diff --git a/src/devices/mesh/dot11s/airtime-metric.cc b/src/devices/mesh/dot11s/airtime-metric.cc
index cf6c27574..b1b6e2863 100644
--- a/src/devices/mesh/dot11s/airtime-metric.cc
+++ b/src/devices/mesh/dot11s/airtime-metric.cc
@@ -31,7 +31,7 @@ AirtimeLinkMetricCalculator::GetTypeId ()
     .SetParent<Object> ()
     .AddConstructor<AirtimeLinkMetricCalculator> ()
     .AddAttribute ( "OverheadNanosec",
-                    "Overhead expressed in nanoseconds:DIFS+ 2* SIFS + 2* PREAMBLE + 2* ACK",
+                    "Overhead expressed in nanoseconds:DIFS+ SIFS + 2 * PREAMBLE + ACK",
                     UintegerValue (108000),
                     MakeUintegerAccessor (&AirtimeLinkMetricCalculator::m_overheadNanosec),
                     MakeUintegerChecker<uint32_t> (1)
@@ -80,9 +80,9 @@ AirtimeLinkMetricCalculator::CalculateMetric (Mac48Address peerAddress, Ptr<Mesh
 
   WifiRemoteStation * station = mac->GetStationManager ()->Lookup (peerAddress);
   NS_ASSERT (station != 0);
-  Ptr<Packet> test_frame = Create<Packet> (m_testLength + m_headerLength + m_meshHeaderLength);
+  Ptr<Packet> test_frame = Create<Packet> (m_testLength + m_meshHeaderLength);
   uint32_t rate =
-      station->GetDataMode (test_frame, m_testLength + m_headerLength + m_meshHeaderLength).GetDataRate ();
+      station->GetDataMode (test_frame, m_testLength + m_meshHeaderLength).GetDataRate ();
   uint32_t payload_nanosec = (uint32_t) (
       (double) ((m_testLength + m_meshHeaderLength) * 8 /*octets -> bits*/) * sec2ns / ((double) rate));
   uint32_t header_nanosec = (uint32_t) ((double) (m_headerLength * 8 /*octets -> bits*/* sec2ns)
diff --git a/src/devices/mesh/dot11s/airtime-metric.h b/src/devices/mesh/dot11s/airtime-metric.h
index 6755ac6b5..0f98cc480 100644
--- a/src/devices/mesh/dot11s/airtime-metric.h
+++ b/src/devices/mesh/dot11s/airtime-metric.h
@@ -45,13 +45,13 @@ public:
   static TypeId GetTypeId ();
   uint32_t CalculateMetric (Mac48Address peerAddress, Ptr<MeshWifiInterfaceMac> mac);
 private:
-  //\brief Overhead expressed in nanoseconds:DIFS+ 2* SIFS + 2*PREAMBLE + 2* ACK
+  /// Overhead expressed in nanoseconds:DIFS + SIFS + 2 * PREAMBLE + ACK
   uint32_t m_overheadNanosec;
-  ///\brief Bt value
+  /// Bt value
   uint32_t m_testLength;
-  ///\brief header length (used in overhead)
+  /// header length (used in overhead)
   uint16_t m_headerLength;
-  ///\brief meshHeader length (6 octets usually)
+  /// meshHeader length (minimum 6 octets)
   uint16_t m_meshHeaderLength;
 };
 } //namespace dot11s
diff --git a/src/devices/mesh/dot11s/hwmp-protocol.cc b/src/devices/mesh/dot11s/hwmp-protocol.cc
index 9b30de4c6..b333e5801 100644
--- a/src/devices/mesh/dot11s/hwmp-protocol.cc
+++ b/src/devices/mesh/dot11s/hwmp-protocol.cc
@@ -33,6 +33,7 @@
 #include "airtime-metric.h"
 #include "ie-dot11s-preq.h"
 #include "ie-dot11s-prep.h"
+#include "ns3/trace-source-accessor.h"
 #include "ie-dot11s-perr.h"
 
 NS_LOG_COMPONENT_DEFINE ("HwmpProtocol");
@@ -157,7 +158,13 @@ HwmpProtocol::GetTypeId ()
                     MakeBooleanAccessor (
                         &HwmpProtocol::m_rfFlag),
                     MakeBooleanChecker ()
-        );
+                    )
+    .AddTraceSource ( "RouteDiscoveryTime",
+                      "The time of route discovery procedure",
+                      MakeTraceSourceAccessor (
+                        &HwmpProtocol::m_routeDiscoveryTimeCallback)
+                      )
+        ;
   return tid;
 }
 
