WGU D413 - Telecomm and Wireless Communications -VNO1 questions and answers with 100% accuracy (2026-2027 latest update)

Frequency Division Multiplexing (FDM)

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

Frequency Division Multiplexing (FDM)

Multiplexing used for television network to broadcast local news content using analog signals.

Wavelength Division Multiplexing (WDM)

Optical multiplexing using different light wavelengths for channels.

Wavelength Division Multiplexing (WDM)

Multiplexing used commonly in telecommunication systems and computer networks that use laser systems to send light signals over fiber optic cables.

Time-division multiplexing (TDM)

Used to send and receive digital signals between connected devices

Time-division multiplexing (TDM)

Each user periodically gets the entire bandwidth for a small burst of time, i.e. entire channel is dedicated to one user but only for a short period of time.

Time-division multiplexing (TDM)

It is very extensively used in computer communication and telecommunication.

Synchronous Time-division multiplexing (STDM)

Transmits each signal from one input source via a single time slot through the creation of different slots

Synchronous Time-division multiplexing (STDM)

Fixed time slots synchronized to a clock.

Asynchronous Time-division multiplexing (ATDM)

Randomly allocates time slots to different data signals depending on the rate at which they are being generated from the source

Code Division Multiplexing (CDM)

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

Code Division Multiplexing (CDM)

A multiplexing technique used extensively by the military and cellular phone companies in which binary 1s and 0s are replaced with larger, unique binary sequences to allow multiple users to share a common set of frequencies.

Code Division Multiplexing (CDM)

Employs spread spectrum technology and a special coding scheme (where each transmitter is assigned a code).

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.

Orthogonal Frequency Division Multiplexing (OFDM)

Multiplexing that divides the allotted frequency into channels like frequency hopping and direct sequencing. Digital.

Router

Connects various networks together and provides a few alternate routes for a data packet to travel.

Router

Networking component used to provide a device with a wireless connection point to a network

Router

Network component facilitates the connection of a network device to other network devices and to the internet.

Repeater

Regenerates digital signals, allowing the network media to exceed its recommended length

Hub

Provides a central connection point for a network

Switch

Serves as a central connection point and can provide network segmentation

Gateway

Provides a connection between the local area network and the Internet.

Media Converter

Used to convert one type of electrical signal into another type of electrical signal.

Cat 5

Frequency: 100mHz

Data Rate: 100Mbps

Distance: 100m/330ft

Found commonly in 10BaseT and 100BaseTX networks.

Cat 5e

Frequency: 100mHz

Data Rate: 1 Gbps

Distance: 100m/330ft

Cat 6

Frequency: 250mHz

Data Rate: 1 Gbps

Distance: 100m/330ft

Cat 6a

Frequency: 500mHz

Data Rate: 10 Gbps

Distance: 100m/330ft

Cat 7

Frequency: 600mHz

Data Rate: 10 Gbps

Distance: 100m/330ft

Cat 7a

Frequency: 1000mHz

Data Rate: 10 Gbps

Distance: 100m/330ft

Cat 8

Frequency: 2000mHz

Data Rate: 40 Gbps

Distance: 30m/1000ft

Physical Layer (Layer 1)

Concerned with the media, hardware, and topology of a network.

Data Link Layer (Layer 2)

OSI model layer where data is organized into frames or packets, and the packets are constructed, ready to go out onto the transmission media.

Network Layer (Layer 3)

OSI Model Layer that provides a means of routing data packets across a WAN, MAN, or GAN.

Transport Layer (Layer 4)

Responsible for the flow of data to and from the destination computer.

Session Layer (Layer 5)

Establishes a dialog between the source and destination computers.

Presentation Layer (Layer 6)

Translates the information into a format that the sender and receiver both understand. Data encryption also occurs at the presentation layer.

Application Layer (Layer 7)

Point of communication for applications installed on a device.

