View source for Ns-3-Network-Simulator/C3/Creating-an-ad-hoc-wireless-network/English

{| border="1"
|-
|| '''Visual Cue'''
|| '''Narration'''
|-
|| Show Slide: '''Title Slide'''
|| Welcome to Spoken tutorial on '''Creating an Ad-hoc wireless network'''.

|-
|| Show Slide:

'''Learning Objectives'''
|| In this tutorial, we will learn to
* Create an '''Ad-hoc wireless network'''.
* Create three '''UDP flows''' in the channels.
* Analyze the flow using a '''flow monitor'''.
* Visualize the network using '''NetAnim'''

|-
|| Show Slide: 

'''System Requirements'''
|| To record this tutorial, I am using
* '''Ubuntu Linux OS version 22.04.'''
* '''ns-3 version''' 3.38.
* '''NetAnim''' visualizer tool.

|-
|| Show slide: 

'''Prerequisite'''

[https://www.spoken-tutorial.org/ https://www.spoken-tutorial.org]
|| To follow this tutorial
* The learner must have basic knowledge of ns-3 software.
* For pre-requisite ns-3 tutorials, please visit this website

[https://www.spoken-tutorial.org/ https://www.spoken-tutorial.org]
|- 
|| Show Slide:

'''Code Files'''
|| 
* The files used in this tutorial are provided in the '''Code files''' link.
* Please download and extract the files.
* Make a copy and then use them while practicing.

|-
|| Show diagram: '''Ad-hoc network'''
|| For this tutorial, we would be creating the following topology.

We will create a simple '''ad-hoc 2 cross 2 grid with 4 nodes''' in this tutorial. 
|-
|| Open code editor
|| I have created the source file '''wifi-simple-adhoc-grid.cc''' for this program.

The source code contains the required functions to create an '''ad-hoc wireless network'''.

Now we will go through the source code in the text editor.
|-
|| Highlight '''std::string phyMode("DsssRate1Mbps");'''
|| We set the '''dsss rate''' of the '''physical layer''' to '''1 Mbps'''.

|-
|| Highlight '''double distance = 100;'''
|| Let us set the  distance between the nodes as 100 ''' meters'''.
|-
|| Highlight '''uint32_t packetSize = 1000;'''

'''uint32_t numPackets = 100;'''
|| Now we shall set the '''packet size''' to '''1000 bytes'''.

Then let us set the '''number of packets''' to be transmitted as 100.
|-
|| Highlight '''double interval = 0.004;'''
|| We set the '''time interval''' between the '''packet transfer''' as 0.004 '''seconds'''.
|-
|| Highlight '''uint32_t sinkNode = 0;'''

'''uint32_t sourceNode = 3;'''

|| Let us set up the '''source''' and ''' sink nodes''' for the flow that we are yet to create.
|-
|| Highlight '''Config::SetDefault("ns3::WifiRemoteStationManager::NonUnicastMode", StringValue(phyMode));'''

|| We shall configure '''non-unicast mode '''for all the '''station nodes''' in the '''simulation.'''

'''Non-unicast mode''' means that the data may be sent from one node to many nodes.
|-
|| Highlight '''NodeContainer c;'''

'''c.Create(numnodes);'''

|| Now, let us create a '''node container''' with  four '''nodes'''.
|-
|| Highlight '''WifiHelper wifi;'''

'''if (verbose) { WifiHelper::EnableLogComponents(); } '''

'''wifi.SetStandard(WIFI_STANDARD_80211b);'''
|| We shall now put the '''wifi''' '''network interface cards '''together.

For that, let us use the''' WifiHelper class'''.

Using '''Wifi-helper''' class, we '''enable logging components '''and also set the wifi standard.

We set the wifi standard as '''IEEE 802.11b.'''
|-
|| Highlight '''YansWifiPhyHelper wifiPhy;'''

'''wifiPhy.Set("RxGain", DoubleValue(0));'''

|| Then let us use the '''YansWifiPhyHelper class '''to set the '''RxGain attribute''' to''' zero'''.

'''RxGain''' is used to adjust the sensitivity of the '''receiving signal.'''
|-
|| Highlight '''YansWifiChannelHelper wifiChannel;'''

'''wifiChannel.SetPropagationDelay("ns3::ConstantSpeedPropagationDelayModel");'''

'''wifiChannel.AddPropagationLoss("ns3::FriisPropagationLossModel");'''
|| We use '''YansWifiChannelHelper''' '''class''' to set attributes of the '''transmitting channel'''.

