diff --git a/src/lte/helper/lena-helper.cc b/src/lte/helper/lena-helper.cc
index 7f79028b0..a687bf816 100644
--- a/src/lte/helper/lena-helper.cc
+++ b/src/lte/helper/lena-helper.cc
@@ -272,7 +272,6 @@ LenaHelper::InstallSingleUeDevice (Ptr<Node> n)
   n->AddDevice (dev);
   dlPhy->SetGenericPhyRxEndOkCallback (MakeCallback (&LteUePhy::PhyPduReceived, phy));
 
-  dev->Start ();
   return dev;
 }
 
@@ -306,8 +305,12 @@ LenaHelper::Attach (Ptr<NetDevice> ueDevice, Ptr<NetDevice> enbDevice)
  
   // WILD HACK - should be done through PHY SAP, probably passing by RRC
   uePhy->SetRnti (rnti);
-  uePhy->DoSetBandwidth (enbDevice->GetObject<LteEnbNetDevice> ()->GetUlBandwidth (), 
+  uePhy->DoSetBandwidth (enbDevice->GetObject<LteEnbNetDevice> ()->GetUlBandwidth (),
                          enbDevice->GetObject<LteEnbNetDevice> ()->GetDlBandwidth ());
+  uePhy->DoSetEarfcn (enbDevice->GetObject<LteEnbNetDevice> ()->GetDlEarfcn (),
+                      enbDevice->GetObject<LteEnbNetDevice> ()->GetUlEarfcn ());
+
+  ueDevice->Start ();
 }
 
 
@@ -347,7 +350,7 @@ LenaHelper::EnableLogComponents (void)
   LogComponentEnable ("LtePhy", LOG_LEVEL_ALL);
   LogComponentEnable ("LteEnbPhy", LOG_LEVEL_ALL);
   LogComponentEnable ("LteUePhy", LOG_LEVEL_ALL);
-
+  LogComponentEnable ("LteSpectrumValueHelper", LOG_LEVEL_ALL);
   LogComponentEnable ("LteSpectrumPhy", LOG_LEVEL_ALL);
   LogComponentEnable ("LteInterference", LOG_LEVEL_ALL);
   LogComponentEnable ("LteSinrChunkProcessor", LOG_LEVEL_ALL);
diff --git a/src/lte/model/lte-enb-net-device.cc b/src/lte/model/lte-enb-net-device.cc
index 0f2f2d993..df8b996f4 100644
--- a/src/lte/model/lte-enb-net-device.cc
+++ b/src/lte/model/lte-enb-net-device.cc
@@ -76,13 +76,13 @@ TypeId LteEnbNetDevice::GetTypeId (void)
                    MakePointerAccessor (&LteEnbNetDevice::m_phy),
                    MakePointerChecker <LteEnbPhy> ())
     .AddAttribute ("UlBandwidth",
-                   "Uplink bandwidth in number of Resource Blocks",
+                   "Uplink Transmission Bandwidth Configuration in number of Resource Blocks",
                    UintegerValue (25),
                    MakeUintegerAccessor (&LteEnbNetDevice::SetUlBandwidth, 
                                          &LteEnbNetDevice::GetUlBandwidth),
                    MakeUintegerChecker<uint8_t> ())
     .AddAttribute ("DlBandwidth",
-                   "Downlink bandwidth in number of Resource Blocks",
+                   "Downlink Transmission Bandwidth Configuration in number of Resource Blocks",
                    UintegerValue (25),
                    MakeUintegerAccessor (&LteEnbNetDevice::SetDlBandwidth, 
                                          &LteEnbNetDevice::GetDlBandwidth),
@@ -92,6 +92,18 @@ TypeId LteEnbNetDevice::GetTypeId (void)
                    UintegerValue (0),
                    MakeUintegerAccessor (&LteEnbNetDevice::m_cellId),
                    MakeUintegerChecker<uint16_t> ())
+    .AddAttribute ("DlEarfcn",
+                   "Downlink E-UTRA Absolute Radio Frequency Channel Number (EARFCN) "
+                   "as per 3GPP 36.101 Section 5.7.3. ",  
+                   UintegerValue (100),
+                   MakeUintegerAccessor (&LteEnbNetDevice::m_dlEarfcn),
+                   MakeUintegerChecker<uint16_t> ())
+    .AddAttribute ("UlEarfcn",
+                   "Uplink E-UTRA Absolute Radio Frequency Channel Number (EARFCN) "
+                   "as per 3GPP 36.101 Section 5.7.3. ",  
+                   UintegerValue (18100),
+                   MakeUintegerAccessor (&LteEnbNetDevice::m_ulEarfcn),
+                   MakeUintegerChecker<uint16_t> ())
     ;
   return tid;
 }
@@ -220,11 +232,39 @@ LteEnbNetDevice::SetDlBandwidth (uint8_t bw)
     }
 }
 
