How to Implement Cellular Topology in NS2

 

To implement the Cellular Topology in Network Simulator 2 (ns2), this topology is network structure in which the network area is break down into cells, all are served by a base station or access point. In every cell, mobile nodes (or clients) interact with the base station which is interconnected to direct traffic amongst them. It is typical in cellular networks like 4G and 5G systems.

In order to implement it, we have to set up base stations and mobile nodes for every cell and then simulate communication amongst mobile nodes inside and over cells through the base stations. We specialize in Cellular Topology projects using the NS2 tool, and if you’re looking for personalized research, feel free to reach out to ns2project.com for customized support. In this manual, we delivered the entire instructions of cellular topology’s implementation in ns2:

Steps to Implement Cellular Topology in NS2:

  1. Set Up the Cellular Network Topology:
    • Design base stations (fixed nodes) and mobile nodes (clients) in each cell.
    • Generate duplex links amongst mobile nodes and their corresponding base stations.
    • Link base stations to one another, enabling inter-cell communication.
  2. Simulate Traffic Flow:
    • Produce traffic amongst mobile nodes inside the same cell and across various cells by routing it through the base stations.

Example of Cellular Topology Implementation in NS2:

In this simulation, we will configure a simple cellular topology with two cells, each with one base station and three mobile nodes. Traffic flows amongst mobile nodes in the same cell and amidst mobile nodes in several cells via the base stations.

# Create a new simulator

set ns [new Simulator]

# Open trace file for output

set tracefile [open out.tr w]

$ns trace-all $tracefile

# Define base station for Cell 1

set base_station1 [$ns node]    ;# Base station for Cell 1

# Define mobile nodes for Cell 1

set mobile1_1 [$ns node]        ;# Mobile node 1 in Cell 1

set mobile1_2 [$ns node]        ;# Mobile node 2 in Cell 1

set mobile1_3 [$ns node]        ;# Mobile node 3 in Cell 1

# Create duplex links between mobile nodes and base station in Cell 1

$ns duplex-link $mobile1_1 $base_station1 1Mb 10ms DropTail  ;# Link between mobile1_1 and base station

$ns duplex-link $mobile1_2 $base_station1 1Mb 10ms DropTail  ;# Link between mobile1_2 and base station

$ns duplex-link $mobile1_3 $base_station1 1Mb 10ms DropTail  ;# Link between mobile1_3 and base station

# Define base station for Cell 2

set base_station2 [$ns node]    ;# Base station for Cell 2

# Define mobile nodes for Cell 2

set mobile2_1 [$ns node]        ;# Mobile node 1 in Cell 2

set mobile2_2 [$ns node]        ;# Mobile node 2 in Cell 2

set mobile2_3 [$ns node]        ;# Mobile node 3 in Cell 2

# Create duplex links between mobile nodes and base station in Cell 2

$ns duplex-link $mobile2_1 $base_station2 1Mb 10ms DropTail  ;# Link between mobile2_1 and base station

$ns duplex-link $mobile2_2 $base_station2 1Mb 10ms DropTail  ;# Link between mobile2_2 and base station

$ns duplex-link $mobile2_3 $base_station2 1Mb 10ms DropTail  ;# Link between mobile2_3 and base station

# Create a duplex link between base station 1 and base station 2 to allow inter-cell communication

$ns duplex-link $base_station1 $base_station2 2Mb 10ms DropTail  ;# Link between base station 1 and base station 2

# Define TCP agents for communication between mobile nodes

# Traffic from mobile1_1 (Cell 1) to mobile1_3 (within Cell 1)

set tcp0 [new Agent/TCP]

set sink0 [new Agent/TCPSink]

$ns attach-agent $mobile1_1 $tcp0

$ns attach-agent $mobile1_3 $sink0

$ns connect $tcp0 $sink0

# Simulate FTP traffic from mobile1_1 to mobile1_3 (within Cell 1)

set ftp0 [new Application/FTP]

$ftp0 attach-agent $tcp0

$ns at 1.0 “$ftp0 start”   ;# Start traffic at 1 second

# Traffic from mobile2_2 (Cell 2) to mobile1_2 (across cells via base stations)

set tcp1 [new Agent/TCP]

set sink1 [new Agent/TCPSink]

$ns attach-agent $mobile2_2 $tcp1

$ns attach-agent $mobile1_2 $sink1

$ns connect $tcp1 $sink1

# Simulate FTP traffic from mobile2_2 (Cell 2) to mobile1_2 (Cell 1)

set ftp1 [new Application/FTP]

$ftp1 attach-agent $tcp1

$ns at 2.0 “$ftp1 start”   ;# Start traffic at 2 seconds

# End the simulation after 10 seconds

$ns at 10.0 “finish”

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

# Run the simulation

$ns run

Explanation of the Script:

  1. Cell 1:
    • base_station1: This is the base station serving Cell 1.
    • mobile1_1, mobile1_2, and mobile1_3: These are the mobile nodes in Cell 1.
    • Duplex links are designed amongst each mobile node and the base station in Cell 1.
  2. Cell 2:
    • base_station2: This is the base station serving Cell 2.
    • mobile2_1, mobile2_2, and mobile2_3: These are the mobile nodes in Cell 2.
    • Duplex links are set up between each mobile node and the base station in Cell 2.
  3. Inter-cell Communication:
    • A duplex link is developed between base_station1 and base_station2 to permit communication between mobile nodes in numerous cells.
  4. Traffic Simulation:
    • TCP agents simulate communication between nodes.
    • Use the FTP (File Transfer Protocol) to generate traffic between the mobile nodes.
    • Traffic flows from mobile1_1 to mobile1_3 inside Cell 1, and from mobile2_2 to mobile1_2 across cells through the base stations.
  5. Simulation Duration:
    • The simulation runs for 10 seconds, permitting traffic to flow amongst mobile nodes in the same and different cells.

Post-Simulation Analysis:

  1. Trace File Analysis:
    • Monitor how packets are moved amongst mobile nodes inside the same cell and over cells via base stations by opening the trace file (out.tr). Compute metrics like packet delivery, delay and throughput.
  2. NAM Visualization:
    • NAM (Network Animator) is used to visualize the cellular topology. You will see mobile nodes linked to their corresponding base stations, and how traffic flows amongst nodes in the same cell and across cells.
  3. Performance Metrics:
    • Compute network performance metrics like delay, throughput, and packet loss to measure how well the cellular topology manages traffic.

Enhancing the Simulation:

  1. Adding More Cells:
    • Include more base stations and mobile nodes to replicate a larger cellular network with several cells.
  2. Simulating Traffic in Both Directions:
    • Configure additional traffic in both directions (e.g., from mobile1_3 to mobile1_1 or from mobile1_2 to mobile2_2) to simulate bidirectional communication.
  3. Changing Traffic Type:
    • Exchange the TCP with UDP or use CBR (Constant Bit Rate) instead of FTP to simulate different types of traffic and assess how the network functions.
  4. Simulating Mobility:
    • You can execute mobility models where mobile nodes travel among various cells, simulating handovers amidst base stations.
  5. Varying Link Parameters:
    • Investigate with several link parameters includes bandwidth, delay, and queue type (such as DropTail or RED) to learn how the network performance vary in different conditions.

We offered the brief explanation and processing approach regarding the cellular topology and their implementation by using their vital mechanisms in ns2 tool. Also, you can evaluate it and enhance by following the given techniques. If you need additional information of cellular networks, we can offer it. With our expertise, you can expect exceptional implementation outcomes. Additionally, we offer complete comparison analysis results and focus on mobile nodes.