diff --git a/CHANGES.html b/CHANGES.html
index d21e57c5c..5ed2eec3f 100644
--- a/CHANGES.html
+++ b/CHANGES.html
@@ -54,6 +54,7 @@ us a note on ns-developers mailing list.</p>
 <h1>Changes from ns-3.29 to ns-3.30</h1>
 <h2>New API:</h2>
 <ul>
+<li>Added the attribute <b>Release</b> to the class <b>EpsBearer</b>, to select the release (e.g., release 15)</li>
 <li>The attributes <b>RegularWifiMac::HtSupported</b>, <b>RegularWifiMac::VhtSupported</b>, <b>RegularWifiMac::HeSupported</b>, <b>RegularWifiMac::RifsSupported</b>, <b>WifiPhy::ShortGuardEnabled</b>, <b>WifiPhy::GuardInterval</b> and <b>WifiPhy::GreenfieldEnabled</b> have been deprecated. Intead, it is advised to use <b>WifiNetDevice::HtConfiguration</b>, <b>WifiNetDevice::VhtConfiguration</b> and <b>WifiNetDevice::HeConfiguration</b>.</li>
 <li>A new attribute <b>WifiPhy::PostReceptionErrorModel</b> has been added to force specific packet drops.</li>
 <li>A new attribute <b>WifiPhy::PreambleDetectionModel</b> has been added to decide whether PHY preambles are successfully detected.</li>
@@ -75,6 +76,10 @@ us a note on ns-developers mailing list.</p>
     The WifiPhy attribute "CcaMode1Threshold" has been renamed to "CcaEdThreshold", 
     and the WifiPhy attribute "EnergyDetectionThreshold" has been replaced by a new attribute called "RxSensitivity"
   </li>
+  <li>
+    It is now possible to know the size of the SpectrumValue underlying std::vector, as well as
+    accessing read-only every element of it.
+  </li>
 </ul>
 <h2>Changes to build system:</h2>
 <ul>
diff --git a/RELEASE_NOTES b/RELEASE_NOTES
index 8dd8915bd..f74cb57ae 100644
--- a/RELEASE_NOTES
+++ b/RELEASE_NOTES
@@ -32,6 +32,7 @@ Bugs fixed
 - Bug 2992 - lte: Send method of the LteUeNetDevice doesn't use protocolNumber parameter
 - Bug 2997 - lte: EpcTft::PacketFilter::Matches does not use ipv6 address to match an IP packet
 - Bug 2860 - mobility: Set Z coordinate for position-allocation classes
+- Bug 2893 - lte: GetPgw in helper should be const
 - Bug 3027 - lte: S1 signalling is done before RRC connection establishment is finished
 
 Known issues
diff --git a/src/lte/helper/emu-epc-helper.cc b/src/lte/helper/emu-epc-helper.cc
index 6e5fded64..5c113acf2 100644
--- a/src/lte/helper/emu-epc-helper.cc
+++ b/src/lte/helper/emu-epc-helper.cc
@@ -402,7 +402,7 @@ EmuEpcHelper::ActivateEpsBearer (Ptr<NetDevice> ueDevice, uint64_t imsi, Ptr<Epc
 
 
 Ptr<Node>
-EmuEpcHelper::GetPgwNode ()
+EmuEpcHelper::GetPgwNode () const
 {
   return m_sgwPgw;
 }
diff --git a/src/lte/helper/emu-epc-helper.h b/src/lte/helper/emu-epc-helper.h
index 9f3126978..267dd737a 100644
--- a/src/lte/helper/emu-epc-helper.h
+++ b/src/lte/helper/emu-epc-helper.h
@@ -80,7 +80,7 @@ public:
   virtual void AddUe (Ptr<NetDevice> ueLteDevice, uint64_t imsi);
   virtual void AddX2Interface (Ptr<Node> enbNode1, Ptr<Node> enbNode2);
   virtual uint8_t ActivateEpsBearer (Ptr<NetDevice> ueLteDevice, uint64_t imsi, Ptr<EpcTft> tft, EpsBearer bearer);
-  virtual Ptr<Node> GetPgwNode ();
+  virtual Ptr<Node> GetPgwNode () const;
   virtual Ipv4InterfaceContainer AssignUeIpv4Address (NetDeviceContainer ueDevices);
   virtual Ipv6InterfaceContainer AssignUeIpv6Address (NetDeviceContainer ueDevices);
   virtual Ipv4Address GetUeDefaultGatewayAddress ();
diff --git a/src/lte/helper/epc-helper.h b/src/lte/helper/epc-helper.h
index 38b36d7c4..a75b626a1 100644
--- a/src/lte/helper/epc-helper.h
+++ b/src/lte/helper/epc-helper.h
@@ -120,7 +120,7 @@ public:
    * intended for this method is to allow the user to configure the Gi
    * interface of the PGW, i.e., to connect the PGW to the internet.
    */
-  virtual Ptr<Node> GetPgwNode () = 0;
+  virtual Ptr<Node> GetPgwNode () const = 0;
 
   /** 
    * Assign IPv4 addresses to UE devices
diff --git a/src/lte/helper/lte-helper.cc b/src/lte/helper/lte-helper.cc
index dde823e4b..b68730cf8 100644
--- a/src/lte/helper/lte-helper.cc
+++ b/src/lte/helper/lte-helper.cc
@@ -518,7 +518,7 @@ LteHelper::InstallSingleEnbDevice (Ptr<Node> n)
                    m_noOfCcs << ")");
 
   // create component carrier map for this eNb device
-  std::map<uint8_t,Ptr<ComponentCarrierEnb> > ccMap;
+  std::map<uint8_t,Ptr<ComponentCarrierBaseStation> > ccMap;
   for (std::map<uint8_t, ComponentCarrier >::iterator it = m_componentCarrierPhyParams.begin ();
        it != m_componentCarrierPhyParams.end ();
        ++it)
@@ -539,7 +539,7 @@ LteHelper::InstallSingleEnbDevice (Ptr<Node> n)
   NS_ABORT_MSG_IF (m_useCa && ccMap.size()<2, "You have to either specify carriers or disable carrier aggregation");
   NS_ASSERT (ccMap.size () == m_noOfCcs);
 
-  for (std::map<uint8_t,Ptr<ComponentCarrierEnb> >::iterator it = ccMap.begin (); it != ccMap.end (); ++it)
+  for (auto it = ccMap.begin (); it != ccMap.end (); ++it)
     {
       NS_LOG_DEBUG (this << "component carrier map size " << (uint16_t) ccMap.size ());
       Ptr<LteSpectrumPhy> dlPhy = CreateObject<LteSpectrumPhy> ();
@@ -580,12 +580,10 @@ LteHelper::InstallSingleEnbDevice (Ptr<Node> n)
       Ptr<LteEnbMac> mac = CreateObject<LteEnbMac> ();
       Ptr<FfMacScheduler> sched = m_schedulerFactory.Create<FfMacScheduler> ();
       Ptr<LteFfrAlgorithm> ffrAlgorithm = m_ffrAlgorithmFactory.Create<LteFfrAlgorithm> ();
-      it->second->SetMac (mac);
-      it->second->SetFfMacScheduler (sched);
-      it->second->SetFfrAlgorithm (ffrAlgorithm);
-  
-      it->second->SetPhy (phy);
-
+      DynamicCast<ComponentCarrierEnb> (it->second)->SetMac (mac);
+      DynamicCast<ComponentCarrierEnb> (it->second)->SetFfMacScheduler (sched);
+      DynamicCast<ComponentCarrierEnb> (it->second)->SetFfrAlgorithm (ffrAlgorithm);
+      DynamicCast<ComponentCarrierEnb> (it->second)->SetPhy (phy);
     }
 
   Ptr<LteEnbRrc> rrc = CreateObject<LteEnbRrc> ();
@@ -642,41 +640,41 @@ LteHelper::InstallSingleEnbDevice (Ptr<Node> n)
   rrc->SetLteMacSapProvider (ccmEnbManager->GetLteMacSapProvider ());
 
   bool ccmTest;
-  for (std::map<uint8_t,Ptr<ComponentCarrierEnb> >::iterator it = ccMap.begin (); it != ccMap.end (); ++it)
+  for (auto it = ccMap.begin (); it != ccMap.end (); ++it)
     {
-      it->second->GetPhy ()->SetLteEnbCphySapUser (rrc->GetLteEnbCphySapUser (it->first));
-      rrc->SetLteEnbCphySapProvider (it->second->GetPhy ()->GetLteEnbCphySapProvider (), it->first);
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetPhy ()->SetLteEnbCphySapUser (rrc->GetLteEnbCphySapUser (it->first));
+      rrc->SetLteEnbCphySapProvider (DynamicCast<ComponentCarrierEnb> (it->second)->GetPhy ()->GetLteEnbCphySapProvider (), it->first);
 
-      rrc->SetLteEnbCmacSapProvider (it->second->GetMac ()->GetLteEnbCmacSapProvider (),it->first );
-      it->second->GetMac ()->SetLteEnbCmacSapUser (rrc->GetLteEnbCmacSapUser (it->first));
+      rrc->SetLteEnbCmacSapProvider (DynamicCast<ComponentCarrierEnb> (it->second)->GetMac ()->GetLteEnbCmacSapProvider (),it->first );
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetMac ()->SetLteEnbCmacSapUser (rrc->GetLteEnbCmacSapUser (it->first));
 