@@ -201,14 +208,14 @@ void
 HwmpProtocol::DoDispose ()
 {
   NS_LOG_FUNCTION_NOARGS ();
-  for (std::map<Mac48Address, EventId>::iterator i = m_preqTimeouts.begin (); i != m_preqTimeouts.end (); i ++)
+  for (std::map<Mac48Address, PreqEvent>::iterator i = m_preqTimeouts.begin (); i != m_preqTimeouts.end (); i ++)
     {
-      i->second.Cancel ();
+      i->second.preqTimeout.Cancel ();
     }
   m_proactivePreqTimer.Cancel();
   m_preqTimeouts.clear ();
   m_lastDataSeqno.clear ();
-  m_lastHwmpSeqno.clear ();
+  m_hwmpSeqnoMetricDatabase.clear ();
   m_interfaces.clear ();
   m_rqueue.clear ();
   m_rtable = 0;
@@ -392,31 +399,24 @@ HwmpProtocol::ReceivePreq (IePreq preq, Mac48Address from, uint32_t interface, M
 {
   preq.IncrementMetric (metric);
   //acceptance cretirea:
-  std::map<Mac48Address, uint32_t>::const_iterator i = m_lastHwmpSeqno.find (preq.GetOriginatorAddress());
-  if (i == m_lastHwmpSeqno.end ())
+  std::map<Mac48Address, std::pair<uint32_t, uint32_t> >::const_iterator i = m_hwmpSeqnoMetricDatabase.find (
+      preq.GetOriginatorAddress ());
+  if (i != m_hwmpSeqnoMetricDatabase.end ())
     {
-      m_lastHwmpSeqno[preq.GetOriginatorAddress ()] = preq.GetOriginatorSeqNumber ();
-      m_lastHwmpMetric[preq.GetOriginatorAddress ()] = preq.GetMetric ();
-    }
-  else
-    {
-      if ((int32_t)(i->second - preq.GetOriginatorSeqNumber ())  > 0)
+      if ((int32_t)(i->second.first - preq.GetOriginatorSeqNumber ())  > 0)
         {
           return;
         }
-      if (i->second == preq.GetOriginatorSeqNumber ())
+      if (i->second.first == preq.GetOriginatorSeqNumber ())
         {
-          //find metric
-          std::map<Mac48Address, uint32_t>::const_iterator j = m_lastHwmpMetric.find (preq.GetOriginatorAddress());
-          NS_ASSERT (j != m_lastHwmpSeqno.end ());
-          if (j->second <= preq.GetMetric ())
+          if (i->second.second <= preq.GetMetric ())
             {
               return;
             }
         }
-      m_lastHwmpSeqno[preq.GetOriginatorAddress ()] = preq.GetOriginatorSeqNumber ();
-      m_lastHwmpMetric[preq.GetOriginatorAddress ()] = preq.GetMetric ();
     }
+  m_hwmpSeqnoMetricDatabase[preq.GetOriginatorAddress ()] = std::make_pair (preq.GetOriginatorSeqNumber (), preq.GetMetric ());
+
   NS_LOG_DEBUG("I am " << GetAddress () << "Accepted preq from address" << from << ", preq:" << preq);
   std::vector<Ptr<DestinationAddressUnit> > destinations = preq.GetDestinationList ();
   //Add reactive path to originator:
@@ -559,25 +559,16 @@ HwmpProtocol::ReceivePrep (IePrep prep, Mac48Address from, uint32_t interface, M
 {
   prep.IncrementMetric (metric);
   //acceptance cretirea:
-  std::map<Mac48Address, uint32_t>::const_iterator i = m_lastHwmpSeqno.find (prep.GetOriginatorAddress ());
-  if (i == m_lastHwmpSeqno.end ())
+  std::map<Mac48Address, std::pair<uint32_t, uint32_t> >::const_iterator i = m_hwmpSeqnoMetricDatabase.find (
+      prep.GetOriginatorAddress ());
+  if ((i != m_hwmpSeqnoMetricDatabase.end ()) && ((int32_t)(i->second.first - prep.GetOriginatorSeqNumber ()) > 0))
     {
-      m_lastHwmpSeqno[prep.GetOriginatorAddress ()] = prep.GetOriginatorSeqNumber ();
+      return;
     }
-  else
-  {
-    if ((int32_t)(i->second - prep.GetOriginatorSeqNumber ()) > 0)
-      {
-        return;
-      }
-    else
-      {
-        m_lastHwmpSeqno[prep.GetOriginatorAddress ()] = prep.GetOriginatorSeqNumber ();
-      }
-  }
+  m_hwmpSeqnoMetricDatabase[prep.GetOriginatorAddress ()] = std::make_pair (prep.GetOriginatorSeqNumber (), prep.GetMetric ());
   //update routing info
   //Now add a path to destination and add precursor to source
-  NS_LOG_DEBUG("I am " << GetAddress () << ", received prep from " << prep.GetOriginatorAddress () << ", receiver was:" << from);
+  NS_LOG_DEBUG ("I am " << GetAddress () << ", received prep from " << prep.GetOriginatorAddress () << ", receiver was:" << from);
   HwmpRtable::LookupResult result = m_rtable->LookupReactive (prep.GetDestinationAddress ());
   //Add a reactive path only if it is better than existing:
   if (
@@ -904,6 +895,12 @@ HwmpProtocol::DequeueFirstPacket ()
 void
 HwmpProtocol::ReactivePathResolved (Mac48Address dst)
 {
+  std::map<Mac48Address, PreqEvent>::iterator i = m_preqTimeouts.find (dst);
+  if (i !=  m_preqTimeouts.end ())
+    {
+      m_routeDiscoveryTimeCallback (Simulator::Now () - i->second.whenScheduled);
+    }
+
   HwmpRtable::LookupResult result = m_rtable->LookupReactive (dst);
   NS_ASSERT(result.retransmitter != Mac48Address::GetBroadcast ());
   //Send all packets stored for this destination
@@ -950,12 +947,13 @@ HwmpProtocol::ProactivePathResolved ()
 bool
 HwmpProtocol::ShouldSendPreq (Mac48Address dst)
 {
-  std::map<Mac48Address, EventId>::const_iterator i = m_preqTimeouts.find (dst);
+  std::map<Mac48Address, PreqEvent>::const_iterator i = m_preqTimeouts.find (dst);
   if (i == m_preqTimeouts.end ())
     {
-      m_preqTimeouts[dst] = Simulator::Schedule (
+      m_preqTimeouts[dst].preqTimeout = Simulator::Schedule (
           m_dot11MeshHWMPnetDiameterTraversalTime * Scalar (2),
           &HwmpProtocol::RetryPathDiscovery, this, dst, 1);
+      m_preqTimeouts[dst].whenScheduled = Simulator::Now ();
       return true;
     }
   return false;
@@ -970,8 +968,8 @@ HwmpProtocol::RetryPathDiscovery (Mac48Address dst, uint8_t numOfRetry)
     }
   if (result.retransmitter != Mac48Address::GetBroadcast ())
     {
-      std::map<Mac48Address, EventId>::iterator i = m_preqTimeouts.find (dst);
-      NS_ASSERT (i !=  m_preqTimeouts.end ());
+      std::map<Mac48Address, PreqEvent>::iterator i = m_preqTimeouts.find (dst);
+      NS_ASSERT (i != m_preqTimeouts.end ());
       m_preqTimeouts.erase (i);
       return;
     }
@@ -986,8 +984,9 @@ HwmpProtocol::RetryPathDiscovery (Mac48Address dst, uint8_t numOfRetry)
           packet.reply (false, packet.pkt, packet.src, packet.dst, packet.protocol, HwmpRtable::MAX_METRIC);
           packet = DequeueFirstPacketByDst (dst);
         }
-      std::map<Mac48Address, EventId>::iterator i = m_preqTimeouts.find (dst);
+      std::map<Mac48Address, PreqEvent>::iterator i = m_preqTimeouts.find (dst);
       NS_ASSERT (i !=  m_preqTimeouts.end ());
+      m_routeDiscoveryTimeCallback (Simulator::Now () - i->second.whenScheduled);
       m_preqTimeouts.erase (i);
       return;
     }
@@ -997,7 +996,7 @@ HwmpProtocol::RetryPathDiscovery (Mac48Address dst, uint8_t numOfRetry)
     {
       i->second->RequestDestination (dst, originator_seqno, dst_seqno);
     }
-  m_preqTimeouts[dst] = Simulator::Schedule (
+  m_preqTimeouts[dst].preqTimeout = Simulator::Schedule (
       Scalar (2 * (numOfRetry + 1)) *  m_dot11MeshHWMPnetDiameterTraversalTime,
       &HwmpProtocol::RetryPathDiscovery, this, dst, numOfRetry);
 }
@@ -1112,7 +1111,7 @@ void HwmpProtocol::Statistics::Print (std::ostream & os) const
     "totalDropped=\"" << totalDropped << "\" "
     "initiatedPreq=\"" << initiatedPreq << "\" "
     "initiatedPrep=\"" << initiatedPrep << "\" "
-    "initiatedPerr=\"" << initiatedPerr << "\"" << std::endl;
+    "initiatedPerr=\"" << initiatedPerr << "\"/>" << std::endl;
 }
 void
 HwmpProtocol::Report (std::ostream & os) const
diff --git a/src/devices/mesh/dot11s/hwmp-protocol.h b/src/devices/mesh/dot11s/hwmp-protocol.h
index 98f56f45a..7218178b7 100644
--- a/src/devices/mesh/dot11s/hwmp-protocol.h
+++ b/src/devices/mesh/dot11s/hwmp-protocol.h
@@ -24,6 +24,7 @@
 #include "ns3/mesh-l2-routing-protocol.h"
 #include "ns3/nstime.h"
 #include "ns3/event-id.h"
+#include "ns3/traced-value.h"
 #include <vector>
 #include <map>
 
