lte: Random variable stream assignments on EPC nodes

src/lte/helper/epc-helper.h

@@ -169,6 +169,13 @@ public:
    */
   virtual Ipv6Address GetUeDefaultGatewayAddress6 () = 0;
 
+  /**
+   * Assign a fixed random variable stream number to the random variables used.
+   *
+   * \param stream first stream index to use
+   * \return the number of stream indices (possibly zero) that have been assigned
+  */
+  virtual int64_t AssignStreams (int64_t stream) = 0;
 
 };
 

src/lte/helper/lte-helper.cc

@@ -1481,6 +1481,10 @@ LteHelper::AssignStreams (NetDeviceContainer c, int64_t stream)
           currentStream += ueMac->AssignStreams (currentStream);
         }
     }
+  if (m_epcHelper)
+    {
+      currentStream += m_epcHelper->AssignStreams (currentStream);
+    }
   return (currentStream - stream);
 }
 

src/lte/helper/lte-helper.h

@@ -652,6 +652,9 @@ public:
    * If TraceFadingLossModel has been set as the fading model type, this method
    * will also assign a stream number to it, if none has been assigned before.
    *
+   * If an EPC has been configured, streams will be assigned on the EPC
+   * nodes as well via EpcHelper::AssignStreams ().
+   *
    * \param c NetDeviceContainer of the set of net devices for which the
    *          LteNetDevice should be modified to use a fixed stream
    * \param stream first stream index to use

src/lte/helper/no-backhaul-epc-helper.cc

@@ -568,4 +568,18 @@ NoBackhaulEpcHelper::AddS1Interface (Ptr<Node> enb, Ipv4Address enbAddress, Ipv4
   enbApp->SetS1apSapMme (m_mmeApp->GetS1apSapMme ());
 }
 
+int64_t
+NoBackhaulEpcHelper::AssignStreams (int64_t stream)
+{
+  int64_t currentStream = stream;
+  NS_ABORT_MSG_UNLESS (m_pgw && m_sgw && m_mme, "Running AssignStreams on empty node pointers");
+  InternetStackHelper internet;
+  NodeContainer nc;
+  nc.Add (m_pgw);
+  nc.Add (m_sgw);
+  nc.Add (m_mme);
+  currentStream += internet.AssignStreams (nc, currentStream);
+  return (currentStream - stream);
+}
+
 } // namespace ns3

src/lte/helper/no-backhaul-epc-helper.h

@@ -77,6 +77,7 @@ public:
   virtual Ipv6InterfaceContainer AssignUeIpv6Address (NetDeviceContainer ueDevices);
   virtual Ipv4Address GetUeDefaultGatewayAddress ();
   virtual Ipv6Address GetUeDefaultGatewayAddress6 ();
+  virtual int64_t AssignStreams (int64_t stream) override;
 
 protected:
   /**