How to Start Mobile Communication Projects Using NS2

To start a Mobile Communication project in Network Simulator 2 (NS2), we will want to replicate a network in which mobile nodes like mobile phones, vehicles, or other devices interact with each other and including the infrastructure like base stations or routers whereas it transmitting. NS2 environment is a robust simulation tool that offers a range of tools and protocols, which can be utilised for replicating mobile networks with mobile ad hoc networks (MANETs), mobile cellular networks, and vehicular networks.

Below are sequential steps to get started with Mobile Communication projects in NS2:

Steps to Start Mobile Communication Projects in NS2

  1. Install NS2

Initially, we download and install it on the system using:

  • NS2 Website: NS2
  • Adhere to installation instructions based on the OS like Linux, macOS, or Windows.

Make sure we have Tcl and OTcl installed as NS2 depends on these scripting languages.

  1. Understand Mobile Communication Concepts

Mobile communication denotes interaction within a dynamic environment in which nodes like mobile devices are transfer, causing often modification within the network topology. We can replicate the various kinds of mobile network like:

  • Mobile Ad-hoc Networks (MANETs): Mobile nodes networks, which interact devoid of a fixed infrastructure.
  • Mobile Cellular Networks: In cellular network, mobile devices interconnecting with base stations (cell towers).
  • Vehicular Networks: Networks in which vehicles interact with each other or communicate with infrastructure like roadside units.

Following is a crucial mobile communication features:

  • Mobility models: Describe how nodes transfer.
  • Routing protocols: Handle the data delivery within dynamic networks like AODV, DSR.
  • Channel models: It denotes the radio transmission and reception conditions.
  1. Create a Basic Mobile Communication Topology

We will want to make nodes which are denoting mobile devices and launch its connectivity to utilise wireless links for a simple mobile communication simulation. Then, we can replicate its mobility to utilise a mobility model.

Example: Basic Mobile Ad-hoc Network (MANET) Topology

In this case, we can replicate the mobile interact with a simple MANET configuration.

# Initialize the simulator

set ns [new Simulator]

# Create nodes

set node1 [$ns node]

set node2 [$ns node]

set node3 [$ns node]

# Set up wireless links (connect nodes without any fixed infrastructure)

$ns simplex-link $node1 $node2 1Mb 10ms DropTail

$ns simplex-link $node2 $node3 1Mb 10ms DropTail

# Set mobility for nodes (using random waypoint model)

$node1 random-motion 1

$node2 random-motion 2

$node3 random-motion 3

# Set up applications (e.g., CBR for constant bit rate traffic)

set app1 [new Application/Traffic/CBR]

set app2 [new Application/Traffic/CBR]

$app1 attach-agent $node1

$app2 attach-agent $node3

$app1 set packetSize_ 512

$app1 set rate_ 1000

$app2 set packetSize_ 512

$app2 set rate_ 1000

# Run the simulation

$ns run

  • Nodes: node1, node2, node3 are mobile devices.
  • Links: Simplex links associate the nodes including 1Mb bandwidth and 10ms delay.
  • Mobility: We need to utilise the random waypoint model that is common mobility models within NS2.
  • Application: Constant Bit Rate (CBR) traffic is created among the nodes.

We can prolong this configuration by means of integrating additional nodes to modify the mobility model, or utilise other network protocols.

  1. Set Mobility Models

Nodes movement is crucial for mobile communication. NS2 environment offers numbers mobility models, which manage how the mobile nodes transfer:

  • Random Waypoint: Nodes arbitrarily transfer within the simulation area.
  • Random Direction: Nodes shift within arbitrary directions in a well-defined area.
  • Gauss-Markov: Based on the Gauss-Markov model, nodes transfer that offers additional realistic mobility.
  • Manhattan Grid: This model is frequently utilised to replicate the city-wide vehicular networks in which nodes adhere to the predefined routes.

Example: Using the Random Waypoint Mobility Model

# Set the simulation area size

set area_size 500

# Random Waypoint Mobility Model

$node1 random-motion 1

$node2 random-motion 2

$node3 random-motion 3

# Define random waypoints within the area

$node1 setdest 0 0 50  ; # Move to (0, 0) with a speed of 50 m/s

$node2 setdest 500 500 50 ; # Move to (500, 500) with a speed of 50 m/s

$node3 setdest 250 250 50 ; # Move to (250, 250) with a speed of 50 m/s

In this case, the nodes arbitrarily move within a defined area, and then we can describe the destination node and speed for every node.

