TDMM Chapter 5 Flashcards
Access Point (AP)
Standalone hardware device that acts as a wireless communications device
ADA
Americans with Disabilities Act
AHJ
Authority having Jurisdiction
Alternating Current (AC)
A current flow that alternates periodically (usually sinusoidal) in magnitude and direction
CP
Consolidation Point
An interconnection point within the horizontal cabling system
EF
Entrance Facility
EMI
Electromagnetic Interference
ER
Equipment Room
HC (FD)
Horizontal Cross Connect (Floor Distributor)
A group of connectors (patch panel) that allows horizontal, backbone and equipment cabling to be cross connected
IC (BD)
Intermediate Cross Connect (Building Distributor)
The connection point between the MC (CD) and the HC (FD)
MC (CD)
Main Cross Connect (Campus Distributor)
The cross connect that allows for interconnection of entrance cable, first level backbone and equipment cables
MUTOA
Multiuser Telecommunications Assembly
Wall jacks where computers plug in
PON
Passive Optical Network
A point to multipoint network in which unpowered optical splitters are used to enable a single optical fiber strand to serve multiple end points
TE
Telecommunications Enclosure
Telecommunications Outlet Box
A housing used to hold telecom outlets/connectors
Telecommunications Outlet/Connector
A connecting device (eg data outlet/fiber adapter) in the work area
TP
Transition Point
A location where flat undercarpet cable connects to round cable
TR
Telecommunications Room
UTC
Undercarpet Telecommunications Cable
Flat cable designed to be installed directly on the surface of a floor under carpet or tiles
VOIP
Voice over Internet Protocol
Converts voice signals to packets and transmits over a network
WLAN
Wireless Local Area Network
Name three components of a horizontal distribution system
- Horizontal Cabling
- Horizontal Pathways
- Telecom Spaces
True or False
The use of the term horizontal in the name of an element requires the element to be placed or installed parallel to the ground
False
How are horizontal pathways used?
To distribute, support and proved access to horizontal cabling
What is horizontal cabling?
The media contained within horizontal pathways
What is the purpose of a continous horizontal pathway?
To provide uninterrupted support and management of telecom cabling
What is a non continuous horizontal pathway?
The space between cable supports through which cables are placed
Name four applications that can be supported by horizontal cabling systems
- Voice Services
- Data Services
- Audio and Video
- Building Signaling
True or False
Horizontal cabling is often less accessible than backbone cabling?
True
What is the required topology for horizontal cabling?
Physical Star Topology
Name three exceptions to the requirement to use a physical star topology for horizontal cabling
- A CP or MUTOA is used to connect to open office cabling
- A TP is required to connect to under carpet cabling
- Centralized optical fiber cabling is implemented from the MC (CD) to work areas
What is the minimum configuration for a horizontal cabling system?
Two telecom outlets in the work area, one for telephony the other data
What is the transmission channel within a horizontal cabling system?
The end to end transmission path between two points at which application specific equipment is connected
Name the three elements of the transmission channel
- Permanant link cabling
- Required patch, equipment and interconnection cords
- Connection Points
What is the maximum number of connection points that are allowed in the channel model?
Maximum four connection points
name four types of connection points allowed in the channel model
- Telecom outlets or MUTOAs
- Connector of the first unit of connecting hardware at the HC (FD)
- CP Connector (optional)
- Connector of the second unit of connecting hardware at the HC (FD)
What is the permanent link?
The cabling that extends from the HC (FD) to the telecom outlet
What is the maximum number of connection points permitted in a permanent link?
No more than three
What is the maximum number of consolidation points (CPs) permitted within a permanent link?
No more than one
How does the cross connection method connect active equipment to the horizontal cabling system?
Cross connection is a method where two connecting hardware units are linked by patch cords or jumpers and used to connect active equipment to the horizontal cabling system
What term is used to describe the passive connection of cabling segments of the horizontal and backbone systems?
