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Computer Network and Infrastructure Transmission Media. Dr. E.C. Kulasekere. Section Objectives. Understand the principles behind media selection. The different types of guided media The different types of unguided media Understand the uses and applications of such media. Transmission Media. - PowerPoint PPT Presentation
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Computer Network and Computer Network and InfrastructureInfrastructure
Transmission MediaTransmission MediaDr. E.C. KulasekereDr. E.C. Kulasekere
April 19, 2023 2APIIT - 2004
Computer Network and Infrastructure
Section ObjectivesSection Objectives
Understand the principles behind media selection.Understand the principles behind media selection. The different types of guided mediaThe different types of guided media The different types of unguided mediaThe different types of unguided media Understand the uses and applications of such Understand the uses and applications of such
media.media.
April 19, 2023 3APIIT - 2004
Computer Network and Infrastructure
Transmission MediaTransmission Media
The characteristics and quality of a data The characteristics and quality of a data transmission is determine by both the transmission is determine by both the characteristics of the medium and the characteristics of the medium and the characteristics of the signal. characteristics of the signal.
The key concerns of transmissionThe key concerns of transmission Data rateData rate Distance of tx.Distance of tx.
April 19, 2023 4APIIT - 2004
Computer Network and Infrastructure
Media Design FactorsMedia Design Factors
BandwidthBandwidth Higher bandwidth gives higher data rateHigher bandwidth gives higher data rate
Transmission impairmentsTransmission impairments Attenuation limits the distance of transmissionAttenuation limits the distance of transmission
InterferenceInterference Particularly for unguided media with overlapping frequencies.Particularly for unguided media with overlapping frequencies.
Number of receiversNumber of receivers In guided mediaIn guided media More receivers (multi-point) introduce more attenuationMore receivers (multi-point) introduce more attenuation
April 19, 2023 5APIIT - 2004
Computer Network and Infrastructure
Classification of MediaClassification of Media
Guided Transmission MediaGuided Transmission Media Conductive MetalConductive Metal Glass or PlasticGlass or Plastic
Wireless Transmission MediaWireless Transmission Media Ground waveGround wave Sky waveSky wave Line-of-sightLine-of-sight
April 19, 2023 6APIIT - 2004
Computer Network and Infrastructure
Electromagnetic SpectrumElectromagnetic Spectrum
April 19, 2023 7APIIT - 2004
Computer Network and Infrastructure
Guided Transmission MediaGuided Transmission MediaConductive MetalConductive Metal
Twisted Pair Cables (TP)Twisted Pair Cables (TP) Shielded Twisted Pair (STP)Shielded Twisted Pair (STP) Unshielded Twisted Pair (UTP)Unshielded Twisted Pair (UTP)
UTP Data Transmission CategoriesUTP Data Transmission Categories Category 3 (up to 16 MHz)Category 3 (up to 16 MHz) Category 4 (up to 20 MHz)Category 4 (up to 20 MHz) Category 5 (up to 100 MHz)Category 5 (up to 100 MHz)
April 19, 2023 8APIIT - 2004
Computer Network and Infrastructure
UTP STP
Conductive MetalConductive MetalTwisted Pair CablesTwisted Pair Cables
April 19, 2023 9APIIT - 2004
Computer Network and Infrastructure
Conductive MetalConductive MetalShielded Twisted Pair CablesShielded Twisted Pair Cables
April 19, 2023 10APIIT - 2004
Computer Network and Infrastructure
Conductive MetalConductive MetalTwisted Pair …Twisted Pair …
• The twisting is done to reduce cross talk.
• Neighboring pairs may have different twist lengths.
April 19, 2023 11APIIT - 2004
Computer Network and Infrastructure
Twisted Pair ApplicationsTwisted Pair Applications
Most common mediumMost common medium Telephone networkTelephone network
Between house and local exchange (subscriber loop)Between house and local exchange (subscriber loop) Within buildingsWithin buildings
To private branch exchange (PBX)To private branch exchange (PBX) For local area networks (LAN)For local area networks (LAN)
10Mbps or 100Mbps10Mbps or 100Mbps
April 19, 2023 12APIIT - 2004
Computer Network and Infrastructure
Conductive MetalConductive MetalCoaxial CablesCoaxial Cables
Functionally Grouped into:Functionally Grouped into: BasebandBaseband: cable dedicated for only one channel: cable dedicated for only one channel BroadbandBroadband: cable can carry several analog signals (at : cable can carry several analog signals (at
different frequencies) simultaneously.different frequencies) simultaneously.
