SHIELDED CABLE PERFORMANCE PARAMETERS

SHIELDED CABLE PERFORMANCE PARAMETERS
NETWORK CABLE SOLUTIONS MODULE 2-J

SCREEN TECHNOLOGY Screening of UTP cables Shielded Screened or Foiled
Known as ScTP in the Americas. Low usage Known as FTP in Europe 80% of installed LAN’s Primarily in UK, France, Germany

SCREEN TECHNOLOGY Advantages Disadvantages
Greater immunity from RFI/EMI interference. Yields lower bit error rate. Greater immunity from radiated signals. Yields a more secure cabling solution. Disadvantages Higher installed cost Material and Labor Greater difficulty in installation Shorter link lengths under certain conditions

SCREENED TECHNOLOGY Two basic construction FTP (ScTP)
Four pair cable with an overall foil shield. Drain Wire S-FTP Four pair cable with individually pairs. Overall braided shield. Similar to the STP cables used in Token Ring applications.

SCREENED TECHNOLOGY 100 ohm Shielded cabling Design
Not 100 Ohm UTP with a shield. Shielded 100 Ohm twisted pair is designed to provide certain system performance characteristics It can have a large number of variations.

STANDARDS TIA/EIA 568-A Has references to 4 pair, 100 ohm shielded cable It is allowed if it meets the same performance specifications as UTP. No description of cable construction. No specifications on the connector shield interface. No specifications on shielding performance. No guideline on how to design or install a system in order to maintain shielding performance

STANDARDS TIA Task Group Formed to fill the gaps and define specific.
Component Requirements. Installation Requirements. Task Group Definition 4 pair to be used as a standard. Overall foil shield and drain wire to be the basic construction. Other shields and braids may be added as long as basic construction is maintained.

STANDARDS TIA Task Group Task Group Definitions
Performance categories are the same as for UTP. Color coding is the same. 8 position jack is maintained. Jack to plug shield has been standardized and a test has been developed to verify shielding performance of a mated pair. Requirements for shield continuity and grounding have been determined.

STANDARDS ISO/IEC 11801 More complete than TIA EIA 568A, but has gaps.
List tentative specifications on cable and connector shielding performance. Provides basic installation guidelines on shield continuity and grounding. Allows both 2 pair and 4 pair. Allows 120 ohm impedance.

STANDARDS ISO/IEC 11801 EN 55022 Allows both:
Overall shield construction Individually Shielded Construction EN 55022 This directive defines the limits and methods of measurement of ratio frequency interference characteristics of information technology equipment. Limits on what a LAN can emit. Similar to limit imposed by the FCC in the U.S.

STANDARDS EMC & Cabling Systems
Unshielded or badly shielded cable cannot pass the European emissions directive at much more than 30 Mhz without encoding schemes or filter devices. The FCC in the United States limits the transmission frequency at 30 Mhz Through encoding schemes transmission at Mhz is possible because it spreads the energy over a wider frequency.

SHIELDING EFFECT Emissions
Screens reduce the radiated signals by a minimum of 20 dB.

STANDARDS EN 55024 Defines the degree of sensitivity of a system with regard to the following: Electrostatic Discharge Immunity, Part 2 Radiated Immunity, Part 3 Fast Transient Immunity, Part 4 Induced Interference, Part 6

POSITION Strong position in Europe.
In areas where shielded cabling is used. Reflects concerns over more stringent regulatory controls on electromagnetic emissions. Concerns regarding interference from electromagnetic noise. European Community used the term electromagnetic compatibility (EMC) to encompass both concerns.

EMC CONTROL Shielding is not the only means of EMC control.
Well balanced Non shielded twisted pair cables are effective in limiting emissions and interference at current digital transmission frequencies. Electronic techniques are used to limit transmission frequencies and maintain acceptable bit error rates in typical office environments.

EMC CONTROL UTP Cable EMC control dependent on system balance.
Balance dependent on pair twist rate. Pair twist rate is close to manufacturing minimum. Crosstalk performance dependent on variation of twist length. Ability to further improve crosstalk by twist is limited.

APPLICATION Emission Immunity
Emission standards, when tested, are for “typical” installations which is done in a controlled laboratory environment field installations may be different.. Cannot cover all installations variables. Immunity Influenced by nearby machinery and equipment sources. Influenced by nearby sources of RFI.

ADVANTAGES OF SHIELDING
Take over at point that pair twists leave off and provide electromagnetic interference control at higher frequencies. Individually shielded cables can provided additional immunity to crosstalk that is not achievable by pair twisting.

