TDMM Chapter 6 Flashcards
AWG
American Wire Gauge
Balanced Twisted-Pair
Multi conductor communications cable composed of two or more copper conductors twisted in a manner designed to cancel electrical interference
Bandwidth
A range of frequencies available for signaling in Hz
Cable
An assembly of one or more insulated conductors or fibers within an enveloping sheath
Cable Assembly
a cable that has connectors installed on one or both ends
Capacitance
- ability of an electronic component to store electrical energy
- the opposition to a change in voltage
Chromatic Dispersion
A result of the phenomenon that the velocity of propagation in a medium is frequency dependent, which causes the frequency components of a pulse to lose phase coherence as it propagates
Coaxial Cable
a cable consisting of a central metallic inner conductor separated from an enclosing outer conductor by a dielectric material
Conductance
The measure of the ease with which electrical current flows through a conductor
Connector
a mechanical device used to provide a means for aligning, attaching and achieving continuity between conductors
Crosstalk
The unwanted transfer of signal from one or more circuits to other circuits as a result of EMI
Delay Skew
The difference in propagation delay between any two pairs within the same sheath
Dispersion
the loss of a signal resulting from the scattering of light pulses as they are transmitted through a medium
EMI
Electromagnetic Interference
Radiated or conducted electromagnetic energy that has an undesirable effect on electronic equipment or signal transmissions
Inductance
- the property of an electrical force field built around a conductor when current flows through it
- the resistance to change in current
Inside Plant (ISP)
Infrastructure systems inside a building
Modal Dispersion
a characteristic of transmission in an optical fiber that results from different lengths of the light paths taken by many modes of light as they travel down the receiver from source to receiver
NVP
Nominal Velocity of Propagation
The coefficient used to determine the speed of transmission along a cable relative to the speed of light in a vacuum, typically a percentage.
OTDR
Optical Time Domain Reflectometer
An instrument that measures transmission characteristics of optical fiber by measuring backscatter and reflection of injected light as a function of time. Used to measure attenuation
Optical Fiber
A transmission media using glass or plastic to transport pulse light signals
OSP
Outside Plant
Infrastructure designed for use outside
Plenum
The areas throughout the building to which one or more air ducts are connected forming part of the air distribution system
Resistance
A measure of opposition a material offers to the flow of direct current. Measured in ohms
Riser
Any vertical service ducts and the interfloor passages of the building subject to the cable installation
What are the components of a cabling system?
cables, equipment cords, patch cables and connecting hardware components
what is the difference between an equipment cord and a patch cord?
- equipment cords connect directly to active equipment
- patch cords are used to cross connect
name two general environmental styles of balanced twisted pair and optical fiber cabling
- outside plant (OSP)
- premises (ISP)
what term does ISO/IEC use to describe channel and link performance?
Class
what term does ISO/IEC use to describe connecting hardware performance?
Category
what term does TIA use to describe performance levels for cabling and cabling components?
Category
what is the minimum acceptable performance level for network cabling?
category 5e/class d
what does BICSI recommend as the minimum performance level for horizontal twisted pair?
category 6a/class e
per TIA standards what is the maximum frequency at which category 3 cable can operate?
16 MHz
per TIA standards, what is the maximum frequency at which category 3 cable can operate?
16 Mhz
per TIA standards, what is the maximum frequency at which category 5e cable can operate
100 MHz
per TIA standards, what is the maximum frequency at which category 6 cable can operate
250 MHz
per TIA standards, what is the maximum frequency at which category 6A cable can operate
500 MHz
per TIA standards, what is the maximum frequency at which category 7/class f cable can operate
600 MHz
per TIA standards, what is the maximum frequency at which category 7A/class FA cable can operate
1000 MHz
per TIA standards, what is the maximum frequency at which category 8.1/class I cable can operate
2000 MHz
per TIA standards, what is the maximum frequency at which category 8.2/class II cable can operate
2000 MHz
ISO/IEC uses an x/y designation to describe balanced twisted pair cables. What do the letters represent?
x = overall screen type
y = individual pair screen type
True or False
the ANSI/TIA standards provide clear cable design designations
False
What are the two most frequently used ANSI/TIA cable designations?
