Wireless Communication Chapter 4
48 Questions
0 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 is the primary purpose of channel encoding in wireless communication?

  • To enhance the speed of data transmission
  • To encrypt the signal for security
  • To reduce the size of the data packet
  • To introduce redundancy for noise resilience (correct)

Which of the following modulation techniques is NOT mentioned in the content?

  • Frequency Shift Keying (FSK)
  • Phase Shift Keying (PSK)
  • Pulse Amplitude Modulation (PAM) (correct)
  • Quadrature Phase Shift Keying (QPSK)

What does the reception path of a wireless communication system primarily involve?

  • Signal generation and channel encoding
  • Demodulation and source decoding of signals (correct)
  • Transmission and encoding of data
  • Multiplexing and encryption of signals

What are some common challenges faced by a wireless communication channel?

<p>Interference, distortion, and noise (B)</p> Signup and view all the answers

Which process occurs immediately after a signal is received by a demultiplexer?

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

What is a key function of the encryption process in signal transmission?

<p>To prevent unauthorized access to the signal (B)</p> Signup and view all the answers

What component follows demodulation in the reception path to ensure the original message is retrieved?

<p>Redundant bit removal (B)</p> Signup and view all the answers

In which stage of the communication process is the signal encrypted?

<p>Before signal transmission (D)</p> Signup and view all the answers

What is the primary function of the transmitter in wireless communication?

<p>To send signals to the receiver. (D)</p> Signup and view all the answers

Which of the following statements about the electromagnetic spectrum is true?

<p>Different technologies utilize specific frequency bands. (D)</p> Signup and view all the answers

What occurs when two wireless devices communicate on the same frequency?

<p>There is a risk of collision or interference. (B)</p> Signup and view all the answers

What do devices using the IEEE 802.11 standard check before transmission?

<p>Whether the channel is available and clear. (B)</p> Signup and view all the answers

How is wireless communication characterized in terms of data transmission?

<p>It is generally conducted in half duplex mode. (A)</p> Signup and view all the answers

How is frequency defined in the context of electromagnetic waves?

<p>The number of electromagnetic waves in one second. (B)</p> Signup and view all the answers

What wavelength value corresponds to a frequency of 1 MHz?

<p>1 meter. (C)</p> Signup and view all the answers

What frequency defines microwaves according to the content provided?

<p>More than 1 GHz. (C)</p> Signup and view all the answers

What is the primary benefit of using hexagonal cell shapes in cellular networks?

<p>They provide more efficient frequency reuse and easier calculations. (C)</p> Signup and view all the answers

Which of the following statements about the shape of cells in cellular networks is incorrect?

<p>Hexagonal cells guarantee precise geometrical shapes in all conditions. (C)</p> Signup and view all the answers

How does frequency reuse work in cellular networks?

<p>It establishes communication by using the same frequencies separated by significant distance. (C)</p> Signup and view all the answers

What defines the distance between centers of hexagonal cells in a cellular network?

<p>Three times the circum-circle radius. (B)</p> Signup and view all the answers

What is typically NOT an aspect addressed by the design of cellular network cells?

<p>Ensuring uniform shape across topographical variations. (C)</p> Signup and view all the answers

In what scenario would square cell shapes be preferred over hexagonal shapes?

<p>When existing infrastructure aligns more naturally with square geometry. (D)</p> Signup and view all the answers

What is a key characteristic of a cellular network base station?

<p>It consists of a transmitter, receiver, and control unit. (D)</p> Signup and view all the answers

Which best describes the function of adjacent cells in a cellular network's design?

<p>They must utilize different frequencies to prevent crosstalk. (D)</p> Signup and view all the answers

What is the primary benefit of Space Division Multiple Access (SDMA)?

<p>It completely eliminates interference. (C)</p> Signup and view all the answers

How does CDMA manage its air-space capacity compared to TDMA?

<p>CDMA can handle a greater number of simultaneous users. (D)</p> Signup and view all the answers

Which statement best describes a cellular network’s approach to data transmission?

<p>Base stations are responsible for coordinating the transmission between mobile devices. (D)</p> Signup and view all the answers

What is a key feature that allows cellular systems to increase user capacity?

<p>Utilizing the same frequency channels in different cells. (C)</p> Signup and view all the answers

What role do directional spot-beam antennas play in SDMA?

