This document describes the topology and implementation of a wireless network simulation. It includes: 1) Defining different node types (access point, stations, point-to-point, CSMA nodes) and connecting them with various net device and channel types. 2) Configuring the PHY and MAC layers for WiFi nodes using helper classes and setting attributes. 3) Adding mobility to WiFi nodes using mobility models and allocators to set positions while moving within boundaries. 4) Installing the internet stack on nodes and assigning IP addresses. 5) Adding server and client applications to simulate network traffic and running the simulation.

1. Building Topology
[Part-2]

2. Topology
STA-1
STA-2
STA-3
AP
CSMA
P2P
WIFI
P1 P2
C1 C2 C3 C4
CLIENT
SERVER
UdpEchoServerHelper
UdpEchoCientHelper

3. RoadMap
● Writing Code
● Detail Understanding
– Logging
– Tracing
– Attributes

4. Flow Chart
Point To Point
CSMA
WIFI Station
WIFI AP
NODE
Container
Point To Point
CSMA
WIFI Station
WIFI AP
NetDe`vice
Container
Point To Point
CSMA
WIFI Station
WIFI AP
SetAttributes
NetDevice
Point To Point
CSMA
Attach
NetDevice to
PHY
&CHANNEL
WIFI Station
WIFI AP
Configure
PHY & MAC
WIFI Station
WIFI AP
Attach
NetDevice to
PHY
&CHANNEL
Point To Point
CSMA
WIFI Station
WIFI AP
Install
ProtocolStack
Point To Point
CSMA
WIFI Station
WIFI AP
Assign IP
Address
Install Application

5. Topology Description
● Channels & Net Device
– Wireless
– Point to Point
– CSMA
● Node Container
– Access Point Node
– Station Nodes
– Point to Point Nodes
– CSMA Nodes
● Node P1 & P2 having two Net Device of different types

6. Classes
● NodeContainer
● PointToPointHelper
● CsmaHelper
● YansWifiChannelHelper
●
YansWifiPhyHelper
● WifiHelper
● NetDeviceContainer
● MobilityHelper
● InternetStackHelper
● Ipv4AddressHelper
●
Ipv4InterfaceContainer
● UdpEchoServerHelper
● UdpEchoClientHelper
● ApplicationContainer
`
Include
#include "ns3/core-module.h"
#include "ns3/network-module.h"
#include "ns3/csma-module.h"
#include "ns3/internet-module.h"
#include "ns3/point-to-point-module.h"
#include "ns3/applications-module.h"
#include "ns3/ipv4-global-routing-helper.h"

7. NODE
● We are having four different types of nodes.
● Create Four Different NodeContainer
– Point to Point
– Station Nodes
– Access Point
– CSMA NodeContainer n1,n2;
n1.Create(3);
[...]
N2.Create(1);
n2.Add(n1.Get(0));
void Create(uint32_t n);
Add()- used to add node in a node container
Create() - used to create node/s

8. NetDevice and Channel
● Three different NetDevice and Channel:-
– PointToPointHelper – NetDevice & Channel
– CsmaHelper – NetDevice & Channel
– YansWifiChannelHelper – Channel
– YansWifiPhyHelper – PHY
– WifiHelper – NetDevice
We use Install()method to attach NetDevice with Node
It will return an object to NetDeviceContainer

9. Configure WIFI NetDevice
`
NetDevice
PHY
MAC<attach>
YansWifiPhyHelper
NqosWifiMacHelper
YansWifiChannelHelper
WifiHelper
Node

10. Configure WIFI NetDevice
● WifiChannel & WifiPhy abstract class
– YansWifiChannel
● We use Helper [YansWifiChannelHelper]
● Set Channel related attributes
– [channel switch delay, energy of received signal,etc]
– YansWifiPhy
● We use Helper [YansWifiPhyHelper]
● Set PHY Layer related attributes
– [propogation delay] Set CHANNEL to PHY
void SetChannel(Ptr<YansWifiChannel>)-
Class YansWifiPhy

11. Configure MAC
● WifiMac abstract class
– List of MAC Types
● AdhocWifiMac – Infrastructure less network
● ApWifiMac – Access point Node MAC
● StaWifiMac – Station Node MAC
● Etc.
– We use Helper Class
● NqosWifiMacHelper or WifiMacHelper
– Set the appropiate MAC from the list and Set Attributes
● void SetType(T,A,V....);
● T- Type of MAC
● A- Name of Attribute
● V –Value of Attribute

12. Mobility
● It is used to track and maintain the
– Current Cartesian position
– Speed of an object
– Placement of Node
– Setup Mobility Model

13. Mobility
[Cartesian Position]
Source:http://en.wikipedia.org/wiki/Cartesian_coordinate_system

14. Mobility
● Assign Mobility to WIFI Nodes
– List of Mobility Model
● ConstantAccelerationMobilityModel
● ConstantPositionMobilityModel
● ConstantVelocityMobilityModel
● RandomDirection2dMobilityModel
● RandomWalk2dMobilityModel
● Etc
– List of Allocator Model (placement of Node)
● RandomDiscPositionAllocator
● RandomRectanglePositionAllocator
● GridPositionAllocator
● Etc.

15. Mobility Model
● RandomWalk2dMobilityModel
– 2D random walk mobility model
– Each instance moves with a speed and direction
choosen at random
– Nodes moves in Boundaries specified by Rectangle
– Rectangle(double xMin,double xMax,double yMin,double yMax)
x-axis
y-axis
xMin xMax
yMin
yMax

16. Allocator Model
● GridPositionAllocator
– Allocate position on a rectangular 2D grid
– List of Attributes
● MinX
● MinY
● DeltaX
● DeltaY
● GridWidth
● LayoutType
– ROW_FIRST
– COLUMN_FIRST
1 2 3
4
(MinX,MinY) DeltaX
DeltaY GridWidth
x-axis
y-axis

17. Mobility
● We use Helper Class
– MobilityHelper
● SetMobilityModel()-Set Mobility Model
● SetPositionAllocator() - Set Position Allocator
– Install the mobility on Nodes
– Mobility Model [Access Point & CSMA Nodes]
● ConstantPositionMobilityModel

18. Internet Stack & Ipv4Address
● Now its time to install Protocol Stack
– InternetStackHelper
● Install()
● Assign IP address to the NetDevice
– Ipv4InterfaceContainer
● Assign()

19. Application
STA-1
STA-2
STA-3
AP
CSMA
P2P
WIFI
P1 P2
C1 C2 C3 C4
CLIENT
SERVER
UdpEchoServerHelper
UdpEchoCientHelper

20. Animation
● AnimationInterface
– Set Methods for Nodes
● Description – SetNodeDescription(NodeContainer,”AP”)
● Color – SetNodeColor(NodeContainer , R,G,B)
● Position – SetConstantPosition(Node,X,Y)
● Etc.
– Add Background Image
● SetBackgroundImage(..,..,..,);
vodi EnablePacketMetadata(boolean value)

21. Start Simulation
Simulation::Run();
Simulation::Destroy();
return 0;

22. ● Modify the Mobility Pattern using
– RandomWalk2dMobilityModel
● Distance- Change current direction and
speed after moving for this distance.
● Speed – speed of node
● Bounds – Area

23. To be Continued...