JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD MCA 2022 INTERNET OF THINGS Previous Question Paper (March/April - 2022 - R15)

The Internet of Things (IoT) is a network of physical objects or 'things' embedded with sensors, software, and other technologies for the purpose of connecting and exchanging data with other devices and systems over the internet. These objects range from ordinary household items to sophisticated industrial tools.

Key characteristics of IoT include:

• Connectivity: Enables network accessibility and compatibility, allowing devices to communicate seamlessly.
• Intelligence: IoT systems use data analytics and machine learning to extract meaningful information from raw sensor data.
• Dynamic and Self-Adapting: Devices can dynamically adapt to changing contexts and environments, such as changing states or locations.
• Scalability: The ability to support a massive number of devices and handle the resulting data traffic.
• Sensing: The capability to gather data from the physical environment using various sensors.
• Security: Protecting the integrity of data and the privacy of users is critical due to the distributed nature of the network.

The IoT protocol stack is organized into layers to manage communication between devices, gateways, and cloud platforms. The primary layers and their associated protocols are:

• Application Layer: Handles data presentation and user interaction. Key protocols include MQTT (Message Queuing Telemetry Transport) for lightweight messaging, CoAP (Constrained Application Protocol) for low-power devices, and HTTP/REST for web-based services.
• Transport Layer: Ensures end-to-end communication. TCP is used for reliable connection-oriented communication, while UDP is preferred for real-time, low-latency applications where packet loss is acceptable.
• Network/Internet Layer: Manages routing and addressing. IPv6 is essential for providing unique addresses to billions of IoT devices, often utilizing 6LoWPAN to compress IPv6 packets for transmission over IEEE 802.15.4 networks.
• Link/Physical Layer: Defines the hardware and transmission medium. Common protocols include IEEE 802.15.4 (ZigBee/Thread), Bluetooth Low Energy (BLE), Wi-Fi, and LoRaWAN for long-range, low-power wide-area network communication.