Data Communication Basics Quiz
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What is data communication?

The exchange of data between two devices via some form of transmission medium.

Which of the following is NOT one of the five components of data communication?

  • Receiver
  • Message
  • Transmission medium
  • Encoder (correct)

    • A protocol is a set of rules that governs data communications.

    True

    What is the primary difference between serial and parallel communication?

    <p>Serial communication uses one wire to transfer all bits, while parallel communication uses multiple wires.</p> Signup and view all the answers

    ____ correspond to continuous and discrete in data representation.

    <p>Analog and digital</p> Signup and view all the answers

    Which type of signal is represented by discrete on-off pulses?

    <p>Digital signal</p> Signup and view all the answers

    Which of the following is a popular form of information communicated?

    <p>All of the above</p> Signup and view all the answers

    Which of the following is an example of a transmission medium?

    <p>Twisted-pair wire</p> Signup and view all the answers

    In data communications, the sender is the device that receives the message.

    <p>False</p> Signup and view all the answers

    What is required for data communications to occur?

    <p>A combination of hardware and software.</p> Signup and view all the answers

    The _____ is a set of rules that govern data communications.

    <p>protocol</p> Signup and view all the answers

    What is the role of the receiver in data communication?

    <p>To accept and process the incoming message</p> Signup and view all the answers

    Match each component of data communication with its definition:

    <p>Message = The information to be communicated Sender = The device that sends the data Receiver = The device that receives the data Transmission Medium = The physical path for the message</p> Signup and view all the answers

    Protocols are not necessary for communication between two devices.

    <p>False</p> Signup and view all the answers

    Examples of popular forms of information communicated include text, numbers, and _____ .

    <p>pictures</p> Signup and view all the answers

    What is the primary cause of thermal noise?

    <p>Thermal agitation of electrons</p> Signup and view all the answers

    Delay distortion can be defined as a phenomenon where signal velocity and frequency remain constant.

    <p>False</p> Signup and view all the answers

    What does the term 'crosstalk' refer to in communication?

    <p>Unwanted coupling between signal paths</p> Signup and view all the answers

    In data transmission, a ______ connection allows data to flow in only one direction.

    <p>simplex</p> Signup and view all the answers

    Match the types of noise with their descriptions:

    <p>Thermal noise = Caused by thermal agitation of electrons Impulse noise = Consists of irregular pulses of short duration Intermodulation noise = Results from signals at different frequencies sharing the same medium Crosstalk = Unwanted coupling between signal paths</p> Signup and view all the answers

    Which of the following components is considered a major limiting factor in communications system performance?

    <p>Noise</p> Signup and view all the answers

    Attenuation is the same for all frequencies.

    <p>False</p> Signup and view all the answers

    What technique can be used to address the effects of delay distortion?

    <p>Equalizing techniques</p> Signup and view all the answers

    What is the key to Code Division Multiple Access (CDMA)?

    <p>Extracting the desired signal while rejecting others as noise</p> Signup and view all the answers

    Statistical multiplexing eliminates the issue of empty segments in the output stream.

    <p>True</p> Signup and view all the answers

    What is the chip sequence used for in CDMA?

    <p>To encode transmitted bits uniquely for each station.</p> Signup and view all the answers

    In CDMA, to transmit a 0 bit, a station sends the ______ of its chip sequence.

    <p>negation</p> Signup and view all the answers

    In the example provided, what operation is performed to find the common channel?

    <p>Multiply data by their respective codes</p> Signup and view all the answers

    Which of the following describes a half-duplex connection?

    <p>Data flows in one direction at a time.</p> Signup and view all the answers

    In a full-duplex connection, both devices can send and receive data at the same time.

    <p>True</p> Signup and view all the answers

    Match the following elements of CDMA to their descriptions:

    <p>Chip sequence = Unique code assigned to a station Data transmission = Sending bits encoded by chip sequences Multiplexing = Combining signals from multiple sources Demultiplexing = Extracting specific signals from combined data</p> Signup and view all the answers

    Errors in transmitted data can only occur due to equipment failure.

    <p>False</p> Signup and view all the answers

    Name one common example of a full-duplex communication system.

    <p>Telephone network</p> Signup and view all the answers

    What is one common method used for error detection in data transmission?

    <p>Checksums or parity bits.</p> Signup and view all the answers

    A half-duplex connection is also known as an __________ connection.

    <p>alternating</p> Signup and view all the answers

    Match the following types of connections with their descriptions:

    <p>Half-Duplex = Data flows in one direction at a time Full-Duplex = Data flows in both directions simultaneously Multiplexing = Sharing a single medium for multiple communications</p> Signup and view all the answers

    What is multiplexing in data communication?

