WGU D413 Telecommunication and Wireless questions and answers with 100% accuracy (2026-2027 latest update)

What Type of multiplexing is OFDM?Orthogonal frequency-division multiplexing

Digital

2 multiple choice options

What Type of multiplexing is TDM? Time-division multiplexing (TDM)

Digital

2 multiple choice options

What Type of multiplexing is DWDM? Dense wavelength-division multiplexing (DWDM)

Optical

2 multiple choice options

What Type of multiplexing is FDM?Frequency-division multiplexing

Analog/Digital

2 multiple choice options

What Type of multiplexing is ATDM?Asynchronous Time Division Multiplexing

Digital

2 multiple choice options

What Type of multiplexing is STDM?Synchronous Time Division Multiplexing

Digital

2 multiple choice options

What Type of multiplexing is CDM?code-division multiplexing (CDM)

Digital

2 multiple choice options

What is the Basic principle of OFDM?Orthogonal frequency-division multiplexing

Orthogonal Subchannels

2 multiple choice options

What is the Basic principle of TDM?

Time Slots

2 multiple choice options

What is the Basic principle of WDM?

Different Wavelengths

2 multiple choice options

What is the Basic principle of DWDM?

Dense set of wavelengths

2 multiple choice options

What is the Basic principle of FDM?

Frequency bands

2 multiple choice options

What is the Basic principle of STDM?

Fixed and Synchronized time invervals

2 multiple choice options

What is the Basic principle of ATDM?

Variable time intervals

2 multiple choice options

What is the Basic principle of CDM?

Unique Codes for each channel

2 multiple choice options

cyclic redundancy check (CRC)

Based on the same principle for error detection as a parity check but uses mathematical algorithms to deter-mine if any bits are corrupt.

Resistance

Opposition to direct current

Ω (ohm)

Current flow affected by cable length. Resistance is present in battery-powered circuits.

Impedance

Opposition to alternating current (AC)

Z

Current flow is affected by frequency, cable length, induction, and capacitance. Impedance is present in AC-powered circuits.

Category 1 UTP or STP

UDP

Category 2 UTP or STP

UTP

Category 3 UTP or STP

UTP or STP

Category 4 UTP or STP

UTP or STP

Category 5 UTP or STP

UTP or STP

Category 5e UTP or STP

UTP or STP

Category 6 UTP or STP

UTP or STP

Category 6a UTP or STP

UTP or STP

Category 7 UTP or STP

UTP or STP

Category 8 UTP or STP

STP

Category 1 Maximum Frequency Rating?

None

Category 2 Maximum Frequency Rating?

1 MHz

Category 3 Maximum Frequency Rating?

16 MHz

Category 4 Maximum Frequency Rating?

20 MHz

Category 5 Maximum Frequency Rating?

100 MHz

Category 5e Maximum Frequency Rating?

100 MHz

Category 6 Maximum Frequency Rating?

250 MHz

Category 6a Maximum Frequency Rating?

500 MHz

Category 7 Maximum Frequency Rating?

600 MHz

Category 8 Maximum Frequency Rating?

1800-2000 MHz

Category 1 Data Rate

Less than 1 Mbps

Category 2 Data Rate

4 Mbps

Category 3 Data Rate

10 Mbps

16 Mbps

Category 4 Data Rate

16 Mbps

Category 5 Data Rate

100 Mbps

1000 Mbps

Category 5e Data Rate

100 Mbps

1000 Mbps

Category 6 Data Rate

1 Gbps

Category 6a Data Rate

10 Gbps

Category 7 Data Rate

10 Gbps

Category 8 Data Rate

40 Gbps

Parity Check

which is a method of verifying the integrity of transmitted data.

Orthogonal Frequency Division Multiplexing (OFDM)

Transmission technique used with wireless devices that use the 5-GHz radio band and can achieve a data rate as high as 54 Mbps. It divides the allotted frequency into channels similar to frequency hopping and direct sequencing. Digital.

Dense Wavelength Division Multiplexing (DWDM)

An optical multiplexing technology that allows several different streams of data to travel down the same optical fiber simultaneously.

Frequency Division Multiplexing (FDM)

Divides the available bandwidth into frequency bands, and each band is used for a different communication channel. Analog or Digital.

Synchronous Time Division Multiplexing

Which multiplexing technique transmits each signal from one input source via a single time slot through the creation of different slots?

Asynchronous Time-Division Multiplexing

Which category of multiplexing randomly allocates time slots to different data signals depending on the rate at which they are being generated from the source?

Frequency Division Multiplexing (FDM)

A company is developing a television network to broadcast local news content using analog signals.Which multiplexing technique should be used?