+uint16_t 
+LteEnbNetDevice::GetDlEarfcn () const
+{
+  return m_dlEarfcn;
+}
+
+void 
+LteEnbNetDevice::SetDlEarfcn (uint16_t earfcn)
+{ 
+  m_dlEarfcn = earfcn;
+}
+
+uint16_t 
+LteEnbNetDevice::GetUlEarfcn () const
+{
+  return m_ulEarfcn;
+}
+
+void 
+LteEnbNetDevice::SetUlEarfcn (uint16_t earfcn)
+{ 
+  m_ulEarfcn = earfcn;
+}
+
+
 void 
 LteEnbNetDevice::DoStart (void)
 {
   m_cellId = ++m_cellIdCounter;
-  UpdateConfig ();
+  UpdateConfig ();  
+  m_phy->Start ();
+  m_mac->Start ();
+  m_rrc->Start ();
 }
 
 
@@ -274,8 +314,10 @@ LteEnbNetDevice::UpdateConfig (void)
 
   m_rrc->ConfigureCell (m_ulBandwidth, m_dlBandwidth);
 
-  // WILD HACK -  should use the PHY SAP instead. Probably should handle this through the RRC
+  // Configuring directly for now, but ideally we should use the PHY
+  // SAP instead. Probably should handle this through the RRC.  
   m_phy->DoSetBandwidth (m_ulBandwidth, m_dlBandwidth);
+  m_phy->DoSetEarfcn (m_dlEarfcn, m_ulEarfcn);
   m_phy->DoSetCellId (m_cellId);
   
 }
diff --git a/src/lte/model/lte-enb-net-device.h b/src/lte/model/lte-enb-net-device.h
index 684fc5199..33774ff88 100644
--- a/src/lte/model/lte-enb-net-device.h
+++ b/src/lte/model/lte-enb-net-device.h
@@ -105,6 +105,26 @@ public:
    */
   void SetDlBandwidth (uint8_t bw);
 
+  /** 
+   * \return the downlink carrier frequency (EARFCN)
+   */
+  uint16_t GetDlEarfcn () const;
+
+  /** 
+   * \param bw the downlink carrier frequency (EARFCN)
+   */
+  void SetDlEarfcn (uint16_t earfcn);
+
+  /** 
+   * \return the uplink carrier frequency (EARFCN)
+   */
+  uint16_t GetUlEarfcn () const;
+
+  /** 
+   * \param bw the uplink carrier frequency (EARFCN)
+   */
+  void SetUlEarfcn (uint16_t earfcn);
+
 
 protected:
 
@@ -144,6 +164,9 @@ private:
 
   uint8_t m_dlBandwidth; /**< downlink bandwidth in RBs */
   uint8_t m_ulBandwidth; /**< uplink bandwidth in RBs */
+
+  uint16_t m_dlEarfcn;  /**< downlink carrier frequency */ 
+  uint16_t m_ulEarfcn;  /**< uplink carrier frequency */ 
   
 };
 
diff --git a/src/lte/model/lte-enb-phy.cc b/src/lte/model/lte-enb-phy.cc
index 9707fefc4..929eea7ef 100644
--- a/src/lte/model/lte-enb-phy.cc
+++ b/src/lte/model/lte-enb-phy.cc
@@ -158,6 +158,16 @@ LteEnbPhy::DoDispose ()
   LtePhy::DoDispose ();
 }
 
+void
+LteEnbPhy::DoStart ()
+{
+  NS_LOG_FUNCTION (this);
+  Ptr<SpectrumValue> noisePsd = LteSpectrumValueHelper::CreateNoisePowerSpectralDensity (m_ulEarfcn, m_ulBandwidth, m_noiseFigure);
+  m_uplinkSpectrumPhy->SetNoisePowerSpectralDensity (noisePsd);
+  LtePhy::DoStart ();
+}
+
+
 void
 LteEnbPhy::SetLteEnbPhySapUser (LteEnbPhySapUser* s)
 {
@@ -189,8 +199,6 @@ LteEnbPhy::SetNoiseFigure (double nf)
 {
   NS_LOG_FUNCTION (this << nf);
   m_noiseFigure = nf;  
-  Ptr<SpectrumValue> noisePsd = LteSpectrumValueHelper::CreateUplinkNoisePowerSpectralDensity (m_noiseFigure);
-  m_uplinkSpectrumPhy->SetNoisePowerSpectralDensity (noisePsd);
 }
 
 double
@@ -268,8 +276,7 @@ LteEnbPhy::CreateTxPowerSpectralDensity ()
 {
   NS_LOG_FUNCTION (this);
 
