ns3 模擬無線網絡通信

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#include "ns3/core-module.h"
#include "ns3/point-to-point-module.h"
#include "ns3/network-module.h"
#include "ns3/applications-module.h"
#include "ns3/wifi-module.h"
#include "ns3/mobility-module.h"
#include "ns3/csma-module.h"
#include "ns3/internet-module.h"


using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("ThirdScriptExample");

int
main (int argc, char *argv[])
{
  Time::SetResolution (Time::NS);

  bool verbose = true;
  uint32_t nWifi = 3; //設置 無線站點個數
  bool tracing = false;

  CommandLine cmd;
  cmd.AddValue ("nWifi", "Number of wifi STA devices", nWifi);
  cmd.AddValue ("verbose", "Tell echo applications to log if true", verbose);  
  //用命令行修改參數
  cmd.Parse (argc,argv);


  if (nWifi > 250)
    {
      std::cout << "Too many wifi or csma nodes, no more than 250 each." << std::endl;
      return 1;
    }

  if (verbose)
    {
      LogComponentEnable ("UdpEchoClientApplication", LOG_LEVEL_ALL);
      LogComponentEnable ("UdpEchoServerApplication", LOG_LEVEL_ALL);
    }


  NodeContainer wifiStaNodes;
  wifiStaNodes.Create (nWifi);  //創建無線站點STA的節點
  NodeContainer wifiApNode;
  wifiApNode.Create(1);   //創建一個AP節點
  
  YansWifiChannelHelper channel = YansWifiChannelHelper::Default ();   //使用默認的信道模型
  YansWifiPhyHelper phy = YansWifiPhyHelper::Default ();  //使用默認的PHY模型
  phy.SetChannel (channel.Create ());  //創建通道對象並把他關聯到物理層對象管理器

  WifiHelper wifi;
  wifi.SetRemoteStationManager ("ns3::AarfWifiManager");  //設置wifi助手用AARF速率控制算法  

  //配置Mac類型以及基礎設置SSID
  WifiMacHelper mac;  
  Ssid ssid = Ssid ("ns-3-aqiao");  //設置SSID的名字為ns-3-aqiao
  mac.SetType ("ns3::StaWifiMac",    //指定mac層指定為ns3::StaWifiMac
               "Ssid", SsidValue (ssid),   //設置默認AP是ssid對象
               "ActiveProbing", BooleanValue (false));  //設置不會發出主動探測AP的指令，默認AP是ssid

  NetDeviceContainer staDevices;
  staDevices = wifi.Install (phy, mac, wifiStaNodes);  //在MAC層和PHY層用以前安裝方法來創建這些無線設備

  mac.SetType ("ns3::ApWifiMac",   //指定為AP
               "Ssid", SsidValue (ssid));    

  NetDeviceContainer apDevices;
  apDevices = wifi.Install (phy, mac, wifiApNode);   //一起共享PHY層的屬性

  // 加入移動模型，讓STA可以移動，AP固定
  MobilityHelper mobility;  

  mobility.SetPositionAllocator ("ns3::GridPositionAllocator",
                                 "MinX", DoubleValue (0.0),
                                 "MinY", DoubleValue (0.0),
                                 "DeltaX", DoubleValue (5.0),
                                 "DeltaY", DoubleValue (10.0),
                                 "GridWidth", UintegerValue (3),
                                 "LayoutType", StringValue ("RowFirst"));
  //設置初始時，節點的擺放位置
   
  mobility.SetMobilityModel ("ns3::RandomWalk2dMobilityModel",   //設置移動模式為"ns3::RandomWalk2dMobilityModel"，隨機移動
                             "Bounds", RectangleValue (Rectangle (-50, 50, -50, 50)));   //移動范圍
  mobility.Install (wifiStaNodes);
  
  mobility.SetMobilityModel ("ns3::ConstantPositionMobilityModel");  //設置AP的不能夠移動的，"ns3::ConstantPositionMobilityModel"
  mobility.Install (wifiApNode);

  InternetStackHelper stack;
  stack.Install (wifiApNode);
  stack.Install (wifiStaNodes);   //安裝協議棧

  Ipv4AddressHelper address;

  address.SetBase ("10.1.3.0", "255.255.255.0");
  Ipv4InterfaceContainer wifiInterfaces;
  wifiInterfaces=address.Assign (staDevices);
  address.Assign (apDevices);                 //地址分配

  //安裝暗涌程序，使用UDP，與之前的UDP的使用方法一致
  UdpEchoServerHelper echoServer (9);

  ApplicationContainer serverApps = echoServer.Install (wifiStaNodes.Get (0));
  serverApps.Start (Seconds (1.0));
  serverApps.Stop (Seconds (10.0));

  UdpEchoClientHelper echoClient (wifiInterfaces.GetAddress (0), 9);
  echoClient.SetAttribute ("MaxPackets", UintegerValue (5));
  echoClient.SetAttribute ("Interval", TimeValue (Seconds (1.0)));
  echoClient.SetAttribute ("PacketSize", UintegerValue (1024));

  ApplicationContainer clientApps =
    echoClient.Install (wifiStaNodes.Get (nWifi - 1));
  clientApps.Start (Seconds (2.0));
  clientApps.Stop (Seconds (10.0));

  Ipv4GlobalRoutingHelper::PopulateRoutingTables ();

  Simulator::Stop (Seconds (10.0));

  phy.EnablePcap ("wifiwifi", apDevices.Get (0));

  Simulator::Run ();
  Simulator::Destroy ();
  return 0;
}

 輸出結果

發現與之前的UDP傳送成功。

 

利用該命令可以，可以查看代碼中更詳細pcap內容

這個部分主要完成的是各個STA接入AP的控制信息，由於無線網絡中，並不能確定信息是否收發成功，所以一定要接受到一個ACK，表示數據發送成功

 

接下來是ARP協議通過 IP地址去得到對方的MAC地址，以便於后面可以實現基於mac層的802.11數據傳輸

 

已經得到了MAC地址后，后面就不需要再進行ARP的詢問了。

 

通過VIS得到的可視化結果