diff --git a/examples/abilene-topology.cc b/examples/abilene-topology.cc
index 75a4b99..a96daf7 100644
--- a/examples/abilene-topology.cc
+++ b/examples/abilene-topology.cc
@@ -30,6 +30,7 @@
 #include <iostream>
 #include <sstream>
 #include "ns3/annotated-topology-reader.h"
+#include "../utils/spring-mobility-helper.h"
 
 using namespace ns3;
 using namespace std;
@@ -80,6 +81,7 @@
   // --------------------------------------------
     
   AnnotatedTopologyReader reader ("/abilene");
+  reader.SetMobilityModel ("ns3::SpringMobilityModel");
   reader.SetFileName (input);
     
   NodeContainer nodes = reader.Read ();
@@ -90,6 +92,8 @@
       return -1;
     }
 
+  SpringMobilityHelper::InstallSprings (reader.LinksBegin (), reader.LinksEnd ());
+
   // InternetStackHelper stack;
   // Ipv4GlobalRoutingHelper ipv4RoutingHelper ("ns3::Ipv4GlobalRoutingOrderedNexthops");
   // stack.SetRoutingHelper (ipv4RoutingHelper);
diff --git a/examples/abilene-topology.txt b/examples/abilene-topology.txt
index 5eb607d..4672859 100644
--- a/examples/abilene-topology.txt
+++ b/examples/abilene-topology.txt
@@ -1,7 +1,7 @@
 router
 #name	city	latitude	longitude
 ATLA-M5	Atlanta_GA	33.750000	-84.383300
-ATLAng	Atlanta_GA	33.750000	-84.383300
+ATLAng	Atlanta_GA	33.850000	-84.483300
 CHINng	Chicago_IL	41.833300	-87.616700
 DNVRng	Denver_CO	40.750000	-105.000000
 HSTNng	Houston_TX	29.770031	-95.517364
diff --git a/examples/sprint-topology.cc b/examples/sprint-topology.cc
index 5efffeb..3a53c35 100644
--- a/examples/sprint-topology.cc
+++ b/examples/sprint-topology.cc
@@ -31,43 +31,81 @@
 #include "ns3/rocketfuel-topology-reader.h"
 
 using namespace ns3;
+using namespace std;
 
 NS_LOG_COMPONENT_DEFINE ("CcnxSprintTopology");
 
 int 
 main (int argc, char *argv[])
 {
-    Packet::EnableChecking();
-    Packet::EnablePrinting();
-    std::string weights ("./src/NDNabstraction/examples/sprint.weights");
-    std::string latencies ("./src/NDNabstraction/examples/sprint.latencies");
+  // Packet::EnableChecking();
+  // Packet::EnablePrinting();
+  string weights ("./src/NDNabstraction/examples/sprint.weights");
+  string latencies ("./src/NDNabstraction/examples/sprint.latencies");
     
-    // ------------------------------------------------------------
-    // -- Read topology data.
-    // --------------------------------------------
-    
-    RocketfuelWeightsReader reader;
+  Time finishTime = Seconds (2.0);
+  string animationFile;
+  string strategy = "ns3::CcnxFloodingStrategy";
+  CommandLine cmd;
+  cmd.AddValue ("finish", "Finish time", finishTime);
+  cmd.AddValue ("netanim", "NetAnim filename", animationFile);
+  cmd.AddValue ("strategy", "CCNx forwarding strategy", strategy);
+  cmd.AddValue ("weights", "Weights file", weights);
+  cmd.AddValue ("latencies", "Latencies file", latencies);
+  cmd.Parse (argc, argv);
 
-    reader.SetFileName (weights);
-    reader.SetFileType (RocketfuelWeightsReader::WEIGHTS);    
-    NodeContainer nodes = reader.Read ();
-
-    reader.SetFileName (latencies);
-    reader.SetFileType (RocketfuelWeightsReader::LATENCIES);    
-    reader.Read ();
+  // ------------------------------------------------------------
+  // -- Read topology data.
+  // --------------------------------------------
     