-  LteSpectrumValueHelper psdHelper;
-  Ptr<SpectrumValue> psd = psdHelper.CreateDownlinkTxPowerSpectralDensity (GetTxPower (), GetDownlinkSubChannels ());
+  Ptr<SpectrumValue> psd = LteSpectrumValueHelper::CreateTxPowerSpectralDensity (m_dlEarfcn, m_dlBandwidth, m_txPower, GetDownlinkSubChannels ());
 
   return psd;
 }
diff --git a/src/lte/model/lte-enb-phy.h b/src/lte/model/lte-enb-phy.h
index 8b0f1af70..e83be1e22 100644
--- a/src/lte/model/lte-enb-phy.h
+++ b/src/lte/model/lte-enb-phy.h
@@ -57,7 +57,9 @@ public:
   
   virtual ~LteEnbPhy ();
 
+  // inherited from Object
   static TypeId GetTypeId (void);
+  virtual void DoStart (void);
   virtual void DoDispose (void);
 
 
diff --git a/src/lte/model/lte-phy.cc b/src/lte/model/lte-phy.cc
index de3952e91..25d18cb5b 100644
--- a/src/lte/model/lte-phy.cc
+++ b/src/lte/model/lte-phy.cc
@@ -207,6 +207,12 @@ LtePhy::DoSetBandwidth (uint8_t ulBandwidth, uint8_t dlBandwidth)
     }
 }
 
+void 
+LtePhy::DoSetEarfcn (uint16_t dlEarfcn, uint16_t ulEarfcn)
+{
+ m_dlEarfcn = dlEarfcn;
+ m_ulEarfcn = ulEarfcn;
+}
 
 uint8_t
 LtePhy::GetRbgSize (void) const
diff --git a/src/lte/model/lte-phy.h b/src/lte/model/lte-phy.h
index 9b3f1dc81..184070e99 100644
--- a/src/lte/model/lte-phy.h
+++ b/src/lte/model/lte-phy.h
@@ -159,6 +159,13 @@ public:
   */
   void DoSetBandwidth (uint8_t ulBandwidth, uint8_t dlBandwidth);
 
+  /**  
+   *
+   * \param dlEarfcn the carrier frequency (EARFCN) in downlink
+   * \param ulEarfcn the carrier frequency (EARFCN) in downlink
+   */
+  virtual void DoSetEarfcn (uint16_t dlEarfcn, uint16_t ulEarfcn);
+
   /** 
    * 
    * \param cellId the Cell Identifier
@@ -227,6 +234,9 @@ protected:
   uint8_t m_ulBandwidth;
   uint8_t m_dlBandwidth;
   uint8_t m_rbgSize;
+  
+  uint16_t m_dlEarfcn;
+  uint16_t m_ulEarfcn;
 
   std::vector< Ptr<PacketBurst> > m_packetBurstQueue;
   std::vector< std::list<Ptr<IdealControlMessage> > > m_controlMessagesQueue;
diff --git a/src/lte/model/lte-spectrum-value-helper.cc b/src/lte/model/lte-spectrum-value-helper.cc
index 83fbb9df3..8d834c3bb 100644
--- a/src/lte/model/lte-spectrum-value-helper.cc
+++ b/src/lte/model/lte-spectrum-value-helper.cc
@@ -19,10 +19,10 @@
  *         Nicola Baldo <nbaldo@cttc.es>
  */
 
-
-#include <ns3/log.h>
+#include<map>
 #include <cmath>
 
+#include <ns3/log.h>
 #include "lte-spectrum-value-helper.h"
 
 NS_LOG_COMPONENT_DEFINE ("LteSpectrumValueHelper");
@@ -103,7 +103,7 @@ LteSpectrumValueHelper::GetDownlinkCarrierFrequency (uint16_t nDl)
           (g_eutraChannelNumbers[i].rangeNdl2 >= nDl))
         {
           NS_LOG_LOGIC ("entry " << i << " fDlLow=" << g_eutraChannelNumbers[i].fDlLow);
-          return g_eutraChannelNumbers[i].fDlLow + 0.1 * (nDl - g_eutraChannelNumbers[i].nOffsDl);
+          return 1.0e6 * (g_eutraChannelNumbers[i].fDlLow + 0.1 * (nDl - g_eutraChannelNumbers[i].nOffsDl));
         }
     }
   NS_LOG_ERROR ("invalid EARFCN " << nDl);
@@ -120,134 +120,149 @@ LteSpectrumValueHelper::GetUplinkCarrierFrequency (uint16_t nUl)
           (g_eutraChannelNumbers[i].rangeNul2 >= nUl))
         {
           NS_LOG_LOGIC ("entry " << i << " fUlLow=" << g_eutraChannelNumbers[i].fUlLow);
-          return g_eutraChannelNumbers[i].fUlLow + 0.1 * (nUl - g_eutraChannelNumbers[i].nOffsUl);
+          return 1.0e6 * (g_eutraChannelNumbers[i].fUlLow + 0.1 * (nUl - g_eutraChannelNumbers[i].nOffsUl));
         }
     }
   NS_LOG_ERROR ("invalid EARFCN " << nUl);
   return 0.0;
 }
 
