/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */

/*

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * Authors: Sébastien Deronne <sebastien.deronne@gmail.com>

 */

// This example is used to validate 802.11n MIMO.

//

// It ouputs plots of the throughput versus the distance

// for every HT MCS value and from 1 to 4 MIMO streams.

//

// The simulation assumes a single station in an infrastructure network:

//

//  STA     AP

//    *     *

//    |     |

//   n1     n2

//

// The user can choose whether UDP or TCP should be used and can configure

// some 802.11n parameters (frequency, channel width and guard interval).

#include "ns3/core-module.h"

#include "ns3/network-module.h"

#include "ns3/applications-module.h"

#include "ns3/wifi-module.h"

#include "ns3/mobility-module.h"

#include "ns3/ipv4-global-routing-helper.h"

#include "ns3/internet-module.h"

#include "ns3/gnuplot.h"

#include <fstream>

#include <vector>

#include <cmath>

using namespace ns3;

int main (int argc, char *argv[])

{

  std::ofstream file ("80211n-mimo-throughput.plt");

  std::vector <std::string> modes;

  modes.push_back ("HtMcs0");

  modes.push_back ("HtMcs1");

  modes.push_back ("HtMcs2");

  modes.push_back ("HtMcs3");

  modes.push_back ("HtMcs4");

  modes.push_back ("HtMcs5");

  modes.push_back ("HtMcs6");

  modes.push_back ("HtMcs7");

  modes.push_back ("HtMcs8");

  modes.push_back ("HtMcs9");

  modes.push_back ("HtMcs10");

  modes.push_back ("HtMcs11");

  modes.push_back ("HtMcs12");

  modes.push_back ("HtMcs13");

  modes.push_back ("HtMcs14");

  modes.push_back ("HtMcs15");

  modes.push_back ("HtMcs16");

  modes.push_back ("HtMcs17");

  modes.push_back ("HtMcs18");

  modes.push_back ("HtMcs19");

  modes.push_back ("HtMcs20");

  modes.push_back ("HtMcs21");

  modes.push_back ("HtMcs22");

  modes.push_back ("HtMcs23");

  modes.push_back ("HtMcs24");

  modes.push_back ("HtMcs25");

  modes.push_back ("HtMcs26");

  modes.push_back ("HtMcs27");

  modes.push_back ("HtMcs28");

  modes.push_back ("HtMcs29");

  modes.push_back ("HtMcs30");

  modes.push_back ("HtMcs31");

  bool udp = true;

  double simulationTime = 5; //seconds

  double frequency = 5.0; //whether 2.4 or 5.0 GHz

  double step = 5; //meters

  bool shortGuardInterval = false;

  bool channelBonding = false;

  CommandLine cmd;

  cmd.AddValue ("step", "Granularity of the results to be plotted in meters", step);

  cmd.AddValue ("channelBonding", "Enable/disable channel bonding (channel width = 20 MHz if false, channel width = 40 MHz if true)", channelBonding);

  cmd.AddValue ("shortGuardInterval", "Enable/disable short guard interval", shortGuardInterval);

  cmd.AddValue ("frequency", "Whether working in the 2.4 or 5.0 GHz band (other values gets rejected)", frequency);

  cmd.AddValue ("udp", "UDP if set to 1, TCP otherwise", udp);

  cmd.Parse (argc,argv);

  Gnuplot plot = Gnuplot ("80211n-mimo-throughput.eps");

  for (uint32_t i = 0; i < modes.size (); i++) //MCS

    {

      std::cout << modes[i] << std::endl;

      Gnuplot2dDataset dataset (modes[i]);

      for (int d = 0; d <= 100; ) //distance

        {

          std::cout << "Distance = " << d << "m: "<< std::endl;

          uint32_t payloadSize; //1500 byte IP packet

          if (udp)

            {

              payloadSize = 1472; //bytes

            }

          else

            {

              payloadSize = 1448; //bytes

              Config::SetDefault ("ns3::TcpSocket::SegmentSize", UintegerValue (payloadSize));

            }

          uint8_t nStreams = 1 + (i / 8); //number of MIMO streams

          NodeContainer wifiStaNode;

          wifiStaNode.Create (1);

          NodeContainer wifiApNode;

          wifiApNode.Create (1);

          YansWifiChannelHelper channel = YansWifiChannelHelper::Default ();

          YansWifiPhyHelper phy = YansWifiPhyHelper::Default ();

          phy.SetChannel (channel.Create ());