Cross connections
How does an interconnection connect horizontal cabling to active equipment?
the horizontal cabling is terminated on the connecting hardware (patch panel) and an equipment cord is used to interconnect the connecting hardware to the active equipment
Name the two benefits of using an interconnection vs a cross connection
- no need for a second unit of connecting hardware and patch cords
- saves rack/wall space
When are interconnections allowed in the HC (FD)
Only when the centralized optical fiber topology is used
Why are application specific devices required to be kept external to the horizontal cabling system?
facilitates use of cabling for generic network and service requirements
Why is UTC (under carpet) not recommended for use in telecom systems?
Negative aspects related to performance
What are the two components of a UTC system?
- UTC cabling
- TP where the UTC cabling connects to the horizontal cabling
What is a bridged tap?
An old method used to divide one physical comm line into several to support multiple analog subscribers
Why are bridged taps not allowed in a balanced twisted pair system?
Risk of decreased performance
If a bridged tap is required to support an analog signal in a specific area, how should it be installed?
With an adapter placed external to the permanent link work area connector
True or False
Splicing is not generally permitted within the horizontal cabling system
True
When is splicing permitted in a horizontal cabling system?
When joining fiber cabling to connecting hardware in the HC (FD)
What types of multimode optical fiber are allowed in horizontal cabling systems?
OM3, OM4, OM5
What categories of four pair balanced twisted pair cabling and corresponding connecting hardware are allowed in horizontal cabling systems?
- 5E, 6, 6A, 7, 7A, 8
What types of singlemode optical fiber are allowed in horizontal cabling systems?
- OS1a, OS2
What is the maximum permitted cable length within a permanent link?
295ft
What is the maximum permitted length for a 24AWG balanced twisted pair cord that is used within a channel but not within the permanent link?
16.5ft
What is the maximum permitted length for a 26AWG balanced twisted pair cord that is used within a channel but not within the permanent link?
13ft
What is the purpose of providing cable slack in a horizontal cabling system?
Future changes in cable system configuration
How much cable slack is recommended for twisted pair cabling that is terminated in the TR?
Enough to reach the farthest corner of the TR plus distance from floor to ceiling without exceeding 295ft
How much cable slack is recommended for optical fiber cabling terminated in the TR?
Enough to reach the farthest corner of the TR plus distance from floor to ceiling and an additional 10ft slack without exceeding 295ft
How much cable slack for twisted pair terminated in a work area?
1ft
How much cable slack for optical fiber terminated in a work area?
3.3ft
What are work areas?
Spaces in a building where occupants normally work and interact with their telecom equipment
Name four components that are typically used to accommodate the equipment in a work area
- Telecom outlet/connector
- Work area equipment cords
- MUTOAs and CPs
- WAPs
Name the two key elements of open office cabling
- MUTOA
- CP
What term describes the connecting device in the work area on which horizontal cabling terminates
Telecom outlet/connector
In most cases what type of connector is required for terminating 4 pair balanced twisted pair cabling?
8P8C type modular connector
Name the three most common multimode and singlemode optical fiber connectors
- SC
- ST
- LC
What is the minimum number of telecommunications outlets required for each work area?
One outlet with a minimum of two recognized connectors per outlet
What size telecom outlet box is required to accommodate one or two 1in conduits?
Minimum 4x4x2.25
The work area telecom outlet shall be located within ___ of an electrical outlet
3.3ft
What is the purpose of a MUTOA?
to connect more than one user to the horizontal cabling system
What is the maximum number of work areas that can be served by one MUTOA?
twelve
The use of a MUTOA cabling design option allows work area equipment cords to extend beyond ___
16.5 ft
Do not use 24 AWG work area equipment cords with lengths that exceed ___
72 ft
What is the maximum allowable length of balanced twisted pair cabling when using a MUTOA?
295ft
What is the total length of a balanced twisted pair channel when using a MUTOA?
328ft (100m)
Why should MUTOAs be installed 49ft from the HC (FD) when balanced twisted pair cabling is used?
To minimize the effects of multiple connections in close proximity on near end crosstalk loss and return loss
What is the functional difference between a CP and a MUTOA in the open office environment?
the CP introduces an additional connection for each horizontal cabling run
name four spaces where CPs can be located if permitted by codes, standards and regulations
- suspended ceilings
- access floors
- modular office furniture
- work area
how many CPs are permitted in the same horizontal cable run?
no more than one
which CP layout offers the highest degree of flexibility?
