declaring Nodes in Ns3 - ns-3

Question

I am completely new to NS3, i am tasked to set two eNBs and one UE between them to demonstrate x2 handover, i have successfully set the eNBs and UE and also set a mobility model for the UE, now i wanted to generate an XML trace file to run on the NetAnim, when i added the following line to my code
AnimationInterface anim ("x2-handover-animation.xml");
anim.SetMobilityPollInterval (Seconds (0.3));
it also two extra nodes, giving me a total of 5 node instead of the three (2 eNBs and 1 UE) i declared.
Your kind assistance is solicited.
Below is the extract of my source code
#include "ns3/core-module.h"
#include "ns3/network-module.h"
#include "ns3/internet-module.h"
#include "ns3/mobility-module.h"
#include "ns3/lte-module.h"
#include "ns3/applications-module.h"
#include "ns3/point-to-point-module.h"
#include "ns3/config-store-module.h"
#include "ns3/csma-module.h"
#include "ns3/wifi-module.h"
#include "ns3/netanim-module.h"
#include "ns3/mobility-helper.h"
#include "ns3/flow-monitor-module.h"
using namespace ns3;
void
NotifyConnectionEstablishedUe (std::string context,
uint64_t imsi,
uint16_t cellid,
uint16_t rnti)
{
std::cout << context
<< " UE IMSI " << imsi
<< ": connected to CellId " << cellid
<< " with RNTI " << rnti
<< std::endl;
}
void
NotifyHandoverStartUe (std::string context,
uint64_t imsi,
uint16_t cellid,
uint16_t rnti,
uint16_t targetCellId)
{
std::cout << context
<< " UE IMSI " << imsi
<< ": previously connected to CellId " << cellid
<< " with RNTI " << rnti
<< ", doing handover to CellId " << targetCellId
<< std::endl;
}
void
NotifyHandoverEndOkUe (std::string context,
uint64_t imsi,
uint16_t cellid,
uint16_t rnti)
{
std::cout << context
<< " UE IMSI " << imsi
<< ": successful handover to CellId " << cellid
<< " with RNTI " << rnti
<< std::endl;
}
void
NotifyConnectionEstablishedEnb (std::string context,
uint64_t imsi,
uint16_t cellid,
uint16_t rnti)
{
std::cout << context
<< " eNB CellId " << cellid
<< ": successful connection of UE with IMSI " << imsi
<< " RNTI " << rnti
<< std::endl;
}
void
NotifyHandoverStartEnb (std::string context,
uint64_t imsi,
uint16_t cellid,
uint16_t rnti,
uint16_t targetCellId)
{
std::cout << context
<< " eNB CellId " << cellid
<< ": start handover of UE with IMSI " << imsi
<< " RNTI " << rnti
<< " to CellId " << targetCellId
<< std::endl;
}
void
NotifyHandoverEndOkEnb (std::string context,
uint64_t imsi,
uint16_t cellid,
uint16_t rnti)
{
std::cout << context
<< " eNB CellId " << cellid
<< ": completed handover of UE with IMSI " << imsi
<< " RNTI " << rnti
<< std::endl;
}
/**
* Sample simulation script for a X2-based handover.
* It instantiates two eNodeB, attaches one UE to the 'source' eNB and
* triggers a handover of the UE towards the 'target' eNB.
