To simulate a Tree Topology in OMNeT++ has includes to configure the nodes in the sequential order in which each node except the root has one parent and probably multiple children. The communication in this topology tracks a parent-child relationship, and data usually flows up or down the tree structure.
We focus on customizing the nodes linked to your projects so that you receive the best results from phdprime.com to conduct out simulation in Tree Topology Projects Using the OMNeT++ program, we will walk you through the process in detail and provide the best results.
Here’s how we can simulate a Tree Topology using OMNeT++ step-by-step:
Steps to Simulate Tree Topology Projects in OMNeT++
- Define the Network Structure (NED File)
The tree topology is defined in a .ned file. In the tree structure, the root node sits at the top and is associated to intermediate nodes, which are further associated to leaf nodes.
Sample NED File (TreeTopology.ned)
network TreeTopology
{
submodules:
// Define nodes in the tree
root: Node {
@display(“p=300,100”); // Position at the top
}
// Level 1
intermediate1: Node {
@display(“p=200,200”);
}
intermediate2: Node {
@display(“p=400,200”);
}
// Level 2 (Leaf nodes)
leaf1: Node {
@display(“p=150,300”);
}
leaf2: Node {
@display(“p=250,300”);
}
leaf3: Node {
@display(“p=350,300”);
}
leaf4: Node {
@display(“p=450,300”);
}
connections allowunconnected:
// Connect the root to intermediate nodes
root.out++ –> intermediate1.in++;
root.out++ –> intermediate2.in++;
// Connect intermediate nodes to leaf nodes
intermediate1.out++ –> leaf1.in++;
intermediate1.out++ –> leaf2.in++;
intermediate2.out++ –> leaf3.in++;
intermediate2.out++ –> leaf4.in++;
}
- Create Node Module (Node.ned)
Each node will have input and output gates to interact with its parent and children. Describe a simple node that will manage message passing up and down the tree.
Sample Node Module (Node.ned)
simple Node
{
parameters:
@display(“i=device/laptop”); // Use an icon to represent the node
gates:
input in[];
output out[];
}
- Implement Node Behavior (Node.cc)
The nodes in the tree will manage message forwarding to their children or transmit data up to their parent, relay on the direction of communication.
Sample Node Behavior (Node.cc)
#include <omnetpp.h>
using namespace omnetpp;
class Node : public cSimpleModule
{
private:
bool isRoot; // Determines if the node is a root node
bool isLeaf; // Determines if the node is a leaf node
protected:
virtual void initialize() override;
virtual void handleMessage(cMessage *msg) override;
void sendDown(cMessage *msg); // Function to send message to children
void sendUp(cMessage *msg); // Function to send message to parent
};
Define_Module(Node);
void Node::initialize()
{
// Identify if the node is root or leaf based on gates
isRoot = (strcmp(getName(), “root”) == 0);
isLeaf = (gateSize(“out”) == 0);
if (isRoot) {
// Root node sends an initial message down the tree
cMessage *msg = new cMessage(“Message from Root”);
scheduleAt(simTime() + 1.0, msg);
}
}
void Node::handleMessage(cMessage *msg)
{
if (isLeaf) {
// Leaf nodes send the message back up the tree
EV << getName() << ” received: ” << msg->getName() << ” and sending up to parent.\n”;
sendUp(msg);
} else if (isRoot) {
// Root processes the received message
EV << getName() << ” received a message back from a leaf node.\n”;
delete msg;
} else {
// Intermediate nodes forward messages between parent and children
if (msg->isSelfMessage()) {
// Forward the message down the tree
sendDown(msg);
} else {
// Forward the message up the tree
sendUp(msg);
}
}
}
void Node::sendDown(cMessage *msg)
{
// Send message to all children (broadcasting the message)
for (int i = 0; i < gateSize(“out”); i++) {
cMessage *dupMsg = msg->dup(); // Duplicate message for each child
EV << getName() << ” sending down message to child.\n”;
send(dupMsg, “out”, i);
}
delete msg;
}
void Node::sendUp(cMessage *msg)
{
// Forward message to parent (first input gate)
EV << getName() << ” sending up message to parent.\n”;
send(msg, “in”, 0);
}
- Run the Simulation
To simulate the feature of the tree topology, generate an omnetpp.ini file to describe simulation parameters.
Sample OMNeT++ Configuration (omnetpp.ini)
network = TreeTopology
sim-time-limit = 10s
# Define the number of gates for each node
*.root.numGates = 2 # Root has two children
*.intermediate*.numGates = 2 # Intermediate nodes have two children
*.leaf*.numGates = 0 # Leaf nodes have no children
- Visualize and Analyse
After running the simulation:
- Message Flow: we should monitor the message originating from the root node and propagating down to all leaf nodes. Leaf nodes should transmit responses back up the tree to the root.
- Metrics: Assess on the performance based on message delivery time, latency among nodes, and the flow of data between parent and child nodes.
- Enhance the Simulation
Here are some improvements we can add to make the simulation more complex and realistic:
- Bi-directional Communication: Apply logic to manage messages going both ways among parents and children, simulating real-time bidirectional communication in a tree.
- Failure of Nodes: Replicate node failures by disconnecting nodes or dropping messages and monitoring on how the tree acts as when part of the structure is missing.
- Load Balancing: execute load balancing at the intermediate nodes to replicate scenarios in which traffic needs to be evenly dispersed via child nodes.
- Multicast/Broadcast: we need to replicate multicast communication, in which the root or an intermediate node broadcasts a message to a subset of the tree instead of all nodes.
Example of Bi-directional Communication Enhancement
we can execute bidirectional communication in which a node transmit data to both its parent and its children, using diverse messages for each.
void Node::handleMessage(cMessage *msg)
{
if (isLeaf) {
// Leaf nodes send a response back to their parent
EV << getName() << ” received: ” << msg->getName() << ” and responding to parent.\n”;
sendUp(msg);
} else if (isRoot) {
// Root processes the messages and can initiate a new message down
EV << getName() << ” received a message from a leaf node.\n”;
cMessage *newMsg = new cMessage(“New message from Root”);
sendDown(newMsg);
delete msg;
} else {
// Intermediate nodes forward messages between parent and children
if (strcmp(msg->getName(), “New message from Root”) == 0) {
// Forward the new message down to children
sendDown(msg);
} else {
// Forward the response up to parent
sendUp(msg);
}
}
}
With the help of this procedure you can obtain the knowledge and can be able to simulate the Tree Topology projects in OMNeT++ tool. Additional specific details regarding the Tree Topology projects also provided.
