How to Start Greedy Perimeter Stateless Routing Using MATLAB

To create the Greedy Perimeter Stateless Routing (GPSR) is a routing protocol primarily used in wireless ad-hoc and sensor networks. It is considered to achieve the effective routing deprived of need to every node has handle a complete routing table. GPSR used two mechanisms: here’s a step by step followed below procedures.

Steps to Start Greedy Perimeter Stateless Routing Projects Using MATLAB

  1. Greedy Forwarding: Sending the packets for the neighbor nearby to the destination according to geographical location.
  2. Perimeter Forwarding: When greedy forwarding fails such as node cannot detect a closer neighbor, the protocol switches to perimeter mode, in which uses the perimeter of the void like as obstacles or isolated nodes to forward packets.

We create a GPSR routing project in MATLAB, you will require replicating:

  1. Network topology: Characterize the nodes’ positions in a 2D or 3D space.
  2. Greedy forwarding algorithm: Packet forwarding the replication of the closest neighbor.
  3. Perimeter forwarding algorithm: Maintain the cases in which the greedy sending fails due to the voids or isolated nodes.
  4. Simulation of communication: Validate on the packet transmission with the network.

Step-by-Step Guide to Implement GPSR in MATLAB

Step 1: Define the Network Topology

Initialize through state the positions of nodes in a 2D or 3D space. Every node in the network will have the geographic manages, and the distance among two nodes can be calculated using Euclidean distance.

Here is an sample on how you can set up the nodes in a 2D space:

% Number of nodes in the network

numNodes = 10;

% Random positions for the nodes (x, y coordinates)

positions = rand(numNodes, 2) * 100; % 100×100 area

% Plot the network topology

figure;

scatter(positions(:,1), positions(:,2), ‘filled’);

title(‘Network Topology’);

xlabel(‘X Coordinate’);

ylabel(‘Y Coordinate’);

In this example, we build 10 nodes in a 100×100 area. Every node has arbitrarily allocated the (x, y) coordinate.

Step 2: Define Euclidean Distance Calculation

We apply the Greedy Forwarding and Perimeter Forwarding; we require performing and calculating the Euclidean distance among two nodes.

% Function to compute the Euclidean distance between two nodes

function distance = euclideanDistance(node1, node2)

distance = sqrt((node1(1) – node2(1))^2 + (node1(2) – node2(2))^2);

end

Step 3: Greedy Forwarding

The Greedy forwarding operates through sending the packet to the neighbor closest for the destination. The basic techniques follow these steps:

  1. Detect the neighbor nearby the destination.
  2. Send the packet for this neighbor.

Here’s how you can apply the Greedy Forwarding function:

% Greedy forwarding function

function nextHop = greedyForwarding(positions, currentNode, destination)

minDist = inf;  % Initialize minimum distance to infinity

nextHop = -1;   % No next hop initially

% Loop through all nodes and find the closest neighbor

for i = 1:size(positions, 1)

if i ~= currentNode  % Avoid the current node itself

dist = euclideanDistance(positions(currentNode, :), positions(i, :));

if dist < minDist

minDist = dist;

nextHop = i;  % Store the closest neighbor

end

end

end

end

In this function:

  • Current Node is the start for the present node in the network.
  • Destination is the goal for a destination node.
  • The function returns the next hop such as the index of the neighbor closest to the destination.

Step 4: Perimeter Forwarding

If greedy forwarding fails because no node is closer to the destination than the present node such as the packet is in a void, Perimeter Forwarding can be used. The knowledge behind the perimeter sending is to transmit the packet around the perimeter of the void until a node is found that can forward the packet towards the destination.

We can apply the Perimeter Forwarding using a right-hand rule, that assure which the packet continues transfer along the perimeter of the void.

% Perimeter forwarding function

function nextHop = perimeterForwarding(positions, currentNode, destination)

% Assume that the perimeter forwarding starts with neighbors of currentNode

neighbors = setdiff(1:size(positions, 1), currentNode); % All nodes except currentNode

% Use a simple heuristic: pick the first neighbor in the list

% In reality, you’d implement the right-hand rule or other strategies

nextHop = neighbors(1); % Dummy assignment for simplicity

end

In a real execution, we require to calculate the edges of the “void” and apply the right-hand rule such as keep turning right at each node’s neighbor.

Step 5: Simulate GPSR Packet Forwarding

By Greedy Forwarding and Perimeter Forwarding operates in place, the next stage is to replicate the packet sending in the network.

% Function to simulate packet forwarding using GPSR

function simulateGPSR(positions, source, destination)

currentNode = source;

path = currentNode;  % Path to track the nodes visited

% Simulate packet forwarding

while currentNode ~= destination

% Perform greedy forwarding first

nextHop = greedyForwarding(positions, currentNode, destination);

% If greedy forwarding fails (e.g., the packet cannot progress)

if nextHop == -1

% Switch to perimeter forwarding

nextHop = perimeterForwarding(positions, currentNode, destination);

end

% Update the current node and add it to the path

currentNode = nextHop;

path = [path, currentNode];

end

 

% Display the path followed by the packet

disp(‘Packet path:’);

disp(path);

% Plot the nodes and the packet’s path

figure;

scatter(positions(:, 1), positions(:, 2), ‘filled’);

hold on;

plot(positions(path, 1), positions(path, 2), ‘r-‘, ‘LineWidth’, 2);

title(‘GPSR Routing Path’);

xlabel(‘X Coordinate’);

ylabel(‘Y Coordinate’);

hold off;

end

This function replicates packet forwarding from a source node to a destination node:

  • It start the attempts Greedy Forwarding.
  • If greedy forwarding fails such as no closer node is found, it switches to Perimeter Forwarding.

The packet’s path is displayed on the plot, and we can envision the routing process.

Step 6: Test the GPSR Routing

To validate your GPSR implementation, we can process the following code:

% Define random positions for the nodes

numNodes = 10;

positions = rand(numNodes, 2) * 100; % 100×100 area

% Select source and destination nodes

source = 1;  % Source node index

destination = 5;  % Destination node index

% Simulate GPSR routing

simulateGPSR(positions, source, destination);

This will replicate the packet forwarding from the source node to the destination node, view the nodes and the path the packet takes.

Step 7: Enhance and Extend the GPSR Project

  1. Handle Multiple Nodes: We can encompass through replicating GPSR by several packet transmissions and validate on how the network performs through various topologies.
  2. Implement Right-Hand Rule for Perimeter Forwarding: Apply the right-hand rule further accurately, so the packet track the perimeter of the void correctly.
  3. Obstacles and Voids: Improve the obstacles or voids in the network and validate on how the routing adjust to this environment.
  4. Energy Considerations: Encompass the project with considering the energy-efficient routing, as GPSR is typically used in sensor networks.
  5. Evaluate Performance: Calculate the routing efficiency, delivery ratio, and latency of GPSR below various environment and network sizes.

This set up will walk you through the overall implementation and evaluation of Greedy Perimeter Stateless Routing Projects using MATLAB tool by defining the network topology and visualize the results which includes example snippets. If you need any further details, we will deliver it to you.