802.11a

Frequency: 5GHz

Data Rate: 54 Mbps

Distance: 50m/165ft

802.11b

Frequency: 2GHz

Data Rate: 11 Mbps

Distance: 100m/330ft

802.11g

Frequency: 2.4 and 5GHz

Data Rate: 54 Mbps

Distance: 100m/330ft and 50m/165ft

802.11n

Frequency: 2.4 and 5GHz

Data Rate: 600 Mbps

Distance: 300m/985ft

802.11ac

Frequency: 5GHz

Data Rate: 1.3 Gbps

Distance: 8 DL MU-MIMO

802.11ax

Frequency: 2.4 and 5GHz

Data Rate: 9.6 Gbps

Distance: 8 DL/UL MU-MIMO

IEEE 802.1

High Layer LAN Protocols standard

IEEE 802.1x

Port-based security for wireless network access control (authentication) standard.

IEEE 802.3

Ethernet Standard

IEEE 802.3af

Power over Ethernet (PoE) standard

IEEE 802.5

Token ring networking devices and data handling standard.

IEEE 802.11

Wireless Local Area Networking (WLAN) Standard

IEEE 802.15

Wireless Personal Area Network (WPAN), Bluetooth, and ZigBee standard

IEEE 802.16

Wireless Metropolitan Area Network (WMAN), WiMAX, and Mobile Wireless standard

IEEE 802.20

Mobile Broadband Wireless Access (MBWA) Standard

ISO/IEC 7498-1

OSI Model standard

ISO/IEC 11801

Cabling standard for network installations

ISO/IEC 8802

Ethernet Standards including 802.3

ISO/IEC 27001

Information security management systems (ISMS) standard

ISO/IEC 27002

Information security controls standard

ISO/IEC 27017

Standard for cloud security.

ISO/IEC 27018

Standards for cloud privacy.

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

A piece of equipment that connects a T-carrier leased line from the telephone company to a customer's equipment (such as a router). It performs line encoding and conditioning functions, and it often has a loopback function for testing.

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

A device or a set of devices used in telecommunications to connect a customer's equipment to a digital communication line.

CSMA/CD (Carrier Sense Multiple Access/Collision Detection)

Resends packet if collision is detected.

CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance)

Tries and waits for an opening to avoid a collision.

RG-6

A type of coaxial cable with an impedance of 75 ohms and that contains an 18 AWG core conductor. is used for television, satellite, and broadband cable connections.

RG-8 (Thicknet)

A very rigid coaxial cable with a solid copper conductor in the center. Allows for longer segments than other copper-core cables but because of the difficulty in handling the cable and thickness makes it difficult to install.

RG-58 (Thinnet)

A coaxial cable that is smaller in diameter and easier to work with. It does not carry signal as far as other cables and is still permitted for use but not recommended.

Twisted Pair

A type of cable that consist of four pairs of conductors. was first used on telephones today is the most common type of networking cable

Straight-through cable

A cable that is constructed with each numbered pin connecting to the matching numbered pin on the opposite end of the cable. These cables are used to connect computers with hubs.

Crossover cable

A twisted pair patch cable in which the termination locations of the transmit and receive wires on one end of the cable are reversed. are used to connect computers to other computers.

Rollover cable

A special cable in which the pin order is completely reversed on one end of the cable. Pin 1 connects to pin 8, pin 2 connects to pin 7, and so on.

Wi-Fi Protected Access (WPA)

Protocol that combines authentication with encryption. It uses RC4 and Temporal Key Integrity Protocol (TKIP).

TKIP is a 128-bit per-packet key, meaning that it dynamically generates a new key for each packet.

W-Fi Protected Access 2 (WPA2)

Based on the IEEE 802.11i standard.

It provides the following: The Advanced Encryption Standard (AES) using the Counter Mode-Cipher Block Chaining Message Authentication Code Protocol (CCMP).

This provides data confidentiality, data origin authentication, and integrity for wireless frames

Parity Check

A method of verifying the integrity of transmitted data.

Cyclic Redundancy Check (CRC)

Uses mathematical algorithm to determine if any bits are corrupt. After corruption has been detected it can correct it without requiring retransmission of data. Only downside is using this means more data has to be transmitted slowing down transmission rates.

Jitter

Consist of small staggers or hesitations in the delivery sequence of audio or video data caused by latency or missing packets.