diff --git a/src/lte/model/lte-amc.cc b/src/lte/model/lte-amc.cc
index ee122bec3..ae7f32230 100644
--- a/src/lte/model/lte-amc.cc
+++ b/src/lte/model/lte-amc.cc
@@ -297,7 +297,7 @@ LteAmc::GetDlTbSizeFromMcs (int mcs, int nprb)
   NS_LOG_FUNCTION (mcs);
 
   NS_ASSERT_MSG (mcs < 29, "MCS=" << mcs);
-  NS_ASSERT_MSG (nprb < 111, "NPRB=" << nprb);
+  NS_ASSERT_MSG (nprb > 0 && nprb < 111, "NPRB=" << nprb);
 
   int itbs = McsToItbsDl[mcs];
   return (TransportBlockSizeTable[nprb - 1][itbs]);
@@ -309,7 +309,7 @@ LteAmc::GetUlTbSizeFromMcs (int mcs, int nprb)
   NS_LOG_FUNCTION (mcs);
 
   NS_ASSERT_MSG (mcs < 29, "MCS=" << mcs);
-  NS_ASSERT_MSG (nprb < 111, "NPRB=" << nprb);
+  NS_ASSERT_MSG (nprb > 0 && nprb < 111, "NPRB=" << nprb);
 
   int itbs = McsToItbsUl[mcs];
   return (TransportBlockSizeTable[nprb - 1][itbs]);
diff --git a/src/lte/model/tdmt-ff-mac-scheduler.cc b/src/lte/model/tdmt-ff-mac-scheduler.cc
index d06460693..719193d1a 100644
--- a/src/lte/model/tdmt-ff-mac-scheduler.cc
+++ b/src/lte/model/tdmt-ff-mac-scheduler.cc
@@ -942,8 +942,10 @@ TdMtFfMacScheduler::DoSchedDlTriggerReq (const struct FfMacSchedSapProvider::Sch
             } // end for RBG free
 
         } // end for RBGs
-
-      allocationMap.insert (std::pair <uint16_t, std::vector <uint16_t> > ((*itMax), tempMap));
+      if (tempMap.size() > 0)
+        {
+          allocationMap.insert (std::pair <uint16_t, std::vector <uint16_t> > ((*itMax), tempMap));
+        }
     }
 
   // generate the transmission opportunities by grouping the RBGs of the same RNTI and
diff --git a/src/lte/model/tdtbfq-ff-mac-scheduler.cc b/src/lte/model/tdtbfq-ff-mac-scheduler.cc
index f46f407d2..e63833958 100644
--- a/src/lte/model/tdtbfq-ff-mac-scheduler.cc
+++ b/src/lte/model/tdtbfq-ff-mac-scheduler.cc
@@ -1079,7 +1079,10 @@ TdTbfqFfMacScheduler::DoSchedDlTriggerReq (const struct FfMacSchedSapProvider::S
           tempMap.push_back (i);
           rbgMap.at (i) = true;
         }
-      allocationMap.insert (std::pair <uint16_t, std::vector <uint16_t> > ((*itMax).first, tempMap));
+      if (tempMap.size() > 0)
+        {
+          allocationMap.insert (std::pair <uint16_t, std::vector <uint16_t> > ((*itMax).first, tempMap));
+        }
     }