  1. Set Up Routing Protocols

Routing protocols are essential for making sure that information is shared within the existence of mobility and often topology modifications in mobile networks. NS2 environment offers numerous routing protocols, which are utilised within MANETs:

  • OLSR (Optimized Link State Routing)
  • DSR (Dynamic Source Routing)
  • AODV (Ad-hoc On-demand Distance Vector)

In the simulation, we need to utilise these protocols by means of setting them.

Example: Using AODV Routing Protocol

# Create AODV routing protocol agent

set aodv1 [new AODV]

$ns node-config -routing-protocol AODV

# Attach routing protocol to each node

$node1 set protocol AODV

$node2 set protocol AODV

$node3 set protocol AODV

This instance configures the AODV routing protocol that is common reactive routing protocols for MANETs.

  1. Configure Communication Channel

Mobile communication needs a radio channel for replicating the transmission and reception of signals. In NS2, we will need to set various channel models like:

  • Wireless Channel: It is often utilised for MANETs or mobile interaction.
  • TwoRayGround Model: Mimics free-space radio broadcast including a ground reflection.

Example: Setting Up the Wireless Channel

# Set the wireless channel type

set chan [new Channel/WirelessChannel]

# Set the propagation model (e.g., TwoRayGround)

set prop [new Propagation/TwoRayGround]

# Set the antenna model (e.g., Omni Antenna)

set antenna [new Antenna/OmniAntenna]

# Set up the wireless links

$ns simplex-link $node1 $node2 1Mb 10ms DropTail

$ns simplex-link $node2 $node3 1Mb 10ms DropTail

In this case:

  • We need to make a wireless channel.
  • Make use of the TwoRayGround propagation model that replicates the physical layer of the interaction.
  • Apply OmniAntenna model in which each node contains a 360-degree antenna coverage.
  1. Set Application Layer Traffic

We want to set up the applications to make traffic among the nodes for replicating mobile communication. Below are general mobile applications:

  • Telnet for remote login.
  • FTP for file transfer.
  • Constant Bit Rate (CBR) for streaming data.

Example: Setting CBR Traffic

# Set up CBR traffic between nodes

set cbr1 [new Application/Traffic/CBR]

$cbr1 attach-agent $node1

$cbr1 set packetSize_ 512

$cbr1 set rate_ 1000  ; # 1000 bytes per second

$cbr1 set dstNode $node2

This configurations CBR traffic from node1 to node2 including amount of the packet is 512 bytes and a volume of 1000 bytes for each second.

  1. Run the Simulation

After setting up the network topology, mobility models, routing protocols, and applications then we can be executed the simulation:

ns mobile_communication.tcl

This command will be run Tcl script, and NS2 environment will be replicated the mobile network including certain metrics.

  1. Analyze the Results

When simulation is executed then NS2 makes trace files, which has in-depth records of packet transmission, routing decisions, delays, and packet losses. We need to examine these trace files for estimating the mobile communication network’s performance.

We can utilise the following tools for examining the outcomes:

  • AWK scripts: Analysing the trace files and to make statistics metrics such as throughput, delay, and packet loss.
  • NAM (Network Animator): Envisioning the simulation within graphical format.

Example of using an AWK script to analyze throughput:

awk ‘{if ($1 == “r”) print $0}’ mobile_communication.tr

This command will be executed all received packets (r) from the trace file that we may utilise for examining the packet reception.

  1. Extend the Simulation

Once you have a basic simulation set up, you can extend your project by:

  • To test with various mobility models such as Gauss-Markov, Manhattan for vehicular networks.
  • To execute and experiment various routing protocols such as OLSR, DSR.
  • Inserting Quality of Service (QoS) policies to give precedence for traffic within mobile networks.
  • To replicate the handover and cellular network dynamics if we are functioning with cellular mobile interaction.
  • Replicating network congestion or packet collision in mobile environments.

Conclusion

To start a Mobile Communication project using NS2 includes:

  1. Setting up a network topology: Make nodes and launch the wireless interaction links.
  2. Configuring mobility models: Describe how nodes transfer in the simulation.
  3. Choosing and configuring routing protocols: Choose the appropriate protocols like AODV or DSR.
  4. Simulating application traffic: Make traffic including protocols such as CBR or FTP for replicating it.
  5. Running and analyzing the simulation: Execute the simulation, make trace files, and envision outcomes to utilise NAM.

With NS2 simulation tool, we can replicate and examine the Mobile Communication Projects and estimate the various protocols performance using given comprehensive approach, we will offer advanced detailed instructions in the upcoming manual.