APPLICATION Shielded cables are used to augment EMC characteristics of UTP type cables. Provide additional control for critical networks. Additional immunity over eletromechanically noisy environments. Can be viewed as an additional insurance policy.

LINK LENGTH Due to the shield a thicker primary insulation is required. To meet the same attenuation and impedance specifications as that of UTP. It is impractical to make a 24 AWG patch cord so that it will fit modular jacks. In Europe a 26 AWG cord is allowed. Attenuation in a 26 AWG cord can be as much as 1.5 times higher than a 24 AWG solid cable. 24 AWG stranded is 1.2 times.

CONNECTORS The trend in the United States and most other areas is to standardize on the eight position jack. Standardized interface to most LAN equipment. Other connectors available that can utilize that of 24 AWG cable. Non standard designs.

GROUNDING Two methods of grounding are currently in use.
Star where one end of the cable is grounded. Mesh where both ends of the cable are grounded. The mesh type system may cause ground loops if both grounding points are not at the same ground potential. The star grounding configuration is recommended.

GROUND LOOPS Ground Loops if Mesh Grounding is used.
To assure that ground loops do not occur, measure the following between the shield and the green grounding conductor of the outlets servicing the work area. Resistance should be less than 3.5 ohms. Voltage should be less than 1 VRMS

PERFORMANCE TESTING Performance Testing Standards
Recently the ISO/IEC standardized the performance testing of shielded components in terms of Transfer Impedance. The TIA TSB will also standardize on this method. Prior to this manufacturers decided on the method to be used.

SUMMARY The benefits of a shielded cable system is that it will minimize the variability of installed twisted pair cabling balance and add signal to noise margin.

SHIELDED CABLE PERFORMANCE PARAMETERS
QUESTIONS?

FTP CABLE INSTALLATION
NETWORK CABLE SOLUTIONS MODULE 2-K

FTP INSTALLATION Scope
To provide the installer with the guidelines to properly handle high grade FTP cable during installation. Proper handling assures optimum cable performance for intended present and future applications.

FTP INSTALLATION Construction
Pairs are twisted more tightly and built to specific design constraints in a Cat. 5 cable. A precise twist is induced into the bundled 4-Pairs prior to jacketing. Geometry becomes critical to maintain performance. Damaging or changing the position of the pairs adversely affects the ability of the cable to carry high data rates.

FTP INSTALLATION Minimum Bend Radius
Cables exceeding the minimum bend radius will exhibit degraded performance. Returning flawed section to a larger diameter will not correct the fault. the cable will still exhibit the degraded transmission performance

FTP INSTALLATION Minimum Bend Radius Review conduit bends
Exercise care in installing cable in trays Do not bend cable over corners Do not coil cable tightly and stuff into work box. Store excess coiled in ceiling Exercise care when dressing cables

FTP INSTALLATION Minimum Bend Radius Service Loops
Sweep cables to avoid bends and kinks. Kinking the cable changes the shape of the core, moves the pairs and changes the geometry Damage is permanent Service Loops 1-3 feet loops at termination points Leave service loops along the route of the cable

FTP INSTALLATION Maximum Tensile Loading
Exceeding the maximum tensile loading will adversely affect the performance of the cable. Quality of the cable is a affected long before damage is visible Physical stress must be guarded against during installation and in suspended cable runs. Cables should be well supported. Correcting cable tension will not reverse the effect of over-loading. Maximum cable loading for an FTP four pair cable is 25 lb.

FTP INSTALLATION Over-Cinching
Over-cinching causes compression and distortion of the cable, degrading cable performance. Cable ties must never distort the jacket. Avoid using staples Never crush the cable with staples.

FTP INSTALLATION Avoid using staples because they crush the cable
The wraps should not distort the jacket of the cable A properly installed tie wrap can easily be moved up and down and twisted around the bundle

FTP INSTALLATION Over-Cinching
Select non-compression cable management accessories Velcro tie wraps “D” rings Nail on cable clamps

FTP INSTALLATION Cable Bundles
Assure that weight of bundle in not compressing cable jacket. Exert care when running a large cable bundle around a bend In trays fiber cable should be placed on the top and FTP on the bottom.

FTP INSTALLATION Cable Lengths
Horizontal runs are limited to 90 meters or less. Work area equipment cables are limited to 3 m or less. Patch cords, jumpers, and cross connects are limited to 7 m or less in the telecommunications closet.