-      it->second->GetPhy ()->SetComponentCarrierId (it->first);
-      it->second->GetMac ()->SetComponentCarrierId (it->first);
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetPhy ()->SetComponentCarrierId (it->first);
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetMac ()->SetComponentCarrierId (it->first);
       //FFR SAP
-      it->second->GetFfMacScheduler ()->SetLteFfrSapProvider (it->second->GetFfrAlgorithm ()->GetLteFfrSapProvider ());
-      it->second->GetFfrAlgorithm ()->SetLteFfrSapUser (it->second->GetFfMacScheduler ()->GetLteFfrSapUser ());
-      rrc->SetLteFfrRrcSapProvider (it->second->GetFfrAlgorithm ()->GetLteFfrRrcSapProvider (), it->first);
-      it->second->GetFfrAlgorithm ()->SetLteFfrRrcSapUser (rrc->GetLteFfrRrcSapUser (it->first));
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetFfMacScheduler ()->SetLteFfrSapProvider (DynamicCast<ComponentCarrierEnb> (it->second)->GetFfrAlgorithm ()->GetLteFfrSapProvider ());
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetFfrAlgorithm ()->SetLteFfrSapUser (DynamicCast<ComponentCarrierEnb> (it->second)->GetFfMacScheduler ()->GetLteFfrSapUser ());
+      rrc->SetLteFfrRrcSapProvider (DynamicCast<ComponentCarrierEnb> (it->second)->GetFfrAlgorithm ()->GetLteFfrRrcSapProvider (), it->first);
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetFfrAlgorithm ()->SetLteFfrRrcSapUser (rrc->GetLteFfrRrcSapUser (it->first));
       //FFR SAP END
 
       // PHY <--> MAC SAP
-      it->second->GetPhy ()->SetLteEnbPhySapUser (it->second->GetMac ()->GetLteEnbPhySapUser ());
-      it->second->GetMac ()->SetLteEnbPhySapProvider (it->second->GetPhy ()->GetLteEnbPhySapProvider ());
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetPhy ()->SetLteEnbPhySapUser (DynamicCast<ComponentCarrierEnb> (it->second)->GetMac ()->GetLteEnbPhySapUser ());
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetMac ()->SetLteEnbPhySapProvider (DynamicCast<ComponentCarrierEnb> (it->second)->GetPhy ()->GetLteEnbPhySapProvider ());
       // PHY <--> MAC SAP END
 
       //Scheduler SAP
-      it->second->GetMac ()->SetFfMacSchedSapProvider (it->second->GetFfMacScheduler ()->GetFfMacSchedSapProvider ());
-      it->second->GetMac ()->SetFfMacCschedSapProvider (it->second->GetFfMacScheduler ()->GetFfMacCschedSapProvider ());
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetMac ()->SetFfMacSchedSapProvider (DynamicCast<ComponentCarrierEnb> (it->second)->GetFfMacScheduler ()->GetFfMacSchedSapProvider ());
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetMac ()->SetFfMacCschedSapProvider (DynamicCast<ComponentCarrierEnb> (it->second)->GetFfMacScheduler ()->GetFfMacCschedSapProvider ());
 
-      it->second->GetFfMacScheduler ()->SetFfMacSchedSapUser (it->second->GetMac ()->GetFfMacSchedSapUser ());
-      it->second->GetFfMacScheduler ()->SetFfMacCschedSapUser (it->second->GetMac ()->GetFfMacCschedSapUser ());
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetFfMacScheduler ()->SetFfMacSchedSapUser (DynamicCast<ComponentCarrierEnb> (it->second)->GetMac ()->GetFfMacSchedSapUser ());
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetFfMacScheduler ()->SetFfMacCschedSapUser (DynamicCast<ComponentCarrierEnb> (it->second)->GetMac ()->GetFfMacCschedSapUser ());
       // Scheduler SAP END
 
-      it->second->GetMac ()->SetLteCcmMacSapUser (ccmEnbManager->GetLteCcmMacSapUser ());
-      ccmEnbManager->SetCcmMacSapProviders (it->first, it->second->GetMac ()->GetLteCcmMacSapProvider ());
+      DynamicCast<ComponentCarrierEnb> (it->second)->GetMac ()->SetLteCcmMacSapUser (ccmEnbManager->GetLteCcmMacSapUser ());
+      ccmEnbManager->SetCcmMacSapProviders (it->first, DynamicCast<ComponentCarrierEnb> (it->second)->GetMac ()->GetLteCcmMacSapProvider ());
 
       // insert the pointer to the LteMacSapProvider interface of the MAC layer of the specific component carrier
-      ccmTest = ccmEnbManager->SetMacSapProvider (it->first, it->second->GetMac ()->GetLteMacSapProvider());
+      ccmTest = ccmEnbManager->SetMacSapProvider (it->first, DynamicCast<ComponentCarrierEnb> (it->second)->GetMac ()->GetLteMacSapProvider());
 
       if (ccmTest == false)
         {
@@ -690,10 +688,10 @@ LteHelper::InstallSingleEnbDevice (Ptr<Node> n)
   dev->SetAttribute ("CellId", UintegerValue (cellId));
   dev->SetAttribute ("LteEnbComponentCarrierManager", PointerValue (ccmEnbManager));
   dev->SetCcMap (ccMap);
-  std::map<uint8_t,Ptr<ComponentCarrierEnb> >::iterator it = ccMap.begin ();
+  std::map<uint8_t,Ptr<ComponentCarrierBaseStation> >::iterator it = ccMap.begin ();
   dev->SetAttribute ("LteEnbRrc", PointerValue (rrc)); 
   dev->SetAttribute ("LteHandoverAlgorithm", PointerValue (handoverAlgorithm));
-  dev->SetAttribute ("LteFfrAlgorithm", PointerValue (it->second->GetFfrAlgorithm ()));
+  dev->SetAttribute ("LteFfrAlgorithm", PointerValue (DynamicCast<ComponentCarrierEnb> (it->second)->GetFfrAlgorithm ()));
 
   if (m_isAnrEnabled)
     {
@@ -705,7 +703,7 @@ LteHelper::InstallSingleEnbDevice (Ptr<Node> n)
 
   for (it = ccMap.begin (); it != ccMap.end (); ++it)
     {
-      Ptr<LteEnbPhy> ccPhy = it->second->GetPhy ();
+      Ptr<LteEnbPhy> ccPhy = DynamicCast<ComponentCarrierEnb> (it->second)->GetPhy ();
       ccPhy->SetDevice (dev);
       ccPhy->GetUlSpectrumPhy ()->SetDevice (dev);
       ccPhy->GetDlSpectrumPhy ()->SetDevice (dev);
@@ -736,7 +734,7 @@ LteHelper::InstallSingleEnbDevice (Ptr<Node> n)
 
   for (it = ccMap.begin (); it != ccMap.end (); ++it)
     {
-      m_uplinkChannel->AddRx (it->second->GetPhy ()->GetUlSpectrumPhy ());
+      m_uplinkChannel->AddRx (DynamicCast<ComponentCarrierEnb>(it->second)->GetPhy ()->GetUlSpectrumPhy ());
     }
 
   if (m_epcHelper != 0)
@@ -1459,11 +1457,11 @@ LteHelper::AssignStreams (NetDeviceContainer c, int64_t stream)
       Ptr<LteEnbNetDevice> lteEnb = DynamicCast<LteEnbNetDevice> (netDevice);
       if (lteEnb)
         {
-          std::map< uint8_t, Ptr <ComponentCarrierEnb> > tmpMap = lteEnb->GetCcMap ();
-          std::map< uint8_t, Ptr <ComponentCarrierEnb> >::iterator it;
+          std::map< uint8_t, Ptr <ComponentCarrierBaseStation> > tmpMap = lteEnb->GetCcMap ();
+          std::map< uint8_t, Ptr <ComponentCarrierBaseStation> >::iterator it;
           it = tmpMap.begin ();
-          Ptr<LteSpectrumPhy> dlPhy = it->second->GetPhy ()->GetDownlinkSpectrumPhy ();
-          Ptr<LteSpectrumPhy> ulPhy = it->second->GetPhy ()->GetUplinkSpectrumPhy ();
+          Ptr<LteSpectrumPhy> dlPhy = DynamicCast<ComponentCarrierEnb> (it->second)->GetPhy ()->GetDownlinkSpectrumPhy ();
+          Ptr<LteSpectrumPhy> ulPhy = DynamicCast<ComponentCarrierEnb> (it->second)->GetPhy ()->GetUplinkSpectrumPhy ();
           currentStream += dlPhy->AssignStreams (currentStream);
           currentStream += ulPhy->AssignStreams (currentStream);
         }
diff --git a/src/lte/helper/point-to-point-epc-helper.cc b/src/lte/helper/point-to-point-epc-helper.cc
index 380e7036b..fe6304e65 100644
--- a/src/lte/helper/point-to-point-epc-helper.cc
+++ b/src/lte/helper/point-to-point-epc-helper.cc
@@ -546,7 +546,7 @@ PointToPointEpcHelper::ActivateEpsBearer (Ptr<NetDevice> ueDevice, uint64_t imsi
 }
 
 Ptr<Node>
-PointToPointEpcHelper::GetPgwNode ()
+PointToPointEpcHelper::GetPgwNode () const
 {
   return m_pgw;
 }
diff --git a/src/lte/helper/point-to-point-epc-helper.h b/src/lte/helper/point-to-point-epc-helper.h
index 980d8bc78..b2e252aa5 100644
--- a/src/lte/helper/point-to-point-epc-helper.h
+++ b/src/lte/helper/point-to-point-epc-helper.h
@@ -77,7 +77,7 @@ public:
   virtual void AddUe (Ptr<NetDevice> ueLteDevice, uint64_t imsi);
   virtual void AddX2Interface (Ptr<Node> enbNode1, Ptr<Node> enbNode2);
   virtual uint8_t ActivateEpsBearer (Ptr<NetDevice> ueLteDevice, uint64_t imsi, Ptr<EpcTft> tft, EpsBearer bearer);
-  virtual Ptr<Node> GetPgwNode ();
+  virtual Ptr<Node> GetPgwNode () const;
   virtual Ipv4InterfaceContainer AssignUeIpv4Address (NetDeviceContainer ueDevices);
   virtual Ipv6InterfaceContainer AssignUeIpv6Address (NetDeviceContainer ueDevices);
   virtual Ipv4Address GetUeDefaultGatewayAddress ();
diff --git a/src/lte/model/component-carrier-enb.cc b/src/lte/model/component-carrier-enb.cc
index 98c1f2dee..fb77e2c37 100644
--- a/src/lte/model/component-carrier-enb.cc
+++ b/src/lte/model/component-carrier-enb.cc
@@ -116,12 +116,6 @@ ComponentCarrierEnb::DoInitialize (void)
 
