How to Implement 3D Wireless Sensor Modeling in NS2

To execute the 3D wireless sensor modeling within NS2 (Network Simulator 2) which has contain extending the simulation environment to support communication, three-dimensional positioning, and mobility for sensor nodes. By default, the simulation NS2 works in a two-dimensional space, however with some modifications, we can expand it to manage the three-dimensional situations that is helpful for applications like underwater sensor networks, drone-based sensor networks, or sensor networks deployed in difficult 3D environments such as buildings or mountains. Given below is a simplified procedure to implement it in NS2:

Step-by-Step Guide to Implement 3D Wireless Sensor Modeling in NS2

  1. Understand the Requirements of 3D Modeling

In a 3D wireless sensor network (WSN), below elements are want to be deliberated:

  • Node Positioning in 3D: These nodes should be able to move and communicate in the 3D space (x, y, z coordinates).
  • Communication Range: The communication range among the nodes should be estimated according to 3D distances.
  • Mobility Models: This nodes can move in all three dimensions (x, y, and z) including 3D mobility patterns.
  1. Modify Node Positioning for 3D Support

In the simulation NS2, the nodes have 2D positions (x, y), however we can expand it to contain a third dimension (z). It needs to change the MobileNode class and its connected methods to support 3D coordinates.

Modify the Node Position in C++:

The MobileNode class, described in mobilenode.cc and mobilenode.h, in which the node positioning is managed. We can expand the class to store the z-coordinate and modify the positioning methods.

Example C++ Code to Extend MobileNode to 3D:

class MobileNode : public Node {

public:

MobileNode();

 

// Get and set position in 3D (x, y, z)

void get_position(double &x, double &y, double &z);

void set_position(double x, double y, double z);

protected:

double z_;  // Add z-coordinate to store the height in 3D space

};

// Constructor to initialize 3D coordinates

MobileNode::MobileNode() : Node(), z_(0.0) {

}

// Get the current position (x, y, z)

void MobileNode::get_position(double &x, double &y, double &z) {

x = X_;

y = Y_;

z = z_;

}

// Set the position in 3D space

void MobileNode::set_position(double x, double y, double z) {

X_ = x;

Y_ = y;

z_ = z;

}

By adjusting the MobileNode class that nodes have a third dimension (z_) and can store their 3D coordinates.

  1. Modify Mobility Models for 3D Space

In the simulation NS2, the mobility models are used to move nodes over the network. We can alter the current mobility models or make a new ones to permit movement in 3D space (x, y, and z). For instance, Random Waypoint or Random Walk mobility models can be expanded to permit movement in the z-direction.

Example 3D Random Waypoint Mobility Model:

# Define the node’s initial position in 3D space

$node set X_ 10.0

$node set Y_ 20.0

$node set Z_ 30.0

# Set a new 3D destination (x, y, z) with a speed

$node setdest 100.0 200.0 50.0 5.0  ;# Move to (100, 200, 50) at 5 m/s

We can describe mobility models in a Tcl script which permits the nodes to move in a 3D area.

  1. Adjust the Communication Range for 3D Distance

In the simulation NS2, communication among the nodes is depends on their distance, estimated using the 2D Euclidean distance formula. For 3D support, the distance calculation should be expanded to manage the 3D space.

Modify the Distance Calculation:

Extend the distance formula in the packet transmission code to deliberate the z-coordinate.

Example C++ Code to Calculate 3D Distance:

double MobileNode::distanceTo(MobileNode *other) {

double dx = X_ – other->X_;

double dy = Y_ – other->Y_;

double dz = z_ – other->z_;

return sqrt(dx * dx + dy * dy + dz * dz);  // 3D Euclidean distance

}

Now, nodes will verify their communication range in 3D space, with this modified distance calculation, make sure that both horizontal and vertical distances are deliberated.

  1. Handle Packet Transmission in 3D

In NS2, while a packet is transmitted, the simulation verifies if the receiving node is in the range depends on the distance among the nodes. Because we now have 3D positions, the distance check should be completed using the 3D distance formula we executed earlier.

Modify the Transmission Range Check:

In the transmission model such as TwoRayGround or FreeSpace, we can use the new 3D distance formula to ascertain if a node can be received the packet.

if (node1->distanceTo(node2) <= transmission_range) {

// Node2 is within the transmission range, so it can receive the packet

sendPacket();

}

  1. Update Routing Protocols for 3D Network

Routing protocols such as AODV, DSR, etc. that can be worked within a 3D environment without modification since they depends on the logical paths instead of physical positioning. But, if we require to enhance the routing for 3D networks, we may want to alter the protocol to get the z-coordinate into account while estimating the routes or hop distances.

For specimen, we can alter the AODV protocol to select the routes, which have lower overall 3D distances among the nodes.

  1. Simulate 3D Wireless Sensor Networks in a Tcl Script

When the C++ modifications are done, we can configure a 3D wireless sensor network within a Tcl simulation script. Describe a sensor nodes with 3D coordinates then run the simulation.

Example Tcl Script for 3D WSN Simulation:

# Create a simulator instance

set ns [new Simulator]

# Create sensor nodes

set node1 [$ns node]

set node2 [$ns node]

set node3 [$ns node]

# Set initial positions in 3D space (x, y, z)

$node1 set X_ 10.0

$node1 set Y_ 20.0

$node1 set Z_ 30.0

$node2 set X_ 50.0

$node2 set Y_ 60.0

$node2 set Z_ 70.0

$node3 set X_ 100.0

$node3 set Y_ 110.0

$node3 set Z_ 120.0

# Define mobility for 3D space (if necessary)

$node1 setdest 200.0 150.0 50.0 3.0  ;# Move to a new 3D location at 3 m/s

# Define traffic and routing (AODV, DSR, etc.)

$ns rtproto AODV

# Define communication between nodes (e.g., UDP traffic)

set udp1 [new Agent/UDP]

set udp2 [new Agent/UDP]

set null [new Agent/Null]

$ns attach-agent $node1 $udp1

$ns attach-agent $node2 $udp2

$ns attach-agent $node3 $null

$ns connect $udp1 $null

$ns connect $udp2 $null

# Define a CBR traffic generator

set cbr [new Application/Traffic/CBR]

$cbr set packetSize_ 512

$cbr set interval_ 0.1

$cbr attach-agent $udp1

# Start the traffic

$ns at 1.0 “$cbr start”

# Run the simulation

$ns run

  1. Analyse the Simulation

We can use NS2’s trace files to assess the performance of the 3D wireless sensor network, after running the simulation. Important metrics comprise:

  • Packet Delivery Ratio: Estimate the percentage of packets effectively delivered to the end.
  • Throughput: Examine the data throughput over the network.
  • End-to-End Delay: Verify how much time it takes for packets to travel among the nodes in 3D space.

As illustrated above, we execute the implementation steps that implement and analyse the 3D Wireless Sensor Modeling in the NS2. More specific details on this topic will be shared later, if needed.

If you’re looking to implement 3D Wireless Sensor Modeling in the NS2 tool, feel free to contact us! We’re here to provide you with a concise explanation and ensure timely delivery. Our team specializes in underwater sensor networks, drone-based sensor networks, and can customize solutions to meet your specific requirements.