Query on lena_simple_epc.cc

[Ramakrishnan S]

Hi, 

Just had a query on LTE example code "lena_simple_epc.cc"

This example code has the following lines for installing the UDP client server on each eNB and Client. 

Though I understand the code construct - I am unclear on the what is the significance of the the highlighted Client-Server code associated with "otherPort". 

Is it related to UE-UE Communication through BTS? 

I presume we could remove it if only RemoteHost-UE (Downlink) and UE-RemoteHost (Uplink) is needed? 

Can anyone clarify?

regards

Ramakrishnan

************************ Code Snippet **********************

// Install and start applications on UEs and remote host

  uint16_t dlPort = 1234;

  uint16_t ulPort = 2000;

  uint16_t otherPort = 3000;

  ApplicationContainer clientApps;

  ApplicationContainer serverApps;

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

    {

      ++ulPort;

      ++otherPort;

      PacketSinkHelper dlPacketSinkHelper ("ns3::UdpSocketFactory", InetSocketAddress (Ipv4Address::GetAny (), dlPort));

      PacketSinkHelper ulPacketSinkHelper ("ns3::UdpSocketFactory", InetSocketAddress (Ipv4Address::GetAny (), ulPort));

      PacketSinkHelper packetSinkHelper ("ns3::UdpSocketFactory", InetSocketAddress (Ipv4Address::GetAny (), otherPort));

      serverApps.Add (dlPacketSinkHelper.Install (ueNodes.Get(u)));

      serverApps.Add (ulPacketSinkHelper.Install (remoteHost));

      serverApps.Add (packetSinkHelper.Install (ueNodes.Get(u)));

      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)));

        }

    }

  serverApps.Start (Seconds (0.01));

  clientApps.Start (Seconds (0.01));

  lteHelper->EnableTraces ();