Transmission medium used in LAN is.............

Question

Accepted Answer

The correct option is (1):
Co-axial cable was one of the foundational and earliest transmission media widely used to build Local Area Networks (LANs), particularly under the original Ethernet standards such as 10BASE2 (Thin Ethernet) and 10BASE5 (Thick Ethernet). A coaxial cable consists of a central conductor, surrounded by an insulator and a metallic shield, which gives it excellent resistance to electromagnetic interference. This shielding characteristic makes it a robust and reliable choice for carrying high-frequency signals over a localized area. Although modern LANs are now dominated by twisted pair cables (like Cat5e/6 UTP) and optical fiber for backbone links, coaxial cable remains a historically correct and technically valid answer, especially when considering the options provided. Its design allowed it to function effectively as a shared medium in early networking architectures.

The incorrect option is (2):
Optical fibre is a highly advanced transmission medium that transmits data using light signals through glass or plastic strands. While it is certainly used extensively in modern networking, it is typically deployed for the *backbone* or *inter-building* links within a very large LAN or for high-speed WAN connections, as it offers the highest bandwidth and can cover very long distances without signal loss. Optical fibre is generally more expensive to install, terminate, and maintain than coaxial cable, making it less common as the primary medium for connecting individual user devices within a standard, small or medium-sized LAN environment.

The incorrect option is (3):
Microwave transmission utilizes radio waves for communication, classifying it as an unguided, wireless medium. This technology is primarily used for point-to-point communication over long distances, often to link geographically separate Local Area Networks to create a Metropolitan Area Network (MAN) or Wide Area Network (WAN). Microwave links are established between antennas on towers or rooftops and are not practically used to connect end-user devices *within* the localized, small-area scope of a typical LAN.

The incorrect option is (4):
Satellite transmission is a classic example of a Wide Area Network (WAN) communication medium. It involves sending signals to and receiving signals from orbiting satellites to cover very large, global geographical areas. The inherent properties of satellite communication, such as high latency (delay) and the vast distances covered, make it entirely unsuitable for the localized, low-latency, and high-speed data exchange requirements of an internal Local Area Network.