To simulate Delay-Tolerant Networking (DTN) protocols are created to manage an intermittent connectivity and long delays among the network nodes that are normal in challenging environments such as deep-space communication, disaster recovery, and vehicular networks. DTNs use a store-and-forward mechanism in which nodes are temporarily store packets (bundles) until they can forward them to the next node when a connection becomes obtainable.
To simulate DTN protocols using OMNeT++, we can either execute the protocol manually or incorporate an existing DTN protocol. OMNeT++ offers a flexible framework to mimic such protocols, and we can expand it with DTN-specific behaviour. Some external modules, such as INET or the DTN simulator TheONE, may be obtainable for integration, via we may require to execute the DTN routing logic if it is not obtainable out-of-the-box. For best simulation assistance contact phdprime.com for best results.
Here’s we provide simple guide for you to simulate the DTN Protocols using OMNeT++:
Steps to Simulate DTN Protocols Projects in OMNeT++
Step 1: Install OMNeT++ and INET Framework
Make certain that OMNeT++ and the INET framework are installed, as they offer a foundation for wireless communication and mobility simulation.
- Download OMNeT++: OMNeT++ official website
- Download INET Framework: INET Framework
INET delivers models for wireless communication and mobility that are necessary for replicating a DTN scenario.
Step 2: Understand DTN Architecture and Concepts
In DTN, the communication is often intermittent, and data packets (bundles) are stored until a forwarding opportunity rises. A few key ideas of DTN protocols contain:
- Store-and-Forward: Bundles are stored at a node until an appropriate forwarding opportunity is obtainable.
- Custody Transfer: The responsibility of delivering a bundle is transmitted to the next node.
- Opportunistic Routing: DTN routing depends on nodes’ encounters to provide data to the destination.
Popular DTN routing protocols encompass Epidemic Routing, Spray and Wait, and PROPHET (Probabilistic Routing Protocol using History of Encounters).
Step 3: Set Up the Network Topology in the NED File
Describe a mobile ad hoc network (MANET)-style topology within the NED file, in which nodes are communicate opportunistically. This topology will be replicated the intermittent connectivity among nodes.
network DTNNetwork
{
submodules:
mobileNode[10]: WirelessHost { // 10 mobile nodes using DTN protocol
@display(“p=100,100”);
}
}
- mobileNode[10] denotes the 10 mobile nodes, each capable of storing and forwarding data according to DTN principles.
Step 4: Configure Mobility and Wireless Settings in omnetpp.ini
DTNs provide contain involve mobility, in which nodes are move and come into contact with one another. We can use a mobility model to replicate node movement and wireless communication settings:
[Config DTNSimulation]
network = DTNNetwork
sim-time-limit = 1000s
# Mobility model (Random waypoint mobility for nodes in a DTN)
*.mobileNode[*].mobility.typename = “RandomWaypointMobility”
*.mobileNode[*].mobility.speed = uniform(1mps, 5mps) # Speed range
*.mobileNode[*].mobility.startPosition = uniform(0m, 1000m)
# Wireless settings (typical for DTNs using short-range communication)
*.mobileNode[*].wlan[0].radio.transmitter.communicationRange = 100m # Communication range
*.mobileNode[*].wlan[0].bitrate = 54Mbps
This configuration sets up node mobility and wireless communication. The mobility model (e.g., RandomWaypointMobility) mimics nodes moving randomly in the simulation area, making an intermittent connectivity.
Step 5: Implement a DTN Protocol
If a DTN protocol such as Epidemic Routing or Spray and Wait is not already obtainable then we will require to execute it manually. DTN protocols based on opportunistic contacts among the nodes for communication, and each node required to store and forward bundles when it meets another node.
Here’s a simple outline for executing Epidemic Routing in C++:
- Bundle Creation: When a node generates data then it stores the informations as a bundle.
- Forwarding: When two nodes are come into contact then they swap bundles. Bundles are sent to the next node, potentially attaining the destination.
