diff --git a/model/isl-mock-channel.cc b/model/isl-mock-channel.cc
index 1bc86b1..a7e438c 100644
--- a/model/isl-mock-channel.cc
+++ b/model/isl-mock-channel.cc
@@ -67,14 +67,13 @@ IslMockChannel::TransmitStart (
 
   if (dst == nullptr)
   {
-    if (src->IsBroadcast () || src->IsMulticast ())
+    if (Mac48Address::ConvertFrom (destAddr).IsBroadcast () || Mac48Address::ConvertFrom (destAddr).IsBroadcast ())
       // try to deliver to every node in LOS
       {
         for (size_t i = 0; i < GetNDevices (); i ++)
           {
             if (i == srcId) continue;
             dst = DynamicCast<MockNetDevice> (GetDevice (i));
-            // TODO check LOS using mobility model
             Deliver (p, src, dst, txTime);
           }
         return true;
diff --git a/model/isl-propagation-loss-model.cc b/model/isl-propagation-loss-model.cc
index 2d123ef..9b379a5 100644
--- a/model/isl-propagation-loss-model.cc
+++ b/model/isl-propagation-loss-model.cc
@@ -83,17 +83,13 @@ IslPropagationLossModel::DoCalcRxPower (double txPowerDbm,
                                         Ptr<MobilityModel> a,
                                         Ptr<MobilityModel> b) const
 {
-
-  // TODO perform line-earth intersection (ray tracing or based on earth
-  // curvature + distance)
-
   // primitivec cut-of at 1000 km
   if (!GetLos (a, b))
     {
-      return 0;
+      return 0.0;
     }
 
-  double rxc = 0;//-m_variable->GetValue ();
+  double rxc = 0.0;//-m_variable->GetValue ();
   NS_LOG_DEBUG ("attenuation coefficient="<<rxc<<"Db");
   return txPowerDbm + rxc;
 }
diff --git a/model/leo-mock-channel.cc b/model/leo-mock-channel.cc
index eeebb0d..46ec5bb 100644
--- a/model/leo-mock-channel.cc
+++ b/model/leo-mock-channel.cc
@@ -73,7 +73,6 @@ LeoMockChannel::TransmitStart (Ptr<const Packet> p,
       return false;
     }
 
-  // TODO deliver only to devices in the same beam
   for (DeviceIndex::iterator it = dests->begin (); it != dests->end(); it ++)
     {
       Deliver (p, srcDev, it->second, txTime);
diff --git a/model/leo-propagation-loss-model.cc b/model/leo-propagation-loss-model.cc
index 40cf948..613e2e1 100644
--- a/model/leo-propagation-loss-model.cc
+++ b/model/leo-propagation-loss-model.cc
@@ -61,13 +61,12 @@ LeoPropagationLossModel::DoCalcRxPower (double txPowerDbm,
                                         Ptr<MobilityModel> a,
                                         Ptr<MobilityModel> b) const
 {
-  // TODO create attributes for max distance and angle
   if (a->GetDistanceFrom (b) > m_cutoffDistance && GetAngle (a, b) > m_cutoffAngle)
     {
-      return 0;
+      return 0.0;
     }
 
-  double rxc = 0;//-m_variable->GetValue ();
+  double rxc = 0.0;//-m_variable->GetValue ();
   //NS_LOG_DEBUG ("attenuation coefficient="<<rxc<<"Db");
   return txPowerDbm + rxc;
 }
diff --git a/model/mock-channel.cc b/model/mock-channel.cc
index 4dde7e9..bba30a2 100644
--- a/model/mock-channel.cc
+++ b/model/mock-channel.cc
@@ -161,6 +161,13 @@ MockChannel::Deliver (
 {
   NS_LOG_FUNCTION (this << p << src->GetAddress () << dst->GetAddress () << txTime);
 
+  double rxPower = GetPropagationLoss ()->CalcRxPower (1.0, src, dst);
+
+  if (rxPower == 0.0)
+    {
+      return false;
+    }
+
   Time delay = GetDelay (src, dst, txTime);
 
   Simulator::ScheduleWithContext (dst->GetNode ()->GetId (),
diff --git a/model/mock-net-device.cc b/model/mock-net-device.cc
index fb9ea5b..ea70150 100644
--- a/model/mock-net-device.cc
+++ b/model/mock-net-device.cc
@@ -578,15 +578,11 @@ MockNetDevice::AddLinkChangeCallback (Callback<void> callback)
   m_linkChangeCallbacks.ConnectWithoutContext (callback);
 }
 
-//
-// This is a point-to-point device, so every transmission is a broadcast to
-// all of the devices on the network.
-//
 bool
 MockNetDevice::IsBroadcast (void) const
 {
   NS_LOG_FUNCTION (this);
-  return true;
+  return false;
 }
 
 //
@@ -605,7 +601,7 @@ bool
 MockNetDevice::IsMulticast (void) const
 {
   NS_LOG_FUNCTION (this);
-  return true;
+  return false;
 }
 
 Address