*/
NS_LOG_COMPONENT_DEFINE ("EpcX2HandoverExample");
int
main (int argc, char *argv[])
{
uint16_t numberOfUes = 1; // the 1 Ue i declared
uint16_t numberOfEnbs = 2; // the 2 ENBs i declared
uint16_t numBearersPerUe = 0;
double simTime = 10.00;
// change some default attributes so that they are reasonable for
// this scenario, but do this before processing command line
// arguments, so that the user is allowed to override these settings
Config::SetDefault ("ns3::UdpClient::Interval", TimeValue (MilliSeconds(10)));
Config::SetDefault ("ns3::UdpClient::MaxPackets", UintegerValue(1000000));
Config::SetDefault ("ns3::LteHelper::UseIdealRrc", BooleanValue(false));
// Command line arguments
CommandLine cmd;
cmd.AddValue("numberOfUes", "Number of UEs", numberOfUes);
cmd.AddValue("numberOfEnbs", "Number of eNodeBs", numberOfEnbs);
cmd.AddValue("simTime", "Total duration of the simulation (in seconds)",simTime);
cmd.Parse(argc, argv);
Ptr<LteHelper> lteHelper = CreateObject<LteHelper> ();
Ptr<EpcHelper> epcHelper = CreateObject<EpcHelper> ();
lteHelper->SetEpcHelper (epcHelper);
lteHelper->SetSchedulerType("ns3::RrFfMacScheduler");
Ptr<Node> pgw = epcHelper->GetPgwNode ();
// Create a single RemoteHost
NodeContainer remoteHostContainer;
remoteHostContainer.Create (1);
Ptr<Node> remoteHost = remoteHostContainer.Get (0);
InternetStackHelper internet;
internet.Install (remoteHostContainer);
// Create the Internet
PointToPointHelper p2ph;
p2ph.SetDeviceAttribute ("DataRate", DataRateValue (DataRate ("100Gb/s")));
p2ph.SetDeviceAttribute ("Mtu", UintegerValue (1500));
p2ph.SetChannelAttribute ("Delay", TimeValue (Seconds (0.010)));
NetDeviceContainer internetDevices = p2ph.Install (pgw, remoteHost);
Ipv4AddressHelper ipv4h;
ipv4h.SetBase ("1.0.0.0", "255.0.0.0");
Ipv4InterfaceContainer internetIpIfaces = ipv4h.Assign (internetDevices);
Ipv4Address remoteHostAddr = internetIpIfaces.GetAddress (1);
// Routing of the Internet Host (towards the LTE network)
Ipv4StaticRoutingHelper ipv4RoutingHelper;
Ptr<Ipv4StaticRouting> remoteHostStaticRouting =pv4RoutingHelper.GetStaticRouting (remoteHost->GetObject<Ipv4> ());
// interface 0 is localhost, 1 is the p2p device
remoteHostStaticRouting->AddNetworkRouteTo (Ipv4Address ("7.0.0.0"), Ipv4Mask ("255.0.0.0"), 1);
NodeContainer ueNodes;
NodeContainer enbNodes;
enbNodes.Create(numberOfEnbs);
ueNodes.Create(numberOfUes);
AnimationInterface anim ("x2-handover-animation.xml"); //code i added to generate XML file
anim.SetMobilityPollInterval (Seconds (0.3));
MobilityHelper mobility;
mobility.SetMobilityModel ("ns3::RandomDirection2dMobilityModel",
"Bounds", RectangleValue (Rectangle (-50, 50, -50, 50)));
mobility.Install (ueNodes);
mobility.SetMobilityModel ("ns3::ConstantPositionMobilityModel");
mobility.Install (enbNodes);
// Install LTE Devices in eNB and UEs
NetDeviceContainer enbLteDevs = lteHelper->InstallEnbDevice (enbNodes);
NetDeviceContainer ueLteDevs = lteHelper->InstallUeDevice (ueNodes);
// Install the IP stack on the UEs
internet.Install (ueNodes);
Ipv4InterfaceContainer ueIpIfaces;
ueIpIfaces = epcHelper->AssignUeIpv4Address (NetDeviceContainer (ueLteDevs));
// Assign IP address to UEs, and install applications
for (uint32_t u = 0; u < ueNodes.GetN (); ++u)
{
Ptr<Node> ueNode = ueNodes.Get (u);
// Set the default gateway for the UE
Ptr<Ipv4StaticRouting> ueStaticRouting = ipv4RoutingHelper.GetStaticRouting (ueNode->GetObject<Ipv4> ());
ueStaticRouting->SetDefaultRoute (epcHelper->GetUeDefaultGatewayAddress (), 1);
}
// Attach all UEs to the first eNodeB
for (uint16_t i = 0; i < numberOfUes; i++)
{
lteHelper->Attach (ueLteDevs.Get(i), enbLteDevs.Get(0));
}
NS_LOG_LOGIC ("setting up applications");
// Install and start applications on UEs and remote host
uint16_t dlPort = 10000;
uint16_t ulPort = 20000;
// randomize a bit start times to avoid simulation artifacts
// (e.g., buffer overflows due to packet transmissions happening
// exactly at the same time)
Ptr<UniformRandomVariable> startTimeSeconds = CreateObject<UniformRandomVariable> ();