FTP INSTALLATION Other Installation Suggestions
Do not share bore holes with power wires. Never install components of unknown or questionable manufacture or quality. Keep wire away from heat sources, heat ducts and pipes. Leave one to three foot service loops at outlets and connection points. When existing a cable tray it is recommended that a service loop is left. Use proper support methods when installing a cable in a dropped ceiling.

FTP INSTALLATION Cable Installation
Each horizontal run should be a continuous link to a single work area. Bridging of horizontal runs is not acceptable. Do not split pairs between multiple outlets. All four pairs must be connected to a single jack or connector.

FTP CABLE INSTALLATION
QUESTIONS?

NETWORK CABLE SOLUTIONS MODULE 2-L
FTP CABLE TERMINATION NETWORK CABLE SOLUTIONS MODULE 2-L

FTP TERMINATION Termination of FTP cable from UTP differs in that:
Shield continuity must be maintained throughout the system. Shield must be grounded.

FTP TERMINATION Termination Procedures
Strip cable to expose conductors, drain wire and foil. Cut foil even with outer jacket. Slip cable over grounding tab. Be sure that the tab is on the inside of the foil shield. Bend drain wire ground tabs against the cable. Wrap the drain wire around the tabs and the cable. Apply tie wrap to assure good contact of drain wire to grounding tab. Punch pairs down. Snap metal shield over connector.

FTP CABLE TERMINATION QUESTIONS?

LAN CABLING SYSTEMS OVERVIEW
NETWORK CABLE SOLUTIONS MODULE 3-A

LOCAL AREA NETWORK A Local Area Network or LAN is a system that interconnects data devices to share information at high speeds in a limited geographic area. Accomplished with a combination of hardware and software.

LAN CABLING LAN cabling provides a path to distribute data signals
The objective of the cabling systems is to be reliable and error free Could be the most expensive component of a LAN. May restrict technology. Important element in high speed LAN’s

NETWORK CABLING FACT 70% of all LAN problems are directly related to the media. 90% of all LAN problems are directly related to the media and physical hardware.

CABLING FACTS Why you should assure only the best cabling system is installed in your facility.

LIFE CYCLES Software - 1 Year PC and Micros - 5 Years
Mainframe years Cabling System years Building Shell years

NETWORK INVESTMENT Software - 54% Intelligent Workstations - 34%
LAN Equipment - 7% Cabling %

DOWNTIME 70% of all downtime is cable related.
Downtime costs run between $1000 to $50,000 per hour

SPEED FOR DATA Past Current Near Future
1.2 kbps. 9.6 kbps kbps. 4 Mbps. Current 10 Mbps. 16 Mbps. 100 Mbps. 155 Mbps. 1 Gbps. Near Future 10Gbps, 40Gbps

PAST PRACTICES Cabling usually was an afterthought
Most cabling systems were system specific. Objective was to spend as little as possible. Little was known regarding cable technology on the part of decision makers.

CABLING DESIGN CONSIDERATION
What is the current network speed. Over what distances will the data be transmitted. Applicable LAN standards. What are the applicable fire codes. What applications will the cable plant need to support in the future.

LAN CABLE CHOICES Coaxial cable (Coax) Shielded twisted pair (STP)
Unshielded twisted pair (UTP) Fiber optic cable

COAXIAL CABLES Construction High Bandwidth Several types Ethernet LANs
single conductor Thick dielectric Braided shield High Bandwidth Several types Ethernet LANs

COAX TERMINATION Connector types used on coax Thicknet/N type
Thinner or IBM 3270/BNC type Video/F type

SHIELDED TWISTED PAIR CABLE
Two types IBM type cable 150 ohm Each pair individually shielded Overall braided shield ScTP or Foiled 100 ohm Pairs not individually shielded Overall foil shield

High Bandwidth Token Ring 150 Ohm STP cables based on IBM cable types

STP TERMINATION connector types used on STP STP Data connector
Self shorting

UNSHIELDED TWISTED PAIR CABLE
Construction Two to four individually twisted pairs EIA/TIA-568 A specifies four pair Cables up to 25 pair available No shield 24 AWG solid conductor Stranded conductor for patch cords Small in size Performance defined to 100 MHz

Five categories of UTP cable. Category designation indicates cables performance In today’s LANs only Category 3 and Category 5 are used and the Category 5 enhanced

UTP TERMINATION Connectors used in UTP termination
8 position RJ-45 type modular plug used to terminate cables 8 position modular jack Used to terminate cables at wall plate Punch down blocks Used to terminate cables in closets 66 blocks 110 blocks

UTP TERMINATION

FIBER OPTIC CABLE Two optical fibers need for a LAN circuit
Several types of coatings and jacketing Tight buffer Loose tube gel filled Multipurpose indoor/outdoor Bandwidth is unlimited.

