diff --git a/src/core/model/nstime.h b/src/core/model/nstime.h
index 5e83b66f7..109d899a5 100644
--- a/src/core/model/nstime.h
+++ b/src/core/model/nstime.h
@@ -698,8 +698,11 @@ private:
   friend Time operator - (const Time & lhs, const Time & rhs);
   friend Time operator * (const Time & lhs, const int64_t & rhs);
   friend Time operator * (const int64_t & lhs, const Time & rhs);
-  friend int64_t operator / (const Time & lhs, const Time & rhs);
+  friend Time operator * (const Time & lhs, const int64x64_t & rhs);
+  friend Time operator * (const int64x64_t & lhs, const Time & rhs);
+  friend int64x64_t operator / (const Time & lhs, const Time & rhs);
   friend Time operator / (const Time & lhs, const int64_t & rhs);
+  friend Time operator / (const Time & lhs, const int64x64_t & rhs);
   friend Time & operator += (Time & lhs, const Time & rhs);
   friend Time & operator -= (Time & lhs, const Time & rhs);
   /** @} */
@@ -746,6 +749,9 @@ static bool NS_UNUSED_GLOBAL (g_TimeStaticInit) = Time::StaticInit ();
 
 /**
  * \ingroup time
+ * @{
+ */
+/**
  * \brief Equality operator for Time.
  * \param [in] lhs The first value
  * \param [in] rhs The second value
@@ -866,6 +872,32 @@ operator * (const int64_t & lhs, const Time & rhs)
   res.m_data *= lhs;
   return res;
 }
+/**
+ * \ingroup time
+ * \brief Multiplication operator for Time.
+ * \param [in] lhs The first value
+ * \param [in] rhs The second value
+ * \returns the product of the two input values.
+ */
+inline Time
+operator * (const Time & lhs, const int64x64_t & rhs)
+{
+  int64x64_t res = lhs.m_data;
+  res *= rhs;
+  return Time (res);
+}
+/**
+ * \ingroup time
+ * \brief Multiplication operator for Time.
+ * \param [in] lhs The first value
+ * \param [in] rhs The second value
+ * \returns the product of the two input values.
+ */
+inline Time
+operator * (const int64x64_t & lhs, const Time & rhs)
+{
+  return rhs * lhs;
+}
 /**
  * \ingroup time
  * \brief Division operator for Time.
@@ -873,11 +905,12 @@ operator * (const int64_t & lhs, const Time & rhs)
  * \param [in] rhs The second value
  * \returns the resultof the first input value divided by the second input value.
  */
-inline int64_t
+inline int64x64_t
 operator / (const Time & lhs, const Time & rhs)
 {
-  int64_t res = lhs.m_data / rhs.m_data;
-  return res;
+  int64x64_t num = lhs.m_data;
+  int64x64_t den = rhs.m_data;
+  return num / den;
 }
 /**
  * \ingroup time
@@ -893,6 +926,20 @@ operator / (const Time & lhs, const int64_t & rhs)
   res.m_data /= rhs;
   return res;
 }
+/**
+ * \ingroup time
+ * \brief Division operator for Time.
+ * \param [in] lhs The first value
+ * \param [in] rhs The second value
+ * \returns the resultof the first input value divided by the second input value.
+ */
+inline Time
+operator / (const Time & lhs, const int64x64_t & rhs)
+{
+  int64x64_t res = lhs.m_data;
+  res /= rhs;
+  return Time (res);
+}
 /**
  * \ingroup time
  * \brief Addition operator for Time.
@@ -917,7 +964,6 @@ inline Time & operator -= (Time & lhs, const Time & rhs)
   lhs.m_data -= rhs.m_data;
   return lhs;
 }
-/**@}*/
   
 inline Time Abs (const Time & time)
 {
@@ -961,6 +1007,8 @@ std::ostream & operator << (std::ostream & os, const Time & time);
  */
 std::istream & operator >> (std::istream & is, Time & time);
 
+/**@}*/  // \ingroup time
+
 /**
  * \ingroup time
  * \defgroup timecivil Standard Time Units.
diff --git a/src/internet/test/tcp-hybla-test.cc b/src/internet/test/tcp-hybla-test.cc
index 996fc742b..76740c5dc 100644
--- a/src/internet/test/tcp-hybla-test.cc
+++ b/src/internet/test/tcp-hybla-test.cc
@@ -111,7 +111,7 @@ TcpHyblaIncrementTest::DoRun ()
 
   NS_TEST_ASSERT_MSG_NE (m_rho, 0.0,
                          "Rho never updated by implementation");
-  NS_TEST_ASSERT_MSG_EQ_TOL (calcRho, m_rho, MilliSeconds (10),
+  NS_TEST_ASSERT_MSG_EQ_TOL (calcRho, m_rho, 0.01,
                          "Different rho values between implementation and test");
 
   cong->IncreaseWindow (m_state, 1);
diff --git a/src/mpi/model/distributed-simulator-impl.cc b/src/mpi/model/distributed-simulator-impl.cc
index bfcab866a..ed842a0e7 100644
--- a/src/mpi/model/distributed-simulator-impl.cc
+++ b/src/mpi/model/distributed-simulator-impl.cc
@@ -284,7 +284,7 @@ DistributedSimulatorImpl::CalculateLookAhead (void)
 void
 DistributedSimulatorImpl::SetMaximumLookAhead (const Time lookAhead)
 {
-  if (lookAhead > 0)
+  if (lookAhead > Time (0))
     {
       NS_LOG_FUNCTION (this << lookAhead);
       m_lookAhead = lookAhead;
diff --git a/src/network/helper/delay-jitter-estimation.cc b/src/network/helper/delay-jitter-estimation.cc
index 21448c210..c65ce2020 100644
--- a/src/network/helper/delay-jitter-estimation.cc
+++ b/src/network/helper/delay-jitter-estimation.cc
@@ -134,7 +134,7 @@ DelayJitterEstimation::RecordRx (Ptr<const Packet> packet)
   tag.GetTxTime ();
 
