JNTU B.Tech III DATA COMMUNICATION AND COMPUTER NETWORKS Previous Question Paper (February - 2022 - R16)

The TCP/IP model is a hierarchical protocol suite consisting of four primary layers:

1. Application Layer: This top layer enables network services for applications, such as HTTP, FTP, and SMTP. It handles high-level protocols and user interfaces.
2. Transport Layer: Responsible for end-to-end communication and error-free delivery of data. It uses protocols like TCP (connection-oriented) for reliability and UDP (connectionless) for speed.
3. Internet Layer: Handles logical addressing and routing of packets across different networks. The primary protocol is IP (Internet Protocol), which determines the best path for data transmission.
4. Network Access Layer (Host-to-Network): The lowest layer, which manages the physical transmission of data. It defines how data is physically sent through the network hardware, including framing and MAC addressing.

Light wave transmission, commonly implemented via Optical Fiber, uses light pulses to transmit information through glass or plastic strands. It operates on the principle of total internal reflection, where light signals are confined within the core of the fiber.

Key characteristics include high bandwidth, immunity to electromagnetic interference, and low signal attenuation. However, it faces several limitations:

• Attenuation: Although low, signal strength decreases over long distances, requiring optical amplifiers or repeaters.
• Dispersion: Light pulses spread out over time as they travel, which can cause inter-symbol interference and limit the maximum data rate.
• Installation Complexity: Fiber optic cables are fragile, difficult to splice, and require specialized equipment for installation and maintenance.
• Cost: The initial infrastructure cost for optical components, such as light sources (lasers/LEDs) and detectors, is higher compared to copper-based media.