How to Implement Integrated Access Backhaul Networks in ns2

To implement the Integrated Access and Backhaul (IAB) networks within NS2 has needs to contain simulating a network architecture in which the similar infrastructure is used for both access and backhaul links. It is generally seen in next-generation wireless networks such as 5G, in which the base stations deliver both access to end users and backhaul connectivity to the core network. The following is a step-by-step approach to executing an Integrated Access and Backhaul (IAB) network in NS2:

Step-by-Step Implementation:

  1. Understand IAB Network Components:
  • IAB Node (Base Station): Performs as both an access point for end users and a relay for backhaul traffic.
  • Access Nodes (User Equipment): These devices that connect to the IAB node for the network access.
  • Backhaul Links: Connect the IAB nodes to the core network or various IAB nodes, forming a multi-hop backhaul.
  1. Set Up the NS2 Environment:
  • Make sure NS2 is installed on the computer.
  • We can get to know the writing TCL scripts, as NS2 simulations are controlled through the TCL.
  1. Define the Network Topology:
  • Make a nodes signifying user devices, IAB nodes which performs as both access points and relays, and the core network.

# Define the simulator

set ns [new Simulator]

# Create a trace file for analysis

set tracefile [open out.tr w]

$ns trace-all $tracefile

# Create a NAM file for animation

set namfile [open out.nam w]

$ns namtrace-all-wireless $namfile 10

# Set up the network parameters

set opt(chan)   Channel/WirelessChannel      ;# Channel type

set opt(prop)   Propagation/TwoRayGround     ;# Radio-propagation model

set opt(netif)  Phy/WirelessPhy              ;# Network interface type

set opt(mac)    Mac/802_11                   ;# MAC type

set opt(ifq)    Queue/DropTail/PriQueue      ;# Interface queue type

set opt(ll)     LL                           ;# Link layer type

set opt(ant)    Antenna/OmniAntenna          ;# Antenna model

set opt(ifqlen) 50                           ;# Max packet in ifq

set opt(x)      1000                         ;# X dimension of the topography

set opt(y)      1000                         ;# Y dimension of the topography

set opt(adhocRouting) AODV                   ;# Ad hoc routing protocol

# Create a topography object

create-god 50

# Configure the nodes (e.g., users, IAB nodes, core network)

$ns node-config -adhocRouting $opt(adhocRouting) \

-llType $opt(ll) \

-macType $opt(mac) \

-ifqType $opt(ifq) \

-ifqLen $opt(ifqlen) \

-antType $opt(ant) \

-propType $opt(prop) \

-phyType $opt(netif) \

-channelType $opt(chan) \

-topoInstance $topo \

-agentTrace ON \

-routerTrace ON \

-macTrace OFF \

-movementTrace ON

# Create nodes: Users, IAB Nodes, Core Network

set user1 [$ns node]  ;# User 1

set user2 [$ns node]  ;# User 2

set iab1 [$ns node]   ;# IAB Node 1 (access and backhaul)

set iab2 [$ns node]   ;# IAB Node 2 (backhaul relay)

set core1 [$ns node]  ;# Core Network Node

# Set initial positions for the nodes

$user1 set X_ 100.0

$user1 set Y_ 300.0

$user1 set Z_ 0.0

$user2 set X_ 200.0

$user2 set Y_ 300.0

$user2 set Z_ 0.0

$iab1 set X_ 300.0

$iab1 set Y_ 300.0

$iab1 set Z_ 0.0

$iab2 set X_ 400.0

$iab2 set Y_ 300.0

$iab2 set Z_ 0.0

$core1 set X_ 500.0

$core1 set Y_ 300.0

$core1 set Z_ 0.0

  1. Simulate Communication Between Access Nodes and IAB Nodes:
  • Configure the communication links among user devices and the IAB nodes and these links signify the access portion of the IAB network.

# Create duplex links between user devices and IAB Node 1 (access)

$ns duplex-link $user1 $iab1 10Mb 10ms DropTail

$ns duplex-link $user2 $iab1 10Mb 10ms DropTail

  1. Simulate Backhaul Communication Between IAB Nodes and Core Network:
  • Set up communication links among the IAB nodes and the core network and these links denote the backhaul portion of the IAB network.