FIBER OPTIC CABLE

FIBER OPTIC CABLE Developed to meet bandwidth hungry applications
Transmits any type of signal voice, video, data analog or digital Future unlimited Current limitations due to electronics

FIBER OPTIC TERMINATION
Fiber optic cable termination on both ends with a connector Connectors joined by barrel connector Many types of connectors on the market currently ST type most popular SC is recommended standard in TIA/EIA-568A

FIBER OPTIC TERMINATION

LAN TOPOLOGIES Bus Ethernet Ring Token Ring Star TIA/EIA-568A

BUS TOPOLOGY Advantages Disadvantages Low cable usage
Simplified cable management Disadvantages Design Complexity Preplanning is a requirement Cable failure will bring down the network

RING TOPOLOGY Advantages Disadvantages Low cable usage
Simplified cable management Disadvantages Design Complexity Preplanning is a requirement Difficult servicing the media Multiple potential failure points

STAR TOPOLOGY Advantages Disadvantages Easy to design
Minimal preplanning required Simplified servicing and maintenance Increased Network reliability Disadvantages Higher cable usage Central point of failure

NETWORK COMPONENTS & CABLES
Equipment Room Main Distribution Frame Telecommunications Closet Patch Panel Cross-Connect Block (“66”, “110”) Hub (MAU) Gateway Router, Bridge

LAN CABLING SYSTEMS OVERVIEW
QUESTIONS?

NETWORK CABLE SOLUTIONS MODULE 3-B
LAN TROUBLESHOOTING NETWORK CABLE SOLUTIONS MODULE 3-B

LAN TROUBLESHOOTING If the LAN cabling is in question or has been determined to be at fault, then the following steps can be followed to determine what the specific problem is.

LAN TROUBLESHOOTING 1. Find the Cable 2. Is the cable carrying traffic
Locate and identify both ends of the cable in question. 2. Is the cable carrying traffic With your test equipment check the cable for noise. Readings in the frequency for the systems topology greater than 300 mV probably mean the link is active. Shut down the link.

LAN TROUBLESHOOTING 3. Noise measurement 4. Connectivity
Once the link is shut down, the noise measurement should be carried out again to check for signals from outside sources. 4. Connectivity Check pin to pin connectivity of the cable. Look for Wiring reversals Shorts or opens

LAN TROUBLESHOOTING 5. Length 6. Impedance
Next test that should be performed using a hand held tester or TDR for length. Is the length within specification. 6. Impedance Using an TDR or a hand held meter test for impedance. Ideal TDR plot is a flat line. Reflections > +/-10% should be investigated.

LAN TROUBLESHOOTING 7. Average and Impulse Noise
Using wideband AC voltmeter look at frequencies up to 100MHz for activity. Background level of 70 mV is acceptable. Narrow down the frequency to determine source. Low frequencies-AC power, lights, motors. Middle frequencies-computer switching power supplies, light dimmers, medical equipment. High frequencies-radio, television, microwave broadcasts or network traffic (NEXT).

LAN TROUBLESHOOTING 8. Attenuation 9. Near End Crosstalk
Using an injector and a power meter test the cable’s loss characteristics. Test through all patch panels and cross connects and patch cords. Be aware that some shielded cables have high capacitance and high attenuation at high network speeds. 9. Near End Crosstalk Using a hand held tester check for near end crosstalk. If these tests have negative results the cause of the LAN failure is all probability not the cable plant.

LAN TROUBLESHOOTING For fiber optic cable the procedure is much simpler. Using an OTDR determine if the length is correct and if the attenuation is within limits. Bandwidth may become an issue if it is an older cable plant. Bandwidth cannot be tested in the field with any degree of accuracy.

LAN TROUBLESHOOTING QUESTIONS?

LAN DESIGN CONSIDERATIONS
NETWORK CABLE SOLUTIONS MODULE 4-A

LAN DESIGN Standards should be considered with minimum requirements.
Different customers have different needs. Design a system that fits the customer.