startTimeSeconds->SetAttribute ("Min", DoubleValue (0));
startTimeSeconds->SetAttribute ("Max", DoubleValue (0.010));
for (uint32_t u = 0; u < numberOfUes; ++u)
{
Ptr<Node> ue = ueNodes.Get (u);
// Set the default gateway for the UE
Ptr<Ipv4StaticRouting> ueStaticRouting = ipv4RoutingHelper.GetStaticRouting (ue->GetObject<Ipv4> ());
ueStaticRouting->SetDefaultRoute (epcHelper->GetUeDefaultGatewayAddress (), 1);
for (uint32_t b = 0; b < numBearersPerUe; ++b)
{
++dlPort;
++ulPort;
ApplicationContainer clientApps;
ApplicationContainer serverApps;
NS_LOG_LOGIC ("installing UDP DL app for UE " << u);
UdpClientHelper dlClientHelper (ueIpIfaces.GetAddress (u), dlPort);
clientApps.Add (dlClientHelper.Install (remoteHost));
PacketSinkHelper dlPacketSinkHelper ("ns3::UdpSocketFactory",
InetSocketAddress (Ipv4Address::GetAny (), dlPort));
serverApps.Add (dlPacketSinkHelper.Install (ue));
NS_LOG_LOGIC ("installing UDP UL app for UE " << u);
UdpClientHelper ulClientHelper (remoteHostAddr, ulPort);
clientApps.Add (ulClientHelper.Install (ue));
PacketSinkHelper ulPacketSinkHelper ("ns3::UdpSocketFactory",
InetSocketAddress (Ipv4Address::GetAny (), ulPort));
serverApps.Add (ulPacketSinkHelper.Install (remoteHost));
Ptr<EpcTft> tft = Create<EpcTft> ();
EpcTft::PacketFilter dlpf;
dlpf.localPortStart = dlPort;
dlpf.localPortEnd = dlPort;
tft->Add (dlpf);
EpcTft::PacketFilter ulpf;
ulpf.remotePortStart = ulPort;
ulpf.remotePortEnd = ulPort;
tft->Add (ulpf);
EpsBearer bearer (EpsBearer::NGBR_VIDEO_TCP_DEFAULT);
lteHelper->ActivateDedicatedEpsBearer (ueLteDevs.Get (u), bearer, tft);
Time startTime = Seconds (startTimeSeconds->GetValue ());
serverApps.Start (startTime);
clientApps.Start (startTime);
} // end for b
}
// Add X2 inteface
lteHelper->AddX2Interface (enbNodes);
// X2-based Handover
lteHelper->HandoverRequest (Seconds (0.100), ueLteDevs.Get (0), enbLteDevs.Get (0), enbLteDevs.Get (1));
// Uncomment to enable PCAP tracing
p2ph.EnablePcapAll("lena-x2-handover");
lteHelper->EnableMacTraces ();
lteHelper->EnableRlcTraces ();
lteHelper->EnablePdcpTraces ();
Ptr<RadioBearerStatsCalculator> rlcStats = lteHelper->GetRlcStats ();
rlcStats->SetAttribute ("EpochDuration", TimeValue (Seconds (0.05)));
Ptr<RadioBearerStatsCalculator> pdcpStats = lteHelper->GetPdcpStats ();
pdcpStats->SetAttribute ("EpochDuration", TimeValue (Seconds (0.05)));
// connect custom trace sinks for RRC connection establishment and handover notification
Config::Connect ("/NodeList/*/DeviceList/*/LteEnbRrc/ConnectionEstablished",
MakeCallback (&NotifyConnectionEstablishedEnb));
Config::Connect ("/NodeList/*/DeviceList/*/LteUeRrc/ConnectionEstablished",
MakeCallback (&NotifyConnectionEstablishedUe));
Config::Connect ("/NodeList/*/DeviceList/*/LteEnbRrc/HandoverStart",
MakeCallback (&NotifyHandoverStartEnb));
Config::Connect ("/NodeList/*/DeviceList/*/LteUeRrc/HandoverStart",
MakeCallback (&NotifyHandoverStartUe));
Config::Connect ("/NodeList/*/DeviceList/*/LteEnbRrc/HandoverEndOk",
MakeCallback (&NotifyHandoverEndOkEnb));
Config::Connect ("/NodeList/*/DeviceList/*/LteUeRrc/HandoverEndOk",
MakeCallback (&NotifyHandoverEndOkUe));
Simulator::Stop(Seconds(simTime));
Simulator::Run();
// GtkConfigStore config;
// config.ConfigureAttributes();
Simulator::Destroy();
return 0;
}

Answer 1

As I see in this code you have created 5 Nodes not 3.
The First one is pgw node which is and EPC entity
Ptr<Node> pgw = epcHelper->GetPgwNode ();
The Second one is a remote host
remoteHostContainer.Create (1);
These two nodes are connected point to point using the following code
NetDeviceContainer internetDevices = p2ph.Install (pgw, remoteHost);
The third and fourth nodes are the ENB Nodes "numberOfEnbs = 2;"
enbNodes.Create(numberOfEnbs);
The fifth is the Ue node "numberOfUes = 1;"
ueNodes.Create(numberOfUes);
Thus you should have 5 nodes not three :)
The first two nodes represents the Internet connection that is connected to the LTE network that you created. While the last 3 nodes represents your LTE Network.