diff --git a/model/annotated-topology-reader.cc b/model/annotated-topology-reader.cc
index a9b66bf..d6bbad1 100644
--- a/model/annotated-topology-reader.cc
+++ b/model/annotated-topology-reader.cc
@@ -315,4 +315,22 @@
     }
 }
 
+void
+AnnotatedTopologyReader::SavePositions (const std::string &file) const
+{
+  ofstream os (file.c_str (), ios::trunc);
+  os << "router\n";
+  
+  for (NodeContainer::Iterator node = m_nodes.Begin ();
+       node != m_nodes.End ();
+       node++)
+    {
+      std::string name = Names::FindName (*node);
+      Ptr<MobilityModel> mobility = (*node)->GetObject<MobilityModel> ();
+      Vector position = mobility->GetPosition ();
+
+      os << name << "\t" << "unknown" << "\t" << -position.y << "\t" << position.x << "\n";
+    }
+}
+
 }