LAN DESIGN Work Area Requirements Closet Requirements
Backbone Distribution Requirements Horizontal Distribution Requirements

LAN DESIGN Systems Evaluation Types of PC’s
Bandwidth hungry applications CAD Financial traders Video, Multimedia, Teleconferencing Modems or fax lines at the desk Voice systems

LAN DESIGN Network to be installed Future migration plan
10Base-T 100Base-TX ATM FDDI Future migration plan Horizontal Media UTP Fiber to the desk STP Special cables

LAN DESIGN Connectors Network Equipment T568A or B ST or SC or FDDI
Hardware selection Application specific Network Equipment Connections Installation options

LAN DESIGN Backbone Media Distribution UTP Fiber STP
Future growth requirements Distribution Horizontal Star, Bus, Ring Backbone Collapsed Backbone

LAN DESIGN Telecommunications Closets Horizontal Distribution Size
Layout Construction Horizontal Distribution Cellular floor Conduit Drop ceiling Raised floor

LAN DESIGN Horizontal and Backbone Pathways Lengths Routing
EMI sources RFI sources Fire codes

LAN DESIGN LAN Design Process Determine requirements at the work area.
Outlets Media LAN Equipment Determine requirements for telecommunication closets. Space Hardware Determine Horizontal distribution Pathways Determine Backbone Distribution

LAN DESIGN LAN Systems Two choices Standards Driven Technology Driven
Best choice because the LAN will serve the customer for a much longer period.

LAN DESIGN QUESTIONS?

WORK AREA DESIGN CONSIDERATIONS
NETWORK CABLE SOLUTIONS MODULE 4-B

WORK AREA Standards require a minimum of two cables per area.
Not necessarily in the same faceplate. Pair splitting not allowed. One UTP Other cable can be UTP STP Optical fiber

WORK AREA Jacks Eight position modular jack RJ-45 type.
Same category as the cable. Can be higher category. Link category is determined by lowest performing component. Pin assignments per T568A or T568B.

UTP/ScTP TERMINATION

UTP / ScTP TERMINATION PIN 1 2 3 4 5 6 7 8 T568A Pair 3 3 2 1 1 2 4 4
Color W-G G W-O BL W-BL O W-BR BR T568B Pair Color W-O O W-G BL W-BL G W-BR BR

UTP/ScTP TERMINATION Selection of termination options. T568A
Corresponds to international ISDN Standard. Preferred pinouts in TIA/EIA 568-A Standard. Backward compatible to USOC for pairs 1 and 2. T568B Most widely specified worldwide for data installations. Backward compatible to USOC, pair 3 corresponds to pair 2. Subset of IEEE BASE-T Note USOC is a nested configuration on that is the most commonly used for voice systems in the U.S.

WORK AREA Work Area Hardware
Must be of equal or higher category as the horizontal cable. Must be securely mounted at planned locations. Must be easily accessible. Fiber optic connectors that are approved. 2 simplex SC’s 2 simplex ST’s 568SC

WORK AREA Application Specific Components
Should not be installed as a part of the horizontal cabling. Must be outside the faceplate.

WORK AREA Cable Termination
All four pairs must be terminated to a single connector. pair splitting is not allowed. Bridged taps and splices are not allowed.

EQUIPMENT CORDS UTP/ScTP Equipment Cords
Same Category or higher as the horizontal cable. Preterminated equipment cords for a Category 5 systems should be purchased from a qualified supplier. Typically the hardware manufacturer.

EQUIPMENT CORDS Fiber Optic Equipment Cords
Same fiber type as the horizontal cabling. Must be a two fiber (duplex) cable. Labeling must indicate crossover function.

WORK AREA Multi User Assembly and Consolidation Point
Must be manageable in size. Serve 6 to 12 users. Permanently located. Work area cables clearly labeled Outlet to be marked with maximum allowable work area cable length.

WORK AREA Locating Outlets
Coordinate outlet locations with intended floor plan. Otherwise 2 outlet boxes per 100 sq ft (10 sq m). Mount outlets between 15 in and 48 in (380 to 1220 mm) above the finished floor. Unless local codes differ.

WORK AREA Unterminated Cables Exposed Cable
Stored in outlet boxes with a face plate. Face Plate label should identify the outlet box is for telecommunications use. Exposed Cable Cable installed between the telco closet and the work area outlet shall not be installed in the work area or any other space with public access.

WORK AREA Modular Furniture
Raceways closest to the floor should be used for power cable. Modular furniture with beltways is preferred. Belts above desk level are designed for telecommunications use. Under no circumstances should communications cable share a raceway with power cable without separation.

WORK AREA DESIGN CONSIDERATIONS
QUESTIONS?

