JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD MCA 2022 AD-HOC AND SENSOR NETWORKS Previous Question Paper (September/October - 2022 - R20)

Mobile Ad-hoc Networks (MANETs) are infrastructure-less networks that support dynamic topologies, making them ideal for scenarios where centralized communication is unavailable. Key applications include:

• Military Tactical Operations: Used for battlefield communication, enabling soldiers, vehicles, and command centers to maintain connectivity without pre-existing infrastructure.
• Emergency and Disaster Relief: Essential in search-and-rescue operations following earthquakes, floods, or fires where traditional cellular or wired networks are destroyed.
• Collaborative Computing: Facilitates ad-hoc meetings, conferences, or classroom environments where users need to share files and resources locally without an access point.
• Sensor Networks: Used in environmental monitoring or industrial settings where mobile sensors gather and relay data to a sink node.
• Personal Area Networks (PAN): Enables communication between personal devices like smartphones, tablets, and wearables in close proximity.

The decentralized and dynamic nature of MANETs introduces several technical challenges that complicate network performance:

• Dynamic Topology: Nodes move independently, causing frequent link breakages and requiring constant route updates, which increases control overhead.
• Limited Bandwidth and Resources: Wireless links have lower capacity than wired networks, and nodes often have limited battery power and processing capability, necessitating energy-efficient protocols.
• Security Vulnerabilities: The absence of a central authority makes the network susceptible to eavesdropping, spoofing, and denial-of-service (DoS) attacks.
• Hidden and Exposed Terminal Problems: Wireless medium contention leads to packet collisions, requiring sophisticated medium access control (MAC) mechanisms.
• Scalability: Maintaining performance as the number of nodes increases is difficult due to the broadcast nature of the wireless medium and the overhead of routing protocols.
• Quality of Service (QoS): Providing guaranteed latency, jitter, and throughput is challenging in a highly mobile environment where the path between source and destination is constantly changing.