Simplex - ANSWER-Transmits signals in only one direction (listener has no way to respond) and public address system is example
Half duplex -
... [Show More] ANSWER-Transmits signals in both directions but only once at a time (push to talk systems)
Full duplex - ANSWER-Transmits signals in both directions at the same time (telephones)
EMI - ANSWER-Electromagnetic interference
Alternating current - ANSWER-0 ➖ max ➖ 0
Direct current - ANSWER-0 ➖ max (battery)
RFI - ANSWER-Disturbance in electromagnetic signals
Frequency - ANSWER-Number of cycles a signal is repeated in time period
Bandwidth - ANSWER-Info carrying capacity of a system
Analog signal - ANSWER-Continuously varying signals that follow loudness(AMPT) and frequency(tone)
Digital signal - ANSWER-Non-continuous signal that changes from one state to another in a distinct order
Decibel - ANSWER-Measure of analog signal strength
Megahertz - ANSWER-Bandwidth of system in a frequency range of interest
Megabit - ANSWER-Number of bits of info that can be transported over the media
Resistance - ANSWER-Conductors ability to resist the flow of electrical energy
Inductance - ANSWER-Electrical forcefield around conductor that opposes changes in current flow
Capacitance - ANSWER-Storage of electrical charges when potential voltages exist between conductors
Mutual capacitance - ANSWER-Two conductors
Unbalanced capaitance - ANSWER-Conductors and ground
Impedance - ANSWER-Total opposition to current flow (AC circuits)
Characteristic impedance - ANSWER-Input impedance of a uniform analog transmission line of infinite length
Value of characteristic impedance - ANSWER--Material & diameter of conductors
-distance between conductors
-insulating values of seperators
Attenuation ( intersection loss ) - ANSWER-- measure of signal loss between transmitter and receiver
- measure of signal loss in the amplitude when signal is transmitted
- measure of decibels per unit length at a given frequency
- loss of usable signal during g transmissions
Return loss - ANSWER-Decibels of the power of the outgoing signal to the power of the reflected signal
Cross talk - ANSWER-Unwanted transfer of electromagnetic energy to 1 or more circuits
Near end crosstalk (NEXT) - ANSWER-Unwanted signal coupling from a transmitter at the near end into another pair measured at the near end
Far end crosstalk (FEXT) - ANSWER-Unwanted signal coupling from a transmitter at the near end into a neighboring pair measured at the far end
Nominal velocity of propagation (NVP) - ANSWER-Ratio of Speed of transmission along a cable relative to the speed of light in a vacuum
Propagation delay - ANSWER-Time it take for a signal to be transmitted from one end of a circuit to another
Delay skew - ANSWER-Difference in speed between the fastest and slowest pairs within the same cable
Insulation - ANSWER-The conductance of a cable indicates the potential for current to leak through the insulation, conductance in inversely related to resistance
Shielding purposes - ANSWER-- reduce the level of the signal radiated from the cable
- minimize the effect of external EMI on the cable pairs
- provide physical protection
Shielding characteristics - ANSWER-- foil will typically block higher frequencies (30 MHz and higher)
- copper braids will block lower frequencies
- solid tubing will block all frequencies
- CBCs may help divert all induced frequencies from susceptible cables
Structured cabling system (SCS) - ANSWER-Complete and collective configuration of cabling and associated hardware
Information technology systems (ITS) - ANSWER-- plain old telephone system (POTS)
- voice over internet protocol (VolP)
- unified messaging systems
- videoconferencing
- computer networking
Differences between ITS systems - ANSWER-- structure of the building
- cable and connection hardware
- function of the ITS cabling installation
- configuration of an existing cabling system
- warranties
- customer requests
Standardized ITS systems - ANSWER-- Conformance to physical and transmission installation
- consistency in cabling design and install
- a basis of examining a proposed system
- uniform documentation
SCS components - ANSWER-- backbone cabling and associated pathways
- cross connection facilities
- interconnection facilities
- cabling methods
- horz. Cabling and associated pathways
- work areas
- telecommunications outlets/connections
- consolidation points (CPs)
- multiuser telecom outlets assemblies (MUTOA)
- transition points
- centralized cabling
- distributed cabling
- admin (labeling, documentation)
Inter-building backbone - ANSWER-Distribution of telecom services between buildings
Intra-building backbone - ANSWER-Distribution of telecom services within one building [Show Less]