-    if (reader.LinksSize () == 0)
+  RocketfuelWeightsReader reader ("/sprint");
+  reader.SetBoundingBox (0, 0, 400, 250);
+
+  reader.SetFileName (weights);
+  reader.SetFileType (RocketfuelWeightsReader::WEIGHTS);    
+  NodeContainer nodes = reader.Read ();
+
+  reader.SetFileName (latencies);
+  reader.SetFileType (RocketfuelWeightsReader::LATENCIES);    
+  reader.Read ();
+    
+  reader.Commit ();
+  if (reader.LinksSize () == 0)
     {
-        NS_LOG_ERROR ("Problems reading the topology file. Failing.");
-        return -1;
+      NS_LOG_ERROR ("Problems reading the topology file. Failing.");
+      return -1;
     }
     
-    NS_LOG_INFO("Nodes = " << nodes.GetN());
-    NS_LOG_INFO("Links = " << reader.LinksSize ());
+  NS_LOG_INFO("Nodes = " << nodes.GetN());
+  NS_LOG_INFO("Links = " << reader.LinksSize ());
     
-    NS_LOG_INFO ("Run Simulation.");
-    Simulator::Run ();
-    Simulator::Destroy ();
-    NS_LOG_INFO ("Done.");
-    return 0;
+  InternetStackHelper stack;
+  Ipv4GlobalRoutingHelper ipv4RoutingHelper ("ns3::Ipv4GlobalRoutingOrderedNexthops");
+  stack.SetRoutingHelper (ipv4RoutingHelper);
+  stack.Install (nodes);
+
+  reader.AssignIpv4Addresses (Ipv4Address ("10.0.0.0"));
+
+  // Install CCNx stack
+  NS_LOG_INFO ("Installing CCNx stack");
+  CcnxStackHelper ccnxHelper;
+  ccnxHelper.SetForwardingStrategy (strategy);
+  ccnxHelper.EnableLimits (false, Seconds(0.1));
+  ccnxHelper.SetDefaultRoutes (true);
+  ccnxHelper.InstallAll ();
+
+  // // Populate FIB based on IPv4 global routing controller
+  // ccnxHelper.InstallFakeGlobalRoutes ();
+  // ccnxHelper.InstallRouteTo (Names::Find<Node> ("/sprint", "San+Jose,+CA4062"));
+
+  // Simulator::Schedule (Seconds (1.0), PrintFIBs);
+  // PrintFIBs ();
+
+  Simulator::Stop (finishTime);
+
+  NS_LOG_INFO ("Run Simulation.");
+  Simulator::Run ();
+  Simulator::Destroy ();
+  NS_LOG_INFO ("Done.");
+  return 0;
 }
diff --git a/model/annotated-topology-reader.cc b/model/annotated-topology-reader.cc
index eb56339..6553f86 100644
--- a/model/annotated-topology-reader.cc
+++ b/model/annotated-topology-reader.cc
@@ -58,6 +58,8 @@
   , m_randY (0, 100.0)
 {
   NS_LOG_FUNCTION (this);
+
+  // SetMobilityModel ("ns3::ConstantPositionMobilityModel");
 }
     
 void
@@ -69,6 +71,13 @@
   m_randY = UniformVariable (uly, lry);
 }
 
+void
+AnnotatedTopologyReader::SetMobilityModel (const std::string &model)
+{
+  NS_LOG_FUNCTION (this << model);
+  m_mobilityFactory.SetTypeId (model);
+}
+
 AnnotatedTopologyReader::~AnnotatedTopologyReader ()
 {
   NS_LOG_FUNCTION (this);
@@ -77,14 +86,15 @@
 Ptr<Node>
 AnnotatedTopologyReader::CreateNode (const std::string name)
 {
-  return CreateNode (name, m_randX.GetValue (), m_randX.GetValue ());
+  return CreateNode (name, m_randX.GetValue (), m_randY.GetValue ());
 }
 
