diff --git a/examples/leo-delay-tracing-example.cc b/examples/leo-delay-tracing-example.cc
index 28b0657..733c48a 100644
--- a/examples/leo-delay-tracing-example.cc
+++ b/examples/leo-delay-tracing-example.cc
@@ -99,12 +99,13 @@ int main (int argc, char *argv[])
     }
   else
     {
-      // Install internet stack on nodes
       AodvHelper aodv;
-      aodv.Set ("EnableHello", BooleanValue (false));
+      //aodv.Set ("EnableHello", BooleanValue (false));
 
       stack.SetRoutingHelper (aodv);
     }
+
+  // Install internet stack on nodes
   stack.Install (satellites);
   stack.Install (stations);
 
diff --git a/model/leo-propagation-loss-model.cc b/model/leo-propagation-loss-model.cc
index 23a49bf..c01a0b5 100644
--- a/model/leo-propagation-loss-model.cc
+++ b/model/leo-propagation-loss-model.cc
@@ -21,12 +21,6 @@ LeoPropagationLossModel::GetTypeId (void)
     .SetParent<PropagationLossModel> ()
     .SetGroupName ("Leo")
     .AddConstructor<LeoPropagationLossModel> ()
-    .AddAttribute ("MaxDistance",
-                   "Cut-off distance for signal propagation",
-                   DoubleValue (2500.0),
-                   MakeDoubleAccessor (&LeoPropagationLossModel::SetCutoffDistance,
-				       &LeoPropagationLossModel::GetCutoffDistance),
-                   MakeDoubleChecker<double> ())
     .AddAttribute ("ElevationAngle",
                    "Cut-off angle for signal propagation",
                    DoubleValue (40.0),
@@ -60,54 +54,45 @@ LeoPropagationLossModel::~LeoPropagationLossModel ()
 {
 }
 
-double
-LeoPropagationLossModel::GetAngle (Ptr<MobilityModel> a, Ptr<MobilityModel> b)
-{
-  Vector3D x = a->GetPosition ();
-  Vector3D y = b->GetPosition ();
-
-  Vector3D pa, pb;
-  if (x.GetLength () < y.GetLength ())
-    {
-      pa = x - y;
-      pb = y;
-      NS_LOG_DEBUG ("LEO ground -> space");
-    }
-  else
-    {
-      pa = y - x;
-      pb = x;
-      NS_LOG_DEBUG ("LEO space -> ground");
-    }
-
-  double prod = abs ((pa.x*-pb.x) + (pa.y*-pb.y) + (pa.z*-pb.z));
-  double norm = pa.GetLength () * pb.GetLength ();
-
-  return acos (prod / norm);
-}
-
 void
 LeoPropagationLossModel::SetElevationAngle (double angle)
 {
-  m_elevationAngle = (90 - angle) * (M_PI/180.0);
+  m_elevationAngle = angle * (M_PI/180.0);
+}
+
+double
+LeoPropagationLossModel::GetCutoffDistance (const Ptr<MobilityModel> sat) const
+{
+  double angle = m_elevationAngle;
+  double hs = sat->GetPosition ().GetLength ();
+
+  double a = 1 + tan (angle) * tan (angle);
+  double b = 2.0 * tan (angle) * hs;
+  double c = hs*hs - LEO_PROP_EARTH_RAD*LEO_PROP_EARTH_RAD;
+
+  double disc = b*b + 4*a*c;
+
+  NS_LOG_DEBUG ("angle="<<angle<<" hs="<<hs<<" a="<<a<<" b="<<b<<" c="<<c<<" disc="<<disc);
+
+  if (disc < 0)
+    {
+      // point not on earth surface
+      return - 1.0;
+    }
+
+  double t1 = (-b - sqrt (disc)) / (2.0 * a);
+  double t2 = (-b + sqrt (disc)) / (2.0 * a);
+
+  double num1 = Vector2D (t1, - tan (angle) * t1).GetLength ();
+  double num2 = Vector2D (t2, - tan (angle) * t2).GetLength ();
+
+  return fmin (num1, num2);
 }
 
 double
 LeoPropagationLossModel::GetElevationAngle () const
 {
-  return 90 - (m_elevationAngle * (180.0/M_PI));
-}
-
-void
-LeoPropagationLossModel::SetCutoffDistance (double d)
-{
-  m_cutoffDistance = d * 1000.0;
-}
-
-double
-LeoPropagationLossModel::GetCutoffDistance () const
-{
-  return m_cutoffDistance / 1000.0;
+  return m_elevationAngle * (180.0/M_PI);
 }
 
