Type of Data Cables
Unshielded Twisted-Pair (UTP)
Shielded Twisted-Pair (STP)
Screened Twisted-Pair (SCTP)
Coaxial Cable (COAX)
Fiber-Optic Cable (FO)
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Unit 3
Key Concept 1: Cable Types
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UTP
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Four Pairs of Copper Cable
Number of twists varies per inch
No shielding
Very easy to work with
Most common cable for LAN
Cat 3, Cat 5, Cat 5e, Cat 6, Cat 7 will be defined in standards later in the course
◦ Most susceptible to
Electromagnetic Interference
(EMI)
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Similar to UTP
Pairs shielded
Core shielded
SCTP o o
Hybrid of STP and UTP
Foil shield or screen
Both the cables must be grounded end to end with no gaps in shield coverage.
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STP o
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Coax
Single conducting core
Core shield
Mesh shield
50 Ohm RG-58 (thinnet) is for outdated 10Base-2
Ethernet
◦ 75 Ohm RG-6U commonly used for highdefinition television (HDTV) and broadband data applications
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FO
◦ Central glass core
◦ Cladding prevents light loss
◦ Dielectric strengthening material protects core
◦ Single strand, dual strand
(pictured), and multistrand cables are common
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Single-Mode Fiber Optic (FO)
Single-Mode Fiber
Optic (FO)
Multimode Fiber
Optic (FO)
◦ Single beam
◦ Smaller core
◦ Usually WAN
Multimode Fiber Optic (FO)
◦ Multiple beams
◦ Larger core
◦ Usually LAN
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Usage
◦ General Purpose
◦ Plenum
◦ Riser
UTP
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Twists per inch
Gauge (thickness)
Length
Solid/Stranded
Before standards:
◦ Vendor-Specific cabling locked customers into ONE vendor
◦ Upgrades often required whole new cabling systems
◦ Movement of equipment required reconfiguring of cabling
◦ Companies had to buy and troubleshoot several different cable systems Unit 3
Key Concept 2: Standards, Specifications and Codes
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◦ Proprietary systems often required expensive training to service 11
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What are standards?
◦ Standards represent agreements between scientists, manufacturers, and customers
◦ Standards allow different devices to connect seamlessly since they work off the same rules
◦ TCP/IP standards allow all your PC, XBOX, and digital phone to communicate
◦ Bluetooth allows our phones to communicate with our cars and earpieces because they use a standard
◦ Wiring standards allow phones, printers, computers, and other devices to share the same infrastructure
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De Facto
“Standard” because of their usage
Example: Everyone does it naturally – English is the standard language in the U.S. although not the legal language Specific rules formulated by formal groups
“Standard” because of rules
Example: Everyone does it by requirement – driving on the right side of the road in the U.S. because it is law
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American National Standards Institute (ANSI)
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◦ Founded in 1918
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Electronic Industries Alliance (EIA)
◦ Founded in 1924
◦ Manufacturers’ consortium
◦ Electronics sectors include:
◦ 5 engineering societies
◦ 3 government agencies
◦ Over 1,400 private companies
◦ Encourage voluntary compliance with adopted standards and methods Copyright 2012, ITT ESI
Where do standards come from?
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Telecommunications Industry Association (TIA)
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◦ Founded in 1924, partner with EIA
◦ Added the United States Telecommunications Suppliers
Association (USTSA) in 1988
◦ Over 1,100 telecommunications and electronics companies
◦ Advocates for its worldwide membership regarding:
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Insulated Cable Engineers Association (ICEA)
◦ Founded in 1925
◦ Nonprofit organization
◦ Cable manufacturers and engineers
◦ Primarily concerned with generating standards for