@@ -156,6 +157,8 @@ private:
    */
   bool DropDataFrame (uint32_t seqno, Mac48Address source);
   //\}
+  /// Route discovery time:
+  TracedCallback<Time> m_routeDiscoveryTimeCallback;
   ///\name Methods related to Queue/Dequeue procedures
   ///\{
   bool QueuePacket (QueuedPacket packet);
@@ -225,18 +228,20 @@ private:
   ///\{
   /// Data sequence number database
   std::map<Mac48Address, uint32_t> m_lastDataSeqno;
-  /// DSN databse
-  std::map<Mac48Address, uint32_t> m_lastHwmpSeqno;
-  /// Metric database
-  std::map<Mac48Address, uint32_t> m_lastHwmpMetric;
+  /// keeps HWMP seqno (first in pair) and HWMP metric (second in pair) for each address
+  std::map<Mac48Address, std::pair<uint32_t, uint32_t> > m_hwmpSeqnoMetricDatabase;
   ///\}
 
   /// Routing table
   Ptr<HwmpRtable> m_rtable;
 
   ///\name Timers:
-  ///\{
-  std::map<Mac48Address, EventId> m_preqTimeouts;
+  //\{
+  struct PreqEvent {
+    EventId preqTimeout;
+    Time whenScheduled;
+  };
+  std::map<Mac48Address, PreqEvent> m_preqTimeouts;
   EventId m_proactivePreqTimer;
   /// Random start in Proactive PREQ propagation
   Time m_randomStart;
diff --git a/src/devices/mesh/dot11s/peer-link.cc b/src/devices/mesh/dot11s/peer-link.cc
index 825685397..6e38ed46e 100644
--- a/src/devices/mesh/dot11s/peer-link.cc
+++ b/src/devices/mesh/dot11s/peer-link.cc
@@ -94,6 +94,10 @@ PeerLink::PeerLink () :
   m_peerMeshPointAddress (Mac48Address::GetBroadcast ()),
   m_localLinkId (0),
   m_peerLinkId (0),
+  m_assocId (0),
+  m_peerAssocId (0),
+  m_lastBeacon (Seconds (0)),
+  m_beaconInterval (Seconds (0)),
   m_packetFail (0),
   m_state (IDLE),
   m_retryCounter (0),
@@ -188,6 +192,12 @@ PeerLink::GetLocalAid () const
 {
   return m_assocId;
 }
+uint16_t
+PeerLink::GetPeerAid () const
+{
+  return m_peerAssocId;
+}
+
 Time
 PeerLink::GetLastBeacon () const
 {
diff --git a/src/devices/mesh/dot11s/peer-link.h b/src/devices/mesh/dot11s/peer-link.h
index 6db10c5ab..e26f0d1d9 100644
--- a/src/devices/mesh/dot11s/peer-link.h
+++ b/src/devices/mesh/dot11s/peer-link.h
@@ -74,11 +74,9 @@ public:
   void SetPeerMeshPointAddress (Mac48Address macaddr);
   void SetInterface (uint32_t interface);
   void SetLocalLinkId (uint16_t id);
-  //void SetPeerLinkId (uint16_t id);
   void SetLocalAid (uint16_t aid);
-  //void SetPeerAid (uint16_t aid);
+  uint16_t GetPeerAid () const;
   void SetBeaconTimingElement (IeBeaconTiming beaconTiming);
-  //void SetPeerLinkDescriptorElement (IePeerManagement peerLinkElement);
   Mac48Address GetPeerAddress () const;
   uint16_t GetLocalAid () const;
   Time GetLastBeacon () const;
diff --git a/src/devices/mesh/dot11s/peer-management-protocol-mac.cc b/src/devices/mesh/dot11s/peer-management-protocol-mac.cc
index f1277aab8..c7ab70a38 100644
--- a/src/devices/mesh/dot11s/peer-management-protocol-mac.cc
+++ b/src/devices/mesh/dot11s/peer-management-protocol-mac.cc
@@ -69,22 +69,16 @@ PeerManagementProtocolMac::Receive (Ptr<Packet> const_packet, const WifiMacHeade
     {
       MgtBeaconHeader beacon_hdr;
       packet->RemoveHeader (beacon_hdr);
-      //meshId.FindFirst (myBeacon);
-      bool meshBeacon = false;
       WifiInformationElementVector elements;
       packet->RemoveHeader(elements);
       Ptr<IeBeaconTiming> beaconTiming = DynamicCast<IeBeaconTiming> (elements.FindFirst (IE11S_BEACON_TIMING));
       Ptr<IeMeshId> meshId = DynamicCast<IeMeshId> (elements.FindFirst (IE11S_MESH_ID));
 
