Cabling Structured Cabling Standards

CablingStructured Cabling

Standards

Structured Cabling

Structured Cabling is the foundation for any communications installation.

An appropriate cabling installation ensures the proper operation of equipment, manageability, organization, and expandability of a communications network.

Network Cabling In the early 1980's a variety of cable types and

designs were utilized. Coaxial and twin-axial cables were the most popular.

Proprietary (non-standardized) designs were predominant.

Today cabling and devices have been standardized in a way which makes them interoperable and compatible in almost any implementation.

Standards Bodies

These organizations are composed of representatives from various distributors, manufacturers, and customers in the communications industry ANSI - American National Standards

Institute TIA - Telecommunication Industry

Association EIA - Electronics Industry Association

EIA/TIA-568 - first version of the standard published July of 1991. TSB-36 August of 1991 a Technical Systems Bulletin

specifications for higher grades (Cat 4, Cat 5) of UTP. TSB-40August of 1992 TSB-40 published addressing higher grades of

UTP connecting hardware. TSB-40A UTP patch cords in more detail, and to clarify testing

requirements for UTP modular jacks. TIA/EIA-568A/(CSA T529) Commercial Telecommunications Cabling

Standard EIA/TIA-569/(CSA T530) Commercial Building Standard for

Telecommunications Pathways and Spaces EIA/TIA-570/(CSA T525) Residential and Light Commercial

Telecommunications Wiring Standard TIA/EIA-606/(CSA T528) Administration Standard for the

Telecommunications Infrastructure of Commercial Buildings TIA/EIA-607/(CSA T527) Commercial Building Grounding/Bonding

Requirements TSB-67 Transmission Performance Specifications for Field Testing of

Unshielded Twisted-Pair Cabling Systems

TSB-72 Centralized Optical Fiber Cabling Guidelines

Commercial Building Telecommunications Cabling Standard (ANSI/TIA/EIA-568-A-95) Committee: TR-41.8.1 Published:October 25, 1995 Category: Telecommunications Description: This standard specifies a

generic telecommunications cabling system for commercial buildings that will support a multiproduct, multivendor environment. It also provides information that may be used for the design of telecommunications products for commercial enterprises. The purpose of this standard is to enable the planning and installation of a structured cabling system for commercial buildings

TIA/EIA-569-A

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

Committee: TR-41.8.3 Published:October 24, 1990 Category: Telecommunications Description: This Standard encompasses

telecommunications considerations both within and between buildings. The aspects covered are the pathways into which telecommunications media are placed and the rooms and areas associated with the building used to terminate media and install telecommunications equipment.

Purpose of the TIA/EIA-568A Standard

Establish a generic telecommunications cabling standard that will support a multivendor environment

Enable the planning and installation of a structured cabling system for commercial buildings

Establish performance and technical criteria for various cabling systems configurations

TSB-67 Transmission Performance Specification for Field Testing of Unshielded Twisted Pair Cabling Systems

TSB-67 defines the allowable worst case attenuation and NEXT for an installed link.

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

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

TIA/EIA 568A Sub Systems

1. Entrance Facility

Point where outside plant cables and associated hardware are brought into the building. Cables from the outside end in an

Equipment Room which is the main distribution point for the building. This is often called the BDF (Building Distribution Frame).

2. Equipment Room

A centralized space for communications equipment. Equipment Rooms often contain cabling

distribution equipment. “Patch Panels” and “Cross Connect

Blocks” are used to terminate or end cables and to connect them with other cables and equipment.

3. Backbone Cabling

Interconnections between closets and equipment rooms within a single building or between other buildings. Large buildings may contain several

distribution points or Telecommunications Closets which are necessary to overcome distance limitations.

Risers are Vertical cable runs which connect Telecommunications Closets on different floors.

4. Telecom. Closet

A space where horizontal distribution cables are terminated. All cable and media types must be

terminated on compatible connecting hardware.

Backbone cables are also terminated in the closet. Cross connection is done with jumpers or patch cords to provide flexible connectivity.

5. Horizontal Cabling

Physical media used to connect each outlet to a closet. Horizontal Cables span from

Telecommunications closets to the wall jacks with which users connect their equipment.

Copper Cables, Coaxial Cables, and Fiberoptic cables may be used.

6. Work Area

Connections and cabling on the other side of the telecommunications jack.

Horizontal Cabling Distance Specifications

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).

Media and Connecting Hardware Performance Specifications of the 568 Standard Media and Connecting Hardware

Performance Specifications 100 Ohm Unshielded Twisted Pair

(UTP) Cabling Systems Horizontal Cable Backbone Cable UTP Connecting Hardware and Cords

150 Ohm Shielded Twisted Pair (STP-A) Cabling Systems Horizontal and Backbone STP-A Cable

150 Ohm STP-A Data Connector 150 Ohm STP-A Patch Cable

Optical Fiber Cabling Systems Optical Fiber Cabling Media Optical Fiber Connector Optical Fiber Telecommunications Outlet

TSB-67 Standard

Shielded Twisted Pair (STP) Developed by IBM for Token Ring Rated at 20 MHz Newer STP 568 A systems can achieve 300

MHz Electrical Performance of Twisted Pair Cable Uses electrical signals to carry data STP cabling systems are more expensive and

harder to install and maintain than UTP cabling systems, but are not necessarily better.

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.

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.

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

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 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.

TIA/EIA 568-A/B  Modular Plug Termination

8 Pin Modular plugs are used to terminate UTP patch cables.

Such cables are identical on either end (strait through)

Two “standards” are available. 568A and 568 B.

TIA/EIA 568-A/B  Modular Jack Termination Modular Jacks are used in patch

panels and wall jacks for termination of UTP cables.

Modular Jacks follow the 568A or 568B similar to Modular Plugs.

All parts of a Category 5 implementation must be Category 5 certified for proper operation

Optical Fiber Uses Light pulses to transmit data. Impervious to EMI (Electro-Magnetic

Interference) and RFI (Radio Frequency Interference)

Light looses signal strength much slower than electricity which is good for distance.

Fiber offers greater Bandwidth 1 pair of fiber can offer greater bandwidth than

1,400 copper pairs in a voice system. Consists of a glass core surrounded by a

protective coating.

Multi-Mode and Single Mode Fiber

Multi-Mode fiber Uses LEDs to transmit data

Offers a number of "paths" for light to traverse or travel down a cable.

Light travels down the core with a layer outside of the glass core reflecting the signal back to the core.

The number of modes is determined by the wavelength of the light source and the size of the core.

2Km max distance for multi-mode fiber.

Single Mode Fiber Single Mode Fiber

Uses a laser to transmit data (rather than an LED)

More focused single path for light to travel down.

Used in long distance high bandwidth applications