How to Start Network Context Aware Systems Projects Using NS2

To start a Network Context-Aware Systems project in NS2 that encompasses to model and replicate the networks, which actively adjust according to the environmental or operational contexts. These systems are typically utilised within IoT, smart cities, and adaptive mobile networks in which network adapts their behavior depends on the metrics like user mobility, network load, or device capabilities.

Below are sequential steps to get started:

Steps to Start Network Context Aware Systems Projects in NS2

1. Understand Network Context-Aware Systems

• Key Features:
  • Context awareness: The capability to detect and response to environmental changes like user mobility, signal strength.
  • Dynamic adaptation: To change the behavior of network such as routing, resource allocation within response to context.
• Applications:
  • Mobile networks (e.g., seamless handover in 5G).
  • IoT (e.g., resource-constrained device networks).
  • Smart cities (e.g., traffic management systems).

2. Prepare Your Environment

• Install NS2:
  • We can set up NS2 on a Linux-based system:

sudo apt-get update

sudo apt-get install ns2 nam

• • Confirm the installation by executing the sample scripts.
• Familiarize Yourself with NS2 Basics:
  • Focus on TCL scripting for simulation situations.
  • Observe how to change C++ code for further development of protocol.

3. Define the Project Objectives

• Choose a Context-Aware Scenario:
  • Traffic-aware routing (e.g., load balancing in congested networks).
  • Energy-aware IoT communication.
  • Mobility-based adaptation (e.g., handovers in mobile networks).
• Key Metrics:
  • Energy consumption.
  • Packet delivery ratio.
  • Quality of Service (QoS) parameters such as throughput and delay.
  • Adaptation latency.

4. Design the Network Topology

• Nodes:
  • Specify the devices, base stations, or sensors in the nodes.
• Links:
  • Make use of wireless links for dynamic and mobile scenarios.
• Traffic:
  • Describe the realistic traffic models according to the context-aware use case.

5. Write the TCL Script

• Make a network simulation including context-awareness logic in tcl script.
• Example: Mobility-Based Adaptive Routing

# Create a simulator

set ns [new Simulator]

# Trace and animation files

set tracefile [open trace.tr w]

set namfile [open output.nam w]

$ns trace-all $tracefile

$ns namtrace-all $namfile

# Create nodes

set num_nodes 10

for {set i 0} {$i < $num_nodes} {incr i} {

set node($i) [$ns node]

$node($i) set X_ [expr $i * 20]

$node($i) set Y_ [expr $i * 10]

$node($i) set Z_ 0

}

# Configure wireless links

$ns node-config -adhocRouting DSR -llType LL -macType Mac/802_11 \

-ifqType Queue/DropTail/PriQueue -ifqLen 50 \

-antType Antenna/OmniAntenna -propType Propagation/TwoRayGround

# Mobility model

for {set i 0} {$i < $num_nodes} {incr i} {

$node($i) setdest [expr $i * 30] [expr $i * 15] 5.0

}

# Define traffic sources

set udp [new Agent/UDP]

set null [new Agent/Null]

$ns attach-agent $node(0) $udp

$ns attach-agent $node(9) $null

$ns connect $udp $null

set cbr [new Application/Traffic/CBR]

$cbr set packetSize_ 512

$cbr set rate_ 1Mb

$cbr attach-agent $udp

# Schedule events

$ns at 1.0 “$cbr start”

$ns at 10.0 “finish”

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exit 0

}

# Run simulation

$ns run

6. Implement Context-Aware Behavior

• Dynamic Context Sensing:
  • Replicate the context changes to utilise mobility models or channel quality metrics of NS2.
• Example Contexts:
  • Signal Strength: Activate the route changes or handovers.
  • Mobility: Modify the routing or resource allocation actively.
  • Traffic Load: Stabilize the traffic for preventing congestion.

7. Extend NS2 for Advanced Features

• Fine-tune NS2’s C++ code for integrating custom context-aware logic.
• Example: Custom Routing Protocol
  • Prolong the AODV or DSR protocols to take decisions for routing depends on the signal strength or mobility.
• Add Custom Metrics:
  • Observe the custom parameters like adaptation latency or energy consumption.

8. Run and Debug the Simulation

• Run the TCL script in NS2:

ns your_script.tcl

• Debug and examine the simulation using trace file (trace.tr) and animation file (output.nam).

9. Analyze Results

• Trace File Analysis:
  • Make use of AWK, Python, or MATLAB tools for examining the trace files.
  • Measure the performance parameters like:
    • Adaptation efficiency.
    • Packet delivery ratio.
    • Latency and throughput.
• Visualization:
  • For graphical representation, we will need to apply Gnuplot, Matplotlib, or MATLAB tools.

10. Enhance the System

• Mobility Models:
  • Replicate the realistic mobility to utilise Random Waypoint or Gauss-Markov designs.
• QoS Mechanisms:
  • Execute the priority queues for handling diverse traffic types.
• Energy-Awareness:
  • Replicate power-efficient protocols for IoT devices.

11. Research Topics for Context-Aware Systems

• Mobility-Aware Routing:
  • Enhance the mobility routing protocols for VANETs, MANETs are mobile networks.
• Traffic-Aware Load Balancing:
  • Execute the mechanisms for stabilizing the network load rely on real-time traffic situations.
• Energy-Aware IoT Systems:
  • Enhance the power utilization for resource-constrained devices.
• Security in Context-Aware Networks:
  • Focus on adaptive protocols to identify and moderate the network attacks.

12. Example Use Cases

• Smart Cities:
  • Replicate the smart cities with traffic light systems, which adjust to density of vehicle.
• IoT Networks:
  • Mimic sensor nodes, which adapt the data transmission according to the battery life.
• Mobile Networks:
  • Replicate the seamless handover among the base stations for mobile users.

Through NS2, we were able to conduct a comprehensive simulation process, addressing requirements of Network Context Aware Systems that were replicated and examined the performance. More insights relevant to this topic will be made available.