-
-
-Ptr<SpectrumModel> LteDownlinkSpectrumModel;
-Ptr<SpectrumModel> LteUplinkSpectrumModel;
-
-class static_LteDownlinkSpectrumModel_initializer
+double 
+LteSpectrumValueHelper::GetChannelBandwidth (uint8_t transmissionBandwidth)
 {
-public:
-  static_LteDownlinkSpectrumModel_initializer ()
-  {
-
-    /*
-     * Operating  Bands for the UL: 1920 MHz – 1980 MHz
-     * see for details TR.36.101 - Tab 5.5-1
-     *
-     */
-
-    std::vector<double> freqs;
-    /* WILD HACK
-    * banwidth 25
-    */
-    for (int i = 0; i < 25; ++i)
-      {
-
-        double centralFrequencyOfPRB = 1.920 + (i * 0.00018);
-        freqs.push_back (centralFrequencyOfPRB * 1e9);
-      }
-
-    LteDownlinkSpectrumModel = Create<SpectrumModel> (freqs);
-  }
-
-} static_LteDownlinkSpectrumModel_initializer_instance;
+  NS_LOG_FUNCTION ((uint16_t) transmissionBandwidth);
+  switch (transmissionBandwidth)
+    { 
+    case 6:
+      return 1.4e6;
+    case 15:
+      return 3.0e6;
+    case 25:
+      return 5.0e6;
+    case 50:
+      return 10.0e6;
+    case 75:
+      return 15.0e6;
+    case 100:   
+      return 20.0e6;        
+    default:
+      NS_FATAL_ERROR ("invalid bandwidth value " << (uint16_t) transmissionBandwidth);
+    }
+}
 
 
 
-class static_LteUplinkSpectrumModel_initializer
+
+struct LteSpectrumModelId
 {
-public:
-  static_LteUplinkSpectrumModel_initializer ()
-  {
+  LteSpectrumModelId (uint16_t f, uint8_t b);
+  uint16_t earfcn;
+  uint8_t  bandwidth;
+};
 