# Create duplex links between IAB Node 1 and IAB Node 2 (backhaul)

$ns duplex-link $iab1 $iab2 100Mb 5ms DropTail

# Create duplex link between IAB Node 2 and Core Network (backhaul)

$ns duplex-link $iab2 $core1 100Mb 5ms DropTail

  1. Implement Data Transmission:
  • To replicate the transmission of data from user devices to the core network through the IAB nodes. We can use TCP/UDP agents to model these transmissions.

# User 1 sends data to the Core Network via IAB Node 1 and IAB Node 2

set tcp_user1 [new Agent/TCP]

$ns attach-agent $user1 $tcp_user1

set tcp_core1_sink [new Agent/TCPSink]

$ns attach-agent $core1 $tcp_core1_sink

$ns connect $tcp_user1 $tcp_core1_sink

# Start sending data from User 1

set app_user1 [new Application/FTP]

$app_user1 attach-agent $tcp_user1

$ns at 1.0 “$app_user1 start”

# User 2 sends data to the Core Network via IAB Node 1 and IAB Node 2

set tcp_user2 [new Agent/TCP]

$ns attach-agent $user2 $tcp_user2

# Start sending data from User 2

set app_user2 [new Application/FTP]

$app_user2 attach-agent $tcp_user2

$ns at 2.0 “$app_user2 start”

  1. Implement Traffic Aggregation at IAB Nodes:
  • IAB nodes can aggregate traffic from several users before forwarding it to the core network. This stage mimics that behaviour.

# Example procedure to aggregate traffic at IAB Node 1

proc aggregate_traffic {src1 src2 dst} {

global ns

puts “Aggregating traffic from $src1 and $src2 at IAB Node 1”

$ns at [expr $ns now + 0.1] “$src1 send packet to dst”

$ns at [expr $ns now + 0.1] “$src2 send packet to dst”

}

# Schedule traffic aggregation at IAB Node 1

$ns at 3.0 “aggregate_traffic $user1 $user2 $core1”

  1. Run the Simulation:
  • Describe when the simulation should terminate and execute it. The finish procedure will close the trace files and introduce the NAM for visualization.

# Define the finish procedure

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam out.nam &

exit 0

}

# Schedule the finish procedure at 20 seconds

$ns at 20.0 “finish”

# Run the simulation

$ns run

  1. Analyse the Results:
  • Use the trace file (out.tr) to estimate data transmission, network performance, and backhaul efficiency.
  • Open the NAM file (out.nam) to visualize the network operations and monitor the interactions among the user devices, IAB nodes, and the core network.
  1. Customize and Extend:
  • We can customize the simulation by:
    • Attaching more user devices and IAB nodes to make a larger, more difficult IAB network.
    • Executing dynamic routing algorithms to enhance the backhaul performance.
    • Mimicking various traffic patterns, like bursty or real-time traffic, to analyse the IAB network’s robustness.

Example Summary:

This sample configures the simple Integrated Access and Backhaul (IAB) network simulation in NS2, concentrating on communication among the user devices, IAB nodes, and the core network. The simulation has comprises traffic aggregation at the IAB nodes, mimicking real-world IAB network behaviour.

Advanced Considerations:

  • For more difficult scenarios, deliberate the emerging custom modules or incorporating NS2 with other tools to better mimic the furthered features of IAB networks, like dynamic resource allocation or multi-hop backhaul.
  • Expand the simulation to contain furthered characteristics such as network slicing, Quality of Service (QoS) management, or energy efficiency optimization in IAB networks.

Debugging and Optimization:

  • We can use the trace-all command to debug the simulation and estimate the packet flows.
  • Enhance the simulation by refining routing decisions, modifying link parameters, and changing network properties for better performance.

We have provided an overview about on how to execute and estimate the Integrated Access and Backhaul Network using the simplified approaches in the simulation ns2. More insights will be presented depending on your needs. ns2project.com is your reliable ally for completing your research. For the implementation of Integrated Access and Backhaul Networks in ns2, we provide top-notch project guidance tailored to your needs.