WGU D413 Practice Questions | Telecommunications & Wireless Communications | Actual Open-Ended Prep Q&As with Explanations & Active Recall Formatting (2026/2027 Edition) PDF

WGU D413 Practice Questions | Telecommunications &
Wireless Communications | Actual Open-Ended Prep Q&As
with Explanations & Active Recall Formatting (2026/2027
Edition) PDF
Introduction

Are you struggling to wrap your head around the complex networking standards, wireless protocols, and
signal technologies in WGU D413 (Telecommunications and Wireless Communications)? Multiple-
choice practice tests can make you feel artificially confident because you can easily guess your way to the
right answer.

Coverage Breakdown

This study package offers comprehensive coverage across all 8 core competency zones assessed in the
WGU D413 course:

 Multiplexing & Signal Characteristics: PSK, FSK, QAM, ASK modulation; FDM, TDM, OFDM,
DWDM, and ATDM multiplexing; physical propagation concepts like absorption, attenuation, and
guard bands.
 Cabling & Physical Media: Twisted-pair copper specifications (Cat 5e to Cat 7), Ethernet physical
layers (10Base2, 10Base5, 10BaseT), single-mode vs. multi-mode fiber-optic wavelengths (850nm
and 1550nm), and physical connector standards (RJ-45, ST, SC, LC, FC, RG-6, RG-58).
 Wireless Technologies & Standards: Cellular network components (BTS, BSC, GSM, 4G LTE,
5G), terrestrial propagation, Wi-Fi standard specifications (802.11a/g/n/ac/ax/ad/ah), media access
rules (CSMA/CA), and low-power IoT technologies (Zigbee, LoRaWAN, NFC).
 Error Detection & Control: Structural integrity checks including Cyclic Redundancy Check (CRC),
Echo Checks, Parity (Even/Odd), Checksums, and crosstalk interference.
 OSI Layers & Network Devices: Layer 1 to Layer 7 functions, hardware roles (bridges, routers,
hubs, switches, firewalls, CSU/DSUs), AAA proxies, Active Directory structures, and LLC/MAC
data-link sublayers.
 Modems, WAN, & Access Technologies: WAN delivery systems (ISDN, DSL, ADSL, SDSL, T1,
T3), broadband standards (DOCSIS), carrier frameworks (SONET), and advanced dynamic routing
protocols (BGP).
 Protocols & Standards: Core operational protocols (IP, TCP, UDP, DHCP, DNS, TLS), medium
access mechanisms (CSMA/CD), IPv6 transitional tunneling (6to4), and governing bodies (IEEE).
 Troubleshooting & Network Tools: Signal diagnostic issues (acoustical echo, packet jitter) and
foundational command-line/diagnostic utilities (Ping, Traceroute, Packet Sniffers).




Section 1: Multiplexing and Signal Characteristics

,1. Which digital modulation technique encodes data by varying the phase of the

carrier signal while keeping amplitude constant?

Phase Shift Keying

Phase Shift Keying alters the phase of the carrier wave to represent different digital values.

2. Which multiplexing technique divides the total available transmission bandwidth of

a single physical medium into separate frequency bands?

Frequency-Division Multiplexing

Frequency-Division Multiplexing splits the frequency spectrum of a physical link into several

discrete, non-overlapping bands.

3. Which type of digital multiplexing technique divides a single communication

channel into multiple non-overlapping, orthogonal subchannels?

Orthogonal Frequency-Division Multiplexing

Orthogonal Frequency-Division Multiplexing splits a single high-rate data stream into

multiple closely spaced, orthogonal, low-rate subcarrier channels.

4. Which multiplexing technique divides transmission time on a single channel into

fixed, non-overlapping intervals allocated to specific users?

Time-Division Multiplexing

, Time-Division Multiplexing allocates the entire bandwidth of a physical channel to different

users during distinct, pre-arranged time slots.

5. Which optical multiplexing technique combines multiple distinct light signals of

different wavelengths onto a single fiber-optic cable?

Dense Wavelength-Division Multiplexing

Dense Wavelength-Division Multiplexing packs multiple tightly spaced optical channels onto

a single fiber to maximize data transmission capacity.

6. Which dynamic multiplexing technique allocates time slots to active users only

rather than reserving fixed slots beforehand?

Asynchronous Time-Division Multiplexing

Asynchronous Time-Division Multiplexing dynamically distributes available transmission

time based on real-time demand rather than static scheduling.

7. Which multiplexing technique assigns a unique mathematical code to each

transmitter, allowing multiple signals on one frequency?

Code-Division Multiplexing

Code-Division Multiplexing uses orthogonal mathematical codes to separate distinct

channels transmitting simultaneously over the same frequency.