- UTP
- ScTP
True or False
Cable designations can be applied to connecting hardware in the same manner as cable
False
How should connecting hardware be referenced in general?
As unscreened or screened. UTP, STP or FTP may be appropriate as well
What is the characteristic impedance of balanced twisted pair cable?
100 ohms (+- 15 ohms)
What conductor sizes are used for balanced twisted pair cable?
22 to 26 awg
Name three components found in all balanced twisted pair cabling
- Solid or stranded conductors
- Thermoplastic insulation
- Outer jacket or sheath
How is efficient insulation defined?
As material where any loss of the transmitted signal because of loss associated with the insulation is minimal
Name two factors that affect the mutual capacitance of a balanced twisted pair cable
- The conductors insulating material
- The insulations thickness
What does permittivity indicate?
Insulations ability to transmit (or permit) an electric field
Name the four primary parameters that control the transmission performance of a cable
- Resistance (R)
- Conductance (G)
- Inductance (L)
- Capacitance (C)
Name the six secondary parameters that affect the transmission performance of a cable
- Insertion Loss
- Crosstalk loss
- Return loss (RL)
- Propagation delay
- Propagation delay skew
- Nominal velocity of propagation (NVP)
Name four mechanical characteristics that may influence transmission performance
- Tensile strength
- Temperature rating
- Flammability rating
- Environmental impact resistance
True of False
Screened cables radiate less electromagnetic energy than unscreened cables
True
Name two common styles of screening used in balanced twisted pair cables
- Foil
- Braid
Name three functions performed by a cable screen/shield
- Reduces the level of the signal radiated from the cable
- Minimizes the effecte of external EMI on the cable pairs
- Provides physical protection
Name three factors that determine a screens effectiveness
- Material type
- Thickness
- Relative coverage
What type of electromagnetic field is typically blocked by foil?
Higher frequency (30 MHz and higher)
What type of electromagnetic field is effectively blocked by copper braid?
Lower frequency (below 30 MHz)
What type of electromagnetic field is effectively blocked by solid metal tubing blocks?
Almost any electromagnetic fields
What is the purpose of a drain wire?
To drain the current induced on the screen
What type of screen provides the highest level of protection in an environment with unusually strong effects from relatively low frequency EMI?
A combination of braid and foil screens provides the highest level of protection
What is the only type of screen that is effective at very low frequencies (less than 1 KHz)?
thick wall metal conduit
What type of screen is a better choice in an environment with unusually strong effects from relatively high frequency EMI?
Foil screen
True or False
Multipair screened cabling is recognized for use in horizontal and backbone cabling applications.
False
Multipair screened cabling is recognized for use in backbone cabling applications only
Why do balanced twisted pair patch cords typically have stranded conductors?
For added flexibility
Balanced twisted pair patch cords that are stranded may exhibit __ percent to __ percent more attenuation than solid conductors
20 to 50 percent
What types of connectors are typically used on the ends of balanced twisted pair patch cords?
8 position, 8 contact (8P8C)
What term is used to describe cords that directly attach to equipment on one or both ends?
Equipment cord
What term is used to describe cords that attach one set of connecting hardware to another set of connecting hardware to form a cross connection?
Patch cord
Which type of patch cord, solid or stranded, typically features better insertion loss characteristics?
Solid
Which type of patch cord, solid or stranded conductor typically features better flex life characteristics?
Stranded
What is the primary difference between twisted pair and optical fiber cables?
Optical fiber uses pulses of light to transmit signals whereas balanced twisted pair uses an electron flow
Name the two classifications of optical fiber cable
- Singlemode
- Multimode
What is the core diameter of a singlemode fiber?
8 to 11 um
What is the approximate cladding diameter of a singlemode fiber?
125 um
What are the common core diameters for multimode fibers?
50um to 62.5um
What is the approximate cladding diameter of a multimode fiber?
125um
What three classification terms are used to describe an optical fiber cable?
- Indoor/outdoor optical fiber cable
- Indoor optical fiber cable
- Outdoor optical fiber cable
What is the recommended use for 62.5um core fiber cable?