-    /*
-     * Operating  Bands for the DL: 2110 MHz – 2170 MHz
-     * see for details TR.36.101 - Tab 5.5-1
-     *
-     */
-
-    std::vector<double> freqs;
-    /* WILD HACK
-    * banwidth 25
-    */
-    for (int i = 0; i < 25; ++i)
-      {
-
-        double centralFrequencyOfPRB = 2.110 + (i * 0.00018);
-        freqs.push_back (centralFrequencyOfPRB * 1e9);
-      }
-
-    LteUplinkSpectrumModel = Create<SpectrumModel> (freqs);
-  }
-
-} static_LteUplinkSpectrumModel_initializer_instance;
-
-
-
-
-Ptr<SpectrumValue>
-LteSpectrumValueHelper::CreateDownlinkTxPowerSpectralDensity (double powerTx, std::vector<int> channels)
+LteSpectrumModelId::LteSpectrumModelId (uint16_t f, uint8_t b)
+  : earfcn (f), 
+    bandwidth (b)
 {
-  Ptr<SpectrumValue> txPsd = Create <SpectrumValue> (LteDownlinkSpectrumModel);
+}
+  
+bool
+operator < (const LteSpectrumModelId& a, const LteSpectrumModelId& b)
+{
+  return ( (a.earfcn < b.earfcn) || ( (a.earfcn == b.earfcn) && (a.bandwidth < b.bandwidth) ) );
+}
+ 
+
+static std::map<LteSpectrumModelId, Ptr<SpectrumModel> > g_lteSpectrumModelMap;
+
+
+Ptr<SpectrumModel>
+LteSpectrumValueHelper::GetSpectrumModel (uint16_t earfcn, uint8_t txBandwidthConfiguration)
+{
+  NS_LOG_FUNCTION (earfcn << (uint16_t) txBandwidthConfiguration);
+  Ptr<SpectrumModel> ret;
+  LteSpectrumModelId key (earfcn, txBandwidthConfiguration);
+  std::map<LteSpectrumModelId, Ptr<SpectrumModel> >::iterator it = g_lteSpectrumModelMap.find (key);
+  if (it != g_lteSpectrumModelMap.end ())
+    {
+      ret = it->second;
+    }
+  else
+    {
+      double fc = GetCarrierFrequency (earfcn);
+      NS_ASSERT_MSG (fc != 0, "invalid EARFCN=" << earfcn);
+
+      double f = fc - (txBandwidthConfiguration * 180e3 / 2.0);
+      Bands rbs;
+      for (uint8_t numrb = 0; numrb < txBandwidthConfiguration; ++numrb)
+        {
+          BandInfo rb; 
+          rb.fl = f;
+          f += 90e3;
+          rb.fc = f;
+          f += 90e3;
+          rb.fh = f;          
+          rbs.push_back (rb);
+        }            
+      ret = Create<SpectrumModel> (rbs);
+      g_lteSpectrumModelMap.insert (std::pair<LteSpectrumModelId, Ptr<SpectrumModel> > (key, ret));
+    }
+  NS_LOG_LOGIC ("returning SpectrumModel::GetUid () == " << ret->GetUid ());
+  return ret;
+}
+
+// just needed to log a std::vector<int> properly...
+std::ostream&
+operator << (std::ostream& os, const std::vector<int>& v)
+{
+  std::vector<int>::const_iterator it = v.begin ();
+  while (it != v.end ())
+    {
+      os << *it << " " ;
+      ++it;
+    }
+  os << std::endl;
+  return os;
+}
+
+
+Ptr<SpectrumValue> 
+LteSpectrumValueHelper::CreateTxPowerSpectralDensity (uint16_t earfcn, uint8_t txBandwidthConfiguration, double powerTx, std::vector <int> activeRbs)
+{
+  NS_LOG_FUNCTION (earfcn << (uint16_t) txBandwidthConfiguration << powerTx << activeRbs);
+  
+  Ptr<SpectrumModel> model = GetSpectrumModel (earfcn, txBandwidthConfiguration);  
+  Ptr<SpectrumValue> txPsd = Create <SpectrumValue> (model);
 
   // powerTx is expressed in dBm. We must convert it into natural unit.
-  powerTx = pow (10., (powerTx - 30) / 10);
+  double powerTxW = pow (10., (powerTx - 30) / 10);
 
-  double txPowerDensity = (powerTx / channels.size ()) / 180000;
+  double txPowerDensity = (powerTxW / GetChannelBandwidth (txBandwidthConfiguration));
 
-  for (std::vector <int>::iterator it = channels.begin (); it != channels.end (); it++)
+  for (std::vector <int>::iterator it = activeRbs.begin (); it != activeRbs.end (); it++)
     {
-      int idSubChannel = (*it);
-      (*txPsd)[idSubChannel] = txPowerDensity;
+      int rbId = (*it);
+      (*txPsd)[rbId] = txPowerDensity;
     }
 
+  NS_LOG_LOGIC (*txPsd);
+
   return txPsd;
 }
 
 
 Ptr<SpectrumValue>
-LteSpectrumValueHelper::CreateUplinkTxPowerSpectralDensity (double powerTx, std::vector<int> channels)
+LteSpectrumValueHelper::CreateNoisePowerSpectralDensity (uint16_t earfcn, uint8_t txBandwidthConfiguration, double noiseFigure)
 {
-  Ptr<SpectrumValue> txPsd = Create <SpectrumValue> (LteUplinkSpectrumModel);
-
-  // powerTx is expressed in dBm. We must convert it into natural unit.
-  powerTx = pow (10., (powerTx - 30) / 10);
-
-  double txPowerDensity = (powerTx / channels.size ()) / 180000;
-
-  for (std::vector <int>::iterator it = channels.begin (); it != channels.end (); it++)
-    {
-      int idSubChannel = (*it);
-      (*txPsd)[idSubChannel] = txPowerDensity;
-    }
-
-  return txPsd;
-}
-
-
-Ptr<SpectrumValue>
-LteSpectrumValueHelper::CreateDownlinkNoisePowerSpectralDensity (double noiseFigure)
-{
-  return  CreateNoisePowerSpectralDensity (noiseFigure, LteDownlinkSpectrumModel);
-}
-
-Ptr<SpectrumValue>
-LteSpectrumValueHelper::CreateUplinkNoisePowerSpectralDensity (double noiseFigure)
-{
-  return  CreateNoisePowerSpectralDensity (noiseFigure, LteUplinkSpectrumModel);
+  NS_LOG_FUNCTION (earfcn << (uint16_t) txBandwidthConfiguration << noiseFigure);
+  Ptr<SpectrumModel> model = GetSpectrumModel (earfcn, txBandwidthConfiguration);
+  return  CreateNoisePowerSpectralDensity (noiseFigure, model);
 }
 