 }
 
-uint16_t
-ComponentCarrierEnb::GetCellId ()
-{
-  return m_cellId;
-}
-
 Ptr<LteEnbPhy>
 ComponentCarrierEnb::GetPhy ()
 {
@@ -129,12 +123,6 @@ ComponentCarrierEnb::GetPhy ()
   return m_phy;
 }
 
-void
-ComponentCarrierEnb::SetCellId (uint16_t cellId)
-{
-  NS_LOG_FUNCTION (this << cellId);
-  m_cellId = cellId;
-}
 
 void 
 ComponentCarrierEnb::SetPhy (Ptr<LteEnbPhy> s)
@@ -184,6 +172,40 @@ ComponentCarrierEnb::SetFfMacScheduler (Ptr<FfMacScheduler> s)
   m_scheduler = s;
 } 
 
+TypeId ComponentCarrierBaseStation::GetTypeId (void)
+{
+  static TypeId
+    tid =
+    TypeId ("ns3::ComponentCarrierBaseStation")
+    .SetParent<ComponentCarrier> ()
+    .AddConstructor<ComponentCarrierBaseStation> ()
+  ;
+  return tid;
+}
+
+ComponentCarrierBaseStation::ComponentCarrierBaseStation ()
+{
+  NS_LOG_FUNCTION (this);
+}
+
+ComponentCarrierBaseStation::~ComponentCarrierBaseStation (void)
+{
+  NS_LOG_FUNCTION (this);
+}
+
+uint16_t
+ComponentCarrierBaseStation::GetCellId ()
+{
+  return m_cellId;
+}
+
+void
+ComponentCarrierBaseStation::SetCellId (uint16_t cellId)
+{
+  NS_LOG_FUNCTION (this << cellId);
+  m_cellId = cellId;
+}
+
 } // namespace ns3
 
 
diff --git a/src/lte/model/component-carrier-enb.h b/src/lte/model/component-carrier-enb.h
index ec381268c..da8780938 100644
--- a/src/lte/model/component-carrier-enb.h
+++ b/src/lte/model/component-carrier-enb.h
@@ -45,7 +45,7 @@ class LteFfrAlgorithm;
  * LteEnbMac, LteFfrAlgorithm, and FfMacScheduler objects.
  *
  */
-class ComponentCarrierEnb : public ComponentCarrier
+class ComponentCarrierEnb : public ComponentCarrierBaseStation
 {
 public:
   /**
@@ -59,12 +59,6 @@ public:
   virtual ~ComponentCarrierEnb (void);
   virtual void DoDispose (void);
 
-  /**
-   * Get cell identifier
-   * \return cell identifier
-   */
-  uint16_t GetCellId ();
-
   /**
    * \return a pointer to the physical layer.
    */
@@ -85,12 +79,6 @@ public:
    */
   Ptr<FfMacScheduler> GetFfMacScheduler ();
 
-  /**
-   * Set physical cell identifier
-   * \param cellId cell identifier
-   */
-  void SetCellId (uint16_t cellId);
-
   /**
    * Set the LteEnbPhy
    * \param s a pointer to the LteEnbPhy
@@ -119,18 +107,12 @@ protected:
   virtual void DoInitialize (void);
 
 private:
-
-  uint16_t m_cellId; ///< Cell identifier
   Ptr<LteEnbPhy> m_phy; ///< the Phy instance of this eNodeB component carrier
   Ptr<LteEnbMac> m_mac; ///< the MAC instance of this eNodeB component carrier
   Ptr<FfMacScheduler> m_scheduler; ///< the scheduler instance of this eNodeB component carrier
   Ptr<LteFfrAlgorithm> m_ffrAlgorithm; ///< the FFR algorithm instance of this eNodeB component carrier
- 
-
 };
 
 } // namespace ns3
 
-
-
 #endif /* COMPONENT_CARRIER_H */
diff --git a/src/lte/model/component-carrier.h b/src/lte/model/component-carrier.h
index c421ef94b..6944e9eb3 100644
--- a/src/lte/model/component-carrier.h
+++ b/src/lte/model/component-carrier.h
@@ -35,12 +35,11 @@ namespace ns3 {
  * \ingroup lte
  *
  * ComponentCarrier Object, it defines a single Carrier
- * This is the parent class for both ComponentCarrierEnb
+ * This is the parent class for both ComponentCarrierBaseStation
  * and ComponentCarrierUe.
  * This class contains the main physical configuration
  * parameters for a carrier. Does not contain pointers to
  * the MAC/PHY objects of the carrier.
-
  */
 class ComponentCarrier : public Object
 {
@@ -64,7 +63,7 @@ public:
   /**
    * \param bw the uplink bandwidth in RBs
    */
-  void SetUlBandwidth (uint8_t bw);
+  virtual void SetUlBandwidth (uint8_t bw);
 
   /**
    * \return the downlink bandwidth in RBs
@@ -74,7 +73,7 @@ public:
   /**
    * \param bw the downlink bandwidth in RBs
    */
-  void SetDlBandwidth (uint8_t bw);
+  virtual void SetDlBandwidth (uint8_t bw);
 
   /**
    * \return the downlink carrier frequency (EARFCN)
@@ -172,7 +171,40 @@ protected:
 
 };
 
+/**
+ * \ingroup lte
+ *
+ * Defines a Base station, that is a ComponentCarrier but with a cell Id.
+ *
+ */
+class ComponentCarrierBaseStation : public ComponentCarrier
+{
+public:
+  /**
+   * \brief Get the type ID.
+   * \return the object TypeId
+   */
+  static TypeId GetTypeId (void);
 
+  ComponentCarrierBaseStation ();
+
+  virtual ~ComponentCarrierBaseStation (void);
+
+  /**
+   * Get cell identifier
+   * \return cell identifier
+   */
+  uint16_t GetCellId ();
+
+  /**
+   * Set physical cell identifier
+   * \param cellId cell identifier
+   */
+  void SetCellId (uint16_t cellId);
+
+protected:
+  uint16_t m_cellId; ///< Cell identifier
+};
 
 } // namespace ns3
 
diff --git a/src/lte/model/eps-bearer.cc b/src/lte/model/eps-bearer.cc
index aa3c47e81..825ecf40d 100644
--- a/src/lte/model/eps-bearer.cc
+++ b/src/lte/model/eps-bearer.cc
@@ -18,14 +18,13 @@
  * Author: Nicola Baldo <nbaldo@cttc.es>
  */
 
-
 #include "eps-bearer.h"
-
 #include <ns3/fatal-error.h>
-
+#include <ns3/attribute-construction-list.h>
 
 namespace ns3 {
 
+NS_OBJECT_ENSURE_REGISTERED (EpsBearer);
 
 GbrQosInformation::GbrQosInformation ()
   : gbrDl (0),
@@ -42,134 +41,166 @@ AllocationRetentionPriority::AllocationRetentionPriority ()
 {
 }
 
-EpsBearer::EpsBearer ()
-  : qci (NGBR_VIDEO_TCP_DEFAULT)
+TypeId
+EpsBearer::GetTypeId (void)
 {
+  static TypeId tid = TypeId ("ns3::EpsBearer")
+    .SetParent<ObjectBase> ()
+    .SetGroupName("Lte")
+    .AddConstructor<EpsBearer> ()
+    .AddAttribute ("Release", "Change from 11 to 15 if you need bearer definition as per Release 15."
+                   " Reference document: TS 23.203. The change does not impact other LTE code than "
+                   " bearers definition.",
+                   UintegerValue (11),
+                   MakeUintegerAccessor (&EpsBearer::GetRelease,
+                                         &EpsBearer::SetRelease),
+                   MakeUintegerChecker<uint32_t> ())
+  ;
+  return tid;
+}
+
+TypeId
+EpsBearer::GetInstanceTypeId () const
+{
+  return EpsBearer::GetTypeId ();
+}
+
+EpsBearer::EpsBearer ()
+  : ObjectBase (),
+    qci (NGBR_VIDEO_TCP_DEFAULT)
+{
+
+  ObjectBase::ConstructSelf (AttributeConstructionList ());
 }
 
 EpsBearer::EpsBearer (Qci x)
-  : qci (x)
+  : ObjectBase (),
+    qci (x)
 {
+  ObjectBase::ConstructSelf (AttributeConstructionList ());
 }
 
 EpsBearer::EpsBearer (Qci x, struct GbrQosInformation y)
-  : qci (x), gbrQosInfo (y)
+  : ObjectBase (),
+    qci (x), gbrQosInfo (y)
 {
+  ObjectBase::ConstructSelf (AttributeConstructionList ());
+}
+
+EpsBearer::EpsBearer (const EpsBearer &o) : ObjectBase (o)
+{
+  qci = o.qci;
+  gbrQosInfo = o.gbrQosInfo;
+  ObjectBase::ConstructSelf (AttributeConstructionList ());
+}
+
+void
+EpsBearer::SetRelease(uint8_t release)
+{
+  switch (release)
+    {
+    case 8:
+    case 9:
+    case 10:
+    case 11:
+      m_requirements = GetRequirementsRel11 ();
+      break;
+    case 15:
+      m_requirements = GetRequirementsRel15 ();
+      break;
+    default:
+      NS_FATAL_ERROR ("Not recognized release " << static_cast<uint32_t> (release) <<
+                      " please use a value between 8 and 11, or 15");
+    }
+  m_release = release;
 }
 
 bool
 EpsBearer::IsGbr () const
 {
-  // 3GPP 23.203 Section 6.1.7.2
-  switch (qci)
-    {
-    case GBR_CONV_VOICE:
-    case GBR_CONV_VIDEO:
-    case GBR_GAMING:
-    case GBR_NON_CONV_VIDEO:
-      return true;
-    case NGBR_IMS:
-    case NGBR_VIDEO_TCP_OPERATOR:
-    case NGBR_VOICE_VIDEO_GAMING:
-    case NGBR_VIDEO_TCP_PREMIUM:
-    case NGBR_VIDEO_TCP_DEFAULT:
-      return false;
-    default:
-      NS_FATAL_ERROR ("unknown QCI value " << qci);
-      return false;
-    }
+  return IsGbr (*m_requirements, qci);
 }
 