April 19, 2023 13APIIT - 2004
Computer Network and Infrastructure
Conductive MetalConductive MetalCoaxial Cable Physical LayoutCoaxial Cable Physical Layout
April 19, 2023 14APIIT - 2004
Computer Network and Infrastructure
Coaxial Cable ApplicationsCoaxial Cable Applications
Most versatile mediumMost versatile medium Television distributionTelevision distribution
Ariel to TVAriel to TV Cable TVCable TV
Long distance telephone transmissionLong distance telephone transmission Can carry 10,000 voice calls simultaneouslyCan carry 10,000 voice calls simultaneously Being replaced by fiber opticBeing replaced by fiber optic
Short distance computer systems linksShort distance computer systems links Local area networksLocal area networks
April 19, 2023 15APIIT - 2004
Computer Network and Infrastructure
Optical FiberOptical Fiber
April 19, 2023 16APIIT - 2004
Computer Network and Infrastructure
Optical Fiber - BenefitsOptical Fiber - Benefits
Greater capacityGreater capacity Data rates of hundreds of GbpsData rates of hundreds of Gbps
Smaller size & weightSmaller size & weight Lower attenuationLower attenuation Electromagnetic isolationElectromagnetic isolation Greater repeater spacingGreater repeater spacing
10s of km at least10s of km at least
April 19, 2023 17APIIT - 2004
Computer Network and Infrastructure
Wireless TransmissionWireless Transmission
Unguided mediaUnguided media Transmission and reception via antennaTransmission and reception via antenna DirectionalDirectional
Focused beamFocused beam Careful alignment requiredCareful alignment required
OmnidirectionalOmnidirectional Signal spreads in all directionsSignal spreads in all directions Can be received by many antennaeCan be received by many antennae
April 19, 2023 18APIIT - 2004
Computer Network and Infrastructure
Wireless Transmission MediaWireless Transmission MediaTerrestrial MicrowaveTerrestrial Microwave
April 19, 2023 19APIIT - 2004
Computer Network and Infrastructure
Wireless Transmission MediaWireless Transmission MediaSatellitesSatellites
April 19, 2023 20APIIT - 2004
Computer Network and Infrastructure
Wireless Transmission MediaWireless Transmission MediaGeostationary SatellitesGeostationary Satellites
April 19, 2023 21APIIT - 2004
Computer Network and Infrastructure
Wireless Transmission MediaWireless Transmission MediaOther MediaOther Media
Broadcast RadioBroadcast Radio Covers VHF and part of the UHFCovers VHF and part of the UHF Covers FM radio and UHF televisionCovers FM radio and UHF television
InfraredInfrared Line of sightLine of sight Omni directionalOmni directional
LasersLasers
April 19, 2023 22APIIT - 2004
Computer Network and Infrastructure
Review QuestionsReview Questions
What are some major advantages and What are some major advantages and disadvantages of microwave transmission?disadvantages of microwave transmission? Point-to-point microwave transmission Point-to-point microwave transmission
has a high data rate and less attenuation has a high data rate and less attenuation than twisted pair or coaxial cable. It is than twisted pair or coaxial cable. It is affected by rainfall, however, especially affected by rainfall, however, especially above 10 GHz. It is also requires line of above 10 GHz. It is also requires line of sight and is subject to interference from sight and is subject to interference from other microwave transmission, which other microwave transmission, which can be intense in some places.can be intense in some places.
April 19, 2023 23APIIT - 2004
Computer Network and Infrastructure
Review QuestionsReview Questions
Why must a satellite have distinct uplink and Why must a satellite have distinct uplink and downlink frequencies?downlink frequencies? In order to avoid interference from the uplink and In order to avoid interference from the uplink and
downlink signalsdownlink signals Indicate some significant differences between Indicate some significant differences between
broadcast radio and microwave.broadcast radio and microwave. Broadcast is omnidirectional, does not require dish Broadcast is omnidirectional, does not require dish
shaped antennas, and the antennas do not have to be shaped antennas, and the antennas do not have to be rigidly mounted in precise alignment.rigidly mounted in precise alignment.
April 19, 2023 24APIIT - 2004
Computer Network and Infrastructure
Review ProblemsReview Problems
Given a 100W power source, what is the maximum Given a 100W power source, what is the maximum allowable length for the following transmission allowable length for the following transmission media if a signal of 1W is to be received?media if a signal of 1W is to be received? 24-gauge (0.5mm) twisted wire operating at 300kHz24-gauge (0.5mm) twisted wire operating at 300kHz 24-gauge (0.5mm) twisted wire operating at 1MHz24-gauge (0.5mm) twisted wire operating at 1MHz 0.375in (9.5mm) coaxial cable operating at 1MHz0.375in (9.5mm) coaxial cable operating at 1MHz 0.375in (9.5mm) coaxial cable operating at 25MHz0.375in (9.5mm) coaxial cable operating at 25MHz Optical fiber operating at its optimal frequency.Optical fiber operating at its optimal frequency.
April 19, 2023 25APIIT - 2004
Computer Network and Infrastructure
Review ProblemsReview Problems
The allowable power loss is 10 log 100 = 20 dBa. From Figure in next page, the attenuation is
about 13 dB per km.Length = (20 dB)/(13 dB per km) = 1.5 km
b. Length = (20 dB)/(20 dB per km) = 1 kmc. Length = (20 dB)/(2.5 dB per km) = 8 kmd. Length = (20 dB)/(10 dB per km) = 2 kme. Length = (20 dB)/(0.2 dB per km) = 100 km
April 19, 2023 26APIIT - 2004
Computer Network and Infrastructure