Let us set the '''Propagation delay'''.

We shall also add the '''propagation loss''' to our model.
|-
|| Highlight '''wifiPhy.SetChannel(wifiChannel.Create());'''
|| Next, we connect the''' wifi physical layer '''to the '''wifi-channel'''.
|-
|| Highlight '''WifiMacHelper wifiMac;'''

'''wifi.SetRemoteStationManager("ns3::ConstantRateWifiManager","DataMode", StringValue(phyMode), "ControlMode", StringValue(phyMode));'''

||Now let us set a '''constant rate''' for '''data''' and '''control modes '''of '''wifi stations.'''
|-
|| Highlight '''wifiMac.SetType("ns3::AdhocWifiMac");'''
|| Then, we set the '''MAC protocol '''of the '''Wi-Fi network''' to be '''Ad-hoc'''.
|-
|| Highlight '''NetDeviceContainer devices = wifi.Install(wifiPhy, wifiMac, c);'''
|| Let us now connect '''wifiphy, wifimac''' to the''' nodes '''we created.

This above setup includes''' wifiphy '''and '''wifimac. '''

|-
|| Highlight '''MobilityHelper mobility;'''

'''mobility.SetPositionAllocator("ns3::GridPositionAllocator",'''

'''"MinX",'''

'''DoubleValue(0.0),'''

'''"MinY",'''

'''DoubleValue(0.0),'''

'''"DeltaX",'''

'''DoubleValue(distance),'''

'''"DeltaY",'''

'''DoubleValue(distance),'''

'''"GridWidth",'''

'''UintegerValue(2),'''

'''"LayoutType",'''

'''StringValue("RowFirst"));'''
|| Now allocate the positions for the '''nodes''' created using '''MobilityHelper'''.

Here, we are assigning positions of the '''nodes''' in a '''grid''' arrangement.

'''MinX''' and '''MinY''' refers to minimum values of '''x '''and''' y''' '''axes''' which are set to zero. 

'''DeltaX '''and '''DeltaY''' parameters define spacing between '''nodes''' in the '''x''' and ''' y axes'''.

|-
|| Highlight '''mobility.SetMobilityModel("ns3::ConstantPositionMobilityModel");'''

'''mobility.Install(c);'''

|| Let us set the model to be '''ConstantPositionMobilityModel.'''

It represents the stationary or '''static nodes''' in a '''network simulation.'''

Also, '''install '''the model that we '''set''', to all the '''nodes''' that we created. 
|-
|| Highlight '''OlsrHelper olsr;'''

|| Now we shall enable the '''OLSR protocol''' in the '''network channels'''.

'''OLSR''' refers to '''Optimized link state routing protocol '''.

It maintains the '''routing table''' of all the '''station nodes'''.
|-
|| Highlight '''Ipv4ListRoutingHelper list;'''

'''list.Add(olsr, 0);'''

|| Then let us add the list of nodes to assign '''Ipv4 addresses'''.

'''0 '''refers to high priority to '''OLSR protocol '''to be added to the nodes.
|-
|| Highlight '''InternetStackHelper internet;'''

'''internet.SetRoutingHelper(list); '''

'''internet.Install(c);'''
|| Then let us install the''' internet stack''' on all the nodes.
|-
|| Highlight '''Ipv4AddressHelper ipv4;'''

'''ipv4.SetBase("10.1.1.0", "255.255.255.0");'''

'''Ipv4InterfaceContainer i = ipv4.Assign(devices);'''

|| Now, we shall '''assign IP addresses''' to the '''nodes''' that we created.

'''Base address''' and''' subnet mask''' are assigned to the station nodes of the network. 
|-
|| Highlight '''TypeId tid = TypeId::LookupByName("ns3::UdpSocketFactory");'''

|| The highlighted command is used to get the '''TypeId''' of '''UdpSocketFactory.'''

|-
|| Highlight '''Ptr<Socket> recvSink = Socket::CreateSocket(c.Get(sinkNode), tid);'''
|| We shall create a receiving '''socket''' for the '''UDP Flow'''. 
|-
|| Highlight '''InetSocketAddress local = InetSocketAddress(Ipv4Address::GetAny(), 80);'''
|| Let us create an '''internet socket''' '''address''' using any '''IPv4 address''' and '''port 80.'''
|-
|| Highlight '''recvSink->Bind(local);'''
|| Then bind the '''receiving socket''' to the '''local address''' and to the '''port 80'''.
|-
|| Highlight '''recvSink->SetRecvCallback(MakeCallback(&ReceivePacket));'''
|| Now set the '''receive''' '''callback function''' for the '''receiving socket'''.