 uint8_t
 EpsBearer::GetPriority () const
 {
-  // 3GPP 23.203 Section 6.1.7.2
-  switch (qci)
-    {
-    case GBR_CONV_VOICE:
-      return 2;
-    case GBR_CONV_VIDEO:
-      return 4;
-    case GBR_GAMING:
-      return 3;
-    case GBR_NON_CONV_VIDEO:
-      return 5;
-    case NGBR_IMS:
-      return 1;
-    case NGBR_VIDEO_TCP_OPERATOR:
-      return 6;
-    case NGBR_VOICE_VIDEO_GAMING:
-      return 7;
-    case NGBR_VIDEO_TCP_PREMIUM:
-      return 8;
-    case NGBR_VIDEO_TCP_DEFAULT:
-      return 9;
-    default:
-      NS_FATAL_ERROR ("unknown QCI value " << qci);
-      return 0;
-    }
+  return GetPriority (*m_requirements, qci);
 }
 
 uint16_t
 EpsBearer::GetPacketDelayBudgetMs () const
 {
-  // 3GPP 23.203 Section 6.1.7.2
-  switch (qci)
-    {
-    case GBR_CONV_VOICE:
-      return 100;
-    case GBR_CONV_VIDEO:
-      return 150;
-    case GBR_GAMING:
-      return 50;
-    case GBR_NON_CONV_VIDEO:
-      return 300;
-    case NGBR_IMS:
-      return 100;
-    case NGBR_VIDEO_TCP_OPERATOR:
-      return 300;
-    case NGBR_VOICE_VIDEO_GAMING:
-      return 100;
-    case NGBR_VIDEO_TCP_PREMIUM:
-      return 300;
-    case NGBR_VIDEO_TCP_DEFAULT:
-      return 300;
-    default:
-      NS_FATAL_ERROR ("unknown QCI value " << qci);
-      return 0;
-    }
+  return GetPacketDelayBudgetMs (*m_requirements, qci);
 }
 
 double
 EpsBearer::GetPacketErrorLossRate () const
 {
-  // 3GPP 23.203 Section 6.1.7.2
-  switch (qci)
-    {
-    case GBR_CONV_VOICE:
-      return 1.0e-2;
-    case GBR_CONV_VIDEO:
-      return 1.0e-3;
-    case GBR_GAMING:
-      return 1.0e-3;
-    case GBR_NON_CONV_VIDEO:
-      return 1.0e-6;
-    case NGBR_IMS:
-      return 1.0e-6;
-    case NGBR_VIDEO_TCP_OPERATOR:
-      return 1.0e-6;
-    case NGBR_VOICE_VIDEO_GAMING:
-      return 1.0e-3;
-    case NGBR_VIDEO_TCP_PREMIUM:
-      return 1.0e-6;
-    case NGBR_VIDEO_TCP_DEFAULT:
-      return 1.0e-6;
-    default:
-      NS_FATAL_ERROR ("unknown QCI value " << qci);
-      return 0;
-    }
+  return GetPacketErrorLossRate (*m_requirements, qci);
 }
 
+EpsBearer::BearerRequirementsMap *
+EpsBearer::GetRequirementsRel11 ()
+{
+  /* Needed to support GCC 4.9. Otherwise, use list constructors, for example:
+   * EpsBearer::BearerRequirementsMap
+   * EpsBearer::GetRequirementsRel15 ()
+   * {
+   *   return
+   *     {
+   *       { GBR_CONV_VOICE          , { true,  20, 100, 1.0e-2,    0, 2000} },
+   *       ...
+   *     };
+   * }
+   */
+  static EpsBearer::BearerRequirementsMap ret;
 
+  if (ret.size () == 0)
+    {
+      ret.insert (std::make_pair (GBR_CONV_VOICE,          std::make_tuple (true,  2, 100, 1.0e-2,    0,    0)));
+      ret.insert (std::make_pair (GBR_CONV_VIDEO,          std::make_tuple (true,  4, 150, 1.0e-3,    0,    0)));
+      ret.insert (std::make_pair (GBR_GAMING,              std::make_tuple (true,  3,  50, 1.0e-3,    0,    0)));
+      ret.insert (std::make_pair (GBR_NON_CONV_VIDEO,      std::make_tuple (true,  5, 300, 1.0e-6,    0,    0)));
+      ret.insert (std::make_pair (NGBR_IMS,                std::make_tuple (false, 1, 100, 1.0e-6,    0,    0)));
+      ret.insert (std::make_pair (NGBR_VIDEO_TCP_OPERATOR, std::make_tuple (false, 6, 300, 1.0e-6,    0,    0)));
+      ret.insert (std::make_pair (NGBR_VOICE_VIDEO_GAMING, std::make_tuple (false, 7, 100, 1.0e-3,    0,    0)));
+      ret.insert (std::make_pair (NGBR_VIDEO_TCP_PREMIUM,  std::make_tuple (false, 8, 300, 1.0e-6,    0,    0)));
+      ret.insert (std::make_pair (NGBR_VIDEO_TCP_DEFAULT,  std::make_tuple (false, 9, 300, 1.0e-6,    0,    0)));
+    }
+  return &ret;
+}
+
+EpsBearer::BearerRequirementsMap *
+EpsBearer::GetRequirementsRel15 ()
+{
+  // Needed to support GCC 4.9. Otherwise, use list constructors (see GetRequirementsRel10)
+  static EpsBearer::BearerRequirementsMap ret;
+
+  if (ret.size () == 0)
+    {
+      ret.insert (std::make_pair (GBR_CONV_VOICE,          std::make_tuple (true,  20, 100, 1.0e-2,    0, 2000)));
+      ret.insert (std::make_pair (GBR_CONV_VIDEO,          std::make_tuple (true,  40, 150, 1.0e-3,    0, 2000)));
+      ret.insert (std::make_pair (GBR_GAMING,              std::make_tuple (true,  30,  50, 1.0e-3,    0, 2000)));
+      ret.insert (std::make_pair (GBR_NON_CONV_VIDEO,      std::make_tuple (true,  50, 300, 1.0e-6,    0, 2000)));
+      ret.insert (std::make_pair (GBR_MC_PUSH_TO_TALK,     std::make_tuple (true,   7,  75, 1.0e-2,    0, 2000)));
+      ret.insert (std::make_pair (GBR_NMC_PUSH_TO_TALK,    std::make_tuple (true,  20, 100, 1.0e-2,    0, 2000)));
+      ret.insert (std::make_pair (GBR_MC_VIDEO,            std::make_tuple (true,  15, 100, 1.0e-3,    0, 2000)));
+      ret.insert (std::make_pair (GBR_V2X,                 std::make_tuple (true,  25,  50, 1.0e-2,    0, 2000)));
+      ret.insert (std::make_pair (NGBR_IMS,                std::make_tuple (false, 10, 100, 1.0e-6,    0,    0)));
+      ret.insert (std::make_pair (NGBR_VIDEO_TCP_OPERATOR, std::make_tuple (false, 60, 300, 1.0e-6,    0,    0)));
+      ret.insert (std::make_pair (NGBR_VOICE_VIDEO_GAMING, std::make_tuple (false, 70, 100, 1.0e-3,    0,    0)));
+      ret.insert (std::make_pair (NGBR_VIDEO_TCP_PREMIUM,  std::make_tuple (false, 80, 300, 1.0e-6,    0,    0)));
+      ret.insert (std::make_pair (NGBR_VIDEO_TCP_DEFAULT,  std::make_tuple (false, 90, 300, 1.0e-6,    0,    0)));
+      ret.insert (std::make_pair (NGBR_MC_DELAY_SIGNAL,    std::make_tuple (false,  5,  60, 1.0e-6,    0,    0)));
+      ret.insert (std::make_pair (NGBR_MC_DATA,            std::make_tuple (false, 55, 200, 1.0e-6,    0,    0)));
+      ret.insert (std::make_pair (NGBR_V2X,                std::make_tuple (false, 65,   5, 1.0e-2,    0,    0)));
+      ret.insert (std::make_pair (NGBR_LOW_LAT_EMBB,       std::make_tuple (false, 68,  10, 1.0e-6,    0,    0)));
+      ret.insert (std::make_pair (DGBR_DISCRETE_AUT_SMALL, std::make_tuple (false, 19,  10, 1.0e-4,  255, 2000)));
+      ret.insert (std::make_pair (DGBR_DISCRETE_AUT_LARGE, std::make_tuple (false, 22,  10, 1.0e-4, 1358, 2000)));
+      ret.insert (std::make_pair (DGBR_ITS,                std::make_tuple (false, 24,  30, 1.0e-5, 1354, 2000)));
+      ret.insert (std::make_pair (DGBR_ELECTRICITY,        std::make_tuple (false, 21,  5,  1.0e-5,  255, 2000)));
+    }
+  return &ret;
+}
 
 } // namespace ns3
diff --git a/src/lte/model/eps-bearer.h b/src/lte/model/eps-bearer.h
index c0bb27d58..604759a84 100644
--- a/src/lte/model/eps-bearer.h
+++ b/src/lte/model/eps-bearer.h
@@ -23,6 +23,8 @@
 #define EPS_BEARER
 
 #include <ns3/uinteger.h>
+#include <ns3/object-base.h>
+#include <unordered_map>
 
 namespace ns3 {
 
@@ -60,31 +62,70 @@ struct AllocationRetentionPriority
 };
 