-      if ((beaconTiming != 0) && (meshId != 0))
+      if ((meshId != 0) && (m_protocol->GetMeshId ()->IsEqual (*meshId)))
         {
-          if (m_protocol->GetMeshId ()->IsEqual (*meshId))
-            {
-              meshBeacon = true;
-            }
+          m_protocol->ReceiveBeacon (m_ifIndex, header.GetAddr2 (), MicroSeconds (
+              beacon_hdr.GetBeaconIntervalUs ()), beaconTiming);
         }
-      m_protocol->UpdatePeerBeaconTiming (m_ifIndex, meshBeacon, *beaconTiming, header.GetAddr2 (),
-          Simulator::Now (), MicroSeconds (beacon_hdr.GetBeaconIntervalUs ()));
       // Beacon shall not be dropeed. May be needed to another plugins
       return true;
     }
@@ -190,9 +184,13 @@ PeerManagementProtocolMac::UpdateOutcomingFrame (Ptr<Packet> packet, WifiMacHead
 void
 PeerManagementProtocolMac::UpdateBeacon (MeshWifiBeacon & beacon) const
 {
-  Ptr<IeBeaconTiming> beaconTiming = m_protocol->GetBeaconTimingElement (m_ifIndex);
-  beacon.AddInformationElement (beaconTiming);
+  if (m_protocol->GetBeaconCollisionAvoidance ())
+    {
+      Ptr<IeBeaconTiming> beaconTiming = m_protocol->GetBeaconTimingElement (m_ifIndex);
+      beacon.AddInformationElement (beaconTiming);
+    }
   beacon.AddInformationElement (m_protocol->GetMeshId ());
+  m_protocol->NotifyBeaconSent (m_ifIndex, beacon.GetBeaconInterval ());
 }
 
 void
@@ -269,14 +267,6 @@ PeerManagementProtocolMac::GetAddress () const
       return Mac48Address::Mac48Address ();
     }
 }
-std::pair<Time, Time>
-PeerManagementProtocolMac::GetBeaconInfo () const
-{
-  std::pair<Time, Time> retval;
-  retval.first = m_parent->GetTbtt ();
-  retval.second = m_parent->GetBeaconInterval ();
-  return retval;
-}
 void
 PeerManagementProtocolMac::SetBeaconShift (Time shift)
 {
diff --git a/src/devices/mesh/dot11s/peer-management-protocol-mac.h b/src/devices/mesh/dot11s/peer-management-protocol-mac.h
index 46c727019..546104b1f 100644
--- a/src/devices/mesh/dot11s/peer-management-protocol-mac.h
+++ b/src/devices/mesh/dot11s/peer-management-protocol-mac.h
@@ -86,15 +86,8 @@ private:
   ///// Closes link when a proper number of successive transmissions have failed
   void TxError (WifiMacHeader const &hdr);
   void TxOk (WifiMacHeader const &hdr);
-  ///\name BCA functionallity:
-  ///\{
-  ///\brief Fills TBTT and beacon interval. Needed by BCA
-  ///functionallity
-  ///\param first in retval is TBTT
-  ///\param second in retval is beacon interval
-  std::pair<Time, Time> GetBeaconInfo () const;
+  ///BCA functionallity:
   void SetBeaconShift (Time shift);
-  ///\}
   void SetPeerManagerProtcol (Ptr<PeerManagementProtocol> protocol);
   void SendPeerLinkManagementFrame (
       Mac48Address peerAddress,
diff --git a/src/devices/mesh/dot11s/peer-management-protocol.cc b/src/devices/mesh/dot11s/peer-management-protocol.cc
index 7445965d0..63a512f63 100644
--- a/src/devices/mesh/dot11s/peer-management-protocol.cc
+++ b/src/devices/mesh/dot11s/peer-management-protocol.cc
@@ -55,18 +55,25 @@ PeerManagementProtocol::GetTypeId (void)
                       &PeerManagementProtocol::m_maxNumberOfPeerLinks),
                   MakeUintegerChecker<uint8_t> ()
                 )
-  .AddAttribute ( "MaxBeaconLossForBeaconTiming",
-                  "If maximum number of beacons were lost, station will not included in beacon timing element",
-                  UintegerValue (3),
+  .AddAttribute ( "MaxBeaconShiftValue",
+                  "Maximum number of TUs for beacon shifting",
+                  UintegerValue (15),
                   MakeUintegerAccessor (
-                      &PeerManagementProtocol::m_maxBeaconLostForBeaconTiming),
-                  MakeUintegerChecker<uint8_t> ()
+                      &PeerManagementProtocol::m_maxBeaconShift),
+                  MakeUintegerChecker<uint16_t> ()
                 )
+  .AddAttribute ( "EnableBeaconCollisionAvoidance",
+                  "Enable/Disable Beacon collision avoidance.",
+                  BooleanValue (true),
+                  MakeBooleanAccessor (
+                    &PeerManagementProtocol::SetBeaconCollisionAvoidance, &PeerManagementProtocol::GetBeaconCollisionAvoidance),
+                    MakeBooleanChecker ()
+                  )
                 ;
   return tid;
 }
 PeerManagementProtocol::PeerManagementProtocol () :
-  m_lastAssocId (0), m_lastLocalLinkId (1), m_maxBeaconLostForBeaconTiming (3)
+  m_lastAssocId (0), m_lastLocalLinkId (1), m_enableBca (true), m_maxBeaconShift (15)
 {
 }
 PeerManagementProtocol::~PeerManagementProtocol ()
@@ -87,13 +94,6 @@ PeerManagementProtocol::DoDispose ()
       j->second.clear ();
     }
   m_peerLinks.clear ();
-  //cleaning beacon structures:
-  for (BeaconInfoMap::iterator i = m_neighbourBeacons.begin (); i != m_neighbourBeacons.end (); i++)
-    {
-      i->second.clear ();
-    }
-  m_neighbourBeacons.clear ();
-
   m_plugins.clear ();
 }
 
