Lecture3
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This document discusses various physical media used for networking, including copper-based media like coaxial cable and twisted pair cables, optical fiber, and wireless technologies. It provides details on the characteristics of different cable types like category ratings for unshielded twisted pair cables and specifications for multimode and singlemode optical fiber. Wireless technologies are categorized by their typical range as short, medium, or long. Frequency bands used by different wireless applications are also outlined.
Lecture3
- 1. Physical Media PHYSICAL MEDIA
- 2. Physical Media Physical Media
- 3. Physical Media Physical Media Copper Coaxial Cable - Thick or Thin Unshielded Twisted Pair - CAT 3,4,5,5e&6 Optical Fiber Multimode Singlemode Wireless Short Range Medium Range (Line of Sight) Satellite
- 4. Physical Media Copper Media: Coaxial Cable Coaxial cable is a copper-cored cable surrounded by a heavy shielding and is used to connect computers in a network. Outer conductor shields the inner conductor from picking up stray signal from the air. High bandwidth but lossy channel. Repeater is used to regenerate the weakened signals. Category Impedance Use RRGG--5599 75 W Cable TV RRGG--5588 50 W Thin Ethernet RRGG--1111 50 W Thick Ethernet
- 5. Physical Media Copper Media: Twisted Pair Twisted-pair is a type of cabling that is used for telephone communications and most modern Ethernet networks. A pair of wires forms a circuit that can transmit data. The pairs are twisted to provide protection against crosstalk, the noise generated by adjacent pairs. There are two basic types, shielded twisted-pair (STP) and unshielded twisted-pair (UTP).
- 6. Physical Media Shielded Twisted Pair (STP)
- 7. Physical Media Unshielded Twisted Pair (UTP)
- 8. Physical Media Unshielded Twisted Pair (UTP) Consists of 4 pairs (8 wires) of insulated copper wires typically about 1 mm thick. The wires are twisted together in a helical form. Twisting reduces the interference between pairs of wires. High bandwidth and High attenuation channel. Flexible and cheap cable. Category rating based on number of twists per inch and the material used CAT 3, CAT 4, CAT 5, Enhanced CAT 5 and now CAT 6.
- 9. Categories of UTP Physical Media UTP comes in several categories that are based on the number of twists in the wires, the diameter of the wires and the material used in the wires. Category 3 is the wiring used primarily for telephone connections. Category 5e and Category 6 are currently the most common Ethernet cables used.
- 10. Physical Media Categories of UTP: CAT 3 Bandwidth 16 Mhz 11.5 dB Attenuation 100 ohms Impedance Used in voice applications and 10baseT (10Mbps) Ethernet
- 11. Physical Media Categories of UTP: CAT 4 20 MHz Bandwidth 7.5 dB Attenuation 100 ohms Impedance Used in 10baseT (10Mbps) Ethernet
- 12. Physical Media Categories of UTP: CAT 5 100 MHz Bandwidth 24.0 dB Attenuation 100 ohms Impedance Used for high-speed data transmission Used in 10BaseT (10 Mbps) Ethernet & Fast Ethernet (100 Mbps)
- 13. Physical Media Categories of UTP: CAT 5e 150 MHz Bandwidth 24.0 dB Attenuation 100 ohms Impedance Transmits high-speed data Used in Fast Ethernet (100 Mbps), Gigabit Ethernet (1000 Mbps) & 155 Mbps ATM
- 14. Physical Media Categories of UTP: CAT 6 250 MHz Bandwidth 19.8 dB Attenuation 100 ohms Impedance Transmits high-speed data Used in Gigabit Ethernet (1000 Mbps) & 10 Gig Ethernet (10000 Mbps)
- 15. Fiber Media Physical Media Optical fibers use light to send information through the optical medium. It uses the principal of total internal reflection. Modulated light transmissions are used to transmit the signal.
- 16. Physical Media Total Internal Reflection
- 17. Fiber Media Physical Media Light travels through the optical media by the way of total internal reflection. Modulation scheme used is intensity modulation. Two types of Fiber media : Multimode Singlemode Multimode Fiber can support less bandwidth than Singlemode Fiber. Singlemode Fiber has a very small core and carry only one beam of light. It can support Gbps data rates over > 100 Km without using repeaters.
- 18. Physical Media Single and Multimode Fiber Single-mode fiber Carries light pulses along single path Uses Laser Light Source Multimode fiber Many pulses of light generated by LED travel at different angles
- 19. Fiber Media Physical Media The bandwidth of the fiber is limited due to the dispersion effect. Distance Bandwidth product of a fiber is almost a constant. Fiber optic cables consist of multiple fibers packed inside protective covering. 62.5/125 μm (850/1310 nm) multimode fiber 50/125 μm (850/1310 nm) multimode fiber 10 μm (1310 nm) single-mode fiber
- 20. Fiber-Optic Cable Physical Media Contains one or several glass fibers at its core Surrounding the fibers is a layer called cladding
- 21. Fiber Optic Cable Physical Media FO Cable may have 1 to over 1000 fibers
- 22. Wireless Media Physical Media Very useful in difficult terrain where cable laying is not possible. Provides mobility to communication nodes. Right of way and cable laying costs can be reduced. Susceptible to rain, atmospheric variations and Objects in transmission path.
- 23. Wireless Media Physical Media Indoor : 10 – 50m : BlueTooth, WLAN Short range Outdoor : 50 – 200m: WLAN Mid Range Outdoor : 200m – 5 Km : GSM, CDMA, WLAN Point-to-Point, Wi-Max Long Range Outdoor : 5 Km – 100 Km : Microwave Point-to-Point Long Distance Communication : Across Continents : Satellite Communication
- 24. FFrreeqquueennccyy BBaannddss Physical Media BBaanndd RRaannggee PPrrooppaaggaattiioo nn AApppplliiccaattiioonn VVLLFF 3–30 KHz Ground Long-range radio navigation LLFF 30–300 KHz Ground Radio beacons and navigational locators MMFF 300 KHz–3 MHz Sky AM radio HHFF 3–30 MHz Sky Citizens band (CB), ship/aircraft communication VVHHFF 30–300 MHz Sky and line-of-sight VHF TV, FM radio UUHHFF 300 MHz–3 GHz Line-of-sight UHF TV, cellular phones, paging, satellite SSHHFF 3–30 GHz Line-of-sight Satellite communication EEHHFF 30–300 GHz Line-of-sight Long-range radio navigation
- 25. Wireless LAN Physical Media Internet Router Switch Access Point Access Point PC PC
- 26. Terrestrial Microwave Physical Media Microwaves do not follow the curvature of earth Line-of-Sight transmission Height allows the signal to travel farther Two frequencies for two way communication Repeater is used to increase the distance Hop-by-Hop
- 27. Physical Media Satellite Communication