 /**
- * This class contains the specification of EPS Bearers.
+ * \brief This class contains the specification of EPS Bearers.
  *
  * See the following references:
  * 3GPP TS 23.203, Section 4.7.2 The EPS bearer
  * 3GPP TS 23.203, Section 4.7.3 Bearer level QoS parameters
  * 3GPP TS 36.413 Section 9.2.1.15 E-RAB Level QoS Parameters
  *
+ * It supports the selection of different specifications depending on the
+ * release. To change the release, change the attribute "Release". Please remember
+ * that we must expose to all releases the most recent Qci. Asking for Qci parameters
+ * for a release in which it has not been created will result in a crash.
+ *
+ * For example, if you select Release 11 (or if you don't select anything, as
+ * it is the default selection) and then ask for the packet error rate of
+ * the NGBR_MC_DELAY_SIGNAL Qci, the program will crash.
+ *
+ * Please note that from Release 8 (the latest when the LENA project finished)
+ * to Release 11, the bearers ID and requirements are the same. From Release 12,
+ * they started to change, and the latest version is now Release 15. However,
+ * we do not support intermediate types: in other words, you can select from
+ * Release 8 to Release 11, or Release 15. Any other value will result in a
+ * program crash.
+ *
+ * The release version only affect Bearer definitions. Other part of the LTE
+ * module are not affected when changing the Release attribute.
  */
-struct EpsBearer
+class EpsBearer : public ObjectBase
 {
+public:
+  /**
+   * \brief Get the type ID.
+   * \return the object TypeId
+   */
+  static TypeId GetTypeId (void);
+
+  virtual TypeId GetInstanceTypeId (void) const override;
 
   /**
    * QoS Class Indicator. See 3GPP 23.203 Section 6.1.7.2 for standard values.
+   * Updated to Release 15.
    */
-  enum Qci
+  enum Qci : uint8_t
   {
-    GBR_CONV_VOICE          = 1,
-    GBR_CONV_VIDEO          = 2,
-    GBR_GAMING              = 3,
-    GBR_NON_CONV_VIDEO      = 4,
-    NGBR_IMS                = 5,
-    NGBR_VIDEO_TCP_OPERATOR = 6,
-    NGBR_VOICE_VIDEO_GAMING = 7,
-    NGBR_VIDEO_TCP_PREMIUM  = 8,
-    NGBR_VIDEO_TCP_DEFAULT  = 9,
+    GBR_CONV_VOICE          = 1,    ///< GBR Conversational Voice
+    GBR_CONV_VIDEO          = 2,    ///< GBR Conversational Video (Live streaming)
+    GBR_GAMING              = 3,    ///< GBR Real Time Gaming
+    GBR_NON_CONV_VIDEO      = 4,    ///< GBR Non-Conversational Video (Buffered Streaming)
+    GBR_MC_PUSH_TO_TALK     = 65,   ///< GBR Mission Critical User Plane Push To Talk voice
+    GBR_NMC_PUSH_TO_TALK    = 66,   ///< GBR Non-Mission-Critical User Plane Push To Talk voice
+    GBR_MC_VIDEO            = 67,   ///< GBR Mission Critical Video User Plane
+    GBR_V2X                 = 75,   ///< GBR V2X Messages
+    NGBR_IMS                = 5,    ///< Non-GBR IMS Signalling
+    NGBR_VIDEO_TCP_OPERATOR = 6,    ///< Non-GBR TCP-based Video (Buffered Streaming, e.g., www, e-mail...)
+    NGBR_VOICE_VIDEO_GAMING = 7,    ///< Non-GBR Voice, Video, Interactive Streaming
+    NGBR_VIDEO_TCP_PREMIUM  = 8,    ///< Non-GBR TCP-based Video (Buffered Streaming, e.g., www, e-mail...)
+    NGBR_VIDEO_TCP_DEFAULT  = 9,    ///< Non-GBR TCP-based Video (Buffered Streaming, e.g., www, e-mail...)
+    NGBR_MC_DELAY_SIGNAL    = 69,   ///< Non-GBR Mission Critical Delay Sensitive Signalling (e.g., MC-PTT)
+    NGBR_MC_DATA            = 70,   ///< Non-GBR Mission Critical Data
+    NGBR_V2X                = 79,   ///< Non-GBR V2X Messages
+    NGBR_LOW_LAT_EMBB       = 80,   ///< Non-GBR Low Latency eMBB applications
+    DGBR_DISCRETE_AUT_SMALL = 82,   ///< Delay-Critical GBR Discrete Automation Small Packets (TS 22.261)
+    DGBR_DISCRETE_AUT_LARGE = 83,   ///< Delay-Critical GBR Discrete Automation Large Packets (TS 22.261)
+    DGBR_ITS                = 84,   ///< Delay-Critical GBR Intelligent Transport Systems (TS 22.261)
+    DGBR_ELECTRICITY        = 85,   ///< Delay-Critical GBR Electricity Distribution High Voltage (TS 22.261)
   } qci; ///< Qos class indicator
 
   GbrQosInformation gbrQosInfo; ///< GBR QOS information
@@ -111,6 +152,37 @@ struct EpsBearer
    */
   EpsBearer (Qci x, GbrQosInformation y);
 
+  /**
+   * \brief EpsBearer copy constructor
+   * \param o other instance
+   */
+  EpsBearer (const EpsBearer &o);
+
+  /**
+    * \brief Deconstructor
+    */
+  virtual ~EpsBearer () { }
+
+  /**
+   * \brief SetRelease
+   * \param release The release the user want for this bearer
+   *
+   * Releases introduces new types, and change values for existing ones.
+   * While we can't do much for the added type (we must expose them even
+   * if the user want to work with older releases) by calling this method
+   * we can, at least, select the specific parameters value the bearer returns.
+   *
+   * For instance, if the user select release 10 (the default) the priority
+   * of CONV_VIDEO will be 2. With release 15, such priority will be 20.
+   */
+  void SetRelease (uint8_t release);
+
+  /**
+   * \brief GetRelease
+   * \return The release currently set for this bearer type
+   */
+  uint8_t GetRelease () const { return m_release; }
+
   /**
    *
    * @return true if the EPS Bearer is a Guaranteed Bit Rate bearer, false otherwise
@@ -139,6 +211,119 @@ struct EpsBearer
    */
   double  GetPacketErrorLossRate () const;
 
+private:
+  /**
+   * \brief Hashing QCI
+   *
+   * Qci are just uint8_t, so that's how we calculate the hash. Unfortunately,
+   * we have to provide this struct because gcc 4.9 would not compile otherwise.
+   */
+  struct QciHash
+  {
+    /**
+     * \brief Hash the QCI like a normal uint8_t
+     * \param s Qci to hash
+     * \return Hash of Qci
+     */
+    std::size_t
+    operator () (Qci const& s) const noexcept
+      {
+        return std::hash<uint8_t> {} (s);
+      }
+  };
+
+  /**
+    * \brief Map between QCI and requirements
+    *
+    * The tuple is formed by: isGbr, priority, packet delay budget, packet error rate,
+    *  default maximum data burst, default averaging window (0 when does not apply)
+    */
+  typedef std::unordered_map<Qci, std::tuple<bool, uint8_t, uint16_t, double, uint32_t, uint32_t>, QciHash > BearerRequirementsMap;
+
+  /**
+   * \brief Is the selected QCI GBR?
+   * \param map Map between QCI and requirements
+   * \param qci QCI to look for
+   * \return GBR flag for the selected CQI
+   */
+  static uint32_t
+  IsGbr (const BearerRequirementsMap &map, Qci qci) {return std::get<0> (map.at (qci));}
+
+  /**
+   * \brief Get priority for the selected QCI
+   * \param map Map between QCI and requirements
+   * \param qci QCI to look for
+   * \return priority for the selected QCI
+   */
+  static uint8_t
+  GetPriority (const BearerRequirementsMap &map, Qci qci) {return std::get<1> (map.at (qci));}
+  /**
+   * \brief Get packet delay in ms for the selected QCI
+   * \param map Map between QCI and requirements
+   * \param qci QCI to look for
+   * \return packet delay in ms for the selected QCI
+   */
+  static uint16_t
+  GetPacketDelayBudgetMs (const BearerRequirementsMap &map, Qci qci) {return std::get<2> (map.at (qci));}
+  /**
+   * \brief Get packet error rate for the selected QCI
+   * \param map Map between QCI and requirements
+   * \param qci QCI to look for
+   * \return packet error rate for the selected QCI
+   */
+  static double
+  GetPacketErrorLossRate (const BearerRequirementsMap &map, Qci qci) {return std::get<3> (map.at (qci));}
+  /**
+   * \brief Get maximum data burst for the selected QCI
+   * \param map Map between QCI and requirements
+   * \param qci QCI to look for
+   * \return maximum data burst for the selected QCI
+   */
+  static uint32_t
+  GetMaxDataBurst (const BearerRequirementsMap &map, Qci qci) {return std::get<4> (map.at (qci));}
+  /**
+   * \brief Get default averaging window for the selected QCI
+   * \param map Map between QCI and requirements
+   * \param qci QCI to look for
+   * \return default averaging window for the selected QCI
+   */
+  static uint32_t
+  GetAvgWindow (const BearerRequirementsMap &map, Qci qci) {return std::get<5> (map.at (qci));}
+
+  /**
+   * \brief Retrieve requirements for Rel. 11
+   * \return the BearerRequirementsMap for Release 11
+   *
+   * It returns a pointer to a non-const static data. That is not thread-safe,
+   * nor safe to do in general. However, a const-correct version would have
+   * to initialize two static maps, and then returning either one or the other.
+   * But that's a huge memory increase, and EpsBearer is used everywhere.
+   *
+   * To be revisited when GCC 4.9 will not be supported anymore.
+   */
+  static BearerRequirementsMap * GetRequirementsRel11 ();
+
+  /**
+   * \brief Retrieve requirements for Rel. 15
+   * \return the BearerRequirementsMap for Release 15
+   *
+   * It returns a pointer to a non-const static data. That is not thread-safe,
+   * nor safe to do in general. However, a const-correct version would have
+   * to initialize two static maps, and then returning either one or the other.
+   * But that's a huge memory increase, and EpsBearer is used everywhere.
+   *
+   * To be revisited when GCC 4.9 will not be supported anymore.
+   */
+  static BearerRequirementsMap * GetRequirementsRel15 ();
+
+  /**
+    * \brief Requirements pointer per bearer
+    *
+    * It will point to a static map.
+    */
+  BearerRequirementsMap *m_requirements;
+
+  uint8_t m_release {30}; //!< Release (10 or 15)
 };
 