@@ -128,89 +128,33 @@ PeerManagementProtocol::Install (Ptr<MeshPointDevice> mp)
 Ptr<IeBeaconTiming>
 PeerManagementProtocol::GetBeaconTimingElement (uint32_t interface)
 {
+  if (!GetBeaconCollisionAvoidance ())
+    {
+      return 0;
+    }
   Ptr<IeBeaconTiming> retval = Create<IeBeaconTiming> ();
-  BeaconInfoMap::iterator i = m_neighbourBeacons.find (interface);
-  if (i == m_neighbourBeacons.end ())
+  PeerLinksMap::iterator iface = m_peerLinks.find (interface);
+  NS_ASSERT (iface != m_peerLinks.end ());
+  for (PeerLinksOnInterface::iterator i = iface->second.begin (); i != iface->second.end (); i++)
     {
-      return retval;
-    }
-  bool cleaned = false;
-  while (!cleaned)
-    {
-      BeaconsOnInterface::iterator start = i->second.begin ();
-      for (BeaconsOnInterface::iterator j = start; j != i->second.end (); j++)
+      //If we do not know peer Assoc Id, we shall not add any info
+      //to a beacon timing element
+      if ((*i)->GetBeaconInterval () == Seconds (0))
         {
-          //check beacon loss and make a timing element
-          //if last beacon was m_maxBeaconLostForBeaconTiming beacons ago - we do not put it to the
-          //timing element
-          if ((j->second.referenceTbtt + j->second.beaconInterval * Scalar (m_maxBeaconLostForBeaconTiming))
-              < Simulator::Now ())
-            {
-              start = j;
-              i->second.erase (j);
-              break;
-            }
+          //No beacon was received, do not include to the beacon timing element
+          continue;
         }
-      cleaned = true;
-    }
-  for (BeaconsOnInterface::const_iterator j = i->second.begin (); j != i->second.end (); j++)
-    {
-      retval->AddNeighboursTimingElementUnit (j->second.aid, j->second.referenceTbtt,
-          j->second.beaconInterval);
+      retval->AddNeighboursTimingElementUnit ((*i)->GetLocalAid (), (*i)->GetLastBeacon (),
+          (*i)->GetBeaconInterval ());
     }
   return retval;
 }
-
 void
-PeerManagementProtocol::FillBeaconInfo (uint32_t interface, Mac48Address peerAddress, Time receivingTime,
-    Time beaconInterval)
+PeerManagementProtocol::ReceiveBeacon (uint32_t interface, Mac48Address peerAddress, Time beaconInterval, Ptr<IeBeaconTiming> timingElement)
 {
-  BeaconInfoMap::iterator i = m_neighbourBeacons.find (interface);
-  if (i == m_neighbourBeacons.end ())
-    {
-      BeaconsOnInterface newMap;
-      m_neighbourBeacons[interface] = newMap;
-    }
-  i = m_neighbourBeacons.find (interface);
-  BeaconsOnInterface::iterator j = i->second.find (peerAddress);
-  if (j == i->second.end ())
-    {
-      BeaconInfo newInfo;
-      newInfo.referenceTbtt = receivingTime;
-      newInfo.beaconInterval = beaconInterval;
-      newInfo.aid = m_lastAssocId++;
-      if (m_lastAssocId == 0xff)
-        {
-          m_lastAssocId = 0;
-        }
-      i->second[peerAddress] = newInfo;
-    }
-  else
-    {
-      j->second.referenceTbtt = receivingTime;
-      j->second.beaconInterval = beaconInterval;
-    }
-}
-
-void
-PeerManagementProtocol::UpdatePeerBeaconTiming (uint32_t interface, bool meshBeacon,
-    IeBeaconTiming timingElement, Mac48Address peerAddress, Time receivingTime, Time beaconInterval)
-{
-  FillBeaconInfo (interface, peerAddress, receivingTime, beaconInterval);
-  if (!meshBeacon)
-    {
-      return;
-    }
-  //BCA:
-  PeerManagementProtocolMacMap::iterator plugin = m_plugins.find (interface);
-  NS_ASSERT (plugin != m_plugins.end ());
-  Time shift = GetNextBeaconShift (interface);
-  if (TimeToTu (shift) != 0)
-    {
-      plugin->second->SetBeaconShift (shift);
-    }
   //PM STATE Machine
   //Check that a given beacon is not from our interface
+  Simulator::Schedule (beaconInterval - TuToTime (m_maxBeaconShift + 1), &PeerManagementProtocol::DoShiftBeacon, this, interface);
   for (PeerManagementProtocolMacMap::const_iterator i = m_plugins.begin (); i != m_plugins.end (); i++)
     {
       if (i->second->GetAddress () == peerAddress)
@@ -219,21 +163,19 @@ PeerManagementProtocol::UpdatePeerBeaconTiming (uint32_t interface, bool meshBea
         }
     }
   Ptr<PeerLink> peerLink = FindPeerLink (interface, peerAddress);
-  if (peerLink != 0)
-    {
-      peerLink->SetBeaconTimingElement (timingElement);
-      peerLink->SetBeaconInformation (receivingTime, beaconInterval);
-    }
-  else
+  if (peerLink == 0)
     {
       if (ShouldSendOpen (interface, peerAddress))
         {
-          peerLink = InitiateLink (interface, peerAddress, Mac48Address::GetBroadcast (), receivingTime,
-              beaconInterval);
-          peerLink->SetBeaconTimingElement (timingElement);
+          peerLink = InitiateLink (interface, peerAddress, Mac48Address::GetBroadcast ());
           peerLink->MLMEActivePeerLinkOpen ();
         }
     }
+  peerLink->SetBeaconInformation (Simulator::Now (), beaconInterval);
+  if (GetBeaconCollisionAvoidance ())
+    {
+      peerLink->SetBeaconTimingElement (*PeekPointer (timingElement));
+    }
 }
 
