Everything You Need To Learn About Telecommunications

130 Questions | Total Attempts: 48

SettingsSettingsSettings
Please wait...
Telecommunication Quizzes & Trivia

Do you know what is the characteristic of light in a light beam? How do you monitor the status of optical nodes? Check out our online quiz and learn interesting information along the way.


Questions and Answers
  • 1. 
    Which standards organization is considered to be the creator of the world's most recognized communications standards, known as recommendations?
    • A. 

      The Telecommunications Industry Association (TIA).

    • B. 

      The Society of Cable Telecommunications Engineers (SCTE).

    • C. 

      The International Telecommunication Union (ITU).

    • D. 

      The Institute of Electrical and Electronics Engineers (IEEE).

  • 2. 
    In which component in a fiber-optics communication system do changes to the intensity of the optical signal occur?
    • A. 

      The optical detector.

    • B. 

      The fiber-optic cable.

    • C. 

      The optical transmitter.

    • D. 

      The optical receiver.

  • 3. 
    What is a drawback of using Fabry-Perot (F-P) lasers in high-speed data (HSD) networks?
    • A. 

      The emission of a number of discrete wavelengths or side modes.

    • B. 

      The narrow emission pattern limits the power output.

    • C. 

      The size and greater expense to operate.

    • D. 

      The gain in the number of light photons.

  • 4. 
    Why are laser diodes most effective when coupled to singlemode fiber?
    • A. 

      The laser is the least expensive type of light source.

    • B. 

      Gas lasers do not provide a high speed modulation option applicable to both analog and digital fibers.

    • C. 

      Its high coupled power, directionality, and speed.

    • D. 

      The laser's wavelength is 75 degrees from the transmitted wavelength.

  • 5. 
    What are the factors that contribute to an optical receiver's sensitivity?
    • A. 

      Orientation, responsivity, response time, linear response, back reflection, and optical detector material.

    • B. 

      Location, responsivity, response time, linear response, back reflection, and optical detector material.

    • C. 

      Noise, responsivity, response time, linear response, back reflection, and optical detector material.

    • D. 

      Manufacture date, responsivity, response time, linear response, back reflection, and optical detector material.

  • 6. 
    What is a positive-intrinsic-negative (PIN) diode?
    • A. 

      An optical detector with current flow that is nonlinear to the intensity of light photons, with one electron/hole pair created for every absorbed photon until saturation.

    • B. 

      An optical detector with current flow that is linear to the intensity of light photons squared, with two absorbed photons created for every electron/hole pair until saturation.

    • C. 

      An optical detector which provides gain with current flow that is proportional to the intensity of light photons, as two absorbed photons are created for every electron/hole pair until saturation.

    • D. 

      An optical detector with current flow that is linear to the intensity of light photons, with one electron/hole pair created for every absorbed photon until saturation.

  • 7. 
    What does the amplification process in an avalanche photodiode (APD) introduce into the electrical output of an optical detector?
    • A. 

      Noise.

    • B. 

      Kinetic energy.

    • C. 

      Low bias voltage to the optical transmitter.

    • D. 

      Valence electrons.

  • 8. 
    What functions does the detector in an optical receiver perform?
    • A. 

      Conversion of an electrical signal to an optical carrier, and demodulation of the modulated optical carrier.

    • B. 

      Conversion of an optical carrier to an electrical signal, and modulation of the demodulated optical carrier.

    • C. 

      Conversion of an optical carrier to a digital signal, and encoding of the digital signal to an analog signal.

    • D. 

      Conversion of an optical carrier to an electrical signal, and demodulation of the modulated optical carrier.

  • 9. 
    What happens if the optical signal exceeds the maximum specified input power into a photodetector?
    • A. 

      Nonlinear operation resulting in distortion, back reflection, and signal loss.

    • B. 

      Nonlinear operation resulting in distortion, data errors, and signal loss.

    • C. 

      Nonlinear operation resulting in thermal noise, shot noise, and signal loss.

    • D. 

      Nonlinear operation resulting in distortion, data errors, and responsivity.

  • 10. 
    What is a characteristic of light in a laser beam?
    • A. 

      The laser beam consists of a wide range of wavelengths (monochromatic), with all light waves in phase (coherent light).

    • B. 

      The laser beam consists of a limited range of wavelengths (monochromatic), with all light waves out of phase (coherent light).

    • C. 

      The laser beam consists of a limited range of wavelengths (monochromatic), with all light waves in phase (coherent light).

    • D. 

      The laser beam consists of a wide range of wavelengths (monochromatic), with all light waves out of phase (coherent light).

  • 11. 
    Monitoring the status of optical nodes 
    • A. 

      Involves the use of a node transponder that continuously monitors a number of critical functions.

    • B. 

      Is a completely separate function from generating an alarm when parameters exceed a preset threshold.

    • C. 

      Involves monitoring the most critical functions except for temperature and a tamper switch mechanism.

    • D. 

      By remote means is not critical for maintaining network stability and reliability.

  • 12. 
    Digital return path transmissions 
    • A. 

      Multiplex each input by processing it through a digital-to-analog (D/A) converter.

    • B. 

      Cause the dynamic range of the return path to be greatly decreased.

    • C. 

      Use dense wavelength division multiplexing (DWDM) digital return transmitters in hub-to-headend architectures.

    • D. 

      Use digital return transmitters that typically have four inputs.

  • 13. 
    Broadband cable operators provide customers with high-speed data (HSD) connections to the Internet via their HFC networks using what standard?
    • A. 

      High-Speed Data Over Cable Specification (HSDOCS)

    • B. 

      Passive Optical Network Specification (PONS).

    • C. 

      Data Over Cable Service Interface Specification (DOCSIS).

    • D. 