 } // namespace ns3
diff --git a/src/lte/model/lte-ccm-mac-sap.h b/src/lte/model/lte-ccm-mac-sap.h
index 6bb3cc3f6..ba7bc9646 100644
--- a/src/lte/model/lte-ccm-mac-sap.h
+++ b/src/lte/model/lte-ccm-mac-sap.h
@@ -53,6 +53,14 @@ public:
    */
   virtual void ReportMacCeToScheduler (MacCeListElement_s bsr) = 0;
 
+  /**
+   * \brief Report SR to the right scheduler
+   * \param rnti RNTI of the user that requested the SR
+   *
+   * \see LteCcmMacSapUser::UlReceiveSr
+   */
+  virtual void ReportSrToScheduler (uint16_t rnti) = 0;
+
 }; // end of class LteCcmMacSapProvider
 
 
@@ -79,6 +87,20 @@ public:
    */
   virtual void UlReceiveMacCe (MacCeListElement_s bsr, uint8_t componentCarrierId) = 0;
 
+  /**
+   * \brief The MAC received a SR
+   * \param rnti RNTI of the UE that requested a SR
+   * \param componentCarrierId CC that received the SR
+   *
+   * NOTE: Not implemented in the LTE module. The FemtoForum API requires
+   * that this function gets as parameter a struct  SchedUlSrInfoReqParameters.
+   * However, that struct has the SfnSf as a member: since it differs from
+   * LTE to mmwave/NR, and we don't have an effective strategy to deal with
+   * that, we limit the function to the only thing that the module have in
+   * common: the RNTI.
+   */
+  virtual void UlReceiveSr (uint16_t rnti, uint8_t componentCarrierId) = 0;
+
   /**
    * \brief Notifies component carrier manager about physical resource block occupancy
    * \param prbOccupancy The physical resource block occupancy
@@ -100,7 +122,8 @@ public:
    */
   MemberLteCcmMacSapProvider (C* owner);
   // inherited from LteCcmRrcSapProvider
-  virtual void ReportMacCeToScheduler (MacCeListElement_s bsr);
+  virtual void ReportMacCeToScheduler (MacCeListElement_s bsr) override;
+  virtual void ReportSrToScheduler (uint16_t rnti) override;
 
 private:
   C* m_owner; ///< the owner class
@@ -118,6 +141,11 @@ void MemberLteCcmMacSapProvider<C>::ReportMacCeToScheduler (MacCeListElement_s b
   m_owner->DoReportMacCeToScheduler (bsr);
 }
 
+template <class C>
+void MemberLteCcmMacSapProvider<C>::ReportSrToScheduler (uint16_t rnti)
+{
+  m_owner->DoReportSrToScheduler (rnti);
+}
 
 /// MemberLteCcmMacSapUser class
 template <class C>
@@ -132,6 +160,7 @@ public:
   MemberLteCcmMacSapUser (C* owner);
   // inherited from LteCcmRrcSapUser
   virtual void UlReceiveMacCe (MacCeListElement_s bsr, uint8_t componentCarrierId);
+  virtual void UlReceiveSr (uint16_t rnti, uint8_t componentCarrierId);
   virtual void NotifyPrbOccupancy (double prbOccupancy, uint8_t componentCarrierId);
   // inherited from LteMacSapUser
   virtual void NotifyTxOpportunity (LteMacSapUser::TxOpportunityParameters txOpParams);
@@ -155,6 +184,12 @@ void MemberLteCcmMacSapUser<C>::UlReceiveMacCe (MacCeListElement_s bsr, uint8_t
   m_owner->DoUlReceiveMacCe (bsr, componentCarrierId);
 }
 
+template<class C>
+void MemberLteCcmMacSapUser<C>::UlReceiveSr (uint16_t rnti, uint8_t componentCarrierId)
+{
+  m_owner->DoUlReceiveSr (rnti, componentCarrierId);
+}
+
 template <class C>
 void MemberLteCcmMacSapUser<C>::NotifyPrbOccupancy (double prbOccupancy, uint8_t componentCarrierId)
 {
diff --git a/src/lte/model/lte-enb-mac.h b/src/lte/model/lte-enb-mac.h
index d15ee6094..f25a65933 100644
--- a/src/lte/model/lte-enb-mac.h
+++ b/src/lte/model/lte-enb-mac.h
@@ -343,6 +343,17 @@ private:
    * \param bsr the BSR
    */
   void DoReportMacCeToScheduler (MacCeListElement_s bsr);
+
+  /**
+   * \brief Report SR to scheduler
+   * \param rnti RNTI of the UE that requested the SR
+   *
+   * Since SR is not implemented in LTE, this method does nothing.
+   */
+  void DoReportSrToScheduler (uint16_t rnti)
+  {
+    NS_UNUSED (rnti);
+  }
   
 public:
   /**
diff --git a/src/lte/model/lte-enb-net-device.cc b/src/lte/model/lte-enb-net-device.cc
index 7d6f21f4b..0dd7a7556 100644
--- a/src/lte/model/lte-enb-net-device.cc
+++ b/src/lte/model/lte-enb-net-device.cc
@@ -187,25 +187,25 @@ LteEnbNetDevice::DoDispose ()
 Ptr<LteEnbMac>
 LteEnbNetDevice::GetMac () const
 {
-  return m_ccMap.at (0)->GetMac ();
+  return GetMac (0);
 }
 
 Ptr<LteEnbPhy>
 LteEnbNetDevice::GetPhy () const
 {
-  return m_ccMap.at (0)->GetPhy ();
+  return GetPhy (0);
 }
 
 Ptr<LteEnbMac>
-LteEnbNetDevice::GetMac (uint8_t index) 
+LteEnbNetDevice::GetMac (uint8_t index) const
 {
-  return m_ccMap.at (index)->GetMac ();
+  return DynamicCast<ComponentCarrierEnb> (m_ccMap.at (index))->GetMac ();
 }
 
 Ptr<LteEnbPhy>
-LteEnbNetDevice::GetPhy(uint8_t index)  
+LteEnbNetDevice::GetPhy(uint8_t index) const
 {
-  return m_ccMap.at (index)->GetPhy ();
+  return DynamicCast<ComponentCarrierEnb> (m_ccMap.at (index))->GetPhy ();
 }
 
 Ptr<LteEnbRrc>
@@ -347,14 +347,14 @@ LteEnbNetDevice::SetCsgIndication (bool csgIndication)
   UpdateConfig (); // propagate the change to RRC level
 }
 
-std::map < uint8_t, Ptr<ComponentCarrierEnb> >
-LteEnbNetDevice::GetCcMap ()
+std::map < uint8_t, Ptr<ComponentCarrierBaseStation> >
+LteEnbNetDevice::GetCcMap () const
 {
   return m_ccMap;
 }
 
 void
-LteEnbNetDevice::SetCcMap (std::map< uint8_t, Ptr<ComponentCarrierEnb> > ccm)
+LteEnbNetDevice::SetCcMap (std::map< uint8_t, Ptr<ComponentCarrierBaseStation> > ccm)
 {
   NS_ASSERT_MSG (!m_isConfigured, "attempt to set CC map after configuration");
   m_ccMap = ccm;
@@ -366,8 +366,7 @@ LteEnbNetDevice::DoInitialize (void)
   NS_LOG_FUNCTION (this);
   m_isConstructed = true;
   UpdateConfig ();
-  std::map< uint8_t, Ptr<ComponentCarrierEnb> >::iterator it;
-  for (it = m_ccMap.begin (); it != m_ccMap.end (); ++it)
+  for (auto it = m_ccMap.begin (); it != m_ccMap.end (); ++it)
     {
        it->second->Initialize ();
     }
diff --git a/src/lte/model/lte-enb-net-device.h b/src/lte/model/lte-enb-net-device.h
index 2038d61ce..8d0727ed8 100644
--- a/src/lte/model/lte-enb-net-device.h
+++ b/src/lte/model/lte-enb-net-device.h
@@ -79,7 +79,7 @@ public:
    * \param index CC index
    * \return a pointer to the MAC of the CC addressed by index.
    */
-  Ptr<LteEnbMac> GetMac (uint8_t index);
+  Ptr<LteEnbMac> GetMac (uint8_t index) const;
 
   /**
    * \return a pointer to the physical layer of the PCC.
@@ -90,7 +90,7 @@ public:
    * \param index SCC index
    * \return a pointer to the physical layer of the SCC addressed by index.
    */
-  Ptr<LteEnbPhy> GetPhy (uint8_t index);
+  Ptr<LteEnbPhy> GetPhy (uint8_t index) const;
 
   /** 
    * \return a pointer to the Radio Resource Control instance of the eNB
@@ -204,14 +204,14 @@ public:
    *
    */
 
-  void SetCcMap (std::map< uint8_t, Ptr<ComponentCarrierEnb> > ccm);
+  void SetCcMap (std::map< uint8_t, Ptr<ComponentCarrierBaseStation> > ccm);
 
   /**
    * \returns  The Component Carrier Map of the Enb.
    *
    */
 
-  std::map< uint8_t, Ptr<ComponentCarrierEnb> >  GetCcMap (void);
+  std::map< uint8_t, Ptr<ComponentCarrierBaseStation> >  GetCcMap (void) const;
 
 protected:
   // inherited from Object
@@ -253,7 +253,7 @@ private:
   uint16_t m_csgId; ///< CSG ID
   bool m_csgIndication; ///< CSG indication
 
-  std::map < uint8_t, Ptr<ComponentCarrierEnb> > m_ccMap; /**< ComponentCarrier map */
+  std::map < uint8_t, Ptr<ComponentCarrierBaseStation> > m_ccMap; /**< ComponentCarrier map */
   