 void
@@ -248,8 +190,7 @@ PeerManagementProtocol::ReceivePeerLinkFrame (uint32_t interface, Mac48Address p
       bool reject = !(ShouldAcceptOpen (interface, peerAddress, reasonCode));
       if (peerLink == 0)
         {
-          peerLink = InitiateLink (interface, peerAddress, peerMeshPointAddress, Simulator::Now (), Seconds (
-              1.0));
+          peerLink = InitiateLink (interface, peerAddress, peerMeshPointAddress);
         }
       if (!reject)
         {
@@ -307,26 +248,9 @@ PeerManagementProtocol::TransmissionSuccess (uint32_t interface, Mac48Address pe
 }
 Ptr<PeerLink>
 PeerManagementProtocol::InitiateLink (uint32_t interface, Mac48Address peerAddress,
-    Mac48Address peerMeshPointAddress, Time lastBeacon, Time beaconInterval)
+    Mac48Address peerMeshPointAddress)
 {
   Ptr<PeerLink> new_link = CreateObject<PeerLink> ();
-  if (m_lastLocalLinkId == 0xff)
-    {
-      m_lastLocalLinkId = 0;
-    }
-  //find a beacon entry
-  BeaconInfoMap::iterator beaconsOnInterface = m_neighbourBeacons.find (interface);
-  if (beaconsOnInterface == m_neighbourBeacons.end ())
-    {
-      FillBeaconInfo (interface, peerAddress, lastBeacon, beaconInterval);
-    }
-  beaconsOnInterface = m_neighbourBeacons.find (interface);
-  BeaconsOnInterface::iterator beacon = beaconsOnInterface->second.find (peerAddress);
-  if (beacon == beaconsOnInterface->second.end ())
-    {
-      FillBeaconInfo (interface, peerAddress, lastBeacon, beaconInterval);
-    }
-  beacon = beaconsOnInterface->second.find (peerAddress);
   //find a peer link  - it must not exist
   if (FindPeerLink (interface, peerAddress) != 0)
     {
@@ -337,17 +261,17 @@ PeerManagementProtocol::InitiateLink (uint32_t interface, Mac48Address peerAddre
   NS_ASSERT (plugin != m_plugins.end ());
   PeerLinksMap::iterator iface = m_peerLinks.find (interface);
   NS_ASSERT (iface != m_peerLinks.end ());
-  new_link->SetLocalAid (beacon->second.aid);
+  new_link->SetLocalAid (m_lastAssocId++);
   new_link->SetInterface (interface);
   new_link->SetLocalLinkId (m_lastLocalLinkId++);
   new_link->SetPeerAddress (peerAddress);
   new_link->SetPeerMeshPointAddress (peerMeshPointAddress);
-  new_link->SetBeaconInformation (lastBeacon, beaconInterval);
   new_link->SetMacPlugin (plugin->second);
   new_link->MLMESetSignalStatusCallback (MakeCallback (&PeerManagementProtocol::PeerLinkStatus, this));
   iface->second.push_back (new_link);
   return new_link;
 }
+
 Ptr<PeerLink>
 PeerManagementProtocol::FindPeerLink (uint32_t interface, Mac48Address peerAddress)
 {
@@ -377,13 +301,14 @@ PeerManagementProtocol::SetPeerLinkStatusCallback (
 {
   m_peerStatusCallback = cb;
 }
+
 std::vector<Mac48Address>
-PeerManagementProtocol::GetActiveLinks (uint32_t interface)
+PeerManagementProtocol::GetPeers (uint32_t interface) const
 {
   std::vector<Mac48Address> retval;
-  PeerLinksMap::iterator iface = m_peerLinks.find (interface);
+  PeerLinksMap::const_iterator iface = m_peerLinks.find (interface);
   NS_ASSERT (iface != m_peerLinks.end ());
-  for (PeerLinksOnInterface::iterator i = iface->second.begin (); i != iface->second.end (); i++)
+  for (PeerLinksOnInterface::const_iterator i = iface->second.begin (); i != iface->second.end (); i++)
     {
       if ((*i)->LinkIsEstab ())
         {
@@ -392,6 +317,21 @@ PeerManagementProtocol::GetActiveLinks (uint32_t interface)
     }
   return retval;
 }
+
+std::vector< Ptr<PeerLink> >
+PeerManagementProtocol::GetPeerLinks () const
+{
+  std::vector< Ptr<PeerLink> > links;
+
+  for (PeerLinksMap::const_iterator iface = m_peerLinks.begin (); iface != m_peerLinks.end (); ++iface)
+    {
+      for (PeerLinksOnInterface::const_iterator i = iface->second.begin ();
+      i != iface->second.end (); i++)
+        if ((*i)->LinkIsEstab ())
+          links.push_back (*i);
+    }
+  return links;
+}
 bool
 PeerManagementProtocol::IsActiveLink (uint32_t interface, Mac48Address peerAddress)
 {
@@ -407,6 +347,7 @@ PeerManagementProtocol::ShouldSendOpen (uint32_t interface, Mac48Address peerAdd
 {
   return (m_stats.linksTotal <= m_maxNumberOfPeerLinks);
 }
+
 bool
 PeerManagementProtocol::ShouldAcceptOpen (uint32_t interface, Mac48Address peerAddress,
     PmpReasonCode & reasonCode)
@@ -418,56 +359,70 @@ PeerManagementProtocol::ShouldAcceptOpen (uint32_t interface, Mac48Address peerA
     }
   return true;
 }
-Time
-PeerManagementProtocol::GetNextBeaconShift (uint32_t interface)
+
+void
+PeerManagementProtocol::DoShiftBeacon (uint32_t interface)
 {
-  //REMINDER:: in timing element  1) last beacon reception time is measured in units of 256 microseconds
-  //                              2) beacon interval is mesured in units of 1024 microseconds
-  //                              3) hereafter TU = 1024 microseconds
-  //So, the shift is a random integer variable uniformly distributed in [-15;-1] U [1;15]
-  static int maxShift = 15;
-  static int minShift = 1;
-  UniformVariable randomSign (-1, 1);
-  UniformVariable randomShift (minShift, maxShift);
+  if (!GetBeaconCollisionAvoidance ())
+    {
+      return;
+    }
+  // If beacon interval is equal to the neighbor's one and one o more beacons received
+  // by my neighbor coincide with my beacon - apply random uniformly distributed shift from
+  // [-m_maxBeaconShift, m_maxBeaconShift] except 0.
+  UniformVariable beaconShift (-m_maxBeaconShift, m_maxBeaconShift);
   PeerLinksMap::iterator iface = m_peerLinks.find (interface);
   NS_ASSERT (iface != m_peerLinks.end ());
-  PeerManagementProtocolMacMap::iterator plugin = m_plugins.find (interface);
+  PeerManagementProtocolMacMap::const_iterator plugin = m_plugins.find (interface);
   NS_ASSERT (plugin != m_plugins.end ());
-  std::pair<Time, Time> myBeacon = plugin->second->GetBeaconInfo ();
-  if (Simulator::Now () + TuToTime (maxShift) > myBeacon.first + myBeacon.second)
+  std::map<uint32_t, Time>::const_iterator lastBeacon = m_lastBeacon.find (interface);
+  std::map<uint32_t, Time>::const_iterator beaconInterval = m_beaconInterval.find (interface);
+  if ((lastBeacon == m_lastBeacon.end ()) || (beaconInterval == m_beaconInterval.end ()))
     {
-      return MicroSeconds (0);
+      return;
+    }
+  if (TuToTime (m_maxBeaconShift) > m_beaconInterval[interface])
+    {
+      NS_FATAL_ERROR ("Wrong beacon shift parameters");
+      return;
     }
   for (PeerLinksOnInterface::iterator i = iface->second.begin (); i != iface->second.end (); i++)
     {
       IeBeaconTiming::NeighboursTimingUnitsList neighbours;
-      if ((*i)->LinkIsIdle ())
-        {
-          continue;
-        }
       neighbours = (*i)->GetBeaconTimingElement ().GetNeighboursTimingElementsList ();
       //Going through all my timing elements and detecting future beacon collisions
       for (IeBeaconTiming::NeighboursTimingUnitsList::const_iterator j = neighbours.begin (); j
           != neighbours.end (); j++)
         {
-          //We apply MBAC only if beacon Intervals are equal
-          if ((*j)->GetBeaconInterval () == TimeToTu (myBeacon.second))
+          if ((*i)->GetPeerAid () == (*j)->GetAid ())
             {
-              //Apply MBCA if future beacons may coinside
-              if ((TimeToTu (myBeacon.first) - ((*j)->GetLastBeacon () / 4)) % ((*j)->GetBeaconInterval ())
-                  == 0)
-                {
-                  int beaconShift = randomShift.GetInteger (minShift, maxShift) * ((randomSign.GetValue ()
-                      >= 0) ? 1 : -1);
-                  NS_LOG_DEBUG ("Apply MBCA: Shift value = " << beaconShift << " beacon TUs");
-                  //Do not shift to the past!
-                  return (TuToTime (beaconShift) + Simulator::Now () < myBeacon.first) ? TuToTime (
-                      beaconShift) : TuToTime (0);
-                }
+              // I am present at neighbour's list of neighbors
+              continue;
             }
+          //Beacon interval is stored in TU's
+          if (((*j)->GetBeaconInterval ()) != TimeToTu(beaconInterval->second))
+            {
+              continue;
+            }
+          //Timing element keeps beacon receiving times in 256us units, TU=1024us
+          if ((int) ((int)(*j)->GetLastBeacon () / 4 - (int)TimeToTu (lastBeacon->second)) % TimeToTu (
+              beaconInterval->second)
+              != 0)
+            {
+              continue;
+            }
+              int shift = 0;
+              do
+                {
+                  shift = (int) beaconShift.GetValue ();
+                }
+              while (shift == 0);
+              PeerManagementProtocolMacMap::iterator plugin = m_plugins.find (interface);
+              NS_ASSERT (plugin != m_plugins.end ());
+              plugin->second->SetBeaconShift (TuToTime (shift));
+              return;
         }
     }
-  return MicroSeconds (0);
 }
 Time
 PeerManagementProtocol::TuToTime (uint32_t x)
@@ -533,6 +488,12 @@ PeerManagementProtocol::GetAddress ()
 {
   return m_address;
 }
+void
+PeerManagementProtocol::NotifyBeaconSent (uint32_t interface, Time beaconInterval)
+{
+  m_lastBeacon[interface] = Simulator::Now ();
+  m_beaconInterval[interface] = beaconInterval;
+}
 PeerManagementProtocol::Statistics::Statistics (uint16_t t) :
   linksTotal (t), linksOpened (0), linksClosed (0)
 {
@@ -574,6 +535,16 @@ PeerManagementProtocol::ResetStats ()
     }
 }
 