TELECOMMUNICATIONS CLOSET DESIGN CONSIDERATIONS
NETWORK CABLE SOLUTIONS MODULE 4-C

TELECOMMUNICATIONS CLOSET
This is the transition point between the backbone cable and the horizontal cable. Should be dedicated to the telecommunications function. Minimum of one per floor. Additional closets if: The floor area served exceeds sq ft (1000 sq m) The horizontal distance exceeds 300 ft (90 m)

TELECOMMUNICATIONS CLOSET
Recommended closet sizing on a worker area having 100 sq ft (10 sq m) Building less than 5000 sq ft (500 sq m) can be served by a small closet with a minimum size of 2 feet by 8.5 feet (0.6m by 2.6m).

TELECOMMUNICATION CLOSETS
Location Locate closets near the geographic center of the floor space that it is intended to serve Reduces cabling distances Aids in avoiding multiple closets Minimum of one closet per floor recommended

Closets refer to one of two types of areas Main Distribution Frame (MDF) Logical center of the Star Topology Central control point for cable plant administration Hosts devices (mainframe, PBX) located nearby Intermediate Distribution Frame (IDF) Subordinate to the MDF Transition point between Backbone and Horizontal cable Control point for local cable plant administration

Requirements Minimum of two wall covered with plywood. No false ceilings. Allows for easier cable routing Access to the main building grounding electrode 36 inch by 80 inch (0.91 m x 2 m) door. Hinged to open out

Requirements Electrical Two 15 amp 120 volt isolated ground circuits. (Minimum) Two 15 amp 240 volt isolated ground circuits. (Minimum) Ideal if perimeter outlets are placed every 6 feet (1.8 meters). Lighting 50 footcandles (540 Lx) at 3 feet (90 cm) above the floor. Separation LAN cable components should not be co-located with electrical panels or high voltage equipment. Do not share with custodial or storage functions.

Requirements Temperature 64 degrees F to 75 degrees F 18 degrees C to 24 degrees C Humidity 30 to 55% relative (non-condensing) Heat Dissipation BTU/hr per cabinet

Cabling Practices Multiple types of media used in backbones should be cross connected in the same closet. Horizontal cables serving the same work areas should be terminated in the same Closet. Cables should have appropriate cable management and cable organization hardware to eliminate stress on the cables.

Terminations Horizontal and Backbone cables must be terminated on hardware meeting or exceeding the category of the cable. Routine moves and changes must not be accomplished by retermination of fixed backbone or horizontal cables. Jumpers or patch cords should be used. Application specific devices should be placed outside the Horizontal Cross-connect.

Factory Pre-terminated Patch Cords Reduces the performance variations due to field cabling practices. Should be the same category or higher than the cable plant installed. Cross Connect Jumpers, patch cords, cross-connects, connecting equipment or backbone cable with horizontal cable should not exceed 7 meters.

Equipment Rooms Should house only equipment directly related to the telecommunications system. Usually equipment that is common to several floors is housed in an equipment room. Must meet all the same requirements as a Telecommunications Closet. Minimum size 150 sq ft (14 sq m). 0.75 sq ft (0.07 sq m) per 100 sq ft (10 sq m).

Sources of EMI / RFI Telecommunications closets and equipment rooms should be located away from sources of EMI and RFI Check for Electrical power supply transformers. Motors and generators. X-ray equipment Radio and radar transmitters. Photocopy equipment. It is not only the copper cable media that is susceptible to EMI / RFI but also the LAN equipment.

Grounding and Bonding Must meet all local codes Should meet the requirements of TIA/EIA-607 Grounding points should be easily accessible in all closets.

Electrical Protection All telecommunications cables that extend outside of a building is susceptible to extraneous voltages or currents. Exceptions are all dielectric optic cables. It is recommended that Secondary Protection be installed on all cables that exit the building to protect electronic equipment.

TELECOMMUNICATIONS CLOSET DESIGN CONSIDERATIONS
QUESTIONS?

HORIZONTAL DESIGN CONSIDERATIONS
NETWORK CABLE SOLUTIONS MODULE 4-D

HORIZONTAL Considerations
Cable plant should facilitate ongoing adds, moves, changes, and maintenance. Should accommodate current use requirements. Should be designed to accommodate future equipment and service changes.

HORIZONTAL Standards Recognized Horizontal Media TIA / EIA 568-A
100 ohm Unshielded Twisted Pair (UTP). 150 ohm Shielded Twisted Pair (STP). 62.5/125 um duplex optical fiber cable. ISO and TIA/EIA 568-A 100 ohm Screened Twisted Pair (ScTP). a.k.a. Foil Twisted Pair (FTP)

HORIZONTAL Composite, Hybrid Cables
In horizontal applications it is acceptable to use composite or hybrid cables as long as each individual cable under the shared sheath exhibits standards compliant performance. Crosstalk requirements are more stringent than for individual cables.

