How to Start Star Topology Projects Using OMNeT++

To start a Star Topology Simulation using OMNeT++ which is a direct way for designing a network environment in which every node interact via a central node. This topology often utilised within wireless networks, sensor networks, or small LAN configurations. We follow these steps to start and configure a Star Topology Project in OMNeT++:

Steps to Start Star Topology Projects in OMNeT++

  1. Understand Star Topology
  • Definition: Every node is linked to a central node like a hub, switch, or access point in star topology.
  • Characteristics:
    • Centralized interaction via a single hub.
    • It is simple for configuring however it susceptible to central node failure.
  • Applications:
    • Wireless sensor networks (WSNs).
    • Local Area Networks (LANs).
  1. Set Up OMNeT++ and INET Framework
  • Install OMNeT++: We can download and set up OMNeT++ on the system.
  • Install INET Framework:
    • INET framework offers modules for wired and wireless interaction that are crucial to replicate the star topology.
  1. Define Project Scope

Step 3.1: Goals

  • Replicate a star topology in which nodes are transmitted data via a central hub.
  • Measure the performance parameters such as:
    • Packet delivery ratio.
    • Latency.
    • Throughput.

Step 3.2: Metrics

  • Packet Delivery Ratio (PDR): Rate of packets that are effectively distributed.
  • Latency: Duration for packets, attaining its destination node.
  • Throughput: Bandwidth consumption within the network.
  1. Design the Star Topology

Create a network topology including several nodes that are associated to a central hub.

Example .ned File:

network StarTopology {

submodules:

hub: Router;                // Central node (hub)

node[5]: StandardHost;      // Peripheral nodes

connections:

node[0].ethg++ <–> EthernetLink <–> hub.ethg++;

node[1].ethg++ <–> EthernetLink <–> hub.ethg++;

node[2].ethg++ <–> EthernetLink <–> hub.ethg++;

node[3].ethg++ <–> EthernetLink <–> hub.ethg++;

node[4].ethg++ <–> EthernetLink <–> hub.ethg++;

}

  1. Configure Node Behavior

Step 5.1: Data Transmission

Replicate traffic among the nodes and hub to utilise UdpBasicApp of INET framework.

Example .ini File Configuration:

[Config StarTopologySimulation]

network = StarTopology

# Node configuration

**.node[*].numApps = 1

**.node[*].app[0].typename = “UdpBasicApp”

**.node[*].app[0].destAddress = “hub”

**.node[*].app[0].startTime = uniform(1s, 2s)

**.node[*].app[0].sendInterval = uniform(1s, 3s)

**.node[*].app[0].packetLength = 512B

# Hub configuration

**.hub.numApps = 1

**.hub.app[0].typename = “UdpSink”

# Simulation time

sim-time-limit = 100s

  1. Add Traffic Flows
  • Set the nodes for transmitting information to the hub.
  • Optionally, we can create the hub transmit the information to other nodes for replicating a routing function.
  1. Run and Visualize the Simulation
  • Run the Simulation: We need to execute the simulation using OMNeT++.
  • Monitor Behavior:
    • Data floods among the nodes and the hub.
    • Observe the performance indicators like latency and packet delivery ratio.
  1. Analyze Results

Metrics to Evaluate:

  1. Packet Delivery Ratio (PDR):
    • Estimate the rate of packets that are effectively inherited using hub.
  2. Latency:
    • Assess the delay among transmitting and inheriting the packets.
  3. Throughput:
    • Examine the bandwidth utilised with the network.

Visualization:

  • Envision traffic models and node communications to utilise OMNeT++’s tools for visualization.
  1. Enhance the Project

Step 9.1: Wireless Star Topology

  • Replicate a wireless star topology including an access point like hub with the help of INET’s wireless components.

Step 9.2: Add Failure Scenarios

  • Replicate the hub failure for monitoring their influence over the network.
  • Measure the redundancy methods or backup hub approaches.

Step 9.3: Add Dynamic Behavior

  • Integrate mobility utilising the mobility models of INET to peripheral nodes.
  • Replicate the dynamic traffic models.
  1. Example Output
  • Before Enhancements:
    • Nodes transmit the packets to the hub, and performance indicators such as throughput and latency are stable.
  • After Enhancements:
    • To integrate the mobility or failure scenarios that impacts packet delivery and performance parameters after improvements.

We had indicated the complete simulation process for replicating and analysing the Star Topology projects via OMNeT++ simulation tool. If you know more about how to set specific aspects, integrate wireless communication, or replicate advanced scenarios like hub failure or redundancy, we will give assistance for you.