wifi-he-network.cc

Go to the documentation of this file.

/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2016 SEBASTIEN DERONNE
 *
 * 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
 *
 * Author: Sebastien Deronne <sebastien.deronne@gmail.com>
 */
 
#include "ns3/command-line.h"
#include "ns3/config.h"
#include "ns3/uinteger.h"
#include "ns3/boolean.h"
#include "ns3/double.h"
#include "ns3/string.h"
#include "ns3/enum.h"
#include "ns3/log.h"
#include "ns3/yans-wifi-helper.h"
#include "ns3/spectrum-wifi-helper.h"
#include "ns3/ssid.h"
#include "ns3/mobility-helper.h"
#include "ns3/internet-stack-helper.h"
#include "ns3/ipv4-address-helper.h"
#include "ns3/udp-client-server-helper.h"
#include "ns3/packet-sink-helper.h"
#include "ns3/on-off-helper.h"
#include "ns3/ipv4-global-routing-helper.h"
#include "ns3/packet-sink.h"
#include "ns3/yans-wifi-channel.h"
#include "ns3/multi-model-spectrum-channel.h"
#include "ns3/wifi-acknowledgment.h"
#include "ns3/rng-seed-manager.h"
 
// This is a simple example in order to show how to configure an IEEE 802.11ax Wi-Fi network.
//
// It outputs the UDP or TCP goodput for every HE MCS value, which depends on the MCS value (0 to 11),
// the channel width (20, 40, 80 or 160 MHz) and the guard interval (800ns, 1600ns or 3200ns).
// The PHY bitrate is constant over all the simulation run. The user can also specify the distance between
// the access point and the station: the larger the distance the smaller the goodput.
//
// The simulation assumes a configurable number of stations in an infrastructure network:
//
//  STA     AP
//    *     *
//    |     |
//   n1     n2
//
// Packets in this simulation belong to BestEffort Access Class (AC_BE).
// By selecting an acknowledgment sequence for DL MU PPDUs, it is possible to aggregate a
// Round Robin scheduler to the AP, so that DL MU PPDUs are sent by the AP via DL OFDMA.
 
using namespace ns3;
 
NS_LOG_COMPONENT_DEFINE ("he-wifi-network");
 
int main (int argc, char *argv[])
{
  bool udp {true};
  bool useRts {false};
  bool useExtendedBlockAck {false};
  double simulationTime {10}; //seconds
  double distance {1.0}; //meters
  double frequency {5}; //whether 2.4, 5 or 6 GHz
  std::size_t nStations {1};
  std::string dlAckSeqType {"NO-OFDMA"};
  int mcs {-1}; // -1 indicates an unset value
  uint32_t payloadSize = 700; // must fit in the max TX duration when transmitting at MCS 0 over an RU of 26 tones
  std::string phyModel {"Yans"};
  double minExpectedThroughput {0};
  double maxExpectedThroughput {0};
 
  CommandLine cmd (__FILE__);
  cmd.AddValue ("frequency", "Whether working in the 2.4, 5 or 6 GHz band (other values gets rejected)", frequency);
  cmd.AddValue ("distance", "Distance in meters between the station and the access point", distance);
  cmd.AddValue ("simulationTime", "Simulation time in seconds", simulationTime);
  cmd.AddValue ("udp", "UDP if set to 1, TCP otherwise", udp);
  cmd.AddValue ("useRts", "Enable/disable RTS/CTS", useRts);
  cmd.AddValue ("useExtendedBlockAck", "Enable/disable use of extended BACK", useExtendedBlockAck);
  cmd.AddValue ("nStations", "Number of non-AP HE stations", nStations);
  cmd.AddValue ("dlAckType", "Ack sequence type for DL OFDMA (NO-OFDMA, ACK-SU-FORMAT, MU-BAR, AGGR-MU-BAR)",
                dlAckSeqType);
  cmd.AddValue ("mcs", "if set, limit testing to a specific MCS (0-11)", mcs);
  cmd.AddValue ("payloadSize", "The application payload size in bytes", payloadSize);
  cmd.AddValue ("phyModel", "PHY model to use when OFDMA is disabled (Yans or Spectrum). If OFDMA is enabled then Spectrum is automatically selected", phyModel);
  cmd.AddValue ("minExpectedThroughput", "if set, simulation fails if the lowest throughput is below this value", minExpectedThroughput);
  cmd.AddValue ("maxExpectedThroughput", "if set, simulation fails if the highest throughput is above this value", maxExpectedThroughput);
  cmd.Parse (argc,argv);
 