    <p>Sharing a single medium for multiple communications.</p> Signup and view all the answers

    In a half-duplex communication system, the entire capacity of the channel can be utilized for each direction.

    <p>True</p> Signup and view all the answers

    What do walkie-talkies and CB radios have in common regarding their connection type?

    <p>They are both half-duplex systems.</p> Signup and view all the answers

    What is one common cause of errors in optical fibers?

    <p>Dispersion of light pulses</p> Signup and view all the answers

    What is the result of a Hamming distance of 1?

    <p>One character has a single error</p> Signup and view all the answers

    What is the purpose of adding a parity bit to a character?

    <p>To ensure the number of bits is even or odd.</p> Signup and view all the answers

    The minimum number of substitutions required to change one bit pattern into another is known as the __________.

    <p>Hamming distance</p> Signup and view all the answers

    Match the types of parity with their definitions:

    <p>Odd Parity = Number of 1s in the bit pattern is odd Even Parity = Number of 1s in the bit pattern is even</p> Signup and view all the answers

    Parity checking can detect double errors in a character.

    <p>False</p> Signup and view all the answers

    What is thermal noise in the context of data transmission?

    <p>Natural interference that causes errors in signals.</p> Signup and view all the answers

    Errors in data transmission can be completely eliminated with current technology.

    <p>False</p> Signup and view all the answers

    Study Notes

    Data Communication Basics

    • Data communication is the exchange of data between two or more devices, using a medium like a wire cable.
    • It involves the transfer of data from one location to another using computing and communication technologies.
    • A communication system consists of hardware (physical equipment) and software (programs) that work together to enable data communication.

    Components of a Communication System

    • Message: The information being communicated, such as text, numbers, pictures, audio, or video.
    • Sender: The device sending the message, like a computer, workstation, phone, or video camera.
    • Receiver: The device receiving the message, like a computer, workstation, phone, or television.
    • Transmission Medium: The physical path the message travels, including wires, cables, and radio waves.
    • Protocol: A set of rules governing communication between devices. This ensures both devices understand and can process the transmitted data.

    Serial vs. Parallel Communication

    • Parallel Communication:
      • More expensive to implement because it requires multiple wires to transfer multiple bits simultaneously.
      • Usually used for short-distance communication because it's more complex.
      • Offers faster data transfer speeds.
    • Serial Communication:
      • Less expensive than parallel because it requires fewer wires.
      • Easier to implement.
      • More suitable for long-distance communication.
      • Slower transfer speeds.
      • Requires less complex hardware.

    Communication Tasks

    • Data communication systems must perform several tasks to ensure successful communication:
      • Encoding and Decoding: Converting data into a format suitable for transmission and decoding it back to its original form at the receiving end.
      • Addressing: Identifying the sender and receiver for accurate delivery of the message.
      • Routing: Determining the best path for the data to travel between sender and receiver.
      • Flow Control: Regulating the rate of data transmission to avoid overwhelming the receiver.
      • Error Control: Detecting and correcting errors that may occur during transmission.
      • Security: Protecting the data from unauthorized access and modification.
      • Synchronization: Ensuring both devices are in agreement about the timing of data transmission.

    Data Representation

    • Analog Signal: A continuous wave that uses variations in its characteristics (like amplitude or frequency) to carry information.
      • Examples include sound waves and radio waves.
      • Measured and can have infinitely many levels of intensity.
    • Digital Signal: A discrete signal representing data in the form of 0s and 1s (binary format).
      • Processed by computers and other digital devices.
      • Counted and has discrete levels.

    Analog vs. Digital Representation

    • Analog Data: Information represented as continuous waves, like sound or video.

    • Digital Data: Information represented using 0s and 1s.

    • Analog Signaling: Using analog signals to carry information like sound or radio waves.

    • Digital Signaling: Using digital signals (0s and 1s) to represent information.

    • Analog Transmission: Sending signals through a medium like a wire cable.

    • Digital Transmission: Sending signals digitally using 0s and 1s across a medium like a network.

    • Note: Analog and digital data/signals can both be transferred over suitable transmission media. The choice of how signals are treated depends on the specific transmission system.

    Data Communication Basics

    • Data communication is the exchange of information between two devices through a transmission medium like a wire cable.
    • It involves using computing and communication technologies for data transfer.
    • Communication systems consist of hardware and software components working together.