 Ptr<Node>
 AnnotatedTopologyReader::CreateNode (const std::string name, double posX, double posY)
 {
+  NS_LOG_FUNCTION (this << name << posX << posY);
   Ptr<Node> node = CreateObject<Node> ();
-  Ptr<ConstantPositionMobilityModel> loc = CreateObject<ConstantPositionMobilityModel> ();
+  Ptr<MobilityModel> loc = DynamicCast<MobilityModel> (m_mobilityFactory.Create ());
   node->AggregateObject (loc);
 
   loc->SetPosition (Vector (posX, posY, 0));
@@ -144,9 +154,9 @@
       // NS_LOG_DEBUG ("Input: [" << line << "]");
       
       istringstream lineBuffer (line);
-      string from, to, capacity, metric;
+      string from, to, capacity, metric, delay, queueSizeNode1, queueSizeNode2;
 
-      lineBuffer >> from >> to >> capacity >> metric;
+      lineBuffer >> from >> to >> capacity >> metric >> delay >> queueSizeNode1 >> queueSizeNode2;
 
       if (processedLinks[to].size () != 0 &&
           processedLinks[to].find (from) != processedLinks[to].end ())
@@ -164,9 +174,13 @@
       
       link.SetAttribute ("DataRate", capacity);
       link.SetAttribute ("OSPF", metric);
-      // link.SetAttribute ("Delay", delay);
-      // link.SetAttribute ("QueueSizeNode1", queueSizeNode1);
-      // link.SetAttribute ("QueueSizeNode2", queueSizeNode2);
+
+      if (!delay.empty ())
+          link.SetAttribute ("Delay", delay);
+      if (!queueSizeNode1.empty ())
+        link.SetAttribute ("QueueSizeNode1", queueSizeNode1);
+      if (!queueSizeNode2.empty ())
+        link.SetAttribute ("QueueSizeNode2", queueSizeNode2);
 
       AddLink (link);
       NS_LOG_DEBUG ("New link " << from << " <==> " << to << " / " << capacity << "Kbps with " << metric << " metric");
@@ -202,6 +216,7 @@
 {
   BOOST_FOREACH (const Link &link, m_linksList)
     {
+      NS_LOG_DEBUG ("OSPF: " << link.GetAttribute ("OSPF"));
       uint16_t metric = boost::lexical_cast<uint16_t> (link.GetAttribute ("OSPF"));
         
       {
@@ -230,40 +245,33 @@
 AnnotatedTopologyReader::ApplySettings ()
 {
   PointToPointHelper p2p;
-    
-  // temporary queue, will be changed later
-  p2p.SetQueue ("ns3::DropTailQueue",
-                "MaxPackets", StringValue("100"));
 
   BOOST_FOREACH (Link &link, m_linksList)
     {
       string tmp;
 
-      NS_LOG_INFO ("DataRate = " + link.GetAttribute("DataRate")+"Kbps");
-      p2p.SetDeviceAttribute ("DataRate", StringValue(link.GetAttribute("DataRate")+"Kbps"));
+      if (link.GetAttributeFailSafe ("DataRate", tmp))
+        {
+          NS_LOG_INFO ("DataRate = " + link.GetAttribute("DataRate")+"Kbps");
+          p2p.SetDeviceAttribute ("DataRate", StringValue(link.GetAttribute("DataRate")+"Kbps"));
+        }
 
       if (link.GetAttributeFailSafe("Delay", tmp))
         {
           NS_LOG_INFO ("Delay = " + link.GetAttribute("Delay")+"ms");
           p2p.SetChannelAttribute ("Delay", StringValue(link.GetAttribute("Delay")+"ms"));
         }
-      else
-        {
-          NS_LOG_INFO ("Default delay 1ms");
-          p2p.SetChannelAttribute ("Delay", StringValue("1ms"));
-        }
         
       NetDeviceContainer nd = p2p.Install(link.GetFromNode (), link.GetToNode ());
       link.SetNetDevices (nd.Get (0), nd.Get (1));
 
-      // NS_LOG_INFO ("Queue: " << link.GetAttribute("QueueSizeNode1") << " <==> " << link.GetAttribute("QueueSizeNode2"));
-
       if (link.GetAttributeFailSafe("QueueSizeNode1", tmp))
         {
           PointerValue txQueueFrom;
           link.GetFromNetDevice ()->GetAttribute ("TxQueue", txQueueFrom);
           NS_ASSERT (txQueueFrom.Get<DropTailQueue> () != 0);
 