 double
@@ -115,27 +100,21 @@ LeoPropagationLossModel::DoCalcRxPower (double txPowerDbm,
                                         Ptr<MobilityModel> a,
                                         Ptr<MobilityModel> b) const
 {
+  Ptr<MobilityModel> sat = a->GetPosition ().GetLength () > b->GetPosition ().GetLength () ? a : b;
   double distance = a->GetDistanceFrom (b);
-
-  if (distance > m_cutoffDistance)
+  double cutOff = GetCutoffDistance (sat);
+  if (distance > cutOff)
     {
-      NS_LOG_DEBUG ("LEO DROP distance: a=" << a->GetPosition () << " b=" << b->GetPosition ()<<" dist=" << distance);
+      NS_LOG_DEBUG ("LEO DROP distance: a=" << a->GetPosition () << " b=" << b->GetPosition ()<<" dist=" << distance<<" cutoff="<<cutOff);
 
       return -1000.0;
     }
 
-  double angle = GetAngle (a, b);
-  if (angle > m_elevationAngle)
-    {
-      NS_LOG_DEBUG ("LEO DROP angle: a=" << a->GetPosition () << " b=" << b->GetPosition () << " dist=" << distance << "angle=" << angle);
-      return -1000.0;
-    }
-
   // txPowerDbm includes tx antenna gain and losses
   // receiver loss and gain added at net device
   // P_{RX} = P_{TX} + G_{TX} - L_{TX} - L_{FS} - L_M + G_{RX} - L_{RX}
   double rxc = txPowerDbm - m_atmosphericLoss - m_freeSpacePathLoss - m_linkMargin;
-  NS_LOG_DEBUG ("LEO TRANSMIT: angle=" << angle <<";distance=" << distance << ";rxc=" << rxc);
+  NS_LOG_DEBUG ("LEO TRANSMIT distance: a=" << a->GetPosition () << " b=" << b->GetPosition ()<<" dist=" << distance <<" cutoff="<<cutOff<< "rxc=" << rxc);
 
   return rxc;
 }
diff --git a/model/leo-propagation-loss-model.h b/model/leo-propagation-loss-model.h
index 52eb96a..7c1478f 100644
--- a/model/leo-propagation-loss-model.h
+++ b/model/leo-propagation-loss-model.h
@@ -6,6 +6,8 @@
 #include <ns3/object.h>
 #include <ns3/propagation-loss-model.h>
 
+#define LEO_PROP_EARTH_RAD 6.37101e6
+
 namespace ns3 {
 
 class LeoPropagationLossModel : public PropagationLossModel
@@ -15,15 +17,8 @@ public:
   LeoPropagationLossModel ();
   virtual ~LeoPropagationLossModel ();
 
-  static double GetAngle (Ptr<MobilityModel> a, Ptr<MobilityModel> b);
-
 private:
 
-  /**
-   * Cutoff distance for signal
-   */
-  double m_cutoffDistance;
-
   /**
    * Maximum elevation angle
    */
@@ -65,8 +60,7 @@ private:
   void SetElevationAngle (double angle);
   double GetElevationAngle () const;
 
-  void SetCutoffDistance (double d);
-  double GetCutoffDistance () const;
+  double GetCutoffDistance (const Ptr<MobilityModel> sat) const;
 };
 
 }
diff --git a/model/mock-channel.cc b/model/mock-channel.cc
index 2e177ca..fec4bac 100644
--- a/model/mock-channel.cc
+++ b/model/mock-channel.cc
@@ -168,7 +168,7 @@ MockChannel::Deliver (
     	{
       	  // check if signal reaches destination
       	  rxPower = pLoss->CalcRxPower (txPower, srcMob, dstMob);
-      	  if (rxPower <= -1000.0)
+      	  if (rxPower < -900.0)
     	    {
       	      NS_LOG_WARN (this << "unable to reach destination " << dst->GetNode ()->GetId () << " from " << src->GetNode ()->GetId ());
       	      return false;
diff --git a/test/leo-propagation-test-suite.cc b/test/leo-propagation-test-suite.cc
index ef19298..7dd9a0d 100644
--- a/test/leo-propagation-test-suite.cc
+++ b/test/leo-propagation-test-suite.cc
@@ -8,102 +8,6 @@
 
 using namespace ns3;
 