HORIZONTAL UTP Advantages Low cost Simple installation
Supports most applications New applications are designed for use with UTP Disadvantages Susceptible to EMI/RFI Distance limitations

HORIZONTAL STP/ScTP/FTP Advantages Good EMI/RFI immunity Disadvantages
Difficult to install Higher installed cost Improper shield and grounding installation can result in the cable acting as an antenna

HORIZONTAL Optical Fiber Advantages Immune to EMI/RFI
Unlimited bandwidth Longer distances Supports all applications Ease in testing Disadvantages Longer installation time Highest installed cost

HORIZONTAL Topology Standards approved topology is the Star.
Each workstation has its own cable terminated at the horizontal crossconnect in the telecommunications closet.

HORIZONTAL Selection of Horizontal Media
Minimum of two telecommunications outlets must provided for each individual workstation. One outlet must be supported by a four pair 100 ohm UTP or ScTP (FTP) cable. Per the standard maximum of a Category 3 is required and a Category 5 is recommended Other outlets can be supported by any of the recognized media.

HORIZONTAL Distance Limitation
UTP cable is limited to 295 feet (90 meters) in the horizontal. Optical fiber is limited to 295 feet (90 meters) when hub equipment is located in each telecommunications closet. Optical fiber cable is limited to 984 feet (300 meters) when hub equipment is centrally located.

HORIZONTAL Distance Limitations
Length of cable referred to in the distance limitation is the jacketed length not the electrical length Two lengths vary because of pair twists Telecommunications closet’s span is considered to be a radius of 200 feet (60 meters) Horizontal cables follow pathways Slack

HORIZONTAL Service Loops
It is recommended that a service loop of between 1-3 feet of cable be left at all termination. This is to facilitate servicing those terminations.

HORIZONTAL Cabling Practices
Connecting hardware must be installed in compliance to local codes Bridged taps are not allowed UTP/ScTP (FTP) cable runs must be continuous, without splices

HORIZONTAL Multi User Assembly and Consolidation Point
Must be manageable in size Serve 6 to 12 users Permanently located Work area cables clearly labeled Outlet to be marked with maximum allowable work area cable length

HORIZONTAL Consolidation Points
Only one consolidation point allowed in a horizontal cable tun Cross-connections are not permitted at the consolidation point Active equipment is not allowed at the consolidation point. Each horizontal cable exiting the consolidation point must have all four pairs terminated in the same modular jack.

HORIZONTAL Centralized Fiber Optic Testing
Used in Fiber-To-The-Desk scenarios Horizontal runs with UTP are limited to 90m. Fiber has increased transmission distance Horizontal cables can be installed directly to centralized “Hub Farms” within the building. 300 meter maximum distance. Three accepted methods Pull through Through Splice Through Connect

HORIZONTAL EMI/RFI Cable routing, closet placement and drop locations should be such as to avoid sources of EMI and RFI sources. Detailed in standard EIA/TIA-569.

HORIZONTAL DISTRIBUTION
Conduit Types Recognized: Electrical metallic tubing Rigid metal conduit Rigid PVC Conduit Type Not Recommended Metal Flex Conduit Cable suffers from abrasion

Installation Guidelines Maximum run length without pull point 30 meters (100 feet) Maximum of two 90 degrees bends between pull boxes or pull points Fish tape or pull cord shall be placed in installed conduit

Installation Guidelines Conduits protruding through the floor should protrude in a Telco Closet should extend 1 to 4 inches ( mm) above the finished floor Conduits protruding through the floor in other areas should extend to 1 to 2 inches (25-50 mm) above the finished floor

Installation Guidelines Single conduit run extending from a telecommunications closet shall not serve more than three outlets Conduits shall be reamed Conduit shall be terminated with an insulated bushing

Ceiling Pathways Ceiling distribution pathways be fully accessible Drywall or plaster ceiling are not allowed Minimum of 3 inches (75 mm) is needed between cable support hardware and the false ceiling. Same Distance is required between the hardware and the structural ceiling.

SEPARATION Pathway Separation
Closed metal pathways provide adequate protection from capacitively coupled (rapid changes in high voltages) in commercial buildings. Closed metal pathways of ferrous induction suppression material shall be used in areas of high inductively coupled noise (rapid changes in high current). Open or non-metal pathways shall be placed with sufficient separation.