<p>They allow base stations to track moving users effectively. (D)</p> Signup and view all the answers

What problem do wireless cellular systems primarily aim to solve?

<p>Spectral congestion in communication channels. (D)</p> Signup and view all the answers

What are the two main components of a Mobile Station (MS)?

<p>Mobile Equipment (ME) and Subscriber Identity Module (SIM) (B)</p> Signup and view all the answers

How is user data communicated between the Mobile Station and the Base Station?

<p>Via the air interface utilizing specific transmission protocols (D)</p> Signup and view all the answers

How are channel groups organized in cellular networks?

<p>Channel groups are allocated to each base station within a small cell area. (C)</p> Signup and view all the answers

What is the main consequence of limiting the coverage area within the cell in cellular systems?

<p>It facilitates the reuse of channel groups in different cells. (C)</p> Signup and view all the answers

What role does the Subscriber Identity Module (SIM) play in mobile telephony?

<p>Identifies user specifications such as address and service type (A)</p> Signup and view all the answers

Which component is responsible for transmitting and receiving user data from multiple subscribers?

<p>Base Station (BS) (B)</p> Signup and view all the answers

What is the primary function of the Mobile Switching Center (MSC)?

<p>To manage the registration and maintenance of mobile connections (A)</p> Signup and view all the answers

Which subsystem within the network is essential for communication between PSTN switches and MSCs?

<p>Signaling System 7 (SS7) (B)</p> Signup and view all the answers

What function does a Base Transceiver Station (BTS) serve in a mobile telecommunications infrastructure?

<p>Facilitates the air interface for data transmission over the network (B)</p> Signup and view all the answers

Which of the following statements about the Mobile Equipment (ME) is incorrect?

<p>ME refers only to software applications for mobile devices. (B)</p> Signup and view all the answers

What is the main purpose of using TDMA in communication systems?

<p>To allocate unique time slots to each user on the same channel (B)</p> Signup and view all the answers

Which statement correctly describes the operational feature of FDMA?

<p>FDMA provides each user with a separate sub-band of frequency access. (C)</p> Signup and view all the answers

What is a disadvantage of using FDMA compared to TDMA?

<p>FDMA deals with adjacent channel interference more significantly. (A)</p> Signup and view all the answers

In contrast to TDMA, how does CDMA manage the allocation of transmission resources?

<p>All users transmit simultaneously using the entire spectrum. (C)</p> Signup and view all the answers

Which of the following best explains the advantages of using wideband systems over narrowband systems?

<p>Multipath fading affects wideband systems less than narrowband systems. (C)</p> Signup and view all the answers

What aspect of TDMA simplifies the handoff process between mobile units?

<p>The allocation of time slots enables clear communication. (A)</p> Signup and view all the answers

Why might CDMA be preferred for voice communications over other methods?

<p>CDMA minimizes the possibility of adjacent channel interference. (C)</p> Signup and view all the answers

What characteristic differentiates the transmission methods of TDMA and FDMA?

<p>TDMA transmits in bursts while FDMA supports continuous transmission. (B)</p> Signup and view all the answers

Flashcards

Electromagnetic Spectrum

Range of frequencies for electromagnetic waves, from radio waves to gamma rays.

Wireless Communication

Transmitting data using electromagnetic waves without physical connections.

Transmitter

Device that sends signals in wireless communication.

Receiver

Device that receives signals in wireless communication.

Signup and view all the flashcards

Half Duplex

Communication mode where devices transmit and receive at different times using the same channel.

Signup and view all the flashcards

Full Duplex

Communication mode allowing simultaneous transmission and reception using different channels.

Signup and view all the flashcards

Frequency

Number of electromagnetic cycles per second, measured in Hertz (Hz).

Signup and view all the flashcards

Wavelength

Distance covered by one complete cycle of an electromagnetic wave.

Signup and view all the flashcards

Cellular Network

A communication system using multiple low power transmitters divided into cells.

Signup and view all the flashcards

Cell Structure

Area divided into cells, each with its own antenna and frequency range.

Signup and view all the flashcards

Base Station

The central unit in a cell comprising transmitter, receiver, and control unit.

Signup and view all the flashcards

Cell Shapes

Cells can be shaped like squares or hexagons for coverage and distance efficiency.

