Types of Network and Transmission Media
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The document outlines various types of networks categorized by area coverage, including LANs (local area networks), MANs (metropolitan area networks), and WANs (wide area networks), describing their geographical scope, setup costs, and data transfer rates. It also details different transmission media such as twisted pair cables, coaxial cables, fiber-optics, microwaves, radio waves, and infrared waves, explaining their characteristics, speed, and common uses. The document highlights the importance of selecting appropriate media for effective data transmission and communication.
Types of Network and Transmission Media
- 1. Types of Network and Transmission Media Mr. Roshan Bhattarai Kathmandu, Nepal
- 2. Types of Network (Area Coverage) 1. LAN (Local Area Network) • Designed to connect personal computers and other digital devices within 500 meter radius • Connects few computers in a building/several buildings in close proximity • LAN can connect to long distance networks through Internet • Lowest network setup cost • Highest bandwidth of data transfer, usually supports data transfer rates of 100 Mbps to 1 Gbps • Eg: Ethernet, wifi
- 3. 2. MAN (Metropolitan Area Network) • Network that spans a metropolitan area, usually a city (within 50 km radius) • Geographic scope falls between a LAN and a WAN • Moderate network setup cost • Moderate bandwidth of data transfer, usually supports data transfer rates 50 to 100 Mbps • Eg: Cable TV network, Traffic light monitoring system etc
- 4. 3. WAN (Wide Area Network) • Network spans broad geographical distances- entire region, states, country or the entire world • Computers connect through public networks, such as telephone systems, leased lines or satellites • Network is more vulnerable to threats • Lowest bandwidth of data transfer, usually supports 10 to 50 Mbps • Highest network setup cost • Eg: The most universal and powerful WAN in the Internet, Telecommunication network etc
- 5. Transmission Media • Transmission media is a pathway that carries the data from sender to receiver device. • We use different types of cables or waves to transmit data • Data is transmitted normally through electrical or electromagnetic signals • Electrical signal is in the form of current • Electromagnetic signal is series of electromagnetic energy pulses at various frequencies
- 6. Types of Transmission Media
- 7. a) Twisted pair cable • Consists of strands of copper wire twisted in pairs • Twist is done to reduce the effect the electromagnetic interference produced during data transmission • Can obtain speed up to 1 Gbps in short distance • Cabling is limited to a maximum recommended run of 100 meters • Comparatively cheaper, less capacity • Simple to install • Usually used in LANs
- 8. b) Coaxial Cable • Consists of thickly insulated copper wire • Can transmit larger volume of data than TPC • Can obtain speed up to 1 Gbps • Comparatively expensive and higher quality than TPC • Simple to install • Usually used in LANs and MANs
- 9. c) Fiber-Optics (Optical fiber) • Consists of strands of hair thin plastic/glass filaments • Data are transmitted into pulses of light by a laser device (Total Internal Reflection technology is used) • Very high data transfer speed compared to other cables • Expensive and better quality transfer • Can obtain speed up to several trillions bits per second • installation & maintenance is difficult • Used in MANs and WANs
- 10. a) Microwave (Terrestrial and Satellite) • Electromagnetic waves ranging in frequencies between 1 to 300 GHz are normally called micro waves • Microwaves are considered to be very short radio waves (high frequency and high-energy waves) • Transmits high frequency signals through the atmosphere • Widely used for high volume, long distance communication • Microwave signals follow straight line and do not bend with curvature of the earth • Transmissions (Relay) stations be positioned about 30 miles apart for long distance (terrestrial microwave) • For very long and geographically dispersed transmission, Communication satellites are used as relay stations
- 11. • Satellites are in the geostationary orbit which is 22000 miles above the earth • Satellites operates as repeaters with receiving antenna, transponder and transmitting of signals
- 12. b) Radio Waves • Electromagnetic waves ranging in frequencies between 3 KHz and 1 GHz are normally called radio waves • Radio waves are the lowest-energy, lowest-frequency and longest-wavelength electromagnetic waves. • Radio waves are Omni-directional • When an antenna transmits radio waves, they are propagated in all directions, sending and receiving antennas do not have to be aligned. • A sending antenna send waves that can be received by any receiving antenna. • Radio waves, particularly with those of low and medium frequencies, can penetrate walls.
- 13. • The Omni-directional characteristics of radio waves make them useful for multicasting in which there is one sender but many receivers. • AM and FM radio, television, cordless phones etc are examples of multicasting.
- 14. c) Infrared Waves • Infrared waves are used in extremely small distance communication as they cannot go through obstacles • The range of frequency of these waves is 300GHz to 400THz. • These waves are used in TV remotes, keyboards, wireless mouse, printer, etc. • When we use infrared remote control, we do not interfere with the use of the remote by our neighbours. • useless for long-range communication. • cannot use infrared waves outside a building because the sun's rays contain infrared waves that can interfere with the communication.