+          NS_LOG_INFO ("QueueFrom: " << link.GetAttribute("QueueSizeNode1"));
           txQueueFrom.Get<DropTailQueue> ()->SetAttribute ("MaxPackets", StringValue (link.GetAttribute("QueueSizeNode1")));
         }
       
@@ -273,6 +281,7 @@
           link.GetToNetDevice ()->GetAttribute ("TxQueue", txQueueTo);
           NS_ASSERT (txQueueTo.Get<DropTailQueue> () != 0);
         
+          NS_LOG_INFO ("QueueTo: " << link.GetAttribute("QueueSizeNode2"));
           txQueueTo.Get<DropTailQueue> ()->SetAttribute ("MaxPackets", StringValue (link.GetAttribute("QueueSizeNode2")));
         }
     }
diff --git a/model/annotated-topology-reader.h b/model/annotated-topology-reader.h
index 06bbe2a..4bacd2a 100644
--- a/model/annotated-topology-reader.h
+++ b/model/annotated-topology-reader.h
@@ -23,6 +23,7 @@
 
 #include "ns3/topology-reader.h"
 #include "ns3/random-variable.h"
+#include "ns3/object-factory.h"
 
 namespace ns3 
 {
@@ -69,6 +70,9 @@
   void
   SetBoundingBox (double ulx, double uly, double lrx, double lry);
 
+  void
+  SetMobilityModel (const std::string &model);
+
 protected:
   Ptr<Node>
   CreateNode (const std::string name);
@@ -76,7 +80,7 @@
   Ptr<Node>
   CreateNode (const std::string name, double posX, double posY);
   
-private:
+protected:
   /**
    * \brief This method applies setting to corresponding nodes and links
    * NetDeviceContainer must be allocated
@@ -94,6 +98,8 @@
 
   UniformVariable m_randX;
   UniformVariable m_randY;
+
+  ObjectFactory m_mobilityFactory;
 };
 
 }
diff --git a/model/rocketfuel-weights-reader.cc b/model/rocketfuel-weights-reader.cc
index ac7f6b1..448464e 100644
--- a/model/rocketfuel-weights-reader.cc
+++ b/model/rocketfuel-weights-reader.cc
@@ -46,6 +46,7 @@
 
 #include <boost/foreach.hpp>
 #include <boost/lexical_cast.hpp>
+#include "../utils/spring-mobility-helper.h"
 
 #include <iomanip>
 #include <set>
@@ -56,9 +57,11 @@
 
 namespace ns3 {
     
-RocketfuelWeightsReader::RocketfuelWeightsReader ()
+RocketfuelWeightsReader::RocketfuelWeightsReader (const std::string &path/*=""*/)
+  : AnnotatedTopologyReader (path)
 {
   NS_LOG_FUNCTION (this);
+  SetMobilityModel ("ns3::SpringMobilityModel");
 }
     
 RocketfuelWeightsReader::~RocketfuelWeightsReader ()
@@ -138,8 +141,11 @@
       switch (m_inputType)
         {
         case WEIGHTS:
-          link->SetAttribute ("OSPF", attribute);
-          break;
+          {
+            double metric = boost::lexical_cast<double> (attribute);
+            link->SetAttribute ("OSPF", boost::lexical_cast<string> (metric*2));
+            break;
+          }
         case LATENCIES:
           link->SetAttribute ("Delay", attribute);
           break;
@@ -156,8 +162,34 @@
     }
         
