What is Mobile Ad Hoc Network (MANET)?

Mobile Ad Hoc Network (MANET) is a type of wireless network where mobile devices communicate with each other directly, forming a decentralized and self-organizing network. MANETs do not rely on a fixed infrastructure or central access points, allowing devices to establish and maintain network connections dynamically, often in scenarios where traditional wired or infrastructure-based networks are impractical or unavailable.

Dissecting Mobile Ad Hoc Network (MANET)

Ad hoc networks, originally rooted in military communications dating back to the mid-20th century, have evolved significantly. The term "Mobile Ad Hoc Network" gained prominence in the late 20th and early 21st century as wireless communication technologies advanced. This evolution was driven by the growing need for flexible, self-organizing networks to extend wireless communication beyond traditional infrastructure-based networks, primarily due to military requirements, disaster response needs, and scenarios where traditional network infrastructure is unavailable, impractical, or vulnerable to disruption.

How MANET works

Mobile Ad Hoc Networks (MANETs) work through a set of principles and protocols that enable mobile devices to establish and maintain communication in a decentralized and self-organizing manner. 

1. Initialization: Devices within the MANET start by initializing their network interfaces and establishing wireless connections with nearby devices. These connections can be formed directly between devices or through intermediate devices that act as relays.
2. Route Discovery: When a device (the source) wants to send data to another device (the destination) within the MANET, it needs to discover a route to reach the destination. The source device initiates a route discovery process by broadcasting a route request (RREQ) packet into the network. This RREQ packet contains the destination's address and a unique identifier for the request. Neighboring devices that receive the RREQ packet check if they are the destination or have a route to the destination in their routing tables. If not, they forward the RREQ packet to their neighbors.
3. Route Establishment: The RREQ packets continue to propagate through the network until they reach either the destination itself or a device that has a route to the destination. When the destination or an intermediate device with a valid route receives the RREQ packet, it responds by sending a route reply (RREP) packet back to the source. The RREP packet contains information about the discovered route, including the addresses of intermediate devices along the path.
4. Data Transmission: With the route established, the source device can begin transmitting data packets. These data packets are typically divided into smaller units for transmission. Each data packet is encapsulated with routing information, including the addresses of the source, destination, and intermediate devices along the route. The source device sends the data packet to the first hop (the next device along the route) by wirelessly transmitting it.
5. Multihop Relay: The first-hop device receives the data packet, processes the routing information, and forwards the packet to the next hop based on the routing information in the packet. This process of receiving, processing, and forwarding continues through multiple intermediate devices (multihop communication) until the data packet reaches the destination device.
6. Data Delivery: Once the data packet reaches the destination device, it is processed and delivered to the application or service running on the destination. The destination may also send an acknowledgment (ACK) back to the source to confirm successful data reception.
7. Dynamic Adaptation: Throughout this process, the MANET's routing protocols continuously monitor the network's status and adapt the routing tables in response to changes, such as device mobility or link quality variations.
8. End of Communication: After data exchange is complete, the devices may continue to be part of the MANET or leave the network, potentially causing routing updates if they were part of existing routes.

MANETs Features

Mobile Ad Hoc Networks (MANETs) possess several key features that distinguish them from traditional wired or infrastructure-based wireless networks. These features are integral to their operation and suitability for specific use cases. The primary key features of MANETs include:

• Decentralization: MANETs are decentralized networks where each mobile device or node participates in routing and forwarding data. There is no reliance on a central infrastructure, such as routers or access points, to manage network traffic. This decentralization allows for self-organization and adaptability.
• Dynamic Topology: MANETs have a dynamic network topology that can change rapidly due to the mobility of devices. As devices move, join, or leave the network, the network topology evolves accordingly. Adapting to these changes is a fundamental challenge in MANET design.
• Wireless Communication: MANETs primarily use wireless communication technologies, such as Wi-Fi, Bluetooth, or Zigbee, for device-to-device communication. This wireless nature makes MANETs well-suited for scenarios where wired connections are impractical or impossible.
• Ad Hoc Routing: MANETs employ specialized ad hoc routing protocols that determine how data packets should be routed between devices. These routing protocols are designed to work in dynamic and often resource-constrained environments.
• Resource Constraints: Many devices in a MANET, such as mobile phones, IoT sensors, or military radios, may have limited computational power, memory, and battery life. Adapting to these resource constraints is crucial for optimizing the network's performance and efficiency.
• Self-Configuring: MANETs are self-configuring networks, meaning that devices can autonomously establish network connections without manual configuration. This feature is especially valuable in scenarios where quick network deployment is essential.
• Multihop Communication: In MANETs, data packets are typically relayed through multiple intermediate devices (multihop communication) to reach their destination. Devices serve as both transmitters and routers, facilitating data forwarding.
• Limited Infrastructure: While MANETs do not rely on fixed infrastructure, they may still include some infrastructure nodes, such as mobile base stations or drones, to provide connectivity to devices that are out of direct radio range.
• Security Challenges: MANETs face unique security challenges due to their decentralized and dynamic nature. Securing MANETs requires addressing issues like node authentication, data encryption, and protection against malicious nodes.
• Adaptability: MANETs are highly adaptable and can be deployed in various environments, including military operations, disaster response, vehicular networks, and IoT applications. They can function in scenarios where traditional networks are impractical or susceptible to disruption.
• Flexibility: MANETs offer flexibility in network design and scalability. They can be employed in small-scale, peer-to-peer networks or large-scale networks with numerous devices.
• Application Diversity: MANETs find applications in a wide range of fields, including military communications, disaster management, intelligent transportation systems, environmental monitoring, and industrial automation.