wifi-simple-infra.cc

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/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2009 The Boeing Company
 *
 * 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
 *
 */
 
// This script configures two nodes on an 802.11b physical layer, with
// 802.11b NICs in infrastructure mode, and by default, the station sends
// one packet of 1000 (application) bytes to the access point.  Unlike
// the default physical layer configuration in which the path loss increases
// (and the received signal strength decreases) as the distance between the
// nodes increases, this example uses an artificial path loss model that
// allows the configuration of the received signal strength (RSS) regardless
// of other transmitter parameters (such as transmit power) or distance.
// Therefore, changing position of the nodes has no effect.
//
// There are a number of command-line options available to control
// the default behavior.  The list of available command-line options
// can be listed with the following command:
// ./ns3 run "wifi-simple-infra --help"
// Additional command-line options are available via the generic attribute
// configuration system.
//
// For instance, for the default configuration, the physical layer will
// stop successfully receiving packets when rss drops to -82 dBm or below.
// To see this effect, try running:
//
// ./ns3 run "wifi-simple-infra --rss=-80 --numPackets=20"
// ./ns3 run "wifi-simple-infra --rss=-81 --numPackets=20"
// ./ns3 run "wifi-simple-infra --rss=-82 --numPackets=20"
//
// The last command (and any RSS value lower than this) results in no
// packets received.  This is due to the preamble detection model that
// dominates the reception performance.  By default, the
// ThresholdPreambleDetectionModel is added to all WifiPhy objects, and this
// model prevents reception unless the incoming signal has a RSS above its
// 'MinimumRssi' value (default of -82 dBm) and has a SNR above the 
// 'Threshold' value (default of 4).
//
// If we relax these values, we can instead observe that signal reception
// due to the 802.11b error model alone is much lower.  For instance,
// setting the MinimumRssi to -101 (around the thermal noise floor).
// and the SNR Threshold to -10 dB, shows that the DsssErrorRateModel can
// successfully decode at RSS values of -97 or -98 dBm.
//
// ./ns3 run "wifi-simple-infra --rss=-97 --numPackets=20 --ns3::ThresholdPreambleDetectionModel::Threshold=-10 --ns3::ThresholdPreambleDetectionModel::MinimumRssi=-101"
// ./ns3 run "wifi-simple-infra --rss=-98 --numPackets=20 --ns3::ThresholdPreambleDetectionModel::Threshold=-10 --ns3::ThresholdPreambleDetectionModel::MinimumRssi=-101"
// ./ns3 run "wifi-simple-infra --rss=-99 --numPackets=20 --ns3::ThresholdPreambleDetectionModel::Threshold=-10 --ns3::ThresholdPreambleDetectionModel::MinimumRssi=-101"
 
//
// Note that all ns-3 attributes (not just the ones exposed in the below
// script) can be changed at command line; see the documentation.
//
// This script can also be helpful to put the Wifi layer into verbose
// logging mode; this command will turn on all wifi logging:
//
// ./ns3 run "wifi-simple-infra --verbose=1"
//
// When you are done, you will notice two pcap trace files in your directory.
// If you have tcpdump installed, you can try this:
//
// tcpdump -r wifi-simple-infra-0-0.pcap -nn -tt
//
 
#include "ns3/command-line.h"
#include "ns3/config.h"
#include "ns3/double.h"
#include "ns3/string.h"
#include "ns3/log.h"
#include "ns3/yans-wifi-helper.h"
#include "ns3/ssid.h"
#include "ns3/mobility-helper.h"
#include "ns3/ipv4-address-helper.h"
#include "ns3/yans-wifi-channel.h"
#include "ns3/mobility-model.h"
#include "ns3/internet-stack-helper.h"
 
using namespace ns3;
 
NS_LOG_COMPONENT_DEFINE ("WifiSimpleInfra");
 
void ReceivePacket (Ptr<Socket> socket)
{
  while (socket->Recv ())
    {
      std::cout << "Received one packet!" << std::endl;
    }
}
 
static void GenerateTraffic (Ptr<Socket> socket, uint32_t pktSize,
                             uint32_t pktCount, Time pktInterval )
{
  if (pktCount > 0)
    {
      NS_LOG_INFO ("Generating one packet of size " << pktSize);
      socket->Send (Create<Packet> (pktSize));
      Simulator::Schedule (pktInterval, &GenerateTraffic,
                           socket, pktSize, pktCount - 1, pktInterval);
    }
  else
    {
      socket->Close ();
    }
}
 
int main (int argc, char *argv[])
{
  std::string phyMode ("DsssRate1Mbps");
  double rss = -80;  // -dBm
  uint32_t packetSize = 1000; // bytes
  uint32_t numPackets = 1;
  Time interval = Seconds (1.0);
  bool verbose = false;
 
