mobility: Adds a simple mobility example

RELEASE_NOTES.md

@@ -34,6 +34,7 @@ been tested on Linux. The latest known version to work with ns-3 is cppyy==3.1.2
 - (wifi) - The `ApWifiMac` provides new attributes (`CwMinsForSta`, `CwMaxsForSta`, `AifsnsForSta` and `TxopLimitsForSta`) to define the EDCA access parameters to include in the EDCA Parameter Set advertised to associated stations
 - (wifi) - The `WifiMacHelper` provides a `SetChannelAccessManager` and a `SetFrameExchangeManager` methods to configure attributes of `ChannelAccessManager` and `FrameExchangeManager` objects, respectively
 - (wifi) - Simulation duration and data rate parameters of existing wifi examples changed to use Time and DataRate types
+- (mobility) !1986 - Adds simple constant-mobility-example
 
 ### Bugs fixed
 

src/mobility/examples/CMakeLists.txt

@@ -1,5 +1,6 @@
 set(base_examples
     bonnmotion-ns2-example
+    constant-mobility-example
     main-random-topology
     main-random-walk
     ns2-mobility-trace

src/mobility/examples/constant-mobility-example.cc

@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2024 Tokushima University, Tokushima, Japan.
+ *
+ * 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: Alberto Gallegos Ramonet <alramonet@is.tokushima-u.ac.jp>
+ */
+
+/*
+   This example shows a comparison between node mobility set with and without the
+   use of helpers. Furthermore it shows a simple way to update the node positions.
+   More advanced position allocations and mobility patterns can be achieve with
+   the use of other helpers.
+
+   In this example, node N1 moves to the right in 3 different instances
+   during the simulation while node N0 remains static. A trace is used to print a
+   message when movement is detected in node N1.
+
+               10 m         {Sec 2}      10m         {Sec 4}      10 m      {Sec 6}
+   N0,N1 --------------------->N1--------------------> N1 ------------------> N1
+  (0,0,0)     Move Right    (10,0,0)   Move Right   (20,0,0)   Move Right   (30,0,0)
+*/
+
+#include <ns3/mobility-module.h>
+#include <ns3/node.h>
+#include <ns3/simulator.h>
+
+using namespace ns3;
+
+void
+CourseChangeCallback(Ptr<const MobilityModel> mobility)
+{
+    std::cout << Simulator::Now().As(Time::S) << " Movement detected (Node "
+              << mobility->GetObject<Node>()->GetId() << ")!\n";
+}
+
+void
+MoveNode(Ptr<Node> node, const Vector& pos)
+{
+    Ptr<MobilityModel> mobilityModel = node->GetObject<MobilityModel>();
+    NS_ASSERT_MSG(mobilityModel, "Node doesn't have a mobility model");
+    mobilityModel->SetPosition(pos);
+
+    Vector newPos = mobilityModel->GetPosition();
+
+    std::cout << Simulator::Now().As(Time::S) << " Node " << node->GetId() << " | MoveRight, Pos ("
+              << newPos.x << "," << newPos.y << "," << newPos.z << ")\n";
+}
+
+int
+main(int argc, char* argv[])
+{
+    // Method 1: Install the mobility model using the helper
+    //           The helper creates and installs the mobility to a single node
+    //           or multiple nodes in a node container. Different helpers might
+    //           have additional options.
+
+    NodeContainer nodeContainer(1);
+
+    MobilityHelper mobility;
+    mobility.SetMobilityModel("ns3::ConstantPositionMobilityModel");
+
+    Ptr<ListPositionAllocator> positionAllocator = CreateObject<ListPositionAllocator>();
+    positionAllocator->Add(Vector(0, 0, 0));
+
+    mobility.SetPositionAllocator(positionAllocator);
+    Ptr<Node> n0 = nodeContainer.Get(0);
+    mobility.Install(n0);
+
+    // Method 2: Install the mobility manually
+    //           You need to manually create both, the node object and the mobility object.
+    //           After that, you aggregate the mobility to a node.
+
+    Ptr<Node> n1 = CreateObject<Node>();
+    Ptr<ConstantPositionMobilityModel> mob1 = CreateObject<ConstantPositionMobilityModel>();
+    n1->AggregateObject(mob1);
+    mob1->SetPosition(Vector(0, 0, 0));
+
+    // Set the mobility trace hook to node n1 to keep track of its movements
+    mob1->TraceConnectWithoutContext("CourseChange", MakeBoundCallback(&CourseChangeCallback));
+
+    // Schedule movements to node n1
+    Simulator::ScheduleWithContext(n1->GetId(), Seconds(2.0), &MoveNode, n1, Vector(10, 0, 0));
+
+    Simulator::ScheduleWithContext(n1->GetId(), Seconds(4.0), &MoveNode, n1, Vector(20, 0, 0));
+
+    Simulator::ScheduleWithContext(n1->GetId(), Seconds(6.0), &MoveNode, n1, Vector(30, 0, 0));
+
+    Simulator::Stop(Seconds(10));
+    Simulator::Run();
+
+    Simulator::Destroy();
+    return 0;
+}