  if (useRts)
    {
      Config::SetDefault ("ns3::WifiRemoteStationManager::RtsCtsThreshold", StringValue ("0"));
    }
 
  if (dlAckSeqType == "ACK-SU-FORMAT")
    {
      Config::SetDefault ("ns3::WifiDefaultAckManager::DlMuAckSequenceType",
                          EnumValue (WifiAcknowledgment::DL_MU_BAR_BA_SEQUENCE));
    }
  else if (dlAckSeqType == "MU-BAR")
    {
      Config::SetDefault ("ns3::WifiDefaultAckManager::DlMuAckSequenceType",
                          EnumValue (WifiAcknowledgment::DL_MU_TF_MU_BAR));
    }
  else if (dlAckSeqType == "AGGR-MU-BAR")
    {
      Config::SetDefault ("ns3::WifiDefaultAckManager::DlMuAckSequenceType",
                          EnumValue (WifiAcknowledgment::DL_MU_AGGREGATE_TF));
    }
  else if (dlAckSeqType != "NO-OFDMA")
    {
      NS_ABORT_MSG ("Invalid DL ack sequence type (must be NO-OFDMA, ACK-SU-FORMAT, MU-BAR or AGGR-MU-BAR)");
    }
 
  if (phyModel != "Yans" && phyModel != "Spectrum")
    {
      NS_ABORT_MSG ("Invalid PHY model (must be Yans or Spectrum)");
    }
  if (dlAckSeqType != "NO-OFDMA")
    {
      // SpectrumWifiPhy is required for OFDMA
      phyModel = "Spectrum";
    }
 
  double prevThroughput [12];
  for (uint32_t l = 0; l < 12; l++)
    {
      prevThroughput[l] = 0;
    }
  std::cout << "MCS value" << "\t\t" << "Channel width" << "\t\t" << "GI" << "\t\t\t" << "Throughput" << '\n';
  int minMcs = 0;
  int maxMcs = 11;
  if (mcs >= 0 && mcs <= 11)
    {
      minMcs = mcs;
      maxMcs = mcs;
    }
  for (int mcs = minMcs; mcs <= maxMcs; mcs++)
    {
      uint8_t index = 0;
      double previous = 0;
      uint8_t maxChannelWidth = frequency == 2.4 ? 40 : 160;
      for (int channelWidth = 20; channelWidth <= maxChannelWidth; ) //MHz
        {
          for (int gi = 3200; gi >= 800; ) //Nanoseconds
            {
              if (!udp)
                {
                  Config::SetDefault ("ns3::TcpSocket::SegmentSize", UintegerValue (payloadSize));
                }
 
              NodeContainer wifiStaNodes;
              wifiStaNodes.Create (nStations);
              NodeContainer wifiApNode;
              wifiApNode.Create (1);
 
              NetDeviceContainer apDevice, staDevices;
              WifiMacHelper mac;
              WifiHelper wifi;
 
              if (frequency == 6)
                {
                  wifi.SetStandard (WIFI_STANDARD_80211ax_6GHZ);
                  Config::SetDefault ("ns3::LogDistancePropagationLossModel::ReferenceLoss", DoubleValue (48));
                }
              else if (frequency == 5)
                {
                  wifi.SetStandard (WIFI_STANDARD_80211ax_5GHZ);
                }
              else if (frequency == 2.4)
                {
                  wifi.SetStandard (WIFI_STANDARD_80211ax_2_4GHZ);
                  Config::SetDefault ("ns3::LogDistancePropagationLossModel::ReferenceLoss", DoubleValue (40));
                }
              else
                {
                  std::cout << "Wrong frequency value!" << std::endl;
                  return 0;
                }
 
              std::ostringstream oss;
              oss << "HeMcs" << mcs;
              wifi.SetRemoteStationManager ("ns3::ConstantRateWifiManager","DataMode", StringValue (oss.str ()),
                                            "ControlMode", StringValue (oss.str ()));
 