          // Set guard interval

          phy.Set ("ShortGuardEnabled", BooleanValue (shortGuardInterval));

          // Set MIMO capabilities

          phy.Set ("TxAntennas", UintegerValue (nStreams));

          phy.Set ("RxAntennas", UintegerValue (nStreams));

          WifiMacHelper mac;

          WifiHelper wifi;

          if (frequency == 5.0)

            {

              wifi.SetStandard (WIFI_PHY_STANDARD_80211n_5GHZ);

            }

          else if (frequency == 2.4)

            {

              wifi.SetStandard (WIFI_PHY_STANDARD_80211n_2_4GHZ);

              Config::SetDefault ("ns3::LogDistancePropagationLossModel::ReferenceLoss", DoubleValue (40.046));

            }

          else

            {

              std::cout<<"Wrong frequency value!"<<std::endl;

              return 0;

            }

          wifi.SetRemoteStationManager ("ns3::ConstantRateWifiManager","DataMode", StringValue (modes[i]),

                                        "ControlMode", StringValue (modes[i]));

          Ssid ssid = Ssid ("ns3-80211n");

          mac.SetType ("ns3::StaWifiMac",

                       "Ssid", SsidValue (ssid),

                       "ActiveProbing", BooleanValue (false));

          NetDeviceContainer staDevice;

          staDevice = wifi.Install (phy, mac, wifiStaNode);

          mac.SetType ("ns3::ApWifiMac",

                       "Ssid", SsidValue (ssid));

          NetDeviceContainer apDevice;

          apDevice = wifi.Install (phy, mac, wifiApNode);

          // Set channel width

          if (channelBonding)

            {

              Config::Set ("/NodeList/*/DeviceList/*/$ns3::WifiNetDevice/Phy/ChannelWidth", UintegerValue (40));

            }

          // mobility.

          MobilityHelper mobility;

          Ptr<ListPositionAllocator> positionAlloc = CreateObject<ListPositionAllocator> ();

          positionAlloc->Add (Vector (0.0, 0.0, 0.0));

          positionAlloc->Add (Vector (d, 0.0, 0.0));

          mobility.SetPositionAllocator (positionAlloc);

          mobility.SetMobilityModel ("ns3::ConstantPositionMobilityModel");

          mobility.Install (wifiApNode);

          mobility.Install (wifiStaNode);

          /* Internet stack*/

          InternetStackHelper stack;

          stack.Install (wifiApNode);

          stack.Install (wifiStaNode);

          Ipv4AddressHelper address;

          address.SetBase ("192.168.1.0", "255.255.255.0");

          Ipv4InterfaceContainer staNodeInterface;

          Ipv4InterfaceContainer apNodeInterface;

          staNodeInterface = address.Assign (staDevice);

          apNodeInterface = address.Assign (apDevice);

          /* Setting applications */

          ApplicationContainer serverApp, sinkApp;

          if (udp)

            {

              //UDP flow

              UdpServerHelper myServer (9);

              serverApp = myServer.Install (wifiStaNode.Get (0));

              serverApp.Start (Seconds (0.0));

              serverApp.Stop (Seconds (simulationTime + 1));

              UdpClientHelper myClient (staNodeInterface.GetAddress (0), 9);

              myClient.SetAttribute ("MaxPackets", UintegerValue (4294967295u));

              myClient.SetAttribute ("Interval", TimeValue (Time ("0.00001"))); //packets/s

              myClient.SetAttribute ("PacketSize", UintegerValue (payloadSize));

              ApplicationContainer clientApp = myClient.Install (wifiApNode.Get (0));

              clientApp.Start (Seconds (1.0));

              clientApp.Stop (Seconds (simulationTime + 1));

            }

          else

            {

              //TCP flow

              uint16_t port = 50000;

              Address apLocalAddress (InetSocketAddress (Ipv4Address::GetAny (), port));

              PacketSinkHelper packetSinkHelper ("ns3::TcpSocketFactory", apLocalAddress);

              sinkApp = packetSinkHelper.Install (wifiStaNode.Get (0));

              sinkApp.Start (Seconds (0.0));

              sinkApp.Stop (Seconds (simulationTime + 1));