CPs located on all columns
Which CP layout offers the lowest degree of flexibility?
CPs located on columns close to the building core
how easily do CPs located in a checkerboard order accommodate change?
which type of CP layout does not accommodate changes easily?
CPs located near the building core
what type of CP layout tends to use the shortest work area equipment cords?
CPs located on all columns
What is a WLAN AP?
network device located in areas of a building or campus and placed in relatively close proximity to where users interact with their wireless devices
the HDBaseT alliance created a power over HDBaseT (PoH) standard that delivers a maximum of ___W over four pairs
95w
What are the levels of specifications for HDBaseT?
HDBaseT 1.0 and 2.0 which have the same power specifications
What is the maximum power at the source for PoE type 1?
15.40w
What is the maximum power at the source for PoE type 2?
300mA
What is the maximum power at the source for PoE type 3?
600mA
What is the maximum power at the source for PoE type 4?
100w
What is the maximum current per pair for PoH?
1000mA
what is the maximum operating temperature for cabling?
140 degrees F
what cable jacket temperature rating is recommended for cabling that will be used in BAS/BMS?
167 degrees F
what is the minimum recommended category of balanced twisted pair cabling for AV systems?
shielded category 6A
what size conductors are recommended for lighting systems?
23awg min/ 22awg
what is the minimum recommended category of balanced twisted pair cabling for WLAN systems?
category 6A
patch cords smaller in diameter than ___ awg shall not be used to support delivery of power
28 awg
how does temperature rise affect the electrical performance of a cable?
temperature rise causes electrical performance of the cable to degrqde
what is the maximum number of cables in a cable bundle?
24 cables
name the three factors used to determine NEC ampacity ratings for balanced twisted pair cabling
- bundle size
- conductor diameter (awg)
- cable temp ratings
what is the most common cable temp rating?
60 degrees C (140 degrees F)
how is PoE transmitted?
using common mode voltage on the cable pairs
why are metal body 8P8C connectors recommended for PoE applications instead of plastic ones?
metal improves hear dissipation
why should 50 micron gold plated tines be specified for PD modular connectors and parch cords?
connectors and patch cords without gold plating will fail earlier when uses for PoE
what drawback is associated with deploying large numbers of PoE switches?
significant wasted power
what is an advantage of specifying the use of midspan devices?
they offer power to PoE devices on legacy switches
why should power injectors be located as close as possible to the receiving equipment or device
minimize power loss and heating of cabling
Name the three methods for connecting work areas to a centralized cross connect
- pull through cables from the centralized cross connect
- interconnection cabling in a floor serving telecom space
- spliced cabling in a floor serving telecom space
Where is the pull through method typically used?
In small one or two story buildings with a limited number of users
Where is the backbone cabling method typically used?
In larger buildings where permanently routed backbone cables would minimize disruption to firestop assemblies when adding new users
True or False
A centralized optical fiber cabling installation can be deployed between buildings or across campus
False, centralized means in a building
What is the recommended length limit for pull through method
1000ft maximum or maximum length for the application, whichever is smaller
Name the three primary components of an FTTO system
- passive cabling
- containment system
- active network equipment
Describe the construction of a pre terminated assembly
a 2 strand fiber cable that has been terminated with LC connectors on one side
How many work areas are served by a micro switch?
1 to 2
What topology serves as the basis of an FTTO system?
Centralized cabling topology
True or False
The FTTO design does not use any active equipment in the floor TR or TE
True
Name four variants of redundancy possible in the FTTO design
- Variant 1: classical FTTO with cascading via balanced twisted pair cable
- V2: classical with cascading via optical fiber cable
- V3: dual homing - double fiber connections
- V4: dual homing - single fiber connection
What is a PON?
Point to Multipoint network architecture in which unpowered optical splitters are used to enable a single fiber strand to serve multiple end points
Name three advantages of a PON
- reduces physical cabling
- minimizes telecom space requirements
- reduces electrical power needed
Name the five primary PON variations
- BPOND (legacy)
- GPON
- EPON
- 10GPON
- 10G-EPON
What enables bidirectional communications over one strand of optical fiber as well as multiplication capacity in PON systems?
