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

802.3

Ethernet standards

802.11

Wi-Fi Standards

802.1X

Port-based Network Access Control (PNAC) standard.

802.1D

Spanning Tree Protocol (STP) Standard

802.1Q

Protocol for VLAN tagging within networks.

802.1p

Quality of Service (QoS) standard.

802.3af / 802.3at

Standards for Power over Ethernet (PoE / PoE+).

802.3ad

Link Aggregation (LAG) standard

802.15

Wireless Personal Area Networks (WPAN) standard

802.16

WiMAX (Worldwide Interoperability for Microwave Access) standard

FDM (Frequency Division Multiplexing)

Analog multiplexing technique dividing bandwidth into frequency bands. Example radio/tv broadcasting

TDM (Time Division Multiplexing)

Digital multiplexing technique allocating time slots for each channel. example the Ethernet. Each user periodically gets the entire bandwidth for a small burst of time

STDM (Synchronous TDM)

TDM with fixed time slots synchronized to a clock and it is digital

ATDM (Asynchronous TDM)

TDM with flexible time slots for varying data rates. digital

WDM (Wavelength Division Multiplexing)

Optical multiplexing using different light wavelengths for channels.

Dense Wavelength Division Multiplexing (DWDM)

Enhanced WDM that packs channels more closely for higher capacity. Optical

Coarse Wavelength Division Multiplexing (CWDM)

An optical multiplexing technology in which a few signals of different optical wavelength could be combined to travel a fairly short distance.

CDM (Code Division Multiplexing)

Digital multiplexing technique that spreads signals using unique codes. and all channels share the same frequency band simultaneously.

Orthogonal Frequency Division Multiplexing (OFDM)

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

ISO/IEC 7498-1

OSI Model standard

ISO/IEC 11801

Standard for generic cabling for premises

ISO/IEC 8802

Ethernet Standards including 802.3

ISO/IEC 27001/27002

ISMS standards for security controls.

ISO/IEC 27017

Standard for cloud security.

ISO/IEC 7816

Specifications for smart cards.

802.11a

5 GHz

54 Mbps

20 MHz Channels

802.11b

2.4 GHz

11 Mbps

20 MHz Channel

802.11g

2.4 GHz

54 Mbps

20 MHz Channels

802.11n

2.4 GHz & 5 GHz

600 Mbps

4 SU-MIMO

20, 40, 80 MHz channels

802.11ac

5 GHz

1.3 Gbps

8 DL MU-MIMO

20, 40, 80+80, 160 MHz

802.11ax

2.4 GHz & 5 GHz

9.6 Gbps

8 DL/UL MU-MIMO

20, 40, 80+80, 160 MHz

Satellite Modem

Provides internet access in remote areas without landline or cable infrastructure. High latency, weather susceptibility, limited bandwidth, expensive service.

CSU/DSU

Facilitates high-speed WAN connectivity for LANs. Requires additional equipment, typically used for leased lines, limited flexibility.

Cable Modem

Offers high-speed internet access over existing cable TV lines. Shared bandwidth, speed degradation during peak times, occasional service outages.

DSL Modem

Provides high-speed internet access over traditional phone lines. Speed and reliability depend on distance from provider, signal quality may degrade over copper.

56k Modem

Offers basic internet access via dial-up phone lines. Slow speeds, ties up phone line during use, obsolete technology.

ISDN Modem

Provides digital voice and data transmission over phone lines. Limited availability, higher costs compared to DSL, speed limitations.

WiMAX Modem

Provides wireless broadband over long distances. Limited coverage area, signal interference, susceptibility to weather conditions.

Cellular Modem

Offers wireless internet access using cellular networks and data plans. Limited coverage in rural areas, data caps and throttling, potential for network congestion.

