Lecture 7 Cabling:Types and Termination

TIA/EIA 568 Standards TIA/EIA-568A Commercial Building

Telecommunications Cabling Standard

TIA/EIA-568B

TIA/EIA 569-A

Commercial Building Standards for Telecommunications Pathways and Spaces (ANSI/TIA/EIA-569-A-98)

TIA 606-AAdministration Standard for the Telecommunications Infrastructure of Commercial Buildings

TIA-606-A Feb. 1993… to provide a uniform administration scheme

that is independent of applications, which may change several times throughout the life of a building.

This standard establishes guidelines for owners, end users, manufacturers, consultants, contractors, designers, installers, and facilities administrators involved in the administration of the telecommunications infrastructure or related administration system.

The Six Subsystems of a Structured Cabling System 1.Building Entrance 2.Equipment Room 3.Backbone Cabling

Specified Topology 4.Telecommunications Closet 5.Horizontal Cabling

Specified Topology Maximum Distances Telecommunications Outlet 8-Position Modular Jack Pair Assignments

6.Work Area

Scope of the TIA/EIA-568A Standard Minimum requirements for

telecommunications cabling within an office environment

Recommended topology and distances Media parameters which determine

performance Connector and pin assignments to ensure

inter-connectability The useful life of telecommunications cabling

systems as being in excess of ten years

568A Implementation offers voice and data to each workstation Mandates 2 jacks (1 for voice 1 for data) per

station Voice Jacks 4 pair 100 Ohm Category 3 or

better Data Jacks 4 Pair Category 5 or Better or

multi-mode fiber.

Media Types

Unshielded Twisted Pair (UTP) Cable Shielded Twisted Pair Cable (STP) Single and Multi-Mode Fiber Coaxial Cable (Grand-fathered into but

not recognized by the TIA/EIA 568 A standard).

UTP Cables A communications cable using one or

more pairs of wires that are twisted together. When driven as a balanced line, the twisting reduces the susceptibility to external interference and the radiation of signal energy.

UTP (Unshielded Twisted Pair)

Most Common type of cable installed in buildings.

Most common media for Ethernet and LAN cabling.

Often used in conjunction with Telephone distribution

Unshielded Twisted Pair is smaller, more flexible, and less expensive then Shielded Twisted Pair.

Four Pair, 24 Gauge 100 Ohm copper cable

Balanced PVC or Plenum Jacket Types of UTP Cable: Category 3, 4,

5, and “Enhanced Category 5” or Category 6

Twist Pitch used in UTP cabling to identify the

different length distance of different pairs within a single cable. The twist pitch varies between pairs to reduce the affects of NEXT or signals jumping from one pair to another.

Category 3 Transmission Frequencies up to 16 MHz Intended for low speed data, telephone, 4

Mbs Token Ring, and 10 Mbs Ethernet applications.

Category 4

Transmission Frequencies up to 20 MHz

Suitable for all category 3 applications as well as 16 Mbs Token Ring

Category 5 Transmission Frequencies up to 100 MHz Most popular for high speed applications Suitable for all Category 3 and 4 applications as

well as any copper based voice, video, or data application such as: 100 Mbs "Fast Ethernet", CDDI (FDDI over Copper), and possibly Gigabit Ethernet over copper.

Enhanced Category 5 and Category 6 High frequency applications such as Gigabit Ethernet

and certainly ATM will require better and higher bandwidth cables than originally specified by the Category 5 standard. While Gigabit Ethernet should be compatible with Category 5 cabling, it is suggested that cabling for high speed applications including Fast Ethernet should exceed Category 5 standards.

New standards are under development for such cabling, however “enhanced Category 5” cabling is available

now.

UTP Summary Characteristics

Four Pair, 24 Gauge 100 Ohm copper cable Unbalanced PVC or Plenum Jacket Types of UTP Cable: Category 3, 4, 5, and "Enhanced Category 5" or Category 6

Category 3 Transmission Frequencies up to 16 MHz intended for low speed data, telephone, 4 Mbps Token Ring, and 10 Mbps Ethernet applications.

Category 4 Transmission Frequencies up to 20 MHz Suitable for all category 3 applications as well as 16 Mbps Token Ring

Category 5 Transmission Frequencies up to 100 Mhz Most popular for high speed applications Suitable for all Category 3 and 4 applications as well as any copper based voice, video, or data

application such as: 100 Mbps "Fast Ethernet", CDDI (FDDI over Copper), and ATM.

Enhanced Category 5 and Category 6 High frequency applications such as Gigabit Ethernet and certainly ATM will require better and

higher bandwidth cables than originally specified by the Category 5 standard. While Gigabit Ethernet should be compatible with Category 5 cabling, it is suggested that cabling for high speed applications including Fast Ethernet should exceed Category 5 standards.

New standards for such cabling is underway.

UTP Installation Considerations

Unshielded Twisted Pair is smaller, more flexible, and less expensive then Shielded Twisted Pair.

The Entire link or infrastructure (including jacks and cross connect blocks) must be composed of Category 5 components.

All cables and components must be installed and terminated properly to achieve Category 5 standards.

Maximum distance of horizontal cabling is 295 feet (90 meters).

Patch cords max length 6m Horizontal Cabling 90 m Equipment Cords 2 m Maximum pull tension for Category 5 UTP is 25 foot lbs.