For extensions to existing installations only
What common wavelengths are supported by multimode optical fiber cable?
- 850 nm VCSEL
- 1300 nm LED
What is the maximum distance for running singlemode optical fiber cable in structured cabling systems?
3000m (9840ft)
What type of light source is typically used with singlemode optical fiber cable?
A laser light source
What common wavelengths are supported by singlemode optical fiber cable?
- 1310 nm
- 1490 nm
- 1550 nm
- 1625 nm
Name the three causes of attenuation in optical fiber cable
- Glass materials, impurities and point efects
- Macrobends and microbe ds in the fiber strands
- Nuclear radiation (point defects) (only in rare cases)
Optical fiber attenuation is ___ proportional to length
Optical fiber attenuation is directly proportional to length
What does the modal bandwidth of multimode optical fiber provide?
A measure of the amount of information an optical fiber is capable of transporting
How is the modal bandwidth of multimode optical fiber defined?
As the frequency at which the light pulse amplitude drops 3dB at an 1km (0.625mi) distance
How will increasing the length affect the information carrying capacity of an optical fiber cable?
Increasing cable length will lower the information carrying capacity of the optical fiber cable
Name the two components that are used to determine overall bandwidth
- Modal dispersion
- Chromatic dispersion
From a practical point of view, how is the bandwidth of singlemode optical fiber described?
As unlimited
Where is loose tube optical fiber cable primarily used?
Outdoors
What is the most common diameter for a loose tube optical fiber cable?
250um
What are the two main functions of a cable jacket on an optical fiber cable?
- Physical protection
- Environmental protection
Name three advantages of loose tube optical fiber cable compared to tight buffered cables with the same number of strands
- Greater tensile strength and more robust outer jacket
- Greater resistance to low temperature effects on attenuation
- Cable jacket that expands and contracts with changes in temperature without affecting the optical fiber
Where is tight buffered optical fiber cable primarily used?
Inside buildings
What is the most common diameter for tight buffered optical fiber cables?
900um
How does a tight buffered cable protect the optical fiber?
By supporting each strand of glass with a buffer coating extruded of the base optical fibers 250um acrylate coating
name the three predominate types of coaxial cable
- Series 6
- Series 11
- RG 59
What is the characteristic impedance of series 6 coaxial cable?
75 ohms
True or False
The metallic covering on a coaxial conductor acts as a screen
False
What type of conductor does a series 6 coaxial cable have?
Solid center conductor
What types of connectors are used with Series 6 coaxial cable?
- F Style connector
- BNC connector
What type of coaxial cable is used in video backbone applications?
Series 11U
Why is Series 11U coaxial cable preferred for longer runs?
Lower attenuation than Series 6
What is the characteristic impedance of Series 11U coaxial cable?
75 ohms
What type of conductor does a Series 11 U coaxial cable have?
18 AWG stranded center conductor
What type of connectors are used with Series 11U coaxial cable?
- F Style connectors
- N Style connectors
The longer the cable length, the __ the attenuation
greater
How does the outside diameter of a coaxial cable affect attenuation?
For a given diameter, the larger the cables outside diameter the lower the attenuation
What factor determines how often signal needs to be amplified in the network?
Attenuation
True or False
A coaxial cable may be selected by simply identifying the physical size (series)
False
What designation is currently used for coaxial cables used in broadband applications?
Series X
Name six factors the ICT designer should consider when designing a broadband distribution system
- Amplifier link budget
- Amplifier cascade limitation
- Environmental factors
- Drop length
- Minimum levels of the signal to the house
- Price
What term is applied to define the areas throughout the building, compartment or chamber to which one or more air ducts are connected, forming part of the air distribution system?
Plenum
Why are plenum areas the most dangerous in terms of fire safety?
They facilitate fast distribution of flame and smoke through the building
What term refers to any vertical ducts and interfloor passages of the building subject to the cable installation?
Riser
What locations are listed as suitable for CMP cables?
Ducts, plenums and other air spaces
Why are CMR cables required to have fire resistant qualities?
To prevent the carrying of fire from floor to floor
What locations are listed as suitable for CMX cables?