   topgen.close ();
-  NS_LOG_INFO ("Rocketfuel topology created with " << nodes.GetN () << " nodes and " << LinksSize () << " links");
+
+  if (!repeatedRun)
+    {
+      NS_LOG_INFO ("Rocketfuel topology created with " << nodes.GetN () << " nodes and " << LinksSize () << " links");
+    }
   return nodes;
 }
-    
+
+void
+RocketfuelWeightsReader::Commit ()
+{
+  ApplySettings ();
+
+  SpringMobilityHelper::InstallSprings (LinksBegin (), LinksEnd ());
+}
+
+
+// void
+// RocketfuelWeightsReader::Cheat (NodeContainer &nodes)
+// {
+//   double epsilon = 1;
+
+//   for (NodeContainer::Iterator i = nodes.Begin ();
+//        i != nodes.End ();
+//        i++)
+//     {
+      
+//     }  
+// }
+
 } /* namespace ns3 */
diff --git a/model/rocketfuel-weights-reader.h b/model/rocketfuel-weights-reader.h
index 2b73c11..ecf4905 100644
--- a/model/rocketfuel-weights-reader.h
+++ b/model/rocketfuel-weights-reader.h
@@ -39,7 +39,7 @@
 class RocketfuelWeightsReader : public AnnotatedTopologyReader
 {
 public:
-  RocketfuelWeightsReader ();
+  RocketfuelWeightsReader (const std::string &path="");
   virtual ~RocketfuelWeightsReader ();
 
   void
@@ -55,7 +55,11 @@
    *
    * \return the container of the nodes created (or empty container if there was an error)
    */
-  virtual NodeContainer Read (void);
+  virtual NodeContainer 
+  Read (void);
+
+  void
+  Commit ();
 
   enum
     {
@@ -63,6 +67,9 @@
       LATENCIES
     };
 