  CommandLine cmd (__FILE__);
  cmd.AddValue ("phyMode", "Wifi Phy mode", phyMode);
  cmd.AddValue ("rss", "received signal strength", rss);
  cmd.AddValue ("packetSize", "size of application packet sent", packetSize);
  cmd.AddValue ("numPackets", "number of packets generated", numPackets);
  cmd.AddValue ("interval", "interval between packets", interval);
  cmd.AddValue ("verbose", "turn on all WifiNetDevice log components", verbose);
  cmd.Parse (argc, argv);
 
  // Fix non-unicast data rate to be the same as that of unicast
  Config::SetDefault ("ns3::WifiRemoteStationManager::NonUnicastMode",
                      StringValue (phyMode));
 
  NodeContainer c;
  c.Create (2);
 
  // The below set of helpers will help us to put together the wifi NICs we want
  WifiHelper wifi;
  if (verbose)
    {
      wifi.EnableLogComponents ();  // Turn on all Wifi logging
    }
  wifi.SetStandard (WIFI_STANDARD_80211b);
 
  YansWifiPhyHelper wifiPhy;
  // This is one parameter that matters when using FixedRssLossModel
  // set it to zero; otherwise, gain will be added
  wifiPhy.Set ("RxGain", DoubleValue (0) );
  // ns-3 supports RadioTap and Prism tracing extensions for 802.11b
  wifiPhy.SetPcapDataLinkType (WifiPhyHelper::DLT_IEEE802_11_RADIO);
 
  YansWifiChannelHelper wifiChannel;
  wifiChannel.SetPropagationDelay ("ns3::ConstantSpeedPropagationDelayModel");
  // The below FixedRssLossModel will cause the rss to be fixed regardless
  // of the distance between the two stations, and the transmit power
  wifiChannel.AddPropagationLoss ("ns3::FixedRssLossModel","Rss",DoubleValue (rss));
  wifiPhy.SetChannel (wifiChannel.Create ());
 
  // Add a mac and disable rate control
  WifiMacHelper wifiMac;
  wifi.SetRemoteStationManager ("ns3::ConstantRateWifiManager",
                                "DataMode", StringValue (phyMode),
                                "ControlMode", StringValue (phyMode));
 
  // Setup the rest of the MAC
  Ssid ssid = Ssid ("wifi-default");
  // setup STA 
  wifiMac.SetType ("ns3::StaWifiMac",
                   "Ssid", SsidValue (ssid));
  NetDeviceContainer staDevice = wifi.Install (wifiPhy, wifiMac, c.Get (0));
  NetDeviceContainer devices = staDevice;
  // setup AP
  wifiMac.SetType ("ns3::ApWifiMac",
                   "Ssid", SsidValue (ssid));
  NetDeviceContainer apDevice = wifi.Install (wifiPhy, wifiMac, c.Get (1));
  devices.Add (apDevice);
 
  // Note that with FixedRssLossModel, the positions below are not
  // used for received signal strength.
  MobilityHelper mobility;
  Ptr<ListPositionAllocator> positionAlloc = CreateObject<ListPositionAllocator> ();
  positionAlloc->Add (Vector (0.0, 0.0, 0.0));
  positionAlloc->Add (Vector (5.0, 0.0, 0.0));
  mobility.SetPositionAllocator (positionAlloc);
  mobility.SetMobilityModel ("ns3::ConstantPositionMobilityModel");
  mobility.Install (c);
 
  InternetStackHelper internet;
  internet.Install (c);
 
  Ipv4AddressHelper ipv4;
  ipv4.SetBase ("10.1.1.0", "255.255.255.0");
  Ipv4InterfaceContainer i = ipv4.Assign (devices);
 
  TypeId tid = TypeId::LookupByName ("ns3::UdpSocketFactory");
  Ptr<Socket> recvSink = Socket::CreateSocket (c.Get (0), tid);
  InetSocketAddress local = InetSocketAddress (Ipv4Address::GetAny (), 80);
  recvSink->Bind (local);
  recvSink->SetRecvCallback (MakeCallback (&ReceivePacket));
 
  Ptr<Socket> source = Socket::CreateSocket (c.Get (1), tid);
  InetSocketAddress remote = InetSocketAddress (Ipv4Address ("255.255.255.255"), 80);
  source->SetAllowBroadcast (true);
  source->Connect (remote);
 
  // Tracing
  wifiPhy.EnablePcap ("wifi-simple-infra", devices);
 
  // Output what we are doing
  std::cout << "Testing " << numPackets  << " packets sent with receiver rss " << rss << std::endl;
 
  Simulator::ScheduleWithContext (source->GetNode ()->GetId (),
                                  Seconds (1.0), &GenerateTraffic,
                                  source, packetSize, numPackets, interval);
 
  Simulator::Stop (Seconds (30.0));
  Simulator::Run ();
  Simulator::Destroy ();
 
  return 0;
}