Dwellings and raceways
True of False
Type CMUC undercarpet communications wires and cables shall be listed as resistant to flame spread
True
What types of cables have and -LP designation?
Cables suitable for high density PoE applications
What locations are listed as suitable for OFNP and OFCP cables?
Ducts, plenums and other space used for environmental air
Why are OFNR and OFCR cables required to have fire resistance characteristics?
To prevent fire from spreading from floor to floor
Are OFNG and OFCG general purpose fibers required to be resistant to the spread of fires?
Yes
Name the two fire safety specifications used in Europe
- IEC 60332-1
- IEC 60332-3-24
What term describes gas tight physical contact between two conductors?
Insulation Displacement Contact (IDC)
What type of special tool is required to create an IDC connection?
Punch down tool
How is gas tight contact established in an IDC connection?
By a cold weld and elimination of the air gap between the conductor and the IDC
Name the four basic styles of IDC connectors
- 110 Style
- 66 Style
- BIX Style
- LSA Style
Name four reasons the 110 Style is the most popular IDC connector
- Compact design
- Reliability
- High transmission performance capabilities
- Relatively inexpensive to manufacture
How many termination cycles can a 110 Style IDC connector complete before its reliability degrades?
At least 200
What is the disadvantage of the 110 Style IDC connector?
It does not exist in screened versions as a stand alone connector
Why has the 66 block, one of the oldest industry connectors, remained an alternative?
High density termination design, inexpensive to manufacture
True or False
It is possible to terminate more than one conductor in the same 66 contact
True, but it is not recommended
Name four disadvantages of the 66 Style IDC connector
- Does not exist in screened versions as a stand alone connector
- Covers a comparatively narrow range of transmission performance categories
- Can existing only in the form of a 66 style block
- Has a limited number of applications
Name four applications supported by the 66 style connector
- Demarcation point connecting hardware
- Platform for circuit protection
- Compact cross connections and interconnections in voice and data applications
- Metal conductor splicing
How many termination cycles can a BIX style IDC connector complete before its reliability degrades?
At least 200
Name three disadvantages of the BIX style connector
- Not widely used in the industry
- Conductor termination is performed with a special tool
- Nonexistant in screened versions as a standalone connector
Name three reasons the LSA Style connector is a popular choice for voice and data networks
- Unique quality
- Transmission performance capabilities
- Ultimate termination density
Name three disadvantages of an LSA Style connector
- Comparatively complex and expensive design
- Conductor termination is performed by a special tool
- Not widely used by the industry
Name the two parts of a modular connector
- Plug (male)
- Jack (female)
Where are 4P4C modular connectors primarily used?
Telephone handset cords
Where are 6P4C and 6P6C modular connectors used?
Telephone and modem cords
Where are 8P8C modular connectors used?
Data communication lines and patch cords
How many mating cycles is a PL 1 modular connector rated to withstand?
750 mating cycles
How many mating cycles is a PL 2 modular connector rated to withstand?
2500 mating cycles
What is a modular plug?
A male telecommunications connector for cables or cords
What does the number of positions indicate about a modular plug?
The connectors width
What does the number of contacts installed into the available positions indicated about a modular plug?
The maximum number of conductors the connector can terminate
Name two disadvantages of a modular plug
- Design limited transmission performance
- Mechanical contact results in a limited lifecycle
What is a modular plugs typical application?
Equipment cords and patch cords
What is a modular jack?
Femal communications outlet
Name the three types of eight position pin/pair assignments used with modular jacks
- T568A
- T568B
- USOC-8
Name five advantages of modular jacks
- Most commonly used
- Highest density jack design
- Inexpensive and easy to manufacture
- Wide variety of configurations
- High transmission performance
Name two disadvantages of modular jacks
- Design limited transmission performance
- Mechanical contact reduces lifecycle
Name four applications for modular jacks
- Work area telecom outlets
- Patch panel connectors
- Pre wired connecting blocks
- Active equipment input and output
What type of connector is the key system telephone connector
50 position miniature ribbon connectors
What type of special tool is needed to terminate 50 position miniature ribbon connectors?
