Simulation LEACH Protocol with ZigBee Standard in OPNET

Simulation LEACH Protocol with ZigBee Standard Using OPNET

In this section, we have prepared the simulation of the LEACH protocol with the ZigBee standard in Wireless Sensor Networks (WSN) using the OPNET Riverbed Modeler (17.5), along with an educational video demonstrating the simulation process of the project in two scenarios. In the following, we introduce the LEACH protocol, the ZigBee standard, and wireless sensor networks, and provide images of the simulation project outputs along with a portion of the educational video for this project.

LEACH and  ZigBee on WSN Networks

LEACH Protocol

The LEACH (Low-Energy Adaptive Clustering Hierarchy) protocol is a theoretically significant routing strategy in Wireless Sensor Networks (WSNs), designed to optimize energy consumption and extend network longevity through a hierarchical, cluster-based approach. In its theoretical framework, LEACH divides network operation into rounds, each comprising a setup phase, where nodes probabilistically self-select as cluster heads based on a threshold formula incorporating factors like the desired cluster head percentage and past selection history, and a steady-state phase, where cluster heads aggregate data from member nodes and transmit it to the base station. This probabilistic selection, rooted in a distributed algorithm, ensures energy load balancing by rotating the energy-intensive cluster head role across nodes, while the use of TDMA scheduling within clusters minimizes intra-cluster collisions and idle energy waste.

Theoretically, LEACH assumes a homogeneous node distribution and sufficient initial energy, enabling it to reduce redundant transmissions via data aggregation, though it simplifies real-world complexities like varying node distances to the base station or non-uniform energy depletion. Its decentralized nature eliminates the need for global coordination, enhancing scalability, but its single-hop transmission model and lack of adaptive energy weighting highlight areas where theoretical refinements, such as multi-hop extensions or energy-aware variants, can further align it with practical deployments. Thus, LEACH provides a foundational theoretical model for energy-efficient WSN routing, balancing simplicity with robust performance in constrained environments. The LEACH routing protocol is a structured routing protocol that distributes loads across the network. In the LEACH protocol, nodes organize themselves into local clusters, with one node in each cluster acting as the cluster head.

ZigBee Standard

The ZigBee standard, theoretically grounded in the IEEE 802.15.4 framework, represents a lightweight, energy-efficient communication protocol optimized for low-data-rate, low-power Wireless Sensor Networks (WSNs) and IoT ecosystems. Operating primarily in the 2.4 GHz ISM band, ZigBee constructs a layered architecture—spanning physical, MAC, network, and application layers—that facilitates short-range, secure, and scalable interactions among devices categorized as coordinators, routers, and end devices. In theory, its design prioritizes minimal energy expenditure, enabling end devices to conserve power through prolonged sleep states, while its mesh topology leverages multi-hop routing to extend network reach and resilience, supporting up to 65,000 nodes in an idealized scenario. The protocol’s 250 kbps data rate and 128-bit AES encryption cater to intermittent, secure transmissions of small payloads, such as sensor data, though its bandwidth constraints and potential interference in the unlicensed spectrum highlight trade-offs in high-density environments.

ZigBee’s application profiles theoretically ensure interoperability across diverse use cases, from smart grids to healthcare, while its synergy with routing protocols like LEACH underscores its role in optimizing energy-aware WSNs. Thus, ZigBee offers a robust theoretical model for decentralized, low-resource networking, balancing efficiency, scalability, and simplicity in constrained systems. The ZigBee standard operates at the application layer and media access control layer, providing a smart network used for communication protocols. It is employed in high-level applications and low data rate transmissions. Additionally, the ZigBee protocol is used in personal area networks (PANs) and low-power, small-scale networks, with its technology based on the IEEE 802.15.4 standard.

Wireless Sensor Network (WSN)

A wireless sensor network is a type of wireless communication network where numerous small sensor nodes are deployed in large numbers for a specific mission. Today, WSNs have widespread applications in areas such as agriculture, traffic monitoring, earthquake detection, sound detection, military purposes, battlefield surveillance, health monitoring, and more. Each node in this network can detect physical, technical, or chemical changes and send the data to a central station for evaluation by the user.

Resource Constraints in Wireless Sensor Networks

• Memory limitations

• Processing power

• Battery power

Node failure in WSNs often occurs due to battery depletion, and energy efficiency is a critical concern in wireless sensor networks. Therefore, implementing energy-efficient programs and algorithms on these nodes is of great importance.

Key Challenge in WSN Computer Networks

The most significant issue in WSNs is that the nodes are organized as a network, and these wireless sensor networks are used for environmental monitoring. The accuracy of the collected data is highly important and depends on the nodes' capacity to perform their tasks, making energy consumption a critical factor in this context.

Steps for Simulating the LEACH Protocol with the ZigBee Standard

To create a new project in the OPNET software, we must go to the "File" menu, select "New," and then choose "Project" from the dropdown menu, followed by clicking "OK." Then, we will configure the settings step-by-step as follows:

1.       In the "Enter Name" section, enter the project name as "Leach2."

2.       In the "Initial Topology" section, select "Create empty scenario."

3.       In the "Network Scale" section, choose "Campus."

4.       In the "Specify Size" section, select a size of 10x10 kilometers.

5.       In the "Select Technologies" section, choose the ZigBee standard.

6.       Finally, click "Finish" to enter the OPNET workspace.

7.       Create the "WSN-Leach" scenario.

8.       Create the "WSN-Normal" scenario.

9.       Run the simulation and observe the resulting charts.

Additional Explanation:

The simulation of the LEACH protocol combined with the ZigBee standard in OPNET provides a practical approach to studying energy-efficient routing in wireless sensor networks. The LEACH protocol’s cluster-based structure helps prolong network lifespan by rotating the role of the cluster head among nodes, thus balancing energy consumption. Integrating this with the ZigBee standard, which is designed for low-power, low-data-rate applications, enhances the efficiency of WSNs, especially in scenarios requiring long-term operation with minimal maintenance.

The use of OPNET as a simulation tool allows for detailed modeling of network behavior under various conditions. The two scenarios ("WSN-Leach" and "WSN-Normal") likely compare the performance of the LEACH protocol against a baseline (non-LEACH) setup, enabling users to analyze metrics such as energy consumption, node lifetime, and data delivery rates. The educational video and output images further assist in visualizing how the protocol operates within the ZigBee framework, offering insights into node clustering, data transmission, and network scalability.

The resource constraints highlighted—memory, processing power, and battery life—are central to WSN design. For instance, battery depletion directly affects network reliability, as nodes that run out of power can disrupt data collection and transmission. The emphasis on energy efficiency in both LEACH and ZigBee addresses this by minimizing unnecessary energy expenditure, making them suitable for real-world applications like environmental monitoring or disaster detection, where replacing batteries in remote sensor nodes is impractical.

In the simulation steps, choosing a 10x10 km campus-scale network reflects a realistic deployment area for WSNs, such as a large agricultural field or a university campus. The ZigBee standard’s compatibility with IEEE 802.15.4 ensures that the simulation adheres to widely accepted communication protocols, making the results applicable to real hardware implementations. The charts generated at the end of the simulation process likely include key performance indicators (KPIs) like energy usage per node, packet delivery ratio, or network throughput, providing a quantitative basis for evaluating the LEACH-ZigBee integration.

Note: If you have installed and activated OPNET 17.5 with a valid license, buy this project.