When the '''packet '''is received in the''' sinknode,''' we call '''RecievePacket function'''.
|-
|| Highlight '''Ptr<Socket> source = Socket::CreateSocket(c.Get(sourceNode), tid);'''
|| Let us then create an '''UDP socket '''on '''node 3, '''which is our '''sourcenode'''.
|-
|| Highlight '''InetSocketAddress remote = InetSocketAddress(i.GetAddress(sinkNode, 0), 80);'''
|| Let us create an''' internet socket '''using '''Ipv4 address''' of '''sinknode''' and '''port 80'''.
|-
|| Highlight '''source->Connect(remote);'''
|| Let us connect the '''source socket '''to the '''remote address''' and '''port 80.''' 
|-
|| Highlight '''void'''

'''ReceivePacket(Ptr<Socket> socket)'''

'''{'''

'''while (socket->Recv()){ }'''

'''}'''
|| Now let’s define the function to '''call''' when the '''packets''' are received. 


Here, we are invoking the '''receive functionality''' of the '''socket'''.
|-
|| Highlight '''static void'''

'''GenerateTraffic(Ptr<Socket> socket, uint32_t pktSize, uint32_t pktCount, Time pktInterval)'''

|| Then let us define a function called '''generate packet traffic'''. 
|-
|| 

|| When the '''number of''' '''packets''' is not''' zero''', we invoke the '''send ''' function.

We also schedule the '''simulator '''to invoke the ''' GenerateTraffic function.'''

When the '''number of packets''' is zero, we close the '''socket'''.

Then, we '''stop invoking send function'''.
|-
|| Only Narration
|| We have created three other '''UDP flows''' as well.
|-
|| Highlight '''Simulator::Schedule(Seconds('''

'''10),&GenerateTraffic,source,packetSize,numPackets,interval);'''
|| Let us schedule the '''simulator''' to '''callback''' the '''generate_traffic function.'''

This procedure happens after ten seconds from the start of '''execution'''.
|-
|| Highlight '''Ptr<FlowMonitor> flowMonitor;'''
|| Then, '''Initialize''' flow monitor for tracing.
|-
|| HIghlight '''FlowMonitorHelper flowHelper;'''

'''flowMonitor= flowHelper.InstallAll();'''

|| We shall then install a '''flow monitor''' on all the '''nodes'''.
|-
|| Highlight '''AnimationInterface anim ("animationwifi-adhoc-wireless.xml"); '''
|| Let us create the''' XML output''' of the program.
|-
|| HIghlight '''Ptr<Ipv4FlowClassifier> classifier=DynamicCast<Ipv4FlowClassifier> (flowHelper.GetClassifier());'''
|| Let us now create an object of the '''Ipv4FlowClassifier class.'''

The created '''object '''returns a ''' pointer''' to the '''flow classifier.'''

|-
|| Highlight '''std::map<FlowId,FlowMonitor::FlowStats> stats=flowMonitor->GetFlowStats();'''
|| To store the information about the '''network flow''', let us use this command.
|-
|| Highlight the '''entire for loop.'''
|| Let’s retrieve the details of the flow using a '''for loop.'''

'''iter arrow first '''is used to collect the '''ID''' of the '''flow.'''

'''iter arrow second '''is used to collect the '''data '''associated with the''' flow'''.

We will analyze the '''type of flow''' and '''print''' the''' delay''' and '''throughput'''.

|-
|| Highlight '''Simulator::Destroy()'''
|| The '''Destroy() '''function ends the simulation.
|-
|| Go to terminal and navigate to the '''ns-allinone-3.38/ns3.38 '''directory
|| Now we will observe the simulation.

Open the terminal by pressing '''Ctrl''', '''Alt''' and '''T keys''' simultaneously.