100Base-FX

MM Laser

400 meters half duplex

2k full duplex

100Base-SX

MM LED

300 meter

1000BASE-SX

MM Laser

550 meters

Short wavelength

1000BASE-LX

MM/SM Laser

550m/5k

Long Wavelength

10GBase-SR

MM Short range

26-400meters

10GBase-LR

SM Long Range

10 kilometers

802.19

Standard for coexistence of multiple wireless networks

802.8

Fiber optic standard for broadband networks

802.2

Logical link control standard for data communication

802.4

Standard for industrial automation networks

802.11

Wireless LAN standard for local networks

ISO 1801

Standard for energy-efficient communication networks

ISE 2017

International Symposium on Electronics

ISE 2018

Conference on Information Systems Engineering

CRC vs Parity Bit

Error detection methods in data transmission

Checksum

Error-checking method to ensure data integrity

IDSN BPS max and average

Metrics for maximum and average data transfer rates in ISDN

CAT 1

1 Mbps

10 MHz

Telephone and modem lines

analog

CAT 2

4 Mbps

4MHz

LocalTalk & Telephone

CAT 3

10 Mbps

100 Meters ,382ft

16 Mhz

10BASE-T ethernet

CAT 4

16 Mbps

20 MHZ

100 Meters, 328ft

token ring

CAT 5

100 Mbps

100 meters, 328ft

100 MHz

100BaseT Ethernet

CAT 5E

1 Gbps

100 meters, 328ft

100 MHz

100BaseT Ethernet, Residential homes

CAT 6

1 Gbps up to 100m

10 Gbps up to 55m

250 MHz

Gigabit ethernet, commercial buildings

CAT6a

10GBASE-T

100 meters

10Gbps

Gigabit Ethernet in data centers and commercial buildings

CAT7

10GBASE-T

10Gbps

100 meters

600 MHz

Core Infrastructure

Cat 7a

10 Gbps

100 meters

1000 MHz

40Gbos at 50 m/ 164 ft, 10Gbps core infrastructure

CAT8

40Gbps

30 meters

2000 MHz

used for core infrastructure

RG-6

1 Gbps AND 75 OHM

500 m DOCSIS

F-connector

Cable modem, TV

RG-58

A thin, flexible coaxial cable used in 10Base2 network. Also called thinnet.50 OHM

RG-8

A thick, rigid coaxial cable used in a 10Base5 network. Also called thicknet. 50 OHM

Single-mode fiber (SMF)

SMF cables typically work with transceivers labeled LX, LR, ER, or ZR, which use wavelengths like 1310 nm or 1550 nm.

Multimode Fiber (MMF)

MMF cables are used with SX or SR transceivers, usually operating at 850 nm. You need to use the appropriate transceiver for the fiber type.

Router

Connect multiple networks and direct data packets along the best routes

Repeater

Extend the reach of a network by regenerating signals

Hub

Provides a central connection point for a network devices

switch

Provide network segmentation and central connections.

Gateway

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

Bridges

Segment larger networks to reduce collisions

Media Converter

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

Physical Layer - Layer 1

Transmits raw bits over physical media. Hubs, Repeaters, Cables, Network Interface Cards

Data Link Layer - Layer 2

data is organized into frames or packets Handles physical addressing (MAC) and local network flow. Bridges, Switches

Network Layer - Layer 3

Logical addressing (IP) and routing. Routers, Layer 3 Switches

Transport Layer - Layer 4

End-to-end connection, reliability, flow control. TCP and UDP. Gateways, Firewalls, PCs

Session Layer - Layer 5

Manages connections between applications like NetBIOS. Gateways, Firewalls.

Presentation Layer - Layer 6

Translates, encrypts, and compresses data SSL/TLS, JPEG

Application Layer - Layer 7

Provides network services directly to user applications like HTTP, DNS. PCs, Servers, Phones, Firewalls

Error Detection

Parity < Checksum < CRC

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.

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.

DOCSIS Data Over Cable Service Interface Specification

A standard that allows high-speed data transfer internet over existing coaxial cable TV lines.

T1/T3 Lines

point-to-point Digital, dedicated, leased line standards, historically used for connecting branch offices to ISPs or WANs

T1

A dedicated line with 24 channels ,DS0s, of 64 Kbps each, providing a total capacity of 1.544 Mbps

T3 / DS3 / E3

A higher-capacity line offering 28 T1 circuits, delivering a total data rate of 44.736 Mbps.

SONET - Synchronous Optical Networking

A standard for transporting high-bandwidth data over fiber-optic networks, commonly used in metropolitan and wide-area networks (WAN). Provides robust redundancy, with self-healing ring topologies to reroute traffic automatically if a cable is cut.

DSL Flavors - Digital Subscriber Line

DSL technologies provide high-speed data transmission over existing, unused copper telephone lines. the local loop.