Signup and view all the flashcards

Hexagonal Cells

Recommended cell shape due to equal distance between antennas, facilitating easy calculations.

Signup and view all the flashcards

Square Cells

Cell shape with four neighbors, generally less efficient than hexagonal cells.

Signup and view all the flashcards

Frequency Reuse

Using the same frequencies in different cells set apart by distance to reduce interference.

Signup and view all the flashcards

Radius in Hexagons

In hexagonal cells, the distance between cell centers is defined as three times the radius of the circum-circle.

Signup and view all the flashcards

Encryption Standard

A method used to secure signals from unauthorized access.

Signup and view all the flashcards

Channel Encoding

A technique to reduce impairments by adding redundancy to a signal.

Signup and view all the flashcards

Modulation Technique

Methods like PSK, FSK, QPSK that prepare a signal for transmission.

Signup and view all the flashcards

Multiplexing Techniques

Methods like TDM and FDM that combine multiple signals for transmission.

Signup and view all the flashcards

Wireless Channel

The medium for transmitting wireless signals, often unpredictable and variable.

Signup and view all the flashcards

Reception Path

The process involving demultiplexing, demodulation, and decoding to retrieve the signal.

Signup and view all the flashcards

Demodulation

The process of converting modulated signals back to original data.

Signup and view all the flashcards

Decryption

The process of turning encrypted signals back into readable bits.

Signup and view all the flashcards

CDMA

Code Division Multiple Access is a technique that allows multiple users to occupy the same channel simultaneously.

Signup and view all the flashcards

TDMA

Time Division Multiple Access is a method where users share the same frequency channel by dividing it into time slots.

Signup and view all the flashcards

SDMA

Space Division Multiple Access is a technique that allows multiple users to communicate at the same time using the same channel via spatial separation.

Signup and view all the flashcards

Spectral Congestion

The issue that arises when there are too many signals in the same frequency band, leading to interference.

Signup and view all the flashcards

Interference Levels

The amount of disruption caused by signals from different sources, affecting communication quality.

Signup and view all the flashcards

Mobile Station (MS)

A device that communicates user information with BSS and modifies it for transmission protocols.

Signup and view all the flashcards

Mobile Equipment (ME)

Hardware purchased by the customer that implements protocols to interface users with the air interface.

Signup and view all the flashcards

Subscriber Identity Module (SIM)

A smart card that identifies user specifications and stores personal information like calls and SMS.

Signup and view all the flashcards

Base Station (BS)

Transmits and receives user data and can handle multiple subscribers simultaneously.

Signup and view all the flashcards

Base Transceiver Station (BTS)

Facilitates user data transmission between mobile devices and the base station.

Signup and view all the flashcards

Mobile Switching Center (MSC)

Hardware that connects PSTN switches, communicates with other MSCs, and supports mobile connections.

Signup and view all the flashcards

Signaling System 7 (SS7)

Protocol used by MSC for communication with PSTN and other networks.

Signup and view all the flashcards

Network Sub-System

Includes components like HLR, VLR, EIR, and AuC to manage mobile network operations.

Signup and view all the flashcards

Narrowband

A system allowing a small number of users to share the same channel using unique time slots.

Signup and view all the flashcards

Wideband Systems

Systems where channel bandwidth exceeds coherence bandwidth, reducing the effect of multipath fading.

Signup and view all the flashcards

Frequency Division Multiple Access (FDMA)

A technology that assigns different frequency sub-bands to each user for network access.

Signup and view all the flashcards

Idle Channel in FDMA

FDMA leaves channels idle when not in use, instead of reallocating them.

Signup and view all the flashcards

Time Division Multiple Access (TDMA)

Allows users to share a channel by using non-overlapping time slots for transmission.

Signup and view all the flashcards

Advantages of TDMA

TDMA simplifies handoff and doesn't require duplexers due to time-separated transmissions.

Signup and view all the flashcards

Code Division Multiple Access (CDMA)

Allows multiple users to send information simultaneously using the same channel through unique codes.

Signup and view all the flashcards

CDMA for Voice and Data

CDMA is preferred for both voice and data communication as it utilizes the full spectrum.