+void
+PeerManagementProtocol::SetBeaconCollisionAvoidance (bool enable)
+{
+  m_enableBca = enable;
+}
+bool
+PeerManagementProtocol::GetBeaconCollisionAvoidance () const
+{
+  return m_enableBca;
+}
 } // namespace dot11s
 } //namespace ns3
 
diff --git a/src/devices/mesh/dot11s/peer-management-protocol.h b/src/devices/mesh/dot11s/peer-management-protocol.h
index e0dea2664..0a23fb1e5 100644
--- a/src/devices/mesh/dot11s/peer-management-protocol.h
+++ b/src/devices/mesh/dot11s/peer-management-protocol.h
@@ -74,25 +74,12 @@ public:
    */
   Ptr<IeBeaconTiming> GetBeaconTimingElement (uint32_t interface);
   /**
-   * \brief When we receive a beacon from peer-station, we remember
-   * its beacon timing element (needed for peer choosing mechanism),
-   * and remember beacon timers - last beacon and beacon interval to
-   * detect beacon loss and cancel links
-   * \param interface is a interface on which beacon was received
-   * \param meshBeacon indicates whether the beacon is mesh beacon or not.
-   * \param timingElement is a timing element of remote beacon
-   * \param peerAddress is an address where a beacon was received from
-   * \param receivingTime is a time when beacon was received
-   * \param beaconInterval is a beacon interval of received beacon
+   * \brief To initiate peer link we must notify about received beacon
+   * \param interface the interface where a beacon was received from
+   * \param peerAddress address of station, which sent a beacon
+   * \param beaconInterval beacon interval (needed by beacon loss counter)
    */
-  void UpdatePeerBeaconTiming (
-      uint32_t interface,
-      bool meshBeacon,
-      IeBeaconTiming timingElement,
-      Mac48Address peerAddress,
-      Time receivingTime,
-      Time beaconInterval
-      );
+  void ReceiveBeacon (uint32_t interface, Mac48Address peerAddress, Time beaconInterval, Ptr<IeBeaconTiming> beaconTiming);
   //\}
   /**
    * \brief Methods that handle Peer link management frames
@@ -137,16 +124,26 @@ public:
    */
   bool IsActiveLink (uint32_t interface, Mac48Address peerAddress);
   //\}
-  ///\brief Needed by external module to do MLME
-  Ptr<PeerLink> FindPeerLink (uint32_t interface, Mac48Address peerAddress);
+  ///\name Interface to other protocols (MLME)
+  //\{
+  /// Set peer link status change callback
   void SetPeerLinkStatusCallback (Callback<void, Mac48Address, Mac48Address, uint32_t, bool> cb);
-  std::vector<Mac48Address> GetActiveLinks (uint32_t interface);
-  ///\brief needed by plugins to set global source address
+  /// Find active peer link by my interface and peer interface MAC
+  Ptr<PeerLink> FindPeerLink (uint32_t interface, Mac48Address peerAddress);
+  /// Get list of all active peer links
+  std::vector < Ptr<PeerLink> > GetPeerLinks () const;
+  /// Get list of active peers of my given interface
+  std::vector<Mac48Address> GetPeers (uint32_t interface) const;
+  /// Get mesh point address. TODO this used by plugins only. Now MAC plugins can ask MP addrress directly from main MAC
   Mac48Address GetAddress ();
-  ///\brief Needed to fill mesh configuration
   uint8_t GetNumberOfLinks ();
   void SetMeshId (std::string s);
   Ptr<IeMeshId> GetMeshId () const;
+  /// Enable or disable beacon collision avoidance
+  void SetBeaconCollisionAvoidance (bool enable);
+  bool GetBeaconCollisionAvoidance () const;
+  /// Notify about beacon send event, needed to schedule BCA
+  void NotifyBeaconSent (uint32_t interface, Time beaconInterval);
   ///\brief: Report statistics
   void Report (std::ostream &) const;
   void ResetStats ();
@@ -177,16 +174,10 @@ private:
   PeerManagementProtocol& operator= (const PeerManagementProtocol &);
   PeerManagementProtocol (const PeerManagementProtocol &);
 
