CCNA Chapter 3 Key Terms
Terms
undefined, object
copy deck
- AM (Amplitude Modulation)
- Modulates the height of the carrier wave.
- Angle of Incidence
- The angle at which the ray hits the glass surface.
- Angle of Reflection
- The angle at which the ray hits the glass surface.
- Attenuation
-
Loss of communication signal energy.
N0CCJ - backbone
- The part of the network that acts as rhe primary path for the traffic that is most often sourced from, and destined for, other networks.
- Coaxial Cable
- A cable consisting of a hollow outer cylindrical conductor that surrounds a single inner wire conductor.
- Crosstalk
- The unwanted reception of electromagnetic signals on a wire from a nearby wire.
- Dispersion
- The Broadening of the light signals along the length of the fiber.
- DSSS (Direct-Sequence Spread Spectrum)
- A Technologyin which transmissions are more reliable because each bit (1 or 0) is represented by a string of 1s and 0s, called a chipping sequence.
- EIA (Electronics Industry Association)
- A Group that specifies electrical transmission standards. The EIA and TIA have developed numerous well-known communication standards.
- FHSS (Frequency-Hopping Spread Spectrum)
- A technology in which transmissions hop from one frequency to another in random patterns. This feature enables the transmissions to hop around narrowband interference, resulting in a clearer signal and higher reliability of the transmissions
- Fiber-Optic Cable
- A physical medium capable of conducting modulated light transmission. Compared with other transmission media, fiber-optic cable is more expensive but is not susceptible to electromagnetic interference. Sometimes called optical fiber
- FM (Frequency Modualation)
- Modulates the frequency of the wave
- IEEE (Institute of Electrical and Electronic Engineers)
-
A proffesional organization whose activities include the development of communications and network standards.
N0CCJ - Impedance
- The Resistance to the movement of electron in an AC Circuit.
- Media
- The plural of medium. Media refers to vaious physical enviroments through which transmission signals pass.
- Modal Dispersion
- When Multiple modes of light propagating through fiber travel different distances, depending on their entry angles, which causes them to arrive at the destination at slightly different times,
- Multimode
- A type of fiber-optic cable that transmits more than one light path
- Noise
- An unwanted electrical signal on a wire that interferes with the quality of the signal by altering its shape.
- Patch Panel
- An Assembly of Pin Locations and Ports that can be mounted on a rack or wall bracketin the wiring closet. It acts like a switchboard that connects workstations cables to each other and to the outside.
- PM (Phase Modulation)
- Modulates the polarity (phase) of the wave.
- Reflection
- The photons of light striking a surface and leaving that surface in an equal but oppisite direction.
- Resistance
- The property of a material that resists electron movement.
- Refraction
-
The change of direction of a beam of a light when it enters another medium.
N0CCJ - RFI (Radio Frequency Interference)
- The noise on wires caused by radio signals.
- Single-Mode
- and optical fiber that has only one mode of light transmission. contrast with multimode.
- SS (spread spectrum)
- a modulation technique developed in the 1940's that spreads a transmission signal over a broadband of radio frequencies. The term spread spectrum describes a modulation technique that sacrifices bandwidth to gain signal-to-noise ratio.
- Standard
- A set of rules or procedures that are either widely used or officially specified.
- STP (shielded twisted pair)
- A two-pair wiring medium used in a variety of network implementations. STP cableing has a layer a layer of shielded insulation to reduce EMI.
- Thicknet
- an early form of coaxial cable using 10base5 for networking. Thicknet was once desirable because it could carry signals up to 500 meters.
- Thinnet
- A simple, thin, coaxial network cable for the 10base2 system. Thinnet can carry a signal only 185 meters, but was much easier to work with than thicknet.
- TIA (Telecommunications Industry Associations)
- A standards association that publishes standards for telecommunications.
- UTP (Unshielded Twisted Pair)
- A four pair wire medium used in a variety of networks.
- Wavelength
-
The length of a wave measured from anypoint on one wave to the corresponding point on the next wave, The wavelength of light is usually measured in nanometers (nm).
N0CCJ - WEP (Wired Equivalent Privacy)
- A security mechanism, defined within the 802.11 standard, that is designed to protect the over-the-air transmission between wireless LAN APs and NICs.