Guided Transmission Media in Computer Networks
- 2. • Guided transmission media in computer networks refer to physical pathways that guide the data signals along a specific path. These media involve the use of cables or wires to transmit data between devices. The three main types of guided transmission media are • 1. Twisted-pair cables • 2. Coaxial cables • 3. Fiber-optic cables.
- 3. 1. Twisted-Pair Cables Description: • Twisted-pair cables consist of pairs of insulated copper wires twisted together. The twisting helps to reduce electromagnetic interference from external sources and crosstalk between adjacent pairs. Types: • Unshielded Twisted Pair (UTP): The most common type used in networking, particularly in Ethernet cables (e.g., CAT5, CAT6). • Shielded Twisted Pair (STP): Similar to UTP but with an additional shielding layer to reduce interference. Applications: • Widely used in local area networks (LANs), telephone systems, and other short-distance communication systems.
- 5. Advantages: • Cost-effective: Generally cheaper than other guided media. • Flexible and easy to install: UTP cables are lightweight and can be easily routed through walls and ceilings. • Widely supported: Compatible with many network devices and standards. Disadvantages: • Limited bandwidth and distance: UTP cables have lower bandwidth compared to coaxial and fiber-optic cables, making them less suitable for high-speed or long-distance communication. • Susceptible to interference: Although twisted pairs reduce interference, UTP is still more susceptible to electromagnetic interference (EMI) than shielded cables or fiber optics. • Signal attenuation: Over long distances, signal degradation (attenuation) can occur.
- 6. 2. Coaxial Cables Description: • Coaxial cables consist of a central copper conductor surrounded by an insulating layer, a metallic shield, and an outer insulating layer. The shielding provides better protection against electromagnetic interference. Types: • Thicknet (10Base5): Used in older Ethernet networks, capable of longer distances. • Thinnet (10Base2): A thinner and more flexible version used in some older LANs. • Modern Coaxial: Used for cable television, broadband internet, and other communication systems. Applications: • Used in cable television networks, broadband internet connections, and older Ethernet networks.
- 8. • Advantages: • Higher bandwidth: Supports higher data rates than twisted-pair cables. • Better shielding: Provides better protection against interference and crosstalk. • Longer distance: Can transmit signals over longer distances without significant attenuation compared to twisted-pair cables. • Disadvantages: • Bulkier and less flexible: Coaxial cables are thicker and less flexible than twisted-pair cables, making them harder to install in tight spaces. • More expensive: Coaxial cables are generally more expensive than twisted-pair cables. • Decreasing use in LANs: With the advent of faster Ethernet standards and fiber optics, coaxial cables are less commonly used in modern LANs.
- 9. 3. Fiber-Optic Cables Description: • Fiber-optic cables transmit data as pulses of light through thin strands of glass or plastic fibers. They consist of a core (which carries the light signals), cladding (which reflects light back into the core), and a protective outer jacket. Types: • Single-mode fiber (SMF): Has a small core that allows only one light mode to propagate, ideal for long-distance communication. • Multi-mode fiber (MMF): Has a larger core that allows multiple light modes to propagate, suitable for shorter distances. Applications: • Used in high-speed data networks, internet backbone connections, and long-distance telecommunications.
- 11. Advantages: • Extremely high bandwidth: Fiber-optic cables can support very high data rates, making them ideal for high-speed networks. • Long-distance transmission: Can transmit data over much longer distances without significant signal loss compared to copper cables. • Immunity to electromagnetic interference: Because they use light, fiber-optic cables are not affected by electromagnetic interference or radio-frequency interference. Disadvantages: • High cost: More expensive to install and maintain than copper-based cables. • Fragility: Glass fibers are more delicate and prone to damage from bending or mishandling. • Complex installation: Requires specialized equipment and skills for installation and splicing.
- 12. Thankyou Made By Sukanya Rakshit