              Ssid ssid = Ssid ("ns3-80211ax");
 
              if (phyModel == "Spectrum")
                {
                  /*
                  * SingleModelSpectrumChannel cannot be used with 802.11ax because two
                  * spectrum models are required: one with 78.125 kHz bands for HE PPDUs
                  * and one with 312.5 kHz bands for, e.g., non-HT PPDUs (for more details,
                  * see issue #408 (CLOSED))
                  */
                  Ptr<MultiModelSpectrumChannel> spectrumChannel = CreateObject<MultiModelSpectrumChannel> ();
                  SpectrumWifiPhyHelper phy;
                  phy.SetPcapDataLinkType (WifiPhyHelper::DLT_IEEE802_11_RADIO);
                  phy.SetChannel (spectrumChannel);
 
                  mac.SetType ("ns3::StaWifiMac",
                              "Ssid", SsidValue (ssid));
                  phy.Set ("ChannelWidth", UintegerValue (channelWidth));
                  staDevices = wifi.Install (phy, mac, wifiStaNodes);
 
                  if (dlAckSeqType != "NO-OFDMA")
                    {
                      mac.SetMultiUserScheduler ("ns3::RrMultiUserScheduler",
                                                "EnableUlOfdma", BooleanValue (false),
                                                "EnableBsrp", BooleanValue (false));
                    }
                  mac.SetType ("ns3::ApWifiMac",
                              "EnableBeaconJitter", BooleanValue (false),
                              "Ssid", SsidValue (ssid));
                  phy.Set ("ChannelWidth", UintegerValue (channelWidth));
                  apDevice = wifi.Install (phy, mac, wifiApNode);
                }
              else
                {
                  YansWifiChannelHelper channel = YansWifiChannelHelper::Default ();
                  YansWifiPhyHelper phy;
                  phy.SetPcapDataLinkType (WifiPhyHelper::DLT_IEEE802_11_RADIO);
                  phy.SetChannel (channel.Create ());
 
                  mac.SetType ("ns3::StaWifiMac",
                              "Ssid", SsidValue (ssid));
                  phy.Set ("ChannelWidth", UintegerValue (channelWidth));
                  staDevices = wifi.Install (phy, mac, wifiStaNodes);
 
                  mac.SetType ("ns3::ApWifiMac",
                              "EnableBeaconJitter", BooleanValue (false),
                              "Ssid", SsidValue (ssid));
                  phy.Set ("ChannelWidth", UintegerValue (channelWidth));
                  apDevice = wifi.Install (phy, mac, wifiApNode);
                }
 
              RngSeedManager::SetSeed (1);
              RngSeedManager::SetRun (1);
              int64_t streamNumber = 100;
              streamNumber += wifi.AssignStreams (apDevice, streamNumber);
              streamNumber += wifi.AssignStreams (staDevices, streamNumber);
 
              // Set guard interval and MPDU buffer size
              Config::Set ("/NodeList/*/DeviceList/*/$ns3::WifiNetDevice/HeConfiguration/GuardInterval", TimeValue (NanoSeconds (gi)));
              Config::Set ("/NodeList/*/DeviceList/*/$ns3::WifiNetDevice/HeConfiguration/MpduBufferSize", UintegerValue (useExtendedBlockAck ? 256 : 64));
 
              // mobility.
              MobilityHelper mobility;
              Ptr<ListPositionAllocator> positionAlloc = CreateObject<ListPositionAllocator> ();
 
              positionAlloc->Add (Vector (0.0, 0.0, 0.0));
              positionAlloc->Add (Vector (distance, 0.0, 0.0));
              mobility.SetPositionAllocator (positionAlloc);
 
              mobility.SetMobilityModel ("ns3::ConstantPositionMobilityModel");
 
              mobility.Install (wifiApNode);
              mobility.Install (wifiStaNodes);
 
              /* Internet stack*/
              InternetStackHelper stack;
              stack.Install (wifiApNode);
              stack.Install (wifiStaNodes);
 
              Ipv4AddressHelper address;
              address.SetBase ("192.168.1.0", "255.255.255.0");
              Ipv4InterfaceContainer staNodeInterfaces;
              Ipv4InterfaceContainer apNodeInterface;
 
              staNodeInterfaces = address.Assign (staDevices);
              apNodeInterface = address.Assign (apDevice);
 
