Detach from one Enb and Attach to another

[Marios Me]

Hi guys I have the following scenario in which I detach the Ue from the first eNB and trying to attach it to the second one . The fact is that the UE should be in camped mode before the second attachment. After the release I try to attach it in the second eNB but it doesn't happen anything ! It stays attached to the first one !! HAve you got any idea about it ?? It's extremely emergency !!!

The scenario :

#include <iostream>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include "ns3/lte-helper.h"
#include "ns3/epc-helper.h"
#include "ns3/core-module.h"
#include "ns3/network-module.h"
#include "ns3/ipv4-global-routing-helper.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-helper.h"
#include <ns3/config-store-module.h>
#include "ns3/epc-ue-nas.h"


using namespace ns3;

Ptr <LteHelper> ltehelper = CreateObject<LteHelper>();
Ptr<LteUeRrc> lteuerrc = CreateObject<LteUeRrc>();
NodeContainer enbNodes;
NetDeviceContainer ueDevs,enbDevs;
uint8_t bearerIdForDetach;
enum EpsBearer::Qci q = EpsBearer::GBR_CONV_VOICE;
EpsBearer bearer (q);


static const std::string g_ueRrcStateName[LteUeRrc::NUM_STATES] =
{
  "IDLE_START",
  "IDLE_CELL_SEARCH",
  "IDLE_WAIT_MIB_SIB1",
  "IDLE_WAIT_MIB",
  "IDLE_WAIT_SIB1",
  "IDLE_CAMPED_NORMALLY",
  "IDLE_WAIT_SIB2",
  "IDLE_RANDOM_ACCESS",
  "IDLE_CONNECTING",
  "CONNECTED_NORMALLY",
  "CONNECTED_HANDOVER",
  "CONNECTED_PHY_PROBLEM",
  "CONNECTED_REESTABLISHING"
};

static const std::string & ToString (LteUeRrc::State s)
{
  return g_ueRrcStateName[s];
}


static void StateTransitionCallback ( std::string context, uint64_t imsi, uint16_t cellId, uint16_t rnti, LteUeRrc::State oldState, LteUeRrc::State newState)
{
  std::cout << " UE IMSI " << imsi
            << " CellId " << cellId
            << " RNTI " << rnti
            << " State changed from: " << ToString(oldState)
            << " to: " << ToString(newState)
            << std::endl;
}


void handler (){

  lteuerrc->ReleaseRrcResource ();
  ltehelper->Attach (ueDevs.Get (0),enbDevs.Get (0));
}


int main (int argc , char * argv[]){

  CommandLine cmd;
  cmd.Parse (argc, argv);

  double interPacketInterval = 100;

  GlobalValue::Bind ("ChecksumEnabled", BooleanValue (true));

  Ptr<PointToPointEpcHelper> epcHelper = CreateObject<PointToPointEpcHelper> ();
  ltehelper->SetEpcHelper (epcHelper);


  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);
  // interface 0 is localhost, 1 is the p2p device
  Ipv4Address remoteHostAddr = internetIpIfaces.GetAddress (1);

  Ipv4StaticRoutingHelper ipv4RoutingHelper;
  Ptr<Ipv4StaticRouting> remoteHostStaticRouting = ipv4RoutingHelper.GetStaticRouting (remoteHost->GetObject<Ipv4> ());
  remoteHostStaticRouting->AddNetworkRouteTo (Ipv4Address ("7.0.0.0"), Ipv4Mask ("255.0.0.0"), 1);




  NodeContainer ueNodes;

  ueNodes.Create (1);
  enbNodes.Create (2);



  MobilityHelper mobility;
  mobility.SetMobilityModel ("ns3::ConstantPositionMobilityModel");
  Ptr<ListPositionAllocator> positionAlloc = CreateObject<ListPositionAllocator> ();
  for (uint16_t i = 1; i <=2; i++)
    {
      if (i==2){
          positionAlloc->Add (Vector(10, 0, 0));
        }
      else{
          positionAlloc->Add (Vector(1000,0,0));
        }
      mobility.SetPositionAllocator(positionAlloc);
      mobility.Install (enbNodes);
    }

//  positionAlloc->Add (Vector(10, 0, 0));
//  mobility.SetPositionAllocator(positionAlloc);
//  mobility.Install (enbNodes);
  Ptr<ListPositionAllocator> positionAlloc2 = CreateObject<ListPositionAllocator> ();
  mobility.SetMobilityModel ("ns3::ConstantPositionMobilityModel");
  positionAlloc2->Add (Vector(50,0,0));
  mobility.SetPositionAllocator (positionAlloc2);
  mobility.Install (ueNodes);



  //  NetDeviceContainer ueDevs,enbDevs;
  enbDevs = ltehelper->InstallEnbDevice (enbNodes);
  ueDevs = ltehelper->InstallUeDevice (ueNodes);