+  // void
+  // Cheat (NodeContainer &nodes);
+
 private:
   RocketfuelWeightsReader (const RocketfuelWeightsReader&);
   RocketfuelWeightsReader& operator= (const RocketfuelWeightsReader&);
diff --git a/utils/spring-mobility-helper.cc b/utils/spring-mobility-helper.cc
new file mode 100644
index 0000000..5e4b4f6
--- /dev/null
+++ b/utils/spring-mobility-helper.cc
@@ -0,0 +1,51 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2006, 2007 INRIA
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#include "spring-mobility-helper.h"
+#include "spring-mobility-model.h"
+
+namespace ns3 {
+
+void
+SpringMobilityHelper::InstallSprings (Ptr<Node> node1, Ptr<Node> node2)
+{
+  Ptr<SpringMobilityModel> model1, model2;
+  model1 = node1->GetObject<SpringMobilityModel> ();
+  model2 = node2->GetObject<SpringMobilityModel> ();
+  
+  NS_ASSERT (model1 != 0 && model2 != 0);
+
+  model1->AddSpring (model2);
+  model2->AddSpring (model1);
+}
+
+void
+SpringMobilityHelper::InstallSprings (TopologyReader::ConstLinksIterator first, 
+				      TopologyReader::ConstLinksIterator end)
+{
+  for (; first != end; first++)
+    {
+      InstallSprings (first->GetFromNode (), 
+		      first->GetToNode ());
+    }
+}
+
+} // namespace ns3
+
diff --git a/utils/spring-mobility-helper.h b/utils/spring-mobility-helper.h
new file mode 100644
index 0000000..7285d25
--- /dev/null
+++ b/utils/spring-mobility-helper.h
@@ -0,0 +1,45 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2006, 2007 INRIA
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+#ifndef SPRING_MOBILITY_HELPER_H
+#define SPRING_MOBILITY_HELPER_H
+
+#include "ns3/topology-reader.h"
+
+namespace ns3 {
+
+/**
+ * \ingroup mobility
+ *
+ * \brief 
+ */
+class SpringMobilityHelper
+{
+public:
+  static void
+  InstallSprings (Ptr<Node> node1, Ptr<Node> node2);
+
+  static void
+  InstallSprings (TopologyReader::ConstLinksIterator first, 
+                  TopologyReader::ConstLinksIterator end);
+};
+
+} // namespace ns3
+
+#endif // SPRING_MOBILITY_HELPER_H
diff --git a/utils/spring-mobility-model.cc b/utils/spring-mobility-model.cc
new file mode 100644
index 0000000..5fb968b
--- /dev/null
+++ b/utils/spring-mobility-model.cc
@@ -0,0 +1,188 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2006, 2007 INRIA
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+#include "spring-mobility-model.h"
+#include "ns3/simulator.h"
+#include "ns3/double.h"
+#include "ns3/log.h"
+#include "ns3/node-list.h"
+#include "ns3/node.h"
+
+#include <boost/foreach.hpp>
+
+NS_LOG_COMPONENT_DEFINE ("SpringMobilityModel");
+
+namespace ns3 {
+
+NS_OBJECT_ENSURE_REGISTERED (SpringMobilityModel);
+
+double SpringMobilityModel::m_totalKineticEnergy = 0.0;
+
+const double COLOUMB_K = 200; 
+
+TypeId SpringMobilityModel::GetTypeId (void)
+{
+  static TypeId tid = TypeId ("ns3::SpringMobilityModel")
+    .SetParent<MobilityModel> ()
+    .AddConstructor<SpringMobilityModel> ()
+    .AddAttribute ("Epsilon", "Bound for kinetic energy when system is considered stable",
+                   DoubleValue (1000.0),
+                   MakeDoubleAccessor (&SpringMobilityModel::m_epsilon),
+                   MakeDoubleChecker<double> ())
+    .AddAttribute ("NodeMass", "Node mass",
+                   DoubleValue (10),
+                   MakeDoubleAccessor (&SpringMobilityModel::m_nodeMass),
+                   MakeDoubleChecker<double> ())
+    .AddAttribute ("NodeCharge", "Node charge",
+                   DoubleValue (2),
+                   MakeDoubleAccessor (&SpringMobilityModel::m_nodeCharge),
+                   MakeDoubleChecker<double> ())
+    .AddAttribute ("SpringNormalLength", "Normal length of spring length",
+                   DoubleValue (10),
+                   MakeDoubleAccessor (&SpringMobilityModel::m_springNormalLength),
+                   MakeDoubleChecker<double> ())
+    .AddAttribute ("SpringConstant", "Spring constant",
+                   DoubleValue (0.2),
+                   MakeDoubleAccessor (&SpringMobilityModel::m_springConstant),
+                   MakeDoubleChecker<double> ())
+    .AddAttribute ("DampingFactor", "Dumping factor",
+                   DoubleValue (0.6),
+                   MakeDoubleAccessor (&SpringMobilityModel::m_dampingFactor),
+                   MakeDoubleChecker<double> ())
+    ;
+  
+  return tid;
+}
+
+SpringMobilityModel::SpringMobilityModel ()
+  : m_position (0,0,0)
+  , m_velocity (0,0,0)
+  , m_stable (false)
+{
+}
+
+SpringMobilityModel::~SpringMobilityModel ()
+{
+}
+
+void
+SpringMobilityModel::AddSpring (Ptr<MobilityModel> node)
+{
+  m_springs.push_back (node);
+}
+
+void
+SpringMobilityModel::DoStart ()