   Ptr<LteEnbComponentCarrierManager> m_componentCarrierManager; ///< the component carrier manager of this eNb
 
diff --git a/src/lte/model/lte-enb-rrc.cc b/src/lte/model/lte-enb-rrc.cc
index 2942ff920..a1037a2a2 100644
--- a/src/lte/model/lte-enb-rrc.cc
+++ b/src/lte/model/lte-enb-rrc.cc
@@ -1108,7 +1108,7 @@ UeManager::RecvMeasurementReport (LteRrcSap::MeasurementReport msg)
       m_rrc->m_anrSapProvider->ReportUeMeas (msg.measResults);
     }
 
-  if ((m_rrc->m_ffrRrcSapProvider.at (0) != 0)
+  if ((m_rrc->m_ffrRrcSapProvider.size () > 0)
       && (m_rrc->m_ffrMeasIds.find (measId) != m_rrc->m_ffrMeasIds.end ()))
     {
       // this measurement was requested by the FFR function
@@ -1460,7 +1460,7 @@ UeManager::BuildNonCriticalExtentionConfigurationCa ()
           ccId++;
         }
 
-      Ptr<ComponentCarrierEnb> eNbCcm = it.second;
+      Ptr<ComponentCarrierBaseStation> eNbCcm = it.second;
       LteRrcSap::SCellToAddMod component;
       component.sCellIndex = ccId;
       component.cellIdentification.physCellId = eNbCcm->GetCellId ();
@@ -1545,13 +1545,10 @@ LteEnbRrc::LteEnbRrc ()
   m_s1SapUser = new MemberEpcEnbS1SapUser<LteEnbRrc> (this);
   m_cphySapUser.push_back (new MemberLteEnbCphySapUser<LteEnbRrc> (this));
   m_ccmRrcSapUser = new MemberLteCcmRrcSapUser <LteEnbRrc>(this);
-  m_cphySapProvider.push_back (0);
-  m_cmacSapProvider.push_back (0);
-  m_ffrRrcSapProvider.push_back (0);
 }
 
 void
-LteEnbRrc::ConfigureCarriers (std::map<uint8_t, Ptr<ComponentCarrierEnb>> ccPhyConf)
+LteEnbRrc::ConfigureCarriers (std::map<uint8_t, Ptr<ComponentCarrierBaseStation>> ccPhyConf)
 {
   NS_ASSERT_MSG (!m_carriersConfigured, "Secondary carriers can be configured only once.");
   m_componentCarrierPhyConf = ccPhyConf;
@@ -1563,9 +1560,6 @@ LteEnbRrc::ConfigureCarriers (std::map<uint8_t, Ptr<ComponentCarrierEnb>> ccPhyC
       m_cphySapUser.push_back (new MemberLteEnbCphySapUser<LteEnbRrc> (this));
       m_cmacSapUser.push_back (new EnbRrcMemberLteEnbCmacSapUser (this, i));
       m_ffrRrcSapUser.push_back (new MemberLteFfrRrcSapUser<LteEnbRrc> (this));
-      m_cphySapProvider.push_back (0);
-      m_cmacSapProvider.push_back (0);
-      m_ffrRrcSapProvider.push_back (0);
     }
   m_carriersConfigured = true;
   Object::DoInitialize ();
@@ -1790,7 +1784,15 @@ void
 LteEnbRrc::SetLteEnbCmacSapProvider (LteEnbCmacSapProvider * s, uint8_t pos)
 {
   NS_LOG_FUNCTION (this << s);
-  m_cmacSapProvider.at (pos) = s;
+  if (m_cmacSapProvider.size () > pos)
+    {
+      m_cmacSapProvider.at (pos) = s;
+    }
+  else
+    {
+      m_cmacSapProvider.push_back (s);
+      NS_ABORT_IF (m_cmacSapProvider.size () - 1 != pos);
+    }
 }
 
 LteEnbCmacSapUser*
@@ -1853,14 +1855,33 @@ void
 LteEnbRrc::SetLteFfrRrcSapProvider (LteFfrRrcSapProvider * s)
 {
   NS_LOG_FUNCTION (this << s);
-  m_ffrRrcSapProvider.at (0) = s;
+  if (m_ffrRrcSapProvider.size () > 0)
+    {
+      m_ffrRrcSapProvider.at (0) = s;
+    }
+  else
+    {
+      m_ffrRrcSapProvider.push_back (s);
+    }
+
 }
 
 void
 LteEnbRrc::SetLteFfrRrcSapProvider (LteFfrRrcSapProvider * s, uint8_t index)
 {
   NS_LOG_FUNCTION (this << s);
-  m_ffrRrcSapProvider.at (index) = s;
+  if (m_ffrRrcSapProvider.size () > index)
+    {
+      m_ffrRrcSapProvider.at (index) = s;
+    }
+  else
+    {
+      m_ffrRrcSapProvider.push_back (s);
+      NS_ABORT_MSG_IF (m_ffrRrcSapProvider.size () - 1 != index,
+                       "You meant to store the pointer at position " <<
+                       static_cast<uint32_t> (index) <<
+                       " but it went to " << m_ffrRrcSapProvider.size () - 1);
+    }
 }
 
 LteFfrRrcSapUser*
@@ -1916,7 +1937,14 @@ void
 LteEnbRrc::SetLteEnbCphySapProvider (LteEnbCphySapProvider * s)
 {
   NS_LOG_FUNCTION (this << s);
-  m_cphySapProvider.at(0) = s;
+  if (m_cphySapProvider.size () > 0)
+    {
+      m_cphySapProvider.at (0) = s;
+    }
+  else
+    {
+      m_cphySapProvider.push_back (s);
+    }
 }
 
 LteEnbCphySapUser*
@@ -1930,7 +1958,15 @@ void
 LteEnbRrc::SetLteEnbCphySapProvider (LteEnbCphySapProvider * s, uint8_t pos)
 {
   NS_LOG_FUNCTION (this << s);
-  m_cphySapProvider.at(pos) = s;
+  if (m_cphySapProvider.size () > pos)
+    {
+      m_cphySapProvider.at(pos) = s;
+    }
+  else
+    {
+      m_cphySapProvider.push_back (s);
+      NS_ABORT_IF (m_cphySapProvider.size () - 1 != pos);
+    }
 }
 
 LteEnbCphySapUser*
@@ -2047,7 +2083,7 @@ LteEnbRrc::AddUeMeasReportConfig (LteRrcSap::ReportConfigEutra config)
 }
 
 void
-LteEnbRrc::ConfigureCell (std::map<uint8_t, Ptr<ComponentCarrierEnb>> ccPhyConf)
+LteEnbRrc::ConfigureCell (std::map<uint8_t, Ptr<ComponentCarrierBaseStation>> ccPhyConf)
 {
   auto it = ccPhyConf.begin ();
   NS_ASSERT (it != ccPhyConf.end ());
@@ -2065,8 +2101,11 @@ LteEnbRrc::ConfigureCell (std::map<uint8_t, Ptr<ComponentCarrierEnb>> ccPhyConf)
       m_cphySapProvider.at (it.first)->SetEarfcn (it.second->GetUlEarfcn (), it.second->GetDlEarfcn ());
       m_cphySapProvider.at (it.first)->SetCellId (it.second->GetCellId ());
       m_cmacSapProvider.at (it.first)->ConfigureMac (it.second->GetUlBandwidth (), it.second->GetDlBandwidth ());
-      m_ffrRrcSapProvider.at (it.first)->SetCellId (it.second->GetCellId ());
-      m_ffrRrcSapProvider.at (it.first)->SetBandwidth (it.second->GetUlBandwidth (), it.second->GetDlBandwidth ());
+      if (m_ffrRrcSapProvider.size () > it.first)
+        {
+          m_ffrRrcSapProvider.at (it.first)->SetCellId (it.second->GetCellId ());
+          m_ffrRrcSapProvider.at (it.first)->SetBandwidth (it.second->GetUlBandwidth (), it.second->GetDlBandwidth ());
+        }
     }
 
   m_dlEarfcn = dlEarfcn;
@@ -2481,6 +2520,7 @@ LteEnbRrc::DoRecvLoadInformation (EpcX2SapUser::LoadInformationParams params)
 
   NS_LOG_LOGIC ("Number of cellInformationItems = " << params.cellInformationList.size ());
 
+  NS_ABORT_IF (m_ffrRrcSapProvider.size () == 0);
   m_ffrRrcSapProvider.at (0)->RecvLoadInformation (params);
 }
 
diff --git a/src/lte/model/lte-enb-rrc.h b/src/lte/model/lte-enb-rrc.h
index fee531f52..44380fdb1 100644
--- a/src/lte/model/lte-enb-rrc.h
+++ b/src/lte/model/lte-enb-rrc.h
@@ -863,13 +863,13 @@ public:
    *
    * \param ccPhyConf the component carrier configuration
    */
-  void ConfigureCell (std::map<uint8_t, Ptr<ComponentCarrierEnb>> ccPhyConf);
+  void ConfigureCell (std::map<uint8_t, Ptr<ComponentCarrierBaseStation> > ccPhyConf);
 
   /**
    * \brief Configure carriers.
    * \param ccPhyConf the component carrier configuration
    */
-  void ConfigureCarriers (std::map<uint8_t, Ptr<ComponentCarrierEnb>> ccPhyConf);
+  void ConfigureCarriers (std::map<uint8_t, Ptr<ComponentCarrierBaseStation>> ccPhyConf);
 
   /** 
    * set the cell id of this eNB
@@ -1591,7 +1591,7 @@ private:
 
   bool m_carriersConfigured; ///< are carriers configured
 
-  std::map<uint8_t, Ptr<ComponentCarrierEnb>> m_componentCarrierPhyConf; ///< component carrier phy configuration
+  std::map<uint8_t, Ptr<ComponentCarrierBaseStation>> m_componentCarrierPhyConf; ///< component carrier phy configuration
 