Using the '''cd '''command, navigate to the installation directory of ns-3.

Go to the '''ns3.38''' directory.

Move your '''source file''' to the '''scratch '''directory within the '''ns-3.38 directory'''.
|-
|| Type ./'''ns3 run scratch/wifi-simple-adhoc-grid.cc'''
|| Run the command ./'''ns3 run scratch/wifi-simple-adhoc-grid.cc '''

'''wifi-simple-adhoc-grid.cc '''is the name of the source file. 
|-
|| Keep the terminal open and show the output of the command 
|| After compilation, we get the details of the '''packet transfer'''.

We also see the '''average end to end delay''' and''' throughput '''of the wireless network.

|-
|| Navigate to '''netanim '''directory under '''ns-allinone-3.38'''

Type '''cd ..'''
Type '''cd netanim'''

|| Now, to visualize the network, we will use '''NetAnim'''. 

Navigate to the '''netanim '''directory under '''ns-allinone-3.38.'''

For that, type '''cd .. '''in the terminal window.

Then type '''cd netanim'''
|-
|| Type ./'''NetAnim'''
|| Now type '''./NetAnim. '''

The '''NetAnim''' window should open.
|-
|| Click on the Open''' XML trace file '''icon on the top left corner of the window.
|| Click on the Open''' XML trace file '''icon on the top left corner of the window.
|-
|| In the file picker, navigate to the '''ns-allinone-3.38/ns3.38 '''directory and select the '''animationwifi-adhoc-wireless.xml '''file.
|| In the file picker, '''navigate '''to the '''ns-allinone-3.38, '''then to''' ns-3.38 '''directory.

Then select the '''animationwifi-adhoc-wireless.xml '''file.
|-
|| On the toolbar, click on the play button
|| On the toolbar, '''click''' on the '''play button''' to view the''' simulation.'''

We see the '''flow''' of the''' wireless network.'''

Now we can close the '''netanim '''window.
|-
|| Show Slide: '''Summary'''
|| This brings us to the end of this tutorial. Let us summarize. 

In this tutorial, we have

* Created an '''Ad-hoc''' '''wireless network'''.
* Created three '''UDP flows''' in the channels.
* Analyzed the flow using a '''flow monitor'''.
* Visualized the network using NetAnim.

|-
|| Show Slide : '''Assignment'''
|| As an assignment, please do the following

* Create a '''three cross three''' grid
* Create''' six UDP flows'''.
* The simulation should run for '''200 seconds.'''
* Analyze the '''flow''' using a '''flow monitor.'''
* Visualize the network using '''NetAnim.'''

|-
|| Show terminal window

Type '''cd ..'''

Type '''cd ns-3.38'''

Type '''./ns3 run scratch/exp-10assignment.cc'''

|| In the terminal window, you will get the following output.

We could see the details of all the six flows.
|-
|| Show Slide:

'''Assignment - Observation'''
|| In the NetAnim window, you would observe the following output.

Observe the packet transfer.
|- 
|| Show Slide:

'''About Spoken Tutorial Project'''
|| The video at the following link summarizes the '''Spoken Tutorial project'''.

Please download and watch it.
|- 
|| Show Slide:

'''Spoken Tutorial Workshops'''
|| The '''Spoken Tutorial Project''' team conducts workshops and gives certificates.

For more details, please write to us.
|- 
|| Show Slide:

'''Answers for THIS Spoken Tutorial'''
|| Please post your timed queries in this forum.
|- 
|| Show Slide:

'''FOSSEE Forum'''
|| For any general or technical questions on ns-3, visit the''' FOSSEE forum''' and post your question.
|- 
|| Show Slide: '''Acknowledgement'''
|| '''Spoken Tutorial''' Project was established by the '''Ministry of Education, Government of India'''.
|- 
|| Show Slide: 

'''Acknowledgement'''
|| We thank '''Dr. Moyukh Laha''' from '''IIT Kharagpur''' for his domain support.

We would also like to thank '''Dr. R. Radha, Dr. X. Anita, '''and''' Dr. T. Subbulakshmi '''from''' VIT Chennai '''for their support.
|- 
|| Show Slide: 

'''Thank you'''
|| This is '''Arun Santhosh,''' a FOSSEE Summer Fellow 2023, IIT Bombay signing off.

Thank you for joining.
|-
|}