SEPARATION

SEPARATION High Voltage Separation
Telecommunications cables should have a separation of 10 feet (3 meters) from panels and power carrying voltages of 480 Vrms or greater.

HORIZONTAL Firestopping
Properly rated firestop systems must be installed to prevent or retard the spread of smoke, water, fire and gases through the building.

HORIZONTAL DESIGN CONSIDERATIONS
QUESTIONS?

BACKBONE DESIGN CONSIDERATIONS
NETWORK CABLE SOLUTIONS MODULE 4-E

BACKBONE Backbone Planning
Backbone cable plants should be designed to accommodate the systems that are currently being used as well as those that will be in use in the future. Planning should consider the changes that are anticipated in service requirements and system growth for a period of not less than 3 years and ideally up to 10 years. Other factors that must be considered when a Backbone Cable Plant is being designed are: Bandwidth requirements for present and future applications. The number of Work Areas that are served by the backbone segment.

BACKBONE Topology The backbone cabling plant must use the hierarchical star topology. Two hierarchical levels of cross connects are allowed in backbone cabling. Between the horizontal cross connect and the Main cross connect only one cross connect may exist. No more than three cross connects between any two horizontal cross connects. Limitation of two levels in hierarchy limits the size of LAN. In large installations (I.e. universities, military bases) the area should be segmented into smaller components and then interconnected.

BACKBONE Location Main and intermediate cross connects are to be located in Telecommunications Closets, Equipment Rooms, or Entrance Facilities. Main cross connects Ideally located in an equipment room Ideally located in the geographic center of the area it serves.

BACKBONE Recognized Backbone Cable Types
100 ohm UTP/ScTP four pair cable. 100 ohm UTP multipair cable. 150 ohm STP cable. 62.5/125 or multimode optical fiber cable. Singlemode optical fiber cable.

BACKBONE Composite and Hybrid Cables
In backbone applications it is acceptable to use composite or hybrid cables as long as each individual cable under the shared sheath exhibits standards compliant performance. Crosstalk requirements are more stringent than for individual cables.

BACKBONE Media Selection
UTP and/or ScTP cables may be used in backbone cable segments that do not exceed 295 feet (90 meters) for Category 5 applications. Segments that are in excess of 295 feet (90 meters) should utilize optical fiber cables.

BACKBONE Media Selection Fiber Optic Cable
The selection of fiber optic cable assures that high speed data applications will be supported in the backbone. Fiber optic cable also has higher bandwidth in less pathway space than copper media. Fiber optic cable is immune to the effects of RFI and EMI. All dielectric fiber optic cables are immune to ground loops.

BACKBONE Growth Recommendation is that one fiber pair be provided for each current application and a 100% growth factor to be added to the fiber count.

BACKBONE Distance Limitations
It is important to note that not all current applications will operate properly over lengths allowed by the standards for the copper media. The standards allowed UTP cable lengths are based on voice applications. Backbone cable cannot exceed 295 ft (90 m) for applications with bandwidths equal to or greater than 4 MHz.

BACKBONE Patch Cords In applications where bandwidths are less than 4 MHz, patch cords and jumpers in the Main Cross connect and Intermediate Cross connect shall be less than or equal to 66 ft (20 m). In applications where bandwidths are equal to or greater than 4 MHz, the patch cords and jumpers are limited to 16 ft (5m).

BACKBONE Planning If requirements are unknown, plan for one copper pair for every 100 sg ft (10 sq m) If requirements are known, plan for copper pairs for each 2 pair application and 8 pairs for each 4 pair application Provision for growth and back up Provide 4 fibers for each 2 fiber application

BACKBONE Service Loops
Backbone cables terminating at a Horizontal cross connect should have a 10 feet (3 meter) service loop Backbone cables terminating at the main cross connect or at intermediate cross connects should have at least 33 feet (10 meters) service loops

BACKBONE Design considerations discussed in the Horizontal Section
EMI/RFI Separation Pathways Firestopping

BACKBONE DESIGN CONSIDERATIONS
QUESTIONS?

THANK YOU

SHIELDED CABLE PERFORMANCE PARAMETERS

Similar presentations

Presentation on theme: "SHIELDED CABLE PERFORMANCE PARAMETERS"— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

SHIELDED CABLE PERFORMANCE PARAMETERS

Similar presentations

Presentation on theme: "SHIELDED CABLE PERFORMANCE PARAMETERS"— Presentation transcript:

Similar presentations

About project

Feedback