  // Install the IP stack on the UEs
  internet.Install (ueNodes);
  Ipv4InterfaceContainer ueIpIface;
  ueIpIface = epcHelper->AssignUeIpv4Address (NetDeviceContainer (ueDevs));
  // 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);
    }

  ltehelper->Attach (ueDevs.Get (0),enbDevs.Get (0));


  bearerIdForDetach = ltehelper->ActivateDedicatedEpsBearer(ueDevs, bearer,EpcTft::Default ());

  Ptr <NetDevice> ueDevice = ueDevs.Get(0);
  Ptr <LteUeNetDevice> ueLteDevice = ueDevice->GetObject<LteUeNetDevice>();
  lteuerrc = ueLteDevice->GetRrc();


  uint16_t dlPort = 1234;
  uint16_t ulPort = 2000;
  uint16_t otherPort = 3000;

  ApplicationContainer clientApps;

  for (uint32_t u = 0; u < ueNodes.GetN (); ++u)
    {
      ++ulPort;
      ++otherPort;

      UdpClientHelper dlClient (ueIpIface.GetAddress (u), dlPort);
      dlClient.SetAttribute ("Interval", TimeValue (MilliSeconds(interPacketInterval)));
      dlClient.SetAttribute ("MaxPackets", UintegerValue(1000000));

      UdpClientHelper ulClient (remoteHostAddr, ulPort);
      ulClient.SetAttribute ("Interval", TimeValue (MilliSeconds(interPacketInterval)));
      ulClient.SetAttribute ("MaxPackets", UintegerValue(1000000));

      UdpClientHelper client (ueIpIface.GetAddress (u), otherPort);
      client.SetAttribute ("Interval", TimeValue (MilliSeconds(interPacketInterval)));
      client.SetAttribute ("MaxPackets", UintegerValue(1000000));

      clientApps.Add (dlClient.Install (remoteHost));
      clientApps.Add (ulClient.Install (ueNodes.Get(u)));
      if (u+1 < ueNodes.GetN ())
        {
          clientApps.Add (client.Install (ueNodes.Get(u+1)));
        }
      else
        {
          clientApps.Add (client.Install (ueNodes.Get(0)));
        }
    }

  clientApps.Start (Seconds(0.01));
  clientApps.Stop (Seconds(3));



  ltehelper->EnablePhyTraces ();
  ltehelper->EnableMacTraces ();
  ltehelper->EnableRlcTraces ();
  ltehelper->EnablePdcpTraces ();



  Config::Connect("/NodeList/*/DeviceList/*/LteUeRrc/StateTransition",
                  MakeCallback(&StateTransitionCallback));

  Simulator::Stop (Seconds(20));
  Simulator::Schedule(Seconds(5),&handler);
  Simulator::Run ();
  Simulator::Destroy ();

  return 0;

}

The ReleaseRrcResource function :

void LteUeRrc::ReleaseRrcResource()
{
    std::map<uint8_t, Ptr<LteDataRadioBearerInfo> >::iterator it;

    switch (m_state)
    {
        case IDLE_START:
        case IDLE_CELL_SEARCH:
        case IDLE_WAIT_MIB_SIB1:
        case IDLE_WAIT_MIB:
        case IDLE_WAIT_SIB1:
        case IDLE_CAMPED_NORMALLY:
            NS_LOG_INFO ("already rrc released");
        break;

        case IDLE_WAIT_SIB2:
        case IDLE_CONNECTING:
        break;
        case CONNECTED_NORMALLY:
        case CONNECTED_HANDOVER:
        case CONNECTED_PHY_PROBLEM:
        case CONNECTED_REESTABLISHING:
            m_asSapUser->NotifyConnectionReleased ();
            m_cmacSapProvider->RemoveLc (1);
            for (it = m_drbMap.begin (); it != m_drbMap.end (); ++it)
            {
                m_cmacSapProvider->RemoveLc (it->second->m_logicalChannelIdentity);
            }
            m_drbMap.clear ();
            m_bid2DrbidMap.clear ();
            m_srb1 = 0;
            SwitchToState (IDLE_CAMPED_NORMALLY);
        break;
        default:
        break;
    }
}

[Konstantinos]

Dear Marios,

Please do not post the entire code inside the message, use Attachments in the future.

Have you looked at the example src/lte/examples/lena-x2-handover.cc ? 

Also you ask "After the release I try to attach it in the second eNB but it doesn't happen anything ! It stays attached to the first one !! HAve you got any idea about it ?? "
Have a look at your code

void handler (){

  lteuerrc->ReleaseRrcResource ();
  ltehelper->Attach (ueDevs.Get (0),enbDevs.Get (0));
}

Your handler attaches the UE to the first eNB!

Regards,

K.