              OnOffHelper onoff ("ns3::TcpSocketFactory",Ipv4Address::GetAny ());

              onoff.SetAttribute ("OnTime",  StringValue ("ns3::ConstantRandomVariable[Constant=1]"));

              onoff.SetAttribute ("OffTime", StringValue ("ns3::ConstantRandomVariable[Constant=0]"));

              onoff.SetAttribute ("PacketSize", UintegerValue (payloadSize));

              onoff.SetAttribute ("DataRate", DataRateValue (1000000000)); //bit/s

              ApplicationContainer apps;

              AddressValue remoteAddress (InetSocketAddress (staNodeInterface.GetAddress (0), port));

              onoff.SetAttribute ("Remote", remoteAddress);

              apps.Add (onoff.Install (wifiApNode.Get (0)));

              apps.Start (Seconds (1.0));

              apps.Stop (Seconds (simulationTime + 1));

            }

          Ipv4GlobalRoutingHelper::PopulateRoutingTables ();

          Simulator::Stop (Seconds (simulationTime + 1));

          Simulator::Run ();

          Simulator::Destroy ();

          double throughput = 0;

          if (udp)

            {

              //UDP

              uint32_t totalPacketsThrough = DynamicCast<UdpServer> (serverApp.Get (0))->GetReceived ();

              throughput = totalPacketsThrough * payloadSize * 8 / (simulationTime * 1000000.0); //Mbit/s

            }

          else

            {

              //TCP

              uint32_t totalPacketsThrough = DynamicCast<PacketSink> (sinkApp.Get (0))->GetTotalRx ();

              throughput = totalPacketsThrough * 8 / (simulationTime * 1000000.0); //Mbit/s

            }

          dataset.Add (d, throughput);

          std::cout << throughput << " Mbit/s" <<std::endl;

          d += step;

        }

      plot.AddDataset (dataset);

    }

  plot.SetTerminal ("postscript eps color enh \"Times-BoldItalic\"");

  plot.SetLegend ("Distance (Meters)", "Throughput (Mbit/s)");

  plot.SetExtra  ("set xrange [0:100]\n\

set yrange [0:600]\n\

set ytics 0,50,600\n\

set style line 1 dashtype 1 linewidth 5\n\

set style line 2 dashtype 1 linewidth 5\n\

set style line 3 dashtype 1 linewidth 5\n\

set style line 4 dashtype 1 linewidth 5\n\

set style line 5 dashtype 1 linewidth 5\n\

set style line 6 dashtype 1 linewidth 5\n\

set style line 7 dashtype 1 linewidth 5\n\

set style line 8 dashtype 1 linewidth 5\n\

set style line 9 dashtype 2 linewidth 5\n\

set style line 10 dashtype 2 linewidth 5\n\

set style line 11 dashtype 2 linewidth 5\n\

set style line 12 dashtype 2 linewidth 5\n\

set style line 13 dashtype 2 linewidth 5\n\

set style line 14 dashtype 2 linewidth 5\n\

set style line 15 dashtype 2 linewidth 5\n\

set style line 16 dashtype 2 linewidth 5\n\

set style line 17 dashtype 3 linewidth 5\n\

set style line 18 dashtype 3 linewidth 5\n\

set style line 19 dashtype 3 linewidth 5\n\

set style line 20 dashtype 3 linewidth 5\n\

set style line 21 dashtype 3 linewidth 5\n\

set style line 22 dashtype 3 linewidth 5\n\

set style line 23 dashtype 3 linewidth 5\n\

set style line 24 dashtype 3 linewidth 5\n\

set style line 25 dashtype 4 linewidth 5\n\

set style line 26 dashtype 4 linewidth 5\n\

set style line 27 dashtype 4 linewidth 5\n\

set style line 28 dashtype 4 linewidth 5\n\

set style line 29 dashtype 4 linewidth 5\n\

set style line 30 dashtype 4 linewidth 5\n\

set style line 31 dashtype 4 linewidth 5\n\

set style line 32 dashtype 4 linewidth 5\n\

set style increment user"                                                                                                                                                                                                                                                                                                                                   );

  plot.GenerateOutput (file);

  file.close ();

  return 0;

}

    obj = bld.create_ns3_program('80211n-mimo', ['core','internet', 'mobility', 'wifi', 'applications', 'propagation'])

    obj.source = '80211n-mimo.cc'

In order to enable 802.11n/ac MIMO, the number of Rx antennas as well as the number of Tx antennas need to be configured.

For example, this code enables 2x2 MIMO::

 wifiPhyHelper.Set ("TxAntennas", UintegerValue (2));

 wifiPhyHelper.Set ("RxAntennas", UintegerValue (2));