 }; // end of `class LteEnbRrc`
 
diff --git a/src/lte/model/lte-mac-sap.h b/src/lte/model/lte-mac-sap.h
index c4ebd3bb6..ed0bd1057 100644
--- a/src/lte/model/lte-mac-sap.h
+++ b/src/lte/model/lte-mac-sap.h
@@ -102,6 +102,30 @@ public:
    */
   struct TxOpportunityParameters
   {
+    /**
+     * \brief TxOpportunityParameters constructor
+     * \param bytes Bytes
+     * \param layer Layer
+     * \param harqId HarqID
+     * \param ccId Component carrier ID
+     * \param rnti RNTI
+     * \param lcId Logical Channel ID
+     */
+    TxOpportunityParameters (uint32_t bytes, uint8_t layer, uint8_t harqId,
+                             uint8_t ccId, uint16_t rnti, uint8_t lcId)
+    {
+      this->bytes = bytes;
+      this->layer = layer;
+      this->harqId = harqId;
+      this->componentCarrierId = ccId;
+      this->rnti = rnti;
+      this->lcid = lcId;
+    }
+    /**
+     * \brief TxOpportunityParameters default constructor (DEPRECATED)
+     */
+    TxOpportunityParameters () { }
+
     uint32_t bytes;  /**< the number of bytes to transmit */
     uint8_t layer; /**<  the layer of transmission (MIMO) */
     uint8_t harqId; /**< the HARQ ID */
@@ -131,6 +155,23 @@ public:
    */
   struct ReceivePduParameters
   {
+    /**
+     * \brief ReceivePduParameters default constructor (DEPRECATED)
+     */
+    ReceivePduParameters () { }
+
+    /**
+     * \brief ReceivePduParameters constructor
+     * \param p Packet
+     * \param rnti RNTI
+     * \param lcid Logical Channel ID
+     */
+    ReceivePduParameters (const Ptr<Packet> &p, uint16_t rnti, uint8_t lcid)
+    {
+      this->p = p;
+      this->rnti = rnti;
+      this->lcid = lcid;
+    }
     Ptr<Packet> p;  /**< the RLC PDU to be received */
     uint16_t rnti; /**< the C-RNTI identifying the UE */
     uint8_t lcid; /**< the logical channel id */
diff --git a/src/lte/model/no-op-component-carrier-manager.cc b/src/lte/model/no-op-component-carrier-manager.cc
index a58fae4f6..59e08989c 100644
--- a/src/lte/model/no-op-component-carrier-manager.cc
+++ b/src/lte/model/no-op-component-carrier-manager.cc
@@ -411,6 +411,18 @@ NoOpComponentCarrierManager::DoUlReceiveMacCe (MacCeListElement_s bsr, uint8_t c
     }
 }
 
+void
+NoOpComponentCarrierManager::DoUlReceiveSr (uint16_t rnti, uint8_t componentCarrierId)
+{
+  NS_LOG_FUNCTION (this);
+
+  auto sapIt = m_ccmMacSapProviderMap.find (componentCarrierId);
+  NS_ABORT_MSG_IF (sapIt == m_ccmMacSapProviderMap.end (),
+                   "Sap not found in the CcmMacSapProviderMap");
+
+  sapIt->second->ReportSrToScheduler (rnti);
+}
+
 
 //////////////////////////////////////////
 
@@ -515,4 +527,21 @@ RrComponentCarrierManager::DoUlReceiveMacCe (MacCeListElement_s bsr, uint8_t com
     }
 }
 
+void
+RrComponentCarrierManager::DoUlReceiveSr(uint16_t rnti, uint8_t componentCarrierId)
+{
+  NS_LOG_FUNCTION (this);
+  NS_UNUSED (componentCarrierId);
+  // split traffic in uplink equally among carriers
+  uint32_t numberOfCarriersForUe = m_enabledComponentCarrier.find (rnti)->second;
+
+  m_ccmMacSapProviderMap.find (m_lastCcIdForSr)->second->ReportSrToScheduler (rnti);
+
+  m_lastCcIdForSr++;
+  if (m_lastCcIdForSr > numberOfCarriersForUe - 1)
+    {
+      m_lastCcIdForSr = 0;
+    }
+}
+
 } // end of namespace ns3
diff --git a/src/lte/model/no-op-component-carrier-manager.h b/src/lte/model/no-op-component-carrier-manager.h
index 9b524c118..6d2fca189 100644
--- a/src/lte/model/no-op-component-carrier-manager.h
+++ b/src/lte/model/no-op-component-carrier-manager.h
@@ -138,6 +138,12 @@ protected:
    * \param componentCarrierId the component carrier ID
    */
   virtual void DoUlReceiveMacCe (MacCeListElement_s bsr, uint8_t componentCarrierId);
+  /**
+   * \brief Forward uplink SR to CCM, called by MAC through CCM SAP interface.
+   * \param rnti RNTI of the UE that requested SR
+   * \param componentCarrierId the component carrier ID that forwarded the SR
+   */
+  virtual void DoUlReceiveSr (uint16_t rnti, uint8_t componentCarrierId);
   /**
    * \brief Function implements the function of the SAP interface of CCM instance which is used by MAC
    * to notify the PRB occupancy reported by scheduler.
@@ -153,7 +159,7 @@ protected:
 }; // end of class NoOpComponentCarrierManager
 
 
-/*
+/**
  * \brief Component carrier manager implementation that splits traffic equally among carriers.
  */
 class RrComponentCarrierManager : public NoOpComponentCarrierManager
@@ -161,7 +167,7 @@ class RrComponentCarrierManager : public NoOpComponentCarrierManager
 public:
 
   RrComponentCarrierManager ();
-  virtual ~RrComponentCarrierManager ();
+  virtual ~RrComponentCarrierManager () override;
   /**
    * \brief Get the type ID.
    * \return the object TypeId
@@ -171,9 +177,12 @@ public:
 protected:
 
   // Inherited methods
-  virtual void DoReportBufferStatus (LteMacSapProvider::ReportBufferStatusParameters params);
-  virtual void DoUlReceiveMacCe (MacCeListElement_s bsr, uint8_t componentCarrierId);
+  virtual void DoReportBufferStatus (LteMacSapProvider::ReportBufferStatusParameters params) override;
+  virtual void DoUlReceiveMacCe (MacCeListElement_s bsr, uint8_t componentCarrierId) override;
+  virtual void DoUlReceiveSr (uint16_t rnti, uint8_t componentCarrierId) override;
 
+private:
+  uint8_t m_lastCcIdForSr {0}; //!< Last CCID to which a SR was routed
 }; // end of class RrComponentCarrierManager
 
 } // end of namespace ns3
diff --git a/src/lte/model/simple-ue-component-carrier-manager.h b/src/lte/model/simple-ue-component-carrier-manager.h
index a9ce82988..621cbdb24 100644
--- a/src/lte/model/simple-ue-component-carrier-manager.h
+++ b/src/lte/model/simple-ue-component-carrier-manager.h
@@ -87,7 +87,7 @@ protected:
    * \brief Report buffer status function
    * \param params LteMacSapProvider::ReportBufferStatusParameters
    */
-  void DoReportBufferStatus (LteMacSapProvider::ReportBufferStatusParameters params);
+  virtual void DoReportBufferStatus (LteMacSapProvider::ReportBufferStatusParameters params);
   /// Notify HARQ deliver failure
   void DoNotifyHarqDeliveryFailure ();
   // forwarded from LteMacSapUser
@@ -111,7 +111,7 @@ protected:
    * \param msu the MSU
    * \returns updated LC config list
    */
-  std::vector<LteUeCcmRrcSapProvider::LcsConfig> DoAddLc (uint8_t lcId,  LteUeCmacSapProvider::LogicalChannelConfig lcConfig, LteMacSapUser* msu);
+  virtual std::vector<LteUeCcmRrcSapProvider::LcsConfig> DoAddLc (uint8_t lcId,  LteUeCmacSapProvider::LogicalChannelConfig lcConfig, LteMacSapUser* msu);
   /**
    * \brief Remove LC function
    * \param lcid the LCID
@@ -125,14 +125,14 @@ protected:
    * \param msu the MSU
    * \returns LteMacSapUser *
    */
-  LteMacSapUser* DoConfigureSignalBearer (uint8_t lcId,  LteUeCmacSapProvider::LogicalChannelConfig lcConfig, LteMacSapUser* msu);
+  virtual LteMacSapUser* DoConfigureSignalBearer (uint8_t lcId,  LteUeCmacSapProvider::LogicalChannelConfig lcConfig, LteMacSapUser* msu);
   /**
    * \brief Reset LC map
    *
    */
   void DoReset ();
   
-private:
+protected:
   
   LteMacSapUser* m_ccmMacSapUser;//!< Interface to the UE RLC instance.
   LteMacSapProvider* m_ccmMacSapProvider; //!< Receive API calls from the UE RLC instance
diff --git a/src/spectrum/model/spectrum-value.cc b/src/spectrum/model/spectrum-value.cc
index b3bcadfd9..525b58d6e 100644
--- a/src/spectrum/model/spectrum-value.cc
+++ b/src/spectrum/model/spectrum-value.cc
@@ -692,8 +692,17 @@ SpectrumValue::operator>> (int n) const
   return res;
 }
 
+uint32_t
+SpectrumValue::GetValuesN () const
+{
+  return m_values.size ();
+}
 
-
+const double &
+SpectrumValue::ValuesAt (uint32_t pos) const
+{
+  return m_values.at (pos);
+}
 
 } // namespace ns3
 
diff --git a/src/spectrum/model/spectrum-value.h b/src/spectrum/model/spectrum-value.h
index dd6c7ac55..73bde05e3 100644
--- a/src/spectrum/model/spectrum-value.h
+++ b/src/spectrum/model/spectrum-value.h
@@ -157,7 +157,18 @@ public:
    */
   Values::iterator ValuesEnd ();
 
+  /**
+   * \brief Get the number of values stored in the array
+   * \return the values array size
+   */
+  uint32_t GetValuesN () const;
 
+  /**
+   * \brief Get the value element at the position
+   * \param pos position
+   * \return the value element in that position (with bounds checking)
+   */
+  const double & ValuesAt (uint32_t pos) const;
 
   /**
    *  addition operator