D413 WGU TELECOM EXAM 2025/2026 QUESTIONS AND ANSWERS 100% PASS.

D413 WGU TELECOM EXAM 2025/2026
QUESTIONS AND ANSWERS 100% PASS.




OFDM - ANS Orthogonal Frequency Division Multiplexing
Type: Digital
Principle: Splits subchannels into their own frequency
Real world example: WiFi


TDM - ANS Time Division Multiplexing
Type: Digital
Purpose: Gives each frequency their own time slot
Real world example: SONET


WDM - ANS Wavelength Division Multiplexing
Type: Optical
Purpose: Used to split fiber frequencies
Real world example: Fiber internet backbone


DWDM - ANS Dense Wave Division Multiplexing
Type: Optical
Purpose: Used to send long distance high-capacity networks


FDM - ANS Frequency-Division Multiplexing:

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, Type: Analog
Purpose: A technique that permits information from several channels to be assigned bandwidth
on one wire based on frequency.
Real world example: FM radio, Cable TV


ATDM - ANS Asynchronous time division multiplexing
Type: Digital
Purpose: Sends traffic at variable time intervals


STDM - ANS Synchronous Time Division Multiplexing
Type: Digital
Purpose: Fixed time intervals


CDM - ANS Code Division Multiplexing
Type: Digital
Purpose: Unique codes for different channels


What is the difference between analog and digital in multiplexing? - ANS Analog multiplexing
→ combines analog signals using frequencies or wavelengths.
Digital multiplexing → combines digital signals using time slots or codes.


CWDM - ANS Coarse Wavelength Division Multiplexing
Type: Optical
Purpose: Shorter/Cheaper Links


Cat 1 - ANS Max data rate: 1mbps
Bandwidth: .4MHz
Max distance: 100M
Use: Old analog voice

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