Time-division multiplexing

Which type of multiplexing is used to send and receive digital signals between connected devices?

spread spectrum

The radio transmission technique that subdivides the allocated frequency range into smaller units called channels.

frequency hopping and direct sequencing

The two types of spread-spectrum transmission techniques are:

spatial multiplexing

Transmitting two or more streams of data in the same frequency channel

Cyclic Redundancy Check (CRC)

An enhanced parity check that not only identifies when an error occurs but also corrects the error.

Which cable realizes noise protection with the use of foil shielding?

A cable transmitting signals between 15 and 20 MHz

demodulation

The receiver separates the voice wave from the carrier wave.

Peak Amplitude

What is the absolute value of a signal's greatest magnitude in proportion to the energy that it is able to carry?

Wavelength Division Multiplexing (WDM)

Multiple communications channels are consolidated and then transmitted on lightwaves with different wavelengths. More common in telecommunication systems and computer networks that use laser systems to send light signals over fiber optic cables.

Code-division multiplexing (CDM)

Assigns a unique code to each channel, and all channels share the same frequency band simultaneously. Digital.

carrier-sense multiple access with collision avoidance (CSMA/CA)

Media access method that works much like CSMA/CD but tries to avoid, rather than detect, collisions.

carrier-sense multiple access with collision detection (CSMA/CD)

Media access method used by Ether-net networks to control and ensure data delivery.

orthogonal frequency-division multiplexing (OFDM)

Transmission technique used with wireless devices that use the 5-GHz radio band and can achieve a data rate as high as 54 Mbps.

spread spectrum

Transmission technique that uses multiple channels to transmit data either simultaneously or sequentially.

direct sequencing

Spread spectrum technique that transmits data on multiple channels sequentially.

Channel Service Unit/Data Service Unit (CSU/DSU)

Converts signals from the LAN into signals that can be carried by the T1 line, and vice versa.

What is the Ethernet standard known as 802.3?

Ethernet standard

What is the purpose of 802.3ad?

Link Aggregation (LAG)

At what frequency does 802.11a operate and what is its speed?

5 GHz with 54 Mbps

At what frequency does 802.11b operate and what is its speed?

2.4 GHz with 11 Mbps

At what frequency does 802.11g operate and what is its speed?

2.4 GHz with 54 Mbps

What are the frequencies and speeds of 802.11n?

2.4 GHz & 5 GHz with 600 Mbps

At what frequency does 802.11ac operate and what is its speed?

5 GHz with 1.3 Gbps

What are the frequencies and speed of 802.11ax (Wi-Fi 6)?

2.4 GHz & 5 GHz with 9.6 Gbps

802.3af / 802.3at

provide Power over Ethernet (PoE / PoE+)

802.11 is Wi-Fi standard

What is 802.1X used for?

Port-based Network Access Control (PNAC)

What is the purpose of 802.1Q?

Virtual LANs (VLANs)

What does 802.1Q VLAN refer to?

VLAN tagging protocol

Which protocol does 802.1D stand for?

Spanning Tree Protocol (STP)

What is the focus of 802.1p?

Quality of Service (QoS) prioritization

What does 802.15 relate to?

Wireless Personal Area Networks (WPAN)

What technology is associated with 802.16?

WiMAX (Worldwide Interoperability for Microwave Access)

What are the key specifications of Cat 5 cable?

Supports 100 Mbps, Maximum length of 100 meters, Operates at up to 100 MHz

What are the key specifications of Cat 5e cable?

Supports 1 Gbps, Maximum length of 100 meters, Operates at up to 100 MHz

What are the key specifications of Cat 6 cable?

Supports 1 Gbps, Maximum length of 100 meters, Operates at up to 250 MHz

What are the key specifications of Cat 6a cable?

Supports 10 Gbps, Maximum length of 100 meters, Operates at up to 500 MHz

What are the key specifications of Cat 7 cable?

Supports 10 Gbps, Maximum length of 100 meters, Operates at up to 600 MHz

What are the key specifications of Cat 7a cable?

Supports 10 Gbps, Maximum length of 100 meters, Operates at up to 1000 MHz

What are the key specifications of Cat 8 cable?

Supports 25/40 Gbps, Maximum length of 30 meters, Operates at up to 2000 MHz

What is Frequency Division Multiplexing (FDM)?

Analog multiplexing technique that divides bandwidth into frequency bands.

What is Time Division Multiplexing (TDM)?

Digital multiplexing technique that allocates time slots for each channel.

What is Synchronous TDM (STDM)?

A TDM variant with fixed time slots synchronized to a clock.

What is Asynchronous TDM (ATDM)?

A TDM variant with flexible time slots for varying data rates.

What is Wavelength Division Multiplexing (WDM)?

An optical multiplexing technique that uses different light wavelengths for channels.

What is Dense Wavelength Division Multiplexing (DWDM)?

A WDM variant that packs channels more closely for higher capacity.