WDM technology
What is commonly referred to as the aggregation point for PON architecture?
Optical Line Terminal (OLT)
Which components acts as the user interface for the PON system?
Optical Network Terminal (ONT)
Name the two commonly deployed enterprise PON ONTs
- 4 port desktop ONT
- Faceplate style ONT
What is the maximum channel attenuation for IEEE 802.3 EPON?
20 dB
What is the maximum supported distance for IEEE 802.3 EPON?
6.2 mi
What is the maximum channel attenuation for ITU G.987 10GPON?
31 dB
What is the maximum supported distance for ITU G.987 GPON?
25 mi
What is the purpose of the passive optical splitter?
To split the single fiber output from each PON link existing the OLT to a variety of splitter ratio outputs
What split ratio is typically used for enterprise PON deployments?
1:32
What serves as the permanent link of a PON?
A simplex singlemode optical fiber cabling connection
What is usable floor space?
The building area used by occupants for their normal daily work functions
How much space is commonly allocated for an individual workspace?
100 sq ft
How much total floor space should be allocated for every BAS outlet?
250 sq ft
How many cables should be provided for each system or coverage area in a BAS?
1 cable
Telecom outlets should not be placed back to back in adjacent rooms, why?
compromises sound barrier and firestop
Why are telecom boxes mounted at the same height as electrical outlet boxes?
uniform appearance and accessibility in the work area
A conduit run should have no single bend greater than ___ degrees
90 degrees
A conduit run should not contain an aggregate of bends in excess of __ between pull boxes
180 degrees
What is the length limitation for continuous sections in a conduit run?
100ft
What is a conduit body?
A conduit coupling that has a removable cover
What is the primary purpose of a conduit body?
To give access to or change direction of the conduit system
Name the three most common styles of conduit body
- 90 degree bend
- T configuration
- C or straight line fitting
What formula is used to calculate the cross sectional area of a cable or conduit?
Cross Sectional Area = 0.785x d squared
How should the pathway design be adapted if the conduit run requires more than two 90 degree bends?
Add pull boxes
How should the pathway design be adapted if the conduit run requires a reverse bend?
Add pull boxes at each angle from 100 to 180 degrees
Name three instances where a third bend may be permitted in a conduit run
- total run is not longer than 33 ft
- conduit size is increase
- one bend is within 12 in of the cable feed end
Name two requirements for placing a pull box in a ceiling space
- Pull box must be listed for that purpose
- Ceiling panel must be marked and removable
What is the minimum length for a pull box?
16 times the diameter of the largest conduit
What are the depth and width requirements for the pull box?
Must be adequate for fishing, pulling and looping cable
True or False
A slip sleeve should be used as a splice location?
False
What term refers to a sheet metal housing that is placed over an opening in a conduit run?
Gutter
What is the advantage of underfloor conduit systems?
Low installation cost for areas with only a few outlets
Name the two general types of access floors
- standard height floor
- low profile floor
What is the most common type of access floor?
Standard height floor
How are low profile floors defined?
Floors less than 6 in high
What are the four typical components of an access floor?
- steel footings
- pedestals
- floors with or without stringers
- modular floor panels
What are the three major purposes of stringered systems?
- to brace pedestals
- to provide additional support for panels
- facilitates frequent removal and replacement of floor panels
What is the sole support for panels in freestanding and cornerlock access floors?
Pedestals
What is the finished height restriction for freestanding systems?
12 in or less
What is the recommended clearance for cable or cable pathways in low profile floors?
0.75 in
What is the minimum clearance for standard height floors in a general office area?
6 in above structural floor
What is the recommended clearance for standard height floors in a general office area?
8 in above structural floor
What is the recommended minimum clearance for standard height floors in a general office area when multiple systems will be installed?
12 in above structural floor
What is the required finished floor height where the plenum will be used for HVAC?
12 in or greater
How much free space is required between the top of the cable tray side rails and the underside of the stringers?
Minimum of 2 in
What two common types of building structures should be considered when planning access flooring for new and existing buildings?