Butterfly tool
True or False
The 50 position miniature ribbon connectors are standardized by structured cabling standards
False
What transmission performance categories are available for 50 position miniature connectors?
Category 3, 5 and 5e
Name the five basic types of connecting hardware used with balanced twisted pair cabling systems
- Telecom outlets
- Patch panels
- Connecting blocks
- Cable assemblies
- Splices
What type of hardware serves as the end point of the horizontal cabling?
balanced twisted pair outlets/connectors
Name the three main elements of a telecom outlet/connector assembly
- Mounting box
- Mounting faceplate
- Connector
What is an outlet module
A telecom jack installed into the connecting hardware housing
What is the purpose of balanced twisted pair outlets/connectors?
To connect active equipment to the cabling at work areas
What is a patch panel?
An administrative point in the cabling where the cable is terminated to connecting hardware mounted in a panel assembly that accepts patch cords
What is the main purpose of a patch panel as connecting hardware?
To provide high density, durable, accessible and reliable connection
Name three factors that determine a patch panels design
- Mounting method
- Style of connector module
- Transmission medium style
What design detail is common to all styles of patch panels?
A steel front panel that serves as a support for internal circuitry and a mounting base for connectors
How many connections are available in a high density patch panel?
48 per 1 RMU
How is cable strain relief accomplished in a patch panel?
Tie wraps or a cable management bar
Name four typical applications of patch panels
- Interconnection connecting hardware in telecom spaces
- Cross connecting hardware in telecom spaces
- Multiuser telecom outlet assemblies
- CP and HCP connecting hardware
What is the maximum category of transmission performance that can be supported by a 66 style block?
Category 5e
How are cross connects created on 66 style blocks?
With bridging clips or cross connect jumpers
Name the three parts of a 66 style connecting block
- Base equipped with two mounting tabs
- Contact holding body frame with two fanning strips
- 66 style contacts
What is an optional component of a 110 style connecting block
Standoff Legs
Does the 110 style wiring block contain an IDC?
No, its integral to the connecting block
What special tool is needed to terminate on a 110 block?
Single position or multipair punchdown tool
What pair increments are available for BIX style connecting blocks?
- 50
- 250
- 300
- 900
Name the four basic LSA style block configurations
- Disconnect modules
- Connect modules
- Switching modules
- Feed through modules
What pair increments are available for LSA style connecting blocks?
- 8
- 10
- 20
What is the purpose of an LSA style connect module
To provide a continuous link between the cable and the cross connect wiring
What is the purpose of an LSA style disconnect module?
To allow temporary or permanent disconnect of the circuit
What is the purpose of an LSA style switching module?
To allow for high density termination and patch cables
What is the purpose of an LSA style feed through module?
To provide a continuous link between the feeder and the jumper for high density terminations in small areas
What does hybrid mean when applied to equipment cords and patch cords?
That the cords have dissimilar connectors on each end of the assembly
What correction factor is used to determine insertion loss parameters for cable assemblies with 24AWG conductors?
1.2 (20 percent) to 1.5 (50 percent)
What correction factor is used to determine insertion loss parameters for cable assemblies with 26AWG conductors?
1.5 (50 percent)
Name two advantages of a cable assembly
- Compact and inexpensive device for interconnections and cross connections
- Available in multiple configurations and transmission performance levels and categories
Name three typical applications of a cable assembly
- Cross connections in data and analog transmission systems
- Interconnections in data and analog transmission systems
- Connections to test instruments
What is a balanced twisted pair splice?
A device that permanently joins conductors
How many conductors can be terminated by a single pair splice connector?
two to three
How many cable pairs can be spliced with a multipair splicing module?
Up to 25 pairs
Name three advantages of a balanced twisted pair splice?
- Widely used in OSP and premises cabling
- Provides a cost effective method of connecting
- Can be used in a wide range of applications
Name two typical applications for a balanced twisted pair splice
- Connectorization applications
- Cabling plant applications
True or False
Optical fiber connectors and adapters are generally not specified by cabling industry standards
True
Name the three common types of optical fiber interfaces
- LC Connector
- SC Connector
- ST Compatible
What can be used to convert a simplex LC connector to duplex?