-class LeoPropagationAngleTestCase1 : public TestCase
-{
-public:
-  LeoPropagationAngleTestCase1 ();
-  virtual ~LeoPropagationAngleTestCase1 ();
-
-private:
-  virtual void DoRun (void);
-};
-
-LeoPropagationAngleTestCase1::LeoPropagationAngleTestCase1 ()
-  : TestCase ("Test angle computation 90 deg")
-{
-}
-
-LeoPropagationAngleTestCase1::~LeoPropagationAngleTestCase1 ()
-{
-}
-
-void
-LeoPropagationAngleTestCase1::DoRun (void)
-{
-  Ptr<ConstantPositionMobilityModel> a = CreateObject<ConstantPositionMobilityModel> ();
-  a->SetPosition (Vector3D (10, 0, 0));
-  Ptr<ConstantPositionMobilityModel> b = CreateObject<ConstantPositionMobilityModel> ();
-  b->SetPosition (Vector3D (0, 10, 0));
-
-  double angle = LeoPropagationLossModel::GetAngle (a, b);
-
-  NS_TEST_ASSERT_MSG_EQ ((M_PI/4 - 0.1 < angle && angle < M_PI/4 + 0.1), true, "Angle should be 90 deg.");
-}
-
-class LeoPropagationAngleTestCase2 : public TestCase
-{
-public:
-  LeoPropagationAngleTestCase2 ();
-  virtual ~LeoPropagationAngleTestCase2 ();
-
-private:
-  virtual void DoRun (void);
-};
-
-LeoPropagationAngleTestCase2::LeoPropagationAngleTestCase2 ()
-  : TestCase ("Test angle computation 0 deg")
-{
-}
-
-LeoPropagationAngleTestCase2::~LeoPropagationAngleTestCase2 ()
-{
-}
-
-void
-LeoPropagationAngleTestCase2::DoRun (void)
-{
-  Ptr<ConstantPositionMobilityModel> a = CreateObject<ConstantPositionMobilityModel> ();
-  a->SetPosition (Vector3D (10, 0, 0));
-  Ptr<ConstantPositionMobilityModel> b = CreateObject<ConstantPositionMobilityModel> ();
-  b->SetPosition (Vector3D (10, 0, 0));
-
-  double angle = LeoPropagationLossModel::GetAngle (a, b);
-
-  NS_TEST_ASSERT_MSG_EQ (isnan(angle), true, "Angle should be 0 deg.");
-}
-
-class LeoPropagationAngleTestCase3 : public TestCase
-{
-public:
-  LeoPropagationAngleTestCase3 ();
-  virtual ~LeoPropagationAngleTestCase3 ();
-
-private:
-  virtual void DoRun (void);
-};
-
-LeoPropagationAngleTestCase3::LeoPropagationAngleTestCase3 ()
-  : TestCase ("Test angle computation 0 vector")
-{
-}
-
-LeoPropagationAngleTestCase3::~LeoPropagationAngleTestCase3 ()
-{
-}
-
-void
-LeoPropagationAngleTestCase3::DoRun (void)
-{
-  Ptr<ConstantPositionMobilityModel> a = CreateObject<ConstantPositionMobilityModel> ();
-  a->SetPosition (Vector3D (0, 0, 0));
-  Ptr<ConstantPositionMobilityModel> b = CreateObject<ConstantPositionMobilityModel> ();
-  b->SetPosition (Vector3D (0, 0, 0));
-
-  double angle = LeoPropagationLossModel::GetAngle (a, b);
-
-  NS_TEST_ASSERT_MSG_EQ (isnan(angle), true, "Angle should be NaN");
-}
-
 class LeoPropagationRxNoLosTestCase : public TestCase
 {
 public:
@@ -228,9 +132,6 @@ LeoPropagationTestSuite::LeoPropagationTestSuite ()
   : TestSuite ("leo-propagation", UNIT)
 {
   // TestDuration for TestCase can be QUICK, EXTENSIVE or TAKES_FOREVER
-  AddTestCase (new LeoPropagationAngleTestCase1, TestCase::QUICK);
-  AddTestCase (new LeoPropagationAngleTestCase2, TestCase::QUICK);
-  AddTestCase (new LeoPropagationAngleTestCase3, TestCase::QUICK);
   AddTestCase (new LeoPropagationRxNoLosTestCase, TestCase::QUICK);
   AddTestCase (new LeoPropagationRxLosTestCase, TestCase::QUICK);
   AddTestCase (new LeoPropagationBadAngleTestCase, TestCase::QUICK);