 Ptr<SpectrumValue>
 LteSpectrumValueHelper::CreateNoisePowerSpectralDensity (double noiseFigureDb, Ptr<SpectrumModel> spectrumModel)
 {
+  NS_LOG_FUNCTION (noiseFigureDb << spectrumModel);
   double noiseFigureLinear = pow (10.0, noiseFigureDb / 10.0);
   static const double BOLTZMANN = 1.3803e-23;
   static const double ROOM_TEMPERATURE = 290.0;
diff --git a/src/lte/model/lte-spectrum-value-helper.h b/src/lte/model/lte-spectrum-value-helper.h
index 9083dc923..70ce046a9 100644
--- a/src/lte/model/lte-spectrum-value-helper.h
+++ b/src/lte/model/lte-spectrum-value-helper.h
@@ -43,7 +43,7 @@ public:
    *
    * \param earfcn the EARFCN
    * 
-   * \return the carrier frequency in MHz
+   * \return the carrier frequency in Hz
    */
   static double GetCarrierFrequency (uint16_t earfcn);
 
@@ -54,7 +54,7 @@ public:
    *
    * \param earfcn the EARFCN
    * 
-   * \return the dowlink carrier frequency in MHz
+   * \return the dowlink carrier frequency in Hz
    */
   static double GetDownlinkCarrierFrequency (uint16_t earfcn);
 
@@ -65,44 +65,63 @@ public:
    *
    * \param earfcn the EARFCN
    * 
-   * \return the uplink carrier frequency in MHz
+   * \return the uplink carrier frequency in Hz
    */
   static double GetUplinkCarrierFrequency (uint16_t earfcn);  
 
-  /**
-   * \brief create spectrum value
-   * \param powerTx the power transmission in dBm
-   * \param channels the list of sub channels where the signal will be sent
-   * \return a Ptr to a newly created SpectrumValue instance
+  /** 
+   * 
+   * 
+   * \param txBandwidthConf the tranmission bandwidth
+   * configuration in number of resource blocks
+   * 
+   * \return the nominal channel bandwidth in Hz as per 3GPP TS 36.101
    */
-  static Ptr<SpectrumValue> CreateDownlinkTxPowerSpectralDensity (double powerTx, std::vector <int> channels);
+  static double GetChannelBandwidth (uint8_t txBandwidthConf);
+
+   /** 
+    * 
+    * \param earfcn the carrier frequency (EARFCN) at which reception
+    * is made
+    * \param bandwidth the Transmission Bandwidth Configuration in
+    * number of resource blocks
+    * 
+    * \return the static SpectrumModel instance corresponding to the
+    * given carrier frequency and transmission bandwidth
+    * configuration. If such SpectrumModel does not exist, it is
+    * created.  
+    */
+  static Ptr<SpectrumModel> GetSpectrumModel (uint16_t earfcn, uint8_t bandwdith);
+
 
   /**
-   * \brief create spectrum value
-   * \param powerTx the power transmission in dBm
-   * \param channels the list of sub channels where the signal will be sent
+   * create a spectrum value representing the power spectral
+   * density of a signal to be transmitted. See 3GPP TS 36.101 for 
+   * a definition of most of the parameters described here.
+   *
+   * \param earfcn the carrier frequency (EARFCN) of the transmission
+   * \param bandwidth the Transmission Bandwidth Configuration in
+   * number of resource blocks
+   * \param txPower the total power in dBm over the whole bandwidth
+   * \param ActiveRbs the list of Active Resource Blocks (PRBs) 
+   *
    * \return a Ptr to a newly created SpectrumValue instance
    */
-  static Ptr<SpectrumValue> CreateUplinkTxPowerSpectralDensity (double powerTx, std::vector <int> channels);
+  static Ptr<SpectrumValue> CreateTxPowerSpectralDensity (uint16_t earfcn, uint8_t bandwdith, double powerTx, std::vector <int> activeRbs);
 
 
   /**
    * create a SpectrumValue that models the power spectral density of AWGN
    * 
+   * \param earfcn the carrier frequency (EARFCN) at which reception
+   * is made
+   * \param bandwidth the Transmission Bandwidth Configuration in
+   * number of resource blocks
    * \param noiseFigure the noise figure in dB w.r.t. a reference temperature of 290K
    * 
    * \return a Ptr to a newly created SpectrumValue instance
    */
-  static Ptr<SpectrumValue> CreateDownlinkNoisePowerSpectralDensity (double noiseFigure);
-
-  /**
-   *  create a SpectrumValue that models the power spectral density of AWGN
-   * 
-   * \param noiseFigure the noise figure in dB w.r.t. a reference temperature of 290K
-   * 
-   * \return a Ptr to a newly created SpectrumValue instance
-   */
-  static Ptr<SpectrumValue> CreateUplinkNoisePowerSpectralDensity (double noiseFigure);
+  static Ptr<SpectrumValue> CreateNoisePowerSpectralDensity (uint16_t earfcn, uint8_t bandwdith, double noiseFigure);
 