(to avoid stretching the twists of the pairs). 12" Minimum distance from florescent lighting 5" Minimum distance between power and data cables. Minimum bend radius of 1 to 4 inches Cables must be dressed, labeled, and managed Cable ties must not be tightened (Velcro is better) No staples At termination points the jacket should be striped as little

as possible < 1/2 ".

Stranded UTP vs.. Solid UTP Stranded UTP

usually used for patch cables wires or conductors are made of many

flexible strands in order to make the wire stronger and more flexible.

stranded UTP is not suitable for longer distances due to its lower efficiency than Solid UTP.

Solid UTP usually used in horizontal wiring (wiring to

jacks) in which the wires or conductors are solid.

Solid UTP cables are less flexible and more brittle than stranded cables, however they are cheaper and more efficient.

Cable Distribution •Cable Distribution Equipment

UTP (Unshielded Twisted Pair)•UTP Cable Termination Tools

•UTP Connectors, plugs, jacks, and patch Panels

• UTP Cable Certification and Testing

Shielded Twisted Pair Thin-Net Coaxial Cable Optical Fiber

• Multi-Mode fiber

• Single Mode Fiber

• Fiberoptic Connectors

UTP Cable Termination Tools

Punch Blocks Crimp Tools

UTP Connectors

plugs jacks patch Panels patch cables labels

TIA/EIA 568 Standard

Transceivers AUI connectors Media converters

Thin Net Coax (Coaxial Cable) Used for 10Base 2 Ethernet. Coax is primarily used for its self shielding properties, low

attenuation at LAN frequencies, and installation expense. The construction of the cable greatly reduces susceptibility to

outside interfering signals and noise, as well as minimizing the radiated emissions from the cable. 

Jacket- (sheath) The outer protective covering of a cable. Center Conductor   Inner part of a Thin- net (coaxial cable). Center conductor

or wire on which the LAN signal is carried. See Thin-net, shield, braided wire shield, foil shield, 10Base 2."

Insulation   A material which is nonconductive to the flow of electric current. The coating (usually plastic) of a conductor which insulates it from other conductors.

Shield   A metallic foil or multi-wire screen mesh that is used to prevent electromagnetic fields from penetrating or exiting a transmission cable.

Optical Fiber

Multi-Mode fiber most commonly used in LANs and MANs. A fiber wave guide which supports the propagation

of multiple modes. Multi-mode fiber may have a typical core diameter of

50 to 100 um with a refractive index that is graded or stepped.

It allows the use of inexpensive LED light sources and connector alignment and coupling is less critical than with single mode fiber.

Distances of transmission and transmission bandwidth are less than single mode fiber due to dispersion of the light signal.

Single Mode Fiber A fiber wave guide in which only one mode will

propagate. Single mode fiber has a very small core diameter, in some fibers aprox. 8 micron. It allows signal transmission for long fiber distances with relatively high bandwidth and is generally driven with a laser diode."

Indoor Fiber-optic Cables

Fiber-optic Connectors ST SC FSD

ST

SC

FSD

Fiber Termination Techniques

Breakout Cable Epoxy Crimp UV Cure Epoxy Air Blown Fiber

Cable Properties and Characteristics

AttenuationNEXTTesting

Attenuation

Attenuation refers to the power loss an electrical signal experiences as it travels through a cable.

Communications equipment operates by detecting signal variations (which becomes more difficult as the signal becomes weaker).

In a Category 5 system TIA/EIA 568A limits attenuation to 24 dB for 100 MHz signal.

20 db of attenuation means that only 1/100 th of the original signal reaches its destination.

the lower the dB means the stronger the signal Distance, higher frequencies and high temperatures increase

attenuation.

UTP Cable Certification and Testing

Attenuation and Near End Cross Talk (NEXT) are the two most crucial electrical parameters that distinguish performance characteristics of twisted pair cable.

Attenuation Attenuation is the loss of communication signal energy.

Represented in dB or decibels. Decibels Attenuation and NEXT are reported in negative (- dB). Attenuation and NEXT dB are relative measures of changes in

voltage. dB loss has a logarithmic progression.

• 3 dB = 2X

• 10 dB = 10X

• 20 dB = 100X

• 30 dB = 1,000X

• 40 dB = 10,000X

• 50 dB = 100,000X

• 60 dB = 1,000,000X

Near End Cross Talk (NEXT)

NEXT occurs when a portion of the signal energy jumps from one pair in a cable to another.

Cables are most susceptible to cross talk near their ends, or close to devices.

In a UTP cable one or two pairs are used to transmit signals while the other pair or pairs receive.

Close proximity of the transmit pairs increases NEXT. The first 50 or 60 ft of a cable run are the most susceptible to

NEXT. Cross connects are especially susceptible to NEXT.

Too much signal "noise" prevents the receiver from distinguishing transmit form receive signals and results in garbled transmission and poor network performance.

 

Attenuation to Cross Talk margin

• Category 3 Category 4 Category 5

Attenuation per 100m 13.1 dB 8.9 dB 8.2 dB NEXT 23 dB 38 dB 44 dB Peak Frequency 16 MHz 20 MHz 100 MHz

Pair Scanners Pair Scanners CAT 5 Pair Scanner (Cable Tester) CAT 5 Pair Scanners Differ from normal Pair Scanners

in that they test all pairs of the cables at various frequencies up to 100 MHz.

Measures each pair for Distance (Including Twist Pitch)