NS-3 多个 WiFi 客户端和一台使用 UDP 的服务器

Question

我正在尝试构建具有以下特征的 ns-3 模拟。我想要多个客户端节点通过 WiFi 网络使用 UDP 数据包定期与服务器通信（仅与服务器通信，没有客户端到客户端通信）。服务器将接收数据包并回复。我最终想收集每个客户端-服务器连接的延迟。

我对 ns-3 很陌生，我正在尝试构建一个网络，客户端将数据包发送到服务器，但似乎尽管我所有的客户端都发送数据包，但在不同的时刻，服务器只“监听”一个节点。这是我的代码和输出：

#include "ns3/core-module.h"
#include "ns3/network-module.h"
#include "ns3/wifi-module.h"
#include "ns3/mobility-module.h"
#include "ns3/internet-module.h"
#include "ns3/applications-module.h"
#include "ns3/flow-monitor-module.h"
#include "ns3/packet.h"
#include "ns3/log.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("WirelessNetwork");

void CourseChange(std::string context, Ptr\<const MobilityModel\> model) {
Vector position = model-\>GetPosition();
NS_LOG_UNCOND(context \<\<" x = " \<\< position.x \<\< ", y = " \<\< position.y);
}
// void PacketSentCallback(Ptr\<const Packet\> packet)
// {
//     NS_LOG_UNCOND("Packet sent at " \<\< Simulator::Now().GetSeconds() \<\< " seconds");
// }
// void PacketReceivedCallback(Ptr\<const Packet\> packet)
// {
//     NS_LOG_UNCOND("Packet received at " \<\< Simulator::Now().GetSeconds() \<\< " seconds");
// }

int main (int argc, char \*argv\[\])
{
// Enable logging for this script
LogComponentEnable ("WirelessNetwork", LOG_LEVEL_INFO);

    bool verbose = true;
    uint32_t nWifi=3;
    double simulationTime = 10; // simulation time in seconds
    
    CommandLine cmd;
    
    cmd.AddValue("nWifi", "Number of wifi STA devices", nWifi); 
    cmd.AddValue("verbose", "Tell echo applications to log if true", verbose);
    cmd.Parse(argc,argv);
    if (verbose) {
        LogComponentEnable("PacketSink", LOG_LEVEL_INFO);
        LogComponentEnable("UdpSocketImpl", LOG_LEVEL_INFO);
        LogComponentEnable("UdpClient", LOG_LEVEL_INFO);
        LogComponentEnable("UdpServer", LOG_LEVEL_INFO);
    }
    
    // Create nodes
    NodeContainer wifiStaNode;
    wifiStaNode.Create(1);
    NodeContainer wifiApNode;
    wifiApNode.Create(nWifi);
    
    // Create wireless channel
    YansWifiChannelHelper channel = YansWifiChannelHelper::Default();
    YansWifiPhyHelper phy;
    phy.SetChannel(channel.Create());
    
    // Default IEEE 802.11n (2.4 GHz)
    WifiHelper wifi;
    wifi.SetStandard(WIFI_STANDARD_80211n);
    // wifi.SetRemoteStationManager("ns3::ConstantRateWifiManager",
    //                              "DataMode",
    //                              StringValue("HtMcs7"),
    //                              "ControlMode",
    //                              StringValue("HtMcs0"));
    WifiMacHelper mac;
    
    // Install PHY and MAC
    Ssid ssid = Ssid("ns3-wifi");
    mac.SetType("ns3::StaWifiMac", "Ssid", SsidValue(ssid));
    
    NetDeviceContainer staDevice;
    staDevice = wifi.Install(phy, mac, wifiStaNode);
    
    mac.SetType("ns3::ApWifiMac", "Ssid", SsidValue(ssid));
    
    NetDeviceContainer apDevice;
    apDevice = wifi.Install(phy, mac, wifiApNode);
    
    
    // Mobility
    MobilityHelper mobility;
    Ptr<ListPositionAllocator> positionAlloc = CreateObject<ListPositionAllocator>();
    
    positionAlloc->Add(Vector(0.0, 0.0, 0.0));
    positionAlloc->Add(Vector(1.0, 0.0, 0.0));
    positionAlloc->Add(Vector(2.0, 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
    uint16_t port = 9;
    PacketSinkHelper packetSinkHelper("ns3::UdpSocketFactory", InetSocketAddress(Ipv4Address::GetAny(), port));
    ApplicationContainer serverApp = packetSinkHelper.Install(wifiStaNode.Get(0));
    
    serverApp.Start(Seconds(0.0));
    serverApp.Stop(Seconds(simulationTime + 1));
    
    ApplicationContainer clientApps;
    for (uint32_t i = 0; i < wifiApNode.GetN(); ++i)
    {
        UdpClientHelper client(staNodeInterface.GetAddress(0), port);  // Target the server IP
        client.SetAttribute("MaxPackets", UintegerValue(2));
        client.SetAttribute("PacketSize", UintegerValue(1472));
        ApplicationContainer clientApp = client.Install(wifiApNode.Get(i));
        clientApp.Start(Seconds(1.0+i*2));
        clientApp.Stop(Seconds(10 + 1));
        clientApps.Add(clientApp);
    }
    
    // Populate routing table
    Ipv4GlobalRoutingHelper::PopulateRoutingTables();
    
    // Set simulation time and launch simulation
    Simulator::Stop(Seconds(simulationTime + 1));
    Simulator::Run();
    
    Simulator::Destroy();
    return 0;

}
TraceDelay TX 1472 bytes to 192.168.1.1 Uid: 36 Time: +1sAt time +1.00514s packet sink received 1472 bytes from 192.168.1.2 port 49153 total Rx 1472 bytesTraceDelay TX 1472 bytes to 192.168.1.1 Uid: 71 Time: +2sAt time +2.00024s packet sink received 1472 bytes from 192.168.1.2 port 49153 total Rx 2944 bytesTraceDelay TX 1472 bytes to 192.168.1.1 Uid: 102 Time: +3sTraceDelay TX 1472 bytes to 192.168.1.1 Uid: 133 Time: +4sTraceDelay TX 1472 bytes to 192.168.1.1 Uid: 165 Time: +5sTraceDelay TX 1472 bytes to 192.168.1.1 Uid: 199 Time: +6s

Answer 1

我不知道它是否正确，但它似乎有效，我用 UdpServer 做到了

    NS_LOG_INFO("Create UdpServer application on AP node.");
    uint16_t port = 4000;
    UdpServerHelper server(port);
    ApplicationContainer apps = server.Install(wifiApNode.Get(0));
    apps.Start(Seconds(1.0));
    apps.Stop(Seconds(10.0));


    NS_LOG_INFO("Create UdpClient application on node 0 to send to node 1.");
    uint32_t MaxPacketSize = 1024;
    Time interPacketInterval = Seconds(1);
    uint32_t maxPacketCount = 3;

    ApplicationContainer clientApps;
    UdpClientHelper client(serverAddress, port);
    client.SetAttribute("MaxPackets", UintegerValue(maxPacketCount));
    client.SetAttribute("Interval", TimeValue(interPacketInterval));
    client.SetAttribute("PacketSize", UintegerValue(MaxPacketSize));
    clientApps= client.Install(wifiStaNodes);
    clientApps.Start(Seconds (2.0));
    clientApps.Stop(Seconds (10.0));