    Components of Data Communication

    • Message: The information to be transmitted. It can be in the form of text, numbers, images, audio, or video.
    • Sender: The device originating the message.
    • Receiver: The device that receives the message.
    • Transmission Medium: The physical path by which the message travels. Examples include twisted-pair wire, coaxial cable, fiber optic cable, and radio waves.
    • Protocol: A set of rules that govern data communication, ensuring agreement between communicating devices.

    Transmission Media:

    • Twisted-Pair Wire: Two insulated wires twisted together to reduce interference. This is commonly used for telephone lines and Ethernet networks.
    • Coaxial Cable: A single central wire surrounded by insulation, braid, and a sheath, offering better bandwidth and resistance to interference than twisted-pair. Used for cable television and high-speed internet connections.
    • Fiber Optic Cable: Uses light pulses to transmit data through thin glass or plastic fibers, providing high bandwidth, immunity to interference, and long-distance capabilities. Used for high-speed internet and backbone networks.
    • Radio Waves: Electromagnetic waves that travel through the air, commonly used for wireless communication like Wi-Fi, Bluetooth, and mobile networks.
    • Microwaves: High-frequency radio waves used for satellite communication and long-distance terrestrial links.
    • Satellite Communication: Uses satellites orbiting Earth to relay data between Earth stations. Used for broadcast television, internet access, and mobile phone communication.
    • Infrared: Uses infrared light waves for short-range communication, commonly used for remote controls and data transfer between devices.

    Network Protocol Stacks

    • A layered set of protocols that define communication standards at different levels.
    • Each layer handles specific aspects of data communication, like addressing, routing, flow control, or error detection.
    • The most common protocol stack is TCP/IP (Transmission Control Protocol/Internet Protocol).

    Transmission Impairments

    • Attenuation: Signal strength weakens as it travels through a medium.
    • Distortion: Changes in the original signal's shape or frequency components during transmission.
    • Delay Distortion: Occurs when different frequency components of a signal travel at different speeds, leading to phase shifts.
    • Noise: Unwanted signals interfering with the desired signal.
    • Thermal Noise: Generated by the random movement of electrons in conductors.
    • Intermodulation Noise: Occurs when signals at different frequencies share the same transmission medium, leading to interference.
    • Crosstalk: Unwanted coupling between signal paths.
    • Impulse Noise: Short-duration noise spikes of high amplitude.

    Modes of Data Transmission

    • Simplex: Data flows in one direction only. Examples include from computer to printer or mouse to computer.
    • Half-Duplex: Data flows in one direction at a time, alternating between sender and receiver. Walkie-talkies are an example.
    • Full-Duplex: Data flows in both directions simultaneously. Telephone networks are an example.

    Multiplexing

    • Enables multiple communication signals to share a single transmission medium.
    • Frequency Division Multiplexing (FDM): Divides the bandwidth into frequency bands allocated to each signal.
    • Time Division Multiplexing (TDM): Divides time into time slots allocated to each signal.
    • Statistical Multiplexing: Allows multiple signals to share a single channel dynamically by allocating time slots based on data transfer needs.
    • Code Division Multiplexing (CDM): Uses unique coding to separate different signals sharing the same frequency band.

    Data Transmission: Error Detection and Correction

    • Errors in transmitted data can arise from equipment failure, signal dispersion, attenuation, or noise.
    • Error Detection: Detects errors in received data.
    • Parity Checking: Appends an extra bit to the data to ensure an even or odd number of '1' bits. This detects a single error.
    • Hamming Distance: Measures the minimum number of bit flips required to transform one binary sequence into another. A Hamming distance of 2 or more ensures that single-bit errors can be detected.
    • Checksums: Calculate a value based on the data and append it. The receiver recalculates the checksum and compares it to the received value to detect errors.
    • Cyclic Redundancy Check (CRC): Uses polynomial division to calculate a checksum. CRC is more robust than simpler checksum methods.
    • Error Correction: Corrects detected errors without retransmission.
    • Hamming Code: Adds redundant bits to data to enable error correction. The code contains enough information to identify and correct specific errors.

    Network Topologies

    • Bus Topology: All devices connect to a single shared cable.
    • Star Topology: All devices connect to a central hub or switch.
    • Ring Topology: Devices are connected in a closed loop.
    • Mesh Topology: Each device has a direct connection to every other device.
    • Tree Topology: A hierarchical structure with a central hub.

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    Description

    Test your knowledge on the fundamentals of data communication. This quiz covers key components such as messages, senders, receivers, transmission mediums, and protocols. Enhance your understanding of how data is exchanged between devices effectively.

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