   Time delta = (Simulator::Now () - m_previousRx) - (tag.GetTxTime () - m_previousRxTx);
-  m_jitter += (Abs (delta) - m_jitter) / 16;
+  m_jitter += (Abs (delta) - m_jitter) / (int64x64_t)16;
   m_previousRx = Simulator::Now ();
   m_previousRxTx = tag.GetTxTime ();
   m_delay = Simulator::Now () - tag.GetTxTime ();
diff --git a/src/wave/model/default-channel-scheduler.cc b/src/wave/model/default-channel-scheduler.cc
index 25bdfc0c3..f44534212 100644
--- a/src/wave/model/default-channel-scheduler.cc
+++ b/src/wave/model/default-channel-scheduler.cc
@@ -259,7 +259,7 @@ DefaultChannelScheduler::AssignExtendedAccess (uint32_t channelNumber, uint32_t
         {
           // if current remain extends cannot fulfill the requirement for extends
           Time remainTime = Simulator::GetDelayLeft (m_extendEvent);
-          uint32_t remainExtends = remainTime / m_coordinator->GetSyncInterval ();
+          uint32_t remainExtends = (remainTime / m_coordinator->GetSyncInterval ()).GetHigh ();
           if (remainExtends > extends)
             {
               return true;
diff --git a/src/wifi/model/channel-access-manager.cc b/src/wifi/model/channel-access-manager.cc
index 46d766679..1c68fb559 100644
--- a/src/wifi/model/channel-access-manager.cc
+++ b/src/wifi/model/channel-access-manager.cc
@@ -486,7 +486,7 @@ ChannelAccessManager::UpdateBackoff (void)
       Time backoffStart = GetBackoffStartFor (state);
       if (backoffStart <= Simulator::Now ())
         {
-          uint32_t nIntSlots = (Simulator::Now () - backoffStart) / m_slot;
+          uint32_t nIntSlots = ((Simulator::Now () - backoffStart) / m_slot).GetHigh ();
           /*
            * EDCA behaves slightly different to DCA. For EDCA we
            * decrement once at the slot boundary at the end of AIFS as
diff --git a/src/wifi/model/mac-low.cc b/src/wifi/model/mac-low.cc
index d00ac9e3b..97a888879 100644
--- a/src/wifi/model/mac-low.cc
+++ b/src/wifi/model/mac-low.cc
@@ -1462,7 +1462,7 @@ MacLow::ForwardDown (Ptr<const Packet> packet, const WifiMacHeader* hdr, WifiTxV
             }
           if (queueSize > 1)
             {
-              NS_ASSERT (remainingAmpduDuration > 0);
+              NS_ASSERT (remainingAmpduDuration > Time (0));
               delay = delay + mpduDuration;
             }
 
diff --git a/src/wifi/model/minstrel-wifi-manager.cc b/src/wifi/model/minstrel-wifi-manager.cc
index 4de961fc5..05b8b20a6 100644
--- a/src/wifi/model/minstrel-wifi-manager.cc
+++ b/src/wifi/model/minstrel-wifi-manager.cc
@@ -965,7 +965,7 @@ MinstrelWifiManager::CalculateTimeUnicastPacket (Time dataTransmissionTime, uint
       tt += dataTransmissionTime + GetMac ()->GetAckTimeout ();
 
       //Add average back off (half the current contention window)
-      tt += NanoSeconds ((cw / 2) * GetMac ()->GetSlot ());
+      tt += (cw / 2.0) * GetMac ()->GetSlot ();
 
       //Update contention window
       cw = std::min (cwMax, (cw + 1) * 2);
diff --git a/src/wimax/model/bs-uplink-scheduler-mbqos.cc b/src/wimax/model/bs-uplink-scheduler-mbqos.cc
index 161af1f83..a91a18005 100644
--- a/src/wimax/model/bs-uplink-scheduler-mbqos.cc
+++ b/src/wimax/model/bs-uplink-scheduler-mbqos.cc
@@ -312,7 +312,7 @@ UplinkSchedulerMBQoS::Schedule (void)
                         (*(ssRecord->GetServiceFlows (ServiceFlow::SF_TYPE_UGS).begin ()))->GetRecord ()->GetLastGrantTime ()
                         + MilliSeconds ((*(ssRecord->GetServiceFlows (ServiceFlow::SF_TYPE_UGS).begin ()))->GetUnsolicitedGrantInterval ());
 
-                      int64_t frame = (timestamp - Simulator::Now ()) / frame_duration;
+                      int64_t frame = ((timestamp - Simulator::Now ()) / frame_duration).GetHigh ();
 
                       if (frame <= 1)
                         {
@@ -663,7 +663,7 @@ UplinkSchedulerMBQoS::CheckDeadline (uint32_t &availableSymbols)
               Time deadline = job->GetDeadline ();
               Time frame_duration = GetBs ()->GetPhy ()->GetFrameDuration ();
 
-              int64_t frame = (deadline - Simulator::Now ()) / frame_duration;
+              int64_t frame = ((deadline - Simulator::Now ()) / frame_duration).GetHigh ();
 
               NS_LOG_DEBUG ("At " << Simulator::Now ().GetSeconds () << " reserved traffic rate: "
                                   << job->GetServiceFlow ()->GetMinReservedTrafficRate ()