-  /**
-   * \brief Fills information of received beacon. Needed to form own beacon timing element
-   */
-  void FillBeaconInfo (uint32_t interface, Mac48Address peerAddress, Time receivingTime, Time beaconInterval);
   Ptr<PeerLink> InitiateLink (
       uint32_t interface,
       Mac48Address peerAddress,
-      Mac48Address peerMeshPointAddress,
-      Time lastBeacon,
-      Time beaconInterval
+      Mac48Address peerMeshPointAddress
       );
   /**
    * \name External peer-chooser
@@ -200,7 +191,7 @@ private:
    */
   void PeerLinkStatus (uint32_t interface, Mac48Address peerAddress, Mac48Address peerMeshPointAddres, PeerLink::PeerState ostate, PeerLink::PeerState nstate);
   ///\brief BCA
-  Time GetNextBeaconShift (uint32_t interface);
+  void DoShiftBeacon (uint32_t interface);
   /**
    * \name Time<-->TU converters:
    * \{
@@ -212,16 +203,19 @@ private:
   PeerManagementProtocolMacMap m_plugins;
   Mac48Address m_address;
   Ptr<IeMeshId> m_meshId;
-  /**
-   * \name Information related to beacons:
-   * \{
-   */
-  BeaconInfoMap m_neighbourBeacons;
-  ///\}
+  
   uint16_t m_lastAssocId;
   uint16_t m_lastLocalLinkId;
   uint8_t m_maxNumberOfPeerLinks;
-  uint8_t m_maxBeaconLostForBeaconTiming;
+  /// Flag which enables BCA
+  bool m_enableBca;
+  /// Beacon can be shifted at [-m_maxBeaconShift; +m_maxBeaconShift] TUs
+  uint16_t m_maxBeaconShift;
+  ///Last beacon at each interface
+  std::map<uint32_t, Time> m_lastBeacon;
+  ///Beacon interval at each interface
+  std::map<uint32_t, Time> m_beaconInterval;
+
   /**
    * \name Peer Links
    * \{
diff --git a/src/devices/mesh/mesh-wifi-beacon.cc b/src/devices/mesh/mesh-wifi-beacon.cc
index a1300e9f8..420282141 100644
--- a/src/devices/mesh/mesh-wifi-beacon.cc
+++ b/src/devices/mesh/mesh-wifi-beacon.cc
@@ -35,6 +35,11 @@ MeshWifiBeacon::AddInformationElement (Ptr<WifiInformationElement> ie)
   m_elements.AddInformationElement (ie);
 }
 
+Time
+MeshWifiBeacon::GetBeaconInterval () const
+{
+  return MicroSeconds (m_header.GetBeaconIntervalUs ());
+}
 
 Ptr<Packet>
 MeshWifiBeacon::CreatePacket ()
diff --git a/src/devices/mesh/mesh-wifi-beacon.h b/src/devices/mesh/mesh-wifi-beacon.h
index f05d9f483..19d78c1f4 100644
--- a/src/devices/mesh/mesh-wifi-beacon.h
+++ b/src/devices/mesh/mesh-wifi-beacon.h
@@ -58,6 +58,8 @@ public:
    * \param mpAddress is mesh point address
    */
   WifiMacHeader CreateHeader (Mac48Address address, Mac48Address mpAddress);
+  ///Returns a beacon interval of wifi beacon
+  Time GetBeaconInterval () const;
   /// Create frame = { beacon header + all information elements sorted by ElementId () }
   Ptr<Packet> CreatePacket ();
 
diff --git a/src/helper/dot11s-installer.cc b/src/helper/dot11s-installer.cc
index fb85888e6..ac901a911 100644
--- a/src/helper/dot11s-installer.cc
+++ b/src/helper/dot11s-installer.cc
@@ -75,7 +75,7 @@ Dot11sStack::InstallStack (Ptr<MeshPointDevice> mp)
   //Install interaction between HWMP and Peer management protocol:
   //PeekPointer()'s to avoid circular Ptr references
   pmp->SetPeerLinkStatusCallback (MakeCallback (&HwmpProtocol::PeerLinkStatus, PeekPointer (hwmp)));
-  hwmp->SetNeighboursCallback (MakeCallback (&PeerManagementProtocol::GetActiveLinks, PeekPointer (pmp)));
+  hwmp->SetNeighboursCallback (MakeCallback (&PeerManagementProtocol::GetPeers, PeekPointer (pmp)));
   return true;
 }
 void