Adding SpringMobilityModel to adjust positions of nodes in large
topologies
Inspired by http://en.wikipedia.org/wiki/Force-based_algorithms_%28graph_drawing%29
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