wireless Tutorial (http://www.isi.edu/nsnam/ns/ns- tutorial/wireless.ppt )
Doc:
ns by Example
http://nile.wpi.edu/NS/
NS Manual:
 http://www.isi.edu/nsnam/ns/doc/index.html
Workshop and presentations
 http://www.isi.edu/nsnam/ns/ns-tutorial/index.html

20. 20
Q & A