              /* Setting applications */
              ApplicationContainer serverApp;
              if (udp)
                {
                  //UDP flow
                  uint16_t port = 9;
                  UdpServerHelper server (port);
                  serverApp = server.Install (wifiStaNodes);
                  serverApp.Start (Seconds (0.0));
                  serverApp.Stop (Seconds (simulationTime + 1));
 
                  for (std::size_t i = 0; i < nStations; i++)
                    {
                      UdpClientHelper client (staNodeInterfaces.GetAddress (i), port);
                      client.SetAttribute ("MaxPackets", UintegerValue (4294967295u));
                      client.SetAttribute ("Interval", TimeValue (Time ("0.00001"))); //packets/s
                      client.SetAttribute ("PacketSize", UintegerValue (payloadSize));
                      ApplicationContainer clientApp = client.Install (wifiApNode.Get (0));
                      clientApp.Start (Seconds (1.0));
                      clientApp.Stop (Seconds (simulationTime + 1));
                    }
                }
              else
                {
                  //TCP flow
                  uint16_t port = 50000;
                  Address localAddress (InetSocketAddress (Ipv4Address::GetAny (), port));
                  PacketSinkHelper packetSinkHelper ("ns3::TcpSocketFactory", localAddress);
                  serverApp = packetSinkHelper.Install (wifiStaNodes);
                  serverApp.Start (Seconds (0.0));
                  serverApp.Stop (Seconds (simulationTime + 1));
 
                  for (std::size_t i = 0; i < nStations; i++)
                    {
                      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
                      AddressValue remoteAddress (InetSocketAddress (staNodeInterfaces.GetAddress (i), port));
                      onoff.SetAttribute ("Remote", remoteAddress);
                      ApplicationContainer clientApp = onoff.Install (wifiApNode.Get (0));
                      clientApp.Start (Seconds (1.0));
                      clientApp.Stop (Seconds (simulationTime + 1));
                    }
                }
 
              Simulator::Schedule (Seconds (0), &Ipv4GlobalRoutingHelper::PopulateRoutingTables);
 
              Simulator::Stop (Seconds (simulationTime + 1));
              Simulator::Run ();
 
              // When multiple stations are used, there are chances that association requests collide
              // and hence the throughput may be lower than expected. Therefore, we relax the check
              // that the throughput cannot decrease by introducing a scaling factor (or tolerance)
              double tolerance = 0.10;
              uint64_t rxBytes = 0;
              if (udp)
                {
                  for (uint32_t i = 0; i < serverApp.GetN (); i++)
                    {
                      rxBytes += payloadSize * DynamicCast<UdpServer> (serverApp.Get (i))->GetReceived ();
                    }
                }
              else
                {
                  for (uint32_t i = 0; i < serverApp.GetN (); i++)
                    {
                      rxBytes += DynamicCast<PacketSink> (serverApp.Get (i))->GetTotalRx ();
                    }
                }
              double throughput = (rxBytes * 8) / (simulationTime * 1000000.0); //Mbit/s
 
              Simulator::Destroy ();
 
              std::cout << mcs << "\t\t\t" << channelWidth << " MHz\t\t\t" << gi << " ns\t\t\t" << throughput << " Mbit/s" << std::endl;
 
              //test first element
              if (mcs == 0 && channelWidth == 20 && gi == 3200)
                {
                  if (throughput * (1 + tolerance) < minExpectedThroughput)
                    {
                      NS_LOG_ERROR ("Obtained throughput " << throughput << " is not expected!");
                      exit (1);
                    }
                }
              //test last element
              if (mcs == 11 && channelWidth == 160 && gi == 800)
                {
                  if (maxExpectedThroughput > 0 && throughput > maxExpectedThroughput * (1 + tolerance))
                    {
                      NS_LOG_ERROR ("Obtained throughput " << throughput << " is not expected!");
                      exit (1);
                    }
                }
              //test previous throughput is smaller (for the same mcs)
              if (throughput * (1 + tolerance) > previous)
                {
                  previous = throughput;
                }
              else
                {
                  NS_LOG_ERROR ("Obtained throughput " << throughput << " is not expected!");
                  exit (1);
                }
              //test previous throughput is smaller (for the same channel width and GI)
              if (throughput * (1 + tolerance) > prevThroughput [index])
                {
                  prevThroughput [index] = throughput;
                }
              else
                {
                  NS_LOG_ERROR ("Obtained throughput " << throughput << " is not expected!");
                  exit (1);
                }
              index++;
              gi /= 2;
            }
          channelWidth *= 2;
        }
    }
  return 0;
}