   /** 
    *  create a SpectrumValue that models the power spectral density of AWGN
diff --git a/src/lte/model/lte-ue-net-device.cc b/src/lte/model/lte-ue-net-device.cc
index aceaf3c0c..b7fda8daf 100644
--- a/src/lte/model/lte-ue-net-device.cc
+++ b/src/lte/model/lte-ue-net-device.cc
@@ -144,7 +144,7 @@ LteUeNetDevice::SetTargetEnb (Ptr<LteEnbNetDevice> enb)
   NS_LOG_FUNCTION (this << enb);
   m_targetEnb = enb;
 
-  // WILD HACK - should go through RRC and then through PHY SAP
+  // should go through RRC and then through PHY SAP
   m_phy->DoSetCellId (enb->GetCellId ());
 }
 
@@ -168,6 +168,9 @@ LteUeNetDevice::DoStart (void)
 {
   UpdateConfig ();
   m_imsi = ++m_imsiCounter;
+  m_phy->Start ();
+  m_mac->Start ();
+  m_rrc->Start ();
 }
 
 
diff --git a/src/lte/model/lte-ue-phy.cc b/src/lte/model/lte-ue-phy.cc
index a98736cf3..40708d7eb 100644
--- a/src/lte/model/lte-ue-phy.cc
+++ b/src/lte/model/lte-ue-phy.cc
@@ -153,6 +153,14 @@ LteUePhy::GetTypeId (void)
   return tid;
 }
 
+void
+LteUePhy::DoStart ()
+{
+  NS_LOG_FUNCTION (this);
+  Ptr<SpectrumValue> noisePsd = LteSpectrumValueHelper::CreateNoisePowerSpectralDensity (m_dlEarfcn, m_dlBandwidth, m_noiseFigure);
+  m_downlinkSpectrumPhy->SetNoisePowerSpectralDensity (noisePsd);
+  LtePhy::DoStart ();
+}
 
 void
 LteUePhy::SetLteUePhySapUser (LteUePhySapUser* s)
@@ -173,8 +181,6 @@ LteUePhy::SetNoiseFigure (double nf)
 {
   NS_LOG_FUNCTION (this << nf);
   m_noiseFigure = nf;
-  Ptr<SpectrumValue> noisePsd = LteSpectrumValueHelper::CreateDownlinkNoisePowerSpectralDensity (m_noiseFigure);
-  m_downlinkSpectrumPhy->SetNoisePowerSpectralDensity (noisePsd);
 }
 
 double
@@ -267,7 +273,7 @@ LteUePhy::CreateTxPowerSpectralDensity ()
 {
   NS_LOG_FUNCTION (this);
   LteSpectrumValueHelper psdHelper;
-  Ptr<SpectrumValue> psd = psdHelper.CreateUplinkTxPowerSpectralDensity (GetTxPower (), GetSubChannelsForTransmission ());
+  Ptr<SpectrumValue> psd = psdHelper.CreateTxPowerSpectralDensity (m_ulEarfcn, m_ulBandwidth, m_txPower, GetSubChannelsForTransmission ());
 
   return psd;
 }
diff --git a/src/lte/model/lte-ue-phy.h b/src/lte/model/lte-ue-phy.h
index 376ca45d5..574ed083e 100644
--- a/src/lte/model/lte-ue-phy.h
+++ b/src/lte/model/lte-ue-phy.h
@@ -63,9 +63,10 @@ public:
   
   virtual ~LteUePhy ();
 
-  virtual void DoDispose ();
+  // inherited from Object
   static TypeId GetTypeId (void);
-
+  virtual void DoStart (void);
+  virtual void DoDispose (void);
 
   /**
    * \brief Get the PHY SAP provider
diff --git a/src/lte/test/lte-test-earfcn.cc b/src/lte/test/lte-test-earfcn.cc
index 755afdfc1..857d29abe 100644
--- a/src/lte/test/lte-test-earfcn.cc
+++ b/src/lte/test/lte-test-earfcn.cc
@@ -122,32 +122,32 @@ public:
 static LteEarfcnTestSuite g_lteEarfcnTestSuite;
 