+{
+  // m_updateEvent = Simulator::Schedule (Seconds(0.05), &SpringMobilityModel::Update, this);
+
+  // Simulator::Schedule (Seconds(2.0), &SpringMobilityModel::Test, this);
+}
+
+void
+SpringMobilityModel::Update () const
+{
+  // NS_LOG_FUNCTION (this << m_stable << m_position << m_velocity);
+  if (m_stable) return;
+  Time now = Simulator::Now ();
+
+  if (now <= m_lastTime)
+    {
+      m_lastTime = now;
+      return;
+    }
+
+  double time_step_s = (now - m_lastTime).ToDouble (Time::S);
+  m_lastTime = now;
+
+  Vector force (0.0, 0.0, 0.0);
+
+  for (NodeList::Iterator node = NodeList::Begin ();
+       node != NodeList::End ();
+       node++)
+    {
+      if ((*node)->GetId () == GetObject<Node> ()->GetId ()) continue;
+      Ptr<SpringMobilityModel> model = (*node)->GetObject<SpringMobilityModel> ();
+      if (model == 0) continue;
+      if (model == this) continue;
+
+      double distance = GetDistanceFrom (model);
+      if (distance < 0.1) continue;
+
+      Vector direction = (GetPosition () - model->GetPosition ()) / distance; // direction vector of size 1, force trying to take nodes apart
+
+      force += direction * COLOUMB_K * m_nodeCharge * m_nodeCharge / distance / distance;
+    }
+
+  BOOST_FOREACH (Ptr<MobilityModel> model, m_springs)
+    {
+      double distance = GetDistanceFrom (model);
+      Vector direction = (model->GetPosition () - GetPosition ()) / distance; // direction vector of size 1, force trying to take nodes closer, if they are more than distance apart
+
+      force += direction * (- m_springNormalLength + distance) / m_springConstant;
+    }
+
+  // NS_LOG_DEBUG ("force: " << force);
+
+  // subtract previous value of kinetic energy for the node
+  double velocityValue = CalculateDistance (m_velocity, Vector(0,0,0)); 
+  m_totalKineticEnergy -= m_nodeMass * velocityValue * velocityValue;
+
+  // Correct velocity and position
+  m_velocity = (m_velocity + force * time_step_s) * m_dampingFactor;
+  m_position += m_velocity * time_step_s;
+
+  // Add new value for the kinetic energy
+  velocityValue = CalculateDistance (m_velocity, Vector(0,0,0)); 
+  m_totalKineticEnergy += m_nodeMass * velocityValue * velocityValue;
+
+  if (m_totalKineticEnergy < m_epsilon)
+    {
+      m_stable = true;
+      NS_LOG_INFO ("Stabilized with " << m_totalKineticEnergy);
+    }
+
+  NotifyCourseChange ();
+  // m_updateEvent = Simulator::Schedule (Seconds(0.05), &SpringMobilityModel::Update, this);
+}
+
+Vector
+SpringMobilityModel::DoGetPosition (void) const
+{
+  // NS_LOG_FUNCTION (this << m_position);
+  Update ();
+  
+  return m_position;
+}
+void 
+SpringMobilityModel::DoSetPosition (const Vector &position)
+{
+  // NS_LOG_FUNCTION (this << position);
+  m_position = position;
+
+  NotifyCourseChange ();
+  m_stable = false;
+}
+Vector
+SpringMobilityModel::DoGetVelocity (void) const
+{
+  return m_velocity;
+}
+
+} // namespace ns3
diff --git a/utils/spring-mobility-model.h b/utils/spring-mobility-model.h
new file mode 100644
index 0000000..553ab9d
--- /dev/null
+++ b/utils/spring-mobility-model.h
@@ -0,0 +1,94 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2006, 2007 INRIA
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: 
+ */
+#ifndef SPRING_MOBILITY_MODEL_H
+#define SPRING_MOBILITY_MODEL_H
+
+#include "ns3/mobility-model.h"
+#include "ns3/nstime.h"
+#include "ns3/event-id.h"
+
+namespace ns3 {
+
+/**
+ * \ingroup mobility
+ *
+ * \brief 
+ */
+class SpringMobilityModel : public MobilityModel 
+{
+public:
+  static TypeId GetTypeId (void);
+
+  /**
+   * Create a position located at coordinates (0,0,0) with velocity (0,0,0)
+   */
+  SpringMobilityModel ();
+  virtual ~SpringMobilityModel ();
+
+  /**
+   * \brief Attach node by a spring
+   * \param node MobilityModel layer of the attaching node
+   */
+  void
+  AddSpring (Ptr<MobilityModel> node);
+
+private:
+  // from Object
+  virtual void
+  DoStart ();
+
+  // from MobilityModel
+  virtual Vector 
+  DoGetPosition (void) const;
+
+  virtual void 
+  DoSetPosition (const Vector &position);
+
+  virtual Vector 
+  DoGetVelocity (void) const;
+
+  // Updating positions
+  void 
+  Update (void) const;
+
+private:
+  double m_epsilon;
+
+  double m_nodeMass;
+  double m_nodeCharge;
+  double m_springNormalLength;
+  double m_springConstant;
+  double m_dampingFactor;
+
+  static double m_totalKineticEnergy;  
+  
+  mutable Vector m_position;
+  mutable Vector m_velocity;
+  mutable bool m_stable;
+  mutable Time m_lastTime;
+
+  EventId m_updateEvent;
+
+  std::list<Ptr<MobilityModel> > m_springs;
+};
+
+} // namespace ns3
+
+#endif // SPRING_MOBILITY_MODEL_H