      Digital Subscriber Line (DSL).

  • 14. 
    What is MPEG (Moving Picture Experts Group)?
    • A. 

      A universally accepted standard for digital television that does not take into consideration audio storage, channel compression and decompression, transport or display.

    • B. 

      A two-phase standard, with MPEG-1 being the most recognizable as related to data transport.

    • C. 

      A universally accepted standard for digital television, first released in 1992.

    • D. 

      Ten standards in one for the digitally coded representation of moving pictures.

  • 15. 
    Which of the following is true about optical nodes?
    • A. 

      They serve as the interface between the customer premises and the coaxial network.

    • B. 

      They convert RF signals to fiber-optic signals at the node's optical receiver before routing them to an RF amplifier module.

    • C. 

      They contain four main sections: the optical receiver, the RF amplifier module, the reverse optical transmitter, and the DC power supply.

    • D. 

      They receive return path signals from a diplex filter at the input of the forward optical transmitter.

  • 16. 
    What product based on the Data Over Cable Service Interface Specification (DOCSIS) defines the protocols for Internet protocol (IP) telephony over hybrid fiber/coax (HFC) networks?
    • A. 

      Digital telephony services (DTS).

    • B. 

      Circuit-switched voice.

    • C. 

      PacketCable.

    • D. 

      Voice over Internet protocol (VoIP).

  • 17. 
    In a centralized server video-on-demand (VOD) architecture,
    • A. 

      Servers store VOD content at each headend and hub location.

    • B. 

      The number of servers needed for video content storage is smaller than in the distributed server architecture.

    • C. 

      QAM modulators located in the customer premises convert video content to RF for delivery over the HFC network to the regional headend.

    • D. 

      Video content is transmitted to hub sites using SONET (synchronous optical network) analog transport and then converted to an intermediate frequency (IF) for delivery over the hybrid fiber/coax (HFC) network.

  • 18. 
    Which of the following statements about local ad insertion is true?
    • A. 

      Local ad insertion is performed usually by a video server.

    • B. 

      Cable operators can replace only local TV ads with their own commercial content, such as upcoming pay-per-view (PPV) events or featured sales presentations.

    • C. 

      Local advertising is broadcast in addition to all network commercials, so the network commercials aren't replaced.

    • D. 

      Large three-quarter-inch tape decks are used to play local advertisements because of the digital programming.

  • 19. 
    In regard to providing high-speed data (HSD) service,
    • A. 

      Data speeds are not affected by the number of customers using the network at a given time.

    • B. 

      The cable modem termination system (CMTS) can provide a data transfer rate up to 38 Mbps, using 256-QAM in a single 6 MHz channel.

    • C. 

      CMTS units are housed only in regional or secondary hubs and not in a system's headend.

    • D. 

      The CMTS can only provide a data transfer rate of up to 27 Mbps, using 256-QAM in a 6 GHz bandwidth.

  • 20. 
    Which of the following is true about the synchronous optical network (SONET) transmission standard?
    • A. 

      SONET defines optical carrier (OC) levels that increase by a factor of five, starting with OC-4.

    • B. 

      SONET defines optical carrier data rates and interface standards that enable only local carriers within a state to interconnect their existing fiber-optic systems.

    • C. 

      SONET is the North American standard used for telephony applications.

    • D. 

      SONET is a fiber transmission standard that addresses generic requirements for optical amplifiers and proprietary dense wavelength division multiplexing (DWDM) systems.

  • 21. 
    Why was the zero-dispersion point in single-mode fiber moved to 1,550 nm?
    • A. 

      To take advantage of the low water peak region at 1,550 nm in single-mode fiber.

    • B. 

      To take advantage of the resistance to the distortion known as four-wave mixing (FWM) at 1,550 nm in single-mode fiber.

    • C. 

      To take advantage of the low intrinsic absorption and lower attenuation at 1,550 nm in single-mode fiber.

    • D. 

      To take advantage of the tolerance for bending at 1,550 nm in single-mode fiber.

  • 22. 
    What type of single-mode fiber is intended for fiber-to-the-home (FTTH) installations?
    • A. 

      The ITU-T G.657 FTTH fiber.

    • B. 

      The ITU-T G.657 depressed-clad fiber (DCF).

    • C. 

      The ITU-T G.657 bend-insensitive fiber (BIF).

    • D. 

      The ITU-T G.657 matched-clad fiber (MCF).

  • 23. 
    What are the primary causes of intrinsic loss in single-mode fiber?
    • A. 

      Material absorption and residual metal ions, which are introduced during the manufacturing process.

    • B. 

      Material absorption and Rayleigh scattering.

    • C. 

      Rayleigh scattering and total internal reflection.

    • D. 

      Excessive bending and Rayleigh scattering.

  • 24. 
    The phenomenon, total internal reflection, is what enables an optical fiber to guide light. What characteristic of optical fiber causes total internal reflection?
    • A. 

      The identical refractive indexes of the cladding and core cause light to be reflected within the core along the optical fiber.

    • B. 

      The difference in refractive indexes, between cladding and core, causes light to be reflected off the cladding and back into the core along the optical fiber.

    • C. 

      The difference in refractive indexes, between cladding and core, causes light to be reflected off the core and back into the cladding along the optical fiber.

    • D. 

      The identical refractive indexes of the cladding and core cause light to be reflected off the cladding and back into the core along the optical fiber.

  • 25. 
    Where would you expect Fresnel reflections to occur in a fiber-optic network?
    • A. 

      At the macrobends in the optical fiber.

    • B. 

      At the Fresnel interface in the optical receiver.

    • C. 

      At connections and mechanical splices where the signal source is entering or exiting the cable.

    • D. 

      Inside the laser.

Back to Top Back to top