Epidemic Routing Protocol Class
class EpidemicRouting : public cSimpleModule
{
protected:
std::vector<cMessage *> bundleQueue; // Queue of bundles waiting for transmission
std::set<int> encounteredNodes; // Set of nodes this node has encountered
virtual void initialize() override {
// Initialize Epidemic Routing parameters (e.g., buffer size, timeout)
}
virtual void handleMessage(cMessage *msg) override {
if (msg->isSelfMessage()) {
// Handle periodic checks for node encounters
checkForEncounters();
} else {
// Handle incoming bundle or control message
handleIncomingBundle(msg);
}
}
void checkForEncounters();
void forwardBundlesToEncounteredNode(int nodeId);
void handleIncomingBundle(cMessage *bundle);
};
In the checkForEncounters method, we will verify for nodes in communication range. When a new node is met then bundles are exchanged among the nodes.
Step 6: Simulate Traffic and Bundles in the DTN
DTN traffic is normally generated in the form of bundles, in which data is transmitted in bursts or intermittently. Here’s an instance of how to generate DTN bundles among the nodes:
# Configure bundle generation for mobileNode[0] to mobileNode[1]
*.mobileNode[0].numApps = 1
*.mobileNode[0].app[0].typename = “BundleApp”
*.mobileNode[0].app[0].localAddress = “1.0.0.1”
*.mobileNode[0].app[0].destAddresses = “1.0.0.2”
*.mobileNode[0].app[0].bundleSize = 1024 # Bundle size in bytes
*.mobileNode[0].app[0].interval = exponential(10s) # Generate a bundle every ~10 seconds
*.mobileNode[0].app[0].startTime = 5s # Start bundle generation after 5 seconds
*.mobileNode[1].numApps = 1
*.mobileNode[1].app[0].typename = “BundleApp”
*.mobileNode[1].app[0].localAddress = “1.0.0.2”
Step 7: Simulate Opportunistic Contacts between Nodes
To replicate an opportunistic routing, nodes will require to swap the bundles when they come into contact. We can be executed it in the checkForEncounters function, in which the distance among two nodes is verify, and if they are within communication range then the bundles are exchanged:
void EpidemicRouting::checkForEncounters() {
// Logic to check if nodes are within communication range and exchange bundles
for (int i = 0; i < numNodes; i++) {
if (isNodeInRange(i)) {
forwardBundlesToEncounteredNode(i);
}
}
}
bool EpidemicRouting::isNodeInRange(int nodeId) {
// Check if the node with id nodeId is within communication range
return true; // Placeholder for actual distance calculation
}
void EpidemicRouting::forwardBundlesToEncounteredNode(int nodeId) {
// Send all stored bundles to the newly encountered node
for (auto &bundle : bundleQueue) {
sendDirect(bundle, “wlan[0].radioIn”, nodeId);
}
}
Step 8: Run the Simulation
When the DTN protocol and network configuration are configure:
- Build and compile the project in OMNeT++.
- Run the simulation through the OMNeT++ GUI or command line.
- Monitor DTN behavior: We can be envisioned the node movement, bundle forwarding, and node encounters within the OMNeT++ GUI.
Step 9: Analyze Simulation Results
The simulation tool OMNeT++ generates .sca and .vec files are encompassing simulation results. Significant performance parameters for DTNs contain:
- Bundle delivery ratio: The ratio of delivered bundles to the entire bundles are generated.
- End-to-end delay: The time it takes for bundles to attain the destination that can be substantial in DTNs.
- Storage overhead: The total of storage used by nodes to store bundles before forwarding them.
- Energy consumption: The energy consumed by nodes because of bundle transmission, mobility, and storage.
Utilize OMNeT++’s result analysis tools to plot these parameters and acquire insights into the performance of the DTN protocol.
Step 10: Experiment with Different DTN Protocols
When we have a simple DTN protocol (like Epidemic Routing), we can test with other DTN routing protocols like:
- Spray and Wait: A protocol, which limits the amount of copies of a message in the network.
- PROPHET: A probabilistic routing protocol, which utilizes the history of encounters and transitivity to decide forwarding paths.
Each protocol has distinct trade-offs such as delivery ratio, overhead, and delay.’
We had given general approach, featuring relevant instances for DTN Protocols projects, was simulated and analysed through OMNeT++ analysis tool. Moreover, we will be presented further specifics on this projects.