 LteEarfcnTestSuite::LteEarfcnTestSuite ()
-  : TestSuite ("lte-earfcn", SYSTEM)
+  : TestSuite ("lte-earfcn", UNIT)
 {
   NS_LOG_FUNCTION (this);
 
-  AddTestCase (new LteEarfcnDlTestCase ("DL EARFCN=500", 500, 2110+50));
-  AddTestCase (new LteEarfcnDlTestCase ("DL EARFCN=1000", 1000, 1930+(100-60)));
-  AddTestCase (new LteEarfcnDlTestCase ("DL EARFCN=1301", 1301, 1805+(130.1-120)));
+  AddTestCase (new LteEarfcnDlTestCase ("DL EARFCN=500", 500, 2160e6));
+  AddTestCase (new LteEarfcnDlTestCase ("DL EARFCN=1000", 1000, 1970e6));
+  AddTestCase (new LteEarfcnDlTestCase ("DL EARFCN=1301", 1301, 1815.1e6));
   AddTestCase (new LteEarfcnDlTestCase ("DL EARFCN=7000", 7000, 0.0));
   AddTestCase (new LteEarfcnDlTestCase ("DL EARFCN=20000", 20000, 0.0));
   AddTestCase (new LteEarfcnDlTestCase ("DL EARFCN=50000", 50000, 0.0));
 
-  AddTestCase (new LteEarfcnUlTestCase ("UL EARFCN=18100", 18100, 1920 + 1810 - 1800));
-  AddTestCase (new LteEarfcnUlTestCase ("UL EARFCN=19000", 19000, 1850 + 1900 - 1860));
-  AddTestCase (new LteEarfcnUlTestCase ("UL EARFCN=19400", 19400, 1710 + 1940 - 1920));
+  AddTestCase (new LteEarfcnUlTestCase ("UL EARFCN=18100", 18100, 1930e6));
+  AddTestCase (new LteEarfcnUlTestCase ("UL EARFCN=19000", 19000, 1890e6));
+  AddTestCase (new LteEarfcnUlTestCase ("UL EARFCN=19400", 19400, 1730e6));
   AddTestCase (new LteEarfcnUlTestCase ("UL EARFCN=10", 10, 0.0));
   AddTestCase (new LteEarfcnUlTestCase ("UL EARFCN=1000", 1000, 0.0));
   AddTestCase (new LteEarfcnUlTestCase ("UL EARFCN=50000", 50000, 0.0));
 
-  AddTestCase (new LteEarfcnTestCase ("EARFCN=500", 500, 2110+50));
-  AddTestCase (new LteEarfcnTestCase ("EARFCN=1000", 1000, 1930+(100-60)));
-  AddTestCase (new LteEarfcnTestCase ("EARFCN=1301", 1301, 1805+(130.1-120)));
+  AddTestCase (new LteEarfcnTestCase ("EARFCN=500", 500, 2160e6));
+  AddTestCase (new LteEarfcnTestCase ("EARFCN=1000", 1000, 1970e6));
+  AddTestCase (new LteEarfcnTestCase ("EARFCN=1301", 1301, 1815.1e6));
   AddTestCase (new LteEarfcnTestCase ("EARFCN=8000", 8000, 0.0));
   AddTestCase (new LteEarfcnTestCase ("EARFCN=50000", 50000, 0.0));
-  AddTestCase (new LteEarfcnTestCase ("EARFCN=18100", 18100, 1920 + 1810 - 1800));
-  AddTestCase (new LteEarfcnTestCase ("EARFCN=19000", 19000, 1850 + 1900 - 1860));
-  AddTestCase (new LteEarfcnTestCase ("EARFCN=19400", 19400, 1710 + 1940 - 1920));
+  AddTestCase (new LteEarfcnTestCase ("EARFCN=18100", 18100, 1930e6));
+  AddTestCase (new LteEarfcnTestCase ("EARFCN=19000", 19000, 1890e6));
+  AddTestCase (new LteEarfcnTestCase ("EARFCN=19400", 19400, 1730e6));
   AddTestCase (new LteEarfcnTestCase ("EARFCN=50000", 50000, 0.0));
 }
 
diff --git a/src/lte/wscript b/src/lte/wscript
index af8bc8d98..cae9dada4 100644
--- a/src/lte/wscript
+++ b/src/lte/wscript
@@ -57,6 +57,7 @@ def build(bld):
         'test/lte-test-rr-ff-mac-scheduler.cc',
         'test/lte-test-pf-ff-mac-scheduler.cc',
         'test/lte-test-earfcn.cc',
+        'test/lte-test-spectrum-value-helper.cc',
         ]
     
     headers = bld.new_task_gen('ns3header')