Signup and view all the flashcards

Study Notes

Chapter-4: Fundamental Concepts of Wireless Communication

  • Wireless communication is an advanced branch of communication engineering.
  • Wireless communication involves transferring information over a distance without the aid of wires, cables, or other electrical conductors.
  • Wireless communication is a broad term encompassing various procedures and formats for connecting and communicating between two or more devices using a wireless signal.
  • Wireless communication systems transmit information from a transmitter to a receiver over a specific distance.
  • This distance can range from a few meters (e.g., TV remote control) to thousands of kilometers (e.g., satellite communication).
  • Wireless communication is crucial in modern life, enabling technologies such as mobile phones, GPS receivers, remote controls, Bluetooth audio, and Wi-Fi devices.

Outline

  • Overview of Wireless Communication
  • Wireless Communication - Advantages vs. Disadvantages
  • Basic Elements of a Wireless Communication System
  • Electromagnetic Spectrum in Wireless Communication
  • Terms in Mobile Telephony
  • Wireless Communication - Multiple Access
  • Overview of Cellular Systems

Overview of Wireless Communication

  • Wireless communication is an advanced branch of communication engineering.
  • Wireless communication involves transmitting information across distances without needing physical wires or cables.
  • Wireless communication encompasses various methods of connecting and communicating between devices via a wireless signal.

Wireless Communication - Advantages

  • Cost-effectiveness: Wireless communication typically involves lower costs than wired communication because it does not require extensive physical infrastructure.
  • Flexibility: Unlike wired communication, wireless communication does not constrain users to specific locations or settings.
  • Convenience: Wireless devices are generally compact and easy to use, enabling wider accessibility for many users.
  • Speed: Improvements have made wireless communication faster and more reliable than its predecessors.
  • Accessibility: Wireless communication can cover remote areas where installing wired infrastructure might be costly or impossible, thus improving access.

Wireless Communication - Disadvantages

  • Interference: Signals from different wireless devices can interfere with each other.
  • Security: Information transmitted wirelessly can be intercepted by unauthorized individuals.
  • Health concerns: Continuous exposure to radio frequency (RF) radiation from wireless devices might pose some health dangers; though, the concern is still under study.

Basic Elements of a Wireless Communication System

  • A typical wireless communication system consists of three main components:
    • Transmitter
    • Channel
    • Receiver

Electromagnetic Spectrum in Wireless Communication

  • The electromagnetic spectrum encompasses a wide range of frequencies, from low-frequency radio waves to high-frequency gamma rays.
  • Different wireless communication technologies utilize different specific frequency bands, each offering distinct benefits for propagation characteristics, coverage, and bandwidth.

Terms in Mobile Telephony

  • Mobile Station (MS): Communicates with the user and modifies the transmit protocol to communicate with the Base Station Subsystem (BSS).
  • Mobile Equipment (ME): The hardware piece purchased by the customer; it implements the protocols and connects to the user's interface and base stations.
  • Subscriber Identity Module (SIM): A smart card holding user data and specifications.
  • Base Station (BS): Transmits and receives user data; it manages and handles calls from multiple subscribers.
  • Base Transceiver Station (BTS): Facilitates communication between mobile phones and the base station through a specific, dedicated wireless channel.
  • Mobile Switching Center (MSC): Hardware responsible for connecting with Public Switched Telephone Network (PSTN) switches using the Signaling System 7 (SS7) protocol.

Wireless Communication - Multiple Access

  • Multiple access techniques enable multiple users to share a common radio spectrum simultaneously.
  • Techniques such as Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), and Space Division Multiple Access (SDMA) are used for this.

Overview of Cellular Systems

  • Cellular networks use radio technologies to improve telecommunications, and mobile communications.
  • These techniques increase efficiency and handle multiple users and connections simultaneously.

Frequency Reuse

  • Frequency reuse is a critical concept in cellular technologies.
  • It involves reusing the same frequency channel in different cells to accommodate as many users as possible.
  • However, in order to maintain clear communication, adequate separation between frequencies is used.

Studying That Suits You

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

Quiz Team

Related Documents

Chapter-4 Fundamental Concepts of Wireless Communication PDF

Description

Explore the fundamental concepts of wireless communication in this quiz. Learn about how wireless systems operate, their advantages and disadvantages, and the basic elements involved in wireless communication. This chapter is essential for understanding modern communications technologies.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser