Data Communications Overview
48 Questions
6 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What does high throughput indicate about network performance?

  • High latency levels
  • Poor data transmission rates
  • Good network performance (correct)
  • Increased packet loss

What does the term 'latency' refer to in networking?

  • The total amount of data transmitted
  • The delay in data packet transmission (correct)
  • The measure of network errors
  • The speed of data packet arrival

In the water analogy for throughput, what does a wide pipe represent?

  • High latency in network performance
  • Network congestion
  • High data flow rate (correct)
  • Low data transmission efficiency

What is commonly measured in round trips to assess latency?

<p>Time taken for an acknowledgment (A)</p> Signup and view all the answers

Which scenario best describes high latency conditions in a network?

<p>Delayed data packets causing lagging services (A)</p> Signup and view all the answers

What may cause high levels of latency in a network?

<p>Narrow pipes or obstacles in data flow (C)</p> Signup and view all the answers

How is throughput typically measured?

<p>In bits per second (bps) (A)</p> Signup and view all the answers

Which of the following describes the impact of low throughput on a network?

<p>Increased packet loss and potential issues (C)</p> Signup and view all the answers

What distinguishes half-duplex communication from full-duplex communication?

<p>Data is transmitted in one direction at a time. (C)</p> Signup and view all the answers

In a four-wire circuit, what is the primary purpose of the separation of transmitting and receiving paths?

<p>To enhance signal integrity and reduce interference. (B)</p> Signup and view all the answers

Which component carries the positive side of the differential signal for receiving in a four-wire circuit?

<p>Receive Data Positive (RD+) (A)</p> Signup and view all the answers

What is a significant characteristic of circuit switching?

<p>It relies on established paths for communication. (D)</p> Signup and view all the answers

Which of the following best describes packet switching?

<p>Data is divided into smaller packets for independent transmission. (B)</p> Signup and view all the answers

What advantage does packet switching provide over circuit switching?

<p>Greater flexibility in data transmission paths. (D)</p> Signup and view all the answers

What role does ground play in half-duplex communication circuits?

<p>Ground is needed to complete the circuit for signals. (A)</p> Signup and view all the answers

How does ground utility differ in four-wire circuits compared to half-duplex systems?

<p>Ground may not be explicitly needed in four-wire circuits. (A)</p> Signup and view all the answers

What is the primary function of the outer metallic wrap in a cable?

<p>To assist in noise cancellation (B)</p> Signup and view all the answers

What does a zero voltage level represent in the Alternative Mark Inversion (AMI) scheme?

<p>Binary 0 (A)</p> Signup and view all the answers

Which frequency range is associated with microwave communication?

<p>300 MHz to 300 GHz (A)</p> Signup and view all the answers

Which of the following describes an advantage of synchronous transmission over asynchronous transmission?

<p>It has a constant time interval of transmission (A)</p> Signup and view all the answers

What is the main characteristic of a point-to-point topology?

<p>Only two hosts are directly connected (B)</p> Signup and view all the answers

In pseudoternary encoding, how is a bit 1 represented?

<p>By a zero voltage level (C)</p> Signup and view all the answers

In bus topology, what issue may arise when multiple hosts send data at the same time?

<p>Data collision (A)</p> Signup and view all the answers

Which statement correctly describes the transmission characteristics of synchronous transmission?

<p>Users must wait for the transmission to complete (D)</p> Signup and view all the answers

What is a key characteristic of Bus topology?

<p>Failure of one device does not affect the rest. (A)</p> Signup and view all the answers

Which of the following is NOT commonly associated with wireless media?

<p>CCTV (D)</p> Signup and view all the answers

What happens if the hub fails in Star topology?

<p>All hosts lose connectivity to one another. (C)</p> Signup and view all the answers

Which of the following is a characteristic of synchronous transmission?

<p>Data is sent in the form of blocks or frames (C)</p> Signup and view all the answers

Which satellite frequency band is primarily used for GPS services?

<p>L-Band (C)</p> Signup and view all the answers

In Ring topology, what is the consequence of a single host failing?

<p>The entire ring fails to function. (B)</p> Signup and view all the answers

What is a disadvantage of synchronous transmission compared to asynchronous transmission?

<p>It requires precise clock synchronization (B)</p> Signup and view all the answers

Which type of wireless communication operates with frequencies just below visible light?

<p>Infrared (D)</p> Signup and view all the answers

Which of the following describes Mesh topology?

<p>Hosts can communicate directly or relay through other hosts. (C)</p> Signup and view all the answers

Which modulation technique is NOT categorized as an analog to digital signal conversion?

<p>Phase Shift Keying (A)</p> Signup and view all the answers

In bipolar schemes, what is the representation of binary 1?

<p>Alternating between positive and negative voltages (D)</p> Signup and view all the answers

What defines network topology?

<p>The arrangement of nodes and links in a network (C)</p> Signup and view all the answers

In the NRZ (Non Return to Zero) encoding scheme, what voltage level is used to represent bit 0?

<p>Zero voltage (A)</p> Signup and view all the answers

What type of cable is typically used in Bus topology?

<p>Coaxial cable or RJ-45 cable (C)</p> Signup and view all the answers

Which of the following is true regarding the economical aspect of transmission methods?

<p>Synchronous transmission is more costly than asynchronous (C)</p> Signup and view all the answers

What is the main reason Star topology is considered less expensive for adding new hosts?

<p>It requires only a small number of cables. (D)</p> Signup and view all the answers

Which of the following schemes has a transition at the middle of each bit but determines bit values at the beginning of the bit?

<p>Differential Manchester (C)</p> Signup and view all the answers

Which encoding scheme uses three voltage levels?

<p>Return to Zero (A)</p> Signup and view all the answers

How does data travel in Ring topology when sending a message to a non-adjacent host?

<p>Through all intermediate hosts sequentially. (D)</p> Signup and view all the answers

Which statement is true regarding the point of failure in various topologies?

<p>In bus topology, the shared communication line is a point of failure. (C)</p> Signup and view all the answers

What does the Polar NRZ-I encoding scheme do when transmitting a logical 1?

<p>Transition occurs at the midpoint of the bit (A)</p> Signup and view all the answers

What is the main characteristic of Manchester encoding?

<p>Transition is at the midpoint of the bit (B)</p> Signup and view all the answers

What type of data encoding does NOT use both positive and negative voltage levels?

<p>Unipolar Encoding (B)</p> Signup and view all the answers

Which of the following encoding schemes has no return to zero and defines bit 0 with a zero voltage level?

<p>Non Return to Zero (C)</p> Signup and view all the answers

Flashcards

Coaxial Cable

A cable with a central copper wire surrounded by an insulator, a copper mesh, and an outer metal wrap for noise cancellation.

Wireless Media

Communication channels that don't use physical cables, relying on electromagnetic waves.

Radio Waves

Electromagnetic waves ranging from 3 kHz to 300 GHz, commonly used in Wi-Fi, Bluetooth and mobile phones.

Microwave

Electromagnetic waves (300MHz-300GHz) commonly used for long-distance communication and satellite links.

Signup and view all the flashcards

Infrared

Electromagnetic waves between visible light and microwaves (300 GHz to 400 THz) used for short-range communication.

Signup and view all the flashcards

Satellite Transmission

A form of wireless communication that uses satellites in orbit to relay signals over large distances.

Signup and view all the flashcards

Point-to-Point Topology

A network topology where communication occurs between exactly two hosts.

Signup and view all the flashcards

Bus Topology

A network topology where all devices share a single communication cable.

Signup and view all the flashcards

Bus Topology

A network topology where all devices are connected to a single cable (bus).

Signup and view all the flashcards

Bus Topology Failure

If the shared communication line fails, all devices on the bus stop functioning.

Signup and view all the flashcards

Star Topology

All hosts connect to a central hub device.

Signup and view all the flashcards

Star Topology Failure

If the hub fails, all devices connected to it lose connectivity.

Signup and view all the flashcards

Ring Topology

Hosts are connected in a circular loop.

Signup and view all the flashcards

Ring Topology Failure

Failure of any host in a ring topology causes the entire network to fail.

Signup and view all the flashcards

Mesh Topology

Hosts are connected to one or multiple other hosts.

Signup and view all the flashcards

Mesh Topology Communication

Hosts can act as relay points for other hosts without a direct connection.

Signup and view all the flashcards

Throughput

The rate at which data is transmitted successfully over a network in a specific period. Measured in bits per second (bps).

Signup and view all the flashcards

High Throughput

Indicates good network performance, allowing high volumes of data to be transferred quickly.

Signup and view all the flashcards

Latency

The time delay for a data packet to reach its destination after transmission.

Signup and view all the flashcards

Low Throughput

Indicates poor network performance, resulting in packet loss or issues.

Signup and view all the flashcards

Network Latency

The delay experienced by data packets in a network.

Signup and view all the flashcards

Two-Wire Circuit

A circuit that uses one wire for signal and one for ground.

Signup and view all the flashcards

Round-Trip Measurement

A common method of measuring network latency by measuring time for a packet to go and come back.

Signup and view all the flashcards

Data Packet

A unit of data transmitted over a network.

Signup and view all the flashcards

Half-duplex Communication

Data transmission in one direction at a time, using the same wires for sending and receiving but not simultaneously.

Signup and view all the flashcards

Four-wire Circuit

Uses two pairs of wires for sending and receiving signals separately. Reduces interference and allows higher transfer rates.

Signup and view all the flashcards

Circuit Switching

Establishes a dedicated communication path for the duration of a session.

Signup and view all the flashcards

Packet Switching

Divides data into packets which travel independently through the network to be reassembled at the destination.

Signup and view all the flashcards

Transmit Data Positive (TD+)

Carries the positive side of the differential signal for transmission in a four-wire circuit.

Signup and view all the flashcards

Transmit Data Negative (TD-)

Carries the negative side of the differential signal for transmission in a four-wire circuit.

Signup and view all the flashcards

Receive Data Positive (RD+)

Carries the positive side of the differential signal for receiving in a four-wire circuit

Signup and view all the flashcards

Receive Data Negative (RD-)

Carries the negative side of the differential signal for receiving in a four-wire circuit.

Signup and view all the flashcards

AMI Encoding

A bipolar signaling method where binary 1s are represented by alternating positive and negative voltages, and 0 is represented by zero voltage.

Signup and view all the flashcards

Pseudoternary Encoding

A bipolar signaling method where 1 is represented by zero voltage, and 0 by alternating positive and negative voltages.

Signup and view all the flashcards

Synchronous Transmission

Data transmitted in blocks, with a constant time interval between transmissions, requiring synchronized clocks.

Signup and view all the flashcards

Asynchronous Transmission

Data transmitted in bytes or characters, with unpredictable time intervals, and incorporating start/stop bits.

Signup and view all the flashcards

Synchronous Transmission Speed

Faster transmission due to continuous data flow without gaps.

Signup and view all the flashcards

Asynchronous Transmission Cost

More economical since transmission is not always active.

Signup and view all the flashcards

Asynchronous Start/Stop Bits

Used in asynchronous transmission; signal the start and end of a character; adds overhead.

Signup and view all the flashcards

Synchronous Transmission Synchronization

Needs precisely synchronized clocks for successful data transmission.

Signup and view all the flashcards

NRZ Encoding

Non-Return to Zero encoding; a digital signal encoding scheme where the signal level stays at a constant value for the duration of a bit, and doesn't return to zero.

Signup and view all the flashcards

Unipolar Encoding

A digital signal encoding method where all signal levels are either above or below the axis.

Signup and view all the flashcards

Polar Encoding

A digital signal encoding scheme where signal levels are on both sides of the axis.

Signup and view all the flashcards

NRZ-L Encoding

Non-Return to Zero Level; The level of the voltage determines the bit value. Typically a high level represents a binary 1, and a low level represents a binary 0.

Signup and view all the flashcards

NRZ-I Encoding

Non-Return to Zero Invert; a transition at the bit boundary indicates a binary 1; otherwise, it represents a binary 0.

Signup and view all the flashcards

RZ Encoding

Return to Zero: signal returns to zero in the middle of each bit.

Signup and view all the flashcards

Manchester Encoding

Transition in the middle of each bit indicates the bit value; a transition from low to high represents 1, a high-to-low transition represents 0.

Signup and view all the flashcards

Differential Manchester Encoding

Transition at the mid-bit, but the value of the bit depends on whether there's a transition at the start of the bit

Signup and view all the flashcards

Study Notes

Data Communications

  • Data communication is the process of transferring data from one place to another or between two locations.
  • It involves the conversion of data into signals that can be transmitted and received.
  • Data communication systems consist of components such as the sender, receiver, message, protocols, and transmission medium.

Basic Components of Data Communication Systems

  • Message: Piece of information to be transmitted (e.g., text, audio, video).
  • Sender: Device that sends data messages.
  • Receiver: Device that receives messages.
  • Protocols: Set of rules that define how data is transmitted and communicated.
  • Communication channels: Medium connecting devices (e.g., workstations).

Data Communication Models

  • OSI Model: Seven-layer model for transmitting data over the internet.
  • TCP/IP Model: Four-layer model that predates the OSI model.

Types of Data Transmission

  • Serial Communication: Data transmitted one bit at a time, single communication line. Used for long distances.
  • Parallel Communication: Multiple bits transmitted simultaneously on separate wires. Used for short distances where speed is important, example printers, external hard drives. Data is sent in groups of 8 bits.

Communication Channels

  • Wired Media: Includes Twisted-Pair cable, Fiber Optic cable, and Coaxial cable.
  • Wireless Media: Includes Radio, Microwaves, Infrared, and Satellite communication.

Network Topologies

  • Point-to-Point: Two hosts connected via a single cable. Failure of one host doesn't usually affect the other hosts.
  • Bus Topology: All hosts share a single communication line/cable. Hosts send data at the same time. It can have problems communicating at the same time. Failure in one host will not always affect other hosts on the network.
  • Star Topology: Hosts are connected to a central device, referred to as a hub. Hosts send data to the central host. Easier to add new hosts to the network.
  • Ring Topology: Every host connects with two other hosts, in a circular fashion. Messages must circulate through all connected hosts to get to the correct host. Failure of one host can cause a failure of the entire system.
  • Mesh Topology: One or more hosts can be connected to every other host. All hosts have dedicated pathways for transmitting data and redundancy improves reliability.

Transmission Modes

  • Simplex: One-way communication (e.g., broadcasting).
  • Half-duplex: Two-way communication, but only one direction at a time (e.g., walkie-talkie).
  • Full-duplex: Two-way communication simultaneously in both directions.

Data Encoding

  • Unipolar: Signal is either positive or zero voltage.
  • Polar: Voltage alternates between positive and negative, binary signals.
  • Bipolar: Three voltage levels (positive, negative, zero) to represent bits.

Synchronization Methods

  • Synchronous Transmission: Data is sent in blocks, constant time interval, more accurate but slower than Asynchronous transmission.
  • Asynchronous Transmission: Data sent as bytes, time interval is not fixed, transmission time is economical. Time interval is random.

Errors

  • Errors detected and corrected in real time (e.g., video conferencing)
  • Errors detected when data is received (e.g., email)

Latency

  • Delay of data packet to reach destination.
  • High latency means longer delay to reach destination (e.g., large file transfer).

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Data Communications PDF

Description

This quiz explores the fundamental concepts of data communication, covering essential components, models, and types of data transmission. You'll learn about the OSI and TCP/IP models, as well as the roles of senders, receivers, and protocols in effective data transfer. Join us to test your knowledge on this pivotal aspect of networking.

More Like This

Differences between OSI Model and Real World, Data Communication Layers
10 questions

Differences between OSI Model and Real World, Data Communication Layer...

FuturisticShakuhachi7897 avatar
FuturisticShakuhachi7897
OSI Model, TCP, and Data Communication Quiz
10 questions

OSI Model, TCP, and Data Communication Quiz

ProfusePyramidsOfGiza avatar
ProfusePyramidsOfGiza
Data Communication Models and Mediums
8 questions

Data Communication Models and Mediums

SharperHeliotrope3981 avatar
SharperHeliotrope3981
TCP/IP and OSI Model Overview
37 questions

TCP/IP and OSI Model Overview

WellBacklitPalmTree avatar
WellBacklitPalmTree
Use Quizgecko on...
Browser
Open
Browser
Browser