- depressed slab
- normal slab
What materials should be used to cover floor panels in a computer room?
High pressure laminate, vinyl or other durable tiles
What materials should be used to cover floor panels in an office?
Factory laminated carpet or no material
What is the uniform load capacity for a medium duty ER?
100 lbf/sqft
What is the concentrated load capacity for a medium duty ER?
2000 lbf
What is the uniform load capacity for a medium duty general office?
50 lbf/sqft
Name two causes of dynamic load?
- accidental impact
- rolling objects
Name four methods of containment for main runs
- dedicated routes
- enclosed raceway distribution
- cable trays
- cable matting
How much clear vertical space is needed above conduits in a ceiling space?
Min 3in
How much clear vertical space is needed above raceways in a ceiling space?
Min 12in
What size zones are used with the ceiling zones method?
Into ~250 sqft to ~1000 sqft zones
How much space should be between a suspended ceiling and cabling pathways?
Up to 6 in
What is the maximum interval spacing that can be used between non continuous cable supports? (j hooks)
5ft
What is a utility column?
A post used by a ceiling distribution system
Name two requirements for concealing cabling behind walls
- An unimpeded vertical path
- A pull cord
How are cable tray systems commonly used?
As distribution systems for cabling within a building
What type of cable tray consists of two side rails connected by individual transverse rungs or stringers?
Ladder
What type of cable tray has a ventilated bottom with side rails?
Ventilated trough
How wide is a ventilated channel cable tray?
No more than 6in
What type of cable tray is an open tray having a central rigid spine with cable support ribs along the length at 90 degree angles?
Spine
What is a basket tray?
A cable tray made of a welded steel wire mesh
Name four types of cable tray fittings
- Elbows
- Reducers
- Crossovers
- Tees
Name five types of accessories used with cable trays
- Covers
- Hold down devices
- Dropouts
- Conduit Adapters
- Dividers
What determines a cable tray systems load capacity?
- Static load capacity of the tray
- Length of the support spans
Name three items that are installed to support cable trays
- cantilever brackets
- trapeze supports
- individual rod suspension brackets
Trays and wireways are usually supported on __ centers unless they are designed for greater spans
5ft centers
A support shall also be placed within ___ on each side of any connection to a fitting in cable tray
2ft on each side
True or False
Cable trays may be used as walkways, ladders or support for personnel
False
Where are messenger or support strands used?
In ceiling voids, crawl spaces, tunnels and areas with unfinished, exposed or structural ceilings
How are perimeter pathways often used?
to serve work areas where telecom devices can be reached from walls or partitions
What is the practical capacity for telecom cabling in perimeter raceways?
Between 20 and 40 percent fill, depending on cable bending radius
Where should perimeter raceways be used?
Small floor areas where the majority of telecom service will be along walls
Name three types of molding raceways
- picture molding for use in rooms
- wood or eaves trough metal molding for use in hallwys
- baseboard and crown molding
What is the recommended separation between telecom and electrical pathways running in parallel?
Min 2in
Name the two purposes of a poke thru device
- Maintain floor fire rating
- Provide power and telecom cabling to open spaces
How many interior TTYs must be provided in a covered shopping mall?
1, regardless of amount of phones
What locations in a hospital are required to provide TTYs on a public phone?
- Emergency room
- Waiting room
- Recovery room
Where are TTYs required in bus and rail facilities?
At the entrance to the facility
Where are TTYs required in an airport?
- Concourse within the security area
- Baggage claim area
What percentage of the first 100 rooms of a hotel must be equipped with a TTY?
4 percent
Under the ADA what is the maximum high side reach for unobstructed high side reach telephones?
48in
Under the ADA what is the maximum high forward reach for unobstructed forward reach telephones?
48in
What is the universal installation height for telephones?
48in
Under the ADA how many public telephones in a newly constructed facility must be equipped with volume control?
25 percent
What does TTY stand for?
Teletypewriter
True or False
Unless a state law or local building code adopts the ADA requirements, state and local building inspectors will not enforce the law
True, ADA is a civil rights law. Unless it is a state law or local building code it is not enforceable
How is the ADA enforced?
By action of an aggrieved party (lawsuit)