A clip
Who establishes the bandwidth and return loss of an optical fiber cable?
Manufacturer
What is the only transmission characteristic that can easily, reliably and repeatedly be measured in the field with handheld devices?
Attenuation
What type of device is recommended for all pass/fail determination of optical loss budgets?
Power meter and light source
How does the size of an LC Style connector compare to the size of an SC Style connector?
an LC connector is half the size of an SC connector
What is the disadvantage of the SC Style optical fiber connector?
It does not feature an SFF design
What prevents an ST Style connector from rotating?
A key
Name the two primary splicing methods for optical fiber
- Mechanical
- Fusion
Name two benefits of fusion splicing compared with mechanical splicing
- Reduced loss (attenuation)
- Reduced reflectance
What is the minimum return loss for spliced multimode fiber?
20 dB
What is the minimum return loss for spliced singlemode fiber?
35 dB
Where is optical fiber pigtail splicing commonly used?
In premises cabling environments
Name the two application areas for optical fiber patch panels
- Rack mounted
- Wall mounted
Name three factors that are used to determine the style of optical fiber splicing hardware
- Mounting requirements
- Optical fiber strand count
- Splicing method
What is the splice insertion loss allowance for network cabling standards?
0.3 dB per splice
Name the two reasons that optical fiber splicing hardware is typically used
- To join two discrete optical fibers as part of a system design and installation
- To repair a break in one or more damaged optical fibers
Name three popular styles of coaxial connectors
- BNC Style connector
- F Style connector
- N Style connector
Why should screw on and hex connectors be avoided in commercial installations
They should be avoided because of performance and difficult to troubleshoot
What type of connector is recommended to ensure data transfer
Captive pin connector
What is the standard connector for use on RG59, Series 6 and Series 11 cables?
F Style connector
Why are BNC connectors the most common coaxial cable connector?
Because of their reliability and ruggedness
Name the three elements of a typical BNC Style connector
- Ferrule
- Connector Body
- Silver or gold plated center pin
Where are 50 ohm BNC connectors used most often?
In the audiovisual industry as a connector for RF antenna signals
Which type of BNC connector is most common?
75 ohm
Name the three BNC Style connector designs used in data network applications
- T Connector
- Barrel Connectors
- Terminators
Name the three versions of the BNC style connector (from a connectorization point of view)
- Crimp
- Three Piece
- Screw on (not recommended)
Typically, a 50 ohm connector is specified for use at frequencies up to __ GHz
4 GHz
Typically a 75 ohm connector is specified for use at frequencies up to __ GHz
2 GHz
What is the disadvantage of a BNC Style connector?
Field installation requires special tools
What is the most widely used style of coaxial connector for residential cable service?
F Style
True of False
F Style connectors can be used with cables that have a stranded center connector
False
Why are one piece F Style connectors gaining favor?
Higher bandwidth capabilities for satellite and broadband cable installations
What acts as the center pin for an F Style connector?
The cables solid center conductor
F Style connectors have 75 ohm impedance match up to __ GHz
1 GHz
Name two disadvantages of the F Style connector
- Less reliable than the BNC Style connector
- Field installation of some constructions require special tools
Name two typical applications of the F Style connector
- Video transmission and distribution systems
- Antenna systems
Name the three designs of N Style connectors that are used for data network applications
- Male connectors
- Barrel connectors
- Terminators
What bandwidth do N Style connectors support
11 GHz to 18 GHz
Name three advantages of an N Style connector
- Highest bandwidth
- Easy to use
- Reliable
Name three disadvantages of the N Style connector
- Field installation requires special tools
- Narrow range of different design options
- Not widely used in analog and digital transmission systems
Name five typical applications for N Style connectors
- Land mobile systems
- Wireless data transmission systems
- Paging and cellular systems
- Cable TV headend systems
- Antenna systems
Name the three basic types of coaxial connecting hardware
- Telecom outlets/connectors
- Patch panels
- Cable assemblies
Name the three elements of a coaxial outlet
- Mounting box
- Mounting plate or faceplate
- Connector